Clean-up: remove dead assignments while setting session trace chunk
[lttng-tools.git] / src / bin / lttng-sessiond / session.c
CommitLineData
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1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
d14d33bf
AM
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.
91d76f53 7 *
5b74c7b1
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8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
d14d33bf 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
5b74c7b1
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11 * GNU General Public License for more details.
12 *
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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.
5b74c7b1
DG
16 */
17
6c1c0768 18#define _LGPL_SOURCE
6c9cc2ab 19#include <limits.h>
d022620a 20#include <inttypes.h>
5b74c7b1
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21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
a304c14c 24#include <sys/stat.h>
f6a9efaa 25#include <urcu.h>
3d071855
MD
26#include <dirent.h>
27#include <sys/types.h>
99d688f2 28#include <pthread.h>
5b74c7b1 29
990570ed 30#include <common/common.h>
82b69413
JG
31#include <common/utils.h>
32#include <common/trace-chunk.h>
db758600 33#include <common/sessiond-comm/sessiond-comm.h>
5d65beab 34#include <lttng/location-internal.h>
e32d7f27
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35#include "lttng-sessiond.h"
36#include "kernel.h"
1e307fab 37
5b74c7b1 38#include "session.h"
23324029 39#include "utils.h"
dd73d57b 40#include "trace-ust.h"
a7333da7 41#include "timer.h"
7fdbed1c 42#include "cmd.h"
5b74c7b1 43
3e3665b8
JG
44struct ltt_session_destroy_notifier_element {
45 ltt_session_destroy_notifier notifier;
46 void *user_data;
47};
48
8c0faa1d 49/*
b5541356 50 * NOTES:
8c0faa1d 51 *
b5541356
DG
52 * No ltt_session.lock is taken here because those data structure are widely
53 * spread across the lttng-tools code base so before caling functions below
54 * that can read/write a session, the caller MUST acquire the session lock
54d01ffb 55 * using session_lock() and session_unlock().
8c0faa1d 56 */
8c0faa1d 57
5b74c7b1 58/*
b5541356 59 * Init tracing session list.
5b74c7b1 60 *
b5541356 61 * Please see session.h for more explanation and correct usage of the list.
5b74c7b1 62 */
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DG
63static struct ltt_session_list ltt_session_list = {
64 .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
65 .lock = PTHREAD_MUTEX_INITIALIZER,
99d688f2 66 .removal_cond = PTHREAD_COND_INITIALIZER,
a24f7994 67 .next_uuid = 0,
b5541356 68};
5b74c7b1 69
1c1c3634
DG
70/* These characters are forbidden in a session name. Used by validate_name. */
71static const char *forbidden_name_chars = "/";
72
23324029
JD
73/* Global hash table to keep the sessions, indexed by id. */
74static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
75
1c1c3634
DG
76/*
77 * Validate the session name for forbidden characters.
78 *
79 * Return 0 on success else -1 meaning a forbidden char. has been found.
80 */
81static int validate_name(const char *name)
82{
83 int ret;
84 char *tok, *tmp_name;
85
86 assert(name);
87
88 tmp_name = strdup(name);
89 if (!tmp_name) {
90 /* ENOMEM here. */
91 ret = -1;
92 goto error;
93 }
94
95 tok = strpbrk(tmp_name, forbidden_name_chars);
96 if (tok) {
97 DBG("Session name %s contains a forbidden character", name);
98 /* Forbidden character has been found. */
99 ret = -1;
100 goto error;
101 }
102 ret = 0;
103
104error:
105 free(tmp_name);
106 return ret;
107}
108
5b74c7b1 109/*
050349bb 110 * Add a ltt_session structure to the global list.
5b74c7b1 111 *
050349bb 112 * The caller MUST acquire the session list lock before.
44e96653 113 * Returns the unique identifier for the session.
5b74c7b1 114 */
d022620a 115static uint64_t add_session_list(struct ltt_session *ls)
5b74c7b1 116{
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117 assert(ls);
118
5b74c7b1 119 cds_list_add(&ls->list, &ltt_session_list.head);
a24f7994 120 return ltt_session_list.next_uuid++;
5b74c7b1
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121}
122
123/*
050349bb 124 * Delete a ltt_session structure to the global list.
b5541356 125 *
050349bb 126 * The caller MUST acquire the session list lock before.
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127 */
128static void del_session_list(struct ltt_session *ls)
129{
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130 assert(ls);
131
5b74c7b1 132 cds_list_del(&ls->list);
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DG
133}
134
b5541356 135/*
050349bb 136 * Return a pointer to the session list.
b5541356 137 */
54d01ffb 138struct ltt_session_list *session_get_list(void)
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DG
139{
140 return &ltt_session_list;
141}
142
99d688f2
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143/*
144 * Returns once the session list is empty.
145 */
146void session_list_wait_empty(void)
147{
148 pthread_mutex_lock(&ltt_session_list.lock);
149 while (!cds_list_empty(&ltt_session_list.head)) {
150 pthread_cond_wait(&ltt_session_list.removal_cond,
151 &ltt_session_list.lock);
152 }
153 pthread_mutex_unlock(&ltt_session_list.lock);
154}
155
b5541356 156/*
6c9cc2ab 157 * Acquire session list lock
b5541356 158 */
54d01ffb 159void session_lock_list(void)
b5541356 160{
6c9cc2ab 161 pthread_mutex_lock(&ltt_session_list.lock);
b5541356
DG
162}
163
71e0a100
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164/*
165 * Try to acquire session list lock
166 */
167int session_trylock_list(void)
168{
169 return pthread_mutex_trylock(&ltt_session_list.lock);
170}
171
b5541356 172/*
6c9cc2ab 173 * Release session list lock
b5541356 174 */
54d01ffb 175void session_unlock_list(void)
b5541356 176{
6c9cc2ab 177 pthread_mutex_unlock(&ltt_session_list.lock);
b5541356
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178}
179
dd73d57b
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180/*
181 * Get the session's consumer destination type.
182 *
183 * The caller must hold the session lock.
184 */
185enum consumer_dst_type session_get_consumer_destination_type(
186 const struct ltt_session *session)
187{
188 /*
189 * The output information is duplicated in both of those session types.
190 * Hence, it doesn't matter from which it is retrieved. However, it is
191 * possible for only one of them to be set.
192 */
193 return session->kernel_session ?
194 session->kernel_session->consumer->type :
195 session->ust_session->consumer->type;
196}
197
198/*
199 * Get the session's consumer network hostname.
200 * The caller must ensure that the destination is of type "net".
201 *
202 * The caller must hold the session lock.
203 */
204const char *session_get_net_consumer_hostname(const struct ltt_session *session)
205{
206 const char *hostname = NULL;
207 const struct consumer_output *output;
208
209 output = session->kernel_session ?
210 session->kernel_session->consumer :
211 session->ust_session->consumer;
212
213 /*
214 * hostname is assumed to be the same for both control and data
215 * connections.
216 */
217 switch (output->dst.net.control.dtype) {
218 case LTTNG_DST_IPV4:
219 hostname = output->dst.net.control.dst.ipv4;
220 break;
221 case LTTNG_DST_IPV6:
222 hostname = output->dst.net.control.dst.ipv6;
223 break;
224 default:
225 abort();
226 }
227 return hostname;
228}
229
230/*
231 * Get the session's consumer network control and data ports.
232 * The caller must ensure that the destination is of type "net".
233 *
234 * The caller must hold the session lock.
235 */
236void session_get_net_consumer_ports(const struct ltt_session *session,
237 uint16_t *control_port, uint16_t *data_port)
238{
239 const struct consumer_output *output;
240
241 output = session->kernel_session ?
242 session->kernel_session->consumer :
243 session->ust_session->consumer;
244 *control_port = output->dst.net.control.port;
245 *data_port = output->dst.net.data.port;
246}
247
5d65beab
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248/*
249 * Get the location of the latest trace archive produced by a rotation.
250 *
251 * The caller must hold the session lock.
252 */
253struct lttng_trace_archive_location *session_get_trace_archive_location(
3e3665b8 254 const struct ltt_session *session)
5d65beab 255{
d2956687 256 int ret;
5d65beab 257 struct lttng_trace_archive_location *location = NULL;
d2956687
JG
258 char *chunk_path = NULL;
259
260 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED ||
261 !session->last_archived_chunk_name) {
262 goto end;
263 }
5d65beab 264
5d65beab
JG
265 switch (session_get_consumer_destination_type(session)) {
266 case CONSUMER_DST_LOCAL:
ecd1a12f
MD
267 ret = asprintf(&chunk_path,
268 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
269 session_get_base_path(session),
270 session->last_archived_chunk_name);
271 if (ret == -1) {
272 goto end;
273 }
5d65beab 274 location = lttng_trace_archive_location_local_create(
d2956687 275 chunk_path);
5d65beab
JG
276 break;
277 case CONSUMER_DST_NET:
278 {
279 const char *hostname;
280 uint16_t control_port, data_port;
281
282 hostname = session_get_net_consumer_hostname(session);
283 session_get_net_consumer_ports(session,
284 &control_port,
285 &data_port);
286 location = lttng_trace_archive_location_relay_create(
287 hostname,
288 LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
ecd1a12f 289 control_port, data_port, session->last_chunk_path);
5d65beab
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290 break;
291 }
292 default:
293 abort();
294 }
295end:
d2956687 296 free(chunk_path);
5d65beab
JG
297 return location;
298}
299
23324029
JD
300/*
301 * Allocate the ltt_sessions_ht_by_id HT.
9c6518bc
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302 *
303 * The session list lock must be held.
23324029
JD
304 */
305int ltt_sessions_ht_alloc(void)
306{
307 int ret = 0;
308
309 DBG("Allocating ltt_sessions_ht_by_id");
310 ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
311 if (!ltt_sessions_ht_by_id) {
312 ret = -1;
313 ERR("Failed to allocate ltt_sessions_ht_by_id");
314 goto end;
315 }
316end:
317 return ret;
318}
319
320/*
321 * Destroy the ltt_sessions_ht_by_id HT.
9c6518bc
JG
322 *
323 * The session list lock must be held.
23324029 324 */
accdc9bf 325static void ltt_sessions_ht_destroy(void)
23324029
JD
326{
327 if (!ltt_sessions_ht_by_id) {
328 return;
329 }
330 ht_cleanup_push(ltt_sessions_ht_by_id);
331 ltt_sessions_ht_by_id = NULL;
332}
333
334/*
335 * Add a ltt_session to the ltt_sessions_ht_by_id.
336 * If unallocated, the ltt_sessions_ht_by_id HT is allocated.
337 * The session list lock must be held.
338 */
339static void add_session_ht(struct ltt_session *ls)
340{
341 int ret;
342
343 assert(ls);
344
345 if (!ltt_sessions_ht_by_id) {
346 ret = ltt_sessions_ht_alloc();
347 if (ret) {
348 ERR("Error allocating the sessions HT");
349 goto end;
350 }
351 }
352 lttng_ht_node_init_u64(&ls->node, ls->id);
353 lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node);
354
355end:
356 return;
357}
358
359/*
360 * Test if ltt_sessions_ht_by_id is empty.
361 * Return 1 if empty, 0 if not empty.
362 * The session list lock must be held.
363 */
def88971 364static int ltt_sessions_ht_empty(void)
23324029
JD
365{
366 int ret;
367
368 if (!ltt_sessions_ht_by_id) {
369 ret = 1;
370 goto end;
371 }
372
373 ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1;
374end:
375 return ret;
376}
377
378/*
379 * Remove a ltt_session from the ltt_sessions_ht_by_id.
380 * If empty, the ltt_sessions_ht_by_id HT is freed.
381 * The session list lock must be held.
382 */
383static void del_session_ht(struct ltt_session *ls)
384{
385 struct lttng_ht_iter iter;
386 int ret;
387
388 assert(ls);
389 assert(ltt_sessions_ht_by_id);
390
391 iter.iter.node = &ls->node.node;
392 ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter);
393 assert(!ret);
394
395 if (ltt_sessions_ht_empty()) {
396 DBG("Empty ltt_sessions_ht_by_id, destroying it");
397 ltt_sessions_ht_destroy();
398 }
399}
400
b5541356 401/*
6c9cc2ab 402 * Acquire session lock
b5541356 403 */
54d01ffb 404void session_lock(struct ltt_session *session)
b5541356 405{
0525e9ae
DG
406 assert(session);
407
6c9cc2ab
DG
408 pthread_mutex_lock(&session->lock);
409}
b5541356 410
6c9cc2ab
DG
411/*
412 * Release session lock
413 */
54d01ffb 414void session_unlock(struct ltt_session *session)
6c9cc2ab 415{
0525e9ae
DG
416 assert(session);
417
6c9cc2ab 418 pthread_mutex_unlock(&session->lock);
b5541356
DG
419}
420
82b69413
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421static
422int _session_set_trace_chunk_no_lock_check(struct ltt_session *session,
d2956687
JG
423 struct lttng_trace_chunk *new_trace_chunk,
424 struct lttng_trace_chunk **_current_trace_chunk)
82b69413
JG
425{
426 int ret;
427 unsigned int i, refs_to_acquire = 0, refs_acquired = 0, refs_to_release = 0;
82b69413
JG
428 struct cds_lfht_iter iter;
429 struct consumer_socket *socket;
d2956687
JG
430 struct lttng_trace_chunk *current_trace_chunk;
431 uint64_t chunk_id;
432 enum lttng_trace_chunk_status chunk_status;
82b69413 433
d2956687 434 rcu_read_lock();
82b69413 435 /*
d2956687
JG
436 * Ownership of current trace chunk is transferred to
437 * `current_trace_chunk`.
82b69413 438 */
d2956687
JG
439 current_trace_chunk = session->current_trace_chunk;
440 session->current_trace_chunk = NULL;
82b69413 441 if (session->ust_session) {
d2956687
JG
442 lttng_trace_chunk_put(
443 session->ust_session->current_trace_chunk);
444 session->ust_session->current_trace_chunk = NULL;
82b69413
JG
445 }
446 if (session->kernel_session) {
d2956687
JG
447 lttng_trace_chunk_put(
448 session->kernel_session->current_trace_chunk);
449 session->kernel_session->current_trace_chunk = NULL;
82b69413 450 }
d2956687
JG
451 if (!new_trace_chunk) {
452 ret = 0;
453 goto end;
82b69413 454 }
d2956687
JG
455 chunk_status = lttng_trace_chunk_get_id(new_trace_chunk, &chunk_id);
456 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
82b69413 457
d2956687
JG
458 refs_to_acquire = 1;
459 refs_to_acquire += !!session->ust_session;
460 refs_to_acquire += !!session->kernel_session;
461
462 for (refs_acquired = 0; refs_acquired < refs_to_acquire;
463 refs_acquired++) {
464 if (!lttng_trace_chunk_get(new_trace_chunk)) {
465 ERR("Failed to acquire reference to new trace chunk of session \"%s\"",
466 session->name);
467 goto error;
82b69413
JG
468 }
469 }
470
d2956687 471 if (session->ust_session) {
e5add6d0
JG
472 const uint64_t relayd_id =
473 session->ust_session->consumer->net_seq_index;
474 const bool is_local_trace =
475 session->ust_session->consumer->type ==
476 CONSUMER_DST_LOCAL;
477
d2956687
JG
478 session->ust_session->current_trace_chunk = new_trace_chunk;
479 if (is_local_trace) {
480 enum lttng_error_code ret_error_code;
82b69413 481
d2956687
JG
482 ret_error_code = ust_app_create_channel_subdirectories(
483 session->ust_session);
484 if (ret_error_code != LTTNG_OK) {
82b69413
JG
485 goto error;
486 }
d2956687
JG
487 }
488 cds_lfht_for_each_entry(
489 session->ust_session->consumer->socks->ht,
490 &iter, socket, node.node) {
491 pthread_mutex_lock(socket->lock);
492 ret = consumer_create_trace_chunk(socket,
493 relayd_id,
494 session->id, new_trace_chunk);
495 pthread_mutex_unlock(socket->lock);
496 if (ret) {
497 goto error;
498 }
499 }
500 }
82b69413 501 if (session->kernel_session) {
e5add6d0
JG
502 const uint64_t relayd_id =
503 session->kernel_session->consumer->net_seq_index;
504 const bool is_local_trace =
505 session->kernel_session->consumer->type ==
506 CONSUMER_DST_LOCAL;
507
d2956687
JG
508 session->kernel_session->current_trace_chunk = new_trace_chunk;
509 if (is_local_trace) {
510 enum lttng_error_code ret_error_code;
511
512 ret_error_code = kernel_create_channel_subdirectories(
513 session->kernel_session);
514 if (ret_error_code != LTTNG_OK) {
d2956687
JG
515 goto error;
516 }
517 }
518 cds_lfht_for_each_entry(
519 session->kernel_session->consumer->socks->ht,
520 &iter, socket, node.node) {
521 pthread_mutex_lock(socket->lock);
522 ret = consumer_create_trace_chunk(socket,
523 relayd_id,
524 session->id, new_trace_chunk);
525 pthread_mutex_unlock(socket->lock);
526 if (ret) {
527 goto error;
528 }
529 }
530 }
82b69413
JG
531
532 /*
533 * Update local current trace chunk state last, only if all remote
d2956687 534 * creations succeeded.
82b69413
JG
535 */
536 session->current_trace_chunk = new_trace_chunk;
d2956687
JG
537 LTTNG_OPTIONAL_SET(&session->most_recent_chunk_id, chunk_id);
538end:
539 if (_current_trace_chunk) {
540 *_current_trace_chunk = current_trace_chunk;
541 current_trace_chunk = NULL;
542 }
543end_no_move:
544 rcu_read_unlock();
545 lttng_trace_chunk_put(current_trace_chunk);
546 return ret;
547error:
82b69413 548 if (session->ust_session) {
d2956687 549 session->ust_session->current_trace_chunk = NULL;
82b69413
JG
550 }
551 if (session->kernel_session) {
d2956687 552 session->kernel_session->current_trace_chunk = NULL;
82b69413 553 }
d2956687 554 /*
82b69413
JG
555 * Release references taken in the case where all references could not
556 * be acquired.
557 */
558 refs_to_release = refs_to_acquire - refs_acquired;
559 for (i = 0; i < refs_to_release; i++) {
560 lttng_trace_chunk_put(new_trace_chunk);
561 }
d2956687
JG
562 ret = -1;
563 goto end_no_move;
82b69413
JG
564}
565
d2956687 566struct lttng_trace_chunk *session_create_new_trace_chunk(
348a81dc
JG
567 const struct ltt_session *session,
568 const struct consumer_output *consumer_output_override,
82b69413
JG
569 const char *session_base_path_override,
570 const char *chunk_name_override)
571{
572 int ret;
82b69413
JG
573 struct lttng_trace_chunk *trace_chunk = NULL;
574 enum lttng_trace_chunk_status chunk_status;
d2956687 575 const time_t chunk_creation_ts = time(NULL);
348a81dc
JG
576 bool is_local_trace;
577 const char *base_path;
82b69413
JG
578 struct lttng_directory_handle session_output_directory;
579 const struct lttng_credentials session_credentials = {
580 .uid = session->uid,
581 .gid = session->gid,
582 };
583 uint64_t next_chunk_id;
348a81dc
JG
584 const struct consumer_output *output;
585
586 if (consumer_output_override) {
587 output = consumer_output_override;
588 } else {
589 assert(session->ust_session || session->kernel_session);
590 output = session->ust_session ?
591 session->ust_session->consumer :
592 session->kernel_session->consumer;
593 }
594
595 is_local_trace = output->type == CONSUMER_DST_LOCAL;
596 base_path = session_base_path_override ? :
597 consumer_output_get_base_path(output);
82b69413 598
d2956687
JG
599 if (chunk_creation_ts == (time_t) -1) {
600 PERROR("Failed to sample time while creation session \"%s\" trace chunk",
82b69413 601 session->name);
82b69413
JG
602 goto error;
603 }
82b69413 604
d2956687
JG
605 next_chunk_id = session->most_recent_chunk_id.is_set ?
606 session->most_recent_chunk_id.value + 1 : 0;
82b69413 607
d2956687
JG
608 trace_chunk = lttng_trace_chunk_create(next_chunk_id,
609 chunk_creation_ts);
82b69413 610 if (!trace_chunk) {
82b69413
JG
611 goto error;
612 }
613
614 if (chunk_name_override) {
615 chunk_status = lttng_trace_chunk_override_name(trace_chunk,
616 chunk_name_override);
d2956687 617 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
82b69413
JG
618 goto error;
619 }
620 }
621
622 if (!is_local_trace) {
623 /*
624 * No need to set crendentials and output directory
625 * for remote trace chunks.
626 */
d2956687 627 goto end;
82b69413
JG
628 }
629
630 chunk_status = lttng_trace_chunk_set_credentials(trace_chunk,
631 &session_credentials);
632 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
82b69413
JG
633 goto error;
634 }
635
d2956687
JG
636 DBG("Creating base output directory of session \"%s\" at %s",
637 session->name, base_path);
82b69413
JG
638 ret = utils_mkdir_recursive(base_path, S_IRWXU | S_IRWXG,
639 session->uid, session->gid);
640 if (ret) {
82b69413
JG
641 goto error;
642 }
643 ret = lttng_directory_handle_init(&session_output_directory,
644 base_path);
645 if (ret) {
82b69413
JG
646 goto error;
647 }
648 chunk_status = lttng_trace_chunk_set_as_owner(trace_chunk,
649 &session_output_directory);
650 lttng_directory_handle_fini(&session_output_directory);
651 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
82b69413
JG
652 goto error;
653 }
d2956687
JG
654end:
655 return trace_chunk;
82b69413
JG
656error:
657 lttng_trace_chunk_put(trace_chunk);
d2956687
JG
658 trace_chunk = NULL;
659 goto end;
660}
661
662int session_close_trace_chunk(const struct ltt_session *session,
bbc4768c 663 struct lttng_trace_chunk *trace_chunk,
ecd1a12f
MD
664 const enum lttng_trace_chunk_command_type *close_command,
665 char *closed_trace_chunk_path)
d2956687
JG
666{
667 int ret = 0;
668 bool error_occurred = false;
669 struct cds_lfht_iter iter;
670 struct consumer_socket *socket;
671 enum lttng_trace_chunk_status chunk_status;
672 const time_t chunk_close_timestamp = time(NULL);
673
bbc4768c
JG
674 if (close_command) {
675 chunk_status = lttng_trace_chunk_set_close_command(
676 trace_chunk, *close_command);
677 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
678 ret = -1;
679 goto end;
680 }
681 }
682
d2956687
JG
683 if (chunk_close_timestamp == (time_t) -1) {
684 ERR("Failed to sample the close timestamp of the current trace chunk of session \"%s\"",
685 session->name);
686 ret = -1;
687 goto end;
688 }
689 chunk_status = lttng_trace_chunk_set_close_timestamp(trace_chunk,
690 chunk_close_timestamp);
691 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
692 ERR("Failed to set the close timestamp of the current trace chunk of session \"%s\"",
693 session->name);
694 ret = -1;
695 goto end;
696 }
697
698 if (session->ust_session) {
0a184d4e
JG
699 const uint64_t relayd_id =
700 session->ust_session->consumer->net_seq_index;
701
d2956687
JG
702 cds_lfht_for_each_entry(
703 session->ust_session->consumer->socks->ht,
704 &iter, socket, node.node) {
705 pthread_mutex_lock(socket->lock);
706 ret = consumer_close_trace_chunk(socket,
0a184d4e 707 relayd_id,
d2956687 708 session->id,
ecd1a12f 709 trace_chunk, closed_trace_chunk_path);
d2956687
JG
710 pthread_mutex_unlock(socket->lock);
711 if (ret) {
712 ERR("Failed to close trace chunk on user space consumer");
713 error_occurred = true;
714 }
715 }
716 }
717 if (session->kernel_session) {
0a184d4e
JG
718 const uint64_t relayd_id =
719 session->kernel_session->consumer->net_seq_index;
720
d2956687
JG
721 cds_lfht_for_each_entry(
722 session->kernel_session->consumer->socks->ht,
723 &iter, socket, node.node) {
724 pthread_mutex_lock(socket->lock);
725 ret = consumer_close_trace_chunk(socket,
0a184d4e 726 relayd_id,
d2956687 727 session->id,
ecd1a12f 728 trace_chunk, closed_trace_chunk_path);
d2956687
JG
729 pthread_mutex_unlock(socket->lock);
730 if (ret) {
731 ERR("Failed to close trace chunk on kernel consumer");
732 error_occurred = true;
733 }
734 }
735 }
736 ret = error_occurred ? -1 : 0;
82b69413 737end:
d2956687 738 return ret;
82b69413
JG
739}
740
741/*
742 * Set a session's current trace chunk.
743 *
744 * Must be called with the session lock held.
745 */
746int session_set_trace_chunk(struct ltt_session *session,
d2956687
JG
747 struct lttng_trace_chunk *new_trace_chunk,
748 struct lttng_trace_chunk **current_trace_chunk)
82b69413
JG
749{
750 ASSERT_LOCKED(session->lock);
d2956687
JG
751 return _session_set_trace_chunk_no_lock_check(session, new_trace_chunk,
752 current_trace_chunk);
82b69413
JG
753}
754
3e3665b8
JG
755static
756void session_notify_destruction(const struct ltt_session *session)
757{
758 size_t i;
759 const size_t count = lttng_dynamic_array_get_count(
760 &session->destroy_notifiers);
761
762 for (i = 0; i < count; i++) {
763 const struct ltt_session_destroy_notifier_element *element =
764 lttng_dynamic_array_get_element(
765 &session->destroy_notifiers, i);
766
767 element->notifier(session, element->user_data);
768 }
769}
770
e32d7f27
JG
771static
772void session_release(struct urcu_ref *ref)
773{
774 int ret;
775 struct ltt_ust_session *usess;
776 struct ltt_kernel_session *ksess;
777 struct ltt_session *session = container_of(ref, typeof(*session), ref);
7fdbed1c 778 const bool session_published = session->published;
e32d7f27 779
d2956687
JG
780 assert(!session->chunk_being_archived);
781
e32d7f27
JG
782 usess = session->ust_session;
783 ksess = session->kernel_session;
3e3665b8 784
d070c424 785 /* Clean kernel session teardown, keeping data for destroy notifier. */
e32d7f27
JG
786 kernel_destroy_session(ksess);
787
d070c424 788 /* UST session teardown, keeping data for destroy notifier. */
e32d7f27
JG
789 if (usess) {
790 /* Close any relayd session */
791 consumer_output_send_destroy_relayd(usess->consumer);
792
793 /* Destroy every UST application related to this session. */
794 ret = ust_app_destroy_trace_all(usess);
795 if (ret) {
796 ERR("Error in ust_app_destroy_trace_all");
797 }
798
d070c424 799 /* Clean up the rest, keeping destroy notifier data. */
e32d7f27
JG
800 trace_ust_destroy_session(usess);
801 }
802
803 /*
804 * Must notify the kernel thread here to update it's poll set in order to
805 * remove the channel(s)' fd just destroyed.
806 */
807 ret = notify_thread_pipe(kernel_poll_pipe[1]);
808 if (ret < 0) {
809 PERROR("write kernel poll pipe");
810 }
811
812 DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
e32d7f27
JG
813
814 consumer_output_put(session->consumer);
815 snapshot_destroy(&session->snapshot);
99d688f2 816
82b69413
JG
817 pthread_mutex_destroy(&session->lock);
818
7fdbed1c 819 if (session_published) {
f4cc5e83
JG
820 ASSERT_LOCKED(ltt_session_list.lock);
821 del_session_list(session);
822 del_session_ht(session);
f4cc5e83 823 }
7fdbed1c 824 session_notify_destruction(session);
d070c424
MD
825
826 kernel_free_session(ksess);
827 session->kernel_session = NULL;
828 if (usess) {
829 trace_ust_free_session(usess);
830 session->ust_session = NULL;
831 }
7fdbed1c 832 lttng_dynamic_array_reset(&session->destroy_notifiers);
d2956687 833 free(session->last_archived_chunk_name);
6fa5fe7c 834 free(session->base_path);
e32d7f27 835 free(session);
7fdbed1c
JG
836 if (session_published) {
837 /*
838 * Broadcast after free-ing to ensure the memory is
839 * reclaimed before the main thread exits.
840 */
841 pthread_cond_broadcast(&ltt_session_list.removal_cond);
842 }
e32d7f27
JG
843}
844
845/*
846 * Acquire a reference to a session.
847 * This function may fail (return false); its return value must be checked.
848 */
849bool session_get(struct ltt_session *session)
850{
851 return urcu_ref_get_unless_zero(&session->ref);
852}
853
854/*
855 * Release a reference to a session.
856 */
857void session_put(struct ltt_session *session)
858{
b178f53e
JG
859 if (!session) {
860 return;
861 }
e32d7f27
JG
862 /*
863 * The session list lock must be held as any session_put()
864 * may cause the removal of the session from the session_list.
865 */
866 ASSERT_LOCKED(ltt_session_list.lock);
867 assert(session->ref.refcount);
868 urcu_ref_put(&session->ref, session_release);
869}
870
871/*
872 * Destroy a session.
873 *
874 * This method does not immediately release/free the session as other
875 * components may still hold a reference to the session. However,
876 * the session should no longer be presented to the user.
877 *
878 * Releases the session list's reference to the session
879 * and marks it as destroyed. Iterations on the session list should be
880 * mindful of the "destroyed" flag.
881 */
882void session_destroy(struct ltt_session *session)
883{
884 assert(!session->destroyed);
885 session->destroyed = true;
886 session_put(session);
887}
888
3e3665b8
JG
889int session_add_destroy_notifier(struct ltt_session *session,
890 ltt_session_destroy_notifier notifier, void *user_data)
891{
892 const struct ltt_session_destroy_notifier_element element = {
893 .notifier = notifier,
894 .user_data = user_data
895 };
896
897 return lttng_dynamic_array_add_element(&session->destroy_notifiers,
898 &element);
899}
900
5b74c7b1 901/*
74babd95 902 * Return a ltt_session structure ptr that matches name. If no session found,
23324029 903 * NULL is returned. This must be called with the session list lock held using
74babd95 904 * session_lock_list and session_unlock_list.
e32d7f27 905 * A reference to the session is implicitly acquired by this function.
5b74c7b1 906 */
58a1a227 907struct ltt_session *session_find_by_name(const char *name)
5b74c7b1 908{
5b74c7b1
DG
909 struct ltt_session *iter;
910
0525e9ae 911 assert(name);
e32d7f27 912 ASSERT_LOCKED(ltt_session_list.lock);
0525e9ae 913
5f822d0a
DG
914 DBG2("Trying to find session by name %s", name);
915
5b74c7b1 916 cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
e32d7f27
JG
917 if (!strncmp(iter->name, name, NAME_MAX) &&
918 !iter->destroyed) {
74babd95 919 goto found;
5b74c7b1
DG
920 }
921 }
922
e32d7f27 923 return NULL;
74babd95 924found:
e32d7f27 925 return session_get(iter) ? iter : NULL;
5b74c7b1
DG
926}
927
23324029
JD
928/*
929 * Return an ltt_session that matches the id. If no session is found,
930 * NULL is returned. This must be called with rcu_read_lock and
931 * session list lock held (to guarantee the lifetime of the session).
932 */
933struct ltt_session *session_find_by_id(uint64_t id)
934{
935 struct lttng_ht_node_u64 *node;
936 struct lttng_ht_iter iter;
937 struct ltt_session *ls;
938
e32d7f27
JG
939 ASSERT_LOCKED(ltt_session_list.lock);
940
d68ec974
JG
941 if (!ltt_sessions_ht_by_id) {
942 goto end;
943 }
944
23324029
JD
945 lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
946 node = lttng_ht_iter_get_node_u64(&iter);
947 if (node == NULL) {
d68ec974 948 goto end;
23324029
JD
949 }
950 ls = caa_container_of(node, struct ltt_session, node);
951
952 DBG3("Session %" PRIu64 " found by id.", id);
e32d7f27 953 return session_get(ls) ? ls : NULL;
23324029 954
d68ec974 955end:
23324029
JD
956 DBG3("Session %" PRIu64 " NOT found by id", id);
957 return NULL;
958}
959
5b74c7b1 960/*
b178f53e
JG
961 * Create a new session and add it to the session list.
962 * Session list lock must be held by the caller.
5b74c7b1 963 */
b178f53e 964enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid,
6fa5fe7c 965 const char *base_path, struct ltt_session **out_session)
5b74c7b1 966{
f3ed775e 967 int ret;
b178f53e
JG
968 enum lttng_error_code ret_code;
969 struct ltt_session *new_session = NULL;
e07ae692 970
b178f53e
JG
971 ASSERT_LOCKED(ltt_session_list.lock);
972 if (name) {
973 struct ltt_session *clashing_session;
974
975 clashing_session = session_find_by_name(name);
976 if (clashing_session) {
977 session_put(clashing_session);
978 ret_code = LTTNG_ERR_EXIST_SESS;
979 goto error;
980 }
981 }
ba7f0ae5 982 new_session = zmalloc(sizeof(struct ltt_session));
b178f53e
JG
983 if (!new_session) {
984 PERROR("Failed to allocate an ltt_session structure");
985 ret_code = LTTNG_ERR_NOMEM;
986 goto error;
5b74c7b1
DG
987 }
988
3e3665b8 989 lttng_dynamic_array_init(&new_session->destroy_notifiers,
93bed9fe
JG
990 sizeof(struct ltt_session_destroy_notifier_element),
991 NULL);
e32d7f27 992 urcu_ref_init(&new_session->ref);
b178f53e 993 pthread_mutex_init(&new_session->lock, NULL);
e32d7f27 994
b178f53e
JG
995 new_session->creation_time = time(NULL);
996 if (new_session->creation_time == (time_t) -1) {
997 PERROR("Failed to sample session creation time");
998 ret_code = LTTNG_ERR_SESSION_FAIL;
f3ed775e
DG
999 goto error;
1000 }
1001
b178f53e
JG
1002 /* Create default consumer output. */
1003 new_session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1004 if (new_session->consumer == NULL) {
1005 ret_code = LTTNG_ERR_NOMEM;
1c1c3634
DG
1006 goto error;
1007 }
1008
b178f53e
JG
1009 if (name) {
1010 ret = lttng_strncpy(new_session->name, name, sizeof(new_session->name));
1011 if (ret) {
1012 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1013 goto error;
1014 }
1015 ret = validate_name(name);
1016 if (ret < 0) {
1017 ret_code = LTTNG_ERR_SESSION_INVALID_CHAR;
1018 goto error;
1019 }
1020 } else {
1021 int i = 0;
1022 bool found_name = false;
1023 char datetime[16];
1024 struct tm *timeinfo;
1025
1026 timeinfo = localtime(&new_session->creation_time);
1027 if (!timeinfo) {
1028 ret_code = LTTNG_ERR_SESSION_FAIL;
1029 goto error;
1030 }
1031 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
1032 for (i = 0; i < INT_MAX; i++) {
1033 struct ltt_session *clashing_session;
1034
1035 if (i == 0) {
1036 ret = snprintf(new_session->name,
1037 sizeof(new_session->name),
1038 "%s-%s",
1039 DEFAULT_SESSION_NAME,
1040 datetime);
1041 } else {
1042 ret = snprintf(new_session->name,
1043 sizeof(new_session->name),
1044 "%s%d-%s",
1045 DEFAULT_SESSION_NAME, i,
1046 datetime);
1047 }
46ef2188 1048 new_session->name_contains_creation_time = true;
b178f53e
JG
1049 if (ret == -1 || ret >= sizeof(new_session->name)) {
1050 /*
1051 * Null-terminate in case the name is used
1052 * in logging statements.
1053 */
1054 new_session->name[sizeof(new_session->name) - 1] = '\0';
1055 ret_code = LTTNG_ERR_SESSION_FAIL;
1056 goto error;
1057 }
1058
1059 clashing_session =
1060 session_find_by_name(new_session->name);
1061 session_put(clashing_session);
1062 if (!clashing_session) {
1063 found_name = true;
1064 break;
1065 }
1066 }
1067 if (found_name) {
1068 DBG("Generated session name \"%s\"", new_session->name);
1069 new_session->has_auto_generated_name = true;
1070 } else {
1071 ERR("Failed to auto-generate a session name");
1072 ret_code = LTTNG_ERR_SESSION_FAIL;
1073 goto error;
1074 }
1075 }
1076
d3e2ba59 1077 ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
73184835
DG
1078 if (ret < 0) {
1079 if (errno == ENAMETOOLONG) {
1080 new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
b178f53e
JG
1081 ERR("Hostname exceeds the maximal permitted length and has been truncated to %s",
1082 new_session->hostname);
73184835 1083 } else {
b178f53e 1084 ret_code = LTTNG_ERR_SESSION_FAIL;
73184835
DG
1085 goto error;
1086 }
d3e2ba59
JD
1087 }
1088
6fa5fe7c
MD
1089 if (base_path) {
1090 new_session->base_path = strdup(base_path);
1091 if (!new_session->base_path) {
1092 ERR("Failed to allocate base path of session \"%s\"",
1093 name);
1094 ret_code = LTTNG_ERR_SESSION_FAIL;
1095 goto error;
1096 }
1097 }
1098
6df2e2c9
MD
1099 new_session->uid = uid;
1100 new_session->gid = gid;
1101
6dc3064a
DG
1102 ret = snapshot_init(&new_session->snapshot);
1103 if (ret < 0) {
b178f53e 1104 ret_code = LTTNG_ERR_NOMEM;
6dc3064a
DG
1105 goto error;
1106 }
1107
4f23c583 1108 new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
92816cc3 1109
b178f53e 1110 /* Add new session to the session list. */
a991f516 1111 new_session->id = add_session_list(new_session);
b178f53e 1112
23324029
JD
1113 /*
1114 * Add the new session to the ltt_sessions_ht_by_id.
1115 * No ownership is taken by the hash table; it is merely
1116 * a wrapper around the session list used for faster access
1117 * by session id.
1118 */
1119 add_session_ht(new_session);
f4cc5e83 1120 new_session->published = true;
b5541356 1121
a4b92340 1122 /*
b178f53e
JG
1123 * Consumer is left to NULL since the create_session_uri command will
1124 * set it up and, if valid, assign it to the session.
a4b92340 1125 */
b178f53e
JG
1126 DBG("Tracing session %s created with ID %" PRIu64 " by uid = %d, gid = %d",
1127 new_session->name, new_session->id, new_session->uid,
1128 new_session->gid);
1129 ret_code = LTTNG_OK;
1130end:
1131 if (new_session) {
1132 (void) session_get(new_session);
1133 *out_session = new_session;
1134 }
1135 return ret_code;
5b74c7b1 1136error:
f4cc5e83 1137 session_put(new_session);
b178f53e
JG
1138 new_session = NULL;
1139 goto end;
5b74c7b1 1140}
2f77fc4b
DG
1141
1142/*
1143 * Check if the UID or GID match the session. Root user has access to all
1144 * sessions.
1145 */
1146int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
1147{
1148 assert(session);
1149
1150 if (uid != session->uid && gid != session->gid && uid != 0) {
1151 return 0;
1152 } else {
1153 return 1;
1154 }
1155}
2961f09e
JG
1156
1157/*
1158 * Set a session's rotation state and reset all associated state.
1159 *
1160 * This function resets the rotation state (check timers, pending
1161 * flags, etc.) and sets the result of the last rotation. The result
1162 * can be queries by a liblttng-ctl client.
1163 *
1164 * Be careful of the result passed to this function. For instance,
1165 * on failure to launch a rotation, a client will expect the rotation
1166 * state to be set to "NO_ROTATION". If an error occured while the
1167 * rotation was "ONGOING", result should be set to "ERROR", which will
1168 * allow a client to report it.
1169 *
1170 * Must be called with the session and session_list locks held.
1171 */
1172int session_reset_rotation_state(struct ltt_session *session,
1173 enum lttng_rotation_state result)
1174{
1175 int ret = 0;
1176
1177 ASSERT_LOCKED(ltt_session_list.lock);
1178 ASSERT_LOCKED(session->lock);
1179
2961f09e
JG
1180 session->rotation_state = result;
1181 if (session->rotation_pending_check_timer_enabled) {
1182 ret = timer_session_rotation_pending_check_stop(session);
1183 }
d2956687
JG
1184 if (session->chunk_being_archived) {
1185 uint64_t chunk_id;
1186 enum lttng_trace_chunk_status chunk_status;
1187
1188 chunk_status = lttng_trace_chunk_get_id(
1189 session->chunk_being_archived,
1190 &chunk_id);
1191 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
1192 LTTNG_OPTIONAL_SET(&session->last_archived_chunk_id,
1193 chunk_id);
1194 lttng_trace_chunk_put(session->chunk_being_archived);
1195 session->chunk_being_archived = NULL;
1196 }
2961f09e
JG
1197 return ret;
1198}
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