trace-chunk: Introduce chunk "path", relayd session "ongoing_rotation", sessiond...
[lttng-tools.git] / src / bin / lttng-sessiond / session.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <limits.h>
20 #include <inttypes.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/stat.h>
25 #include <urcu.h>
26 #include <dirent.h>
27 #include <sys/types.h>
28 #include <pthread.h>
29
30 #include <common/common.h>
31 #include <common/utils.h>
32 #include <common/trace-chunk.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <lttng/location-internal.h>
35 #include "lttng-sessiond.h"
36 #include "kernel.h"
37
38 #include "session.h"
39 #include "utils.h"
40 #include "trace-ust.h"
41 #include "timer.h"
42 #include "cmd.h"
43
44 struct ltt_session_destroy_notifier_element {
45 ltt_session_destroy_notifier notifier;
46 void *user_data;
47 };
48
49 struct ltt_session_clear_notifier_element {
50 ltt_session_clear_notifier notifier;
51 void *user_data;
52 };
53
54 /*
55 * NOTES:
56 *
57 * No ltt_session.lock is taken here because those data structure are widely
58 * spread across the lttng-tools code base so before caling functions below
59 * that can read/write a session, the caller MUST acquire the session lock
60 * using session_lock() and session_unlock().
61 */
62
63 /*
64 * Init tracing session list.
65 *
66 * Please see session.h for more explanation and correct usage of the list.
67 */
68 static struct ltt_session_list ltt_session_list = {
69 .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
70 .lock = PTHREAD_MUTEX_INITIALIZER,
71 .removal_cond = PTHREAD_COND_INITIALIZER,
72 .next_uuid = 0,
73 };
74
75 /* These characters are forbidden in a session name. Used by validate_name. */
76 static const char *forbidden_name_chars = "/";
77
78 /* Global hash table to keep the sessions, indexed by id. */
79 static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
80
81 /*
82 * Validate the session name for forbidden characters.
83 *
84 * Return 0 on success else -1 meaning a forbidden char. has been found.
85 */
86 static int validate_name(const char *name)
87 {
88 int ret;
89 char *tok, *tmp_name;
90
91 assert(name);
92
93 tmp_name = strdup(name);
94 if (!tmp_name) {
95 /* ENOMEM here. */
96 ret = -1;
97 goto error;
98 }
99
100 tok = strpbrk(tmp_name, forbidden_name_chars);
101 if (tok) {
102 DBG("Session name %s contains a forbidden character", name);
103 /* Forbidden character has been found. */
104 ret = -1;
105 goto error;
106 }
107 ret = 0;
108
109 error:
110 free(tmp_name);
111 return ret;
112 }
113
114 /*
115 * Add a ltt_session structure to the global list.
116 *
117 * The caller MUST acquire the session list lock before.
118 * Returns the unique identifier for the session.
119 */
120 static uint64_t add_session_list(struct ltt_session *ls)
121 {
122 assert(ls);
123
124 cds_list_add(&ls->list, &ltt_session_list.head);
125 return ltt_session_list.next_uuid++;
126 }
127
128 /*
129 * Delete a ltt_session structure to the global list.
130 *
131 * The caller MUST acquire the session list lock before.
132 */
133 static void del_session_list(struct ltt_session *ls)
134 {
135 assert(ls);
136
137 cds_list_del(&ls->list);
138 }
139
140 /*
141 * Return a pointer to the session list.
142 */
143 struct ltt_session_list *session_get_list(void)
144 {
145 return &ltt_session_list;
146 }
147
148 /*
149 * Returns once the session list is empty.
150 */
151 void session_list_wait_empty(void)
152 {
153 pthread_mutex_lock(&ltt_session_list.lock);
154 while (!cds_list_empty(&ltt_session_list.head)) {
155 pthread_cond_wait(&ltt_session_list.removal_cond,
156 &ltt_session_list.lock);
157 }
158 pthread_mutex_unlock(&ltt_session_list.lock);
159 }
160
161 /*
162 * Acquire session list lock
163 */
164 void session_lock_list(void)
165 {
166 pthread_mutex_lock(&ltt_session_list.lock);
167 }
168
169 /*
170 * Try to acquire session list lock
171 */
172 int session_trylock_list(void)
173 {
174 return pthread_mutex_trylock(&ltt_session_list.lock);
175 }
176
177 /*
178 * Release session list lock
179 */
180 void session_unlock_list(void)
181 {
182 pthread_mutex_unlock(&ltt_session_list.lock);
183 }
184
185 /*
186 * Get the session's consumer destination type.
187 *
188 * The caller must hold the session lock.
189 */
190 enum consumer_dst_type session_get_consumer_destination_type(
191 const struct ltt_session *session)
192 {
193 /*
194 * The output information is duplicated in both of those session types.
195 * Hence, it doesn't matter from which it is retrieved. However, it is
196 * possible for only one of them to be set.
197 */
198 return session->kernel_session ?
199 session->kernel_session->consumer->type :
200 session->ust_session->consumer->type;
201 }
202
203 /*
204 * Get the session's consumer network hostname.
205 * The caller must ensure that the destination is of type "net".
206 *
207 * The caller must hold the session lock.
208 */
209 const char *session_get_net_consumer_hostname(const struct ltt_session *session)
210 {
211 const char *hostname = NULL;
212 const struct consumer_output *output;
213
214 output = session->kernel_session ?
215 session->kernel_session->consumer :
216 session->ust_session->consumer;
217
218 /*
219 * hostname is assumed to be the same for both control and data
220 * connections.
221 */
222 switch (output->dst.net.control.dtype) {
223 case LTTNG_DST_IPV4:
224 hostname = output->dst.net.control.dst.ipv4;
225 break;
226 case LTTNG_DST_IPV6:
227 hostname = output->dst.net.control.dst.ipv6;
228 break;
229 default:
230 abort();
231 }
232 return hostname;
233 }
234
235 /*
236 * Get the session's consumer network control and data ports.
237 * The caller must ensure that the destination is of type "net".
238 *
239 * The caller must hold the session lock.
240 */
241 void session_get_net_consumer_ports(const struct ltt_session *session,
242 uint16_t *control_port, uint16_t *data_port)
243 {
244 const struct consumer_output *output;
245
246 output = session->kernel_session ?
247 session->kernel_session->consumer :
248 session->ust_session->consumer;
249 *control_port = output->dst.net.control.port;
250 *data_port = output->dst.net.data.port;
251 }
252
253 /*
254 * Get the location of the latest trace archive produced by a rotation.
255 *
256 * The caller must hold the session lock.
257 */
258 struct lttng_trace_archive_location *session_get_trace_archive_location(
259 const struct ltt_session *session)
260 {
261 int ret;
262 struct lttng_trace_archive_location *location = NULL;
263 char *chunk_path = NULL;
264
265 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED ||
266 !session->last_archived_chunk_name) {
267 goto end;
268 }
269
270 switch (session_get_consumer_destination_type(session)) {
271 case CONSUMER_DST_LOCAL:
272 ret = asprintf(&chunk_path,
273 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
274 session_get_base_path(session),
275 session->last_archived_chunk_name);
276 if (ret == -1) {
277 goto end;
278 }
279 location = lttng_trace_archive_location_local_create(
280 chunk_path);
281 break;
282 case CONSUMER_DST_NET:
283 {
284 const char *hostname;
285 uint16_t control_port, data_port;
286
287 hostname = session_get_net_consumer_hostname(session);
288 session_get_net_consumer_ports(session,
289 &control_port,
290 &data_port);
291 location = lttng_trace_archive_location_relay_create(
292 hostname,
293 LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
294 control_port, data_port, session->last_chunk_path);
295 break;
296 }
297 default:
298 abort();
299 }
300 end:
301 free(chunk_path);
302 return location;
303 }
304
305 /*
306 * Allocate the ltt_sessions_ht_by_id HT.
307 *
308 * The session list lock must be held.
309 */
310 static int ltt_sessions_ht_alloc(void)
311 {
312 int ret = 0;
313
314 DBG("Allocating ltt_sessions_ht_by_id");
315 ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
316 if (!ltt_sessions_ht_by_id) {
317 ret = -1;
318 ERR("Failed to allocate ltt_sessions_ht_by_id");
319 goto end;
320 }
321 end:
322 return ret;
323 }
324
325 /*
326 * Destroy the ltt_sessions_ht_by_id HT.
327 *
328 * The session list lock must be held.
329 */
330 static void ltt_sessions_ht_destroy(void)
331 {
332 if (!ltt_sessions_ht_by_id) {
333 return;
334 }
335 ht_cleanup_push(ltt_sessions_ht_by_id);
336 ltt_sessions_ht_by_id = NULL;
337 }
338
339 /*
340 * Add a ltt_session to the ltt_sessions_ht_by_id.
341 * If unallocated, the ltt_sessions_ht_by_id HT is allocated.
342 * The session list lock must be held.
343 */
344 static void add_session_ht(struct ltt_session *ls)
345 {
346 int ret;
347
348 assert(ls);
349
350 if (!ltt_sessions_ht_by_id) {
351 ret = ltt_sessions_ht_alloc();
352 if (ret) {
353 ERR("Error allocating the sessions HT");
354 goto end;
355 }
356 }
357 lttng_ht_node_init_u64(&ls->node, ls->id);
358 lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node);
359
360 end:
361 return;
362 }
363
364 /*
365 * Test if ltt_sessions_ht_by_id is empty.
366 * Return 1 if empty, 0 if not empty.
367 * The session list lock must be held.
368 */
369 static int ltt_sessions_ht_empty(void)
370 {
371 int ret;
372
373 if (!ltt_sessions_ht_by_id) {
374 ret = 1;
375 goto end;
376 }
377
378 ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1;
379 end:
380 return ret;
381 }
382
383 /*
384 * Remove a ltt_session from the ltt_sessions_ht_by_id.
385 * If empty, the ltt_sessions_ht_by_id HT is freed.
386 * The session list lock must be held.
387 */
388 static void del_session_ht(struct ltt_session *ls)
389 {
390 struct lttng_ht_iter iter;
391 int ret;
392
393 assert(ls);
394 assert(ltt_sessions_ht_by_id);
395
396 iter.iter.node = &ls->node.node;
397 ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter);
398 assert(!ret);
399
400 if (ltt_sessions_ht_empty()) {
401 DBG("Empty ltt_sessions_ht_by_id, destroying it");
402 ltt_sessions_ht_destroy();
403 }
404 }
405
406 /*
407 * Acquire session lock
408 */
409 void session_lock(struct ltt_session *session)
410 {
411 assert(session);
412
413 pthread_mutex_lock(&session->lock);
414 }
415
416 /*
417 * Release session lock
418 */
419 void session_unlock(struct ltt_session *session)
420 {
421 assert(session);
422
423 pthread_mutex_unlock(&session->lock);
424 }
425
426 static
427 int _session_set_trace_chunk_no_lock_check(struct ltt_session *session,
428 struct lttng_trace_chunk *new_trace_chunk,
429 struct lttng_trace_chunk **_current_trace_chunk)
430 {
431 int ret = 0;
432 unsigned int i, refs_to_acquire = 0, refs_acquired = 0, refs_to_release = 0;
433 struct cds_lfht_iter iter;
434 struct consumer_socket *socket;
435 struct lttng_trace_chunk *current_trace_chunk;
436 uint64_t chunk_id;
437 enum lttng_trace_chunk_status chunk_status;
438
439 rcu_read_lock();
440 /*
441 * Ownership of current trace chunk is transferred to
442 * `current_trace_chunk`.
443 */
444 current_trace_chunk = session->current_trace_chunk;
445 session->current_trace_chunk = NULL;
446 if (session->ust_session) {
447 lttng_trace_chunk_put(
448 session->ust_session->current_trace_chunk);
449 session->ust_session->current_trace_chunk = NULL;
450 }
451 if (session->kernel_session) {
452 lttng_trace_chunk_put(
453 session->kernel_session->current_trace_chunk);
454 session->kernel_session->current_trace_chunk = NULL;
455 }
456 if (!new_trace_chunk) {
457 ret = 0;
458 goto end;
459 }
460 chunk_status = lttng_trace_chunk_get_id(new_trace_chunk, &chunk_id);
461 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
462
463 refs_to_acquire = 1;
464 refs_to_acquire += !!session->ust_session;
465 refs_to_acquire += !!session->kernel_session;
466
467 for (refs_acquired = 0; refs_acquired < refs_to_acquire;
468 refs_acquired++) {
469 if (!lttng_trace_chunk_get(new_trace_chunk)) {
470 ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
471 session->name);
472 goto error;
473 }
474 }
475
476 if (session->ust_session) {
477 const uint64_t relayd_id =
478 session->ust_session->consumer->net_seq_index;
479 const bool is_local_trace =
480 session->ust_session->consumer->type ==
481 CONSUMER_DST_LOCAL;
482
483 session->ust_session->current_trace_chunk = new_trace_chunk;
484 if (is_local_trace) {
485 enum lttng_error_code ret_error_code;
486
487 ret_error_code = ust_app_create_channel_subdirectories(
488 session->ust_session);
489 if (ret_error_code != LTTNG_OK) {
490 goto error;
491 }
492 }
493 cds_lfht_for_each_entry(
494 session->ust_session->consumer->socks->ht,
495 &iter, socket, node.node) {
496 pthread_mutex_lock(socket->lock);
497 ret = consumer_create_trace_chunk(socket,
498 relayd_id,
499 session->id, new_trace_chunk,
500 DEFAULT_UST_TRACE_DIR);
501 pthread_mutex_unlock(socket->lock);
502 if (ret) {
503 goto error;
504 }
505 }
506 }
507 if (session->kernel_session) {
508 const uint64_t relayd_id =
509 session->kernel_session->consumer->net_seq_index;
510 const bool is_local_trace =
511 session->kernel_session->consumer->type ==
512 CONSUMER_DST_LOCAL;
513
514 session->kernel_session->current_trace_chunk = new_trace_chunk;
515 if (is_local_trace) {
516 enum lttng_error_code ret_error_code;
517
518 ret_error_code = kernel_create_channel_subdirectories(
519 session->kernel_session);
520 if (ret_error_code != LTTNG_OK) {
521 goto error;
522 }
523 }
524 cds_lfht_for_each_entry(
525 session->kernel_session->consumer->socks->ht,
526 &iter, socket, node.node) {
527 pthread_mutex_lock(socket->lock);
528 ret = consumer_create_trace_chunk(socket,
529 relayd_id,
530 session->id, new_trace_chunk,
531 DEFAULT_KERNEL_TRACE_DIR);
532 pthread_mutex_unlock(socket->lock);
533 if (ret) {
534 goto error;
535 }
536 }
537 }
538
539 /*
540 * Update local current trace chunk state last, only if all remote
541 * creations succeeded.
542 */
543 session->current_trace_chunk = new_trace_chunk;
544 LTTNG_OPTIONAL_SET(&session->most_recent_chunk_id, chunk_id);
545 end:
546 if (_current_trace_chunk) {
547 *_current_trace_chunk = current_trace_chunk;
548 current_trace_chunk = NULL;
549 }
550 end_no_move:
551 rcu_read_unlock();
552 lttng_trace_chunk_put(current_trace_chunk);
553 return ret;
554 error:
555 if (session->ust_session) {
556 session->ust_session->current_trace_chunk = NULL;
557 }
558 if (session->kernel_session) {
559 session->kernel_session->current_trace_chunk = NULL;
560 }
561 /*
562 * Release references taken in the case where all references could not
563 * be acquired.
564 */
565 refs_to_release = refs_to_acquire - refs_acquired;
566 for (i = 0; i < refs_to_release; i++) {
567 lttng_trace_chunk_put(new_trace_chunk);
568 }
569 ret = -1;
570 goto end_no_move;
571 }
572
573 struct lttng_trace_chunk *session_create_new_trace_chunk(
574 const struct ltt_session *session,
575 const struct consumer_output *consumer_output_override,
576 const char *session_base_path_override,
577 const char *chunk_name_override)
578 {
579 int ret;
580 struct lttng_trace_chunk *trace_chunk = NULL;
581 enum lttng_trace_chunk_status chunk_status;
582 const time_t chunk_creation_ts = time(NULL);
583 bool is_local_trace;
584 const char *base_path;
585 struct lttng_directory_handle *session_output_directory = NULL;
586 const struct lttng_credentials session_credentials = {
587 .uid = session->uid,
588 .gid = session->gid,
589 };
590 uint64_t next_chunk_id;
591 const struct consumer_output *output;
592 const char *new_path;
593
594 if (consumer_output_override) {
595 output = consumer_output_override;
596 } else {
597 assert(session->ust_session || session->kernel_session);
598 output = session->ust_session ?
599 session->ust_session->consumer :
600 session->kernel_session->consumer;
601 }
602
603 is_local_trace = output->type == CONSUMER_DST_LOCAL;
604 base_path = session_base_path_override ? :
605 consumer_output_get_base_path(output);
606
607 if (chunk_creation_ts == (time_t) -1) {
608 PERROR("Failed to sample time while creation session \"%s\" trace chunk",
609 session->name);
610 goto error;
611 }
612
613 next_chunk_id = session->most_recent_chunk_id.is_set ?
614 session->most_recent_chunk_id.value + 1 : 0;
615
616 if (session->current_trace_chunk &&
617 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
618 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
619 DEFAULT_CHUNK_TMP_OLD_DIRECTORY);
620 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
621 goto error;
622 }
623 }
624 if (!session->current_trace_chunk) {
625 if (!session->rotated) {
626 new_path = "";
627 } else {
628 new_path = NULL;
629 }
630 } else {
631 new_path = DEFAULT_CHUNK_TMP_NEW_DIRECTORY;
632 }
633
634 trace_chunk = lttng_trace_chunk_create(next_chunk_id,
635 chunk_creation_ts, new_path);
636 if (!trace_chunk) {
637 goto error;
638 }
639
640 if (chunk_name_override) {
641 chunk_status = lttng_trace_chunk_override_name(trace_chunk,
642 chunk_name_override);
643 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
644 goto error;
645 }
646 }
647
648 if (!is_local_trace) {
649 /*
650 * No need to set crendentials and output directory
651 * for remote trace chunks.
652 */
653 goto end;
654 }
655
656 chunk_status = lttng_trace_chunk_set_credentials(trace_chunk,
657 &session_credentials);
658 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
659 goto error;
660 }
661
662 DBG("Creating base output directory of session \"%s\" at %s",
663 session->name, base_path);
664 ret = utils_mkdir_recursive(base_path, S_IRWXU | S_IRWXG,
665 session->uid, session->gid);
666 if (ret) {
667 goto error;
668 }
669 session_output_directory = lttng_directory_handle_create(base_path);
670 if (!session_output_directory) {
671 goto error;
672 }
673 chunk_status = lttng_trace_chunk_set_as_owner(trace_chunk,
674 session_output_directory);
675 lttng_directory_handle_put(session_output_directory);
676 session_output_directory = NULL;
677 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
678 goto error;
679 }
680 end:
681 return trace_chunk;
682 error:
683 lttng_directory_handle_put(session_output_directory);
684 lttng_trace_chunk_put(trace_chunk);
685 trace_chunk = NULL;
686 goto end;
687 }
688
689 int session_close_trace_chunk(struct ltt_session *session,
690 struct lttng_trace_chunk *trace_chunk,
691 enum lttng_trace_chunk_command_type close_command,
692 char *closed_trace_chunk_path)
693 {
694 int ret = 0;
695 bool error_occurred = false;
696 struct cds_lfht_iter iter;
697 struct consumer_socket *socket;
698 enum lttng_trace_chunk_status chunk_status;
699 const time_t chunk_close_timestamp = time(NULL);
700 const char *new_path;
701
702 chunk_status = lttng_trace_chunk_set_close_command(
703 trace_chunk, close_command);
704 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
705 ret = -1;
706 goto end;
707 }
708
709 if (chunk_close_timestamp == (time_t) -1) {
710 ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
711 session->name);
712 ret = -1;
713 goto end;
714 }
715
716 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE && !session->rotated) {
717 /* New chunk stays in session output directory. */
718 new_path = "";
719 } else {
720 /* Use chunk name for new chunk. */
721 new_path = NULL;
722 }
723 if (session->current_trace_chunk &&
724 !lttng_trace_chunk_get_name_overridden(session->current_trace_chunk)) {
725 /* Rename new chunk path. */
726 chunk_status = lttng_trace_chunk_rename_path(session->current_trace_chunk,
727 new_path);
728 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
729 ret = -1;
730 goto end;
731 }
732 }
733 if (!lttng_trace_chunk_get_name_overridden(trace_chunk) &&
734 close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION) {
735 const char *old_path;
736
737 if (!session->rotated) {
738 old_path = "";
739 } else {
740 old_path = NULL;
741 }
742 /* We need to move back the .tmp_old_chunk to its rightful place. */
743 chunk_status = lttng_trace_chunk_rename_path(trace_chunk,
744 old_path);
745 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
746 ret = -1;
747 goto end;
748 }
749 }
750 if (close_command == LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED) {
751 session->rotated = true;
752 }
753 chunk_status = lttng_trace_chunk_set_close_timestamp(trace_chunk,
754 chunk_close_timestamp);
755 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
756 ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
757 session->name);
758 ret = -1;
759 goto end;
760 }
761
762 if (session->ust_session) {
763 const uint64_t relayd_id =
764 session->ust_session->consumer->net_seq_index;
765
766 cds_lfht_for_each_entry(
767 session->ust_session->consumer->socks->ht,
768 &iter, socket, node.node) {
769 pthread_mutex_lock(socket->lock);
770 ret = consumer_close_trace_chunk(socket,
771 relayd_id,
772 session->id,
773 trace_chunk, closed_trace_chunk_path);
774 pthread_mutex_unlock(socket->lock);
775 if (ret) {
776 ERR("Failed to close trace chunk on user space consumer");
777 error_occurred = true;
778 }
779 }
780 }
781 if (session->kernel_session) {
782 const uint64_t relayd_id =
783 session->kernel_session->consumer->net_seq_index;
784
785 cds_lfht_for_each_entry(
786 session->kernel_session->consumer->socks->ht,
787 &iter, socket, node.node) {
788 pthread_mutex_lock(socket->lock);
789 ret = consumer_close_trace_chunk(socket,
790 relayd_id,
791 session->id,
792 trace_chunk, closed_trace_chunk_path);
793 pthread_mutex_unlock(socket->lock);
794 if (ret) {
795 ERR("Failed to close trace chunk on kernel consumer");
796 error_occurred = true;
797 }
798 }
799 }
800 ret = error_occurred ? -1 : 0;
801 end:
802 return ret;
803 }
804
805 /*
806 * Set a session's current trace chunk.
807 *
808 * Must be called with the session lock held.
809 */
810 int session_set_trace_chunk(struct ltt_session *session,
811 struct lttng_trace_chunk *new_trace_chunk,
812 struct lttng_trace_chunk **current_trace_chunk)
813 {
814 ASSERT_LOCKED(session->lock);
815 return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk,
816 current_trace_chunk);
817 }
818
819 static
820 void session_notify_destruction(const struct ltt_session *session)
821 {
822 size_t i;
823 const size_t count = lttng_dynamic_array_get_count(
824 &session->destroy_notifiers);
825
826 for (i = 0; i < count; i++) {
827 const struct ltt_session_destroy_notifier_element *element =
828 lttng_dynamic_array_get_element(
829 &session->destroy_notifiers, i);
830
831 element->notifier(session, element->user_data);
832 }
833 }
834
835 /*
836 * Fire each clear notifier once, and remove them from the array.
837 */
838 void session_notify_clear(struct ltt_session *session)
839 {
840 size_t i;
841 const size_t count = lttng_dynamic_array_get_count(
842 &session->clear_notifiers);
843
844 for (i = 0; i < count; i++) {
845 const struct ltt_session_clear_notifier_element *element =
846 lttng_dynamic_array_get_element(
847 &session->clear_notifiers, i);
848
849 element->notifier(session, element->user_data);
850 }
851 lttng_dynamic_array_clear(&session->clear_notifiers);
852 }
853
854 static
855 void session_release(struct urcu_ref *ref)
856 {
857 int ret;
858 struct ltt_ust_session *usess;
859 struct ltt_kernel_session *ksess;
860 struct ltt_session *session = container_of(ref, typeof(*session), ref);
861 const bool session_published = session->published;
862
863 assert(!session->chunk_being_archived);
864
865 usess = session->ust_session;
866 ksess = session->kernel_session;
867
868 /* Clean kernel session teardown, keeping data for destroy notifier. */
869 kernel_destroy_session(ksess);
870
871 /* UST session teardown, keeping data for destroy notifier. */
872 if (usess) {
873 /* Close any relayd session */
874 consumer_output_send_destroy_relayd(usess->consumer);
875
876 /* Destroy every UST application related to this session. */
877 ret = ust_app_destroy_trace_all(usess);
878 if (ret) {
879 ERR("Error in ust_app_destroy_trace_all");
880 }
881
882 /* Clean up the rest, keeping destroy notifier data. */
883 trace_ust_destroy_session(usess);
884 }
885
886 /*
887 * Must notify the kernel thread here to update it's poll set in order to
888 * remove the channel(s)' fd just destroyed.
889 */
890 ret = notify_thread_pipe(kernel_poll_pipe[1]);
891 if (ret < 0) {
892 PERROR("write kernel poll pipe");
893 }
894
895 DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
896
897 snapshot_destroy(&session->snapshot);
898
899 pthread_mutex_destroy(&session->lock);
900
901 if (session_published) {
902 ASSERT_LOCKED(ltt_session_list.lock);
903 del_session_list(session);
904 del_session_ht(session);
905 }
906 session_notify_destruction(session);
907
908 consumer_output_put(session->consumer);
909 kernel_free_session(ksess);
910 session->kernel_session = NULL;
911 if (usess) {
912 trace_ust_free_session(usess);
913 session->ust_session = NULL;
914 }
915 lttng_dynamic_array_reset(&session->destroy_notifiers);
916 lttng_dynamic_array_reset(&session->clear_notifiers);
917 free(session->last_archived_chunk_name);
918 free(session->base_path);
919 free(session);
920 if (session_published) {
921 /*
922 * Broadcast after free-ing to ensure the memory is
923 * reclaimed before the main thread exits.
924 */
925 pthread_cond_broadcast(&ltt_session_list.removal_cond);
926 }
927 }
928
929 /*
930 * Acquire a reference to a session.
931 * This function may fail (return false); its return value must be checked.
932 */
933 bool session_get(struct ltt_session *session)
934 {
935 return urcu_ref_get_unless_zero(&session->ref);
936 }
937
938 /*
939 * Release a reference to a session.
940 */
941 void session_put(struct ltt_session *session)
942 {
943 if (!session) {
944 return;
945 }
946 /*
947 * The session list lock must be held as any session_put()
948 * may cause the removal of the session from the session_list.
949 */
950 ASSERT_LOCKED(ltt_session_list.lock);
951 assert(session->ref.refcount);
952 urcu_ref_put(&session->ref, session_release);
953 }
954
955 /*
956 * Destroy a session.
957 *
958 * This method does not immediately release/free the session as other
959 * components may still hold a reference to the session. However,
960 * the session should no longer be presented to the user.
961 *
962 * Releases the session list's reference to the session
963 * and marks it as destroyed. Iterations on the session list should be
964 * mindful of the "destroyed" flag.
965 */
966 void session_destroy(struct ltt_session *session)
967 {
968 assert(!session->destroyed);
969 session->destroyed = true;
970 session_put(session);
971 }
972
973 int session_add_destroy_notifier(struct ltt_session *session,
974 ltt_session_destroy_notifier notifier, void *user_data)
975 {
976 const struct ltt_session_destroy_notifier_element element = {
977 .notifier = notifier,
978 .user_data = user_data
979 };
980
981 return lttng_dynamic_array_add_element(&session->destroy_notifiers,
982 &element);
983 }
984
985 int session_add_clear_notifier(struct ltt_session *session,
986 ltt_session_clear_notifier notifier, void *user_data)
987 {
988 const struct ltt_session_clear_notifier_element element = {
989 .notifier = notifier,
990 .user_data = user_data
991 };
992
993 return lttng_dynamic_array_add_element(&session->clear_notifiers,
994 &element);
995 }
996
997 /*
998 * Return a ltt_session structure ptr that matches name. If no session found,
999 * NULL is returned. This must be called with the session list lock held using
1000 * session_lock_list and session_unlock_list.
1001 * A reference to the session is implicitly acquired by this function.
1002 */
1003 struct ltt_session *session_find_by_name(const char *name)
1004 {
1005 struct ltt_session *iter;
1006
1007 assert(name);
1008 ASSERT_LOCKED(ltt_session_list.lock);
1009
1010 DBG2("Trying to find session by name %s", name);
1011
1012 cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
1013 if (!strncmp(iter->name, name, NAME_MAX) &&
1014 !iter->destroyed) {
1015 goto found;
1016 }
1017 }
1018
1019 return NULL;
1020 found:
1021 return session_get(iter) ? iter : NULL;
1022 }
1023
1024 /*
1025 * Return an ltt_session that matches the id. If no session is found,
1026 * NULL is returned. This must be called with rcu_read_lock and
1027 * session list lock held (to guarantee the lifetime of the session).
1028 */
1029 struct ltt_session *session_find_by_id(uint64_t id)
1030 {
1031 struct lttng_ht_node_u64 *node;
1032 struct lttng_ht_iter iter;
1033 struct ltt_session *ls;
1034
1035 ASSERT_LOCKED(ltt_session_list.lock);
1036
1037 if (!ltt_sessions_ht_by_id) {
1038 goto end;
1039 }
1040
1041 lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
1042 node = lttng_ht_iter_get_node_u64(&iter);
1043 if (node == NULL) {
1044 goto end;
1045 }
1046 ls = caa_container_of(node, struct ltt_session, node);
1047
1048 DBG3("Session %" PRIu64 " found by id.", id);
1049 return session_get(ls) ? ls : NULL;
1050
1051 end:
1052 DBG3("Session %" PRIu64 " NOT found by id", id);
1053 return NULL;
1054 }
1055
1056 /*
1057 * Create a new session and add it to the session list.
1058 * Session list lock must be held by the caller.
1059 */
1060 enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
1061 struct ltt_session **out_session)
1062 {
1063 int ret;
1064 enum lttng_error_code ret_code;
1065 struct ltt_session *new_session = NULL;
1066
1067 ASSERT_LOCKED(ltt_session_list.lock);
1068 if (name) {
1069 struct ltt_session *clashing_session;
1070
1071 clashing_session = session_find_by_name(name);
1072 if (clashing_session) {
1073 session_put(clashing_session);
1074 ret_code = LTTNG_ERR_EXIST_SESS;
1075 goto error;
1076 }
1077 }
1078 new_session = zmalloc(sizeof(struct ltt_session));
1079 if (!new_session) {
1080 PERROR("Failed to allocate an ltt_session structure");
1081 ret_code = LTTNG_ERR_NOMEM;
1082 goto error;
1083 }
1084
1085 lttng_dynamic_array_init(&new_session->destroy_notifiers,
1086 sizeof(struct ltt_session_destroy_notifier_element),
1087 NULL);
1088 lttng_dynamic_array_init(&new_session->clear_notifiers,
1089 sizeof(struct ltt_session_clear_notifier_element),
1090 NULL);
1091 urcu_ref_init(&new_session->ref);
1092 pthread_mutex_init(&new_session->lock, NULL);
1093
1094 new_session->creation_time = time(NULL);
1095 if (new_session->creation_time == (time_t) -1) {
1096 PERROR("Failed to sample session creation time");
1097 ret_code = LTTNG_ERR_SESSION_FAIL;
1098 goto error;
1099 }
1100
1101 /* Create default consumer output. */
1102 new_session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1103 if (new_session->consumer == NULL) {
1104 ret_code = LTTNG_ERR_NOMEM;
1105 goto error;
1106 }
1107
1108 if (name) {
1109 ret = lttng_strncpy(new_session->name, name, sizeof(new_session->name));
1110 if (ret) {
1111 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1112 goto error;
1113 }
1114 ret = validate_name(name);
1115 if (ret < 0) {
1116 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1117 goto error;
1118 }
1119 } else {
1120 int i = 0;
1121 bool found_name = false;
1122 char datetime[16];
1123 struct tm *timeinfo;
1124
1125 timeinfo = localtime(&new_session->creation_time);
1126 if (!timeinfo) {
1127 ret_code = LTTNG_ERR_SESSION_FAIL;
1128 goto error;
1129 }
1130 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1131 for (i = 0; i < INT_MAX; i++) {
1132 struct ltt_session *clashing_session;
1133
1134 if (i == 0) {
1135 ret = snprintf(new_session->name,
1136 sizeof(new_session->name),
1137 "%s-%s",
1138 DEFAULT_SESSION_NAME,
1139 datetime);
1140 } else {
1141 ret = snprintf(new_session->name,
1142 sizeof(new_session->name),
1143 "%s%d-%s",
1144 DEFAULT_SESSION_NAME, i,
1145 datetime);
1146 }
1147 new_session->name_contains_creation_time = true;
1148 if (ret == -1 || ret >= sizeof(new_session->name)) {
1149 /*
1150 * Null-terminate in case the name is used
1151 * in logging statements.
1152 */
1153 new_session->name[sizeof(new_session->name) - 1] = '\0';
1154 ret_code = LTTNG_ERR_SESSION_FAIL;
1155 goto error;
1156 }
1157
1158 clashing_session =
1159 session_find_by_name(new_session->name);
1160 session_put(clashing_session);
1161 if (!clashing_session) {
1162 found_name = true;
1163 break;
1164 }
1165 }
1166 if (found_name) {
1167 DBG("Generated session name \"%s\"", new_session->name);
1168 new_session->has_auto_generated_name = true;
1169 } else {
1170 ERR("Failed to auto-generate a session name");
1171 ret_code = LTTNG_ERR_SESSION_FAIL;
1172 goto error;
1173 }
1174 }
1175
1176 ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
1177 if (ret < 0) {
1178 if (errno == ENAMETOOLONG) {
1179 new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
1180 ERR("Hostname exceeds the maximal permitted length and has been truncated to %s",
1181 new_session->hostname);
1182 } else {
1183 ret_code = LTTNG_ERR_SESSION_FAIL;
1184 goto error;
1185 }
1186 }
1187
1188 new_session->uid = uid;
1189 new_session->gid = gid;
1190
1191 ret = snapshot_init(&new_session->snapshot);
1192 if (ret < 0) {
1193 ret_code = LTTNG_ERR_NOMEM;
1194 goto error;
1195 }
1196
1197 new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
1198
1199 /* Add new session to the session list. */
1200 new_session->id = add_session_list(new_session);
1201
1202 /*
1203 * Add the new session to the ltt_sessions_ht_by_id.
1204 * No ownership is taken by the hash table; it is merely
1205 * a wrapper around the session list used for faster access
1206 * by session id.
1207 */
1208 add_session_ht(new_session);
1209 new_session->published = true;
1210
1211 /*
1212 * Consumer is left to NULL since the create_session_uri command will
1213 * set it up and, if valid, assign it to the session.
1214 */
1215 DBG("Tracing session %s created with ID %" PRIu64 " by uid = %d, gid = %d",
1216 new_session->name, new_session->id, new_session->uid,
1217 new_session->gid);
1218 ret_code = LTTNG_OK;
1219 end:
1220 if (new_session) {
1221 (void) session_get(new_session);
1222 *out_session = new_session;
1223 }
1224 return ret_code;
1225 error:
1226 session_put(new_session);
1227 new_session = NULL;
1228 goto end;
1229 }
1230
1231 /*
1232 * Check if the UID or GID match the session. Root user has access to all
1233 * sessions.
1234 */
1235 int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
1236 {
1237 assert(session);
1238
1239 if (uid != session->uid && gid != session->gid && uid != 0) {
1240 return 0;
1241 } else {
1242 return 1;
1243 }
1244 }
1245
1246 /*
1247 * Set a session's rotation state and reset all associated state.
1248 *
1249 * This function resets the rotation state (check timers, pending
1250 * flags, etc.) and sets the result of the last rotation. The result
1251 * can be queries by a liblttng-ctl client.
1252 *
1253 * Be careful of the result passed to this function. For instance,
1254 * on failure to launch a rotation, a client will expect the rotation
1255 * state to be set to "NO_ROTATION". If an error occurred while the
1256 * rotation was "ONGOING", result should be set to "ERROR", which will
1257 * allow a client to report it.
1258 *
1259 * Must be called with the session and session_list locks held.
1260 */
1261 int session_reset_rotation_state(struct ltt_session *session,
1262 enum lttng_rotation_state result)
1263 {
1264 int ret = 0;
1265
1266 ASSERT_LOCKED(ltt_session_list.lock);
1267 ASSERT_LOCKED(session->lock);
1268
1269 session->rotation_state = result;
1270 if (session->rotation_pending_check_timer_enabled) {
1271 ret = timer_session_rotation_pending_check_stop(session);
1272 }
1273 if (session->chunk_being_archived) {
1274 uint64_t chunk_id;
1275 enum lttng_trace_chunk_status chunk_status;
1276
1277 chunk_status = lttng_trace_chunk_get_id(
1278 session->chunk_being_archived,
1279 &chunk_id);
1280 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
1281 LTTNG_OPTIONAL_SET(&session->last_archived_chunk_id,
1282 chunk_id);
1283 lttng_trace_chunk_put(session->chunk_being_archived);
1284 session->chunk_being_archived = NULL;
1285 /*
1286 * Fire the clear reply notifiers if we are completing a clear
1287 * rotation.
1288 */
1289 session_notify_clear(session);
1290 }
1291 return ret;
1292 }
This page took 0.093528 seconds and 4 git commands to generate.