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sessiond: refactoring: introduce start/stop_kernel_session
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25 #include <stdio.h>
26
27 #include <common/defaults.h>
28 #include <common/common.h>
29 #include <common/sessiond-comm/sessiond-comm.h>
30 #include <common/relayd/relayd.h>
31 #include <common/utils.h>
32 #include <common/compat/string.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/dynamic-buffer.h>
35 #include <common/buffer-view.h>
36 #include <common/trace-chunk.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/trigger/trigger-internal.h>
39 #include <lttng/condition/condition.h>
40 #include <lttng/action/action.h>
41 #include <lttng/channel.h>
42 #include <lttng/channel-internal.h>
43 #include <lttng/rotate-internal.h>
44 #include <lttng/location-internal.h>
45 #include <lttng/session-internal.h>
46 #include <lttng/userspace-probe-internal.h>
47 #include <lttng/session-descriptor-internal.h>
48 #include <common/string-utils/string-utils.h>
49
50 #include "channel.h"
51 #include "consumer.h"
52 #include "event.h"
53 #include "health-sessiond.h"
54 #include "kernel.h"
55 #include "kernel-consumer.h"
56 #include "lttng-sessiond.h"
57 #include "utils.h"
58 #include "lttng-syscall.h"
59 #include "agent.h"
60 #include "buffer-registry.h"
61 #include "notification-thread.h"
62 #include "notification-thread-commands.h"
63 #include "rotate.h"
64 #include "rotation-thread.h"
65 #include "timer.h"
66 #include "agent-thread.h"
67
68 #include "cmd.h"
69
70 /* Sleep for 100ms between each check for the shm path's deletion. */
71 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
72
73 struct cmd_destroy_session_reply_context {
74 int reply_sock_fd;
75 bool implicit_rotation_on_destroy;
76 /*
77 * Indicates whether or not an error occurred while launching the
78 * destruction of a session.
79 */
80 enum lttng_error_code destruction_status;
81 };
82
83 static enum lttng_error_code wait_on_path(void *path);
84
85 /*
86 * Command completion handler that is used by the destroy command
87 * when a session that has a non-default shm_path is being destroyed.
88 *
89 * See comment in cmd_destroy_session() for the rationale.
90 */
91 static struct destroy_completion_handler {
92 struct cmd_completion_handler handler;
93 char shm_path[member_sizeof(struct ltt_session, shm_path)];
94 } destroy_completion_handler = {
95 .handler = {
96 .run = wait_on_path,
97 .data = destroy_completion_handler.shm_path
98 },
99 .shm_path = { 0 },
100 };
101
102 static struct cmd_completion_handler *current_completion_handler;
103
104 /*
105 * Used to keep a unique index for each relayd socket created where this value
106 * is associated with streams on the consumer so it can match the right relayd
107 * to send to. It must be accessed with the relayd_net_seq_idx_lock
108 * held.
109 */
110 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
111 static uint64_t relayd_net_seq_idx;
112
113 static int validate_ust_event_name(const char *);
114 static int cmd_enable_event_internal(struct ltt_session *session,
115 const struct lttng_domain *domain,
116 char *channel_name, struct lttng_event *event,
117 char *filter_expression,
118 struct lttng_filter_bytecode *filter,
119 struct lttng_event_exclusion *exclusion,
120 int wpipe);
121
122 /*
123 * Create a session path used by list_lttng_sessions for the case that the
124 * session consumer is on the network.
125 */
126 static int build_network_session_path(char *dst, size_t size,
127 struct ltt_session *session)
128 {
129 int ret, kdata_port, udata_port;
130 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
131 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
132
133 assert(session);
134 assert(dst);
135
136 memset(tmp_urls, 0, sizeof(tmp_urls));
137 memset(tmp_uurl, 0, sizeof(tmp_uurl));
138
139 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
140
141 if (session->kernel_session && session->kernel_session->consumer) {
142 kuri = &session->kernel_session->consumer->dst.net.control;
143 kdata_port = session->kernel_session->consumer->dst.net.data.port;
144 }
145
146 if (session->ust_session && session->ust_session->consumer) {
147 uuri = &session->ust_session->consumer->dst.net.control;
148 udata_port = session->ust_session->consumer->dst.net.data.port;
149 }
150
151 if (uuri == NULL && kuri == NULL) {
152 uri = &session->consumer->dst.net.control;
153 kdata_port = session->consumer->dst.net.data.port;
154 } else if (kuri && uuri) {
155 ret = uri_compare(kuri, uuri);
156 if (ret) {
157 /* Not Equal */
158 uri = kuri;
159 /* Build uuri URL string */
160 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
161 if (ret < 0) {
162 goto error;
163 }
164 } else {
165 uri = kuri;
166 }
167 } else if (kuri && uuri == NULL) {
168 uri = kuri;
169 } else if (uuri && kuri == NULL) {
170 uri = uuri;
171 }
172
173 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
174 if (ret < 0) {
175 goto error;
176 }
177
178 /*
179 * Do we have a UST url set. If yes, this means we have both kernel and UST
180 * to print.
181 */
182 if (*tmp_uurl != '\0') {
183 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
184 tmp_urls, kdata_port, tmp_uurl, udata_port);
185 } else {
186 int dport;
187 if (kuri || (!kuri && !uuri)) {
188 dport = kdata_port;
189 } else {
190 /* No kernel URI, use the UST port. */
191 dport = udata_port;
192 }
193 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
194 }
195
196 error:
197 return ret;
198 }
199
200 /*
201 * Get run-time attributes if the session has been started (discarded events,
202 * lost packets).
203 */
204 static int get_kernel_runtime_stats(struct ltt_session *session,
205 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
206 uint64_t *lost_packets)
207 {
208 int ret;
209
210 if (!session->has_been_started) {
211 ret = 0;
212 *discarded_events = 0;
213 *lost_packets = 0;
214 goto end;
215 }
216
217 ret = consumer_get_discarded_events(session->id, kchan->key,
218 session->kernel_session->consumer,
219 discarded_events);
220 if (ret < 0) {
221 goto end;
222 }
223
224 ret = consumer_get_lost_packets(session->id, kchan->key,
225 session->kernel_session->consumer,
226 lost_packets);
227 if (ret < 0) {
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Get run-time attributes if the session has been started (discarded events,
237 * lost packets).
238 */
239 static int get_ust_runtime_stats(struct ltt_session *session,
240 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
241 uint64_t *lost_packets)
242 {
243 int ret;
244 struct ltt_ust_session *usess;
245
246 if (!discarded_events || !lost_packets) {
247 ret = -1;
248 goto end;
249 }
250
251 usess = session->ust_session;
252 assert(discarded_events);
253 assert(lost_packets);
254
255 if (!usess || !session->has_been_started) {
256 *discarded_events = 0;
257 *lost_packets = 0;
258 ret = 0;
259 goto end;
260 }
261
262 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
263 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
264 &usess->buffer_reg_uid_list,
265 usess->consumer, uchan->id,
266 uchan->attr.overwrite,
267 discarded_events,
268 lost_packets);
269 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
270 ret = ust_app_pid_get_channel_runtime_stats(usess,
271 uchan, usess->consumer,
272 uchan->attr.overwrite,
273 discarded_events,
274 lost_packets);
275 if (ret < 0) {
276 goto end;
277 }
278 *discarded_events += uchan->per_pid_closed_app_discarded;
279 *lost_packets += uchan->per_pid_closed_app_lost;
280 } else {
281 ERR("Unsupported buffer type");
282 assert(0);
283 ret = -1;
284 goto end;
285 }
286
287 end:
288 return ret;
289 }
290
291 /*
292 * Fill lttng_channel array of all channels.
293 */
294 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
295 struct ltt_session *session, struct lttng_channel *channels,
296 struct lttng_channel_extended *chan_exts)
297 {
298 int i = 0, ret = 0;
299 struct ltt_kernel_channel *kchan;
300
301 DBG("Listing channels for session %s", session->name);
302
303 switch (domain) {
304 case LTTNG_DOMAIN_KERNEL:
305 /* Kernel channels */
306 if (session->kernel_session != NULL) {
307 cds_list_for_each_entry(kchan,
308 &session->kernel_session->channel_list.head, list) {
309 uint64_t discarded_events, lost_packets;
310 struct lttng_channel_extended *extended;
311
312 extended = (struct lttng_channel_extended *)
313 kchan->channel->attr.extended.ptr;
314
315 ret = get_kernel_runtime_stats(session, kchan,
316 &discarded_events, &lost_packets);
317 if (ret < 0) {
318 goto end;
319 }
320 /* Copy lttng_channel struct to array */
321 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
322 channels[i].enabled = kchan->enabled;
323 chan_exts[i].discarded_events =
324 discarded_events;
325 chan_exts[i].lost_packets = lost_packets;
326 chan_exts[i].monitor_timer_interval =
327 extended->monitor_timer_interval;
328 chan_exts[i].blocking_timeout = 0;
329 i++;
330 }
331 }
332 break;
333 case LTTNG_DOMAIN_UST:
334 {
335 struct lttng_ht_iter iter;
336 struct ltt_ust_channel *uchan;
337
338 rcu_read_lock();
339 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
340 &iter.iter, uchan, node.node) {
341 uint64_t discarded_events = 0, lost_packets = 0;
342
343 if (lttng_strncpy(channels[i].name, uchan->name,
344 LTTNG_SYMBOL_NAME_LEN)) {
345 break;
346 }
347 channels[i].attr.overwrite = uchan->attr.overwrite;
348 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
349 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
350 channels[i].attr.switch_timer_interval =
351 uchan->attr.switch_timer_interval;
352 channels[i].attr.read_timer_interval =
353 uchan->attr.read_timer_interval;
354 channels[i].enabled = uchan->enabled;
355 channels[i].attr.tracefile_size = uchan->tracefile_size;
356 channels[i].attr.tracefile_count = uchan->tracefile_count;
357
358 /*
359 * Map enum lttng_ust_output to enum lttng_event_output.
360 */
361 switch (uchan->attr.output) {
362 case LTTNG_UST_MMAP:
363 channels[i].attr.output = LTTNG_EVENT_MMAP;
364 break;
365 default:
366 /*
367 * LTTNG_UST_MMAP is the only supported UST
368 * output mode.
369 */
370 assert(0);
371 break;
372 }
373
374 chan_exts[i].monitor_timer_interval =
375 uchan->monitor_timer_interval;
376 chan_exts[i].blocking_timeout =
377 uchan->attr.u.s.blocking_timeout;
378
379 ret = get_ust_runtime_stats(session, uchan,
380 &discarded_events, &lost_packets);
381 if (ret < 0) {
382 break;
383 }
384 chan_exts[i].discarded_events = discarded_events;
385 chan_exts[i].lost_packets = lost_packets;
386 i++;
387 }
388 rcu_read_unlock();
389 break;
390 }
391 default:
392 break;
393 }
394
395 end:
396 if (ret < 0) {
397 return -LTTNG_ERR_FATAL;
398 } else {
399 return LTTNG_OK;
400 }
401 }
402
403 static int increment_extended_len(const char *filter_expression,
404 struct lttng_event_exclusion *exclusion,
405 const struct lttng_userspace_probe_location *probe_location,
406 size_t *extended_len)
407 {
408 int ret = 0;
409
410 *extended_len += sizeof(struct lttcomm_event_extended_header);
411
412 if (filter_expression) {
413 *extended_len += strlen(filter_expression) + 1;
414 }
415
416 if (exclusion) {
417 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
418 }
419
420 if (probe_location) {
421 ret = lttng_userspace_probe_location_serialize(probe_location,
422 NULL, NULL);
423 if (ret < 0) {
424 goto end;
425 }
426 *extended_len += ret;
427 }
428 ret = 0;
429 end:
430 return ret;
431 }
432
433 static int append_extended_info(const char *filter_expression,
434 struct lttng_event_exclusion *exclusion,
435 struct lttng_userspace_probe_location *probe_location,
436 void **extended_at)
437 {
438 int ret = 0;
439 size_t filter_len = 0;
440 size_t nb_exclusions = 0;
441 size_t userspace_probe_location_len = 0;
442 struct lttng_dynamic_buffer location_buffer;
443 struct lttcomm_event_extended_header extended_header;
444
445 if (filter_expression) {
446 filter_len = strlen(filter_expression) + 1;
447 }
448
449 if (exclusion) {
450 nb_exclusions = exclusion->count;
451 }
452
453 if (probe_location) {
454 lttng_dynamic_buffer_init(&location_buffer);
455 ret = lttng_userspace_probe_location_serialize(probe_location,
456 &location_buffer, NULL);
457 if (ret < 0) {
458 ret = -1;
459 goto end;
460 }
461 userspace_probe_location_len = location_buffer.size;
462 }
463
464 /* Set header fields */
465 extended_header.filter_len = filter_len;
466 extended_header.nb_exclusions = nb_exclusions;
467 extended_header.userspace_probe_location_len = userspace_probe_location_len;
468
469 /* Copy header */
470 memcpy(*extended_at, &extended_header, sizeof(extended_header));
471 *extended_at += sizeof(extended_header);
472
473 /* Copy filter string */
474 if (filter_expression) {
475 memcpy(*extended_at, filter_expression, filter_len);
476 *extended_at += filter_len;
477 }
478
479 /* Copy exclusion names */
480 if (exclusion) {
481 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
482
483 memcpy(*extended_at, &exclusion->names, len);
484 *extended_at += len;
485 }
486
487 if (probe_location) {
488 memcpy(*extended_at, location_buffer.data, location_buffer.size);
489 *extended_at += location_buffer.size;
490 lttng_dynamic_buffer_reset(&location_buffer);
491 }
492 ret = 0;
493 end:
494 return ret;
495 }
496
497 /*
498 * Create a list of agent domain events.
499 *
500 * Return number of events in list on success or else a negative value.
501 */
502 static int list_lttng_agent_events(struct agent *agt,
503 struct lttng_event **events, size_t *total_size)
504 {
505 int i = 0, ret = 0;
506 unsigned int nb_event = 0;
507 struct agent_event *event;
508 struct lttng_event *tmp_events = NULL;
509 struct lttng_ht_iter iter;
510 size_t extended_len = 0;
511 void *extended_at;
512
513 assert(agt);
514 assert(events);
515
516 DBG3("Listing agent events");
517
518 rcu_read_lock();
519 nb_event = lttng_ht_get_count(agt->events);
520 rcu_read_unlock();
521 if (nb_event == 0) {
522 ret = nb_event;
523 *total_size = 0;
524 goto error;
525 }
526
527 /* Compute required extended infos size */
528 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
529
530 /*
531 * This is only valid because the commands which add events are
532 * processed in the same thread as the listing.
533 */
534 rcu_read_lock();
535 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
536 ret = increment_extended_len(event->filter_expression, NULL, NULL,
537 &extended_len);
538 if (ret) {
539 DBG("Error computing the length of extended info message");
540 ret = -LTTNG_ERR_FATAL;
541 goto error;
542 }
543 }
544 rcu_read_unlock();
545
546 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
547 tmp_events = zmalloc(*total_size);
548 if (!tmp_events) {
549 PERROR("zmalloc agent events session");
550 ret = -LTTNG_ERR_FATAL;
551 goto error;
552 }
553
554 extended_at = ((uint8_t *) tmp_events) +
555 nb_event * sizeof(struct lttng_event);
556
557 rcu_read_lock();
558 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
559 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
560 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
561 tmp_events[i].enabled = event->enabled;
562 tmp_events[i].loglevel = event->loglevel_value;
563 tmp_events[i].loglevel_type = event->loglevel_type;
564 i++;
565
566 /* Append extended info */
567 ret = append_extended_info(event->filter_expression, NULL, NULL,
568 &extended_at);
569 if (ret) {
570 DBG("Error appending extended info message");
571 ret = -LTTNG_ERR_FATAL;
572 goto error;
573 }
574 }
575
576 *events = tmp_events;
577 ret = nb_event;
578 assert(nb_event == i);
579
580 end:
581 rcu_read_unlock();
582 return ret;
583 error:
584 free(tmp_events);
585 goto end;
586 }
587
588 /*
589 * Create a list of ust global domain events.
590 */
591 static int list_lttng_ust_global_events(char *channel_name,
592 struct ltt_ust_domain_global *ust_global,
593 struct lttng_event **events, size_t *total_size)
594 {
595 int i = 0, ret = 0;
596 unsigned int nb_event = 0;
597 struct lttng_ht_iter iter;
598 struct lttng_ht_node_str *node;
599 struct ltt_ust_channel *uchan;
600 struct ltt_ust_event *uevent;
601 struct lttng_event *tmp;
602 size_t extended_len = 0;
603 void *extended_at;
604
605 DBG("Listing UST global events for channel %s", channel_name);
606
607 rcu_read_lock();
608
609 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
610 node = lttng_ht_iter_get_node_str(&iter);
611 if (node == NULL) {
612 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
613 goto end;
614 }
615
616 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
617
618 nb_event = lttng_ht_get_count(uchan->events);
619 if (nb_event == 0) {
620 ret = nb_event;
621 *total_size = 0;
622 goto end;
623 }
624
625 DBG3("Listing UST global %d events", nb_event);
626
627 /* Compute required extended infos size */
628 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
629 if (uevent->internal) {
630 nb_event--;
631 continue;
632 }
633
634 ret = increment_extended_len(uevent->filter_expression,
635 uevent->exclusion, NULL, &extended_len);
636 if (ret) {
637 DBG("Error computing the length of extended info message");
638 ret = -LTTNG_ERR_FATAL;
639 goto end;
640 }
641 }
642 if (nb_event == 0) {
643 /* All events are internal, skip. */
644 ret = 0;
645 *total_size = 0;
646 goto end;
647 }
648
649 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
650 tmp = zmalloc(*total_size);
651 if (tmp == NULL) {
652 ret = -LTTNG_ERR_FATAL;
653 goto end;
654 }
655
656 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
657
658 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
659 if (uevent->internal) {
660 /* This event should remain hidden from clients */
661 continue;
662 }
663 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
664 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
665 tmp[i].enabled = uevent->enabled;
666
667 switch (uevent->attr.instrumentation) {
668 case LTTNG_UST_TRACEPOINT:
669 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
670 break;
671 case LTTNG_UST_PROBE:
672 tmp[i].type = LTTNG_EVENT_PROBE;
673 break;
674 case LTTNG_UST_FUNCTION:
675 tmp[i].type = LTTNG_EVENT_FUNCTION;
676 break;
677 }
678
679 tmp[i].loglevel = uevent->attr.loglevel;
680 switch (uevent->attr.loglevel_type) {
681 case LTTNG_UST_LOGLEVEL_ALL:
682 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
683 break;
684 case LTTNG_UST_LOGLEVEL_RANGE:
685 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
686 break;
687 case LTTNG_UST_LOGLEVEL_SINGLE:
688 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
689 break;
690 }
691 if (uevent->filter) {
692 tmp[i].filter = 1;
693 }
694 if (uevent->exclusion) {
695 tmp[i].exclusion = 1;
696 }
697 i++;
698
699 /* Append extended info */
700 ret = append_extended_info(uevent->filter_expression,
701 uevent->exclusion, NULL, &extended_at);
702 if (ret) {
703 DBG("Error appending extended info message");
704 ret = -LTTNG_ERR_FATAL;
705 goto end;
706 }
707 }
708
709 ret = nb_event;
710 *events = tmp;
711 end:
712 rcu_read_unlock();
713 return ret;
714 }
715
716 /*
717 * Fill lttng_event array of all kernel events in the channel.
718 */
719 static int list_lttng_kernel_events(char *channel_name,
720 struct ltt_kernel_session *kernel_session,
721 struct lttng_event **events, size_t *total_size)
722 {
723 int i = 0, ret;
724 unsigned int nb_event;
725 struct ltt_kernel_event *event;
726 struct ltt_kernel_channel *kchan;
727 size_t extended_len = 0;
728 void *extended_at;
729
730 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
731 if (kchan == NULL) {
732 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
733 goto error;
734 }
735
736 nb_event = kchan->event_count;
737
738 DBG("Listing events for channel %s", kchan->channel->name);
739
740 if (nb_event == 0) {
741 *total_size = 0;
742 *events = NULL;
743 goto end;
744 }
745
746 /* Compute required extended infos size */
747 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
748 ret = increment_extended_len(event->filter_expression, NULL,
749 event->userspace_probe_location,
750 &extended_len);
751 if (ret) {
752 DBG("Error computing the length of extended info message");
753 ret = -LTTNG_ERR_FATAL;
754 goto error;
755 }
756 }
757
758 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
759 *events = zmalloc(*total_size);
760 if (*events == NULL) {
761 ret = -LTTNG_ERR_FATAL;
762 goto error;
763 }
764
765 extended_at = ((void *) *events) +
766 nb_event * sizeof(struct lttng_event);
767
768 /* Kernel channels */
769 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
770 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
771 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
772 (*events)[i].enabled = event->enabled;
773 (*events)[i].filter =
774 (unsigned char) !!event->filter_expression;
775
776 switch (event->event->instrumentation) {
777 case LTTNG_KERNEL_TRACEPOINT:
778 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
779 break;
780 case LTTNG_KERNEL_KRETPROBE:
781 (*events)[i].type = LTTNG_EVENT_FUNCTION;
782 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
783 sizeof(struct lttng_kernel_kprobe));
784 break;
785 case LTTNG_KERNEL_KPROBE:
786 (*events)[i].type = LTTNG_EVENT_PROBE;
787 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
788 sizeof(struct lttng_kernel_kprobe));
789 break;
790 case LTTNG_KERNEL_UPROBE:
791 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
792 break;
793 case LTTNG_KERNEL_FUNCTION:
794 (*events)[i].type = LTTNG_EVENT_FUNCTION;
795 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
796 sizeof(struct lttng_kernel_function));
797 break;
798 case LTTNG_KERNEL_NOOP:
799 (*events)[i].type = LTTNG_EVENT_NOOP;
800 break;
801 case LTTNG_KERNEL_SYSCALL:
802 (*events)[i].type = LTTNG_EVENT_SYSCALL;
803 break;
804 case LTTNG_KERNEL_ALL:
805 /* fall-through. */
806 default:
807 assert(0);
808 break;
809 }
810 i++;
811
812 /* Append extended info */
813 ret = append_extended_info(event->filter_expression, NULL,
814 event->userspace_probe_location, &extended_at);
815 if (ret) {
816 DBG("Error appending extended info message");
817 ret = -LTTNG_ERR_FATAL;
818 goto error;
819 }
820 }
821
822 end:
823 return nb_event;
824
825 error:
826 /* Negate the error code to differentiate the size from an error */
827 return -ret;
828 }
829
830 /*
831 * Add URI so the consumer output object. Set the correct path depending on the
832 * domain adding the default trace directory.
833 */
834 static enum lttng_error_code add_uri_to_consumer(
835 const struct ltt_session *session,
836 struct consumer_output *consumer,
837 struct lttng_uri *uri, enum lttng_domain_type domain)
838 {
839 int ret;
840 enum lttng_error_code ret_code = LTTNG_OK;
841
842 assert(uri);
843
844 if (consumer == NULL) {
845 DBG("No consumer detected. Don't add URI. Stopping.");
846 ret_code = LTTNG_ERR_NO_CONSUMER;
847 goto error;
848 }
849
850 switch (domain) {
851 case LTTNG_DOMAIN_KERNEL:
852 ret = lttng_strncpy(consumer->domain_subdir,
853 DEFAULT_KERNEL_TRACE_DIR,
854 sizeof(consumer->domain_subdir));
855 break;
856 case LTTNG_DOMAIN_UST:
857 ret = lttng_strncpy(consumer->domain_subdir,
858 DEFAULT_UST_TRACE_DIR,
859 sizeof(consumer->domain_subdir));
860 break;
861 default:
862 /*
863 * This case is possible is we try to add the URI to the global
864 * tracing session consumer object which in this case there is
865 * no subdir.
866 */
867 memset(consumer->domain_subdir, 0,
868 sizeof(consumer->domain_subdir));
869 ret = 0;
870 }
871 if (ret) {
872 ERR("Failed to initialize consumer output domain subdirectory");
873 ret_code = LTTNG_ERR_FATAL;
874 goto error;
875 }
876
877 switch (uri->dtype) {
878 case LTTNG_DST_IPV4:
879 case LTTNG_DST_IPV6:
880 DBG2("Setting network URI to consumer");
881
882 if (consumer->type == CONSUMER_DST_NET) {
883 if ((uri->stype == LTTNG_STREAM_CONTROL &&
884 consumer->dst.net.control_isset) ||
885 (uri->stype == LTTNG_STREAM_DATA &&
886 consumer->dst.net.data_isset)) {
887 ret_code = LTTNG_ERR_URL_EXIST;
888 goto error;
889 }
890 } else {
891 memset(&consumer->dst, 0, sizeof(consumer->dst));
892 }
893
894 /* Set URI into consumer output object */
895 ret = consumer_set_network_uri(session, consumer, uri);
896 if (ret < 0) {
897 ret_code = -ret;
898 goto error;
899 } else if (ret == 1) {
900 /*
901 * URI was the same in the consumer so we do not append the subdir
902 * again so to not duplicate output dir.
903 */
904 ret_code = LTTNG_OK;
905 goto error;
906 }
907 break;
908 case LTTNG_DST_PATH:
909 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
910 ret_code = LTTNG_ERR_INVALID;
911 goto error;
912 }
913 DBG2("Setting trace directory path from URI to %s",
914 uri->dst.path);
915 memset(&consumer->dst, 0, sizeof(consumer->dst));
916
917 ret = lttng_strncpy(consumer->dst.session_root_path,
918 uri->dst.path,
919 sizeof(consumer->dst.session_root_path));
920 if (ret) {
921 ret_code = LTTNG_ERR_FATAL;
922 goto error;
923 }
924 consumer->type = CONSUMER_DST_LOCAL;
925 break;
926 }
927
928 ret_code = LTTNG_OK;
929 error:
930 return ret_code;
931 }
932
933 /*
934 * Init tracing by creating trace directory and sending fds kernel consumer.
935 */
936 static int init_kernel_tracing(struct ltt_kernel_session *session)
937 {
938 int ret = 0;
939 struct lttng_ht_iter iter;
940 struct consumer_socket *socket;
941
942 assert(session);
943
944 rcu_read_lock();
945
946 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
947 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
948 socket, node.node) {
949 pthread_mutex_lock(socket->lock);
950 ret = kernel_consumer_send_session(socket, session);
951 pthread_mutex_unlock(socket->lock);
952 if (ret < 0) {
953 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
954 goto error;
955 }
956 }
957 }
958
959 error:
960 rcu_read_unlock();
961 return ret;
962 }
963
964 /*
965 * Create a socket to the relayd using the URI.
966 *
967 * On success, the relayd_sock pointer is set to the created socket.
968 * Else, it remains untouched and an LTTng error code is returned.
969 */
970 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
971 struct lttcomm_relayd_sock **relayd_sock,
972 struct consumer_output *consumer)
973 {
974 int ret;
975 enum lttng_error_code status = LTTNG_OK;
976 struct lttcomm_relayd_sock *rsock;
977
978 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
979 RELAYD_VERSION_COMM_MINOR);
980 if (!rsock) {
981 status = LTTNG_ERR_FATAL;
982 goto error;
983 }
984
985 /*
986 * Connect to relayd so we can proceed with a session creation. This call
987 * can possibly block for an arbitrary amount of time to set the health
988 * state to be in poll execution.
989 */
990 health_poll_entry();
991 ret = relayd_connect(rsock);
992 health_poll_exit();
993 if (ret < 0) {
994 ERR("Unable to reach lttng-relayd");
995 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
996 goto free_sock;
997 }
998
999 /* Create socket for control stream. */
1000 if (uri->stype == LTTNG_STREAM_CONTROL) {
1001 DBG3("Creating relayd stream socket from URI");
1002
1003 /* Check relayd version */
1004 ret = relayd_version_check(rsock);
1005 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
1006 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
1007 goto close_sock;
1008 } else if (ret < 0) {
1009 ERR("Unable to reach lttng-relayd");
1010 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1011 goto close_sock;
1012 }
1013 consumer->relay_major_version = rsock->major;
1014 consumer->relay_minor_version = rsock->minor;
1015 } else if (uri->stype == LTTNG_STREAM_DATA) {
1016 DBG3("Creating relayd data socket from URI");
1017 } else {
1018 /* Command is not valid */
1019 ERR("Relayd invalid stream type: %d", uri->stype);
1020 status = LTTNG_ERR_INVALID;
1021 goto close_sock;
1022 }
1023
1024 *relayd_sock = rsock;
1025
1026 return status;
1027
1028 close_sock:
1029 /* The returned value is not useful since we are on an error path. */
1030 (void) relayd_close(rsock);
1031 free_sock:
1032 free(rsock);
1033 error:
1034 return status;
1035 }
1036
1037 /*
1038 * Connect to the relayd using URI and send the socket to the right consumer.
1039 *
1040 * The consumer socket lock must be held by the caller.
1041 *
1042 * Returns LTTNG_OK on success or an LTTng error code on failure.
1043 */
1044 static enum lttng_error_code send_consumer_relayd_socket(
1045 unsigned int session_id,
1046 struct lttng_uri *relayd_uri,
1047 struct consumer_output *consumer,
1048 struct consumer_socket *consumer_sock,
1049 const char *session_name, const char *hostname,
1050 const char *base_path, int session_live_timer,
1051 const uint64_t *current_chunk_id,
1052 time_t session_creation_time,
1053 bool session_name_contains_creation_time)
1054 {
1055 int ret;
1056 struct lttcomm_relayd_sock *rsock = NULL;
1057 enum lttng_error_code status;
1058
1059 /* Connect to relayd and make version check if uri is the control. */
1060 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1061 if (status != LTTNG_OK) {
1062 goto relayd_comm_error;
1063 }
1064 assert(rsock);
1065
1066 /* Set the network sequence index if not set. */
1067 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1068 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1069 /*
1070 * Increment net_seq_idx because we are about to transfer the
1071 * new relayd socket to the consumer.
1072 * Assign unique key so the consumer can match streams.
1073 */
1074 consumer->net_seq_index = ++relayd_net_seq_idx;
1075 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1076 }
1077
1078 /* Send relayd socket to consumer. */
1079 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1080 relayd_uri->stype, session_id,
1081 session_name, hostname, base_path,
1082 session_live_timer, current_chunk_id,
1083 session_creation_time, session_name_contains_creation_time);
1084 if (ret < 0) {
1085 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1086 goto close_sock;
1087 }
1088
1089 /* Flag that the corresponding socket was sent. */
1090 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1091 consumer_sock->control_sock_sent = 1;
1092 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1093 consumer_sock->data_sock_sent = 1;
1094 }
1095
1096 /*
1097 * Close socket which was dup on the consumer side. The session daemon does
1098 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1099 */
1100
1101 close_sock:
1102 if (status != LTTNG_OK) {
1103 /*
1104 * The consumer output for this session should not be used anymore
1105 * since the relayd connection failed thus making any tracing or/and
1106 * streaming not usable.
1107 */
1108 consumer->enabled = 0;
1109 }
1110 (void) relayd_close(rsock);
1111 free(rsock);
1112
1113 relayd_comm_error:
1114 return status;
1115 }
1116
1117 /*
1118 * Send both relayd sockets to a specific consumer and domain. This is a
1119 * helper function to facilitate sending the information to the consumer for a
1120 * session.
1121 *
1122 * The consumer socket lock must be held by the caller.
1123 *
1124 * Returns LTTNG_OK, or an LTTng error code on failure.
1125 */
1126 static enum lttng_error_code send_consumer_relayd_sockets(
1127 enum lttng_domain_type domain,
1128 unsigned int session_id, struct consumer_output *consumer,
1129 struct consumer_socket *sock, const char *session_name,
1130 const char *hostname, const char *base_path, int session_live_timer,
1131 const uint64_t *current_chunk_id, time_t session_creation_time,
1132 bool session_name_contains_creation_time)
1133 {
1134 enum lttng_error_code status = LTTNG_OK;
1135
1136 assert(consumer);
1137 assert(sock);
1138
1139 /* Sending control relayd socket. */
1140 if (!sock->control_sock_sent) {
1141 status = send_consumer_relayd_socket(session_id,
1142 &consumer->dst.net.control, consumer, sock,
1143 session_name, hostname, base_path, session_live_timer,
1144 current_chunk_id, session_creation_time,
1145 session_name_contains_creation_time);
1146 if (status != LTTNG_OK) {
1147 goto error;
1148 }
1149 }
1150
1151 /* Sending data relayd socket. */
1152 if (!sock->data_sock_sent) {
1153 status = send_consumer_relayd_socket(session_id,
1154 &consumer->dst.net.data, consumer, sock,
1155 session_name, hostname, base_path, session_live_timer,
1156 current_chunk_id, session_creation_time,
1157 session_name_contains_creation_time);
1158 if (status != LTTNG_OK) {
1159 goto error;
1160 }
1161 }
1162
1163 error:
1164 return status;
1165 }
1166
1167 /*
1168 * Setup relayd connections for a tracing session. First creates the socket to
1169 * the relayd and send them to the right domain consumer. Consumer type MUST be
1170 * network.
1171 */
1172 int cmd_setup_relayd(struct ltt_session *session)
1173 {
1174 int ret = LTTNG_OK;
1175 struct ltt_ust_session *usess;
1176 struct ltt_kernel_session *ksess;
1177 struct consumer_socket *socket;
1178 struct lttng_ht_iter iter;
1179 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1180
1181 assert(session);
1182
1183 usess = session->ust_session;
1184 ksess = session->kernel_session;
1185
1186 DBG("Setting relayd for session %s", session->name);
1187
1188 rcu_read_lock();
1189 if (session->current_trace_chunk) {
1190 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1191 session->current_trace_chunk, &current_chunk_id.value);
1192
1193 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1194 current_chunk_id.is_set = true;
1195 } else {
1196 ERR("Failed to get current trace chunk id");
1197 ret = LTTNG_ERR_UNK;
1198 goto error;
1199 }
1200 }
1201
1202 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1203 && usess->consumer->enabled) {
1204 /* For each consumer socket, send relayd sockets */
1205 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1206 socket, node.node) {
1207 pthread_mutex_lock(socket->lock);
1208 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1209 usess->consumer, socket,
1210 session->name, session->hostname,
1211 session->base_path,
1212 session->live_timer,
1213 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1214 session->creation_time,
1215 session->name_contains_creation_time);
1216 pthread_mutex_unlock(socket->lock);
1217 if (ret != LTTNG_OK) {
1218 goto error;
1219 }
1220 /* Session is now ready for network streaming. */
1221 session->net_handle = 1;
1222 }
1223 session->consumer->relay_major_version =
1224 usess->consumer->relay_major_version;
1225 session->consumer->relay_minor_version =
1226 usess->consumer->relay_minor_version;
1227 }
1228
1229 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1230 && ksess->consumer->enabled) {
1231 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1232 socket, node.node) {
1233 pthread_mutex_lock(socket->lock);
1234 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1235 ksess->consumer, socket,
1236 session->name, session->hostname,
1237 session->base_path,
1238 session->live_timer,
1239 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1240 session->creation_time,
1241 session->name_contains_creation_time);
1242 pthread_mutex_unlock(socket->lock);
1243 if (ret != LTTNG_OK) {
1244 goto error;
1245 }
1246 /* Session is now ready for network streaming. */
1247 session->net_handle = 1;
1248 }
1249 session->consumer->relay_major_version =
1250 ksess->consumer->relay_major_version;
1251 session->consumer->relay_minor_version =
1252 ksess->consumer->relay_minor_version;
1253 }
1254
1255 error:
1256 rcu_read_unlock();
1257 return ret;
1258 }
1259
1260 /*
1261 * Start a kernel session by opening all necessary streams.
1262 */
1263 int start_kernel_session(struct ltt_kernel_session *ksess)
1264 {
1265 int ret;
1266 struct ltt_kernel_channel *kchan;
1267
1268 /* Open kernel metadata */
1269 if (ksess->metadata == NULL && ksess->output_traces) {
1270 ret = kernel_open_metadata(ksess);
1271 if (ret < 0) {
1272 ret = LTTNG_ERR_KERN_META_FAIL;
1273 goto error;
1274 }
1275 }
1276
1277 /* Open kernel metadata stream */
1278 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1279 ret = kernel_open_metadata_stream(ksess);
1280 if (ret < 0) {
1281 ERR("Kernel create metadata stream failed");
1282 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1283 goto error;
1284 }
1285 }
1286
1287 /* For each channel */
1288 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1289 if (kchan->stream_count == 0) {
1290 ret = kernel_open_channel_stream(kchan);
1291 if (ret < 0) {
1292 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1293 goto error;
1294 }
1295 /* Update the stream global counter */
1296 ksess->stream_count_global += ret;
1297 }
1298 }
1299
1300 /* Setup kernel consumer socket and send fds to it */
1301 ret = init_kernel_tracing(ksess);
1302 if (ret != 0) {
1303 ret = LTTNG_ERR_KERN_START_FAIL;
1304 goto error;
1305 }
1306
1307 /* This start the kernel tracing */
1308 ret = kernel_start_session(ksess);
1309 if (ret < 0) {
1310 ret = LTTNG_ERR_KERN_START_FAIL;
1311 goto error;
1312 }
1313
1314 /* Quiescent wait after starting trace */
1315 kernel_wait_quiescent();
1316
1317 ksess->active = 1;
1318
1319 ret = LTTNG_OK;
1320
1321 error:
1322 return ret;
1323 }
1324
1325 int stop_kernel_session(struct ltt_kernel_session *ksess)
1326 {
1327 struct ltt_kernel_channel *kchan;
1328 bool error_occurred = false;
1329 int ret;
1330
1331 if (!ksess || !ksess->active) {
1332 return LTTNG_OK;
1333 }
1334 DBG("Stopping kernel tracing");
1335
1336 ret = kernel_stop_session(ksess);
1337 if (ret < 0) {
1338 ret = LTTNG_ERR_KERN_STOP_FAIL;
1339 goto error;
1340 }
1341
1342 kernel_wait_quiescent();
1343
1344 /* Flush metadata after stopping (if exists) */
1345 if (ksess->metadata_stream_fd >= 0) {
1346 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1347 if (ret < 0) {
1348 ERR("Kernel metadata flush failed");
1349 error_occurred = true;
1350 }
1351 }
1352
1353 /* Flush all buffers after stopping */
1354 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1355 ret = kernel_flush_buffer(kchan);
1356 if (ret < 0) {
1357 ERR("Kernel flush buffer error");
1358 error_occurred = true;
1359 }
1360 }
1361
1362 ksess->active = 0;
1363 if (error_occurred) {
1364 ret = LTTNG_ERR_UNK;
1365 } else {
1366 ret = LTTNG_OK;
1367 }
1368 error:
1369 return ret;
1370 }
1371
1372 /*
1373 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1374 */
1375 int cmd_disable_channel(struct ltt_session *session,
1376 enum lttng_domain_type domain, char *channel_name)
1377 {
1378 int ret;
1379 struct ltt_ust_session *usess;
1380
1381 usess = session->ust_session;
1382
1383 rcu_read_lock();
1384
1385 switch (domain) {
1386 case LTTNG_DOMAIN_KERNEL:
1387 {
1388 ret = channel_kernel_disable(session->kernel_session,
1389 channel_name);
1390 if (ret != LTTNG_OK) {
1391 goto error;
1392 }
1393
1394 kernel_wait_quiescent();
1395 break;
1396 }
1397 case LTTNG_DOMAIN_UST:
1398 {
1399 struct ltt_ust_channel *uchan;
1400 struct lttng_ht *chan_ht;
1401
1402 chan_ht = usess->domain_global.channels;
1403
1404 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1405 if (uchan == NULL) {
1406 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1407 goto error;
1408 }
1409
1410 ret = channel_ust_disable(usess, uchan);
1411 if (ret != LTTNG_OK) {
1412 goto error;
1413 }
1414 break;
1415 }
1416 default:
1417 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1418 goto error;
1419 }
1420
1421 ret = LTTNG_OK;
1422
1423 error:
1424 rcu_read_unlock();
1425 return ret;
1426 }
1427
1428 /*
1429 * Command LTTNG_TRACK_PID processed by the client thread.
1430 *
1431 * Called with session lock held.
1432 */
1433 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1434 int pid)
1435 {
1436 int ret;
1437
1438 rcu_read_lock();
1439
1440 switch (domain) {
1441 case LTTNG_DOMAIN_KERNEL:
1442 {
1443 struct ltt_kernel_session *ksess;
1444
1445 ksess = session->kernel_session;
1446
1447 ret = kernel_track_pid(ksess, pid);
1448 if (ret != LTTNG_OK) {
1449 goto error;
1450 }
1451
1452 kernel_wait_quiescent();
1453 break;
1454 }
1455 case LTTNG_DOMAIN_UST:
1456 {
1457 struct ltt_ust_session *usess;
1458
1459 usess = session->ust_session;
1460
1461 ret = trace_ust_track_pid(usess, pid);
1462 if (ret != LTTNG_OK) {
1463 goto error;
1464 }
1465 break;
1466 }
1467 default:
1468 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1469 goto error;
1470 }
1471
1472 ret = LTTNG_OK;
1473
1474 error:
1475 rcu_read_unlock();
1476 return ret;
1477 }
1478
1479 /*
1480 * Command LTTNG_UNTRACK_PID processed by the client thread.
1481 *
1482 * Called with session lock held.
1483 */
1484 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1485 int pid)
1486 {
1487 int ret;
1488
1489 rcu_read_lock();
1490
1491 switch (domain) {
1492 case LTTNG_DOMAIN_KERNEL:
1493 {
1494 struct ltt_kernel_session *ksess;
1495
1496 ksess = session->kernel_session;
1497
1498 ret = kernel_untrack_pid(ksess, pid);
1499 if (ret != LTTNG_OK) {
1500 goto error;
1501 }
1502
1503 kernel_wait_quiescent();
1504 break;
1505 }
1506 case LTTNG_DOMAIN_UST:
1507 {
1508 struct ltt_ust_session *usess;
1509
1510 usess = session->ust_session;
1511
1512 ret = trace_ust_untrack_pid(usess, pid);
1513 if (ret != LTTNG_OK) {
1514 goto error;
1515 }
1516 break;
1517 }
1518 default:
1519 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1520 goto error;
1521 }
1522
1523 ret = LTTNG_OK;
1524
1525 error:
1526 rcu_read_unlock();
1527 return ret;
1528 }
1529
1530 /*
1531 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1532 *
1533 * The wpipe arguments is used as a notifier for the kernel thread.
1534 */
1535 int cmd_enable_channel(struct ltt_session *session,
1536 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1537 {
1538 int ret;
1539 struct ltt_ust_session *usess = session->ust_session;
1540 struct lttng_ht *chan_ht;
1541 size_t len;
1542 struct lttng_channel attr;
1543
1544 assert(session);
1545 assert(_attr);
1546 assert(domain);
1547
1548 attr = *_attr;
1549 len = lttng_strnlen(attr.name, sizeof(attr.name));
1550
1551 /* Validate channel name */
1552 if (attr.name[0] == '.' ||
1553 memchr(attr.name, '/', len) != NULL) {
1554 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1555 goto end;
1556 }
1557
1558 DBG("Enabling channel %s for session %s", attr.name, session->name);
1559
1560 rcu_read_lock();
1561
1562 /*
1563 * Don't try to enable a channel if the session has been started at
1564 * some point in time before. The tracer does not allow it.
1565 */
1566 if (session->has_been_started) {
1567 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1568 goto error;
1569 }
1570
1571 /*
1572 * If the session is a live session, remove the switch timer, the
1573 * live timer does the same thing but sends also synchronisation
1574 * beacons for inactive streams.
1575 */
1576 if (session->live_timer > 0) {
1577 attr.attr.live_timer_interval = session->live_timer;
1578 attr.attr.switch_timer_interval = 0;
1579 }
1580
1581 /* Check for feature support */
1582 switch (domain->type) {
1583 case LTTNG_DOMAIN_KERNEL:
1584 {
1585 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1586 /* Sampling position of buffer is not supported */
1587 WARN("Kernel tracer does not support buffer monitoring. "
1588 "Setting the monitor interval timer to 0 "
1589 "(disabled) for channel '%s' of session '%s'",
1590 attr.name, session->name);
1591 lttng_channel_set_monitor_timer_interval(&attr, 0);
1592 }
1593 break;
1594 }
1595 case LTTNG_DOMAIN_UST:
1596 break;
1597 case LTTNG_DOMAIN_JUL:
1598 case LTTNG_DOMAIN_LOG4J:
1599 case LTTNG_DOMAIN_PYTHON:
1600 if (!agent_tracing_is_enabled()) {
1601 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1602 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1603 goto error;
1604 }
1605 break;
1606 default:
1607 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1608 goto error;
1609 }
1610
1611 switch (domain->type) {
1612 case LTTNG_DOMAIN_KERNEL:
1613 {
1614 struct ltt_kernel_channel *kchan;
1615
1616 kchan = trace_kernel_get_channel_by_name(attr.name,
1617 session->kernel_session);
1618 if (kchan == NULL) {
1619 if (session->snapshot.nb_output > 0 ||
1620 session->snapshot_mode) {
1621 /* Enforce mmap output for snapshot sessions. */
1622 attr.attr.output = LTTNG_EVENT_MMAP;
1623 }
1624 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1625 if (attr.name[0] != '\0') {
1626 session->kernel_session->has_non_default_channel = 1;
1627 }
1628 } else {
1629 ret = channel_kernel_enable(session->kernel_session, kchan);
1630 }
1631
1632 if (ret != LTTNG_OK) {
1633 goto error;
1634 }
1635
1636 kernel_wait_quiescent();
1637 break;
1638 }
1639 case LTTNG_DOMAIN_UST:
1640 case LTTNG_DOMAIN_JUL:
1641 case LTTNG_DOMAIN_LOG4J:
1642 case LTTNG_DOMAIN_PYTHON:
1643 {
1644 struct ltt_ust_channel *uchan;
1645
1646 /*
1647 * FIXME
1648 *
1649 * Current agent implementation limitations force us to allow
1650 * only one channel at once in "agent" subdomains. Each
1651 * subdomain has a default channel name which must be strictly
1652 * adhered to.
1653 */
1654 if (domain->type == LTTNG_DOMAIN_JUL) {
1655 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1656 LTTNG_SYMBOL_NAME_LEN)) {
1657 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1658 goto error;
1659 }
1660 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1661 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1662 LTTNG_SYMBOL_NAME_LEN)) {
1663 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1664 goto error;
1665 }
1666 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1667 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1668 LTTNG_SYMBOL_NAME_LEN)) {
1669 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1670 goto error;
1671 }
1672 }
1673
1674 chan_ht = usess->domain_global.channels;
1675
1676 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1677 if (uchan == NULL) {
1678 ret = channel_ust_create(usess, &attr, domain->buf_type);
1679 if (attr.name[0] != '\0') {
1680 usess->has_non_default_channel = 1;
1681 }
1682 } else {
1683 ret = channel_ust_enable(usess, uchan);
1684 }
1685 break;
1686 }
1687 default:
1688 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1689 goto error;
1690 }
1691
1692 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1693 session->has_non_mmap_channel = true;
1694 }
1695 error:
1696 rcu_read_unlock();
1697 end:
1698 return ret;
1699 }
1700
1701 /*
1702 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1703 */
1704 int cmd_disable_event(struct ltt_session *session,
1705 enum lttng_domain_type domain, const char *channel_name,
1706 const struct lttng_event *event)
1707 {
1708 int ret;
1709 const char *event_name;
1710
1711 DBG("Disable event command for event \'%s\'", event->name);
1712
1713 event_name = event->name;
1714
1715 /* Error out on unhandled search criteria */
1716 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1717 || event->pid || event->filter || event->exclusion) {
1718 ret = LTTNG_ERR_UNK;
1719 goto error;
1720 }
1721
1722 rcu_read_lock();
1723
1724 switch (domain) {
1725 case LTTNG_DOMAIN_KERNEL:
1726 {
1727 struct ltt_kernel_channel *kchan;
1728 struct ltt_kernel_session *ksess;
1729
1730 ksess = session->kernel_session;
1731
1732 /*
1733 * If a non-default channel has been created in the
1734 * session, explicitely require that -c chan_name needs
1735 * to be provided.
1736 */
1737 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1738 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1739 goto error_unlock;
1740 }
1741
1742 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1743 if (kchan == NULL) {
1744 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1745 goto error_unlock;
1746 }
1747
1748 switch (event->type) {
1749 case LTTNG_EVENT_ALL:
1750 case LTTNG_EVENT_TRACEPOINT:
1751 case LTTNG_EVENT_SYSCALL:
1752 case LTTNG_EVENT_PROBE:
1753 case LTTNG_EVENT_FUNCTION:
1754 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1755 if (event_name[0] == '\0') {
1756 ret = event_kernel_disable_event(kchan,
1757 NULL, event->type);
1758 } else {
1759 ret = event_kernel_disable_event(kchan,
1760 event_name, event->type);
1761 }
1762 if (ret != LTTNG_OK) {
1763 goto error_unlock;
1764 }
1765 break;
1766 default:
1767 ret = LTTNG_ERR_UNK;
1768 goto error_unlock;
1769 }
1770
1771 kernel_wait_quiescent();
1772 break;
1773 }
1774 case LTTNG_DOMAIN_UST:
1775 {
1776 struct ltt_ust_channel *uchan;
1777 struct ltt_ust_session *usess;
1778
1779 usess = session->ust_session;
1780
1781 if (validate_ust_event_name(event_name)) {
1782 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1783 goto error_unlock;
1784 }
1785
1786 /*
1787 * If a non-default channel has been created in the
1788 * session, explicitly require that -c chan_name needs
1789 * to be provided.
1790 */
1791 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1792 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1793 goto error_unlock;
1794 }
1795
1796 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1797 channel_name);
1798 if (uchan == NULL) {
1799 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1800 goto error_unlock;
1801 }
1802
1803 switch (event->type) {
1804 case LTTNG_EVENT_ALL:
1805 /*
1806 * An empty event name means that everything
1807 * should be disabled.
1808 */
1809 if (event->name[0] == '\0') {
1810 ret = event_ust_disable_all_tracepoints(usess, uchan);
1811 } else {
1812 ret = event_ust_disable_tracepoint(usess, uchan,
1813 event_name);
1814 }
1815 if (ret != LTTNG_OK) {
1816 goto error_unlock;
1817 }
1818 break;
1819 default:
1820 ret = LTTNG_ERR_UNK;
1821 goto error_unlock;
1822 }
1823
1824 DBG3("Disable UST event %s in channel %s completed", event_name,
1825 channel_name);
1826 break;
1827 }
1828 case LTTNG_DOMAIN_LOG4J:
1829 case LTTNG_DOMAIN_JUL:
1830 case LTTNG_DOMAIN_PYTHON:
1831 {
1832 struct agent *agt;
1833 struct ltt_ust_session *usess = session->ust_session;
1834
1835 assert(usess);
1836
1837 switch (event->type) {
1838 case LTTNG_EVENT_ALL:
1839 break;
1840 default:
1841 ret = LTTNG_ERR_UNK;
1842 goto error_unlock;
1843 }
1844
1845 agt = trace_ust_find_agent(usess, domain);
1846 if (!agt) {
1847 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1848 goto error_unlock;
1849 }
1850 /*
1851 * An empty event name means that everything
1852 * should be disabled.
1853 */
1854 if (event->name[0] == '\0') {
1855 ret = event_agent_disable_all(usess, agt);
1856 } else {
1857 ret = event_agent_disable(usess, agt, event_name);
1858 }
1859 if (ret != LTTNG_OK) {
1860 goto error_unlock;
1861 }
1862
1863 break;
1864 }
1865 default:
1866 ret = LTTNG_ERR_UND;
1867 goto error_unlock;
1868 }
1869
1870 ret = LTTNG_OK;
1871
1872 error_unlock:
1873 rcu_read_unlock();
1874 error:
1875 return ret;
1876 }
1877
1878 /*
1879 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1880 */
1881 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1882 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1883 {
1884 int ret, chan_kern_created = 0, chan_ust_created = 0;
1885 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1886
1887 /*
1888 * Don't try to add a context if the session has been started at
1889 * some point in time before. The tracer does not allow it and would
1890 * result in a corrupted trace.
1891 */
1892 if (session->has_been_started) {
1893 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1894 goto end;
1895 }
1896
1897 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1898 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1899 app_ctx_name = ctx->u.app_ctx.ctx_name;
1900 }
1901
1902 switch (domain) {
1903 case LTTNG_DOMAIN_KERNEL:
1904 assert(session->kernel_session);
1905
1906 if (session->kernel_session->channel_count == 0) {
1907 /* Create default channel */
1908 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1909 if (ret != LTTNG_OK) {
1910 goto error;
1911 }
1912 chan_kern_created = 1;
1913 }
1914 /* Add kernel context to kernel tracer */
1915 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1916 if (ret != LTTNG_OK) {
1917 goto error;
1918 }
1919 break;
1920 case LTTNG_DOMAIN_JUL:
1921 case LTTNG_DOMAIN_LOG4J:
1922 {
1923 /*
1924 * Validate channel name.
1925 * If no channel name is given and the domain is JUL or LOG4J,
1926 * set it to the appropriate domain-specific channel name. If
1927 * a name is provided but does not match the expexted channel
1928 * name, return an error.
1929 */
1930 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1931 strcmp(channel_name,
1932 DEFAULT_JUL_CHANNEL_NAME)) {
1933 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1934 goto error;
1935 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1936 strcmp(channel_name,
1937 DEFAULT_LOG4J_CHANNEL_NAME)) {
1938 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1939 goto error;
1940 }
1941 /* break is _not_ missing here. */
1942 }
1943 case LTTNG_DOMAIN_UST:
1944 {
1945 struct ltt_ust_session *usess = session->ust_session;
1946 unsigned int chan_count;
1947
1948 assert(usess);
1949
1950 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1951 if (chan_count == 0) {
1952 struct lttng_channel *attr;
1953 /* Create default channel */
1954 attr = channel_new_default_attr(domain, usess->buffer_type);
1955 if (attr == NULL) {
1956 ret = LTTNG_ERR_FATAL;
1957 goto error;
1958 }
1959
1960 ret = channel_ust_create(usess, attr, usess->buffer_type);
1961 if (ret != LTTNG_OK) {
1962 free(attr);
1963 goto error;
1964 }
1965 channel_attr_destroy(attr);
1966 chan_ust_created = 1;
1967 }
1968
1969 ret = context_ust_add(usess, domain, ctx, channel_name);
1970 free(app_ctx_provider_name);
1971 free(app_ctx_name);
1972 app_ctx_name = NULL;
1973 app_ctx_provider_name = NULL;
1974 if (ret != LTTNG_OK) {
1975 goto error;
1976 }
1977 break;
1978 }
1979 default:
1980 ret = LTTNG_ERR_UND;
1981 goto error;
1982 }
1983
1984 ret = LTTNG_OK;
1985 goto end;
1986
1987 error:
1988 if (chan_kern_created) {
1989 struct ltt_kernel_channel *kchan =
1990 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1991 session->kernel_session);
1992 /* Created previously, this should NOT fail. */
1993 assert(kchan);
1994 kernel_destroy_channel(kchan);
1995 }
1996
1997 if (chan_ust_created) {
1998 struct ltt_ust_channel *uchan =
1999 trace_ust_find_channel_by_name(
2000 session->ust_session->domain_global.channels,
2001 DEFAULT_CHANNEL_NAME);
2002 /* Created previously, this should NOT fail. */
2003 assert(uchan);
2004 /* Remove from the channel list of the session. */
2005 trace_ust_delete_channel(session->ust_session->domain_global.channels,
2006 uchan);
2007 trace_ust_destroy_channel(uchan);
2008 }
2009 end:
2010 free(app_ctx_provider_name);
2011 free(app_ctx_name);
2012 return ret;
2013 }
2014
2015 static inline bool name_starts_with(const char *name, const char *prefix)
2016 {
2017 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
2018
2019 return !strncmp(name, prefix, max_cmp_len);
2020 }
2021
2022 /* Perform userspace-specific event name validation */
2023 static int validate_ust_event_name(const char *name)
2024 {
2025 int ret = 0;
2026
2027 if (!name) {
2028 ret = -1;
2029 goto end;
2030 }
2031
2032 /*
2033 * Check name against all internal UST event component namespaces used
2034 * by the agents.
2035 */
2036 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2037 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2038 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2039 ret = -1;
2040 }
2041
2042 end:
2043 return ret;
2044 }
2045
2046 /*
2047 * Internal version of cmd_enable_event() with a supplemental
2048 * "internal_event" flag which is used to enable internal events which should
2049 * be hidden from clients. Such events are used in the agent implementation to
2050 * enable the events through which all "agent" events are funeled.
2051 */
2052 static int _cmd_enable_event(struct ltt_session *session,
2053 const struct lttng_domain *domain,
2054 char *channel_name, struct lttng_event *event,
2055 char *filter_expression,
2056 struct lttng_filter_bytecode *filter,
2057 struct lttng_event_exclusion *exclusion,
2058 int wpipe, bool internal_event)
2059 {
2060 int ret = 0, channel_created = 0;
2061 struct lttng_channel *attr = NULL;
2062
2063 assert(session);
2064 assert(event);
2065 assert(channel_name);
2066
2067 /* If we have a filter, we must have its filter expression */
2068 assert(!(!!filter_expression ^ !!filter));
2069
2070 /* Normalize event name as a globbing pattern */
2071 strutils_normalize_star_glob_pattern(event->name);
2072
2073 /* Normalize exclusion names as globbing patterns */
2074 if (exclusion) {
2075 size_t i;
2076
2077 for (i = 0; i < exclusion->count; i++) {
2078 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2079
2080 strutils_normalize_star_glob_pattern(name);
2081 }
2082 }
2083
2084 DBG("Enable event command for event \'%s\'", event->name);
2085
2086 rcu_read_lock();
2087
2088 switch (domain->type) {
2089 case LTTNG_DOMAIN_KERNEL:
2090 {
2091 struct ltt_kernel_channel *kchan;
2092
2093 /*
2094 * If a non-default channel has been created in the
2095 * session, explicitely require that -c chan_name needs
2096 * to be provided.
2097 */
2098 if (session->kernel_session->has_non_default_channel
2099 && channel_name[0] == '\0') {
2100 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2101 goto error;
2102 }
2103
2104 kchan = trace_kernel_get_channel_by_name(channel_name,
2105 session->kernel_session);
2106 if (kchan == NULL) {
2107 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2108 LTTNG_BUFFER_GLOBAL);
2109 if (attr == NULL) {
2110 ret = LTTNG_ERR_FATAL;
2111 goto error;
2112 }
2113 if (lttng_strncpy(attr->name, channel_name,
2114 sizeof(attr->name))) {
2115 ret = LTTNG_ERR_INVALID;
2116 goto error;
2117 }
2118
2119 ret = cmd_enable_channel(session, domain, attr, wpipe);
2120 if (ret != LTTNG_OK) {
2121 goto error;
2122 }
2123 channel_created = 1;
2124 }
2125
2126 /* Get the newly created kernel channel pointer */
2127 kchan = trace_kernel_get_channel_by_name(channel_name,
2128 session->kernel_session);
2129 if (kchan == NULL) {
2130 /* This sould not happen... */
2131 ret = LTTNG_ERR_FATAL;
2132 goto error;
2133 }
2134
2135 switch (event->type) {
2136 case LTTNG_EVENT_ALL:
2137 {
2138 char *filter_expression_a = NULL;
2139 struct lttng_filter_bytecode *filter_a = NULL;
2140
2141 /*
2142 * We need to duplicate filter_expression and filter,
2143 * because ownership is passed to first enable
2144 * event.
2145 */
2146 if (filter_expression) {
2147 filter_expression_a = strdup(filter_expression);
2148 if (!filter_expression_a) {
2149 ret = LTTNG_ERR_FATAL;
2150 goto error;
2151 }
2152 }
2153 if (filter) {
2154 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2155 if (!filter_a) {
2156 free(filter_expression_a);
2157 ret = LTTNG_ERR_FATAL;
2158 goto error;
2159 }
2160 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2161 }
2162 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2163 ret = event_kernel_enable_event(kchan, event,
2164 filter_expression, filter);
2165 /* We have passed ownership */
2166 filter_expression = NULL;
2167 filter = NULL;
2168 if (ret != LTTNG_OK) {
2169 if (channel_created) {
2170 /* Let's not leak a useless channel. */
2171 kernel_destroy_channel(kchan);
2172 }
2173 free(filter_expression_a);
2174 free(filter_a);
2175 goto error;
2176 }
2177 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2178 ret = event_kernel_enable_event(kchan, event,
2179 filter_expression_a, filter_a);
2180 /* We have passed ownership */
2181 filter_expression_a = NULL;
2182 filter_a = NULL;
2183 if (ret != LTTNG_OK) {
2184 goto error;
2185 }
2186 break;
2187 }
2188 case LTTNG_EVENT_PROBE:
2189 case LTTNG_EVENT_USERSPACE_PROBE:
2190 case LTTNG_EVENT_FUNCTION:
2191 case LTTNG_EVENT_FUNCTION_ENTRY:
2192 case LTTNG_EVENT_TRACEPOINT:
2193 ret = event_kernel_enable_event(kchan, event,
2194 filter_expression, filter);
2195 /* We have passed ownership */
2196 filter_expression = NULL;
2197 filter = NULL;
2198 if (ret != LTTNG_OK) {
2199 if (channel_created) {
2200 /* Let's not leak a useless channel. */
2201 kernel_destroy_channel(kchan);
2202 }
2203 goto error;
2204 }
2205 break;
2206 case LTTNG_EVENT_SYSCALL:
2207 ret = event_kernel_enable_event(kchan, event,
2208 filter_expression, filter);
2209 /* We have passed ownership */
2210 filter_expression = NULL;
2211 filter = NULL;
2212 if (ret != LTTNG_OK) {
2213 goto error;
2214 }
2215 break;
2216 default:
2217 ret = LTTNG_ERR_UNK;
2218 goto error;
2219 }
2220
2221 kernel_wait_quiescent();
2222 break;
2223 }
2224 case LTTNG_DOMAIN_UST:
2225 {
2226 struct ltt_ust_channel *uchan;
2227 struct ltt_ust_session *usess = session->ust_session;
2228
2229 assert(usess);
2230
2231 /*
2232 * If a non-default channel has been created in the
2233 * session, explicitely require that -c chan_name needs
2234 * to be provided.
2235 */
2236 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2237 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2238 goto error;
2239 }
2240
2241 /* Get channel from global UST domain */
2242 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2243 channel_name);
2244 if (uchan == NULL) {
2245 /* Create default channel */
2246 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2247 usess->buffer_type);
2248 if (attr == NULL) {
2249 ret = LTTNG_ERR_FATAL;
2250 goto error;
2251 }
2252 if (lttng_strncpy(attr->name, channel_name,
2253 sizeof(attr->name))) {
2254 ret = LTTNG_ERR_INVALID;
2255 goto error;
2256 }
2257
2258 ret = cmd_enable_channel(session, domain, attr, wpipe);
2259 if (ret != LTTNG_OK) {
2260 goto error;
2261 }
2262
2263 /* Get the newly created channel reference back */
2264 uchan = trace_ust_find_channel_by_name(
2265 usess->domain_global.channels, channel_name);
2266 assert(uchan);
2267 }
2268
2269 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2270 /*
2271 * Don't allow users to add UST events to channels which
2272 * are assigned to a userspace subdomain (JUL, Log4J,
2273 * Python, etc.).
2274 */
2275 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2276 goto error;
2277 }
2278
2279 if (!internal_event) {
2280 /*
2281 * Ensure the event name is not reserved for internal
2282 * use.
2283 */
2284 ret = validate_ust_event_name(event->name);
2285 if (ret) {
2286 WARN("Userspace event name %s failed validation.",
2287 event->name);
2288 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2289 goto error;
2290 }
2291 }
2292
2293 /* At this point, the session and channel exist on the tracer */
2294 ret = event_ust_enable_tracepoint(usess, uchan, event,
2295 filter_expression, filter, exclusion,
2296 internal_event);
2297 /* We have passed ownership */
2298 filter_expression = NULL;
2299 filter = NULL;
2300 exclusion = NULL;
2301 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2302 goto already_enabled;
2303 } else if (ret != LTTNG_OK) {
2304 goto error;
2305 }
2306 break;
2307 }
2308 case LTTNG_DOMAIN_LOG4J:
2309 case LTTNG_DOMAIN_JUL:
2310 case LTTNG_DOMAIN_PYTHON:
2311 {
2312 const char *default_event_name, *default_chan_name;
2313 struct agent *agt;
2314 struct lttng_event uevent;
2315 struct lttng_domain tmp_dom;
2316 struct ltt_ust_session *usess = session->ust_session;
2317
2318 assert(usess);
2319
2320 if (!agent_tracing_is_enabled()) {
2321 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2322 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2323 goto error;
2324 }
2325
2326 agt = trace_ust_find_agent(usess, domain->type);
2327 if (!agt) {
2328 agt = agent_create(domain->type);
2329 if (!agt) {
2330 ret = LTTNG_ERR_NOMEM;
2331 goto error;
2332 }
2333 agent_add(agt, usess->agents);
2334 }
2335
2336 /* Create the default tracepoint. */
2337 memset(&uevent, 0, sizeof(uevent));
2338 uevent.type = LTTNG_EVENT_TRACEPOINT;
2339 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2340 default_event_name = event_get_default_agent_ust_name(
2341 domain->type);
2342 if (!default_event_name) {
2343 ret = LTTNG_ERR_FATAL;
2344 goto error;
2345 }
2346 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2347 uevent.name[sizeof(uevent.name) - 1] = '\0';
2348
2349 /*
2350 * The domain type is changed because we are about to enable the
2351 * default channel and event for the JUL domain that are hardcoded.
2352 * This happens in the UST domain.
2353 */
2354 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2355 tmp_dom.type = LTTNG_DOMAIN_UST;
2356
2357 switch (domain->type) {
2358 case LTTNG_DOMAIN_LOG4J:
2359 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2360 break;
2361 case LTTNG_DOMAIN_JUL:
2362 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2363 break;
2364 case LTTNG_DOMAIN_PYTHON:
2365 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2366 break;
2367 default:
2368 /* The switch/case we are in makes this impossible */
2369 assert(0);
2370 }
2371
2372 {
2373 char *filter_expression_copy = NULL;
2374 struct lttng_filter_bytecode *filter_copy = NULL;
2375
2376 if (filter) {
2377 const size_t filter_size = sizeof(
2378 struct lttng_filter_bytecode)
2379 + filter->len;
2380
2381 filter_copy = zmalloc(filter_size);
2382 if (!filter_copy) {
2383 ret = LTTNG_ERR_NOMEM;
2384 goto error;
2385 }
2386 memcpy(filter_copy, filter, filter_size);
2387
2388 filter_expression_copy =
2389 strdup(filter_expression);
2390 if (!filter_expression) {
2391 ret = LTTNG_ERR_NOMEM;
2392 }
2393
2394 if (!filter_expression_copy || !filter_copy) {
2395 free(filter_expression_copy);
2396 free(filter_copy);
2397 goto error;
2398 }
2399 }
2400
2401 ret = cmd_enable_event_internal(session, &tmp_dom,
2402 (char *) default_chan_name,
2403 &uevent, filter_expression_copy,
2404 filter_copy, NULL, wpipe);
2405 }
2406
2407 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2408 goto already_enabled;
2409 } else if (ret != LTTNG_OK) {
2410 goto error;
2411 }
2412
2413 /* The wild card * means that everything should be enabled. */
2414 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2415 ret = event_agent_enable_all(usess, agt, event, filter,
2416 filter_expression);
2417 } else {
2418 ret = event_agent_enable(usess, agt, event, filter,
2419 filter_expression);
2420 }
2421 filter = NULL;
2422 filter_expression = NULL;
2423 if (ret != LTTNG_OK) {
2424 goto error;
2425 }
2426
2427 break;
2428 }
2429 default:
2430 ret = LTTNG_ERR_UND;
2431 goto error;
2432 }
2433
2434 ret = LTTNG_OK;
2435
2436 already_enabled:
2437 error:
2438 free(filter_expression);
2439 free(filter);
2440 free(exclusion);
2441 channel_attr_destroy(attr);
2442 rcu_read_unlock();
2443 return ret;
2444 }
2445
2446 /*
2447 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2448 * We own filter, exclusion, and filter_expression.
2449 */
2450 int cmd_enable_event(struct ltt_session *session,
2451 const struct lttng_domain *domain,
2452 char *channel_name, struct lttng_event *event,
2453 char *filter_expression,
2454 struct lttng_filter_bytecode *filter,
2455 struct lttng_event_exclusion *exclusion,
2456 int wpipe)
2457 {
2458 return _cmd_enable_event(session, domain, channel_name, event,
2459 filter_expression, filter, exclusion, wpipe, false);
2460 }
2461
2462 /*
2463 * Enable an event which is internal to LTTng. An internal should
2464 * never be made visible to clients and are immune to checks such as
2465 * reserved names.
2466 */
2467 static int cmd_enable_event_internal(struct ltt_session *session,
2468 const struct lttng_domain *domain,
2469 char *channel_name, struct lttng_event *event,
2470 char *filter_expression,
2471 struct lttng_filter_bytecode *filter,
2472 struct lttng_event_exclusion *exclusion,
2473 int wpipe)
2474 {
2475 return _cmd_enable_event(session, domain, channel_name, event,
2476 filter_expression, filter, exclusion, wpipe, true);
2477 }
2478
2479 /*
2480 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2481 */
2482 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2483 struct lttng_event **events)
2484 {
2485 int ret;
2486 ssize_t nb_events = 0;
2487
2488 switch (domain) {
2489 case LTTNG_DOMAIN_KERNEL:
2490 nb_events = kernel_list_events(events);
2491 if (nb_events < 0) {
2492 ret = LTTNG_ERR_KERN_LIST_FAIL;
2493 goto error;
2494 }
2495 break;
2496 case LTTNG_DOMAIN_UST:
2497 nb_events = ust_app_list_events(events);
2498 if (nb_events < 0) {
2499 ret = LTTNG_ERR_UST_LIST_FAIL;
2500 goto error;
2501 }
2502 break;
2503 case LTTNG_DOMAIN_LOG4J:
2504 case LTTNG_DOMAIN_JUL:
2505 case LTTNG_DOMAIN_PYTHON:
2506 nb_events = agent_list_events(events, domain);
2507 if (nb_events < 0) {
2508 ret = LTTNG_ERR_UST_LIST_FAIL;
2509 goto error;
2510 }
2511 break;
2512 default:
2513 ret = LTTNG_ERR_UND;
2514 goto error;
2515 }
2516
2517 return nb_events;
2518
2519 error:
2520 /* Return negative value to differentiate return code */
2521 return -ret;
2522 }
2523
2524 /*
2525 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2526 */
2527 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2528 struct lttng_event_field **fields)
2529 {
2530 int ret;
2531 ssize_t nb_fields = 0;
2532
2533 switch (domain) {
2534 case LTTNG_DOMAIN_UST:
2535 nb_fields = ust_app_list_event_fields(fields);
2536 if (nb_fields < 0) {
2537 ret = LTTNG_ERR_UST_LIST_FAIL;
2538 goto error;
2539 }
2540 break;
2541 case LTTNG_DOMAIN_KERNEL:
2542 default: /* fall-through */
2543 ret = LTTNG_ERR_UND;
2544 goto error;
2545 }
2546
2547 return nb_fields;
2548
2549 error:
2550 /* Return negative value to differentiate return code */
2551 return -ret;
2552 }
2553
2554 ssize_t cmd_list_syscalls(struct lttng_event **events)
2555 {
2556 return syscall_table_list(events);
2557 }
2558
2559 /*
2560 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2561 *
2562 * Called with session lock held.
2563 */
2564 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2565 enum lttng_domain_type domain, int32_t **pids)
2566 {
2567 int ret;
2568 ssize_t nr_pids = 0;
2569
2570 switch (domain) {
2571 case LTTNG_DOMAIN_KERNEL:
2572 {
2573 struct ltt_kernel_session *ksess;
2574
2575 ksess = session->kernel_session;
2576 nr_pids = kernel_list_tracker_pids(ksess, pids);
2577 if (nr_pids < 0) {
2578 ret = LTTNG_ERR_KERN_LIST_FAIL;
2579 goto error;
2580 }
2581 break;
2582 }
2583 case LTTNG_DOMAIN_UST:
2584 {
2585 struct ltt_ust_session *usess;
2586
2587 usess = session->ust_session;
2588 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2589 if (nr_pids < 0) {
2590 ret = LTTNG_ERR_UST_LIST_FAIL;
2591 goto error;
2592 }
2593 break;
2594 }
2595 case LTTNG_DOMAIN_LOG4J:
2596 case LTTNG_DOMAIN_JUL:
2597 case LTTNG_DOMAIN_PYTHON:
2598 default:
2599 ret = LTTNG_ERR_UND;
2600 goto error;
2601 }
2602
2603 return nr_pids;
2604
2605 error:
2606 /* Return negative value to differentiate return code */
2607 return -ret;
2608 }
2609
2610 /*
2611 * Command LTTNG_START_TRACE processed by the client thread.
2612 *
2613 * Called with session mutex held.
2614 */
2615 int cmd_start_trace(struct ltt_session *session)
2616 {
2617 enum lttng_error_code ret;
2618 unsigned long nb_chan = 0;
2619 struct ltt_kernel_session *ksession;
2620 struct ltt_ust_session *usess;
2621 const bool session_rotated_after_last_stop =
2622 session->rotated_after_last_stop;
2623
2624 assert(session);
2625
2626 /* Ease our life a bit ;) */
2627 ksession = session->kernel_session;
2628 usess = session->ust_session;
2629
2630 /* Is the session already started? */
2631 if (session->active) {
2632 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2633 goto error;
2634 }
2635
2636 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2637 !session->current_trace_chunk) {
2638 /*
2639 * A rotation was launched while the session was stopped and
2640 * it has not been completed yet. It is not possible to start
2641 * the session since starting the session here would require a
2642 * rotation from "NULL" to a new trace chunk. That rotation
2643 * would overlap with the ongoing rotation, which is not
2644 * supported.
2645 */
2646 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2647 session->name);
2648 ret = LTTNG_ERR_ROTATION_PENDING;
2649 goto error;
2650 }
2651
2652 /*
2653 * Starting a session without channel is useless since after that it's not
2654 * possible to enable channel thus inform the client.
2655 */
2656 if (usess && usess->domain_global.channels) {
2657 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2658 }
2659 if (ksession) {
2660 nb_chan += ksession->channel_count;
2661 }
2662 if (!nb_chan) {
2663 ret = LTTNG_ERR_NO_CHANNEL;
2664 goto error;
2665 }
2666
2667 session->active = 1;
2668 session->rotated_after_last_stop = false;
2669 if (session->output_traces && !session->current_trace_chunk) {
2670 if (!session->has_been_started) {
2671 struct lttng_trace_chunk *trace_chunk;
2672
2673 DBG("Creating initial trace chunk of session \"%s\"",
2674 session->name);
2675 trace_chunk = session_create_new_trace_chunk(
2676 session, NULL, NULL, NULL);
2677 if (!trace_chunk) {
2678 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2679 goto error;
2680 }
2681 assert(!session->current_trace_chunk);
2682 ret = session_set_trace_chunk(session, trace_chunk,
2683 NULL);
2684 lttng_trace_chunk_put(trace_chunk);
2685 if (ret) {
2686 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2687 goto error;
2688 }
2689 } else {
2690 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2691 session->name);
2692 /*
2693 * Rotate existing streams into the new chunk.
2694 * This is a "quiet" rotation has no client has
2695 * explicitly requested this operation.
2696 *
2697 * There is also no need to wait for the rotation
2698 * to complete as it will happen immediately. No data
2699 * was produced as the session was stopped, so the
2700 * rotation should happen on reception of the command.
2701 */
2702 ret = cmd_rotate_session(session, NULL, true);
2703 if (ret != LTTNG_OK) {
2704 goto error;
2705 }
2706 }
2707 }
2708
2709 /* Kernel tracing */
2710 if (ksession != NULL) {
2711 DBG("Start kernel tracing session %s", session->name);
2712 ret = start_kernel_session(ksession);
2713 if (ret != LTTNG_OK) {
2714 goto error;
2715 }
2716 }
2717
2718 /* Flag session that trace should start automatically */
2719 if (usess) {
2720 int int_ret = ust_app_start_trace_all(usess);
2721
2722 if (int_ret < 0) {
2723 ret = LTTNG_ERR_UST_START_FAIL;
2724 goto error;
2725 }
2726 }
2727
2728 /*
2729 * Clear the flag that indicates that a rotation was done while the
2730 * session was stopped.
2731 */
2732 session->rotated_after_last_stop = false;
2733
2734 if (session->rotate_timer_period) {
2735 int int_ret = timer_session_rotation_schedule_timer_start(
2736 session, session->rotate_timer_period);
2737
2738 if (int_ret < 0) {
2739 ERR("Failed to enable rotate timer");
2740 ret = LTTNG_ERR_UNK;
2741 goto error;
2742 }
2743 }
2744
2745 ret = LTTNG_OK;
2746
2747 error:
2748 if (ret == LTTNG_OK) {
2749 /* Flag this after a successful start. */
2750 session->has_been_started |= 1;
2751 } else {
2752 session->active = 0;
2753 /* Restore initial state on error. */
2754 session->rotated_after_last_stop =
2755 session_rotated_after_last_stop;
2756 }
2757 return ret;
2758 }
2759
2760 /*
2761 * Command LTTNG_STOP_TRACE processed by the client thread.
2762 */
2763 int cmd_stop_trace(struct ltt_session *session)
2764 {
2765 int ret;
2766 struct ltt_kernel_session *ksession;
2767 struct ltt_ust_session *usess;
2768
2769 assert(session);
2770
2771 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2772 /* Short cut */
2773 ksession = session->kernel_session;
2774 usess = session->ust_session;
2775
2776 /* Session is not active. Skip everythong and inform the client. */
2777 if (!session->active) {
2778 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2779 goto error;
2780 }
2781
2782 ret = stop_kernel_session(ksession);
2783 if (ret != LTTNG_OK) {
2784 goto error;
2785 }
2786
2787 if (usess && usess->active) {
2788 ret = ust_app_stop_trace_all(usess);
2789 if (ret < 0) {
2790 ret = LTTNG_ERR_UST_STOP_FAIL;
2791 goto error;
2792 }
2793 }
2794
2795 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2796 session->id);
2797 /* Flag inactive after a successful stop. */
2798 session->active = 0;
2799 ret = LTTNG_OK;
2800
2801 error:
2802 return ret;
2803 }
2804
2805 /*
2806 * Set the base_path of the session only if subdir of a control uris is set.
2807 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2808 */
2809 static int set_session_base_path_from_uris(struct ltt_session *session,
2810 size_t nb_uri,
2811 struct lttng_uri *uris)
2812 {
2813 int ret;
2814 size_t i;
2815
2816 for (i = 0; i < nb_uri; i++) {
2817 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2818 uris[i].subdir[0] == '\0') {
2819 /* Not interested in these URIs */
2820 continue;
2821 }
2822
2823 if (session->base_path != NULL) {
2824 free(session->base_path);
2825 session->base_path = NULL;
2826 }
2827
2828 /* Set session base_path */
2829 session->base_path = strdup(uris[i].subdir);
2830 if (!session->base_path) {
2831 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2832 uris[i].subdir, session->name);
2833 ret = LTTNG_ERR_NOMEM;
2834 goto error;
2835 }
2836 DBG2("Setting base path \"%s\" for session \"%s\"",
2837 session->base_path, session->name);
2838 }
2839 ret = LTTNG_OK;
2840 error:
2841 return ret;
2842 }
2843
2844 /*
2845 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2846 */
2847 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2848 struct lttng_uri *uris)
2849 {
2850 int ret, i;
2851 struct ltt_kernel_session *ksess = session->kernel_session;
2852 struct ltt_ust_session *usess = session->ust_session;
2853
2854 assert(session);
2855 assert(uris);
2856 assert(nb_uri > 0);
2857
2858 /* Can't set consumer URI if the session is active. */
2859 if (session->active) {
2860 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2861 goto error;
2862 }
2863
2864 /*
2865 * Set the session base path if any. This is done inside
2866 * cmd_set_consumer_uri to preserve backward compatibility of the
2867 * previous session creation api vs the session descriptor api.
2868 */
2869 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2870 if (ret != LTTNG_OK) {
2871 goto error;
2872 }
2873
2874 /* Set the "global" consumer URIs */
2875 for (i = 0; i < nb_uri; i++) {
2876 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2877 LTTNG_DOMAIN_NONE);
2878 if (ret != LTTNG_OK) {
2879 goto error;
2880 }
2881 }
2882
2883 /* Set UST session URIs */
2884 if (session->ust_session) {
2885 for (i = 0; i < nb_uri; i++) {
2886 ret = add_uri_to_consumer(session,
2887 session->ust_session->consumer,
2888 &uris[i], LTTNG_DOMAIN_UST);
2889 if (ret != LTTNG_OK) {
2890 goto error;
2891 }
2892 }
2893 }
2894
2895 /* Set kernel session URIs */
2896 if (session->kernel_session) {
2897 for (i = 0; i < nb_uri; i++) {
2898 ret = add_uri_to_consumer(session,
2899 session->kernel_session->consumer,
2900 &uris[i], LTTNG_DOMAIN_KERNEL);
2901 if (ret != LTTNG_OK) {
2902 goto error;
2903 }
2904 }
2905 }
2906
2907 /*
2908 * Make sure to set the session in output mode after we set URI since a
2909 * session can be created without URL (thus flagged in no output mode).
2910 */
2911 session->output_traces = 1;
2912 if (ksess) {
2913 ksess->output_traces = 1;
2914 }
2915
2916 if (usess) {
2917 usess->output_traces = 1;
2918 }
2919
2920 /* All good! */
2921 ret = LTTNG_OK;
2922
2923 error:
2924 return ret;
2925 }
2926
2927 static
2928 enum lttng_error_code set_session_output_from_descriptor(
2929 struct ltt_session *session,
2930 const struct lttng_session_descriptor *descriptor)
2931 {
2932 int ret;
2933 enum lttng_error_code ret_code = LTTNG_OK;
2934 enum lttng_session_descriptor_type session_type =
2935 lttng_session_descriptor_get_type(descriptor);
2936 enum lttng_session_descriptor_output_type output_type =
2937 lttng_session_descriptor_get_output_type(descriptor);
2938 struct lttng_uri uris[2] = {};
2939 size_t uri_count = 0;
2940
2941 switch (output_type) {
2942 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2943 goto end;
2944 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2945 lttng_session_descriptor_get_local_output_uri(descriptor,
2946 &uris[0]);
2947 uri_count = 1;
2948 break;
2949 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2950 lttng_session_descriptor_get_network_output_uris(descriptor,
2951 &uris[0], &uris[1]);
2952 uri_count = 2;
2953 break;
2954 default:
2955 ret_code = LTTNG_ERR_INVALID;
2956 goto end;
2957 }
2958
2959 switch (session_type) {
2960 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2961 {
2962 struct snapshot_output *new_output = NULL;
2963
2964 new_output = snapshot_output_alloc();
2965 if (!new_output) {
2966 ret_code = LTTNG_ERR_NOMEM;
2967 goto end;
2968 }
2969
2970 ret = snapshot_output_init_with_uri(session,
2971 DEFAULT_SNAPSHOT_MAX_SIZE,
2972 NULL, uris, uri_count, session->consumer,
2973 new_output, &session->snapshot);
2974 if (ret < 0) {
2975 ret_code = (ret == -ENOMEM) ?
2976 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2977 snapshot_output_destroy(new_output);
2978 goto end;
2979 }
2980 snapshot_add_output(&session->snapshot, new_output);
2981 break;
2982 }
2983 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2984 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2985 {
2986 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2987 break;
2988 }
2989 default:
2990 ret_code = LTTNG_ERR_INVALID;
2991 goto end;
2992 }
2993 end:
2994 return ret_code;
2995 }
2996
2997 static
2998 enum lttng_error_code cmd_create_session_from_descriptor(
2999 struct lttng_session_descriptor *descriptor,
3000 const lttng_sock_cred *creds,
3001 const char *home_path)
3002 {
3003 int ret;
3004 enum lttng_error_code ret_code;
3005 const char *session_name;
3006 struct ltt_session *new_session = NULL;
3007 enum lttng_session_descriptor_status descriptor_status;
3008
3009 session_lock_list();
3010 if (home_path) {
3011 if (*home_path != '/') {
3012 ERR("Home path provided by client is not absolute");
3013 ret_code = LTTNG_ERR_INVALID;
3014 goto end;
3015 }
3016 }
3017
3018 descriptor_status = lttng_session_descriptor_get_session_name(
3019 descriptor, &session_name);
3020 switch (descriptor_status) {
3021 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3022 break;
3023 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3024 session_name = NULL;
3025 break;
3026 default:
3027 ret_code = LTTNG_ERR_INVALID;
3028 goto end;
3029 }
3030
3031 ret_code = session_create(session_name, creds->uid, creds->gid,
3032 &new_session);
3033 if (ret_code != LTTNG_OK) {
3034 goto end;
3035 }
3036
3037 if (!session_name) {
3038 ret = lttng_session_descriptor_set_session_name(descriptor,
3039 new_session->name);
3040 if (ret) {
3041 ret_code = LTTNG_ERR_SESSION_FAIL;
3042 goto end;
3043 }
3044 }
3045
3046 if (!lttng_session_descriptor_is_output_destination_initialized(
3047 descriptor)) {
3048 /*
3049 * Only include the session's creation time in the output
3050 * destination if the name of the session itself was
3051 * not auto-generated.
3052 */
3053 ret_code = lttng_session_descriptor_set_default_output(
3054 descriptor,
3055 session_name ? &new_session->creation_time : NULL,
3056 home_path);
3057 if (ret_code != LTTNG_OK) {
3058 goto end;
3059 }
3060 } else {
3061 new_session->has_user_specified_directory =
3062 lttng_session_descriptor_has_output_directory(
3063 descriptor);
3064 }
3065
3066 switch (lttng_session_descriptor_get_type(descriptor)) {
3067 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3068 new_session->snapshot_mode = 1;
3069 break;
3070 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3071 new_session->live_timer =
3072 lttng_session_descriptor_live_get_timer_interval(
3073 descriptor);
3074 break;
3075 default:
3076 break;
3077 }
3078
3079 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3080 if (ret_code != LTTNG_OK) {
3081 goto end;
3082 }
3083 new_session->consumer->enabled = 1;
3084 ret_code = LTTNG_OK;
3085 end:
3086 /* Release reference provided by the session_create function. */
3087 session_put(new_session);
3088 if (ret_code != LTTNG_OK && new_session) {
3089 /* Release the global reference on error. */
3090 session_destroy(new_session);
3091 }
3092 session_unlock_list();
3093 return ret_code;
3094 }
3095
3096 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3097 struct lttng_session_descriptor **return_descriptor)
3098 {
3099 int ret;
3100 size_t payload_size;
3101 struct lttng_dynamic_buffer payload;
3102 struct lttng_buffer_view home_dir_view;
3103 struct lttng_buffer_view session_descriptor_view;
3104 struct lttng_session_descriptor *session_descriptor = NULL;
3105 enum lttng_error_code ret_code;
3106
3107 lttng_dynamic_buffer_init(&payload);
3108 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
3109 LTTNG_PATH_MAX) {
3110 ret_code = LTTNG_ERR_INVALID;
3111 goto error;
3112 }
3113 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3114 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3115 ret_code = LTTNG_ERR_INVALID;
3116 goto error;
3117 }
3118
3119 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3120 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3121 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3122 if (ret) {
3123 ret_code = LTTNG_ERR_NOMEM;
3124 goto error;
3125 }
3126
3127 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3128 if (ret <= 0) {
3129 ERR("Reception of session descriptor failed, aborting.");
3130 ret_code = LTTNG_ERR_SESSION_FAIL;
3131 goto error;
3132 }
3133
3134 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3135 &payload,
3136 0,
3137 cmd_ctx->lsm->u.create_session.home_dir_size);
3138 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3139 &payload,
3140 cmd_ctx->lsm->u.create_session.home_dir_size,
3141 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3142
3143 ret = lttng_session_descriptor_create_from_buffer(
3144 &session_descriptor_view, &session_descriptor);
3145 if (ret < 0) {
3146 ERR("Failed to create session descriptor from payload of \"create session\" command");
3147 ret_code = LTTNG_ERR_INVALID;
3148 goto error;
3149 }
3150
3151 /*
3152 * Sets the descriptor's auto-generated properties (name, output) if
3153 * needed.
3154 */
3155 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3156 &cmd_ctx->creds,
3157 home_dir_view.size ? home_dir_view.data : NULL);
3158 if (ret_code != LTTNG_OK) {
3159 goto error;
3160 }
3161
3162 ret_code = LTTNG_OK;
3163 *return_descriptor = session_descriptor;
3164 session_descriptor = NULL;
3165 error:
3166 lttng_dynamic_buffer_reset(&payload);
3167 lttng_session_descriptor_destroy(session_descriptor);
3168 return ret_code;
3169 }
3170
3171 static
3172 void cmd_destroy_session_reply(const struct ltt_session *session,
3173 void *_reply_context)
3174 {
3175 int ret;
3176 ssize_t comm_ret;
3177 const struct cmd_destroy_session_reply_context *reply_context =
3178 _reply_context;
3179 struct lttng_dynamic_buffer payload;
3180 struct lttcomm_session_destroy_command_header cmd_header;
3181 struct lttng_trace_archive_location *location = NULL;
3182 struct lttcomm_lttng_msg llm = {
3183 .cmd_type = LTTNG_DESTROY_SESSION,
3184 .ret_code = reply_context->destruction_status,
3185 .pid = UINT32_MAX,
3186 .cmd_header_size =
3187 sizeof(struct lttcomm_session_destroy_command_header),
3188 .data_size = 0,
3189 };
3190 size_t payload_size_before_location;
3191
3192 lttng_dynamic_buffer_init(&payload);
3193
3194 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3195 if (ret) {
3196 ERR("Failed to append session destruction message");
3197 goto error;
3198 }
3199
3200 cmd_header.rotation_state =
3201 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3202 session->rotation_state :
3203 LTTNG_ROTATION_STATE_NO_ROTATION);
3204 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3205 sizeof(cmd_header));
3206 if (ret) {
3207 ERR("Failed to append session destruction command header");
3208 goto error;
3209 }
3210
3211 if (!reply_context->implicit_rotation_on_destroy) {
3212 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3213 session->name);
3214 goto send_reply;
3215 }
3216 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3217 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3218 session->name);
3219 goto send_reply;
3220 }
3221
3222 location = session_get_trace_archive_location(session);
3223 if (!location) {
3224 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3225 session->name);
3226 goto error;
3227 }
3228
3229 payload_size_before_location = payload.size;
3230 comm_ret = lttng_trace_archive_location_serialize(location,
3231 &payload);
3232 if (comm_ret < 0) {
3233 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3234 session->name);
3235 goto error;
3236 }
3237 /* Update the message to indicate the location's length. */
3238 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3239 payload.size - payload_size_before_location;
3240 send_reply:
3241 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3242 payload.data, payload.size);
3243 if (comm_ret != (ssize_t) payload.size) {
3244 ERR("Failed to send result of the destruction of session \"%s\" to client",
3245 session->name);
3246 }
3247 error:
3248 ret = close(reply_context->reply_sock_fd);
3249 if (ret) {
3250 PERROR("Failed to close client socket in deferred session destroy reply");
3251 }
3252 lttng_dynamic_buffer_reset(&payload);
3253 free(_reply_context);
3254 }
3255
3256 /*
3257 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3258 *
3259 * Called with session lock held.
3260 */
3261 int cmd_destroy_session(struct ltt_session *session,
3262 struct notification_thread_handle *notification_thread_handle,
3263 int *sock_fd)
3264 {
3265 int ret;
3266 enum lttng_error_code destruction_last_error = LTTNG_OK;
3267 struct cmd_destroy_session_reply_context *reply_context = NULL;
3268
3269 if (sock_fd) {
3270 reply_context = zmalloc(sizeof(*reply_context));
3271 if (!reply_context) {
3272 ret = LTTNG_ERR_NOMEM;
3273 goto end;
3274 }
3275 reply_context->reply_sock_fd = *sock_fd;
3276 }
3277
3278 /* Safety net */
3279 assert(session);
3280
3281 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3282 session->id);
3283 if (session->active) {
3284 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3285 session->name);
3286 ret = cmd_stop_trace(session);
3287 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3288 /* Carry on with the destruction of the session. */
3289 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3290 session->name, lttng_strerror(-ret));
3291 destruction_last_error = ret;
3292 }
3293 }
3294
3295 if (session->rotation_schedule_timer_enabled) {
3296 if (timer_session_rotation_schedule_timer_stop(
3297 session)) {
3298 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3299 session->name);
3300 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3301 }
3302 }
3303
3304 if (session->rotate_size) {
3305 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3306 session->rotate_size = 0;
3307 }
3308
3309 if (session->most_recent_chunk_id.is_set &&
3310 session->most_recent_chunk_id.value != 0 &&
3311 session->current_trace_chunk && session->output_traces) {
3312 /*
3313 * Perform a last rotation on destruction if rotations have
3314 * occurred during the session's lifetime.
3315 */
3316 ret = cmd_rotate_session(session, NULL, false);
3317 if (ret != LTTNG_OK) {
3318 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3319 session->name, lttng_strerror(-ret));
3320 destruction_last_error = -ret;
3321 }
3322 if (reply_context) {
3323 reply_context->implicit_rotation_on_destroy = true;
3324 }
3325 } else if (session->has_been_started && session->current_trace_chunk) {
3326 /*
3327 * The user has not triggered a session rotation. However, to
3328 * ensure all data has been consumed, the session is rotated
3329 * to a 'null' trace chunk before it is destroyed.
3330 *
3331 * This is a "quiet" rotation meaning that no notification is
3332 * emitted and no renaming of the current trace chunk takes
3333 * place.
3334 */
3335 ret = cmd_rotate_session(session, NULL, true);
3336 if (ret != LTTNG_OK) {
3337 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3338 session->name, lttng_strerror(-ret));
3339 destruction_last_error = -ret;
3340 }
3341 }
3342
3343 if (session->shm_path[0]) {
3344 /*
3345 * When a session is created with an explicit shm_path,
3346 * the consumer daemon will create its shared memory files
3347 * at that location and will *not* unlink them. This is normal
3348 * as the intention of that feature is to make it possible
3349 * to retrieve the content of those files should a crash occur.
3350 *
3351 * To ensure the content of those files can be used, the
3352 * sessiond daemon will replicate the content of the metadata
3353 * cache in a metadata file.
3354 *
3355 * On clean-up, it is expected that the consumer daemon will
3356 * unlink the shared memory files and that the session daemon
3357 * will unlink the metadata file. Then, the session's directory
3358 * in the shm path can be removed.
3359 *
3360 * Unfortunately, a flaw in the design of the sessiond's and
3361 * consumerd's tear down of channels makes it impossible to
3362 * determine when the sessiond _and_ the consumerd have both
3363 * destroyed their representation of a channel. For one, the
3364 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3365 * callbacks in both daemons.
3366 *
3367 * However, it is also impossible for the sessiond to know when
3368 * the consumer daemon is done destroying its channel(s) since
3369 * it occurs as a reaction to the closing of the channel's file
3370 * descriptor. There is no resulting communication initiated
3371 * from the consumerd to the sessiond to confirm that the
3372 * operation is completed (and was successful).
3373 *
3374 * Until this is all fixed, the session daemon checks for the
3375 * removal of the session's shm path which makes it possible
3376 * to safely advertise a session as having been destroyed.
3377 *
3378 * Prior to this fix, it was not possible to reliably save
3379 * a session making use of the --shm-path option, destroy it,
3380 * and load it again. This is because the creation of the
3381 * session would fail upon seeing the session's shm path
3382 * already in existence.
3383 *
3384 * Note that none of the error paths in the check for the
3385 * directory's existence return an error. This is normal
3386 * as there isn't much that can be done. The session will
3387 * be destroyed properly, except that we can't offer the
3388 * guarantee that the same session can be re-created.
3389 */
3390 current_completion_handler = &destroy_completion_handler.handler;
3391 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3392 session->shm_path,
3393 sizeof(destroy_completion_handler.shm_path));
3394 assert(!ret);
3395 }
3396
3397 /*
3398 * The session is destroyed. However, note that the command context
3399 * still holds a reference to the session, thus delaying its destruction
3400 * _at least_ up to the point when that reference is released.
3401 */
3402 session_destroy(session);
3403 if (reply_context) {
3404 reply_context->destruction_status = destruction_last_error;
3405 ret = session_add_destroy_notifier(session,
3406 cmd_destroy_session_reply,
3407 (void *) reply_context);
3408 if (ret) {
3409 ret = LTTNG_ERR_FATAL;
3410 goto end;
3411 } else {
3412 *sock_fd = -1;
3413 }
3414 }
3415 ret = LTTNG_OK;
3416 end:
3417 return ret;
3418 }
3419
3420 /*
3421 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3422 */
3423 int cmd_register_consumer(struct ltt_session *session,
3424 enum lttng_domain_type domain, const char *sock_path,
3425 struct consumer_data *cdata)
3426 {
3427 int ret, sock;
3428 struct consumer_socket *socket = NULL;
3429
3430 assert(session);
3431 assert(cdata);
3432 assert(sock_path);
3433
3434 switch (domain) {
3435 case LTTNG_DOMAIN_KERNEL:
3436 {
3437 struct ltt_kernel_session *ksess = session->kernel_session;
3438
3439 assert(ksess);
3440
3441 /* Can't register a consumer if there is already one */
3442 if (ksess->consumer_fds_sent != 0) {
3443 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3444 goto error;
3445 }
3446
3447 sock = lttcomm_connect_unix_sock(sock_path);
3448 if (sock < 0) {
3449 ret = LTTNG_ERR_CONNECT_FAIL;
3450 goto error;
3451 }
3452 cdata->cmd_sock = sock;
3453
3454 socket = consumer_allocate_socket(&cdata->cmd_sock);
3455 if (socket == NULL) {
3456 ret = close(sock);
3457 if (ret < 0) {
3458 PERROR("close register consumer");
3459 }
3460 cdata->cmd_sock = -1;
3461 ret = LTTNG_ERR_FATAL;
3462 goto error;
3463 }
3464
3465 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3466 if (socket->lock == NULL) {
3467 PERROR("zmalloc pthread mutex");
3468 ret = LTTNG_ERR_FATAL;
3469 goto error;
3470 }
3471 pthread_mutex_init(socket->lock, NULL);
3472 socket->registered = 1;
3473
3474 rcu_read_lock();
3475 consumer_add_socket(socket, ksess->consumer);
3476 rcu_read_unlock();
3477
3478 pthread_mutex_lock(&cdata->pid_mutex);
3479 cdata->pid = -1;
3480 pthread_mutex_unlock(&cdata->pid_mutex);
3481
3482 break;
3483 }
3484 default:
3485 /* TODO: Userspace tracing */
3486 ret = LTTNG_ERR_UND;
3487 goto error;
3488 }
3489
3490 return LTTNG_OK;
3491
3492 error:
3493 if (socket) {
3494 consumer_destroy_socket(socket);
3495 }
3496 return ret;
3497 }
3498
3499 /*
3500 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3501 */
3502 ssize_t cmd_list_domains(struct ltt_session *session,
3503 struct lttng_domain **domains)
3504 {
3505 int ret, index = 0;
3506 ssize_t nb_dom = 0;
3507 struct agent *agt;
3508 struct lttng_ht_iter iter;
3509
3510 if (session->kernel_session != NULL) {
3511 DBG3("Listing domains found kernel domain");
3512 nb_dom++;
3513 }
3514
3515 if (session->ust_session != NULL) {
3516 DBG3("Listing domains found UST global domain");
3517 nb_dom++;
3518
3519 rcu_read_lock();
3520 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3521 agt, node.node) {
3522 if (agt->being_used) {
3523 nb_dom++;
3524 }
3525 }
3526 rcu_read_unlock();
3527 }
3528
3529 if (!nb_dom) {
3530 goto end;
3531 }
3532
3533 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3534 if (*domains == NULL) {
3535 ret = LTTNG_ERR_FATAL;
3536 goto error;
3537 }
3538
3539 if (session->kernel_session != NULL) {
3540 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3541
3542 /* Kernel session buffer type is always GLOBAL */
3543 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3544
3545 index++;
3546 }
3547
3548 if (session->ust_session != NULL) {
3549 (*domains)[index].type = LTTNG_DOMAIN_UST;
3550 (*domains)[index].buf_type = session->ust_session->buffer_type;
3551 index++;
3552
3553 rcu_read_lock();
3554 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3555 agt, node.node) {
3556 if (agt->being_used) {
3557 (*domains)[index].type = agt->domain;
3558 (*domains)[index].buf_type = session->ust_session->buffer_type;
3559 index++;
3560 }
3561 }
3562 rcu_read_unlock();
3563 }
3564 end:
3565 return nb_dom;
3566
3567 error:
3568 /* Return negative value to differentiate return code */
3569 return -ret;
3570 }
3571
3572
3573 /*
3574 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3575 */
3576 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3577 struct ltt_session *session, struct lttng_channel **channels)
3578 {
3579 ssize_t nb_chan = 0, payload_size = 0, ret;
3580
3581 switch (domain) {
3582 case LTTNG_DOMAIN_KERNEL:
3583 if (session->kernel_session != NULL) {
3584 nb_chan = session->kernel_session->channel_count;
3585 }
3586 DBG3("Number of kernel channels %zd", nb_chan);
3587 if (nb_chan <= 0) {
3588 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3589 goto end;
3590 }
3591 break;
3592 case LTTNG_DOMAIN_UST:
3593 if (session->ust_session != NULL) {
3594 rcu_read_lock();
3595 nb_chan = lttng_ht_get_count(
3596 session->ust_session->domain_global.channels);
3597 rcu_read_unlock();
3598 }
3599 DBG3("Number of UST global channels %zd", nb_chan);
3600 if (nb_chan < 0) {
3601 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3602 goto end;
3603 }
3604 break;
3605 default:
3606 ret = -LTTNG_ERR_UND;
3607 goto end;
3608 }
3609
3610 if (nb_chan > 0) {
3611 const size_t channel_size = sizeof(struct lttng_channel) +
3612 sizeof(struct lttng_channel_extended);
3613 struct lttng_channel_extended *channel_exts;
3614
3615 payload_size = nb_chan * channel_size;
3616 *channels = zmalloc(payload_size);
3617 if (*channels == NULL) {
3618 ret = -LTTNG_ERR_FATAL;
3619 goto end;
3620 }
3621
3622 channel_exts = ((void *) *channels) +
3623 (nb_chan * sizeof(struct lttng_channel));
3624 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3625 if (ret != LTTNG_OK) {
3626 free(*channels);
3627 *channels = NULL;
3628 goto end;
3629 }
3630 } else {
3631 *channels = NULL;
3632 }
3633
3634 ret = payload_size;
3635 end:
3636 return ret;
3637 }
3638
3639 /*
3640 * Command LTTNG_LIST_EVENTS processed by the client thread.
3641 */
3642 ssize_t cmd_list_events(enum lttng_domain_type domain,
3643 struct ltt_session *session, char *channel_name,
3644 struct lttng_event **events, size_t *total_size)
3645 {
3646 int ret = 0;
3647 ssize_t nb_event = 0;
3648
3649 switch (domain) {
3650 case LTTNG_DOMAIN_KERNEL:
3651 if (session->kernel_session != NULL) {
3652 nb_event = list_lttng_kernel_events(channel_name,
3653 session->kernel_session, events,
3654 total_size);
3655 }
3656 break;
3657 case LTTNG_DOMAIN_UST:
3658 {
3659 if (session->ust_session != NULL) {
3660 nb_event = list_lttng_ust_global_events(channel_name,
3661 &session->ust_session->domain_global, events,
3662 total_size);
3663 }
3664 break;
3665 }
3666 case LTTNG_DOMAIN_LOG4J:
3667 case LTTNG_DOMAIN_JUL:
3668 case LTTNG_DOMAIN_PYTHON:
3669 if (session->ust_session) {
3670 struct lttng_ht_iter iter;
3671 struct agent *agt;
3672
3673 rcu_read_lock();
3674 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3675 &iter.iter, agt, node.node) {
3676 if (agt->domain == domain) {
3677 nb_event = list_lttng_agent_events(
3678 agt, events,
3679 total_size);
3680 break;
3681 }
3682 }
3683 rcu_read_unlock();
3684 }
3685 break;
3686 default:
3687 ret = LTTNG_ERR_UND;
3688 goto error;
3689 }
3690
3691 return nb_event;
3692
3693 error:
3694 /* Return negative value to differentiate return code */
3695 return -ret;
3696 }
3697
3698 /*
3699 * Using the session list, filled a lttng_session array to send back to the
3700 * client for session listing.
3701 *
3702 * The session list lock MUST be acquired before calling this function. Use
3703 * session_lock_list() and session_unlock_list().
3704 */
3705 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3706 size_t session_count, uid_t uid, gid_t gid)
3707 {
3708 int ret;
3709 unsigned int i = 0;
3710 struct ltt_session *session;
3711 struct ltt_session_list *list = session_get_list();
3712 struct lttng_session_extended *extended =
3713 (typeof(extended)) (&sessions[session_count]);
3714
3715 DBG("Getting all available session for UID %d GID %d",
3716 uid, gid);
3717 /*
3718 * Iterate over session list and append data after the control struct in
3719 * the buffer.
3720 */
3721 cds_list_for_each_entry(session, &list->head, list) {
3722 if (!session_get(session)) {
3723 continue;
3724 }
3725 /*
3726 * Only list the sessions the user can control.
3727 */
3728 if (!session_access_ok(session, uid, gid) ||
3729 session->destroyed) {
3730 session_put(session);
3731 continue;
3732 }
3733
3734 struct ltt_kernel_session *ksess = session->kernel_session;
3735 struct ltt_ust_session *usess = session->ust_session;
3736
3737 if (session->consumer->type == CONSUMER_DST_NET ||
3738 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3739 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3740 ret = build_network_session_path(sessions[i].path,
3741 sizeof(sessions[i].path), session);
3742 } else {
3743 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3744 session->consumer->dst.session_root_path);
3745 }
3746 if (ret < 0) {
3747 PERROR("snprintf session path");
3748 session_put(session);
3749 continue;
3750 }
3751
3752 strncpy(sessions[i].name, session->name, NAME_MAX);
3753 sessions[i].name[NAME_MAX - 1] = '\0';
3754 sessions[i].enabled = session->active;
3755 sessions[i].snapshot_mode = session->snapshot_mode;
3756 sessions[i].live_timer_interval = session->live_timer;
3757 extended[i].creation_time.value = (uint64_t) session->creation_time;
3758 extended[i].creation_time.is_set = 1;
3759 i++;
3760 session_put(session);
3761 }
3762 }
3763
3764 /*
3765 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3766 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3767 */
3768 int cmd_data_pending(struct ltt_session *session)
3769 {
3770 int ret;
3771 struct ltt_kernel_session *ksess = session->kernel_session;
3772 struct ltt_ust_session *usess = session->ust_session;
3773
3774 assert(session);
3775
3776 DBG("Data pending for session %s", session->name);
3777
3778 /* Session MUST be stopped to ask for data availability. */
3779 if (session->active) {
3780 ret = LTTNG_ERR_SESSION_STARTED;
3781 goto error;
3782 } else {
3783 /*
3784 * If stopped, just make sure we've started before else the above call
3785 * will always send that there is data pending.
3786 *
3787 * The consumer assumes that when the data pending command is received,
3788 * the trace has been started before or else no output data is written
3789 * by the streams which is a condition for data pending. So, this is
3790 * *VERY* important that we don't ask the consumer before a start
3791 * trace.
3792 */
3793 if (!session->has_been_started) {
3794 ret = 0;
3795 goto error;
3796 }
3797 }
3798
3799 /* A rotation is still pending, we have to wait. */
3800 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3801 DBG("Rotate still pending for session %s", session->name);
3802 ret = 1;
3803 goto error;
3804 }
3805
3806 if (ksess && ksess->consumer) {
3807 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3808 if (ret == 1) {
3809 /* Data is still being extracted for the kernel. */
3810 goto error;
3811 }
3812 }
3813
3814 if (usess && usess->consumer) {
3815 ret = consumer_is_data_pending(usess->id, usess->consumer);
3816 if (ret == 1) {
3817 /* Data is still being extracted for the kernel. */
3818 goto error;
3819 }
3820 }
3821
3822 /* Data is ready to be read by a viewer */
3823 ret = 0;
3824
3825 error:
3826 return ret;
3827 }
3828
3829 /*
3830 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3831 *
3832 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3833 */
3834 int cmd_snapshot_add_output(struct ltt_session *session,
3835 const struct lttng_snapshot_output *output, uint32_t *id)
3836 {
3837 int ret;
3838 struct snapshot_output *new_output;
3839
3840 assert(session);
3841 assert(output);
3842
3843 DBG("Cmd snapshot add output for session %s", session->name);
3844
3845 /*
3846 * Can't create an output if the session is not set in no-output mode.
3847 */
3848 if (session->output_traces) {
3849 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3850 goto error;
3851 }
3852
3853 if (session->has_non_mmap_channel) {
3854 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3855 goto error;
3856 }
3857
3858 /* Only one output is allowed until we have the "tee" feature. */
3859 if (session->snapshot.nb_output == 1) {
3860 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3861 goto error;
3862 }
3863
3864 new_output = snapshot_output_alloc();
3865 if (!new_output) {
3866 ret = LTTNG_ERR_NOMEM;
3867 goto error;
3868 }
3869
3870 ret = snapshot_output_init(session, output->max_size, output->name,
3871 output->ctrl_url, output->data_url, session->consumer, new_output,
3872 &session->snapshot);
3873 if (ret < 0) {
3874 if (ret == -ENOMEM) {
3875 ret = LTTNG_ERR_NOMEM;
3876 } else {
3877 ret = LTTNG_ERR_INVALID;
3878 }
3879 goto free_error;
3880 }
3881
3882 rcu_read_lock();
3883 snapshot_add_output(&session->snapshot, new_output);
3884 if (id) {
3885 *id = new_output->id;
3886 }
3887 rcu_read_unlock();
3888
3889 return LTTNG_OK;
3890
3891 free_error:
3892 snapshot_output_destroy(new_output);
3893 error:
3894 return ret;
3895 }
3896
3897 /*
3898 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3899 *
3900 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3901 */
3902 int cmd_snapshot_del_output(struct ltt_session *session,
3903 const struct lttng_snapshot_output *output)
3904 {
3905 int ret;
3906 struct snapshot_output *sout = NULL;
3907
3908 assert(session);
3909 assert(output);
3910
3911 rcu_read_lock();
3912
3913 /*
3914 * Permission denied to create an output if the session is not
3915 * set in no output mode.
3916 */
3917 if (session->output_traces) {
3918 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3919 goto error;
3920 }
3921
3922 if (output->id) {
3923 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3924 session->name);
3925 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3926 } else if (*output->name != '\0') {
3927 DBG("Cmd snapshot del output name %s for session %s", output->name,
3928 session->name);
3929 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3930 }
3931 if (!sout) {
3932 ret = LTTNG_ERR_INVALID;
3933 goto error;
3934 }
3935
3936 snapshot_delete_output(&session->snapshot, sout);
3937 snapshot_output_destroy(sout);
3938 ret = LTTNG_OK;
3939
3940 error:
3941 rcu_read_unlock();
3942 return ret;
3943 }
3944
3945 /*
3946 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3947 *
3948 * If no output is available, outputs is untouched and 0 is returned.
3949 *
3950 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3951 */
3952 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3953 struct lttng_snapshot_output **outputs)
3954 {
3955 int ret, idx = 0;
3956 struct lttng_snapshot_output *list = NULL;
3957 struct lttng_ht_iter iter;
3958 struct snapshot_output *output;
3959
3960 assert(session);
3961 assert(outputs);
3962
3963 DBG("Cmd snapshot list outputs for session %s", session->name);
3964
3965 /*
3966 * Permission denied to create an output if the session is not
3967 * set in no output mode.
3968 */
3969 if (session->output_traces) {
3970 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3971 goto end;
3972 }
3973
3974 if (session->snapshot.nb_output == 0) {
3975 ret = 0;
3976 goto end;
3977 }
3978
3979 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3980 if (!list) {
3981 ret = -LTTNG_ERR_NOMEM;
3982 goto end;
3983 }
3984
3985 /* Copy list from session to the new list object. */
3986 rcu_read_lock();
3987 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3988 output, node.node) {
3989 assert(output->consumer);
3990 list[idx].id = output->id;
3991 list[idx].max_size = output->max_size;
3992 if (lttng_strncpy(list[idx].name, output->name,
3993 sizeof(list[idx].name))) {
3994 ret = -LTTNG_ERR_INVALID;
3995 goto error;
3996 }
3997 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3998 if (lttng_strncpy(list[idx].ctrl_url,
3999 output->consumer->dst.session_root_path,
4000 sizeof(list[idx].ctrl_url))) {
4001 ret = -LTTNG_ERR_INVALID;
4002 goto error;
4003 }
4004 } else {
4005 /* Control URI. */
4006 ret = uri_to_str_url(&output->consumer->dst.net.control,
4007 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
4008 if (ret < 0) {
4009 ret = -LTTNG_ERR_NOMEM;
4010 goto error;
4011 }
4012
4013 /* Data URI. */
4014 ret = uri_to_str_url(&output->consumer->dst.net.data,
4015 list[idx].data_url, sizeof(list[idx].data_url));
4016 if (ret < 0) {
4017 ret = -LTTNG_ERR_NOMEM;
4018 goto error;
4019 }
4020 }
4021 idx++;
4022 }
4023
4024 *outputs = list;
4025 list = NULL;
4026 ret = session->snapshot.nb_output;
4027 error:
4028 rcu_read_unlock();
4029 free(list);
4030 end:
4031 return ret;
4032 }
4033
4034 /*
4035 * Check if we can regenerate the metadata for this session.
4036 * Only kernel, UST per-uid and non-live sessions are supported.
4037 *
4038 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
4039 */
4040 static
4041 int check_regenerate_metadata_support(struct ltt_session *session)
4042 {
4043 int ret;
4044
4045 assert(session);
4046
4047 if (session->live_timer != 0) {
4048 ret = LTTNG_ERR_LIVE_SESSION;
4049 goto end;
4050 }
4051 if (!session->active) {
4052 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4053 goto end;
4054 }
4055 if (session->ust_session) {
4056 switch (session->ust_session->buffer_type) {
4057 case LTTNG_BUFFER_PER_UID:
4058 break;
4059 case LTTNG_BUFFER_PER_PID:
4060 ret = LTTNG_ERR_PER_PID_SESSION;
4061 goto end;
4062 default:
4063 assert(0);
4064 ret = LTTNG_ERR_UNK;
4065 goto end;
4066 }
4067 }
4068 if (session->consumer->type == CONSUMER_DST_NET &&
4069 session->consumer->relay_minor_version < 8) {
4070 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
4071 goto end;
4072 }
4073 ret = 0;
4074
4075 end:
4076 return ret;
4077 }
4078
4079 static
4080 int clear_metadata_file(int fd)
4081 {
4082 int ret;
4083 off_t lseek_ret;
4084
4085 lseek_ret = lseek(fd, 0, SEEK_SET);
4086 if (lseek_ret < 0) {
4087 PERROR("lseek");
4088 ret = -1;
4089 goto end;
4090 }
4091
4092 ret = ftruncate(fd, 0);
4093 if (ret < 0) {
4094 PERROR("ftruncate");
4095 goto end;
4096 }
4097
4098 end:
4099 return ret;
4100 }
4101
4102 static
4103 int ust_regenerate_metadata(struct ltt_ust_session *usess)
4104 {
4105 int ret = 0;
4106 struct buffer_reg_uid *uid_reg = NULL;
4107 struct buffer_reg_session *session_reg = NULL;
4108
4109 rcu_read_lock();
4110 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
4111 struct ust_registry_session *registry;
4112 struct ust_registry_channel *chan;
4113 struct lttng_ht_iter iter_chan;
4114
4115 session_reg = uid_reg->registry;
4116 registry = session_reg->reg.ust;
4117
4118 pthread_mutex_lock(&registry->lock);
4119 registry->metadata_len_sent = 0;
4120 memset(registry->metadata, 0, registry->metadata_alloc_len);
4121 registry->metadata_len = 0;
4122 registry->metadata_version++;
4123 if (registry->metadata_fd > 0) {
4124 /* Clear the metadata file's content. */
4125 ret = clear_metadata_file(registry->metadata_fd);
4126 if (ret) {
4127 pthread_mutex_unlock(&registry->lock);
4128 goto end;
4129 }
4130 }
4131
4132 ret = ust_metadata_session_statedump(registry, NULL,
4133 registry->major, registry->minor);
4134 if (ret) {
4135 pthread_mutex_unlock(&registry->lock);
4136 ERR("Failed to generate session metadata (err = %d)",
4137 ret);
4138 goto end;
4139 }
4140 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
4141 chan, node.node) {
4142 struct ust_registry_event *event;
4143 struct lttng_ht_iter iter_event;
4144
4145 ret = ust_metadata_channel_statedump(registry, chan);
4146 if (ret) {
4147 pthread_mutex_unlock(&registry->lock);
4148 ERR("Failed to generate channel metadata "
4149 "(err = %d)", ret);
4150 goto end;
4151 }
4152 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
4153 event, node.node) {
4154 ret = ust_metadata_event_statedump(registry,
4155 chan, event);
4156 if (ret) {
4157 pthread_mutex_unlock(&registry->lock);
4158 ERR("Failed to generate event metadata "
4159 "(err = %d)", ret);
4160 goto end;
4161 }
4162 }
4163 }
4164 pthread_mutex_unlock(&registry->lock);
4165 }
4166
4167 end:
4168 rcu_read_unlock();
4169 return ret;
4170 }
4171
4172 /*
4173 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4174 *
4175 * Ask the consumer to truncate the existing metadata file(s) and
4176 * then regenerate the metadata. Live and per-pid sessions are not
4177 * supported and return an error.
4178 *
4179 * Return 0 on success or else a LTTNG_ERR code.
4180 */
4181 int cmd_regenerate_metadata(struct ltt_session *session)
4182 {
4183 int ret;
4184
4185 assert(session);
4186
4187 ret = check_regenerate_metadata_support(session);
4188 if (ret) {
4189 goto end;
4190 }
4191
4192 if (session->kernel_session) {
4193 ret = kernctl_session_regenerate_metadata(
4194 session->kernel_session->fd);
4195 if (ret < 0) {
4196 ERR("Failed to regenerate the kernel metadata");
4197 goto end;
4198 }
4199 }
4200
4201 if (session->ust_session) {
4202 ret = ust_regenerate_metadata(session->ust_session);
4203 if (ret < 0) {
4204 ERR("Failed to regenerate the UST metadata");
4205 goto end;
4206 }
4207 }
4208 DBG("Cmd metadata regenerate for session %s", session->name);
4209 ret = LTTNG_OK;
4210
4211 end:
4212 return ret;
4213 }
4214
4215 /*
4216 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4217 *
4218 * Ask the tracer to regenerate a new statedump.
4219 *
4220 * Return 0 on success or else a LTTNG_ERR code.
4221 */
4222 int cmd_regenerate_statedump(struct ltt_session *session)
4223 {
4224 int ret;
4225
4226 assert(session);
4227
4228 if (!session->active) {
4229 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4230 goto end;
4231 }
4232
4233 if (session->kernel_session) {
4234 ret = kernctl_session_regenerate_statedump(
4235 session->kernel_session->fd);
4236 /*
4237 * Currently, the statedump in kernel can only fail if out
4238 * of memory.
4239 */
4240 if (ret < 0) {
4241 if (ret == -ENOMEM) {
4242 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4243 } else {
4244 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4245 }
4246 ERR("Failed to regenerate the kernel statedump");
4247 goto end;
4248 }
4249 }
4250
4251 if (session->ust_session) {
4252 ret = ust_app_regenerate_statedump_all(session->ust_session);
4253 /*
4254 * Currently, the statedump in UST always returns 0.
4255 */
4256 if (ret < 0) {
4257 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4258 ERR("Failed to regenerate the UST statedump");
4259 goto end;
4260 }
4261 }
4262 DBG("Cmd regenerate statedump for session %s", session->name);
4263 ret = LTTNG_OK;
4264
4265 end:
4266 return ret;
4267 }
4268
4269 int cmd_register_trigger(struct command_ctx *cmd_ctx, int sock,
4270 struct notification_thread_handle *notification_thread)
4271 {
4272 int ret;
4273 size_t trigger_len;
4274 ssize_t sock_recv_len;
4275 struct lttng_trigger *trigger = NULL;
4276 struct lttng_buffer_view view;
4277 struct lttng_dynamic_buffer trigger_buffer;
4278
4279 lttng_dynamic_buffer_init(&trigger_buffer);
4280 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4281 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4282 if (ret) {
4283 ret = LTTNG_ERR_NOMEM;
4284 goto end;
4285 }
4286
4287 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4288 trigger_len);
4289 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4290 ERR("Failed to receive \"register trigger\" command payload");
4291 /* TODO: should this be a new error enum ? */
4292 ret = LTTNG_ERR_INVALID_TRIGGER;
4293 goto end;
4294 }
4295
4296 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4297 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4298 trigger_len) {
4299 ERR("Invalid trigger payload received in \"register trigger\" command");
4300 ret = LTTNG_ERR_INVALID_TRIGGER;
4301 goto end;
4302 }
4303
4304 ret = notification_thread_command_register_trigger(notification_thread,
4305 trigger);
4306 /* Ownership of trigger was transferred. */
4307 trigger = NULL;
4308 end:
4309 lttng_trigger_destroy(trigger);
4310 lttng_dynamic_buffer_reset(&trigger_buffer);
4311 return ret;
4312 }
4313
4314 int cmd_unregister_trigger(struct command_ctx *cmd_ctx, int sock,
4315 struct notification_thread_handle *notification_thread)
4316 {
4317 int ret;
4318 size_t trigger_len;
4319 ssize_t sock_recv_len;
4320 struct lttng_trigger *trigger = NULL;
4321 struct lttng_buffer_view view;
4322 struct lttng_dynamic_buffer trigger_buffer;
4323
4324 lttng_dynamic_buffer_init(&trigger_buffer);
4325 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4326 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4327 if (ret) {
4328 ret = LTTNG_ERR_NOMEM;
4329 goto end;
4330 }
4331
4332 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4333 trigger_len);
4334 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4335 ERR("Failed to receive \"unregister trigger\" command payload");
4336 /* TODO: should this be a new error enum ? */
4337 ret = LTTNG_ERR_INVALID_TRIGGER;
4338 goto end;
4339 }
4340
4341 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4342 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4343 trigger_len) {
4344 ERR("Invalid trigger payload received in \"unregister trigger\" command");
4345 ret = LTTNG_ERR_INVALID_TRIGGER;
4346 goto end;
4347 }
4348
4349 ret = notification_thread_command_unregister_trigger(notification_thread,
4350 trigger);
4351 end:
4352 lttng_trigger_destroy(trigger);
4353 lttng_dynamic_buffer_reset(&trigger_buffer);
4354 return ret;
4355 }
4356
4357 /*
4358 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4359 * snapshot output is *not* set with a remote destination.
4360 *
4361 * Return LTTNG_OK on success or a LTTNG_ERR code.
4362 */
4363 static enum lttng_error_code set_relayd_for_snapshot(
4364 struct consumer_output *output,
4365 const struct ltt_session *session)
4366 {
4367 enum lttng_error_code status = LTTNG_OK;
4368 struct lttng_ht_iter iter;
4369 struct consumer_socket *socket;
4370 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4371 const char *base_path;
4372
4373 assert(output);
4374 assert(session);
4375
4376 DBG2("Set relayd object from snapshot output");
4377
4378 if (session->current_trace_chunk) {
4379 enum lttng_trace_chunk_status chunk_status =
4380 lttng_trace_chunk_get_id(
4381 session->current_trace_chunk,
4382 &current_chunk_id.value);
4383
4384 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
4385 current_chunk_id.is_set = true;
4386 } else {
4387 ERR("Failed to get current trace chunk id");
4388 status = LTTNG_ERR_UNK;
4389 goto error;
4390 }
4391 }
4392
4393 /* Ignore if snapshot consumer output is not network. */
4394 if (output->type != CONSUMER_DST_NET) {
4395 goto error;
4396 }
4397
4398 /*
4399 * The snapshot record URI base path overrides the session
4400 * base path.
4401 */
4402 if (output->dst.net.control.subdir[0] != '\0') {
4403 base_path = output->dst.net.control.subdir;
4404 } else {
4405 base_path = session->base_path;
4406 }
4407
4408 /*
4409 * For each consumer socket, create and send the relayd object of the
4410 * snapshot output.
4411 */
4412 rcu_read_lock();
4413 cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
4414 socket, node.node) {
4415 pthread_mutex_lock(socket->lock);
4416 status = send_consumer_relayd_sockets(0, session->id,
4417 output, socket,
4418 session->name, session->hostname,
4419 base_path,
4420 session->live_timer,
4421 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
4422 session->creation_time,
4423 session->name_contains_creation_time);
4424 pthread_mutex_unlock(socket->lock);
4425 if (status != LTTNG_OK) {
4426 rcu_read_unlock();
4427 goto error;
4428 }
4429 }
4430 rcu_read_unlock();
4431
4432 error:
4433 return status;
4434 }
4435
4436 /*
4437 * Record a kernel snapshot.
4438 *
4439 * Return LTTNG_OK on success or a LTTNG_ERR code.
4440 */
4441 static enum lttng_error_code record_kernel_snapshot(
4442 struct ltt_kernel_session *ksess,
4443 const struct consumer_output *output,
4444 const struct ltt_session *session,
4445 int wait, uint64_t nb_packets_per_stream)
4446 {
4447 enum lttng_error_code status;
4448
4449 assert(ksess);
4450 assert(output);
4451 assert(session);
4452
4453 status = kernel_snapshot_record(
4454 ksess, output, wait, nb_packets_per_stream);
4455 return status;
4456 }
4457
4458 /*
4459 * Record a UST snapshot.
4460 *
4461 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
4462 */
4463 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
4464 const struct consumer_output *output,
4465 const struct ltt_session *session,
4466 int wait, uint64_t nb_packets_per_stream)
4467 {
4468 enum lttng_error_code status;
4469
4470 assert(usess);
4471 assert(output);
4472 assert(session);
4473
4474 status = ust_app_snapshot_record(
4475 usess, output, wait, nb_packets_per_stream);
4476 return status;
4477 }
4478
4479 static
4480 uint64_t get_session_size_one_more_packet_per_stream(
4481 const struct ltt_session *session, uint64_t cur_nr_packets)
4482 {
4483 uint64_t tot_size = 0;
4484
4485 if (session->kernel_session) {
4486 struct ltt_kernel_channel *chan;
4487 const struct ltt_kernel_session *ksess =
4488 session->kernel_session;
4489
4490 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
4491 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
4492 /*
4493 * Don't take channel into account if we
4494 * already grab all its packets.
4495 */
4496 continue;
4497 }
4498 tot_size += chan->channel->attr.subbuf_size
4499 * chan->stream_count;
4500 }
4501 }
4502
4503 if (session->ust_session) {
4504 const struct ltt_ust_session *usess = session->ust_session;
4505
4506 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
4507 cur_nr_packets);
4508 }
4509
4510 return tot_size;
4511 }
4512
4513 /*
4514 * Calculate the number of packets we can grab from each stream that
4515 * fits within the overall snapshot max size.
4516 *
4517 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
4518 * the number of packets per stream.
4519 *
4520 * TODO: this approach is not perfect: we consider the worse case
4521 * (packet filling the sub-buffers) as an upper bound, but we could do
4522 * better if we do this calculation while we actually grab the packet
4523 * content: we would know how much padding we don't actually store into
4524 * the file.
4525 *
4526 * This algorithm is currently bounded by the number of packets per
4527 * stream.
4528 *
4529 * Since we call this algorithm before actually grabbing the data, it's
4530 * an approximation: for instance, applications could appear/disappear
4531 * in between this call and actually grabbing data.
4532 */
4533 static
4534 int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
4535 uint64_t max_size)
4536 {
4537 int64_t size_left;
4538 uint64_t cur_nb_packets = 0;
4539
4540 if (!max_size) {
4541 return 0; /* Infinite */
4542 }
4543
4544 size_left = max_size;
4545 for (;;) {
4546 uint64_t one_more_packet_tot_size;
4547
4548 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(
4549 session, cur_nb_packets);
4550 if (!one_more_packet_tot_size) {
4551 /* We are already grabbing all packets. */
4552 break;
4553 }
4554 size_left -= one_more_packet_tot_size;
4555 if (size_left < 0) {
4556 break;
4557 }
4558 cur_nb_packets++;
4559 }
4560 if (!cur_nb_packets) {
4561 /* Not enough room to grab one packet of each stream, error. */
4562 return -1;
4563 }
4564 return cur_nb_packets;
4565 }
4566
4567 static
4568 enum lttng_error_code snapshot_record(struct ltt_session *session,
4569 const struct snapshot_output *snapshot_output, int wait)
4570 {
4571 int64_t nb_packets_per_stream;
4572 char snapshot_chunk_name[LTTNG_NAME_MAX];
4573 int ret;
4574 enum lttng_error_code ret_code = LTTNG_OK;
4575 struct lttng_trace_chunk *snapshot_trace_chunk;
4576 struct consumer_output *original_ust_consumer_output = NULL;
4577 struct consumer_output *original_kernel_consumer_output = NULL;
4578 struct consumer_output *snapshot_ust_consumer_output = NULL;
4579 struct consumer_output *snapshot_kernel_consumer_output = NULL;
4580
4581 ret = snprintf(snapshot_chunk_name, sizeof(snapshot_chunk_name),
4582 "%s-%s-%" PRIu64,
4583 snapshot_output->name,
4584 snapshot_output->datetime,
4585 snapshot_output->nb_snapshot);
4586 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
4587 ERR("Failed to format snapshot name");
4588 ret_code = LTTNG_ERR_INVALID;
4589 goto error;
4590 }
4591 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
4592 snapshot_output->name, session->name,
4593 snapshot_chunk_name);
4594 if (!session->kernel_session && !session->ust_session) {
4595 ERR("Failed to record snapshot as no channels exist");
4596 ret_code = LTTNG_ERR_NO_CHANNEL;
4597 goto error;
4598 }
4599
4600 if (session->kernel_session) {
4601 original_kernel_consumer_output =
4602 session->kernel_session->consumer;
4603 snapshot_kernel_consumer_output =
4604 consumer_copy_output(snapshot_output->consumer);
4605 strcpy(snapshot_kernel_consumer_output->chunk_path,
4606 snapshot_chunk_name);
4607 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
4608 original_kernel_consumer_output);
4609 if (ret < 0) {
4610 ERR("Failed to copy consumer sockets from snapshot output configuration");
4611 ret_code = LTTNG_ERR_NOMEM;
4612 goto error;
4613 }
4614 ret_code = set_relayd_for_snapshot(
4615 snapshot_kernel_consumer_output, session);
4616 if (ret_code != LTTNG_OK) {
4617 ERR("Failed to setup relay daemon for kernel tracer snapshot");
4618 goto error;
4619 }
4620 session->kernel_session->consumer =
4621 snapshot_kernel_consumer_output;
4622 }
4623 if (session->ust_session) {
4624 original_ust_consumer_output = session->ust_session->consumer;
4625 snapshot_ust_consumer_output =
4626 consumer_copy_output(snapshot_output->consumer);
4627 strcpy(snapshot_ust_consumer_output->chunk_path,
4628 snapshot_chunk_name);
4629 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
4630 original_ust_consumer_output);
4631 if (ret < 0) {
4632 ERR("Failed to copy consumer sockets from snapshot output configuration");
4633 ret_code = LTTNG_ERR_NOMEM;
4634 goto error;
4635 }
4636 ret_code = set_relayd_for_snapshot(
4637 snapshot_ust_consumer_output, session);
4638 if (ret_code != LTTNG_OK) {
4639 ERR("Failed to setup relay daemon for userspace tracer snapshot");
4640 goto error;
4641 }
4642 session->ust_session->consumer =
4643 snapshot_ust_consumer_output;
4644 }
4645
4646 snapshot_trace_chunk = session_create_new_trace_chunk(session,
4647 snapshot_kernel_consumer_output ?:
4648 snapshot_ust_consumer_output,
4649 consumer_output_get_base_path(
4650 snapshot_output->consumer),
4651 snapshot_chunk_name);
4652 if (!snapshot_trace_chunk) {
4653 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
4654 session->name);
4655 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
4656 goto error;
4657 }
4658 assert(!session->current_trace_chunk);
4659 ret = session_set_trace_chunk(session, snapshot_trace_chunk, NULL);
4660 lttng_trace_chunk_put(snapshot_trace_chunk);
4661 snapshot_trace_chunk = NULL;
4662 if (ret) {
4663 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
4664 session->name);
4665 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4666 goto error;
4667 }
4668
4669 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4670 snapshot_output->max_size);
4671 if (nb_packets_per_stream < 0) {
4672 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
4673 goto error;
4674 }
4675
4676 if (session->kernel_session) {
4677 ret_code = record_kernel_snapshot(session->kernel_session,
4678 snapshot_kernel_consumer_output, session,
4679 wait, nb_packets_per_stream);
4680 if (ret_code != LTTNG_OK) {
4681 goto error;
4682 }
4683 }
4684
4685 if (session->ust_session) {
4686 ret_code = record_ust_snapshot(session->ust_session,
4687 snapshot_ust_consumer_output, session,
4688 wait, nb_packets_per_stream);
4689 if (ret_code != LTTNG_OK) {
4690 goto error;
4691 }
4692 }
4693
4694 if (session_close_trace_chunk(
4695 session, session->current_trace_chunk, NULL, NULL)) {
4696 /*
4697 * Don't goto end; make sure the chunk is closed for the session
4698 * to allow future snapshots.
4699 */
4700 ERR("Failed to close snapshot trace chunk of session \"%s\"",
4701 session->name);
4702 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
4703 }
4704 if (session_set_trace_chunk(session, NULL, NULL)) {
4705 ERR("Failed to release the current trace chunk of session \"%s\"",
4706 session->name);
4707 ret_code = LTTNG_ERR_UNK;
4708 }
4709 error:
4710 if (original_ust_consumer_output) {
4711 session->ust_session->consumer = original_ust_consumer_output;
4712 }
4713 if (original_kernel_consumer_output) {
4714 session->kernel_session->consumer =
4715 original_kernel_consumer_output;
4716 }
4717 consumer_output_put(snapshot_ust_consumer_output);
4718 consumer_output_put(snapshot_kernel_consumer_output);
4719 return ret_code;
4720 }
4721
4722 /*
4723 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
4724 *
4725 * The wait parameter is ignored so this call always wait for the snapshot to
4726 * complete before returning.
4727 *
4728 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4729 */
4730 int cmd_snapshot_record(struct ltt_session *session,
4731 const struct lttng_snapshot_output *output, int wait)
4732 {
4733 enum lttng_error_code cmd_ret = LTTNG_OK;
4734 int ret;
4735 unsigned int snapshot_success = 0;
4736 char datetime[16];
4737 struct snapshot_output *tmp_output = NULL;
4738
4739 assert(session);
4740 assert(output);
4741
4742 DBG("Cmd snapshot record for session %s", session->name);
4743
4744 /* Get the datetime for the snapshot output directory. */
4745 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
4746 sizeof(datetime));
4747 if (!ret) {
4748 cmd_ret = LTTNG_ERR_INVALID;
4749 goto error;
4750 }
4751
4752 /*
4753 * Permission denied to create an output if the session is not
4754 * set in no output mode.
4755 */
4756 if (session->output_traces) {
4757 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4758 goto error;
4759 }
4760
4761 /* The session needs to be started at least once. */
4762 if (!session->has_been_started) {
4763 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4764 goto error;
4765 }
4766
4767 /* Use temporary output for the session. */
4768 if (*output->ctrl_url != '\0') {
4769 tmp_output = snapshot_output_alloc();
4770 if (!tmp_output) {
4771 cmd_ret = LTTNG_ERR_NOMEM;
4772 goto error;
4773 }
4774
4775 ret = snapshot_output_init(session, output->max_size,
4776 output->name,
4777 output->ctrl_url, output->data_url,
4778 session->consumer,
4779 tmp_output, NULL);
4780 if (ret < 0) {
4781 if (ret == -ENOMEM) {
4782 cmd_ret = LTTNG_ERR_NOMEM;
4783 } else {
4784 cmd_ret = LTTNG_ERR_INVALID;
4785 }
4786 goto error;
4787 }
4788 /* Use the global session count for the temporary snapshot. */
4789 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
4790
4791 /* Use the global datetime */
4792 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
4793 cmd_ret = snapshot_record(session, tmp_output, wait);
4794 if (cmd_ret != LTTNG_OK) {
4795 goto error;
4796 }
4797 snapshot_success = 1;
4798 } else {
4799 struct snapshot_output *sout;
4800 struct lttng_ht_iter iter;
4801
4802 rcu_read_lock();
4803 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
4804 &iter.iter, sout, node.node) {
4805 struct snapshot_output output_copy;
4806
4807 /*
4808 * Make a local copy of the output and override output
4809 * parameters with those provided as part of the
4810 * command.
4811 */
4812 memcpy(&output_copy, sout, sizeof(output_copy));
4813
4814 if (output->max_size != (uint64_t) -1ULL) {
4815 output_copy.max_size = output->max_size;
4816 }
4817
4818 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
4819 memcpy(output_copy.datetime, datetime,
4820 sizeof(datetime));
4821
4822 /* Use temporary name. */
4823 if (*output->name != '\0') {
4824 if (lttng_strncpy(output_copy.name,
4825 output->name,
4826 sizeof(output_copy.name))) {
4827 cmd_ret = LTTNG_ERR_INVALID;
4828 rcu_read_unlock();
4829 goto error;
4830 }
4831 }
4832
4833 cmd_ret = snapshot_record(session, &output_copy, wait);
4834 if (cmd_ret != LTTNG_OK) {
4835 rcu_read_unlock();
4836 goto error;
4837 }
4838 snapshot_success = 1;
4839 }
4840 rcu_read_unlock();
4841 }
4842
4843 if (snapshot_success) {
4844 session->snapshot.nb_snapshot++;
4845 } else {
4846 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
4847 }
4848
4849 error:
4850 if (tmp_output) {
4851 snapshot_output_destroy(tmp_output);
4852 }
4853 return cmd_ret;
4854 }
4855
4856 /*
4857 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
4858 */
4859 int cmd_set_session_shm_path(struct ltt_session *session,
4860 const char *shm_path)
4861 {
4862 /* Safety net */
4863 assert(session);
4864
4865 /*
4866 * Can only set shm path before session is started.
4867 */
4868 if (session->has_been_started) {
4869 return LTTNG_ERR_SESSION_STARTED;
4870 }
4871
4872 strncpy(session->shm_path, shm_path,
4873 sizeof(session->shm_path));
4874 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
4875
4876 return 0;
4877 }
4878
4879 /*
4880 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
4881 *
4882 * Ask the consumer to rotate the session output directory.
4883 * The session lock must be held.
4884 *
4885 * Returns LTTNG_OK on success or else a negative LTTng error code.
4886 */
4887 int cmd_rotate_session(struct ltt_session *session,
4888 struct lttng_rotate_session_return *rotate_return,
4889 bool quiet_rotation)
4890 {
4891 int ret;
4892 uint64_t ongoing_rotation_chunk_id;
4893 enum lttng_error_code cmd_ret = LTTNG_OK;
4894 struct lttng_trace_chunk *chunk_being_archived = NULL;
4895 struct lttng_trace_chunk *new_trace_chunk = NULL;
4896 enum lttng_trace_chunk_status chunk_status;
4897 bool failed_to_rotate = false;
4898 enum lttng_error_code rotation_fail_code = LTTNG_OK;
4899
4900 assert(session);
4901
4902 if (!session->has_been_started) {
4903 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4904 goto end;
4905 }
4906
4907 /*
4908 * Explicit rotation is not supported for live sessions.
4909 * However, live sessions can perform a quiet rotation on
4910 * destroy.
4911 * Rotation is not supported for snapshot traces (no output).
4912 */
4913 if ((!quiet_rotation && session->live_timer) ||
4914 !session->output_traces) {
4915 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
4916 goto end;
4917 }
4918
4919 /* Unsupported feature in lttng-relayd before 2.11. */
4920 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
4921 (session->consumer->relay_major_version == 2 &&
4922 session->consumer->relay_minor_version < 11)) {
4923 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
4924 goto end;
4925 }
4926
4927 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
4928 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
4929 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
4930 goto end;
4931 }
4932
4933 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
4934 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
4935 session->name);
4936 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
4937 goto end;
4938 }
4939
4940 /*
4941 * After a stop, we only allow one rotation to occur, the other ones are
4942 * useless until a new start.
4943 */
4944 if (session->rotated_after_last_stop) {
4945 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
4946 session->name);
4947 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
4948 goto end;
4949 }
4950 if (session->active) {
4951 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
4952 NULL, NULL);
4953 if (!new_trace_chunk) {
4954 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
4955 goto error;
4956 }
4957 }
4958
4959 /*
4960 * The current trace chunk becomes the chunk being archived.
4961 *
4962 * After this point, "chunk_being_archived" must absolutely
4963 * be closed on the consumer(s), otherwise it will never be
4964 * cleaned-up, which will result in a leak.
4965 */
4966 ret = session_set_trace_chunk(session, new_trace_chunk,
4967 &chunk_being_archived);
4968 if (ret) {
4969 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4970 goto error;
4971 }
4972
4973 if (session->kernel_session) {
4974 cmd_ret = kernel_rotate_session(session);
4975 if (cmd_ret != LTTNG_OK) {
4976 failed_to_rotate = true;
4977 rotation_fail_code = cmd_ret;
4978 }
4979 }
4980 if (session->ust_session) {
4981 cmd_ret = ust_app_rotate_session(session);
4982 if (cmd_ret != LTTNG_OK) {
4983 failed_to_rotate = true;
4984 rotation_fail_code = cmd_ret;
4985 }
4986 }
4987
4988 if (!session->active) {
4989 session->rotated_after_last_stop = true;
4990 }
4991
4992 if (!chunk_being_archived) {
4993 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
4994 session->name);
4995 if (failed_to_rotate) {
4996 cmd_ret = rotation_fail_code;
4997 goto error;
4998 }
4999 cmd_ret = LTTNG_OK;
5000 goto end;
5001 }
5002
5003 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5004 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
5005 &ongoing_rotation_chunk_id);
5006 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5007
5008 ret = session_close_trace_chunk(session, chunk_being_archived,
5009 quiet_rotation ?
5010 NULL :
5011 &((enum lttng_trace_chunk_command_type){
5012 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED}),
5013 session->last_chunk_path);
5014 if (ret) {
5015 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5016 goto error;
5017 }
5018
5019 if (failed_to_rotate) {
5020 cmd_ret = rotation_fail_code;
5021 goto error;
5022 }
5023
5024 session->quiet_rotation = quiet_rotation;
5025 ret = timer_session_rotation_pending_check_start(session,
5026 DEFAULT_ROTATE_PENDING_TIMER);
5027 if (ret) {
5028 cmd_ret = LTTNG_ERR_UNK;
5029 goto error;
5030 }
5031
5032 if (rotate_return) {
5033 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5034 }
5035
5036 session->chunk_being_archived = chunk_being_archived;
5037 chunk_being_archived = NULL;
5038 if (!quiet_rotation) {
5039 ret = notification_thread_command_session_rotation_ongoing(
5040 notification_thread_handle,
5041 session->name, session->uid, session->gid,
5042 ongoing_rotation_chunk_id);
5043 if (ret != LTTNG_OK) {
5044 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5045 session->name);
5046 cmd_ret = ret;
5047 }
5048 }
5049
5050 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5051 session->name, ongoing_rotation_chunk_id);
5052 end:
5053 lttng_trace_chunk_put(new_trace_chunk);
5054 lttng_trace_chunk_put(chunk_being_archived);
5055 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5056 return ret;
5057 error:
5058 if (session_reset_rotation_state(session,
5059 LTTNG_ROTATION_STATE_ERROR)) {
5060 ERR("Failed to reset rotation state of session \"%s\"",
5061 session->name);
5062 }
5063 goto end;
5064 }
5065
5066 /*
5067 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5068 *
5069 * Check if the session has finished its rotation.
5070 *
5071 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5072 */
5073 int cmd_rotate_get_info(struct ltt_session *session,
5074 struct lttng_rotation_get_info_return *info_return,
5075 uint64_t rotation_id)
5076 {
5077 enum lttng_error_code cmd_ret = LTTNG_OK;
5078 enum lttng_rotation_state rotation_state;
5079
5080 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
5081 session->most_recent_chunk_id.value);
5082
5083 if (session->chunk_being_archived) {
5084 enum lttng_trace_chunk_status chunk_status;
5085 uint64_t chunk_id;
5086
5087 chunk_status = lttng_trace_chunk_get_id(
5088 session->chunk_being_archived,
5089 &chunk_id);
5090 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5091
5092 rotation_state = rotation_id == chunk_id ?
5093 LTTNG_ROTATION_STATE_ONGOING :
5094 LTTNG_ROTATION_STATE_EXPIRED;
5095 } else {
5096 if (session->last_archived_chunk_id.is_set &&
5097 rotation_id != session->last_archived_chunk_id.value) {
5098 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5099 } else {
5100 rotation_state = session->rotation_state;
5101 }
5102 }
5103
5104 switch (rotation_state) {
5105 case LTTNG_ROTATION_STATE_NO_ROTATION:
5106 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5107 session->name);
5108 goto end;
5109 case LTTNG_ROTATION_STATE_EXPIRED:
5110 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
5111 rotation_id, session->name);
5112 break;
5113 case LTTNG_ROTATION_STATE_ONGOING:
5114 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5115 rotation_id, session->name);
5116 break;
5117 case LTTNG_ROTATION_STATE_COMPLETED:
5118 {
5119 int fmt_ret;
5120 char *chunk_path;
5121 char *current_tracing_path_reply;
5122 size_t current_tracing_path_reply_len;
5123
5124 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5125 rotation_id, session->name);
5126
5127 switch (session_get_consumer_destination_type(session)) {
5128 case CONSUMER_DST_LOCAL:
5129 current_tracing_path_reply =
5130 info_return->location.local.absolute_path;
5131 current_tracing_path_reply_len =
5132 sizeof(info_return->location.local.absolute_path);
5133 info_return->location_type =
5134 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5135 fmt_ret = asprintf(&chunk_path,
5136 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5137 session_get_base_path(session),
5138 session->last_archived_chunk_name);
5139 if (fmt_ret == -1) {
5140 PERROR("Failed to format the path of the last archived trace chunk");
5141 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5142 cmd_ret = LTTNG_ERR_UNK;
5143 goto end;
5144 }
5145 break;
5146 case CONSUMER_DST_NET:
5147 {
5148 uint16_t ctrl_port, data_port;
5149
5150 current_tracing_path_reply =
5151 info_return->location.relay.relative_path;
5152 current_tracing_path_reply_len =
5153 sizeof(info_return->location.relay.relative_path);
5154 /* Currently the only supported relay protocol. */
5155 info_return->location.relay.protocol =
5156 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5157
5158 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5159 session_get_net_consumer_hostname(session),
5160 sizeof(info_return->location.relay.host));
5161 if (fmt_ret) {
5162 ERR("Failed to copy host name to rotate_get_info reply");
5163 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5164 cmd_ret = LTTNG_ERR_SET_URL;
5165 goto end;
5166 }
5167
5168 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5169 info_return->location.relay.ports.control = ctrl_port;
5170 info_return->location.relay.ports.data = data_port;
5171 info_return->location_type =
5172 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5173 chunk_path = strdup(session->last_chunk_path);
5174 if (!chunk_path) {
5175 ERR("Failed to allocate the path of the last archived trace chunk");
5176 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5177 cmd_ret = LTTNG_ERR_UNK;
5178 goto end;
5179 }
5180 break;
5181 }
5182 default:
5183 abort();
5184 }
5185
5186 fmt_ret = lttng_strncpy(current_tracing_path_reply,
5187 chunk_path, current_tracing_path_reply_len);
5188 free(chunk_path);
5189 if (fmt_ret) {
5190 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5191 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5192 cmd_ret = LTTNG_ERR_UNK;
5193 goto end;
5194 }
5195
5196 break;
5197 }
5198 case LTTNG_ROTATION_STATE_ERROR:
5199 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
5200 rotation_id, session->name);
5201 break;
5202 default:
5203 abort();
5204 }
5205
5206 cmd_ret = LTTNG_OK;
5207 end:
5208 info_return->status = (int32_t) rotation_state;
5209 return cmd_ret;
5210 }
5211
5212 /*
5213 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5214 *
5215 * Configure the automatic rotation parameters.
5216 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5217 * 'activate' to false means deactivate the rotation schedule and validate that
5218 * 'new_value' has the same value as the currently active value.
5219 *
5220 * Return 0 on success or else a positive LTTNG_ERR code.
5221 */
5222 int cmd_rotation_set_schedule(struct ltt_session *session,
5223 bool activate, enum lttng_rotation_schedule_type schedule_type,
5224 uint64_t new_value,
5225 struct notification_thread_handle *notification_thread_handle)
5226 {
5227 int ret;
5228 uint64_t *parameter_value;
5229
5230 assert(session);
5231
5232 DBG("Cmd rotate set schedule session %s", session->name);
5233
5234 if (session->live_timer || !session->output_traces) {
5235 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5236 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5237 goto end;
5238 }
5239
5240 switch (schedule_type) {
5241 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5242 parameter_value = &session->rotate_size;
5243 break;
5244 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5245 parameter_value = &session->rotate_timer_period;
5246 if (new_value >= UINT_MAX) {
5247 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5248 new_value, UINT_MAX);
5249 ret = LTTNG_ERR_INVALID;
5250 goto end;
5251 }
5252 break;
5253 default:
5254 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5255 ret = LTTNG_ERR_INVALID;
5256 goto end;
5257 }
5258
5259 /* Improper use of the API. */
5260 if (new_value == -1ULL) {
5261 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5262 ret = LTTNG_ERR_INVALID;
5263 goto end;
5264 }
5265
5266 /*
5267 * As indicated in struct ltt_session's comments, a value of == 0 means
5268 * this schedule rotation type is not in use.
5269 *
5270 * Reject the command if we were asked to activate a schedule that was
5271 * already active.
5272 */
5273 if (activate && *parameter_value != 0) {
5274 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5275 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5276 goto end;
5277 }
5278
5279 /*
5280 * Reject the command if we were asked to deactivate a schedule that was
5281 * not active.
5282 */
5283 if (!activate && *parameter_value == 0) {
5284 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5285 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5286 goto end;
5287 }
5288
5289 /*
5290 * Reject the command if we were asked to deactivate a schedule that
5291 * doesn't exist.
5292 */
5293 if (!activate && *parameter_value != new_value) {
5294 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5295 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5296 goto end;
5297 }
5298
5299 *parameter_value = activate ? new_value : 0;
5300
5301 switch (schedule_type) {
5302 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5303 if (activate && session->active) {
5304 /*
5305 * Only start the timer if the session is active,
5306 * otherwise it will be started when the session starts.
5307 */
5308 ret = timer_session_rotation_schedule_timer_start(
5309 session, new_value);
5310 if (ret) {
5311 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5312 ret = LTTNG_ERR_UNK;
5313 goto end;
5314 }
5315 } else {
5316 ret = timer_session_rotation_schedule_timer_stop(
5317 session);
5318 if (ret) {
5319 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5320 ret = LTTNG_ERR_UNK;
5321 goto end;
5322 }
5323 }
5324 break;
5325 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5326 if (activate) {
5327 ret = subscribe_session_consumed_size_rotation(session,
5328 new_value, notification_thread_handle);
5329 if (ret) {
5330 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5331 ret = LTTNG_ERR_UNK;
5332 goto end;
5333 }
5334 } else {
5335 ret = unsubscribe_session_consumed_size_rotation(session,
5336 notification_thread_handle);
5337 if (ret) {
5338 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5339 ret = LTTNG_ERR_UNK;
5340 goto end;
5341 }
5342
5343 }
5344 break;
5345 default:
5346 /* Would have been caught before. */
5347 abort();
5348 }
5349
5350 ret = LTTNG_OK;
5351
5352 goto end;
5353
5354 end:
5355 return ret;
5356 }
5357
5358 /* Wait for a given path to be removed before continuing. */
5359 static enum lttng_error_code wait_on_path(void *path_data)
5360 {
5361 const char *shm_path = path_data;
5362
5363 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
5364 shm_path);
5365 while (true) {
5366 int ret;
5367 struct stat st;
5368
5369 ret = stat(shm_path, &st);
5370 if (ret) {
5371 if (errno != ENOENT) {
5372 PERROR("stat() returned an error while checking for the existence of the shm path");
5373 } else {
5374 DBG("shm path no longer exists, completing the destruction of session");
5375 }
5376 break;
5377 } else {
5378 if (!S_ISDIR(st.st_mode)) {
5379 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5380 shm_path);
5381 break;
5382 }
5383 }
5384 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5385 }
5386 return LTTNG_OK;
5387 }
5388
5389 /*
5390 * Returns a pointer to a handler to run on completion of a command.
5391 * Returns NULL if no handler has to be run for the last command executed.
5392 */
5393 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
5394 {
5395 struct cmd_completion_handler *handler = current_completion_handler;
5396
5397 current_completion_handler = NULL;
5398 return handler;
5399 }
5400
5401 /*
5402 * Init command subsystem.
5403 */
5404 void cmd_init(void)
5405 {
5406 /*
5407 * Set network sequence index to 1 for streams to match a relayd
5408 * socket on the consumer side.
5409 */
5410 pthread_mutex_lock(&relayd_net_seq_idx_lock);
5411 relayd_net_seq_idx = 1;
5412 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
5413
5414 DBG("Command subsystem initialized");
5415 }
LTTng tools - Deliverables
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