Fix: sessiond: assert on lttng_ht_add_unique_str on ltt_sessions_ht_by_name
[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.
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 if (ltt_sessions_ht_empty()) {
419 DBG("Empty ltt_sessions_ht_by_id/name, destroying hast tables");
420 ltt_sessions_ht_destroy();
421 }
422 }
423
424 /*
425 * Acquire session lock
426 */
427 void session_lock(struct ltt_session *session)
428 {
429 LTTNG_ASSERT(session);
430
431 pthread_mutex_lock(&session->lock);
432 }
433
434 /*
435 * Release session lock
436 */
437 void session_unlock(struct ltt_session *session)
438 {
439 LTTNG_ASSERT(session);
440
441 pthread_mutex_unlock(&session->lock);
442 }
443
444 static
445 int _session_set_trace_chunk_no_lock_check(struct ltt_session *session,
446 struct lttng_trace_chunk *new_trace_chunk,
447 struct lttng_trace_chunk **_current_trace_chunk)
448 {
449 int ret = 0;
450 unsigned int i, refs_to_acquire = 0, refs_acquired = 0, refs_to_release = 0;
451 struct cds_lfht_iter iter;
452 struct consumer_socket *socket;
453 struct lttng_trace_chunk *current_trace_chunk;
454 uint64_t chunk_id;
455 enum lttng_trace_chunk_status chunk_status;
456
457 rcu_read_lock();
458 /*
459 * Ownership of current trace chunk is transferred to
460 * `current_trace_chunk`.
461 */
462 current_trace_chunk = session->current_trace_chunk;
463 session->current_trace_chunk = NULL;
464 if (session->ust_session) {
465 lttng_trace_chunk_put(
466 session->ust_session->current_trace_chunk);
467 session->ust_session->current_trace_chunk = NULL;
468 }
469 if (session->kernel_session) {
470 lttng_trace_chunk_put(
471 session->kernel_session->current_trace_chunk);
472 session->kernel_session->current_trace_chunk = NULL;
473 }
474 if (!new_trace_chunk) {
475 ret = 0;
476 goto end;
477 }
478 chunk_status = lttng_trace_chunk_get_id(new_trace_chunk, &chunk_id);
479 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
480
481 refs_to_acquire = 1;
482 refs_to_acquire += !!session->ust_session;
483 refs_to_acquire += !!session->kernel_session;
484
485 for (refs_acquired = 0; refs_acquired < refs_to_acquire;
486 refs_acquired++) {
487 if (!lttng_trace_chunk_get(new_trace_chunk)) {
488 ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
489 session->name);
490 goto error;
491 }
492 }
493
494 if (session->ust_session) {
495 const uint64_t relayd_id =
496 session->ust_session->consumer->net_seq_index;
497 const bool is_local_trace =
498 session->ust_session->consumer->type ==
499 CONSUMER_DST_LOCAL;
500
501 session->ust_session->current_trace_chunk = new_trace_chunk;
502 if (is_local_trace) {
503 enum lttng_error_code ret_error_code;
504
505 ret_error_code = ust_app_create_channel_subdirectories(
506 session->ust_session);
507 if (ret_error_code != LTTNG_OK) {
508 goto error;
509 }
510 }
511 cds_lfht_for_each_entry(
512 session->ust_session->consumer->socks->ht,
513 &iter, socket, node.node) {
514 pthread_mutex_lock(socket->lock);
515 ret = consumer_create_trace_chunk(socket,
516 relayd_id,
517 session->id, new_trace_chunk,
518 DEFAULT_UST_TRACE_DIR);
519 pthread_mutex_unlock(socket->lock);
520 if (ret) {
521 goto error;
522 }
523 }
524 }
525 if (session->kernel_session) {
526 const uint64_t relayd_id =
527 session->kernel_session->consumer->net_seq_index;
528 const bool is_local_trace =
529 session->kernel_session->consumer->type ==
530 CONSUMER_DST_LOCAL;
531
532 session->kernel_session->current_trace_chunk = new_trace_chunk;
533 if (is_local_trace) {
534 enum lttng_error_code ret_error_code;
535
536 ret_error_code = kernel_create_channel_subdirectories(
537 session->kernel_session);
538 if (ret_error_code != LTTNG_OK) {
539 goto error;
540 }
541 }
542 cds_lfht_for_each_entry(
543 session->kernel_session->consumer->socks->ht,
544 &iter, socket, node.node) {
545 pthread_mutex_lock(socket->lock);
546 ret = consumer_create_trace_chunk(socket,
547 relayd_id,
548 session->id, new_trace_chunk,
549 DEFAULT_KERNEL_TRACE_DIR);
550 pthread_mutex_unlock(socket->lock);
551 if (ret) {
552 goto error;
553 }
554 }
555 }
556
557 /*
558 * Update local current trace chunk state last, only if all remote
559 * creations succeeded.
560 */
561 session->current_trace_chunk = new_trace_chunk;
562 LTTNG_OPTIONAL_SET(&session->most_recent_chunk_id, chunk_id);
563 end:
564 if (_current_trace_chunk) {
565 *_current_trace_chunk = current_trace_chunk;
566 current_trace_chunk = NULL;
567 }
568 end_no_move:
569 rcu_read_unlock();
570 lttng_trace_chunk_put(current_trace_chunk);
571 return ret;
572 error:
573 if (session->ust_session) {
574 session->ust_session->current_trace_chunk = NULL;
575 }
576 if (session->kernel_session) {
577 session->kernel_session->current_trace_chunk = NULL;
578 }
579 /*
580 * Release references taken in the case where all references could not
581 * be acquired.
582 */
583 refs_to_release = refs_to_acquire - refs_acquired;
584 for (i = 0; i < refs_to_release; i++) {
585 lttng_trace_chunk_put(new_trace_chunk);
586 }
587 ret = -1;
588 goto end_no_move;
589 }
590
591 struct lttng_trace_chunk *session_create_new_trace_chunk(
592 const struct ltt_session *session,
593 const struct consumer_output *consumer_output_override,
594 const char *session_base_path_override,
595 const char *chunk_name_override)
596 {
597 int ret;
598 struct lttng_trace_chunk *trace_chunk = NULL;
599 enum lttng_trace_chunk_status chunk_status;
600 const time_t chunk_creation_ts = time(NULL);
601 bool is_local_trace;
602 const char *base_path;
603 struct lttng_directory_handle *session_output_directory = NULL;
604 const struct lttng_credentials session_credentials = {
605 .uid = LTTNG_OPTIONAL_INIT_VALUE(session->uid),
606 .gid = LTTNG_OPTIONAL_INIT_VALUE(session->gid),
607 };
608 uint64_t next_chunk_id;
609 const struct consumer_output *output;
610 const char *new_path;
611
612 if (consumer_output_override) {
613 output = consumer_output_override;
614 } else {
615 LTTNG_ASSERT(session->ust_session || session->kernel_session);
616 output = session->ust_session ?
617 session->ust_session->consumer :
618 session->kernel_session->consumer;
619 }
620
621 is_local_trace = output->type == CONSUMER_DST_LOCAL;
622 base_path = session_base_path_override ? :
623 consumer_output_get_base_path(output);
624
625 if (chunk_creation_ts == (time_t) -1) {
626 PERROR("Failed to sample time while creation session \"%s\" trace chunk",
627 session->name);
628 goto error;
629 }
630
631 next_chunk_id = session->most_recent_chunk_id.is_set ?
632 session->most_recent_chunk_id.value + 1 : 0;
633
634 if (session->current_trace_chunk &&
635 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
636 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
637 DEFAULT_CHUNK_TMP_OLD_DIRECTORY);
638 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
639 goto error;
640 }
641 }
642 if (!session->current_trace_chunk) {
643 if (!session->rotated) {
644 new_path = "";
645 } else {
646 new_path = NULL;
647 }
648 } else {
649 new_path = DEFAULT_CHUNK_TMP_NEW_DIRECTORY;
650 }
651
652 trace_chunk = lttng_trace_chunk_create(next_chunk_id,
653 chunk_creation_ts, new_path);
654 if (!trace_chunk) {
655 goto error;
656 }
657
658 if (chunk_name_override) {
659 chunk_status = lttng_trace_chunk_override_name(trace_chunk,
660 chunk_name_override);
661 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
662 goto error;
663 }
664 }
665
666 if (!is_local_trace) {
667 /*
668 * No need to set crendentials and output directory
669 * for remote trace chunks.
670 */
671 goto end;
672 }
673
674 chunk_status = lttng_trace_chunk_set_credentials(trace_chunk,
675 &session_credentials);
676 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
677 goto error;
678 }
679
680 DBG("Creating base output directory of session \"%s\" at %s",
681 session->name, base_path);
682 ret = utils_mkdir_recursive(base_path, S_IRWXU | S_IRWXG,
683 session->uid, session->gid);
684 if (ret) {
685 goto error;
686 }
687 session_output_directory = lttng_directory_handle_create(base_path);
688 if (!session_output_directory) {
689 goto error;
690 }
691 chunk_status = lttng_trace_chunk_set_as_owner(trace_chunk,
692 session_output_directory);
693 lttng_directory_handle_put(session_output_directory);
694 session_output_directory = NULL;
695 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
696 goto error;
697 }
698 end:
699 return trace_chunk;
700 error:
701 lttng_directory_handle_put(session_output_directory);
702 lttng_trace_chunk_put(trace_chunk);
703 trace_chunk = NULL;
704 goto end;
705 }
706
707 int session_close_trace_chunk(struct ltt_session *session,
708 struct lttng_trace_chunk *trace_chunk,
709 enum lttng_trace_chunk_command_type close_command,
710 char *closed_trace_chunk_path)
711 {
712 int ret = 0;
713 bool error_occurred = false;
714 struct cds_lfht_iter iter;
715 struct consumer_socket *socket;
716 enum lttng_trace_chunk_status chunk_status;
717 const time_t chunk_close_timestamp = time(NULL);
718 const char *new_path;
719
720 chunk_status = lttng_trace_chunk_set_close_command(
721 trace_chunk, close_command);
722 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
723 ret = -1;
724 goto end;
725 }
726
727 if (chunk_close_timestamp == (time_t) -1) {
728 ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
729 session->name);
730 ret = -1;
731 goto end;
732 }
733
734 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE && !session->rotated) {
735 /* New chunk stays in session output directory. */
736 new_path = "";
737 } else {
738 /* Use chunk name for new chunk. */
739 new_path = NULL;
740 }
741 if (session->current_trace_chunk &&
742 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
743 /* Rename new chunk path. */
744 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
745 new_path);
746 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
747 ret = -1;
748 goto end;
749 }
750 }
751 if (!lttng_trace_chunk_get_name_overridden(trace_chunk) &&
752 close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION) {
753 const char *old_path;
754
755 if (!session->rotated) {
756 old_path = "";
757 } else {
758 old_path = NULL;
759 }
760 /* We need to move back the .tmp_old_chunk to its rightful place. */
761 chunk_status = lttng_trace_chunk_rename_path(trace_chunk,
762 old_path);
763 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
764 ret = -1;
765 goto end;
766 }
767 }
768 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED) {
769 session->rotated = true;
770 }
771 chunk_status = lttng_trace_chunk_set_close_timestamp(trace_chunk,
772 chunk_close_timestamp);
773 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
774 ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
775 session->name);
776 ret = -1;
777 goto end;
778 }
779
780 if (session->ust_session) {
781 const uint64_t relayd_id =
782 session->ust_session->consumer->net_seq_index;
783
784 cds_lfht_for_each_entry(
785 session->ust_session->consumer->socks->ht,
786 &iter, socket, node.node) {
787 pthread_mutex_lock(socket->lock);
788 ret = consumer_close_trace_chunk(socket,
789 relayd_id,
790 session->id,
791 trace_chunk, closed_trace_chunk_path);
792 pthread_mutex_unlock(socket->lock);
793 if (ret) {
794 ERR("Failed to close trace chunk on user space consumer");
795 error_occurred = true;
796 }
797 }
798 }
799 if (session->kernel_session) {
800 const uint64_t relayd_id =
801 session->kernel_session->consumer->net_seq_index;
802
803 cds_lfht_for_each_entry(
804 session->kernel_session->consumer->socks->ht,
805 &iter, socket, node.node) {
806 pthread_mutex_lock(socket->lock);
807 ret = consumer_close_trace_chunk(socket,
808 relayd_id,
809 session->id,
810 trace_chunk, closed_trace_chunk_path);
811 pthread_mutex_unlock(socket->lock);
812 if (ret) {
813 ERR("Failed to close trace chunk on kernel consumer");
814 error_occurred = true;
815 }
816 }
817 }
818 ret = error_occurred ? -1 : 0;
819 end:
820 return ret;
821 }
822
823 /*
824 * This function skips the metadata channel as the begin/end timestamps of a
825 * metadata packet are useless.
826 *
827 * Moreover, opening a packet after a "clear" will cause problems for live
828 * sessions as it will introduce padding that was not part of the first trace
829 * chunk. The relay daemon expects the content of the metadata stream of
830 * successive metadata trace chunks to be strict supersets of one another.
831 *
832 * For example, flushing a packet at the beginning of the metadata stream of
833 * a trace chunk resulting from a "clear" session command will cause the
834 * size of the metadata stream of the new trace chunk to not match the size of
835 * the metadata stream of the original chunk. This will confuse the relay
836 * daemon as the same "offset" in a metadata stream will no longer point
837 * to the same content.
838 */
839 static
840 enum lttng_error_code session_kernel_open_packets(struct ltt_session *session)
841 {
842 enum lttng_error_code ret = LTTNG_OK;
843 struct consumer_socket *socket;
844 struct lttng_ht_iter iter;
845 struct cds_lfht_node *node;
846 struct ltt_kernel_channel *chan;
847
848 rcu_read_lock();
849
850 cds_lfht_first(session->kernel_session->consumer->socks->ht, &iter.iter);
851 node = cds_lfht_iter_get_node(&iter.iter);
852 socket = container_of(node, typeof(*socket), node.node);
853
854 cds_list_for_each_entry(chan,
855 &session->kernel_session->channel_list.head, list) {
856 int open_ret;
857
858 DBG("Open packet of kernel channel: channel key = %" PRIu64
859 ", session name = %s, session_id = %" PRIu64,
860 chan->key, session->name, session->id);
861
862 open_ret = consumer_open_channel_packets(socket, chan->key);
863 if (open_ret < 0) {
864 /* General error (no known error expected). */
865 ret = LTTNG_ERR_UNK;
866 goto end;
867 }
868 }
869
870 end:
871 rcu_read_unlock();
872 return ret;
873 }
874
875 enum lttng_error_code session_open_packets(struct ltt_session *session)
876 {
877 enum lttng_error_code ret = LTTNG_OK;
878
879 DBG("Opening packets of session channels: session name = %s, session id = %" PRIu64,
880 session->name, session->id);
881
882 if (session->ust_session) {
883 ret = ust_app_open_packets(session);
884 if (ret != LTTNG_OK) {
885 goto end;
886 }
887 }
888
889 if (session->kernel_session) {
890 ret = session_kernel_open_packets(session);
891 if (ret != LTTNG_OK) {
892 goto end;
893 }
894 }
895
896 end:
897 return ret;
898 }
899
900 /*
901 * Set a session's current trace chunk.
902 *
903 * Must be called with the session lock held.
904 */
905 int session_set_trace_chunk(struct ltt_session *session,
906 struct lttng_trace_chunk *new_trace_chunk,
907 struct lttng_trace_chunk **current_trace_chunk)
908 {
909 ASSERT_LOCKED(session->lock);
910 return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk,
911 current_trace_chunk);
912 }
913
914 static
915 void session_notify_destruction(const struct ltt_session *session)
916 {
917 size_t i;
918 const size_t count = lttng_dynamic_array_get_count(
919 &session->destroy_notifiers);
920
921 for (i = 0; i < count; i++) {
922 const struct ltt_session_destroy_notifier_element *element =
923 (ltt_session_destroy_notifier_element *) lttng_dynamic_array_get_element(
924 &session->destroy_notifiers, i);
925
926 element->notifier(session, element->user_data);
927 }
928 }
929
930 /*
931 * Fire each clear notifier once, and remove them from the array.
932 */
933 void session_notify_clear(struct ltt_session *session)
934 {
935 size_t i;
936 const size_t count = lttng_dynamic_array_get_count(
937 &session->clear_notifiers);
938
939 for (i = 0; i < count; i++) {
940 const struct ltt_session_clear_notifier_element *element =
941 (ltt_session_clear_notifier_element *) lttng_dynamic_array_get_element(
942 &session->clear_notifiers, i);
943
944 element->notifier(session, element->user_data);
945 }
946 lttng_dynamic_array_clear(&session->clear_notifiers);
947 }
948
949 static
950 void session_release(struct urcu_ref *ref)
951 {
952 int ret;
953 struct ltt_ust_session *usess;
954 struct ltt_kernel_session *ksess;
955 struct ltt_session *session = container_of(ref, typeof(*session), ref);
956 const bool session_published = session->published;
957
958 LTTNG_ASSERT(!session->chunk_being_archived);
959
960 usess = session->ust_session;
961 ksess = session->kernel_session;
962
963 /* Clean kernel session teardown, keeping data for destroy notifier. */
964 kernel_destroy_session(ksess);
965
966 /* UST session teardown, keeping data for destroy notifier. */
967 if (usess) {
968 /* Close any relayd session */
969 consumer_output_send_destroy_relayd(usess->consumer);
970
971 /* Destroy every UST application related to this session. */
972 ret = ust_app_destroy_trace_all(usess);
973 if (ret) {
974 ERR("Error in ust_app_destroy_trace_all");
975 }
976
977 /* Clean up the rest, keeping destroy notifier data. */
978 trace_ust_destroy_session(usess);
979 }
980
981 /*
982 * Must notify the kernel thread here to update it's poll set in order to
983 * remove the channel(s)' fd just destroyed.
984 */
985 ret = notify_thread_pipe(the_kernel_poll_pipe[1]);
986 if (ret < 0) {
987 PERROR("write kernel poll pipe");
988 }
989
990 DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
991
992 snapshot_destroy(&session->snapshot);
993
994 pthread_mutex_destroy(&session->lock);
995
996 if (session_published) {
997 ASSERT_LOCKED(ltt_session_list.lock);
998 del_session_list(session);
999 del_session_ht(session);
1000 }
1001 session_notify_destruction(session);
1002
1003 consumer_output_put(session->consumer);
1004 kernel_free_session(ksess);
1005 session->kernel_session = NULL;
1006 if (usess) {
1007 trace_ust_free_session(usess);
1008 session->ust_session = NULL;
1009 }
1010 lttng_dynamic_array_reset(&session->destroy_notifiers);
1011 lttng_dynamic_array_reset(&session->clear_notifiers);
1012 free(session->last_archived_chunk_name);
1013 free(session->base_path);
1014 free(session);
1015 if (session_published) {
1016 /*
1017 * Broadcast after free-ing to ensure the memory is
1018 * reclaimed before the main thread exits.
1019 */
1020 ASSERT_LOCKED(ltt_session_list.lock);
1021 pthread_cond_broadcast(&ltt_session_list.removal_cond);
1022 }
1023 }
1024
1025 /*
1026 * Acquire a reference to a session.
1027 * This function may fail (return false); its return value must be checked.
1028 */
1029 bool session_get(struct ltt_session *session)
1030 {
1031 return urcu_ref_get_unless_zero(&session->ref);
1032 }
1033
1034 /*
1035 * Release a reference to a session.
1036 */
1037 void session_put(struct ltt_session *session)
1038 {
1039 if (!session) {
1040 return;
1041 }
1042 /*
1043 * The session list lock must be held as any session_put()
1044 * may cause the removal of the session from the session_list.
1045 */
1046 ASSERT_LOCKED(ltt_session_list.lock);
1047 LTTNG_ASSERT(session->ref.refcount);
1048 urcu_ref_put(&session->ref, session_release);
1049 }
1050
1051 /*
1052 * Destroy a session.
1053 *
1054 * This method does not immediately release/free the session as other
1055 * components may still hold a reference to the session. However,
1056 * the session should no longer be presented to the user.
1057 *
1058 * Releases the session list's reference to the session
1059 * and marks it as destroyed. Iterations on the session list should be
1060 * mindful of the "destroyed" flag.
1061 */
1062 void session_destroy(struct ltt_session *session)
1063 {
1064 int ret;
1065 struct lttng_ht_iter iter;
1066
1067 LTTNG_ASSERT(!session->destroyed);
1068 session->destroyed = true;
1069
1070 /*
1071 * Remove immediately from the "session by name" hash table. Only one
1072 * session is expected to exist with a given name for at any given time.
1073 *
1074 * Even if a session still technically exists for a little while longer,
1075 * there is no point in performing action on a "destroyed" session.
1076 */
1077 iter.iter.node = &session->node_by_name.node;
1078 ret = lttng_ht_del(ltt_sessions_ht_by_name, &iter);
1079 LTTNG_ASSERT(!ret);
1080
1081 session_put(session);
1082 }
1083
1084 int session_add_destroy_notifier(struct ltt_session *session,
1085 ltt_session_destroy_notifier notifier, void *user_data)
1086 {
1087 const struct ltt_session_destroy_notifier_element element = {
1088 .notifier = notifier,
1089 .user_data = user_data
1090 };
1091
1092 return lttng_dynamic_array_add_element(&session->destroy_notifiers,
1093 &element);
1094 }
1095
1096 int session_add_clear_notifier(struct ltt_session *session,
1097 ltt_session_clear_notifier notifier, void *user_data)
1098 {
1099 const struct ltt_session_clear_notifier_element element = {
1100 .notifier = notifier,
1101 .user_data = user_data
1102 };
1103
1104 return lttng_dynamic_array_add_element(&session->clear_notifiers,
1105 &element);
1106 }
1107
1108 /*
1109 * Return a ltt_session structure ptr that matches name. If no session found,
1110 * NULL is returned. This must be called with the session list lock held using
1111 * session_lock_list and session_unlock_list.
1112 * A reference to the session is implicitly acquired by this function.
1113 */
1114 struct ltt_session *session_find_by_name(const char *name)
1115 {
1116 struct ltt_session *iter;
1117
1118 LTTNG_ASSERT(name);
1119 ASSERT_LOCKED(ltt_session_list.lock);
1120
1121 DBG2("Trying to find session by name %s", name);
1122
1123 cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
1124 if (!strncmp(iter->name, name, NAME_MAX) &&
1125 !iter->destroyed) {
1126 goto found;
1127 }
1128 }
1129
1130 return NULL;
1131 found:
1132 return session_get(iter) ? iter : NULL;
1133 }
1134
1135 /*
1136 * Return an ltt_session that matches the id. If no session is found,
1137 * NULL is returned. This must be called with rcu_read_lock and
1138 * session list lock held (to guarantee the lifetime of the session).
1139 */
1140 struct ltt_session *session_find_by_id(uint64_t id)
1141 {
1142 struct lttng_ht_node_u64 *node;
1143 struct lttng_ht_iter iter;
1144 struct ltt_session *ls;
1145
1146 ASSERT_LOCKED(ltt_session_list.lock);
1147
1148 if (!ltt_sessions_ht_by_id) {
1149 goto end;
1150 }
1151
1152 lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
1153 node = lttng_ht_iter_get_node_u64(&iter);
1154 if (node == NULL) {
1155 goto end;
1156 }
1157 ls = caa_container_of(node, struct ltt_session, node);
1158
1159 DBG3("Session %" PRIu64 " found by id.", id);
1160 return session_get(ls) ? ls : NULL;
1161
1162 end:
1163 DBG3("Session %" PRIu64 " NOT found by id", id);
1164 return NULL;
1165 }
1166
1167 /*
1168 * Create a new session and add it to the session list.
1169 * Session list lock must be held by the caller.
1170 */
1171 enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
1172 struct ltt_session **out_session)
1173 {
1174 int ret;
1175 enum lttng_error_code ret_code;
1176 struct ltt_session *new_session = NULL;
1177
1178 ASSERT_LOCKED(ltt_session_list.lock);
1179 if (name) {
1180 struct ltt_session *clashing_session;
1181
1182 clashing_session = session_find_by_name(name);
1183 if (clashing_session) {
1184 session_put(clashing_session);
1185 ret_code = LTTNG_ERR_EXIST_SESS;
1186 goto error;
1187 }
1188 }
1189 new_session = (ltt_session *) zmalloc(sizeof(struct ltt_session));
1190 if (!new_session) {
1191 PERROR("Failed to allocate an ltt_session structure");
1192 ret_code = LTTNG_ERR_NOMEM;
1193 goto error;
1194 }
1195
1196 lttng_dynamic_array_init(&new_session->destroy_notifiers,
1197 sizeof(struct ltt_session_destroy_notifier_element),
1198 NULL);
1199 lttng_dynamic_array_init(&new_session->clear_notifiers,
1200 sizeof(struct ltt_session_clear_notifier_element),
1201 NULL);
1202 urcu_ref_init(&new_session->ref);
1203 pthread_mutex_init(&new_session->lock, NULL);
1204
1205 new_session->creation_time = time(NULL);
1206 if (new_session->creation_time == (time_t) -1) {
1207 PERROR("Failed to sample session creation time");
1208 ret_code = LTTNG_ERR_SESSION_FAIL;
1209 goto error;
1210 }
1211
1212 /* Create default consumer output. */
1213 new_session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1214 if (new_session->consumer == NULL) {
1215 ret_code = LTTNG_ERR_NOMEM;
1216 goto error;
1217 }
1218
1219 if (name) {
1220 ret = lttng_strncpy(new_session->name, name, sizeof(new_session->name));
1221 if (ret) {
1222 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1223 goto error;
1224 }
1225 ret = validate_name(name);
1226 if (ret < 0) {
1227 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1228 goto error;
1229 }
1230 } else {
1231 int i = 0;
1232 bool found_name = false;
1233 char datetime[16];
1234 struct tm *timeinfo;
1235
1236 timeinfo = localtime(&new_session->creation_time);
1237 if (!timeinfo) {
1238 ret_code = LTTNG_ERR_SESSION_FAIL;
1239 goto error;
1240 }
1241 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1242 for (i = 0; i < INT_MAX; i++) {
1243 struct ltt_session *clashing_session;
1244
1245 if (i == 0) {
1246 ret = snprintf(new_session->name,
1247 sizeof(new_session->name),
1248 "%s-%s",
1249 DEFAULT_SESSION_NAME,
1250 datetime);
1251 } else {
1252 ret = snprintf(new_session->name,
1253 sizeof(new_session->name),
1254 "%s%d-%s",
1255 DEFAULT_SESSION_NAME, i,
1256 datetime);
1257 }
1258 new_session->name_contains_creation_time = true;
1259 if (ret == -1 || ret >= sizeof(new_session->name)) {
1260 /*
1261 * Null-terminate in case the name is used
1262 * in logging statements.
1263 */
1264 new_session->name[sizeof(new_session->name) - 1] = '\0';
1265 ret_code = LTTNG_ERR_SESSION_FAIL;
1266 goto error;
1267 }
1268
1269 clashing_session =
1270 session_find_by_name(new_session->name);
1271 session_put(clashing_session);
1272 if (!clashing_session) {
1273 found_name = true;
1274 break;
1275 }
1276 }
1277 if (found_name) {
1278 DBG("Generated session name \"%s\"", new_session->name);
1279 new_session->has_auto_generated_name = true;
1280 } else {
1281 ERR("Failed to auto-generate a session name");
1282 ret_code = LTTNG_ERR_SESSION_FAIL;
1283 goto error;
1284 }
1285 }
1286
1287 ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
1288 if (ret < 0) {
1289 if (errno == ENAMETOOLONG) {
1290 new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
1291 ERR("Hostname exceeds the maximal permitted length and has been truncated to %s",
1292 new_session->hostname);
1293 } else {
1294 ret_code = LTTNG_ERR_SESSION_FAIL;
1295 goto error;
1296 }
1297 }
1298
1299 new_session->uid = uid;
1300 new_session->gid = gid;
1301
1302 ret = snapshot_init(&new_session->snapshot);
1303 if (ret < 0) {
1304 ret_code = LTTNG_ERR_NOMEM;
1305 goto error;
1306 }
1307
1308 new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
1309
1310 /* Add new session to the session list. */
1311 new_session->id = add_session_list(new_session);
1312
1313 /*
1314 * Add the new session to the ltt_sessions_ht_by_id.
1315 * No ownership is taken by the hash table; it is merely
1316 * a wrapper around the session list used for faster access
1317 * by session id.
1318 */
1319 add_session_ht(new_session);
1320 new_session->published = true;
1321
1322 /*
1323 * Consumer is left to NULL since the create_session_uri command will
1324 * set it up and, if valid, assign it to the session.
1325 */
1326 DBG("Tracing session %s created with ID %" PRIu64 " by uid = %d, gid = %d",
1327 new_session->name, new_session->id, new_session->uid,
1328 new_session->gid);
1329 ret_code = LTTNG_OK;
1330 end:
1331 if (new_session) {
1332 (void) session_get(new_session);
1333 *out_session = new_session;
1334 }
1335 return ret_code;
1336 error:
1337 session_put(new_session);
1338 new_session = NULL;
1339 goto end;
1340 }
1341
1342 /*
1343 * Check if the UID matches the session. Root user has access to all
1344 * sessions.
1345 */
1346 bool session_access_ok(struct ltt_session *session, uid_t uid)
1347 {
1348 LTTNG_ASSERT(session);
1349 return (uid == session->uid) || uid == 0;
1350 }
1351
1352 /*
1353 * Set a session's rotation state and reset all associated state.
1354 *
1355 * This function resets the rotation state (check timers, pending
1356 * flags, etc.) and sets the result of the last rotation. The result
1357 * can be queries by a liblttng-ctl client.
1358 *
1359 * Be careful of the result passed to this function. For instance,
1360 * on failure to launch a rotation, a client will expect the rotation
1361 * state to be set to "NO_ROTATION". If an error occurred while the
1362 * rotation was "ONGOING", result should be set to "ERROR", which will
1363 * allow a client to report it.
1364 *
1365 * Must be called with the session and session_list locks held.
1366 */
1367 int session_reset_rotation_state(struct ltt_session *session,
1368 enum lttng_rotation_state result)
1369 {
1370 int ret = 0;
1371
1372 ASSERT_LOCKED(ltt_session_list.lock);
1373 ASSERT_LOCKED(session->lock);
1374
1375 session->rotation_state = result;
1376 if (session->rotation_pending_check_timer_enabled) {
1377 ret = timer_session_rotation_pending_check_stop(session);
1378 }
1379 if (session->chunk_being_archived) {
1380 uint64_t chunk_id;
1381 enum lttng_trace_chunk_status chunk_status;
1382
1383 chunk_status = lttng_trace_chunk_get_id(
1384 session->chunk_being_archived,
1385 &chunk_id);
1386 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
1387 LTTNG_OPTIONAL_SET(&session->last_archived_chunk_id,
1388 chunk_id);
1389 lttng_trace_chunk_put(session->chunk_being_archived);
1390 session->chunk_being_archived = NULL;
1391 /*
1392 * Fire the clear reply notifiers if we are completing a clear
1393 * rotation.
1394 */
1395 session_notify_clear(session);
1396 }
1397 return ret;
1398 }
1399
1400 /*
1401 * Sample the id of a session looked up via its name.
1402 * Here the term "sampling" hint the caller that this return the id at a given
1403 * point in time with no guarantee that the session for which the id was
1404 * sampled still exist at that point.
1405 *
1406 * Return 0 when the session is not found,
1407 * Return 1 when the session is found and set `id`.
1408 */
1409 bool sample_session_id_by_name(const char *name, uint64_t *id)
1410 {
1411 bool found = false;
1412 struct lttng_ht_node_str *node;
1413 struct lttng_ht_iter iter;
1414 struct ltt_session *ls;
1415
1416 rcu_read_lock();
1417
1418 if (!ltt_sessions_ht_by_name) {
1419 found = false;
1420 goto end;
1421 }
1422
1423 lttng_ht_lookup(ltt_sessions_ht_by_name, name, &iter);
1424 node = lttng_ht_iter_get_node_str(&iter);
1425 if (node == NULL) {
1426 found = false;
1427 goto end;
1428 }
1429
1430 ls = caa_container_of(node, struct ltt_session, node_by_name);
1431 *id = ls->id;
1432 found = true;
1433
1434 DBG3("Session id `%" PRIu64 "` sampled for session `%s", *id, name);
1435 end:
1436 rcu_read_unlock();
1437 return found;
1438 }
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