0d19042b594f8edfda6817a866cf6931378a8b4b
[lttng-tools.git] / src / bin / lttng-sessiond / session.cpp
1 /*
2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 *
6 */
7
8 #define _LGPL_SOURCE
9 #include <limits.h>
10 #include <inttypes.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <sys/stat.h>
15 #include <urcu.h>
16 #include <dirent.h>
17 #include <sys/types.h>
18 #include <pthread.h>
19
20 #include <common/common.h>
21 #include <common/utils.h>
22 #include <common/trace-chunk.h>
23 #include <common/sessiond-comm/sessiond-comm.h>
24 #include <lttng/location-internal.h>
25 #include "lttng-sessiond.h"
26 #include "kernel.h"
27
28 #include "session.h"
29 #include "utils.h"
30 #include "trace-ust.h"
31 #include "timer.h"
32 #include "cmd.h"
33
34 struct ltt_session_destroy_notifier_element {
35 ltt_session_destroy_notifier notifier;
36 void *user_data;
37 };
38
39 struct ltt_session_clear_notifier_element {
40 ltt_session_clear_notifier notifier;
41 void *user_data;
42 };
43
44 /*
45 * NOTES:
46 *
47 * No ltt_session.lock is taken here because those data structure are widely
48 * spread across the lttng-tools code base so before calling functions below
49 * that can read/write a session, the caller MUST acquire the session lock
50 * using session_lock() and session_unlock().
51 */
52
53 /*
54 * Init tracing session list.
55 *
56 * Please see session.h for more explanation and correct usage of the list.
57 */
58 static struct ltt_session_list ltt_session_list = {
59 .lock = PTHREAD_MUTEX_INITIALIZER,
60 .removal_cond = PTHREAD_COND_INITIALIZER,
61 .next_uuid = 0,
62 .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
63 };
64
65 /* These characters are forbidden in a session name. Used by validate_name. */
66 static const char *forbidden_name_chars = "/";
67
68 /* Global hash table to keep the sessions, indexed by id. */
69 static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
70 /* Global hash table to keep the sessions, indexed by name. */
71 static struct lttng_ht *ltt_sessions_ht_by_name = NULL;
72
73 /*
74 * Validate the session name for forbidden characters.
75 *
76 * Return 0 on success else -1 meaning a forbidden char. has been found.
77 */
78 static int validate_name(const char *name)
79 {
80 int ret;
81 char *tok, *tmp_name;
82
83 LTTNG_ASSERT(name);
84
85 tmp_name = strdup(name);
86 if (!tmp_name) {
87 /* ENOMEM here. */
88 ret = -1;
89 goto error;
90 }
91
92 tok = strpbrk(tmp_name, forbidden_name_chars);
93 if (tok) {
94 DBG("Session name %s contains a forbidden character", name);
95 /* Forbidden character has been found. */
96 ret = -1;
97 goto error;
98 }
99 ret = 0;
100
101 error:
102 free(tmp_name);
103 return ret;
104 }
105
106 /*
107 * Add a ltt_session structure to the global list.
108 *
109 * The caller MUST acquire the session list lock before.
110 * Returns the unique identifier for the session.
111 */
112 static uint64_t add_session_list(struct ltt_session *ls)
113 {
114 LTTNG_ASSERT(ls);
115
116 cds_list_add(&ls->list, &ltt_session_list.head);
117 return ltt_session_list.next_uuid++;
118 }
119
120 /*
121 * Delete a ltt_session structure to the global list.
122 *
123 * The caller MUST acquire the session list lock before.
124 */
125 static void del_session_list(struct ltt_session *ls)
126 {
127 LTTNG_ASSERT(ls);
128
129 cds_list_del(&ls->list);
130 }
131
132 /*
133 * Return a pointer to the session list.
134 */
135 struct ltt_session_list *session_get_list(void)
136 {
137 return &ltt_session_list;
138 }
139
140 /*
141 * Returns once the session list is empty.
142 */
143 void session_list_wait_empty(void)
144 {
145 pthread_mutex_lock(&ltt_session_list.lock);
146 while (!cds_list_empty(&ltt_session_list.head)) {
147 pthread_cond_wait(&ltt_session_list.removal_cond,
148 &ltt_session_list.lock);
149 }
150 pthread_mutex_unlock(&ltt_session_list.lock);
151 }
152
153 /*
154 * Acquire session list lock
155 */
156 void session_lock_list(void)
157 {
158 pthread_mutex_lock(&ltt_session_list.lock);
159 }
160
161 /*
162 * Try to acquire session list lock
163 */
164 int session_trylock_list(void)
165 {
166 return pthread_mutex_trylock(&ltt_session_list.lock);
167 }
168
169 /*
170 * Release session list lock
171 */
172 void session_unlock_list(void)
173 {
174 pthread_mutex_unlock(&ltt_session_list.lock);
175 }
176
177 /*
178 * Get the session's consumer destination type.
179 *
180 * The caller must hold the session lock.
181 */
182 enum consumer_dst_type session_get_consumer_destination_type(
183 const struct ltt_session *session)
184 {
185 /*
186 * The output information is duplicated in both of those session types.
187 * Hence, it doesn't matter from which it is retrieved. However, it is
188 * possible for only one of them to be set.
189 */
190 return session->kernel_session ?
191 session->kernel_session->consumer->type :
192 session->ust_session->consumer->type;
193 }
194
195 /*
196 * Get the session's consumer network hostname.
197 * The caller must ensure that the destination is of type "net".
198 *
199 * The caller must hold the session lock.
200 */
201 const char *session_get_net_consumer_hostname(const struct ltt_session *session)
202 {
203 const char *hostname = NULL;
204 const struct consumer_output *output;
205
206 output = session->kernel_session ?
207 session->kernel_session->consumer :
208 session->ust_session->consumer;
209
210 /*
211 * hostname is assumed to be the same for both control and data
212 * connections.
213 */
214 switch (output->dst.net.control.dtype) {
215 case LTTNG_DST_IPV4:
216 hostname = output->dst.net.control.dst.ipv4;
217 break;
218 case LTTNG_DST_IPV6:
219 hostname = output->dst.net.control.dst.ipv6;
220 break;
221 default:
222 abort();
223 }
224 return hostname;
225 }
226
227 /*
228 * Get the session's consumer network control and data ports.
229 * The caller must ensure that the destination is of type "net".
230 *
231 * The caller must hold the session lock.
232 */
233 void session_get_net_consumer_ports(const struct ltt_session *session,
234 uint16_t *control_port, uint16_t *data_port)
235 {
236 const struct consumer_output *output;
237
238 output = session->kernel_session ?
239 session->kernel_session->consumer :
240 session->ust_session->consumer;
241 *control_port = output->dst.net.control.port;
242 *data_port = output->dst.net.data.port;
243 }
244
245 /*
246 * Get the location of the latest trace archive produced by a rotation.
247 *
248 * The caller must hold the session lock.
249 */
250 struct lttng_trace_archive_location *session_get_trace_archive_location(
251 const struct ltt_session *session)
252 {
253 int ret;
254 struct lttng_trace_archive_location *location = NULL;
255 char *chunk_path = NULL;
256
257 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED ||
258 !session->last_archived_chunk_name) {
259 goto end;
260 }
261
262 switch (session_get_consumer_destination_type(session)) {
263 case CONSUMER_DST_LOCAL:
264 ret = asprintf(&chunk_path,
265 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
266 session_get_base_path(session),
267 session->last_archived_chunk_name);
268 if (ret == -1) {
269 goto end;
270 }
271 location = lttng_trace_archive_location_local_create(
272 chunk_path);
273 break;
274 case CONSUMER_DST_NET:
275 {
276 const char *hostname;
277 uint16_t control_port, data_port;
278
279 hostname = session_get_net_consumer_hostname(session);
280 session_get_net_consumer_ports(session,
281 &control_port,
282 &data_port);
283 location = lttng_trace_archive_location_relay_create(
284 hostname,
285 LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
286 control_port, data_port, session->last_chunk_path);
287 break;
288 }
289 default:
290 abort();
291 }
292 end:
293 free(chunk_path);
294 return location;
295 }
296
297 /*
298 * Allocate the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name HT.
299 *
300 * The session list lock must be held.
301 */
302 static int ltt_sessions_ht_alloc(void)
303 {
304 int ret = 0;
305
306 DBG("Allocating ltt_sessions_ht_by_id");
307 ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
308 if (!ltt_sessions_ht_by_id) {
309 ret = -1;
310 ERR("Failed to allocate ltt_sessions_ht_by_id");
311 goto end;
312 }
313
314 DBG("Allocating ltt_sessions_ht_by_name");
315 ltt_sessions_ht_by_name = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
316 if (!ltt_sessions_ht_by_name) {
317 ret = -1;
318 ERR("Failed to allocate ltt_sessions_ht_by_name");
319 goto end;
320 }
321
322 end:
323 return ret;
324 }
325
326 /*
327 * Destroy the ltt_sessions_ht_by_id HT.
328 *
329 * The session list lock must be held.
330 */
331 static void ltt_sessions_ht_destroy(void)
332 {
333 if (ltt_sessions_ht_by_id) {
334 ht_cleanup_push(ltt_sessions_ht_by_id);
335 ltt_sessions_ht_by_id = NULL;
336 }
337
338 if (ltt_sessions_ht_by_name) {
339 ht_cleanup_push(ltt_sessions_ht_by_name);
340 ltt_sessions_ht_by_name = NULL;
341 }
342
343 return;
344 }
345
346 /*
347 * Add a ltt_session to the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name.
348 * If unallocated, the ltt_sessions_ht_by_id and ltt_sessions_ht_by_name. HTs
349 * are allocated. The session list lock must be held.
350 */
351 static void add_session_ht(struct ltt_session *ls)
352 {
353 int ret;
354
355 LTTNG_ASSERT(ls);
356
357 if (!ltt_sessions_ht_by_id) {
358 ret = ltt_sessions_ht_alloc();
359 if (ret) {
360 ERR("Error allocating the sessions HT");
361 goto end;
362 }
363 }
364
365 /* Should always be present with ltt_sessions_ht_by_id. */
366 LTTNG_ASSERT(ltt_sessions_ht_by_name);
367
368 lttng_ht_node_init_u64(&ls->node, ls->id);
369 lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node);
370
371 lttng_ht_node_init_str(&ls->node_by_name, ls->name);
372 lttng_ht_add_unique_str(ltt_sessions_ht_by_name, &ls->node_by_name);
373
374 end:
375 return;
376 }
377
378 /*
379 * Test if ltt_sessions_ht_by_id/name are empty.
380 * Return 1 if empty, 0 if not empty.
381 * The session list lock must be held.
382 */
383 static int ltt_sessions_ht_empty(void)
384 {
385 unsigned long count;
386
387 if (!ltt_sessions_ht_by_id) {
388 count = 0;
389 goto end;
390 }
391
392 LTTNG_ASSERT(ltt_sessions_ht_by_name);
393
394 count = lttng_ht_get_count(ltt_sessions_ht_by_id);
395 LTTNG_ASSERT(count == lttng_ht_get_count(ltt_sessions_ht_by_name));
396 end:
397 return count ? 0 : 1;
398 }
399
400 /*
401 * Remove a ltt_session from the ltt_sessions_ht_by_id/name.
402 * If empty, the ltt_sessions_ht_by_id/name HTs are freed.
403 * The session list lock must be held.
404 */
405 static void del_session_ht(struct ltt_session *ls)
406 {
407 struct lttng_ht_iter iter;
408 int ret;
409
410 LTTNG_ASSERT(ls);
411 LTTNG_ASSERT(ltt_sessions_ht_by_id);
412 LTTNG_ASSERT(ltt_sessions_ht_by_name);
413
414 iter.iter.node = &ls->node.node;
415 ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter);
416 LTTNG_ASSERT(!ret);
417
418 iter.iter.node = &ls->node_by_name.node;
419 ret = lttng_ht_del(ltt_sessions_ht_by_name, &iter);
420 LTTNG_ASSERT(!ret);
421
422 if (ltt_sessions_ht_empty()) {
423 DBG("Empty ltt_sessions_ht_by_id/name, destroying hast tables");
424 ltt_sessions_ht_destroy();
425 }
426 }
427
428 /*
429 * Acquire session lock
430 */
431 void session_lock(struct ltt_session *session)
432 {
433 LTTNG_ASSERT(session);
434
435 pthread_mutex_lock(&session->lock);
436 }
437
438 /*
439 * Release session lock
440 */
441 void session_unlock(struct ltt_session *session)
442 {
443 LTTNG_ASSERT(session);
444
445 pthread_mutex_unlock(&session->lock);
446 }
447
448 static
449 int _session_set_trace_chunk_no_lock_check(struct ltt_session *session,
450 struct lttng_trace_chunk *new_trace_chunk,
451 struct lttng_trace_chunk **_current_trace_chunk)
452 {
453 int ret = 0;
454 unsigned int i, refs_to_acquire = 0, refs_acquired = 0, refs_to_release = 0;
455 struct cds_lfht_iter iter;
456 struct consumer_socket *socket;
457 struct lttng_trace_chunk *current_trace_chunk;
458 uint64_t chunk_id;
459 enum lttng_trace_chunk_status chunk_status;
460
461 rcu_read_lock();
462 /*
463 * Ownership of current trace chunk is transferred to
464 * `current_trace_chunk`.
465 */
466 current_trace_chunk = session->current_trace_chunk;
467 session->current_trace_chunk = NULL;
468 if (session->ust_session) {
469 lttng_trace_chunk_put(
470 session->ust_session->current_trace_chunk);
471 session->ust_session->current_trace_chunk = NULL;
472 }
473 if (session->kernel_session) {
474 lttng_trace_chunk_put(
475 session->kernel_session->current_trace_chunk);
476 session->kernel_session->current_trace_chunk = NULL;
477 }
478 if (!new_trace_chunk) {
479 ret = 0;
480 goto end;
481 }
482 chunk_status = lttng_trace_chunk_get_id(new_trace_chunk, &chunk_id);
483 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
484
485 refs_to_acquire = 1;
486 refs_to_acquire += !!session->ust_session;
487 refs_to_acquire += !!session->kernel_session;
488
489 for (refs_acquired = 0; refs_acquired < refs_to_acquire;
490 refs_acquired++) {
491 if (!lttng_trace_chunk_get(new_trace_chunk)) {
492 ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
493 session->name);
494 goto error;
495 }
496 }
497
498 if (session->ust_session) {
499 const uint64_t relayd_id =
500 session->ust_session->consumer->net_seq_index;
501 const bool is_local_trace =
502 session->ust_session->consumer->type ==
503 CONSUMER_DST_LOCAL;
504
505 session->ust_session->current_trace_chunk = new_trace_chunk;
506 if (is_local_trace) {
507 enum lttng_error_code ret_error_code;
508
509 ret_error_code = ust_app_create_channel_subdirectories(
510 session->ust_session);
511 if (ret_error_code != LTTNG_OK) {
512 goto error;
513 }
514 }
515 cds_lfht_for_each_entry(
516 session->ust_session->consumer->socks->ht,
517 &iter, socket, node.node) {
518 pthread_mutex_lock(socket->lock);
519 ret = consumer_create_trace_chunk(socket,
520 relayd_id,
521 session->id, new_trace_chunk,
522 DEFAULT_UST_TRACE_DIR);
523 pthread_mutex_unlock(socket->lock);
524 if (ret) {
525 goto error;
526 }
527 }
528 }
529 if (session->kernel_session) {
530 const uint64_t relayd_id =
531 session->kernel_session->consumer->net_seq_index;
532 const bool is_local_trace =
533 session->kernel_session->consumer->type ==
534 CONSUMER_DST_LOCAL;
535
536 session->kernel_session->current_trace_chunk = new_trace_chunk;
537 if (is_local_trace) {
538 enum lttng_error_code ret_error_code;
539
540 ret_error_code = kernel_create_channel_subdirectories(
541 session->kernel_session);
542 if (ret_error_code != LTTNG_OK) {
543 goto error;
544 }
545 }
546 cds_lfht_for_each_entry(
547 session->kernel_session->consumer->socks->ht,
548 &iter, socket, node.node) {
549 pthread_mutex_lock(socket->lock);
550 ret = consumer_create_trace_chunk(socket,
551 relayd_id,
552 session->id, new_trace_chunk,
553 DEFAULT_KERNEL_TRACE_DIR);
554 pthread_mutex_unlock(socket->lock);
555 if (ret) {
556 goto error;
557 }
558 }
559 }
560
561 /*
562 * Update local current trace chunk state last, only if all remote
563 * creations succeeded.
564 */
565 session->current_trace_chunk = new_trace_chunk;
566 LTTNG_OPTIONAL_SET(&session->most_recent_chunk_id, chunk_id);
567 end:
568 if (_current_trace_chunk) {
569 *_current_trace_chunk = current_trace_chunk;
570 current_trace_chunk = NULL;
571 }
572 end_no_move:
573 rcu_read_unlock();
574 lttng_trace_chunk_put(current_trace_chunk);
575 return ret;
576 error:
577 if (session->ust_session) {
578 session->ust_session->current_trace_chunk = NULL;
579 }
580 if (session->kernel_session) {
581 session->kernel_session->current_trace_chunk = NULL;
582 }
583 /*
584 * Release references taken in the case where all references could not
585 * be acquired.
586 */
587 refs_to_release = refs_to_acquire - refs_acquired;
588 for (i = 0; i < refs_to_release; i++) {
589 lttng_trace_chunk_put(new_trace_chunk);
590 }
591 ret = -1;
592 goto end_no_move;
593 }
594
595 struct lttng_trace_chunk *session_create_new_trace_chunk(
596 const struct ltt_session *session,
597 const struct consumer_output *consumer_output_override,
598 const char *session_base_path_override,
599 const char *chunk_name_override)
600 {
601 int ret;
602 struct lttng_trace_chunk *trace_chunk = NULL;
603 enum lttng_trace_chunk_status chunk_status;
604 const time_t chunk_creation_ts = time(NULL);
605 bool is_local_trace;
606 const char *base_path;
607 struct lttng_directory_handle *session_output_directory = NULL;
608 const struct lttng_credentials session_credentials = {
609 .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
610 .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
611 };
612 uint64_t next_chunk_id;
613 const struct consumer_output *output;
614 const char *new_path;
615
616 if (consumer_output_override) {
617 output = consumer_output_override;
618 } else {
619 LTTNG_ASSERT(session->ust_session || session->kernel_session);
620 output = session->ust_session ?
621 session->ust_session->consumer :
622 session->kernel_session->consumer;
623 }
624
625 is_local_trace = output->type == CONSUMER_DST_LOCAL;
626 base_path = session_base_path_override ? :
627 consumer_output_get_base_path(output);
628
629 if (chunk_creation_ts == (time_t) -1) {
630 PERROR("Failed to sample time while creation session \"%s\" trace chunk",
631 session->name);
632 goto error;
633 }
634
635 next_chunk_id = session->most_recent_chunk_id.is_set ?
636 session->most_recent_chunk_id.value + 1 : 0;
637
638 if (session->current_trace_chunk &&
639 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
640 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
641 DEFAULT_CHUNK_TMP_OLD_DIRECTORY);
642 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
643 goto error;
644 }
645 }
646 if (!session->current_trace_chunk) {
647 if (!session->rotated) {
648 new_path = "";
649 } else {
650 new_path = NULL;
651 }
652 } else {
653 new_path = DEFAULT_CHUNK_TMP_NEW_DIRECTORY;
654 }
655
656 trace_chunk = lttng_trace_chunk_create(next_chunk_id,
657 chunk_creation_ts, new_path);
658 if (!trace_chunk) {
659 goto error;
660 }
661
662 if (chunk_name_override) {
663 chunk_status = lttng_trace_chunk_override_name(trace_chunk,
664 chunk_name_override);
665 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
666 goto error;
667 }
668 }
669
670 if (!is_local_trace) {
671 /*
672 * No need to set crendentials and output directory
673 * for remote trace chunks.
674 */
675 goto end;
676 }
677
678 chunk_status = lttng_trace_chunk_set_credentials(trace_chunk,
679 &session_credentials);
680 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
681 goto error;
682 }
683
684 DBG("Creating base output directory of session \"%s\" at %s",
685 session->name, base_path);
686 ret = utils_mkdir_recursive(base_path, S_IRWXU | S_IRWXG,
687 session->uid, session->gid);
688 if (ret) {
689 goto error;
690 }
691 session_output_directory = lttng_directory_handle_create(base_path);
692 if (!session_output_directory) {
693 goto error;
694 }
695 chunk_status = lttng_trace_chunk_set_as_owner(trace_chunk,
696 session_output_directory);
697 lttng_directory_handle_put(session_output_directory);
698 session_output_directory = NULL;
699 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
700 goto error;
701 }
702 end:
703 return trace_chunk;
704 error:
705 lttng_directory_handle_put(session_output_directory);
706 lttng_trace_chunk_put(trace_chunk);
707 trace_chunk = NULL;
708 goto end;
709 }
710
711 int session_close_trace_chunk(struct ltt_session *session,
712 struct lttng_trace_chunk *trace_chunk,
713 enum lttng_trace_chunk_command_type close_command,
714 char *closed_trace_chunk_path)
715 {
716 int ret = 0;
717 bool error_occurred = false;
718 struct cds_lfht_iter iter;
719 struct consumer_socket *socket;
720 enum lttng_trace_chunk_status chunk_status;
721 const time_t chunk_close_timestamp = time(NULL);
722 const char *new_path;
723
724 chunk_status = lttng_trace_chunk_set_close_command(
725 trace_chunk, close_command);
726 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
727 ret = -1;
728 goto end;
729 }
730
731 if (chunk_close_timestamp == (time_t) -1) {
732 ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
733 session->name);
734 ret = -1;
735 goto end;
736 }
737
738 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE && !session->rotated) {
739 /* New chunk stays in session output directory. */
740 new_path = "";
741 } else {
742 /* Use chunk name for new chunk. */
743 new_path = NULL;
744 }
745 if (session->current_trace_chunk &&
746 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
747 /* Rename new chunk path. */
748 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
749 new_path);
750 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
751 ret = -1;
752 goto end;
753 }
754 }
755 if (!lttng_trace_chunk_get_name_overridden(trace_chunk) &&
756 close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION) {
757 const char *old_path;
758
759 if (!session->rotated) {
760 old_path = "";
761 } else {
762 old_path = NULL;
763 }
764 /* We need to move back the .tmp_old_chunk to its rightful place. */
765 chunk_status = lttng_trace_chunk_rename_path(trace_chunk,
766 old_path);
767 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
768 ret = -1;
769 goto end;
770 }
771 }
772 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED) {
773 session->rotated = true;
774 }
775 chunk_status = lttng_trace_chunk_set_close_timestamp(trace_chunk,
776 chunk_close_timestamp);
777 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
778 ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
779 session->name);
780 ret = -1;
781 goto end;
782 }
783
784 if (session->ust_session) {
785 const uint64_t relayd_id =
786 session->ust_session->consumer->net_seq_index;
787
788 cds_lfht_for_each_entry(
789 session->ust_session->consumer->socks->ht,
790 &iter, socket, node.node) {
791 pthread_mutex_lock(socket->lock);
792 ret = consumer_close_trace_chunk(socket,
793 relayd_id,
794 session->id,
795 trace_chunk, closed_trace_chunk_path);
796 pthread_mutex_unlock(socket->lock);
797 if (ret) {
798 ERR("Failed to close trace chunk on user space consumer");
799 error_occurred = true;
800 }
801 }
802 }
803 if (session->kernel_session) {
804 const uint64_t relayd_id =
805 session->kernel_session->consumer->net_seq_index;
806
807 cds_lfht_for_each_entry(
808 session->kernel_session->consumer->socks->ht,
809 &iter, socket, node.node) {
810 pthread_mutex_lock(socket->lock);
811 ret = consumer_close_trace_chunk(socket,
812 relayd_id,
813 session->id,
814 trace_chunk, closed_trace_chunk_path);
815 pthread_mutex_unlock(socket->lock);
816 if (ret) {
817 ERR("Failed to close trace chunk on kernel consumer");
818 error_occurred = true;
819 }
820 }
821 }
822 ret = error_occurred ? -1 : 0;
823 end:
824 return ret;
825 }
826
827 /*
828 * This function skips the metadata channel as the begin/end timestamps of a
829 * metadata packet are useless.
830 *
831 * Moreover, opening a packet after a "clear" will cause problems for live
832 * sessions as it will introduce padding that was not part of the first trace
833 * chunk. The relay daemon expects the content of the metadata stream of
834 * successive metadata trace chunks to be strict supersets of one another.
835 *
836 * For example, flushing a packet at the beginning of the metadata stream of
837 * a trace chunk resulting from a "clear" session command will cause the
838 * size of the metadata stream of the new trace chunk to not match the size of
839 * the metadata stream of the original chunk. This will confuse the relay
840 * daemon as the same "offset" in a metadata stream will no longer point
841 * to the same content.
842 */
843 static
844 enum lttng_error_code session_kernel_open_packets(struct ltt_session *session)
845 {
846 enum lttng_error_code ret = LTTNG_OK;
847 struct consumer_socket *socket;
848 struct lttng_ht_iter iter;
849 struct cds_lfht_node *node;
850 struct ltt_kernel_channel *chan;
851
852 rcu_read_lock();
853
854 cds_lfht_first(session->kernel_session->consumer->socks->ht, &iter.iter);
855 node = cds_lfht_iter_get_node(&iter.iter);
856 socket = container_of(node, typeof(*socket), node.node);
857
858 cds_list_for_each_entry(chan,
859 &session->kernel_session->channel_list.head, list) {
860 int open_ret;
861
862 DBG("Open packet of kernel channel: channel key = %" PRIu64
863 ", session name = %s, session_id = %" PRIu64,
864 chan->key, session->name, session->id);
865
866 open_ret = consumer_open_channel_packets(socket, chan->key);
867 if (open_ret < 0) {
868 /* General error (no known error expected). */
869 ret = LTTNG_ERR_UNK;
870 goto end;
871 }
872 }
873
874 end:
875 rcu_read_unlock();
876 return ret;
877 }
878
879 enum lttng_error_code session_open_packets(struct ltt_session *session)
880 {
881 enum lttng_error_code ret = LTTNG_OK;
882
883 DBG("Opening packets of session channels: session name = %s, session id = %" PRIu64,
884 session->name, session->id);
885
886 if (session->ust_session) {
887 ret = ust_app_open_packets(session);
888 if (ret != LTTNG_OK) {
889 goto end;
890 }
891 }
892
893 if (session->kernel_session) {
894 ret = session_kernel_open_packets(session);
895 if (ret != LTTNG_OK) {
896 goto end;
897 }
898 }
899
900 end:
901 return ret;
902 }
903
904 /*
905 * Set a session's current trace chunk.
906 *
907 * Must be called with the session lock held.
908 */
909 int session_set_trace_chunk(struct ltt_session *session,
910 struct lttng_trace_chunk *new_trace_chunk,
911 struct lttng_trace_chunk **current_trace_chunk)
912 {
913 ASSERT_LOCKED(session->lock);
914 return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk,
915 current_trace_chunk);
916 }
917
918 static
919 void session_notify_destruction(const struct ltt_session *session)
920 {
921 size_t i;
922 const size_t count = lttng_dynamic_array_get_count(
923 &session->destroy_notifiers);
924
925 for (i = 0; i < count; i++) {
926 const struct ltt_session_destroy_notifier_element *element =
927 (ltt_session_destroy_notifier_element *) lttng_dynamic_array_get_element(
928 &session->destroy_notifiers, i);
929
930 element->notifier(session, element->user_data);
931 }
932 }
933
934 /*
935 * Fire each clear notifier once, and remove them from the array.
936 */
937 void session_notify_clear(struct ltt_session *session)
938 {
939 size_t i;
940 const size_t count = lttng_dynamic_array_get_count(
941 &session->clear_notifiers);
942
943 for (i = 0; i < count; i++) {
944 const struct ltt_session_clear_notifier_element *element =
945 (ltt_session_clear_notifier_element *) lttng_dynamic_array_get_element(
946 &session->clear_notifiers, i);
947
948 element->notifier(session, element->user_data);
949 }
950 lttng_dynamic_array_clear(&session->clear_notifiers);
951 }
952
953 static
954 void session_release(struct urcu_ref *ref)
955 {
956 int ret;
957 struct ltt_ust_session *usess;
958 struct ltt_kernel_session *ksess;
959 struct ltt_session *session = container_of(ref, typeof(*session), ref);
960 const bool session_published = session->published;
961
962 LTTNG_ASSERT(!session->chunk_being_archived);
963
964 usess = session->ust_session;
965 ksess = session->kernel_session;
966
967 /* Clean kernel session teardown, keeping data for destroy notifier. */
968 kernel_destroy_session(ksess);
969
970 /* UST session teardown, keeping data for destroy notifier. */
971 if (usess) {
972 /* Close any relayd session */
973 consumer_output_send_destroy_relayd(usess->consumer);
974
975 /* Destroy every UST application related to this session. */
976 ret = ust_app_destroy_trace_all(usess);
977 if (ret) {
978 ERR("Error in ust_app_destroy_trace_all");
979 }
980
981 /* Clean up the rest, keeping destroy notifier data. */
982 trace_ust_destroy_session(usess);
983 }
984
985 /*
986 * Must notify the kernel thread here to update it's poll set in order to
987 * remove the channel(s)' fd just destroyed.
988 */
989 ret = notify_thread_pipe(the_kernel_poll_pipe[1]);
990 if (ret < 0) {
991 PERROR("write kernel poll pipe");
992 }
993
994 DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
995
996 snapshot_destroy(&session->snapshot);
997
998 pthread_mutex_destroy(&session->lock);
999
1000 if (session_published) {
1001 ASSERT_LOCKED(ltt_session_list.lock);
1002 del_session_list(session);
1003 del_session_ht(session);
1004 }
1005 session_notify_destruction(session);
1006
1007 consumer_output_put(session->consumer);
1008 kernel_free_session(ksess);
1009 session->kernel_session = NULL;
1010 if (usess) {
1011 trace_ust_free_session(usess);
1012 session->ust_session = NULL;
1013 }
1014 lttng_dynamic_array_reset(&session->destroy_notifiers);
1015 lttng_dynamic_array_reset(&session->clear_notifiers);
1016 free(session->last_archived_chunk_name);
1017 free(session->base_path);
1018 free(session);
1019 if (session_published) {
1020 /*
1021 * Broadcast after free-ing to ensure the memory is
1022 * reclaimed before the main thread exits.
1023 */
1024 ASSERT_LOCKED(ltt_session_list.lock);
1025 pthread_cond_broadcast(&ltt_session_list.removal_cond);
1026 }
1027 }
1028
1029 /*
1030 * Acquire a reference to a session.
1031 * This function may fail (return false); its return value must be checked.
1032 */
1033 bool session_get(struct ltt_session *session)
1034 {
1035 return urcu_ref_get_unless_zero(&session->ref);
1036 }
1037
1038 /*
1039 * Release a reference to a session.
1040 */
1041 void session_put(struct ltt_session *session)
1042 {
1043 if (!session) {
1044 return;
1045 }
1046 /*
1047 * The session list lock must be held as any session_put()
1048 * may cause the removal of the session from the session_list.
1049 */
1050 ASSERT_LOCKED(ltt_session_list.lock);
1051 LTTNG_ASSERT(session->ref.refcount);
1052 urcu_ref_put(&session->ref, session_release);
1053 }
1054
1055 /*
1056 * Destroy a session.
1057 *
1058 * This method does not immediately release/free the session as other
1059 * components may still hold a reference to the session. However,
1060 * the session should no longer be presented to the user.
1061 *
1062 * Releases the session list's reference to the session
1063 * and marks it as destroyed. Iterations on the session list should be
1064 * mindful of the "destroyed" flag.
1065 */
1066 void session_destroy(struct ltt_session *session)
1067 {
1068 LTTNG_ASSERT(!session->destroyed);
1069 session->destroyed = true;
1070 session_put(session);
1071 }
1072
1073 int session_add_destroy_notifier(struct ltt_session *session,
1074 ltt_session_destroy_notifier notifier, void *user_data)
1075 {
1076 const struct ltt_session_destroy_notifier_element element = {
1077 .notifier = notifier,
1078 .user_data = user_data
1079 };
1080
1081 return lttng_dynamic_array_add_element(&session->destroy_notifiers,
1082 &element);
1083 }
1084
1085 int session_add_clear_notifier(struct ltt_session *session,
1086 ltt_session_clear_notifier notifier, void *user_data)
1087 {
1088 const struct ltt_session_clear_notifier_element element = {
1089 .notifier = notifier,
1090 .user_data = user_data
1091 };
1092
1093 return lttng_dynamic_array_add_element(&session->clear_notifiers,
1094 &element);
1095 }
1096
1097 /*
1098 * Return a ltt_session structure ptr that matches name. If no session found,
1099 * NULL is returned. This must be called with the session list lock held using
1100 * session_lock_list and session_unlock_list.
1101 * A reference to the session is implicitly acquired by this function.
1102 */
1103 struct ltt_session *session_find_by_name(const char *name)
1104 {
1105 struct ltt_session *iter;
1106
1107 LTTNG_ASSERT(name);
1108 ASSERT_LOCKED(ltt_session_list.lock);
1109
1110 DBG2("Trying to find session by name %s", name);
1111
1112 cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
1113 if (!strncmp(iter->name, name, NAME_MAX) &&
1114 !iter->destroyed) {
1115 goto found;
1116 }
1117 }
1118
1119 return NULL;
1120 found:
1121 return session_get(iter) ? iter : NULL;
1122 }
1123
1124 /*
1125 * Return an ltt_session that matches the id. If no session is found,
1126 * NULL is returned. This must be called with rcu_read_lock and
1127 * session list lock held (to guarantee the lifetime of the session).
1128 */
1129 struct ltt_session *session_find_by_id(uint64_t id)
1130 {
1131 struct lttng_ht_node_u64 *node;
1132 struct lttng_ht_iter iter;
1133 struct ltt_session *ls;
1134
1135 ASSERT_LOCKED(ltt_session_list.lock);
1136
1137 if (!ltt_sessions_ht_by_id) {
1138 goto end;
1139 }
1140
1141 lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
1142 node = lttng_ht_iter_get_node_u64(&iter);
1143 if (node == NULL) {
1144 goto end;
1145 }
1146 ls = caa_container_of(node, struct ltt_session, node);
1147
1148 DBG3("Session %" PRIu64 " found by id.", id);
1149 return session_get(ls) ? ls : NULL;
1150
1151 end:
1152 DBG3("Session %" PRIu64 " NOT found by id", id);
1153 return NULL;
1154 }
1155
1156 /*
1157 * Create a new session and add it to the session list.
1158 * Session list lock must be held by the caller.
1159 */
1160 enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
1161 struct ltt_session **out_session)
1162 {
1163 int ret;
1164 enum lttng_error_code ret_code;
1165 struct ltt_session *new_session = NULL;
1166
1167 ASSERT_LOCKED(ltt_session_list.lock);
1168 if (name) {
1169 struct ltt_session *clashing_session;
1170
1171 clashing_session = session_find_by_name(name);
1172 if (clashing_session) {
1173 session_put(clashing_session);
1174 ret_code = LTTNG_ERR_EXIST_SESS;
1175 goto error;
1176 }
1177 }
1178 new_session = (ltt_session *) zmalloc(sizeof(struct ltt_session));
1179 if (!new_session) {
1180 PERROR("Failed to allocate an ltt_session structure");
1181 ret_code = LTTNG_ERR_NOMEM;
1182 goto error;
1183 }
1184
1185 lttng_dynamic_array_init(&new_session->destroy_notifiers,
1186 sizeof(struct ltt_session_destroy_notifier_element),
1187 NULL);
1188 lttng_dynamic_array_init(&new_session->clear_notifiers,
1189 sizeof(struct ltt_session_clear_notifier_element),
1190 NULL);
1191 urcu_ref_init(&new_session->ref);
1192 pthread_mutex_init(&new_session->lock, NULL);
1193
1194 new_session->creation_time = time(NULL);
1195 if (new_session->creation_time == (time_t) -1) {
1196 PERROR("Failed to sample session creation time");
1197 ret_code = LTTNG_ERR_SESSION_FAIL;
1198 goto error;
1199 }
1200
1201 /* Create default consumer output. */
1202 new_session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1203 if (new_session->consumer == NULL) {
1204 ret_code = LTTNG_ERR_NOMEM;
1205 goto error;
1206 }
1207
1208 if (name) {
1209 ret = lttng_strncpy(new_session->name, name, sizeof(new_session->name));
1210 if (ret) {
1211 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1212 goto error;
1213 }
1214 ret = validate_name(name);
1215 if (ret < 0) {
1216 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1217 goto error;
1218 }
1219 } else {
1220 int i = 0;
1221 bool found_name = false;
1222 char datetime[16];
1223 struct tm *timeinfo;
1224
1225 timeinfo = localtime(&new_session->creation_time);
1226 if (!timeinfo) {
1227 ret_code = LTTNG_ERR_SESSION_FAIL;
1228 goto error;
1229 }
1230 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1231 for (i = 0; i < INT_MAX; i++) {
1232 struct ltt_session *clashing_session;
1233
1234 if (i == 0) {
1235 ret = snprintf(new_session->name,
1236 sizeof(new_session->name),
1237 "%s-%s",
1238 DEFAULT_SESSION_NAME,
1239 datetime);
1240 } else {
1241 ret = snprintf(new_session->name,
1242 sizeof(new_session->name),
1243 "%s%d-%s",
1244 DEFAULT_SESSION_NAME, i,
1245 datetime);
1246 }
1247 new_session->name_contains_creation_time = true;
1248 if (ret == -1 || ret >= sizeof(new_session->name)) {
1249 /*
1250 * Null-terminate in case the name is used
1251 * in logging statements.
1252 */
1253 new_session->name[sizeof(new_session->name) - 1] = '\0';
1254 ret_code = LTTNG_ERR_SESSION_FAIL;
1255 goto error;
1256 }
1257
1258 clashing_session =
1259 session_find_by_name(new_session->name);
1260 session_put(clashing_session);
1261 if (!clashing_session) {
1262 found_name = true;
1263 break;
1264 }
1265 }
1266 if (found_name) {
1267 DBG("Generated session name \"%s\"", new_session->name);
1268 new_session->has_auto_generated_name = true;
1269 } else {
1270 ERR("Failed to auto-generate a session name");
1271 ret_code = LTTNG_ERR_SESSION_FAIL;
1272 goto error;
1273 }
1274 }
1275
1276 ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
1277 if (ret < 0) {
1278 if (errno == ENAMETOOLONG) {
1279 new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
1280 ERR("Hostname exceeds the maximal permitted length and has been truncated to %s",
1281 new_session->hostname);
1282 } else {
1283 ret_code = LTTNG_ERR_SESSION_FAIL;
1284 goto error;
1285 }
1286 }
1287
1288 new_session->uid = uid;
1289 new_session->gid = gid;
1290
1291 ret = snapshot_init(&new_session->snapshot);
1292 if (ret < 0) {
1293 ret_code = LTTNG_ERR_NOMEM;
1294 goto error;
1295 }
1296
1297 new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
1298
1299 /* Add new session to the session list. */
1300 new_session->id = add_session_list(new_session);
1301
1302 /*
1303 * Add the new session to the ltt_sessions_ht_by_id.
1304 * No ownership is taken by the hash table; it is merely
1305 * a wrapper around the session list used for faster access
1306 * by session id.
1307 */
1308 add_session_ht(new_session);
1309 new_session->published = true;
1310
1311 /*
1312 * Consumer is left to NULL since the create_session_uri command will
1313 * set it up and, if valid, assign it to the session.
1314 */
1315 DBG("Tracing session %s created with ID %" PRIu64 " by uid = %d, gid = %d",
1316 new_session->name, new_session->id, new_session->uid,
1317 new_session->gid);
1318 ret_code = LTTNG_OK;
1319 end:
1320 if (new_session) {
1321 (void) session_get(new_session);
1322 *out_session = new_session;
1323 }
1324 return ret_code;
1325 error:
1326 session_put(new_session);
1327 new_session = NULL;
1328 goto end;
1329 }
1330
1331 /*
1332 * Check if the UID matches the session. Root user has access to all
1333 * sessions.
1334 */
1335 bool session_access_ok(struct ltt_session *session, uid_t uid)
1336 {
1337 LTTNG_ASSERT(session);
1338 return (uid == session->uid) || uid == 0;
1339 }
1340
1341 /*
1342 * Set a session's rotation state and reset all associated state.
1343 *
1344 * This function resets the rotation state (check timers, pending
1345 * flags, etc.) and sets the result of the last rotation. The result
1346 * can be queries by a liblttng-ctl client.
1347 *
1348 * Be careful of the result passed to this function. For instance,
1349 * on failure to launch a rotation, a client will expect the rotation
1350 * state to be set to "NO_ROTATION". If an error occurred while the
1351 * rotation was "ONGOING", result should be set to "ERROR", which will
1352 * allow a client to report it.
1353 *
1354 * Must be called with the session and session_list locks held.
1355 */
1356 int session_reset_rotation_state(struct ltt_session *session,
1357 enum lttng_rotation_state result)
1358 {
1359 int ret = 0;
1360
1361 ASSERT_LOCKED(ltt_session_list.lock);
1362 ASSERT_LOCKED(session->lock);
1363
1364 session->rotation_state = result;
1365 if (session->rotation_pending_check_timer_enabled) {
1366 ret = timer_session_rotation_pending_check_stop(session);
1367 }
1368 if (session->chunk_being_archived) {
1369 uint64_t chunk_id;
1370 enum lttng_trace_chunk_status chunk_status;
1371
1372 chunk_status = lttng_trace_chunk_get_id(
1373 session->chunk_being_archived,
1374 &chunk_id);
1375 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
1376 LTTNG_OPTIONAL_SET(&session->last_archived_chunk_id,
1377 chunk_id);
1378 lttng_trace_chunk_put(session->chunk_being_archived);
1379 session->chunk_being_archived = NULL;
1380 /*
1381 * Fire the clear reply notifiers if we are completing a clear
1382 * rotation.
1383 */
1384 session_notify_clear(session);
1385 }
1386 return ret;
1387 }
1388
1389 /*
1390 * Sample the id of a session looked up via its name.
1391 * Here the term "sampling" hint the caller that this return the id at a given
1392 * point in time with no guarantee that the session for which the id was
1393 * sampled still exist at that point.
1394 *
1395 * Return 0 when the session is not found,
1396 * Return 1 when the session is found and set `id`.
1397 */
1398 bool sample_session_id_by_name(const char *name, uint64_t *id)
1399 {
1400 bool found = false;
1401 struct lttng_ht_node_str *node;
1402 struct lttng_ht_iter iter;
1403 struct ltt_session *ls;
1404
1405 rcu_read_lock();
1406
1407 if (!ltt_sessions_ht_by_name) {
1408 found = false;
1409 goto end;
1410 }
1411
1412 lttng_ht_lookup(ltt_sessions_ht_by_name, name, &iter);
1413 node = lttng_ht_iter_get_node_str(&iter);
1414 if (node == NULL) {
1415 found = false;
1416 goto end;
1417 }
1418
1419 ls = caa_container_of(node, struct ltt_session, node_by_name);
1420 *id = ls->id;
1421 found = true;
1422
1423 DBG3("Session id `%" PRIu64 "` sampled for session `%s", *id, name);
1424 end:
1425 rcu_read_unlock();
1426 return found;
1427 }
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