4447747de752608f08aa02719af5254ab3f2a26c
[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
78 static enum lttng_error_code wait_on_path(void *path);
79
80 /*
81 * Command completion handler that is used by the destroy command
82 * when a session that has a non-default shm_path is being destroyed.
83 *
84 * See comment in cmd_destroy_session() for the rationale.
85 */
86 static struct destroy_completion_handler {
87 struct cmd_completion_handler handler;
88 char shm_path[member_sizeof(struct ltt_session, shm_path)];
89 } destroy_completion_handler = {
90 .handler = {
91 .run = wait_on_path,
92 .data = destroy_completion_handler.shm_path
93 },
94 .shm_path = { 0 },
95 };
96
97 static struct cmd_completion_handler *current_completion_handler;
98
99 /*
100 * Used to keep a unique index for each relayd socket created where this value
101 * is associated with streams on the consumer so it can match the right relayd
102 * to send to. It must be accessed with the relayd_net_seq_idx_lock
103 * held.
104 */
105 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
106 static uint64_t relayd_net_seq_idx;
107
108 static int validate_ust_event_name(const char *);
109 static int cmd_enable_event_internal(struct ltt_session *session,
110 struct lttng_domain *domain,
111 char *channel_name, struct lttng_event *event,
112 char *filter_expression,
113 struct lttng_filter_bytecode *filter,
114 struct lttng_event_exclusion *exclusion,
115 int wpipe);
116
117 /*
118 * Create a session path used by list_lttng_sessions for the case that the
119 * session consumer is on the network.
120 */
121 static int build_network_session_path(char *dst, size_t size,
122 struct ltt_session *session)
123 {
124 int ret, kdata_port, udata_port;
125 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
126 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
127
128 assert(session);
129 assert(dst);
130
131 memset(tmp_urls, 0, sizeof(tmp_urls));
132 memset(tmp_uurl, 0, sizeof(tmp_uurl));
133
134 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
135
136 if (session->kernel_session && session->kernel_session->consumer) {
137 kuri = &session->kernel_session->consumer->dst.net.control;
138 kdata_port = session->kernel_session->consumer->dst.net.data.port;
139 }
140
141 if (session->ust_session && session->ust_session->consumer) {
142 uuri = &session->ust_session->consumer->dst.net.control;
143 udata_port = session->ust_session->consumer->dst.net.data.port;
144 }
145
146 if (uuri == NULL && kuri == NULL) {
147 uri = &session->consumer->dst.net.control;
148 kdata_port = session->consumer->dst.net.data.port;
149 } else if (kuri && uuri) {
150 ret = uri_compare(kuri, uuri);
151 if (ret) {
152 /* Not Equal */
153 uri = kuri;
154 /* Build uuri URL string */
155 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
156 if (ret < 0) {
157 goto error;
158 }
159 } else {
160 uri = kuri;
161 }
162 } else if (kuri && uuri == NULL) {
163 uri = kuri;
164 } else if (uuri && kuri == NULL) {
165 uri = uuri;
166 }
167
168 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
169 if (ret < 0) {
170 goto error;
171 }
172
173 /*
174 * Do we have a UST url set. If yes, this means we have both kernel and UST
175 * to print.
176 */
177 if (*tmp_uurl != '\0') {
178 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
179 tmp_urls, kdata_port, tmp_uurl, udata_port);
180 } else {
181 int dport;
182 if (kuri || (!kuri && !uuri)) {
183 dport = kdata_port;
184 } else {
185 /* No kernel URI, use the UST port. */
186 dport = udata_port;
187 }
188 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
189 }
190
191 error:
192 return ret;
193 }
194
195 /*
196 * Get run-time attributes if the session has been started (discarded events,
197 * lost packets).
198 */
199 static int get_kernel_runtime_stats(struct ltt_session *session,
200 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
201 uint64_t *lost_packets)
202 {
203 int ret;
204
205 if (!session->has_been_started) {
206 ret = 0;
207 *discarded_events = 0;
208 *lost_packets = 0;
209 goto end;
210 }
211
212 ret = consumer_get_discarded_events(session->id, kchan->key,
213 session->kernel_session->consumer,
214 discarded_events);
215 if (ret < 0) {
216 goto end;
217 }
218
219 ret = consumer_get_lost_packets(session->id, kchan->key,
220 session->kernel_session->consumer,
221 lost_packets);
222 if (ret < 0) {
223 goto end;
224 }
225
226 end:
227 return ret;
228 }
229
230 /*
231 * Get run-time attributes if the session has been started (discarded events,
232 * lost packets).
233 */
234 static int get_ust_runtime_stats(struct ltt_session *session,
235 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
236 uint64_t *lost_packets)
237 {
238 int ret;
239 struct ltt_ust_session *usess;
240
241 if (!discarded_events || !lost_packets) {
242 ret = -1;
243 goto end;
244 }
245
246 usess = session->ust_session;
247 assert(discarded_events);
248 assert(lost_packets);
249
250 if (!usess || !session->has_been_started) {
251 *discarded_events = 0;
252 *lost_packets = 0;
253 ret = 0;
254 goto end;
255 }
256
257 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
258 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
259 &usess->buffer_reg_uid_list,
260 usess->consumer, uchan->id,
261 uchan->attr.overwrite,
262 discarded_events,
263 lost_packets);
264 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
265 ret = ust_app_pid_get_channel_runtime_stats(usess,
266 uchan, usess->consumer,
267 uchan->attr.overwrite,
268 discarded_events,
269 lost_packets);
270 if (ret < 0) {
271 goto end;
272 }
273 *discarded_events += uchan->per_pid_closed_app_discarded;
274 *lost_packets += uchan->per_pid_closed_app_lost;
275 } else {
276 ERR("Unsupported buffer type");
277 assert(0);
278 ret = -1;
279 goto end;
280 }
281
282 end:
283 return ret;
284 }
285
286 /*
287 * Fill lttng_channel array of all channels.
288 */
289 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
290 struct ltt_session *session, struct lttng_channel *channels,
291 struct lttng_channel_extended *chan_exts)
292 {
293 int i = 0, ret = 0;
294 struct ltt_kernel_channel *kchan;
295
296 DBG("Listing channels for session %s", session->name);
297
298 switch (domain) {
299 case LTTNG_DOMAIN_KERNEL:
300 /* Kernel channels */
301 if (session->kernel_session != NULL) {
302 cds_list_for_each_entry(kchan,
303 &session->kernel_session->channel_list.head, list) {
304 uint64_t discarded_events, lost_packets;
305 struct lttng_channel_extended *extended;
306
307 extended = (struct lttng_channel_extended *)
308 kchan->channel->attr.extended.ptr;
309
310 ret = get_kernel_runtime_stats(session, kchan,
311 &discarded_events, &lost_packets);
312 if (ret < 0) {
313 goto end;
314 }
315 /* Copy lttng_channel struct to array */
316 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
317 channels[i].enabled = kchan->enabled;
318 chan_exts[i].discarded_events =
319 discarded_events;
320 chan_exts[i].lost_packets = lost_packets;
321 chan_exts[i].monitor_timer_interval =
322 extended->monitor_timer_interval;
323 chan_exts[i].blocking_timeout = 0;
324 i++;
325 }
326 }
327 break;
328 case LTTNG_DOMAIN_UST:
329 {
330 struct lttng_ht_iter iter;
331 struct ltt_ust_channel *uchan;
332
333 rcu_read_lock();
334 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
335 &iter.iter, uchan, node.node) {
336 uint64_t discarded_events = 0, lost_packets = 0;
337
338 if (lttng_strncpy(channels[i].name, uchan->name,
339 LTTNG_SYMBOL_NAME_LEN)) {
340 break;
341 }
342 channels[i].attr.overwrite = uchan->attr.overwrite;
343 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
344 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
345 channels[i].attr.switch_timer_interval =
346 uchan->attr.switch_timer_interval;
347 channels[i].attr.read_timer_interval =
348 uchan->attr.read_timer_interval;
349 channels[i].enabled = uchan->enabled;
350 channels[i].attr.tracefile_size = uchan->tracefile_size;
351 channels[i].attr.tracefile_count = uchan->tracefile_count;
352
353 /*
354 * Map enum lttng_ust_output to enum lttng_event_output.
355 */
356 switch (uchan->attr.output) {
357 case LTTNG_UST_MMAP:
358 channels[i].attr.output = LTTNG_EVENT_MMAP;
359 break;
360 default:
361 /*
362 * LTTNG_UST_MMAP is the only supported UST
363 * output mode.
364 */
365 assert(0);
366 break;
367 }
368
369 chan_exts[i].monitor_timer_interval =
370 uchan->monitor_timer_interval;
371 chan_exts[i].blocking_timeout =
372 uchan->attr.u.s.blocking_timeout;
373
374 ret = get_ust_runtime_stats(session, uchan,
375 &discarded_events, &lost_packets);
376 if (ret < 0) {
377 break;
378 }
379 chan_exts[i].discarded_events = discarded_events;
380 chan_exts[i].lost_packets = lost_packets;
381 i++;
382 }
383 rcu_read_unlock();
384 break;
385 }
386 default:
387 break;
388 }
389
390 end:
391 if (ret < 0) {
392 return -LTTNG_ERR_FATAL;
393 } else {
394 return LTTNG_OK;
395 }
396 }
397
398 static int increment_extended_len(const char *filter_expression,
399 struct lttng_event_exclusion *exclusion,
400 const struct lttng_userspace_probe_location *probe_location,
401 size_t *extended_len)
402 {
403 int ret = 0;
404
405 *extended_len += sizeof(struct lttcomm_event_extended_header);
406
407 if (filter_expression) {
408 *extended_len += strlen(filter_expression) + 1;
409 }
410
411 if (exclusion) {
412 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
413 }
414
415 if (probe_location) {
416 ret = lttng_userspace_probe_location_serialize(probe_location,
417 NULL, NULL);
418 if (ret < 0) {
419 goto end;
420 }
421 *extended_len += ret;
422 }
423 ret = 0;
424 end:
425 return ret;
426 }
427
428 static int append_extended_info(const char *filter_expression,
429 struct lttng_event_exclusion *exclusion,
430 struct lttng_userspace_probe_location *probe_location,
431 void **extended_at)
432 {
433 int ret = 0;
434 size_t filter_len = 0;
435 size_t nb_exclusions = 0;
436 size_t userspace_probe_location_len = 0;
437 struct lttng_dynamic_buffer location_buffer;
438 struct lttcomm_event_extended_header extended_header;
439
440 if (filter_expression) {
441 filter_len = strlen(filter_expression) + 1;
442 }
443
444 if (exclusion) {
445 nb_exclusions = exclusion->count;
446 }
447
448 if (probe_location) {
449 lttng_dynamic_buffer_init(&location_buffer);
450 ret = lttng_userspace_probe_location_serialize(probe_location,
451 &location_buffer, NULL);
452 if (ret < 0) {
453 ret = -1;
454 goto end;
455 }
456 userspace_probe_location_len = location_buffer.size;
457 }
458
459 /* Set header fields */
460 extended_header.filter_len = filter_len;
461 extended_header.nb_exclusions = nb_exclusions;
462 extended_header.userspace_probe_location_len = userspace_probe_location_len;
463
464 /* Copy header */
465 memcpy(*extended_at, &extended_header, sizeof(extended_header));
466 *extended_at += sizeof(extended_header);
467
468 /* Copy filter string */
469 if (filter_expression) {
470 memcpy(*extended_at, filter_expression, filter_len);
471 *extended_at += filter_len;
472 }
473
474 /* Copy exclusion names */
475 if (exclusion) {
476 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
477
478 memcpy(*extended_at, &exclusion->names, len);
479 *extended_at += len;
480 }
481
482 if (probe_location) {
483 memcpy(*extended_at, location_buffer.data, location_buffer.size);
484 *extended_at += location_buffer.size;
485 lttng_dynamic_buffer_reset(&location_buffer);
486 }
487 ret = 0;
488 end:
489 return ret;
490 }
491
492 /*
493 * Create a list of agent domain events.
494 *
495 * Return number of events in list on success or else a negative value.
496 */
497 static int list_lttng_agent_events(struct agent *agt,
498 struct lttng_event **events, size_t *total_size)
499 {
500 int i = 0, ret = 0;
501 unsigned int nb_event = 0;
502 struct agent_event *event;
503 struct lttng_event *tmp_events = NULL;
504 struct lttng_ht_iter iter;
505 size_t extended_len = 0;
506 void *extended_at;
507
508 assert(agt);
509 assert(events);
510
511 DBG3("Listing agent events");
512
513 rcu_read_lock();
514 nb_event = lttng_ht_get_count(agt->events);
515 rcu_read_unlock();
516 if (nb_event == 0) {
517 ret = nb_event;
518 *total_size = 0;
519 goto error;
520 }
521
522 /* Compute required extended infos size */
523 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
524
525 /*
526 * This is only valid because the commands which add events are
527 * processed in the same thread as the listing.
528 */
529 rcu_read_lock();
530 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
531 ret = increment_extended_len(event->filter_expression, NULL, NULL,
532 &extended_len);
533 if (ret) {
534 DBG("Error computing the length of extended info message");
535 ret = -LTTNG_ERR_FATAL;
536 goto error;
537 }
538 }
539 rcu_read_unlock();
540
541 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
542 tmp_events = zmalloc(*total_size);
543 if (!tmp_events) {
544 PERROR("zmalloc agent events session");
545 ret = -LTTNG_ERR_FATAL;
546 goto error;
547 }
548
549 extended_at = ((uint8_t *) tmp_events) +
550 nb_event * sizeof(struct lttng_event);
551
552 rcu_read_lock();
553 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
554 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
555 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
556 tmp_events[i].enabled = event->enabled;
557 tmp_events[i].loglevel = event->loglevel_value;
558 tmp_events[i].loglevel_type = event->loglevel_type;
559 i++;
560
561 /* Append extended info */
562 ret = append_extended_info(event->filter_expression, NULL, NULL,
563 &extended_at);
564 if (ret) {
565 DBG("Error appending extended info message");
566 ret = -LTTNG_ERR_FATAL;
567 goto error;
568 }
569 }
570
571 *events = tmp_events;
572 ret = nb_event;
573 assert(nb_event == i);
574
575 end:
576 rcu_read_unlock();
577 return ret;
578 error:
579 free(tmp_events);
580 goto end;
581 }
582
583 /*
584 * Create a list of ust global domain events.
585 */
586 static int list_lttng_ust_global_events(char *channel_name,
587 struct ltt_ust_domain_global *ust_global,
588 struct lttng_event **events, size_t *total_size)
589 {
590 int i = 0, ret = 0;
591 unsigned int nb_event = 0;
592 struct lttng_ht_iter iter;
593 struct lttng_ht_node_str *node;
594 struct ltt_ust_channel *uchan;
595 struct ltt_ust_event *uevent;
596 struct lttng_event *tmp;
597 size_t extended_len = 0;
598 void *extended_at;
599
600 DBG("Listing UST global events for channel %s", channel_name);
601
602 rcu_read_lock();
603
604 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
605 node = lttng_ht_iter_get_node_str(&iter);
606 if (node == NULL) {
607 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
608 goto end;
609 }
610
611 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
612
613 nb_event = lttng_ht_get_count(uchan->events);
614 if (nb_event == 0) {
615 ret = nb_event;
616 *total_size = 0;
617 goto end;
618 }
619
620 DBG3("Listing UST global %d events", nb_event);
621
622 /* Compute required extended infos size */
623 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
624 if (uevent->internal) {
625 nb_event--;
626 continue;
627 }
628
629 ret = increment_extended_len(uevent->filter_expression,
630 uevent->exclusion, NULL, &extended_len);
631 if (ret) {
632 DBG("Error computing the length of extended info message");
633 ret = -LTTNG_ERR_FATAL;
634 goto end;
635 }
636 }
637 if (nb_event == 0) {
638 /* All events are internal, skip. */
639 ret = 0;
640 *total_size = 0;
641 goto end;
642 }
643
644 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
645 tmp = zmalloc(*total_size);
646 if (tmp == NULL) {
647 ret = -LTTNG_ERR_FATAL;
648 goto end;
649 }
650
651 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
652
653 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
654 if (uevent->internal) {
655 /* This event should remain hidden from clients */
656 continue;
657 }
658 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
659 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
660 tmp[i].enabled = uevent->enabled;
661
662 switch (uevent->attr.instrumentation) {
663 case LTTNG_UST_TRACEPOINT:
664 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
665 break;
666 case LTTNG_UST_PROBE:
667 tmp[i].type = LTTNG_EVENT_PROBE;
668 break;
669 case LTTNG_UST_FUNCTION:
670 tmp[i].type = LTTNG_EVENT_FUNCTION;
671 break;
672 }
673
674 tmp[i].loglevel = uevent->attr.loglevel;
675 switch (uevent->attr.loglevel_type) {
676 case LTTNG_UST_LOGLEVEL_ALL:
677 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
678 break;
679 case LTTNG_UST_LOGLEVEL_RANGE:
680 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
681 break;
682 case LTTNG_UST_LOGLEVEL_SINGLE:
683 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
684 break;
685 }
686 if (uevent->filter) {
687 tmp[i].filter = 1;
688 }
689 if (uevent->exclusion) {
690 tmp[i].exclusion = 1;
691 }
692 i++;
693
694 /* Append extended info */
695 ret = append_extended_info(uevent->filter_expression,
696 uevent->exclusion, NULL, &extended_at);
697 if (ret) {
698 DBG("Error appending extended info message");
699 ret = -LTTNG_ERR_FATAL;
700 goto end;
701 }
702 }
703
704 ret = nb_event;
705 *events = tmp;
706 end:
707 rcu_read_unlock();
708 return ret;
709 }
710
711 /*
712 * Fill lttng_event array of all kernel events in the channel.
713 */
714 static int list_lttng_kernel_events(char *channel_name,
715 struct ltt_kernel_session *kernel_session,
716 struct lttng_event **events, size_t *total_size)
717 {
718 int i = 0, ret;
719 unsigned int nb_event;
720 struct ltt_kernel_event *event;
721 struct ltt_kernel_channel *kchan;
722 size_t extended_len = 0;
723 void *extended_at;
724
725 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
726 if (kchan == NULL) {
727 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
728 goto error;
729 }
730
731 nb_event = kchan->event_count;
732
733 DBG("Listing events for channel %s", kchan->channel->name);
734
735 if (nb_event == 0) {
736 *total_size = 0;
737 *events = NULL;
738 goto end;
739 }
740
741 /* Compute required extended infos size */
742 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
743 ret = increment_extended_len(event->filter_expression, NULL,
744 event->userspace_probe_location,
745 &extended_len);
746 if (ret) {
747 DBG("Error computing the length of extended info message");
748 ret = -LTTNG_ERR_FATAL;
749 goto error;
750 }
751 }
752
753 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
754 *events = zmalloc(*total_size);
755 if (*events == NULL) {
756 ret = -LTTNG_ERR_FATAL;
757 goto error;
758 }
759
760 extended_at = ((void *) *events) +
761 nb_event * sizeof(struct lttng_event);
762
763 /* Kernel channels */
764 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
765 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
766 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
767 (*events)[i].enabled = event->enabled;
768 (*events)[i].filter =
769 (unsigned char) !!event->filter_expression;
770
771 switch (event->event->instrumentation) {
772 case LTTNG_KERNEL_TRACEPOINT:
773 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
774 break;
775 case LTTNG_KERNEL_KRETPROBE:
776 (*events)[i].type = LTTNG_EVENT_FUNCTION;
777 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
778 sizeof(struct lttng_kernel_kprobe));
779 break;
780 case LTTNG_KERNEL_KPROBE:
781 (*events)[i].type = LTTNG_EVENT_PROBE;
782 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
783 sizeof(struct lttng_kernel_kprobe));
784 break;
785 case LTTNG_KERNEL_UPROBE:
786 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
787 break;
788 case LTTNG_KERNEL_FUNCTION:
789 (*events)[i].type = LTTNG_EVENT_FUNCTION;
790 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
791 sizeof(struct lttng_kernel_function));
792 break;
793 case LTTNG_KERNEL_NOOP:
794 (*events)[i].type = LTTNG_EVENT_NOOP;
795 break;
796 case LTTNG_KERNEL_SYSCALL:
797 (*events)[i].type = LTTNG_EVENT_SYSCALL;
798 break;
799 case LTTNG_KERNEL_ALL:
800 /* fall-through. */
801 default:
802 assert(0);
803 break;
804 }
805 i++;
806
807 /* Append extended info */
808 ret = append_extended_info(event->filter_expression, NULL,
809 event->userspace_probe_location, &extended_at);
810 if (ret) {
811 DBG("Error appending extended info message");
812 ret = -LTTNG_ERR_FATAL;
813 goto error;
814 }
815 }
816
817 end:
818 return nb_event;
819
820 error:
821 /* Negate the error code to differentiate the size from an error */
822 return -ret;
823 }
824
825 /*
826 * Add URI so the consumer output object. Set the correct path depending on the
827 * domain adding the default trace directory.
828 */
829 static enum lttng_error_code add_uri_to_consumer(
830 const struct ltt_session *session,
831 struct consumer_output *consumer,
832 struct lttng_uri *uri, enum lttng_domain_type domain)
833 {
834 int ret;
835 enum lttng_error_code ret_code = LTTNG_OK;
836
837 assert(uri);
838
839 if (consumer == NULL) {
840 DBG("No consumer detected. Don't add URI. Stopping.");
841 ret_code = LTTNG_ERR_NO_CONSUMER;
842 goto error;
843 }
844
845 switch (domain) {
846 case LTTNG_DOMAIN_KERNEL:
847 ret = lttng_strncpy(consumer->domain_subdir,
848 DEFAULT_KERNEL_TRACE_DIR,
849 sizeof(consumer->domain_subdir));
850 break;
851 case LTTNG_DOMAIN_UST:
852 ret = lttng_strncpy(consumer->domain_subdir,
853 DEFAULT_UST_TRACE_DIR,
854 sizeof(consumer->domain_subdir));
855 break;
856 default:
857 /*
858 * This case is possible is we try to add the URI to the global
859 * tracing session consumer object which in this case there is
860 * no subdir.
861 */
862 memset(consumer->domain_subdir, 0,
863 sizeof(consumer->domain_subdir));
864 ret = 0;
865 }
866 if (ret) {
867 ERR("Failed to initialize consumer output domain subdirectory");
868 ret_code = LTTNG_ERR_FATAL;
869 goto error;
870 }
871
872 switch (uri->dtype) {
873 case LTTNG_DST_IPV4:
874 case LTTNG_DST_IPV6:
875 DBG2("Setting network URI to consumer");
876
877 if (consumer->type == CONSUMER_DST_NET) {
878 if ((uri->stype == LTTNG_STREAM_CONTROL &&
879 consumer->dst.net.control_isset) ||
880 (uri->stype == LTTNG_STREAM_DATA &&
881 consumer->dst.net.data_isset)) {
882 ret_code = LTTNG_ERR_URL_EXIST;
883 goto error;
884 }
885 } else {
886 memset(&consumer->dst, 0, sizeof(consumer->dst));
887 }
888
889 /* Set URI into consumer output object */
890 ret = consumer_set_network_uri(session, consumer, uri);
891 if (ret < 0) {
892 ret_code = -ret;
893 goto error;
894 } else if (ret == 1) {
895 /*
896 * URI was the same in the consumer so we do not append the subdir
897 * again so to not duplicate output dir.
898 */
899 ret_code = LTTNG_OK;
900 goto error;
901 }
902 break;
903 case LTTNG_DST_PATH:
904 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
905 ret_code = LTTNG_ERR_INVALID;
906 goto error;
907 }
908 DBG2("Setting trace directory path from URI to %s",
909 uri->dst.path);
910 memset(&consumer->dst, 0, sizeof(consumer->dst));
911
912 ret = lttng_strncpy(consumer->dst.session_root_path,
913 uri->dst.path,
914 sizeof(consumer->dst.session_root_path));
915 consumer->type = CONSUMER_DST_LOCAL;
916 break;
917 }
918
919 ret_code = LTTNG_OK;
920 error:
921 return ret_code;
922 }
923
924 /*
925 * Init tracing by creating trace directory and sending fds kernel consumer.
926 */
927 static int init_kernel_tracing(struct ltt_kernel_session *session)
928 {
929 int ret = 0;
930 struct lttng_ht_iter iter;
931 struct consumer_socket *socket;
932
933 assert(session);
934
935 rcu_read_lock();
936
937 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
938 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
939 socket, node.node) {
940 pthread_mutex_lock(socket->lock);
941 ret = kernel_consumer_send_session(socket, session);
942 pthread_mutex_unlock(socket->lock);
943 if (ret < 0) {
944 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
945 goto error;
946 }
947 }
948 }
949
950 error:
951 rcu_read_unlock();
952 return ret;
953 }
954
955 /*
956 * Create a socket to the relayd using the URI.
957 *
958 * On success, the relayd_sock pointer is set to the created socket.
959 * Else, it remains untouched and an LTTng error code is returned.
960 */
961 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
962 struct lttcomm_relayd_sock **relayd_sock,
963 struct consumer_output *consumer)
964 {
965 int ret;
966 enum lttng_error_code status = LTTNG_OK;
967 struct lttcomm_relayd_sock *rsock;
968
969 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
970 RELAYD_VERSION_COMM_MINOR);
971 if (!rsock) {
972 status = LTTNG_ERR_FATAL;
973 goto error;
974 }
975
976 /*
977 * Connect to relayd so we can proceed with a session creation. This call
978 * can possibly block for an arbitrary amount of time to set the health
979 * state to be in poll execution.
980 */
981 health_poll_entry();
982 ret = relayd_connect(rsock);
983 health_poll_exit();
984 if (ret < 0) {
985 ERR("Unable to reach lttng-relayd");
986 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
987 goto free_sock;
988 }
989
990 /* Create socket for control stream. */
991 if (uri->stype == LTTNG_STREAM_CONTROL) {
992 DBG3("Creating relayd stream socket from URI");
993
994 /* Check relayd version */
995 ret = relayd_version_check(rsock);
996 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
997 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
998 goto close_sock;
999 } else if (ret < 0) {
1000 ERR("Unable to reach lttng-relayd");
1001 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1002 goto close_sock;
1003 }
1004 consumer->relay_major_version = rsock->major;
1005 consumer->relay_minor_version = rsock->minor;
1006 } else if (uri->stype == LTTNG_STREAM_DATA) {
1007 DBG3("Creating relayd data socket from URI");
1008 } else {
1009 /* Command is not valid */
1010 ERR("Relayd invalid stream type: %d", uri->stype);
1011 status = LTTNG_ERR_INVALID;
1012 goto close_sock;
1013 }
1014
1015 *relayd_sock = rsock;
1016
1017 return status;
1018
1019 close_sock:
1020 /* The returned value is not useful since we are on an error path. */
1021 (void) relayd_close(rsock);
1022 free_sock:
1023 free(rsock);
1024 error:
1025 return status;
1026 }
1027
1028 /*
1029 * Connect to the relayd using URI and send the socket to the right consumer.
1030 *
1031 * The consumer socket lock must be held by the caller.
1032 *
1033 * Returns LTTNG_OK on success or an LTTng error code on failure.
1034 */
1035 static enum lttng_error_code send_consumer_relayd_socket(
1036 unsigned int session_id,
1037 struct lttng_uri *relayd_uri,
1038 struct consumer_output *consumer,
1039 struct consumer_socket *consumer_sock,
1040 const char *session_name, const char *hostname,
1041 const char *base_path, int session_live_timer,
1042 const uint64_t *current_chunk_id,
1043 time_t session_creation_time,
1044 bool session_name_contains_creation_time)
1045 {
1046 int ret;
1047 struct lttcomm_relayd_sock *rsock = NULL;
1048 enum lttng_error_code status;
1049
1050 /* Connect to relayd and make version check if uri is the control. */
1051 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1052 if (status != LTTNG_OK) {
1053 goto relayd_comm_error;
1054 }
1055 assert(rsock);
1056
1057 /* Set the network sequence index if not set. */
1058 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1059 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1060 /*
1061 * Increment net_seq_idx because we are about to transfer the
1062 * new relayd socket to the consumer.
1063 * Assign unique key so the consumer can match streams.
1064 */
1065 consumer->net_seq_index = ++relayd_net_seq_idx;
1066 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1067 }
1068
1069 /* Send relayd socket to consumer. */
1070 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1071 relayd_uri->stype, session_id,
1072 session_name, hostname, base_path,
1073 session_live_timer, current_chunk_id,
1074 session_creation_time, session_name_contains_creation_time);
1075 if (ret < 0) {
1076 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1077 goto close_sock;
1078 }
1079
1080 /* Flag that the corresponding socket was sent. */
1081 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1082 consumer_sock->control_sock_sent = 1;
1083 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1084 consumer_sock->data_sock_sent = 1;
1085 }
1086
1087 /*
1088 * Close socket which was dup on the consumer side. The session daemon does
1089 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1090 */
1091
1092 close_sock:
1093 if (status != LTTNG_OK) {
1094 /*
1095 * The consumer output for this session should not be used anymore
1096 * since the relayd connection failed thus making any tracing or/and
1097 * streaming not usable.
1098 */
1099 consumer->enabled = 0;
1100 }
1101 (void) relayd_close(rsock);
1102 free(rsock);
1103
1104 relayd_comm_error:
1105 return status;
1106 }
1107
1108 /*
1109 * Send both relayd sockets to a specific consumer and domain. This is a
1110 * helper function to facilitate sending the information to the consumer for a
1111 * session.
1112 *
1113 * The consumer socket lock must be held by the caller.
1114 *
1115 * Returns LTTNG_OK, or an LTTng error code on failure.
1116 */
1117 static enum lttng_error_code send_consumer_relayd_sockets(
1118 enum lttng_domain_type domain,
1119 unsigned int session_id, struct consumer_output *consumer,
1120 struct consumer_socket *sock, const char *session_name,
1121 const char *hostname, const char *base_path, int session_live_timer,
1122 const uint64_t *current_chunk_id, time_t session_creation_time,
1123 bool session_name_contains_creation_time)
1124 {
1125 enum lttng_error_code status = LTTNG_OK;
1126
1127 assert(consumer);
1128 assert(sock);
1129
1130 /* Sending control relayd socket. */
1131 if (!sock->control_sock_sent) {
1132 status = send_consumer_relayd_socket(session_id,
1133 &consumer->dst.net.control, consumer, sock,
1134 session_name, hostname, base_path, session_live_timer,
1135 current_chunk_id, session_creation_time,
1136 session_name_contains_creation_time);
1137 if (status != LTTNG_OK) {
1138 goto error;
1139 }
1140 }
1141
1142 /* Sending data relayd socket. */
1143 if (!sock->data_sock_sent) {
1144 status = send_consumer_relayd_socket(session_id,
1145 &consumer->dst.net.data, consumer, sock,
1146 session_name, hostname, base_path, session_live_timer,
1147 current_chunk_id, session_creation_time,
1148 session_name_contains_creation_time);
1149 if (status != LTTNG_OK) {
1150 goto error;
1151 }
1152 }
1153
1154 error:
1155 return status;
1156 }
1157
1158 /*
1159 * Setup relayd connections for a tracing session. First creates the socket to
1160 * the relayd and send them to the right domain consumer. Consumer type MUST be
1161 * network.
1162 */
1163 int cmd_setup_relayd(struct ltt_session *session)
1164 {
1165 int ret = LTTNG_OK;
1166 struct ltt_ust_session *usess;
1167 struct ltt_kernel_session *ksess;
1168 struct consumer_socket *socket;
1169 struct lttng_ht_iter iter;
1170 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1171
1172 assert(session);
1173
1174 usess = session->ust_session;
1175 ksess = session->kernel_session;
1176
1177 DBG("Setting relayd for session %s", session->name);
1178
1179 if (session->current_trace_chunk) {
1180 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1181 session->current_trace_chunk, &current_chunk_id.value);
1182
1183 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1184 current_chunk_id.is_set = true;
1185 } else {
1186 ERR("Failed to get current trace chunk id");
1187 ret = LTTNG_ERR_UNK;
1188 goto error;
1189 }
1190 }
1191
1192 rcu_read_lock();
1193
1194 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1195 && usess->consumer->enabled) {
1196 /* For each consumer socket, send relayd sockets */
1197 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1198 socket, node.node) {
1199 pthread_mutex_lock(socket->lock);
1200 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1201 usess->consumer, socket,
1202 session->name, session->hostname,
1203 session->base_path,
1204 session->live_timer,
1205 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1206 session->creation_time,
1207 session->name_contains_creation_time);
1208 pthread_mutex_unlock(socket->lock);
1209 if (ret != LTTNG_OK) {
1210 goto error;
1211 }
1212 /* Session is now ready for network streaming. */
1213 session->net_handle = 1;
1214 }
1215 session->consumer->relay_major_version =
1216 usess->consumer->relay_major_version;
1217 session->consumer->relay_minor_version =
1218 usess->consumer->relay_minor_version;
1219 }
1220
1221 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1222 && ksess->consumer->enabled) {
1223 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1224 socket, node.node) {
1225 pthread_mutex_lock(socket->lock);
1226 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1227 ksess->consumer, socket,
1228 session->name, session->hostname,
1229 session->base_path,
1230 session->live_timer,
1231 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1232 session->creation_time,
1233 session->name_contains_creation_time);
1234 pthread_mutex_unlock(socket->lock);
1235 if (ret != LTTNG_OK) {
1236 goto error;
1237 }
1238 /* Session is now ready for network streaming. */
1239 session->net_handle = 1;
1240 }
1241 session->consumer->relay_major_version =
1242 ksess->consumer->relay_major_version;
1243 session->consumer->relay_minor_version =
1244 ksess->consumer->relay_minor_version;
1245 }
1246
1247 error:
1248 rcu_read_unlock();
1249 return ret;
1250 }
1251
1252 /*
1253 * Start a kernel session by opening all necessary streams.
1254 */
1255 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1256 {
1257 int ret;
1258 struct ltt_kernel_channel *kchan;
1259
1260 /* Open kernel metadata */
1261 if (ksess->metadata == NULL && ksess->output_traces) {
1262 ret = kernel_open_metadata(ksess);
1263 if (ret < 0) {
1264 ret = LTTNG_ERR_KERN_META_FAIL;
1265 goto error;
1266 }
1267 }
1268
1269 /* Open kernel metadata stream */
1270 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1271 ret = kernel_open_metadata_stream(ksess);
1272 if (ret < 0) {
1273 ERR("Kernel create metadata stream failed");
1274 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1275 goto error;
1276 }
1277 }
1278
1279 /* For each channel */
1280 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1281 if (kchan->stream_count == 0) {
1282 ret = kernel_open_channel_stream(kchan);
1283 if (ret < 0) {
1284 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1285 goto error;
1286 }
1287 /* Update the stream global counter */
1288 ksess->stream_count_global += ret;
1289 }
1290 }
1291
1292 /* Setup kernel consumer socket and send fds to it */
1293 ret = init_kernel_tracing(ksess);
1294 if (ret != 0) {
1295 ret = LTTNG_ERR_KERN_START_FAIL;
1296 goto error;
1297 }
1298
1299 /* This start the kernel tracing */
1300 ret = kernel_start_session(ksess);
1301 if (ret < 0) {
1302 ret = LTTNG_ERR_KERN_START_FAIL;
1303 goto error;
1304 }
1305
1306 /* Quiescent wait after starting trace */
1307 kernel_wait_quiescent(wpipe);
1308
1309 ksess->active = 1;
1310
1311 ret = LTTNG_OK;
1312
1313 error:
1314 return ret;
1315 }
1316
1317 /*
1318 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1319 */
1320 int cmd_disable_channel(struct ltt_session *session,
1321 enum lttng_domain_type domain, char *channel_name)
1322 {
1323 int ret;
1324 struct ltt_ust_session *usess;
1325
1326 usess = session->ust_session;
1327
1328 rcu_read_lock();
1329
1330 switch (domain) {
1331 case LTTNG_DOMAIN_KERNEL:
1332 {
1333 ret = channel_kernel_disable(session->kernel_session,
1334 channel_name);
1335 if (ret != LTTNG_OK) {
1336 goto error;
1337 }
1338
1339 kernel_wait_quiescent(kernel_tracer_fd);
1340 break;
1341 }
1342 case LTTNG_DOMAIN_UST:
1343 {
1344 struct ltt_ust_channel *uchan;
1345 struct lttng_ht *chan_ht;
1346
1347 chan_ht = usess->domain_global.channels;
1348
1349 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1350 if (uchan == NULL) {
1351 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1352 goto error;
1353 }
1354
1355 ret = channel_ust_disable(usess, uchan);
1356 if (ret != LTTNG_OK) {
1357 goto error;
1358 }
1359 break;
1360 }
1361 default:
1362 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1363 goto error;
1364 }
1365
1366 ret = LTTNG_OK;
1367
1368 error:
1369 rcu_read_unlock();
1370 return ret;
1371 }
1372
1373 /*
1374 * Command LTTNG_TRACK_PID processed by the client thread.
1375 *
1376 * Called with session lock held.
1377 */
1378 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1379 int pid)
1380 {
1381 int ret;
1382
1383 rcu_read_lock();
1384
1385 switch (domain) {
1386 case LTTNG_DOMAIN_KERNEL:
1387 {
1388 struct ltt_kernel_session *ksess;
1389
1390 ksess = session->kernel_session;
1391
1392 ret = kernel_track_pid(ksess, pid);
1393 if (ret != LTTNG_OK) {
1394 goto error;
1395 }
1396
1397 kernel_wait_quiescent(kernel_tracer_fd);
1398 break;
1399 }
1400 case LTTNG_DOMAIN_UST:
1401 {
1402 struct ltt_ust_session *usess;
1403
1404 usess = session->ust_session;
1405
1406 ret = trace_ust_track_pid(usess, pid);
1407 if (ret != LTTNG_OK) {
1408 goto error;
1409 }
1410 break;
1411 }
1412 default:
1413 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1414 goto error;
1415 }
1416
1417 ret = LTTNG_OK;
1418
1419 error:
1420 rcu_read_unlock();
1421 return ret;
1422 }
1423
1424 /*
1425 * Command LTTNG_UNTRACK_PID processed by the client thread.
1426 *
1427 * Called with session lock held.
1428 */
1429 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1430 int pid)
1431 {
1432 int ret;
1433
1434 rcu_read_lock();
1435
1436 switch (domain) {
1437 case LTTNG_DOMAIN_KERNEL:
1438 {
1439 struct ltt_kernel_session *ksess;
1440
1441 ksess = session->kernel_session;
1442
1443 ret = kernel_untrack_pid(ksess, pid);
1444 if (ret != LTTNG_OK) {
1445 goto error;
1446 }
1447
1448 kernel_wait_quiescent(kernel_tracer_fd);
1449 break;
1450 }
1451 case LTTNG_DOMAIN_UST:
1452 {
1453 struct ltt_ust_session *usess;
1454
1455 usess = session->ust_session;
1456
1457 ret = trace_ust_untrack_pid(usess, pid);
1458 if (ret != LTTNG_OK) {
1459 goto error;
1460 }
1461 break;
1462 }
1463 default:
1464 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1465 goto error;
1466 }
1467
1468 ret = LTTNG_OK;
1469
1470 error:
1471 rcu_read_unlock();
1472 return ret;
1473 }
1474
1475 /*
1476 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1477 *
1478 * The wpipe arguments is used as a notifier for the kernel thread.
1479 */
1480 int cmd_enable_channel(struct ltt_session *session,
1481 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1482 {
1483 int ret;
1484 struct ltt_ust_session *usess = session->ust_session;
1485 struct lttng_ht *chan_ht;
1486 size_t len;
1487
1488 assert(session);
1489 assert(attr);
1490 assert(domain);
1491
1492 len = lttng_strnlen(attr->name, sizeof(attr->name));
1493
1494 /* Validate channel name */
1495 if (attr->name[0] == '.' ||
1496 memchr(attr->name, '/', len) != NULL) {
1497 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1498 goto end;
1499 }
1500
1501 DBG("Enabling channel %s for session %s", attr->name, session->name);
1502
1503 rcu_read_lock();
1504
1505 /*
1506 * Don't try to enable a channel if the session has been started at
1507 * some point in time before. The tracer does not allow it.
1508 */
1509 if (session->has_been_started) {
1510 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1511 goto error;
1512 }
1513
1514 /*
1515 * If the session is a live session, remove the switch timer, the
1516 * live timer does the same thing but sends also synchronisation
1517 * beacons for inactive streams.
1518 */
1519 if (session->live_timer > 0) {
1520 attr->attr.live_timer_interval = session->live_timer;
1521 attr->attr.switch_timer_interval = 0;
1522 }
1523
1524 /* Check for feature support */
1525 switch (domain->type) {
1526 case LTTNG_DOMAIN_KERNEL:
1527 {
1528 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1529 /* Sampling position of buffer is not supported */
1530 WARN("Kernel tracer does not support buffer monitoring. "
1531 "Setting the monitor interval timer to 0 "
1532 "(disabled) for channel '%s' of session '%s'",
1533 attr-> name, session->name);
1534 lttng_channel_set_monitor_timer_interval(attr, 0);
1535 }
1536 break;
1537 }
1538 case LTTNG_DOMAIN_UST:
1539 break;
1540 case LTTNG_DOMAIN_JUL:
1541 case LTTNG_DOMAIN_LOG4J:
1542 case LTTNG_DOMAIN_PYTHON:
1543 if (!agent_tracing_is_enabled()) {
1544 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1545 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1546 goto error;
1547 }
1548 break;
1549 default:
1550 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1551 goto error;
1552 }
1553
1554 switch (domain->type) {
1555 case LTTNG_DOMAIN_KERNEL:
1556 {
1557 struct ltt_kernel_channel *kchan;
1558
1559 kchan = trace_kernel_get_channel_by_name(attr->name,
1560 session->kernel_session);
1561 if (kchan == NULL) {
1562 if (session->snapshot.nb_output > 0 ||
1563 session->snapshot_mode) {
1564 /* Enforce mmap output for snapshot sessions. */
1565 attr->attr.output = LTTNG_EVENT_MMAP;
1566 }
1567 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1568 if (attr->name[0] != '\0') {
1569 session->kernel_session->has_non_default_channel = 1;
1570 }
1571 } else {
1572 ret = channel_kernel_enable(session->kernel_session, kchan);
1573 }
1574
1575 if (ret != LTTNG_OK) {
1576 goto error;
1577 }
1578
1579 kernel_wait_quiescent(kernel_tracer_fd);
1580 break;
1581 }
1582 case LTTNG_DOMAIN_UST:
1583 case LTTNG_DOMAIN_JUL:
1584 case LTTNG_DOMAIN_LOG4J:
1585 case LTTNG_DOMAIN_PYTHON:
1586 {
1587 struct ltt_ust_channel *uchan;
1588
1589 /*
1590 * FIXME
1591 *
1592 * Current agent implementation limitations force us to allow
1593 * only one channel at once in "agent" subdomains. Each
1594 * subdomain has a default channel name which must be strictly
1595 * adhered to.
1596 */
1597 if (domain->type == LTTNG_DOMAIN_JUL) {
1598 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1599 LTTNG_SYMBOL_NAME_LEN)) {
1600 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1601 goto error;
1602 }
1603 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1604 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1605 LTTNG_SYMBOL_NAME_LEN)) {
1606 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1607 goto error;
1608 }
1609 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1610 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1611 LTTNG_SYMBOL_NAME_LEN)) {
1612 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1613 goto error;
1614 }
1615 }
1616
1617 chan_ht = usess->domain_global.channels;
1618
1619 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1620 if (uchan == NULL) {
1621 ret = channel_ust_create(usess, attr, domain->buf_type);
1622 if (attr->name[0] != '\0') {
1623 usess->has_non_default_channel = 1;
1624 }
1625 } else {
1626 ret = channel_ust_enable(usess, uchan);
1627 }
1628 break;
1629 }
1630 default:
1631 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1632 goto error;
1633 }
1634
1635 if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1636 session->has_non_mmap_channel = true;
1637 }
1638 error:
1639 rcu_read_unlock();
1640 end:
1641 return ret;
1642 }
1643
1644 /*
1645 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1646 */
1647 int cmd_disable_event(struct ltt_session *session,
1648 enum lttng_domain_type domain, char *channel_name,
1649 struct lttng_event *event)
1650 {
1651 int ret;
1652 char *event_name;
1653
1654 DBG("Disable event command for event \'%s\'", event->name);
1655
1656 event_name = event->name;
1657
1658 /* Error out on unhandled search criteria */
1659 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1660 || event->pid || event->filter || event->exclusion) {
1661 ret = LTTNG_ERR_UNK;
1662 goto error;
1663 }
1664
1665 rcu_read_lock();
1666
1667 switch (domain) {
1668 case LTTNG_DOMAIN_KERNEL:
1669 {
1670 struct ltt_kernel_channel *kchan;
1671 struct ltt_kernel_session *ksess;
1672
1673 ksess = session->kernel_session;
1674
1675 /*
1676 * If a non-default channel has been created in the
1677 * session, explicitely require that -c chan_name needs
1678 * to be provided.
1679 */
1680 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1681 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1682 goto error_unlock;
1683 }
1684
1685 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1686 if (kchan == NULL) {
1687 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1688 goto error_unlock;
1689 }
1690
1691 switch (event->type) {
1692 case LTTNG_EVENT_ALL:
1693 case LTTNG_EVENT_TRACEPOINT:
1694 case LTTNG_EVENT_SYSCALL:
1695 case LTTNG_EVENT_PROBE:
1696 case LTTNG_EVENT_FUNCTION:
1697 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1698 if (event_name[0] == '\0') {
1699 ret = event_kernel_disable_event(kchan,
1700 NULL, event->type);
1701 } else {
1702 ret = event_kernel_disable_event(kchan,
1703 event_name, event->type);
1704 }
1705 if (ret != LTTNG_OK) {
1706 goto error_unlock;
1707 }
1708 break;
1709 default:
1710 ret = LTTNG_ERR_UNK;
1711 goto error_unlock;
1712 }
1713
1714 kernel_wait_quiescent(kernel_tracer_fd);
1715 break;
1716 }
1717 case LTTNG_DOMAIN_UST:
1718 {
1719 struct ltt_ust_channel *uchan;
1720 struct ltt_ust_session *usess;
1721
1722 usess = session->ust_session;
1723
1724 if (validate_ust_event_name(event_name)) {
1725 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1726 goto error_unlock;
1727 }
1728
1729 /*
1730 * If a non-default channel has been created in the
1731 * session, explicitly require that -c chan_name needs
1732 * to be provided.
1733 */
1734 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1735 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1736 goto error_unlock;
1737 }
1738
1739 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1740 channel_name);
1741 if (uchan == NULL) {
1742 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1743 goto error_unlock;
1744 }
1745
1746 switch (event->type) {
1747 case LTTNG_EVENT_ALL:
1748 /*
1749 * An empty event name means that everything
1750 * should be disabled.
1751 */
1752 if (event->name[0] == '\0') {
1753 ret = event_ust_disable_all_tracepoints(usess, uchan);
1754 } else {
1755 ret = event_ust_disable_tracepoint(usess, uchan,
1756 event_name);
1757 }
1758 if (ret != LTTNG_OK) {
1759 goto error_unlock;
1760 }
1761 break;
1762 default:
1763 ret = LTTNG_ERR_UNK;
1764 goto error_unlock;
1765 }
1766
1767 DBG3("Disable UST event %s in channel %s completed", event_name,
1768 channel_name);
1769 break;
1770 }
1771 case LTTNG_DOMAIN_LOG4J:
1772 case LTTNG_DOMAIN_JUL:
1773 case LTTNG_DOMAIN_PYTHON:
1774 {
1775 struct agent *agt;
1776 struct ltt_ust_session *usess = session->ust_session;
1777
1778 assert(usess);
1779
1780 switch (event->type) {
1781 case LTTNG_EVENT_ALL:
1782 break;
1783 default:
1784 ret = LTTNG_ERR_UNK;
1785 goto error_unlock;
1786 }
1787
1788 agt = trace_ust_find_agent(usess, domain);
1789 if (!agt) {
1790 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1791 goto error_unlock;
1792 }
1793 /*
1794 * An empty event name means that everything
1795 * should be disabled.
1796 */
1797 if (event->name[0] == '\0') {
1798 ret = event_agent_disable_all(usess, agt);
1799 } else {
1800 ret = event_agent_disable(usess, agt, event_name);
1801 }
1802 if (ret != LTTNG_OK) {
1803 goto error_unlock;
1804 }
1805
1806 break;
1807 }
1808 default:
1809 ret = LTTNG_ERR_UND;
1810 goto error_unlock;
1811 }
1812
1813 ret = LTTNG_OK;
1814
1815 error_unlock:
1816 rcu_read_unlock();
1817 error:
1818 return ret;
1819 }
1820
1821 /*
1822 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1823 */
1824 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1825 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1826 {
1827 int ret, chan_kern_created = 0, chan_ust_created = 0;
1828 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1829
1830 /*
1831 * Don't try to add a context if the session has been started at
1832 * some point in time before. The tracer does not allow it and would
1833 * result in a corrupted trace.
1834 */
1835 if (session->has_been_started) {
1836 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1837 goto end;
1838 }
1839
1840 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1841 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1842 app_ctx_name = ctx->u.app_ctx.ctx_name;
1843 }
1844
1845 switch (domain) {
1846 case LTTNG_DOMAIN_KERNEL:
1847 assert(session->kernel_session);
1848
1849 if (session->kernel_session->channel_count == 0) {
1850 /* Create default channel */
1851 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1852 if (ret != LTTNG_OK) {
1853 goto error;
1854 }
1855 chan_kern_created = 1;
1856 }
1857 /* Add kernel context to kernel tracer */
1858 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1859 if (ret != LTTNG_OK) {
1860 goto error;
1861 }
1862 break;
1863 case LTTNG_DOMAIN_JUL:
1864 case LTTNG_DOMAIN_LOG4J:
1865 {
1866 /*
1867 * Validate channel name.
1868 * If no channel name is given and the domain is JUL or LOG4J,
1869 * set it to the appropriate domain-specific channel name. If
1870 * a name is provided but does not match the expexted channel
1871 * name, return an error.
1872 */
1873 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1874 strcmp(channel_name,
1875 DEFAULT_JUL_CHANNEL_NAME)) {
1876 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1877 goto error;
1878 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1879 strcmp(channel_name,
1880 DEFAULT_LOG4J_CHANNEL_NAME)) {
1881 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1882 goto error;
1883 }
1884 /* break is _not_ missing here. */
1885 }
1886 case LTTNG_DOMAIN_UST:
1887 {
1888 struct ltt_ust_session *usess = session->ust_session;
1889 unsigned int chan_count;
1890
1891 assert(usess);
1892
1893 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1894 if (chan_count == 0) {
1895 struct lttng_channel *attr;
1896 /* Create default channel */
1897 attr = channel_new_default_attr(domain, usess->buffer_type);
1898 if (attr == NULL) {
1899 ret = LTTNG_ERR_FATAL;
1900 goto error;
1901 }
1902
1903 ret = channel_ust_create(usess, attr, usess->buffer_type);
1904 if (ret != LTTNG_OK) {
1905 free(attr);
1906 goto error;
1907 }
1908 channel_attr_destroy(attr);
1909 chan_ust_created = 1;
1910 }
1911
1912 ret = context_ust_add(usess, domain, ctx, channel_name);
1913 free(app_ctx_provider_name);
1914 free(app_ctx_name);
1915 app_ctx_name = NULL;
1916 app_ctx_provider_name = NULL;
1917 if (ret != LTTNG_OK) {
1918 goto error;
1919 }
1920 break;
1921 }
1922 default:
1923 ret = LTTNG_ERR_UND;
1924 goto error;
1925 }
1926
1927 ret = LTTNG_OK;
1928 goto end;
1929
1930 error:
1931 if (chan_kern_created) {
1932 struct ltt_kernel_channel *kchan =
1933 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1934 session->kernel_session);
1935 /* Created previously, this should NOT fail. */
1936 assert(kchan);
1937 kernel_destroy_channel(kchan);
1938 }
1939
1940 if (chan_ust_created) {
1941 struct ltt_ust_channel *uchan =
1942 trace_ust_find_channel_by_name(
1943 session->ust_session->domain_global.channels,
1944 DEFAULT_CHANNEL_NAME);
1945 /* Created previously, this should NOT fail. */
1946 assert(uchan);
1947 /* Remove from the channel list of the session. */
1948 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1949 uchan);
1950 trace_ust_destroy_channel(uchan);
1951 }
1952 end:
1953 free(app_ctx_provider_name);
1954 free(app_ctx_name);
1955 return ret;
1956 }
1957
1958 static inline bool name_starts_with(const char *name, const char *prefix)
1959 {
1960 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1961
1962 return !strncmp(name, prefix, max_cmp_len);
1963 }
1964
1965 /* Perform userspace-specific event name validation */
1966 static int validate_ust_event_name(const char *name)
1967 {
1968 int ret = 0;
1969
1970 if (!name) {
1971 ret = -1;
1972 goto end;
1973 }
1974
1975 /*
1976 * Check name against all internal UST event component namespaces used
1977 * by the agents.
1978 */
1979 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1980 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1981 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1982 ret = -1;
1983 }
1984
1985 end:
1986 return ret;
1987 }
1988
1989 /*
1990 * Internal version of cmd_enable_event() with a supplemental
1991 * "internal_event" flag which is used to enable internal events which should
1992 * be hidden from clients. Such events are used in the agent implementation to
1993 * enable the events through which all "agent" events are funeled.
1994 */
1995 static int _cmd_enable_event(struct ltt_session *session,
1996 struct lttng_domain *domain,
1997 char *channel_name, struct lttng_event *event,
1998 char *filter_expression,
1999 struct lttng_filter_bytecode *filter,
2000 struct lttng_event_exclusion *exclusion,
2001 int wpipe, bool internal_event)
2002 {
2003 int ret = 0, channel_created = 0;
2004 struct lttng_channel *attr = NULL;
2005
2006 assert(session);
2007 assert(event);
2008 assert(channel_name);
2009
2010 /* If we have a filter, we must have its filter expression */
2011 assert(!(!!filter_expression ^ !!filter));
2012
2013 /* Normalize event name as a globbing pattern */
2014 strutils_normalize_star_glob_pattern(event->name);
2015
2016 /* Normalize exclusion names as globbing patterns */
2017 if (exclusion) {
2018 size_t i;
2019
2020 for (i = 0; i < exclusion->count; i++) {
2021 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2022
2023 strutils_normalize_star_glob_pattern(name);
2024 }
2025 }
2026
2027 DBG("Enable event command for event \'%s\'", event->name);
2028
2029 rcu_read_lock();
2030
2031 switch (domain->type) {
2032 case LTTNG_DOMAIN_KERNEL:
2033 {
2034 struct ltt_kernel_channel *kchan;
2035
2036 /*
2037 * If a non-default channel has been created in the
2038 * session, explicitely require that -c chan_name needs
2039 * to be provided.
2040 */
2041 if (session->kernel_session->has_non_default_channel
2042 && channel_name[0] == '\0') {
2043 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2044 goto error;
2045 }
2046
2047 kchan = trace_kernel_get_channel_by_name(channel_name,
2048 session->kernel_session);
2049 if (kchan == NULL) {
2050 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2051 LTTNG_BUFFER_GLOBAL);
2052 if (attr == NULL) {
2053 ret = LTTNG_ERR_FATAL;
2054 goto error;
2055 }
2056 if (lttng_strncpy(attr->name, channel_name,
2057 sizeof(attr->name))) {
2058 ret = LTTNG_ERR_INVALID;
2059 goto error;
2060 }
2061
2062 ret = cmd_enable_channel(session, domain, attr, wpipe);
2063 if (ret != LTTNG_OK) {
2064 goto error;
2065 }
2066 channel_created = 1;
2067 }
2068
2069 /* Get the newly created kernel channel pointer */
2070 kchan = trace_kernel_get_channel_by_name(channel_name,
2071 session->kernel_session);
2072 if (kchan == NULL) {
2073 /* This sould not happen... */
2074 ret = LTTNG_ERR_FATAL;
2075 goto error;
2076 }
2077
2078 switch (event->type) {
2079 case LTTNG_EVENT_ALL:
2080 {
2081 char *filter_expression_a = NULL;
2082 struct lttng_filter_bytecode *filter_a = NULL;
2083
2084 /*
2085 * We need to duplicate filter_expression and filter,
2086 * because ownership is passed to first enable
2087 * event.
2088 */
2089 if (filter_expression) {
2090 filter_expression_a = strdup(filter_expression);
2091 if (!filter_expression_a) {
2092 ret = LTTNG_ERR_FATAL;
2093 goto error;
2094 }
2095 }
2096 if (filter) {
2097 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2098 if (!filter_a) {
2099 free(filter_expression_a);
2100 ret = LTTNG_ERR_FATAL;
2101 goto error;
2102 }
2103 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2104 }
2105 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2106 ret = event_kernel_enable_event(kchan, event,
2107 filter_expression, filter);
2108 /* We have passed ownership */
2109 filter_expression = NULL;
2110 filter = NULL;
2111 if (ret != LTTNG_OK) {
2112 if (channel_created) {
2113 /* Let's not leak a useless channel. */
2114 kernel_destroy_channel(kchan);
2115 }
2116 free(filter_expression_a);
2117 free(filter_a);
2118 goto error;
2119 }
2120 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2121 ret = event_kernel_enable_event(kchan, event,
2122 filter_expression_a, filter_a);
2123 /* We have passed ownership */
2124 filter_expression_a = NULL;
2125 filter_a = NULL;
2126 if (ret != LTTNG_OK) {
2127 goto error;
2128 }
2129 break;
2130 }
2131 case LTTNG_EVENT_PROBE:
2132 case LTTNG_EVENT_USERSPACE_PROBE:
2133 case LTTNG_EVENT_FUNCTION:
2134 case LTTNG_EVENT_FUNCTION_ENTRY:
2135 case LTTNG_EVENT_TRACEPOINT:
2136 ret = event_kernel_enable_event(kchan, event,
2137 filter_expression, filter);
2138 /* We have passed ownership */
2139 filter_expression = NULL;
2140 filter = NULL;
2141 if (ret != LTTNG_OK) {
2142 if (channel_created) {
2143 /* Let's not leak a useless channel. */
2144 kernel_destroy_channel(kchan);
2145 }
2146 goto error;
2147 }
2148 break;
2149 case LTTNG_EVENT_SYSCALL:
2150 ret = event_kernel_enable_event(kchan, event,
2151 filter_expression, filter);
2152 /* We have passed ownership */
2153 filter_expression = NULL;
2154 filter = NULL;
2155 if (ret != LTTNG_OK) {
2156 goto error;
2157 }
2158 break;
2159 default:
2160 ret = LTTNG_ERR_UNK;
2161 goto error;
2162 }
2163
2164 kernel_wait_quiescent(kernel_tracer_fd);
2165 break;
2166 }
2167 case LTTNG_DOMAIN_UST:
2168 {
2169 struct ltt_ust_channel *uchan;
2170 struct ltt_ust_session *usess = session->ust_session;
2171
2172 assert(usess);
2173
2174 /*
2175 * If a non-default channel has been created in the
2176 * session, explicitely require that -c chan_name needs
2177 * to be provided.
2178 */
2179 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2180 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2181 goto error;
2182 }
2183
2184 /* Get channel from global UST domain */
2185 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2186 channel_name);
2187 if (uchan == NULL) {
2188 /* Create default channel */
2189 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2190 usess->buffer_type);
2191 if (attr == NULL) {
2192 ret = LTTNG_ERR_FATAL;
2193 goto error;
2194 }
2195 if (lttng_strncpy(attr->name, channel_name,
2196 sizeof(attr->name))) {
2197 ret = LTTNG_ERR_INVALID;
2198 goto error;
2199 }
2200
2201 ret = cmd_enable_channel(session, domain, attr, wpipe);
2202 if (ret != LTTNG_OK) {
2203 goto error;
2204 }
2205
2206 /* Get the newly created channel reference back */
2207 uchan = trace_ust_find_channel_by_name(
2208 usess->domain_global.channels, channel_name);
2209 assert(uchan);
2210 }
2211
2212 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2213 /*
2214 * Don't allow users to add UST events to channels which
2215 * are assigned to a userspace subdomain (JUL, Log4J,
2216 * Python, etc.).
2217 */
2218 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2219 goto error;
2220 }
2221
2222 if (!internal_event) {
2223 /*
2224 * Ensure the event name is not reserved for internal
2225 * use.
2226 */
2227 ret = validate_ust_event_name(event->name);
2228 if (ret) {
2229 WARN("Userspace event name %s failed validation.",
2230 event->name);
2231 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2232 goto error;
2233 }
2234 }
2235
2236 /* At this point, the session and channel exist on the tracer */
2237 ret = event_ust_enable_tracepoint(usess, uchan, event,
2238 filter_expression, filter, exclusion,
2239 internal_event);
2240 /* We have passed ownership */
2241 filter_expression = NULL;
2242 filter = NULL;
2243 exclusion = NULL;
2244 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2245 goto already_enabled;
2246 } else if (ret != LTTNG_OK) {
2247 goto error;
2248 }
2249 break;
2250 }
2251 case LTTNG_DOMAIN_LOG4J:
2252 case LTTNG_DOMAIN_JUL:
2253 case LTTNG_DOMAIN_PYTHON:
2254 {
2255 const char *default_event_name, *default_chan_name;
2256 struct agent *agt;
2257 struct lttng_event uevent;
2258 struct lttng_domain tmp_dom;
2259 struct ltt_ust_session *usess = session->ust_session;
2260
2261 assert(usess);
2262
2263 if (!agent_tracing_is_enabled()) {
2264 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2265 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2266 goto error;
2267 }
2268
2269 agt = trace_ust_find_agent(usess, domain->type);
2270 if (!agt) {
2271 agt = agent_create(domain->type);
2272 if (!agt) {
2273 ret = LTTNG_ERR_NOMEM;
2274 goto error;
2275 }
2276 agent_add(agt, usess->agents);
2277 }
2278
2279 /* Create the default tracepoint. */
2280 memset(&uevent, 0, sizeof(uevent));
2281 uevent.type = LTTNG_EVENT_TRACEPOINT;
2282 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2283 default_event_name = event_get_default_agent_ust_name(
2284 domain->type);
2285 if (!default_event_name) {
2286 ret = LTTNG_ERR_FATAL;
2287 goto error;
2288 }
2289 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2290 uevent.name[sizeof(uevent.name) - 1] = '\0';
2291
2292 /*
2293 * The domain type is changed because we are about to enable the
2294 * default channel and event for the JUL domain that are hardcoded.
2295 * This happens in the UST domain.
2296 */
2297 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2298 tmp_dom.type = LTTNG_DOMAIN_UST;
2299
2300 switch (domain->type) {
2301 case LTTNG_DOMAIN_LOG4J:
2302 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2303 break;
2304 case LTTNG_DOMAIN_JUL:
2305 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2306 break;
2307 case LTTNG_DOMAIN_PYTHON:
2308 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2309 break;
2310 default:
2311 /* The switch/case we are in makes this impossible */
2312 assert(0);
2313 }
2314
2315 {
2316 char *filter_expression_copy = NULL;
2317 struct lttng_filter_bytecode *filter_copy = NULL;
2318
2319 if (filter) {
2320 const size_t filter_size = sizeof(
2321 struct lttng_filter_bytecode)
2322 + filter->len;
2323
2324 filter_copy = zmalloc(filter_size);
2325 if (!filter_copy) {
2326 ret = LTTNG_ERR_NOMEM;
2327 goto error;
2328 }
2329 memcpy(filter_copy, filter, filter_size);
2330
2331 filter_expression_copy =
2332 strdup(filter_expression);
2333 if (!filter_expression) {
2334 ret = LTTNG_ERR_NOMEM;
2335 }
2336
2337 if (!filter_expression_copy || !filter_copy) {
2338 free(filter_expression_copy);
2339 free(filter_copy);
2340 goto error;
2341 }
2342 }
2343
2344 ret = cmd_enable_event_internal(session, &tmp_dom,
2345 (char *) default_chan_name,
2346 &uevent, filter_expression_copy,
2347 filter_copy, NULL, wpipe);
2348 }
2349
2350 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2351 goto already_enabled;
2352 } else if (ret != LTTNG_OK) {
2353 goto error;
2354 }
2355
2356 /* The wild card * means that everything should be enabled. */
2357 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2358 ret = event_agent_enable_all(usess, agt, event, filter,
2359 filter_expression);
2360 } else {
2361 ret = event_agent_enable(usess, agt, event, filter,
2362 filter_expression);
2363 }
2364 filter = NULL;
2365 filter_expression = NULL;
2366 if (ret != LTTNG_OK) {
2367 goto error;
2368 }
2369
2370 break;
2371 }
2372 default:
2373 ret = LTTNG_ERR_UND;
2374 goto error;
2375 }
2376
2377 ret = LTTNG_OK;
2378
2379 already_enabled:
2380 error:
2381 free(filter_expression);
2382 free(filter);
2383 free(exclusion);
2384 channel_attr_destroy(attr);
2385 rcu_read_unlock();
2386 return ret;
2387 }
2388
2389 /*
2390 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2391 * We own filter, exclusion, and filter_expression.
2392 */
2393 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2394 char *channel_name, struct lttng_event *event,
2395 char *filter_expression,
2396 struct lttng_filter_bytecode *filter,
2397 struct lttng_event_exclusion *exclusion,
2398 int wpipe)
2399 {
2400 return _cmd_enable_event(session, domain, channel_name, event,
2401 filter_expression, filter, exclusion, wpipe, false);
2402 }
2403
2404 /*
2405 * Enable an event which is internal to LTTng. An internal should
2406 * never be made visible to clients and are immune to checks such as
2407 * reserved names.
2408 */
2409 static int cmd_enable_event_internal(struct ltt_session *session,
2410 struct lttng_domain *domain,
2411 char *channel_name, struct lttng_event *event,
2412 char *filter_expression,
2413 struct lttng_filter_bytecode *filter,
2414 struct lttng_event_exclusion *exclusion,
2415 int wpipe)
2416 {
2417 return _cmd_enable_event(session, domain, channel_name, event,
2418 filter_expression, filter, exclusion, wpipe, true);
2419 }
2420
2421 /*
2422 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2423 */
2424 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2425 struct lttng_event **events)
2426 {
2427 int ret;
2428 ssize_t nb_events = 0;
2429
2430 switch (domain) {
2431 case LTTNG_DOMAIN_KERNEL:
2432 nb_events = kernel_list_events(kernel_tracer_fd, events);
2433 if (nb_events < 0) {
2434 ret = LTTNG_ERR_KERN_LIST_FAIL;
2435 goto error;
2436 }
2437 break;
2438 case LTTNG_DOMAIN_UST:
2439 nb_events = ust_app_list_events(events);
2440 if (nb_events < 0) {
2441 ret = LTTNG_ERR_UST_LIST_FAIL;
2442 goto error;
2443 }
2444 break;
2445 case LTTNG_DOMAIN_LOG4J:
2446 case LTTNG_DOMAIN_JUL:
2447 case LTTNG_DOMAIN_PYTHON:
2448 nb_events = agent_list_events(events, domain);
2449 if (nb_events < 0) {
2450 ret = LTTNG_ERR_UST_LIST_FAIL;
2451 goto error;
2452 }
2453 break;
2454 default:
2455 ret = LTTNG_ERR_UND;
2456 goto error;
2457 }
2458
2459 return nb_events;
2460
2461 error:
2462 /* Return negative value to differentiate return code */
2463 return -ret;
2464 }
2465
2466 /*
2467 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2468 */
2469 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2470 struct lttng_event_field **fields)
2471 {
2472 int ret;
2473 ssize_t nb_fields = 0;
2474
2475 switch (domain) {
2476 case LTTNG_DOMAIN_UST:
2477 nb_fields = ust_app_list_event_fields(fields);
2478 if (nb_fields < 0) {
2479 ret = LTTNG_ERR_UST_LIST_FAIL;
2480 goto error;
2481 }
2482 break;
2483 case LTTNG_DOMAIN_KERNEL:
2484 default: /* fall-through */
2485 ret = LTTNG_ERR_UND;
2486 goto error;
2487 }
2488
2489 return nb_fields;
2490
2491 error:
2492 /* Return negative value to differentiate return code */
2493 return -ret;
2494 }
2495
2496 ssize_t cmd_list_syscalls(struct lttng_event **events)
2497 {
2498 return syscall_table_list(events);
2499 }
2500
2501 /*
2502 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2503 *
2504 * Called with session lock held.
2505 */
2506 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2507 enum lttng_domain_type domain, int32_t **pids)
2508 {
2509 int ret;
2510 ssize_t nr_pids = 0;
2511
2512 switch (domain) {
2513 case LTTNG_DOMAIN_KERNEL:
2514 {
2515 struct ltt_kernel_session *ksess;
2516
2517 ksess = session->kernel_session;
2518 nr_pids = kernel_list_tracker_pids(ksess, pids);
2519 if (nr_pids < 0) {
2520 ret = LTTNG_ERR_KERN_LIST_FAIL;
2521 goto error;
2522 }
2523 break;
2524 }
2525 case LTTNG_DOMAIN_UST:
2526 {
2527 struct ltt_ust_session *usess;
2528
2529 usess = session->ust_session;
2530 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2531 if (nr_pids < 0) {
2532 ret = LTTNG_ERR_UST_LIST_FAIL;
2533 goto error;
2534 }
2535 break;
2536 }
2537 case LTTNG_DOMAIN_LOG4J:
2538 case LTTNG_DOMAIN_JUL:
2539 case LTTNG_DOMAIN_PYTHON:
2540 default:
2541 ret = LTTNG_ERR_UND;
2542 goto error;
2543 }
2544
2545 return nr_pids;
2546
2547 error:
2548 /* Return negative value to differentiate return code */
2549 return -ret;
2550 }
2551
2552 /*
2553 * Command LTTNG_START_TRACE processed by the client thread.
2554 *
2555 * Called with session mutex held.
2556 */
2557 int cmd_start_trace(struct ltt_session *session)
2558 {
2559 enum lttng_error_code ret;
2560 unsigned long nb_chan = 0;
2561 struct ltt_kernel_session *ksession;
2562 struct ltt_ust_session *usess;
2563
2564 assert(session);
2565
2566 /* Ease our life a bit ;) */
2567 ksession = session->kernel_session;
2568 usess = session->ust_session;
2569
2570 /* Is the session already started? */
2571 if (session->active) {
2572 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2573 goto error;
2574 }
2575
2576 /*
2577 * Starting a session without channel is useless since after that it's not
2578 * possible to enable channel thus inform the client.
2579 */
2580 if (usess && usess->domain_global.channels) {
2581 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2582 }
2583 if (ksession) {
2584 nb_chan += ksession->channel_count;
2585 }
2586 if (!nb_chan) {
2587 ret = LTTNG_ERR_NO_CHANNEL;
2588 goto error;
2589 }
2590
2591 if (session->output_traces && !session->current_trace_chunk) {
2592 struct lttng_trace_chunk *trace_chunk;
2593
2594 trace_chunk = session_create_new_trace_chunk(
2595 session, NULL, NULL, NULL);
2596 if (!trace_chunk) {
2597 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2598 goto error;
2599 }
2600 assert(!session->current_trace_chunk);
2601 ret = session_set_trace_chunk(session, trace_chunk, NULL);
2602 lttng_trace_chunk_put(trace_chunk);
2603 if (ret) {
2604 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2605 goto error;
2606 }
2607 }
2608
2609 /* Kernel tracing */
2610 if (ksession != NULL) {
2611 DBG("Start kernel tracing session %s", session->name);
2612 ret = start_kernel_session(ksession, kernel_tracer_fd);
2613 if (ret != LTTNG_OK) {
2614 goto error;
2615 }
2616 }
2617
2618 /* Flag session that trace should start automatically */
2619 if (usess) {
2620 int int_ret = ust_app_start_trace_all(usess);
2621
2622 if (int_ret < 0) {
2623 ret = LTTNG_ERR_UST_START_FAIL;
2624 goto error;
2625 }
2626 }
2627
2628 /* Flag this after a successful start. */
2629 session->has_been_started = 1;
2630 session->active = 1;
2631
2632 /*
2633 * Clear the flag that indicates that a rotation was done while the
2634 * session was stopped.
2635 */
2636 session->rotated_after_last_stop = false;
2637
2638 if (session->rotate_timer_period) {
2639 int int_ret = timer_session_rotation_schedule_timer_start(
2640 session, session->rotate_timer_period);
2641
2642 if (int_ret < 0) {
2643 ERR("Failed to enable rotate timer");
2644 ret = LTTNG_ERR_UNK;
2645 goto error;
2646 }
2647 }
2648
2649 ret = LTTNG_OK;
2650
2651 error:
2652 return ret;
2653 }
2654
2655 /*
2656 * Command LTTNG_STOP_TRACE processed by the client thread.
2657 */
2658 int cmd_stop_trace(struct ltt_session *session)
2659 {
2660 int ret;
2661 struct ltt_kernel_channel *kchan;
2662 struct ltt_kernel_session *ksession;
2663 struct ltt_ust_session *usess;
2664 bool error_occurred = false;
2665
2666 assert(session);
2667
2668 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2669 /* Short cut */
2670 ksession = session->kernel_session;
2671 usess = session->ust_session;
2672
2673 /* Session is not active. Skip everythong and inform the client. */
2674 if (!session->active) {
2675 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2676 goto error;
2677 }
2678
2679 /* Kernel tracer */
2680 if (ksession && ksession->active) {
2681 DBG("Stop kernel tracing");
2682
2683 ret = kernel_stop_session(ksession);
2684 if (ret < 0) {
2685 ret = LTTNG_ERR_KERN_STOP_FAIL;
2686 goto error;
2687 }
2688
2689 kernel_wait_quiescent(kernel_tracer_fd);
2690
2691 /* Flush metadata after stopping (if exists) */
2692 if (ksession->metadata_stream_fd >= 0) {
2693 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2694 if (ret < 0) {
2695 ERR("Kernel metadata flush failed");
2696 }
2697 }
2698
2699 /* Flush all buffers after stopping */
2700 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2701 ret = kernel_flush_buffer(kchan);
2702 if (ret < 0) {
2703 ERR("Kernel flush buffer error");
2704 }
2705 }
2706
2707 ksession->active = 0;
2708 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2709 session->id);
2710 }
2711
2712 if (usess && usess->active) {
2713 ret = ust_app_stop_trace_all(usess);
2714 if (ret < 0) {
2715 ret = LTTNG_ERR_UST_STOP_FAIL;
2716 goto error;
2717 }
2718 }
2719
2720 /* Flag inactive after a successful stop. */
2721 session->active = 0;
2722 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2723
2724 error:
2725 return ret;
2726 }
2727
2728 /*
2729 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2730 */
2731 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2732 struct lttng_uri *uris)
2733 {
2734 int ret, i;
2735 struct ltt_kernel_session *ksess = session->kernel_session;
2736 struct ltt_ust_session *usess = session->ust_session;
2737
2738 assert(session);
2739 assert(uris);
2740 assert(nb_uri > 0);
2741
2742 /* Can't set consumer URI if the session is active. */
2743 if (session->active) {
2744 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2745 goto error;
2746 }
2747
2748 /* Set the "global" consumer URIs */
2749 for (i = 0; i < nb_uri; i++) {
2750 ret = add_uri_to_consumer(session,
2751 session->consumer,
2752 &uris[i], LTTNG_DOMAIN_NONE);
2753 if (ret != LTTNG_OK) {
2754 goto error;
2755 }
2756 }
2757
2758 /* Set UST session URIs */
2759 if (session->ust_session) {
2760 for (i = 0; i < nb_uri; i++) {
2761 ret = add_uri_to_consumer(session,
2762 session->ust_session->consumer,
2763 &uris[i], LTTNG_DOMAIN_UST);
2764 if (ret != LTTNG_OK) {
2765 goto error;
2766 }
2767 }
2768 }
2769
2770 /* Set kernel session URIs */
2771 if (session->kernel_session) {
2772 for (i = 0; i < nb_uri; i++) {
2773 ret = add_uri_to_consumer(session,
2774 session->kernel_session->consumer,
2775 &uris[i], LTTNG_DOMAIN_KERNEL);
2776 if (ret != LTTNG_OK) {
2777 goto error;
2778 }
2779 }
2780 }
2781
2782 /*
2783 * Make sure to set the session in output mode after we set URI since a
2784 * session can be created without URL (thus flagged in no output mode).
2785 */
2786 session->output_traces = 1;
2787 if (ksess) {
2788 ksess->output_traces = 1;
2789 }
2790
2791 if (usess) {
2792 usess->output_traces = 1;
2793 }
2794
2795 /* All good! */
2796 ret = LTTNG_OK;
2797
2798 error:
2799 return ret;
2800 }
2801
2802 static
2803 enum lttng_error_code set_session_output_from_descriptor(
2804 struct ltt_session *session,
2805 const struct lttng_session_descriptor *descriptor)
2806 {
2807 int ret;
2808 enum lttng_error_code ret_code = LTTNG_OK;
2809 enum lttng_session_descriptor_type session_type =
2810 lttng_session_descriptor_get_type(descriptor);
2811 enum lttng_session_descriptor_output_type output_type =
2812 lttng_session_descriptor_get_output_type(descriptor);
2813 struct lttng_uri uris[2] = {};
2814 size_t uri_count = 0;
2815
2816 switch (output_type) {
2817 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2818 goto end;
2819 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2820 lttng_session_descriptor_get_local_output_uri(descriptor,
2821 &uris[0]);
2822 uri_count = 1;
2823 break;
2824 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2825 lttng_session_descriptor_get_network_output_uris(descriptor,
2826 &uris[0], &uris[1]);
2827 uri_count = 2;
2828 break;
2829 default:
2830 ret_code = LTTNG_ERR_INVALID;
2831 goto end;
2832 }
2833
2834 switch (session_type) {
2835 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2836 {
2837 struct snapshot_output *new_output = NULL;
2838
2839 new_output = snapshot_output_alloc();
2840 if (!new_output) {
2841 ret_code = LTTNG_ERR_NOMEM;
2842 goto end;
2843 }
2844
2845 ret = snapshot_output_init_with_uri(session,
2846 DEFAULT_SNAPSHOT_MAX_SIZE,
2847 NULL, uris, uri_count, session->consumer,
2848 new_output, &session->snapshot);
2849 if (ret < 0) {
2850 ret_code = (ret == -ENOMEM) ?
2851 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2852 snapshot_output_destroy(new_output);
2853 goto end;
2854 }
2855 snapshot_add_output(&session->snapshot, new_output);
2856 break;
2857 }
2858 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2859 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2860 {
2861 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2862 break;
2863 }
2864 default:
2865 ret_code = LTTNG_ERR_INVALID;
2866 goto end;
2867 }
2868 end:
2869 return ret_code;
2870 }
2871
2872 static
2873 enum lttng_error_code cmd_create_session_from_descriptor(
2874 struct lttng_session_descriptor *descriptor,
2875 const lttng_sock_cred *creds,
2876 const char *home_path)
2877 {
2878 int ret;
2879 enum lttng_error_code ret_code;
2880 const char *session_name;
2881 struct ltt_session *new_session = NULL;
2882 enum lttng_session_descriptor_status descriptor_status;
2883 const char *base_path;
2884
2885 session_lock_list();
2886 if (home_path) {
2887 if (*home_path != '/') {
2888 ERR("Home path provided by client is not absolute");
2889 ret_code = LTTNG_ERR_INVALID;
2890 goto end;
2891 }
2892 }
2893
2894 descriptor_status = lttng_session_descriptor_get_session_name(
2895 descriptor, &session_name);
2896 switch (descriptor_status) {
2897 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
2898 break;
2899 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
2900 session_name = NULL;
2901 break;
2902 default:
2903 ret_code = LTTNG_ERR_INVALID;
2904 goto end;
2905 }
2906 ret = lttng_session_descriptor_get_base_path(descriptor, &base_path);
2907 if (ret) {
2908 ret_code = LTTNG_ERR_INVALID;
2909 goto end;
2910 }
2911 ret_code = session_create(session_name, creds->uid, creds->gid,
2912 base_path, &new_session);
2913 if (ret_code != LTTNG_OK) {
2914 goto end;
2915 }
2916
2917 if (!session_name) {
2918 ret = lttng_session_descriptor_set_session_name(descriptor,
2919 new_session->name);
2920 if (ret) {
2921 ret_code = LTTNG_ERR_SESSION_FAIL;
2922 goto end;
2923 }
2924 }
2925
2926 if (!lttng_session_descriptor_is_output_destination_initialized(
2927 descriptor)) {
2928 /*
2929 * Only include the session's creation time in the output
2930 * destination if the name of the session itself was
2931 * not auto-generated.
2932 */
2933 ret_code = lttng_session_descriptor_set_default_output(
2934 descriptor,
2935 session_name ? &new_session->creation_time : NULL,
2936 home_path);
2937 if (ret_code != LTTNG_OK) {
2938 goto end;
2939 }
2940 } else {
2941 new_session->has_user_specified_directory =
2942 lttng_session_descriptor_has_output_directory(
2943 descriptor);
2944 }
2945
2946 switch (lttng_session_descriptor_get_type(descriptor)) {
2947 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2948 new_session->snapshot_mode = 1;
2949 break;
2950 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2951 new_session->live_timer =
2952 lttng_session_descriptor_live_get_timer_interval(
2953 descriptor);
2954 break;
2955 default:
2956 break;
2957 }
2958
2959 ret_code = set_session_output_from_descriptor(new_session, descriptor);
2960 if (ret_code != LTTNG_OK) {
2961 goto end;
2962 }
2963 new_session->consumer->enabled = 1;
2964 ret_code = LTTNG_OK;
2965 end:
2966 /* Release reference provided by the session_create function. */
2967 session_put(new_session);
2968 if (ret_code != LTTNG_OK && new_session) {
2969 /* Release the global reference on error. */
2970 session_destroy(new_session);
2971 }
2972 session_unlock_list();
2973 return ret_code;
2974 }
2975
2976 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
2977 struct lttng_session_descriptor **return_descriptor)
2978 {
2979 int ret;
2980 size_t payload_size;
2981 struct lttng_dynamic_buffer payload;
2982 struct lttng_buffer_view home_dir_view;
2983 struct lttng_buffer_view session_descriptor_view;
2984 struct lttng_session_descriptor *session_descriptor = NULL;
2985 enum lttng_error_code ret_code;
2986
2987 lttng_dynamic_buffer_init(&payload);
2988 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
2989 LTTNG_PATH_MAX) {
2990 ret_code = LTTNG_ERR_INVALID;
2991 goto error;
2992 }
2993 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
2994 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
2995 ret_code = LTTNG_ERR_INVALID;
2996 goto error;
2997 }
2998
2999 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3000 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3001 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3002 if (ret) {
3003 ret_code = LTTNG_ERR_NOMEM;
3004 goto error;
3005 }
3006
3007 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3008 if (ret <= 0) {
3009 ERR("Reception of session descriptor failed, aborting.");
3010 ret_code = LTTNG_ERR_SESSION_FAIL;
3011 goto error;
3012 }
3013
3014 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3015 &payload,
3016 0,
3017 cmd_ctx->lsm->u.create_session.home_dir_size);
3018 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3019 &payload,
3020 cmd_ctx->lsm->u.create_session.home_dir_size,
3021 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3022
3023 ret = lttng_session_descriptor_create_from_buffer(
3024 &session_descriptor_view, &session_descriptor);
3025 if (ret < 0) {
3026 ERR("Failed to create session descriptor from payload of \"create session\" command");
3027 ret_code = LTTNG_ERR_INVALID;
3028 goto error;
3029 }
3030
3031 /*
3032 * Sets the descriptor's auto-generated properties (name, output) if
3033 * needed.
3034 */
3035 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3036 &cmd_ctx->creds,
3037 home_dir_view.size ? home_dir_view.data : NULL);
3038 if (ret_code != LTTNG_OK) {
3039 goto error;
3040 }
3041
3042 ret_code = LTTNG_OK;
3043 *return_descriptor = session_descriptor;
3044 session_descriptor = NULL;
3045 error:
3046 lttng_dynamic_buffer_reset(&payload);
3047 lttng_session_descriptor_destroy(session_descriptor);
3048 return ret_code;
3049 }
3050
3051 static
3052 void cmd_destroy_session_reply(const struct ltt_session *session,
3053 void *_reply_context)
3054 {
3055 int ret;
3056 ssize_t comm_ret;
3057 const struct cmd_destroy_session_reply_context *reply_context =
3058 _reply_context;
3059 struct lttng_dynamic_buffer payload;
3060 struct lttcomm_session_destroy_command_header cmd_header;
3061 struct lttng_trace_archive_location *location = NULL;
3062 struct lttcomm_lttng_msg llm = {
3063 .cmd_type = LTTNG_DESTROY_SESSION,
3064 .ret_code = LTTNG_OK,
3065 .pid = UINT32_MAX,
3066 .cmd_header_size =
3067 sizeof(struct lttcomm_session_destroy_command_header),
3068 .data_size = 0,
3069 };
3070 size_t payload_size_before_location;
3071
3072 lttng_dynamic_buffer_init(&payload);
3073
3074 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3075 if (ret) {
3076 ERR("Failed to append session destruction message");
3077 goto error;
3078 }
3079
3080 cmd_header.rotation_state =
3081 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3082 session->rotation_state :
3083 LTTNG_ROTATION_STATE_NO_ROTATION);
3084 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3085 sizeof(cmd_header));
3086 if (ret) {
3087 ERR("Failed to append session destruction command header");
3088 goto error;
3089 }
3090
3091 if (!reply_context->implicit_rotation_on_destroy) {
3092 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3093 session->name);
3094 goto send_reply;
3095 }
3096 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3097 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3098 session->name);
3099 goto send_reply;
3100 }
3101
3102 location = session_get_trace_archive_location(session);
3103 if (!location) {
3104 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3105 session->name);
3106 goto error;
3107 }
3108
3109 payload_size_before_location = payload.size;
3110 comm_ret = lttng_trace_archive_location_serialize(location,
3111 &payload);
3112 if (comm_ret < 0) {
3113 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3114 session->name);
3115 goto error;
3116 }
3117 /* Update the message to indicate the location's length. */
3118 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3119 payload.size - payload_size_before_location;
3120 send_reply:
3121 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3122 payload.data, payload.size);
3123 if (comm_ret != (ssize_t) payload.size) {
3124 ERR("Failed to send result of the destruction of session \"%s\" to client",
3125 session->name);
3126 }
3127 error:
3128 ret = close(reply_context->reply_sock_fd);
3129 if (ret) {
3130 PERROR("Failed to close client socket in deferred session destroy reply");
3131 }
3132 lttng_dynamic_buffer_reset(&payload);
3133 free(_reply_context);
3134 }
3135
3136 /*
3137 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3138 *
3139 * Called with session lock held.
3140 */
3141 int cmd_destroy_session(struct ltt_session *session,
3142 struct notification_thread_handle *notification_thread_handle,
3143 int *sock_fd)
3144 {
3145 int ret;
3146 struct cmd_destroy_session_reply_context *reply_context = NULL;
3147
3148 if (sock_fd) {
3149 reply_context = zmalloc(sizeof(*reply_context));
3150 if (!reply_context) {
3151 ret = LTTNG_ERR_NOMEM;
3152 goto end;
3153 }
3154 reply_context->reply_sock_fd = *sock_fd;
3155 }
3156
3157 /* Safety net */
3158 assert(session);
3159
3160 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3161 session->id);
3162 if (session->active) {
3163 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3164 session->name);
3165 ret = cmd_stop_trace(session);
3166 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3167 /* Carry on with the destruction of the session. */
3168 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3169 session->name, lttng_strerror(-ret));
3170 }
3171 }
3172
3173 if (session->rotation_schedule_timer_enabled) {
3174 if (timer_session_rotation_schedule_timer_stop(
3175 session)) {
3176 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3177 session->name);
3178 }
3179 }
3180
3181 if (session->rotate_size) {
3182 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3183 session->rotate_size = 0;
3184 }
3185
3186 if (session->most_recent_chunk_id.is_set &&
3187 session->most_recent_chunk_id.value != 0 &&
3188 session->current_trace_chunk && session->output_traces) {
3189 /*
3190 * Perform a last rotation on destruction if rotations have
3191 * occurred during the session's lifetime.
3192 */
3193 ret = cmd_rotate_session(session, NULL, false);
3194 if (ret != LTTNG_OK) {
3195 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3196 session->name, lttng_strerror(-ret));
3197 }
3198 if (reply_context) {
3199 reply_context->implicit_rotation_on_destroy = true;
3200 }
3201 } else if (session->has_been_started && session->current_trace_chunk) {
3202 /*
3203 * The user has not triggered a session rotation. However, to
3204 * ensure all data has been consumed, the session is rotated
3205 * to a 'null' trace chunk before it is destroyed.
3206 *
3207 * This is a "quiet" rotation meaning that no notification is
3208 * emitted and no renaming of the current trace chunk takes
3209 * place.
3210 */
3211 ret = cmd_rotate_session(session, NULL, true);
3212 if (ret != LTTNG_OK) {
3213 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3214 session->name, lttng_strerror(-ret));
3215 }
3216 }
3217
3218 if (session->shm_path[0]) {
3219 /*
3220 * When a session is created with an explicit shm_path,
3221 * the consumer daemon will create its shared memory files
3222 * at that location and will *not* unlink them. This is normal
3223 * as the intention of that feature is to make it possible
3224 * to retrieve the content of those files should a crash occur.
3225 *
3226 * To ensure the content of those files can be used, the
3227 * sessiond daemon will replicate the content of the metadata
3228 * cache in a metadata file.
3229 *
3230 * On clean-up, it is expected that the consumer daemon will
3231 * unlink the shared memory files and that the session daemon
3232 * will unlink the metadata file. Then, the session's directory
3233 * in the shm path can be removed.
3234 *
3235 * Unfortunately, a flaw in the design of the sessiond's and
3236 * consumerd's tear down of channels makes it impossible to
3237 * determine when the sessiond _and_ the consumerd have both
3238 * destroyed their representation of a channel. For one, the
3239 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3240 * callbacks in both daemons.
3241 *
3242 * However, it is also impossible for the sessiond to know when
3243 * the consumer daemon is done destroying its channel(s) since
3244 * it occurs as a reaction to the closing of the channel's file
3245 * descriptor. There is no resulting communication initiated
3246 * from the consumerd to the sessiond to confirm that the
3247 * operation is compl