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Fix: perform a rotation to a null trace chunk on session destruction
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25 #include <stdio.h>
26
27 #include <common/defaults.h>
28 #include <common/common.h>
29 #include <common/sessiond-comm/sessiond-comm.h>
30 #include <common/relayd/relayd.h>
31 #include <common/utils.h>
32 #include <common/compat/string.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/dynamic-buffer.h>
35 #include <common/buffer-view.h>
36 #include <common/trace-chunk.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/trigger/trigger-internal.h>
39 #include <lttng/condition/condition.h>
40 #include <lttng/action/action.h>
41 #include <lttng/channel.h>
42 #include <lttng/channel-internal.h>
43 #include <lttng/rotate-internal.h>
44 #include <lttng/location-internal.h>
45 #include <lttng/session-internal.h>
46 #include <lttng/userspace-probe-internal.h>
47 #include <lttng/session-descriptor-internal.h>
48 #include <common/string-utils/string-utils.h>
49
50 #include "channel.h"
51 #include "consumer.h"
52 #include "event.h"
53 #include "health-sessiond.h"
54 #include "kernel.h"
55 #include "kernel-consumer.h"
56 #include "lttng-sessiond.h"
57 #include "utils.h"
58 #include "lttng-syscall.h"
59 #include "agent.h"
60 #include "buffer-registry.h"
61 #include "notification-thread.h"
62 #include "notification-thread-commands.h"
63 #include "rotate.h"
64 #include "rotation-thread.h"
65 #include "timer.h"
66 #include "agent-thread.h"
67
68 #include "cmd.h"
69
70 /* Sleep for 100ms between each check for the shm path's deletion. */
71 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
72
73 struct cmd_destroy_session_reply_context {
74 int reply_sock_fd;
75 bool implicit_rotation_on_destroy;
76 };
77
78 static enum lttng_error_code wait_on_path(void *path);
79
80 /*
81 * Command completion handler that is used by the destroy command
82 * when a session that has a non-default shm_path is being destroyed.
83 *
84 * See comment in cmd_destroy_session() for the rationale.
85 */
86 static struct destroy_completion_handler {
87 struct cmd_completion_handler handler;
88 char shm_path[member_sizeof(struct ltt_session, shm_path)];
89 } destroy_completion_handler = {
90 .handler = {
91 .run = wait_on_path,
92 .data = destroy_completion_handler.shm_path
93 },
94 .shm_path = { 0 },
95 };
96
97 static struct cmd_completion_handler *current_completion_handler;
98
99 /*
100 * Used to keep a unique index for each relayd socket created where this value
101 * is associated with streams on the consumer so it can match the right relayd
102 * to send to. It must be accessed with the relayd_net_seq_idx_lock
103 * held.
104 */
105 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
106 static uint64_t relayd_net_seq_idx;
107
108 static int validate_ust_event_name(const char *);
109 static int cmd_enable_event_internal(struct ltt_session *session,
110 struct lttng_domain *domain,
111 char *channel_name, struct lttng_event *event,
112 char *filter_expression,
113 struct lttng_filter_bytecode *filter,
114 struct lttng_event_exclusion *exclusion,
115 int wpipe);
116
117 /*
118 * Create a session path used by list_lttng_sessions for the case that the
119 * session consumer is on the network.
120 */
121 static int build_network_session_path(char *dst, size_t size,
122 struct ltt_session *session)
123 {
124 int ret, kdata_port, udata_port;
125 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
126 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
127
128 assert(session);
129 assert(dst);
130
131 memset(tmp_urls, 0, sizeof(tmp_urls));
132 memset(tmp_uurl, 0, sizeof(tmp_uurl));
133
134 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
135
136 if (session->kernel_session && session->kernel_session->consumer) {
137 kuri = &session->kernel_session->consumer->dst.net.control;
138 kdata_port = session->kernel_session->consumer->dst.net.data.port;
139 }
140
141 if (session->ust_session && session->ust_session->consumer) {
142 uuri = &session->ust_session->consumer->dst.net.control;
143 udata_port = session->ust_session->consumer->dst.net.data.port;
144 }
145
146 if (uuri == NULL && kuri == NULL) {
147 uri = &session->consumer->dst.net.control;
148 kdata_port = session->consumer->dst.net.data.port;
149 } else if (kuri && uuri) {
150 ret = uri_compare(kuri, uuri);
151 if (ret) {
152 /* Not Equal */
153 uri = kuri;
154 /* Build uuri URL string */
155 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
156 if (ret < 0) {
157 goto error;
158 }
159 } else {
160 uri = kuri;
161 }
162 } else if (kuri && uuri == NULL) {
163 uri = kuri;
164 } else if (uuri && kuri == NULL) {
165 uri = uuri;
166 }
167
168 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
169 if (ret < 0) {
170 goto error;
171 }
172
173 /*
174 * Do we have a UST url set. If yes, this means we have both kernel and UST
175 * to print.
176 */
177 if (*tmp_uurl != '\0') {
178 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
179 tmp_urls, kdata_port, tmp_uurl, udata_port);
180 } else {
181 int dport;
182 if (kuri || (!kuri && !uuri)) {
183 dport = kdata_port;
184 } else {
185 /* No kernel URI, use the UST port. */
186 dport = udata_port;
187 }
188 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
189 }
190
191 error:
192 return ret;
193 }
194
195 /*
196 * Get run-time attributes if the session has been started (discarded events,
197 * lost packets).
198 */
199 static int get_kernel_runtime_stats(struct ltt_session *session,
200 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
201 uint64_t *lost_packets)
202 {
203 int ret;
204
205 if (!session->has_been_started) {
206 ret = 0;
207 *discarded_events = 0;
208 *lost_packets = 0;
209 goto end;
210 }
211
212 ret = consumer_get_discarded_events(session->id, kchan->key,
213 session->kernel_session->consumer,
214 discarded_events);
215 if (ret < 0) {
216 goto end;
217 }
218
219 ret = consumer_get_lost_packets(session->id, kchan->key,
220 session->kernel_session->consumer,
221 lost_packets);
222 if (ret < 0) {
223 goto end;
224 }
225
226 end:
227 return ret;
228 }
229
230 /*
231 * Get run-time attributes if the session has been started (discarded events,
232 * lost packets).
233 */
234 static int get_ust_runtime_stats(struct ltt_session *session,
235 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
236 uint64_t *lost_packets)
237 {
238 int ret;
239 struct ltt_ust_session *usess;
240
241 if (!discarded_events || !lost_packets) {
242 ret = -1;
243 goto end;
244 }
245
246 usess = session->ust_session;
247 assert(discarded_events);
248 assert(lost_packets);
249
250 if (!usess || !session->has_been_started) {
251 *discarded_events = 0;
252 *lost_packets = 0;
253 ret = 0;
254 goto end;
255 }
256
257 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
258 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
259 &usess->buffer_reg_uid_list,
260 usess->consumer, uchan->id,
261 uchan->attr.overwrite,
262 discarded_events,
263 lost_packets);
264 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
265 ret = ust_app_pid_get_channel_runtime_stats(usess,
266 uchan, usess->consumer,
267 uchan->attr.overwrite,
268 discarded_events,
269 lost_packets);
270 if (ret < 0) {
271 goto end;
272 }
273 *discarded_events += uchan->per_pid_closed_app_discarded;
274 *lost_packets += uchan->per_pid_closed_app_lost;
275 } else {
276 ERR("Unsupported buffer type");
277 assert(0);
278 ret = -1;
279 goto end;
280 }
281
282 end:
283 return ret;
284 }
285
286 /*
287 * Fill lttng_channel array of all channels.
288 */
289 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
290 struct ltt_session *session, struct lttng_channel *channels,
291 struct lttng_channel_extended *chan_exts)
292 {
293 int i = 0, ret = 0;
294 struct ltt_kernel_channel *kchan;
295
296 DBG("Listing channels for session %s", session->name);
297
298 switch (domain) {
299 case LTTNG_DOMAIN_KERNEL:
300 /* Kernel channels */
301 if (session->kernel_session != NULL) {
302 cds_list_for_each_entry(kchan,
303 &session->kernel_session->channel_list.head, list) {
304 uint64_t discarded_events, lost_packets;
305 struct lttng_channel_extended *extended;
306
307 extended = (struct lttng_channel_extended *)
308 kchan->channel->attr.extended.ptr;
309
310 ret = get_kernel_runtime_stats(session, kchan,
311 &discarded_events, &lost_packets);
312 if (ret < 0) {
313 goto end;
314 }
315 /* Copy lttng_channel struct to array */
316 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
317 channels[i].enabled = kchan->enabled;
318 chan_exts[i].discarded_events =
319 discarded_events;
320 chan_exts[i].lost_packets = lost_packets;
321 chan_exts[i].monitor_timer_interval =
322 extended->monitor_timer_interval;
323 chan_exts[i].blocking_timeout = 0;
324 i++;
325 }
326 }
327 break;
328 case LTTNG_DOMAIN_UST:
329 {
330 struct lttng_ht_iter iter;
331 struct ltt_ust_channel *uchan;
332
333 rcu_read_lock();
334 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
335 &iter.iter, uchan, node.node) {
336 uint64_t discarded_events = 0, lost_packets = 0;
337
338 if (lttng_strncpy(channels[i].name, uchan->name,
339 LTTNG_SYMBOL_NAME_LEN)) {
340 break;
341 }
342 channels[i].attr.overwrite = uchan->attr.overwrite;
343 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
344 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
345 channels[i].attr.switch_timer_interval =
346 uchan->attr.switch_timer_interval;
347 channels[i].attr.read_timer_interval =
348 uchan->attr.read_timer_interval;
349 channels[i].enabled = uchan->enabled;
350 channels[i].attr.tracefile_size = uchan->tracefile_size;
351 channels[i].attr.tracefile_count = uchan->tracefile_count;
352
353 /*
354 * Map enum lttng_ust_output to enum lttng_event_output.
355 */
356 switch (uchan->attr.output) {
357 case LTTNG_UST_MMAP:
358 channels[i].attr.output = LTTNG_EVENT_MMAP;
359 break;
360 default:
361 /*
362 * LTTNG_UST_MMAP is the only supported UST
363 * output mode.
364 */
365 assert(0);
366 break;
367 }
368
369 chan_exts[i].monitor_timer_interval =
370 uchan->monitor_timer_interval;
371 chan_exts[i].blocking_timeout =
372 uchan->attr.u.s.blocking_timeout;
373
374 ret = get_ust_runtime_stats(session, uchan,
375 &discarded_events, &lost_packets);
376 if (ret < 0) {
377 break;
378 }
379 chan_exts[i].discarded_events = discarded_events;
380 chan_exts[i].lost_packets = lost_packets;
381 i++;
382 }
383 rcu_read_unlock();
384 break;
385 }
386 default:
387 break;
388 }
389
390 end:
391 if (ret < 0) {
392 return -LTTNG_ERR_FATAL;
393 } else {
394 return LTTNG_OK;
395 }
396 }
397
398 static int increment_extended_len(const char *filter_expression,
399 struct lttng_event_exclusion *exclusion,
400 const struct lttng_userspace_probe_location *probe_location,
401 size_t *extended_len)
402 {
403 int ret = 0;
404
405 *extended_len += sizeof(struct lttcomm_event_extended_header);
406
407 if (filter_expression) {
408 *extended_len += strlen(filter_expression) + 1;
409 }
410
411 if (exclusion) {
412 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
413 }
414
415 if (probe_location) {
416 ret = lttng_userspace_probe_location_serialize(probe_location,
417 NULL, NULL);
418 if (ret < 0) {
419 goto end;
420 }
421 *extended_len += ret;
422 }
423 ret = 0;
424 end:
425 return ret;
426 }
427
428 static int append_extended_info(const char *filter_expression,
429 struct lttng_event_exclusion *exclusion,
430 struct lttng_userspace_probe_location *probe_location,
431 void **extended_at)
432 {
433 int ret = 0;
434 size_t filter_len = 0;
435 size_t nb_exclusions = 0;
436 size_t userspace_probe_location_len = 0;
437 struct lttng_dynamic_buffer location_buffer;
438 struct lttcomm_event_extended_header extended_header;
439
440 if (filter_expression) {
441 filter_len = strlen(filter_expression) + 1;
442 }
443
444 if (exclusion) {
445 nb_exclusions = exclusion->count;
446 }
447
448 if (probe_location) {
449 lttng_dynamic_buffer_init(&location_buffer);
450 ret = lttng_userspace_probe_location_serialize(probe_location,
451 &location_buffer, NULL);
452 if (ret < 0) {
453 ret = -1;
454 goto end;
455 }
456 userspace_probe_location_len = location_buffer.size;
457 }
458
459 /* Set header fields */
460 extended_header.filter_len = filter_len;
461 extended_header.nb_exclusions = nb_exclusions;
462 extended_header.userspace_probe_location_len = userspace_probe_location_len;
463
464 /* Copy header */
465 memcpy(*extended_at, &extended_header, sizeof(extended_header));
466 *extended_at += sizeof(extended_header);
467
468 /* Copy filter string */
469 if (filter_expression) {
470 memcpy(*extended_at, filter_expression, filter_len);
471 *extended_at += filter_len;
472 }
473
474 /* Copy exclusion names */
475 if (exclusion) {
476 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
477
478 memcpy(*extended_at, &exclusion->names, len);
479 *extended_at += len;
480 }
481
482 if (probe_location) {
483 memcpy(*extended_at, location_buffer.data, location_buffer.size);
484 *extended_at += location_buffer.size;
485 lttng_dynamic_buffer_reset(&location_buffer);
486 }
487 ret = 0;
488 end:
489 return ret;
490 }
491
492 /*
493 * Create a list of agent domain events.
494 *
495 * Return number of events in list on success or else a negative value.
496 */
497 static int list_lttng_agent_events(struct agent *agt,
498 struct lttng_event **events, size_t *total_size)
499 {
500 int i = 0, ret = 0;
501 unsigned int nb_event = 0;
502 struct agent_event *event;
503 struct lttng_event *tmp_events = NULL;
504 struct lttng_ht_iter iter;
505 size_t extended_len = 0;
506 void *extended_at;
507
508 assert(agt);
509 assert(events);
510
511 DBG3("Listing agent events");
512
513 rcu_read_lock();
514 nb_event = lttng_ht_get_count(agt->events);
515 rcu_read_unlock();
516 if (nb_event == 0) {
517 ret = nb_event;
518 *total_size = 0;
519 goto error;
520 }
521
522 /* Compute required extended infos size */
523 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
524
525 /*
526 * This is only valid because the commands which add events are
527 * processed in the same thread as the listing.
528 */
529 rcu_read_lock();
530 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
531 ret = increment_extended_len(event->filter_expression, NULL, NULL,
532 &extended_len);
533 if (ret) {
534 DBG("Error computing the length of extended info message");
535 ret = -LTTNG_ERR_FATAL;
536 goto error;
537 }
538 }
539 rcu_read_unlock();
540
541 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
542 tmp_events = zmalloc(*total_size);
543 if (!tmp_events) {
544 PERROR("zmalloc agent events session");
545 ret = -LTTNG_ERR_FATAL;
546 goto error;
547 }
548
549 extended_at = ((uint8_t *) tmp_events) +
550 nb_event * sizeof(struct lttng_event);
551
552 rcu_read_lock();
553 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
554 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
555 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
556 tmp_events[i].enabled = event->enabled;
557 tmp_events[i].loglevel = event->loglevel_value;
558 tmp_events[i].loglevel_type = event->loglevel_type;
559 i++;
560
561 /* Append extended info */
562 ret = append_extended_info(event->filter_expression, NULL, NULL,
563 &extended_at);
564 if (ret) {
565 DBG("Error appending extended info message");
566 ret = -LTTNG_ERR_FATAL;
567 goto error;
568 }
569 }
570
571 *events = tmp_events;
572 ret = nb_event;
573 assert(nb_event == i);
574
575 end:
576 rcu_read_unlock();
577 return ret;
578 error:
579 free(tmp_events);
580 goto end;
581 }
582
583 /*
584 * Create a list of ust global domain events.
585 */
586 static int list_lttng_ust_global_events(char *channel_name,
587 struct ltt_ust_domain_global *ust_global,
588 struct lttng_event **events, size_t *total_size)
589 {
590 int i = 0, ret = 0;
591 unsigned int nb_event = 0;
592 struct lttng_ht_iter iter;
593 struct lttng_ht_node_str *node;
594 struct ltt_ust_channel *uchan;
595 struct ltt_ust_event *uevent;
596 struct lttng_event *tmp;
597 size_t extended_len = 0;
598 void *extended_at;
599
600 DBG("Listing UST global events for channel %s", channel_name);
601
602 rcu_read_lock();
603
604 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
605 node = lttng_ht_iter_get_node_str(&iter);
606 if (node == NULL) {
607 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
608 goto end;
609 }
610
611 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
612
613 nb_event = lttng_ht_get_count(uchan->events);
614 if (nb_event == 0) {
615 ret = nb_event;
616 *total_size = 0;
617 goto end;
618 }
619
620 DBG3("Listing UST global %d events", nb_event);
621
622 /* Compute required extended infos size */
623 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
624 if (uevent->internal) {
625 nb_event--;
626 continue;
627 }
628
629 ret = increment_extended_len(uevent->filter_expression,
630 uevent->exclusion, NULL, &extended_len);
631 if (ret) {
632 DBG("Error computing the length of extended info message");
633 ret = -LTTNG_ERR_FATAL;
634 goto end;
635 }
636 }
637 if (nb_event == 0) {
638 /* All events are internal, skip. */
639 ret = 0;
640 *total_size = 0;
641 goto end;
642 }
643
644 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
645 tmp = zmalloc(*total_size);
646 if (tmp == NULL) {
647 ret = -LTTNG_ERR_FATAL;
648 goto end;
649 }
650
651 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
652
653 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
654 if (uevent->internal) {
655 /* This event should remain hidden from clients */
656 continue;
657 }
658 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
659 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
660 tmp[i].enabled = uevent->enabled;
661
662 switch (uevent->attr.instrumentation) {
663 case LTTNG_UST_TRACEPOINT:
664 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
665 break;
666 case LTTNG_UST_PROBE:
667 tmp[i].type = LTTNG_EVENT_PROBE;
668 break;
669 case LTTNG_UST_FUNCTION:
670 tmp[i].type = LTTNG_EVENT_FUNCTION;
671 break;
672 }
673
674 tmp[i].loglevel = uevent->attr.loglevel;
675 switch (uevent->attr.loglevel_type) {
676 case LTTNG_UST_LOGLEVEL_ALL:
677 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
678 break;
679 case LTTNG_UST_LOGLEVEL_RANGE:
680 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
681 break;
682 case LTTNG_UST_LOGLEVEL_SINGLE:
683 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
684 break;
685 }
686 if (uevent->filter) {
687 tmp[i].filter = 1;
688 }
689 if (uevent->exclusion) {
690 tmp[i].exclusion = 1;
691 }
692 i++;
693
694 /* Append extended info */
695 ret = append_extended_info(uevent->filter_expression,
696 uevent->exclusion, NULL, &extended_at);
697 if (ret) {
698 DBG("Error appending extended info message");
699 ret = -LTTNG_ERR_FATAL;
700 goto end;
701 }
702 }
703
704 ret = nb_event;
705 *events = tmp;
706 end:
707 rcu_read_unlock();
708 return ret;
709 }
710
711 /*
712 * Fill lttng_event array of all kernel events in the channel.
713 */
714 static int list_lttng_kernel_events(char *channel_name,
715 struct ltt_kernel_session *kernel_session,
716 struct lttng_event **events, size_t *total_size)
717 {
718 int i = 0, ret;
719 unsigned int nb_event;
720 struct ltt_kernel_event *event;
721 struct ltt_kernel_channel *kchan;
722 size_t extended_len = 0;
723 void *extended_at;
724
725 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
726 if (kchan == NULL) {
727 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
728 goto error;
729 }
730
731 nb_event = kchan->event_count;
732
733 DBG("Listing events for channel %s", kchan->channel->name);
734
735 if (nb_event == 0) {
736 *total_size = 0;
737 *events = NULL;
738 goto end;
739 }
740
741 /* Compute required extended infos size */
742 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
743 ret = increment_extended_len(event->filter_expression, NULL,
744 event->userspace_probe_location,
745 &extended_len);
746 if (ret) {
747 DBG("Error computing the length of extended info message");
748 ret = -LTTNG_ERR_FATAL;
749 goto error;
750 }
751 }
752
753 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
754 *events = zmalloc(*total_size);
755 if (*events == NULL) {
756 ret = -LTTNG_ERR_FATAL;
757 goto error;
758 }
759
760 extended_at = ((void *) *events) +
761 nb_event * sizeof(struct lttng_event);
762
763 /* Kernel channels */
764 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
765 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
766 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
767 (*events)[i].enabled = event->enabled;
768 (*events)[i].filter =
769 (unsigned char) !!event->filter_expression;
770
771 switch (event->event->instrumentation) {
772 case LTTNG_KERNEL_TRACEPOINT:
773 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
774 break;
775 case LTTNG_KERNEL_KRETPROBE:
776 (*events)[i].type = LTTNG_EVENT_FUNCTION;
777 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
778 sizeof(struct lttng_kernel_kprobe));
779 break;
780 case LTTNG_KERNEL_KPROBE:
781 (*events)[i].type = LTTNG_EVENT_PROBE;
782 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
783 sizeof(struct lttng_kernel_kprobe));
784 break;
785 case LTTNG_KERNEL_UPROBE:
786 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
787 break;
788 case LTTNG_KERNEL_FUNCTION:
789 (*events)[i].type = LTTNG_EVENT_FUNCTION;
790 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
791 sizeof(struct lttng_kernel_function));
792 break;
793 case LTTNG_KERNEL_NOOP:
794 (*events)[i].type = LTTNG_EVENT_NOOP;
795 break;
796 case LTTNG_KERNEL_SYSCALL:
797 (*events)[i].type = LTTNG_EVENT_SYSCALL;
798 break;
799 case LTTNG_KERNEL_ALL:
800 /* fall-through. */
801 default:
802 assert(0);
803 break;
804 }
805 i++;
806
807 /* Append extended info */
808 ret = append_extended_info(event->filter_expression, NULL,
809 event->userspace_probe_location, &extended_at);
810 if (ret) {
811 DBG("Error appending extended info message");
812 ret = -LTTNG_ERR_FATAL;
813 goto error;
814 }
815 }
816
817 end:
818 return nb_event;
819
820 error:
821 /* Negate the error code to differentiate the size from an error */
822 return -ret;
823 }
824
825 /*
826 * Add URI so the consumer output object. Set the correct path depending on the
827 * domain adding the default trace directory.
828 */
829 static enum lttng_error_code add_uri_to_consumer(
830 const struct ltt_session *session,
831 struct consumer_output *consumer,
832 struct lttng_uri *uri, enum lttng_domain_type domain)
833 {
834 int ret;
835 enum lttng_error_code ret_code = LTTNG_OK;
836
837 assert(uri);
838
839 if (consumer == NULL) {
840 DBG("No consumer detected. Don't add URI. Stopping.");
841 ret_code = LTTNG_ERR_NO_CONSUMER;
842 goto error;
843 }
844
845 switch (domain) {
846 case LTTNG_DOMAIN_KERNEL:
847 ret = lttng_strncpy(consumer->domain_subdir,
848 DEFAULT_KERNEL_TRACE_DIR,
849 sizeof(consumer->domain_subdir));
850 break;
851 case LTTNG_DOMAIN_UST:
852 ret = lttng_strncpy(consumer->domain_subdir,
853 DEFAULT_UST_TRACE_DIR,
854 sizeof(consumer->domain_subdir));
855 break;
856 default:
857 /*
858 * This case is possible is we try to add the URI to the global
859 * tracing session consumer object which in this case there is
860 * no subdir.
861 */
862 memset(consumer->domain_subdir, 0,
863 sizeof(consumer->domain_subdir));
864 ret = 0;
865 }
866 if (ret) {
867 ERR("Failed to initialize consumer output domain subdirectory");
868 ret_code = LTTNG_ERR_FATAL;
869 goto error;
870 }
871
872 switch (uri->dtype) {
873 case LTTNG_DST_IPV4:
874 case LTTNG_DST_IPV6:
875 DBG2("Setting network URI to consumer");
876
877 if (consumer->type == CONSUMER_DST_NET) {
878 if ((uri->stype == LTTNG_STREAM_CONTROL &&
879 consumer->dst.net.control_isset) ||
880 (uri->stype == LTTNG_STREAM_DATA &&
881 consumer->dst.net.data_isset)) {
882 ret_code = LTTNG_ERR_URL_EXIST;
883 goto error;
884 }
885 } else {
886 memset(&consumer->dst, 0, sizeof(consumer->dst));
887 }
888
889 /* Set URI into consumer output object */
890 ret = consumer_set_network_uri(session, consumer, uri);
891 if (ret < 0) {
892 ret_code = -ret;
893 goto error;
894 } else if (ret == 1) {
895 /*
896 * URI was the same in the consumer so we do not append the subdir
897 * again so to not duplicate output dir.
898 */
899 ret_code = LTTNG_OK;
900 goto error;
901 }
902 break;
903 case LTTNG_DST_PATH:
904 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
905 ret_code = LTTNG_ERR_INVALID;
906 goto error;
907 }
908 DBG2("Setting trace directory path from URI to %s",
909 uri->dst.path);
910 memset(&consumer->dst, 0, sizeof(consumer->dst));
911
912 ret = lttng_strncpy(consumer->dst.session_root_path,
913 uri->dst.path,
914 sizeof(consumer->dst.session_root_path));
915 consumer->type = CONSUMER_DST_LOCAL;
916 break;
917 }
918
919 ret_code = LTTNG_OK;
920 error:
921 return ret_code;
922 }
923
924 /*
925 * Init tracing by creating trace directory and sending fds kernel consumer.
926 */
927 static int init_kernel_tracing(struct ltt_kernel_session *session)
928 {
929 int ret = 0;
930 struct lttng_ht_iter iter;
931 struct consumer_socket *socket;
932
933 assert(session);
934
935 rcu_read_lock();
936
937 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
938 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
939 socket, node.node) {
940 pthread_mutex_lock(socket->lock);
941 ret = kernel_consumer_send_session(socket, session);
942 pthread_mutex_unlock(socket->lock);
943 if (ret < 0) {
944 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
945 goto error;
946 }
947 }
948 }
949
950 error:
951 rcu_read_unlock();
952 return ret;
953 }
954
955 /*
956 * Create a socket to the relayd using the URI.
957 *
958 * On success, the relayd_sock pointer is set to the created socket.
959 * Else, it remains untouched and an LTTng error code is returned.
960 */
961 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
962 struct lttcomm_relayd_sock **relayd_sock,
963 struct consumer_output *consumer)
964 {
965 int ret;
966 enum lttng_error_code status = LTTNG_OK;
967 struct lttcomm_relayd_sock *rsock;
968
969 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
970 RELAYD_VERSION_COMM_MINOR);
971 if (!rsock) {
972 status = LTTNG_ERR_FATAL;
973 goto error;
974 }
975
976 /*
977 * Connect to relayd so we can proceed with a session creation. This call
978 * can possibly block for an arbitrary amount of time to set the health
979 * state to be in poll execution.
980 */
981 health_poll_entry();
982 ret = relayd_connect(rsock);
983 health_poll_exit();
984 if (ret < 0) {
985 ERR("Unable to reach lttng-relayd");
986 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
987 goto free_sock;
988 }
989
990 /* Create socket for control stream. */
991 if (uri->stype == LTTNG_STREAM_CONTROL) {
992 DBG3("Creating relayd stream socket from URI");
993
994 /* Check relayd version */
995 ret = relayd_version_check(rsock);
996 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
997 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
998 goto close_sock;
999 } else if (ret < 0) {
1000 ERR("Unable to reach lttng-relayd");
1001 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1002 goto close_sock;
1003 }
1004 consumer->relay_major_version = rsock->major;
1005 consumer->relay_minor_version = rsock->minor;
1006 } else if (uri->stype == LTTNG_STREAM_DATA) {
1007 DBG3("Creating relayd data socket from URI");
1008 } else {
1009 /* Command is not valid */
1010 ERR("Relayd invalid stream type: %d", uri->stype);
1011 status = LTTNG_ERR_INVALID;
1012 goto close_sock;
1013 }
1014
1015 *relayd_sock = rsock;
1016
1017 return status;
1018
1019 close_sock:
1020 /* The returned value is not useful since we are on an error path. */
1021 (void) relayd_close(rsock);
1022 free_sock:
1023 free(rsock);
1024 error:
1025 return status;
1026 }
1027
1028 /*
1029 * Connect to the relayd using URI and send the socket to the right consumer.
1030 *
1031 * The consumer socket lock must be held by the caller.
1032 *
1033 * Returns LTTNG_OK on success or an LTTng error code on failure.
1034 */
1035 static enum lttng_error_code send_consumer_relayd_socket(
1036 unsigned int session_id,
1037 struct lttng_uri *relayd_uri,
1038 struct consumer_output *consumer,
1039 struct consumer_socket *consumer_sock,
1040 const char *session_name, const char *hostname,
1041 int session_live_timer,
1042 const uint64_t *current_chunk_id,
1043 time_t session_creation_time)
1044 {
1045 int ret;
1046 struct lttcomm_relayd_sock *rsock = NULL;
1047 enum lttng_error_code status;
1048
1049 /* Connect to relayd and make version check if uri is the control. */
1050 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1051 if (status != LTTNG_OK) {
1052 goto relayd_comm_error;
1053 }
1054 assert(rsock);
1055
1056 /* Set the network sequence index if not set. */
1057 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1058 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1059 /*
1060 * Increment net_seq_idx because we are about to transfer the
1061 * new relayd socket to the consumer.
1062 * Assign unique key so the consumer can match streams.
1063 */
1064 consumer->net_seq_index = ++relayd_net_seq_idx;
1065 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1066 }
1067
1068 /* Send relayd socket to consumer. */
1069 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1070 relayd_uri->stype, session_id,
1071 session_name, hostname, session_live_timer,
1072 current_chunk_id, session_creation_time);
1073 if (ret < 0) {
1074 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1075 goto close_sock;
1076 }
1077
1078 /* Flag that the corresponding socket was sent. */
1079 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1080 consumer_sock->control_sock_sent = 1;
1081 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1082 consumer_sock->data_sock_sent = 1;
1083 }
1084
1085 /*
1086 * Close socket which was dup on the consumer side. The session daemon does
1087 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1088 */
1089
1090 close_sock:
1091 if (status != LTTNG_OK) {
1092 /*
1093 * The consumer output for this session should not be used anymore
1094 * since the relayd connection failed thus making any tracing or/and
1095 * streaming not usable.
1096 */
1097 consumer->enabled = 0;
1098 }
1099 (void) relayd_close(rsock);
1100 free(rsock);
1101
1102 relayd_comm_error:
1103 return status;
1104 }
1105
1106 /*
1107 * Send both relayd sockets to a specific consumer and domain. This is a
1108 * helper function to facilitate sending the information to the consumer for a
1109 * session.
1110 *
1111 * The consumer socket lock must be held by the caller.
1112 *
1113 * Returns LTTNG_OK, or an LTTng error code on failure.
1114 */
1115 static enum lttng_error_code send_consumer_relayd_sockets(
1116 enum lttng_domain_type domain,
1117 unsigned int session_id, struct consumer_output *consumer,
1118 struct consumer_socket *sock, const char *session_name,
1119 const char *hostname, int session_live_timer,
1120 const uint64_t *current_chunk_id, time_t session_creation_time)
1121 {
1122 enum lttng_error_code status = LTTNG_OK;
1123
1124 assert(consumer);
1125 assert(sock);
1126
1127 /* Sending control relayd socket. */
1128 if (!sock->control_sock_sent) {
1129 status = send_consumer_relayd_socket(session_id,
1130 &consumer->dst.net.control, consumer, sock,
1131 session_name, hostname, session_live_timer,
1132 current_chunk_id, session_creation_time);
1133 if (status != LTTNG_OK) {
1134 goto error;
1135 }
1136 }
1137
1138 /* Sending data relayd socket. */
1139 if (!sock->data_sock_sent) {
1140 status = send_consumer_relayd_socket(session_id,
1141 &consumer->dst.net.data, consumer, sock,
1142 session_name, hostname, session_live_timer,
1143 current_chunk_id, session_creation_time);
1144 if (status != LTTNG_OK) {
1145 goto error;
1146 }
1147 }
1148
1149 error:
1150 return status;
1151 }
1152
1153 /*
1154 * Setup relayd connections for a tracing session. First creates the socket to
1155 * the relayd and send them to the right domain consumer. Consumer type MUST be
1156 * network.
1157 */
1158 int cmd_setup_relayd(struct ltt_session *session)
1159 {
1160 int ret = LTTNG_OK;
1161 struct ltt_ust_session *usess;
1162 struct ltt_kernel_session *ksess;
1163 struct consumer_socket *socket;
1164 struct lttng_ht_iter iter;
1165 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1166
1167 assert(session);
1168
1169 usess = session->ust_session;
1170 ksess = session->kernel_session;
1171
1172 DBG("Setting relayd for session %s", session->name);
1173
1174 if (session->current_trace_chunk) {
1175 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1176 session->current_trace_chunk, &current_chunk_id.value);
1177
1178 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1179 current_chunk_id.is_set = true;
1180 } else {
1181 ERR("Failed to get current trace chunk id");
1182 ret = LTTNG_ERR_UNK;
1183 goto error;
1184 }
1185 }
1186
1187 rcu_read_lock();
1188
1189 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1190 && usess->consumer->enabled) {
1191 /* For each consumer socket, send relayd sockets */
1192 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1193 socket, node.node) {
1194 pthread_mutex_lock(socket->lock);
1195 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1196 usess->consumer, socket,
1197 session->name, session->hostname,
1198 session->live_timer,
1199 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1200 session->creation_time);
1201 pthread_mutex_unlock(socket->lock);
1202 if (ret != LTTNG_OK) {
1203 goto error;
1204 }
1205 /* Session is now ready for network streaming. */
1206 session->net_handle = 1;
1207 }
1208 session->consumer->relay_major_version =
1209 usess->consumer->relay_major_version;
1210 session->consumer->relay_minor_version =
1211 usess->consumer->relay_minor_version;
1212 }
1213
1214 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1215 && ksess->consumer->enabled) {
1216 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1217 socket, node.node) {
1218 pthread_mutex_lock(socket->lock);
1219 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1220 ksess->consumer, socket,
1221 session->name, session->hostname,
1222 session->live_timer,
1223 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1224 session->creation_time);
1225 pthread_mutex_unlock(socket->lock);
1226 if (ret != LTTNG_OK) {
1227 goto error;
1228 }
1229 /* Session is now ready for network streaming. */
1230 session->net_handle = 1;
1231 }
1232 session->consumer->relay_major_version =
1233 ksess->consumer->relay_major_version;
1234 session->consumer->relay_minor_version =
1235 ksess->consumer->relay_minor_version;
1236 }
1237
1238 error:
1239 rcu_read_unlock();
1240 return ret;
1241 }
1242
1243 /*
1244 * Start a kernel session by opening all necessary streams.
1245 */
1246 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1247 {
1248 int ret;
1249 struct ltt_kernel_channel *kchan;
1250
1251 /* Open kernel metadata */
1252 if (ksess->metadata == NULL && ksess->output_traces) {
1253 ret = kernel_open_metadata(ksess);
1254 if (ret < 0) {
1255 ret = LTTNG_ERR_KERN_META_FAIL;
1256 goto error;
1257 }
1258 }
1259
1260 /* Open kernel metadata stream */
1261 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1262 ret = kernel_open_metadata_stream(ksess);
1263 if (ret < 0) {
1264 ERR("Kernel create metadata stream failed");
1265 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1266 goto error;
1267 }
1268 }
1269
1270 /* For each channel */
1271 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1272 if (kchan->stream_count == 0) {
1273 ret = kernel_open_channel_stream(kchan);
1274 if (ret < 0) {
1275 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1276 goto error;
1277 }
1278 /* Update the stream global counter */
1279 ksess->stream_count_global += ret;
1280 }
1281 }
1282
1283 /* Setup kernel consumer socket and send fds to it */
1284 ret = init_kernel_tracing(ksess);
1285 if (ret != 0) {
1286 ret = LTTNG_ERR_KERN_START_FAIL;
1287 goto error;
1288 }
1289
1290 /* This start the kernel tracing */
1291 ret = kernel_start_session(ksess);
1292 if (ret < 0) {
1293 ret = LTTNG_ERR_KERN_START_FAIL;
1294 goto error;
1295 }
1296
1297 /* Quiescent wait after starting trace */
1298 kernel_wait_quiescent(wpipe);
1299
1300 ksess->active = 1;
1301
1302 ret = LTTNG_OK;
1303
1304 error:
1305 return ret;
1306 }
1307
1308 /*
1309 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1310 */
1311 int cmd_disable_channel(struct ltt_session *session,
1312 enum lttng_domain_type domain, char *channel_name)
1313 {
1314 int ret;
1315 struct ltt_ust_session *usess;
1316
1317 usess = session->ust_session;
1318
1319 rcu_read_lock();
1320
1321 switch (domain) {
1322 case LTTNG_DOMAIN_KERNEL:
1323 {
1324 ret = channel_kernel_disable(session->kernel_session,
1325 channel_name);
1326 if (ret != LTTNG_OK) {
1327 goto error;
1328 }
1329
1330 kernel_wait_quiescent(kernel_tracer_fd);
1331 break;
1332 }
1333 case LTTNG_DOMAIN_UST:
1334 {
1335 struct ltt_ust_channel *uchan;
1336 struct lttng_ht *chan_ht;
1337
1338 chan_ht = usess->domain_global.channels;
1339
1340 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1341 if (uchan == NULL) {
1342 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1343 goto error;
1344 }
1345
1346 ret = channel_ust_disable(usess, uchan);
1347 if (ret != LTTNG_OK) {
1348 goto error;
1349 }
1350 break;
1351 }
1352 default:
1353 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1354 goto error;
1355 }
1356
1357 ret = LTTNG_OK;
1358
1359 error:
1360 rcu_read_unlock();
1361 return ret;
1362 }
1363
1364 /*
1365 * Command LTTNG_TRACK_PID processed by the client thread.
1366 *
1367 * Called with session lock held.
1368 */
1369 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1370 int pid)
1371 {
1372 int ret;
1373
1374 rcu_read_lock();
1375
1376 switch (domain) {
1377 case LTTNG_DOMAIN_KERNEL:
1378 {
1379 struct ltt_kernel_session *ksess;
1380
1381 ksess = session->kernel_session;
1382
1383 ret = kernel_track_pid(ksess, pid);
1384 if (ret != LTTNG_OK) {
1385 goto error;
1386 }
1387
1388 kernel_wait_quiescent(kernel_tracer_fd);
1389 break;
1390 }
1391 case LTTNG_DOMAIN_UST:
1392 {
1393 struct ltt_ust_session *usess;
1394
1395 usess = session->ust_session;
1396
1397 ret = trace_ust_track_pid(usess, pid);
1398 if (ret != LTTNG_OK) {
1399 goto error;
1400 }
1401 break;
1402 }
1403 default:
1404 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1405 goto error;
1406 }
1407
1408 ret = LTTNG_OK;
1409
1410 error:
1411 rcu_read_unlock();
1412 return ret;
1413 }
1414
1415 /*
1416 * Command LTTNG_UNTRACK_PID processed by the client thread.
1417 *
1418 * Called with session lock held.
1419 */
1420 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1421 int pid)
1422 {
1423 int ret;
1424
1425 rcu_read_lock();
1426
1427 switch (domain) {
1428 case LTTNG_DOMAIN_KERNEL:
1429 {
1430 struct ltt_kernel_session *ksess;
1431
1432 ksess = session->kernel_session;
1433
1434 ret = kernel_untrack_pid(ksess, pid);
1435 if (ret != LTTNG_OK) {
1436 goto error;
1437 }
1438
1439 kernel_wait_quiescent(kernel_tracer_fd);
1440 break;
1441 }
1442 case LTTNG_DOMAIN_UST:
1443 {
1444 struct ltt_ust_session *usess;
1445
1446 usess = session->ust_session;
1447
1448 ret = trace_ust_untrack_pid(usess, pid);
1449 if (ret != LTTNG_OK) {
1450 goto error;
1451 }
1452 break;
1453 }
1454 default:
1455 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1456 goto error;
1457 }
1458
1459 ret = LTTNG_OK;
1460
1461 error:
1462 rcu_read_unlock();
1463 return ret;
1464 }
1465
1466 /*
1467 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1468 *
1469 * The wpipe arguments is used as a notifier for the kernel thread.
1470 */
1471 int cmd_enable_channel(struct ltt_session *session,
1472 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1473 {
1474 int ret;
1475 struct ltt_ust_session *usess = session->ust_session;
1476 struct lttng_ht *chan_ht;
1477 size_t len;
1478
1479 assert(session);
1480 assert(attr);
1481 assert(domain);
1482
1483 len = lttng_strnlen(attr->name, sizeof(attr->name));
1484
1485 /* Validate channel name */
1486 if (attr->name[0] == '.' ||
1487 memchr(attr->name, '/', len) != NULL) {
1488 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1489 goto end;
1490 }
1491
1492 DBG("Enabling channel %s for session %s", attr->name, session->name);
1493
1494 rcu_read_lock();
1495
1496 /*
1497 * Don't try to enable a channel if the session has been started at
1498 * some point in time before. The tracer does not allow it.
1499 */
1500 if (session->has_been_started) {
1501 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1502 goto error;
1503 }
1504
1505 /*
1506 * If the session is a live session, remove the switch timer, the
1507 * live timer does the same thing but sends also synchronisation
1508 * beacons for inactive streams.
1509 */
1510 if (session->live_timer > 0) {
1511 attr->attr.live_timer_interval = session->live_timer;
1512 attr->attr.switch_timer_interval = 0;
1513 }
1514
1515 /* Check for feature support */
1516 switch (domain->type) {
1517 case LTTNG_DOMAIN_KERNEL:
1518 {
1519 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1520 /* Sampling position of buffer is not supported */
1521 WARN("Kernel tracer does not support buffer monitoring. "
1522 "Setting the monitor interval timer to 0 "
1523 "(disabled) for channel '%s' of session '%s'",
1524 attr-> name, session->name);
1525 lttng_channel_set_monitor_timer_interval(attr, 0);
1526 }
1527 break;
1528 }
1529 case LTTNG_DOMAIN_UST:
1530 break;
1531 case LTTNG_DOMAIN_JUL:
1532 case LTTNG_DOMAIN_LOG4J:
1533 case LTTNG_DOMAIN_PYTHON:
1534 if (!agent_tracing_is_enabled()) {
1535 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1536 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1537 goto error;
1538 }
1539 break;
1540 default:
1541 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1542 goto error;
1543 }
1544
1545 switch (domain->type) {
1546 case LTTNG_DOMAIN_KERNEL:
1547 {
1548 struct ltt_kernel_channel *kchan;
1549
1550 kchan = trace_kernel_get_channel_by_name(attr->name,
1551 session->kernel_session);
1552 if (kchan == NULL) {
1553 if (session->snapshot.nb_output > 0 ||
1554 session->snapshot_mode) {
1555 /* Enforce mmap output for snapshot sessions. */
1556 attr->attr.output = LTTNG_EVENT_MMAP;
1557 }
1558 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1559 if (attr->name[0] != '\0') {
1560 session->kernel_session->has_non_default_channel = 1;
1561 }
1562 } else {
1563 ret = channel_kernel_enable(session->kernel_session, kchan);
1564 }
1565
1566 if (ret != LTTNG_OK) {
1567 goto error;
1568 }
1569
1570 kernel_wait_quiescent(kernel_tracer_fd);
1571 break;
1572 }
1573 case LTTNG_DOMAIN_UST:
1574 case LTTNG_DOMAIN_JUL:
1575 case LTTNG_DOMAIN_LOG4J:
1576 case LTTNG_DOMAIN_PYTHON:
1577 {
1578 struct ltt_ust_channel *uchan;
1579
1580 /*
1581 * FIXME
1582 *
1583 * Current agent implementation limitations force us to allow
1584 * only one channel at once in "agent" subdomains. Each
1585 * subdomain has a default channel name which must be strictly
1586 * adhered to.
1587 */
1588 if (domain->type == LTTNG_DOMAIN_JUL) {
1589 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1590 LTTNG_SYMBOL_NAME_LEN)) {
1591 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1592 goto error;
1593 }
1594 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1595 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1596 LTTNG_SYMBOL_NAME_LEN)) {
1597 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1598 goto error;
1599 }
1600 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1601 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1602 LTTNG_SYMBOL_NAME_LEN)) {
1603 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1604 goto error;
1605 }
1606 }
1607
1608 chan_ht = usess->domain_global.channels;
1609
1610 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1611 if (uchan == NULL) {
1612 ret = channel_ust_create(usess, attr, domain->buf_type);
1613 if (attr->name[0] != '\0') {
1614 usess->has_non_default_channel = 1;
1615 }
1616 } else {
1617 ret = channel_ust_enable(usess, uchan);
1618 }
1619 break;
1620 }
1621 default:
1622 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1623 goto error;
1624 }
1625
1626 if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1627 session->has_non_mmap_channel = true;
1628 }
1629 error:
1630 rcu_read_unlock();
1631 end:
1632 return ret;
1633 }
1634
1635 /*
1636 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1637 */
1638 int cmd_disable_event(struct ltt_session *session,
1639 enum lttng_domain_type domain, char *channel_name,
1640 struct lttng_event *event)
1641 {
1642 int ret;
1643 char *event_name;
1644
1645 DBG("Disable event command for event \'%s\'", event->name);
1646
1647 event_name = event->name;
1648
1649 /* Error out on unhandled search criteria */
1650 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1651 || event->pid || event->filter || event->exclusion) {
1652 ret = LTTNG_ERR_UNK;
1653 goto error;
1654 }
1655
1656 rcu_read_lock();
1657
1658 switch (domain) {
1659 case LTTNG_DOMAIN_KERNEL:
1660 {
1661 struct ltt_kernel_channel *kchan;
1662 struct ltt_kernel_session *ksess;
1663
1664 ksess = session->kernel_session;
1665
1666 /*
1667 * If a non-default channel has been created in the
1668 * session, explicitely require that -c chan_name needs
1669 * to be provided.
1670 */
1671 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1672 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1673 goto error_unlock;
1674 }
1675
1676 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1677 if (kchan == NULL) {
1678 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1679 goto error_unlock;
1680 }
1681
1682 switch (event->type) {
1683 case LTTNG_EVENT_ALL:
1684 case LTTNG_EVENT_TRACEPOINT:
1685 case LTTNG_EVENT_SYSCALL:
1686 case LTTNG_EVENT_PROBE:
1687 case LTTNG_EVENT_FUNCTION:
1688 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1689 if (event_name[0] == '\0') {
1690 ret = event_kernel_disable_event(kchan,
1691 NULL, event->type);
1692 } else {
1693 ret = event_kernel_disable_event(kchan,
1694 event_name, event->type);
1695 }
1696 if (ret != LTTNG_OK) {
1697 goto error_unlock;
1698 }
1699 break;
1700 default:
1701 ret = LTTNG_ERR_UNK;
1702 goto error_unlock;
1703 }
1704
1705 kernel_wait_quiescent(kernel_tracer_fd);
1706 break;
1707 }
1708 case LTTNG_DOMAIN_UST:
1709 {
1710 struct ltt_ust_channel *uchan;
1711 struct ltt_ust_session *usess;
1712
1713 usess = session->ust_session;
1714
1715 if (validate_ust_event_name(event_name)) {
1716 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1717 goto error_unlock;
1718 }
1719
1720 /*
1721 * If a non-default channel has been created in the
1722 * session, explicitly require that -c chan_name needs
1723 * to be provided.
1724 */
1725 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1726 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1727 goto error_unlock;
1728 }
1729
1730 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1731 channel_name);
1732 if (uchan == NULL) {
1733 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1734 goto error_unlock;
1735 }
1736
1737 switch (event->type) {
1738 case LTTNG_EVENT_ALL:
1739 /*
1740 * An empty event name means that everything
1741 * should be disabled.
1742 */
1743 if (event->name[0] == '\0') {
1744 ret = event_ust_disable_all_tracepoints(usess, uchan);
1745 } else {
1746 ret = event_ust_disable_tracepoint(usess, uchan,
1747 event_name);
1748 }
1749 if (ret != LTTNG_OK) {
1750 goto error_unlock;
1751 }
1752 break;
1753 default:
1754 ret = LTTNG_ERR_UNK;
1755 goto error_unlock;
1756 }
1757
1758 DBG3("Disable UST event %s in channel %s completed", event_name,
1759 channel_name);
1760 break;
1761 }
1762 case LTTNG_DOMAIN_LOG4J:
1763 case LTTNG_DOMAIN_JUL:
1764 case LTTNG_DOMAIN_PYTHON:
1765 {
1766 struct agent *agt;
1767 struct ltt_ust_session *usess = session->ust_session;
1768
1769 assert(usess);
1770
1771 switch (event->type) {
1772 case LTTNG_EVENT_ALL:
1773 break;
1774 default:
1775 ret = LTTNG_ERR_UNK;
1776 goto error_unlock;
1777 }
1778
1779 agt = trace_ust_find_agent(usess, domain);
1780 if (!agt) {
1781 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1782 goto error_unlock;
1783 }
1784 /*
1785 * An empty event name means that everything
1786 * should be disabled.
1787 */
1788 if (event->name[0] == '\0') {
1789 ret = event_agent_disable_all(usess, agt);
1790 } else {
1791 ret = event_agent_disable(usess, agt, event_name);
1792 }
1793 if (ret != LTTNG_OK) {
1794 goto error_unlock;
1795 }
1796
1797 break;
1798 }
1799 default:
1800 ret = LTTNG_ERR_UND;
1801 goto error_unlock;
1802 }
1803
1804 ret = LTTNG_OK;
1805
1806 error_unlock:
1807 rcu_read_unlock();
1808 error:
1809 return ret;
1810 }
1811
1812 /*
1813 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1814 */
1815 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1816 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1817 {
1818 int ret, chan_kern_created = 0, chan_ust_created = 0;
1819 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1820
1821 /*
1822 * Don't try to add a context if the session has been started at
1823 * some point in time before. The tracer does not allow it and would
1824 * result in a corrupted trace.
1825 */
1826 if (session->has_been_started) {
1827 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1828 goto end;
1829 }
1830
1831 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1832 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1833 app_ctx_name = ctx->u.app_ctx.ctx_name;
1834 }
1835
1836 switch (domain) {
1837 case LTTNG_DOMAIN_KERNEL:
1838 assert(session->kernel_session);
1839
1840 if (session->kernel_session->channel_count == 0) {
1841 /* Create default channel */
1842 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1843 if (ret != LTTNG_OK) {
1844 goto error;
1845 }
1846 chan_kern_created = 1;
1847 }
1848 /* Add kernel context to kernel tracer */
1849 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1850 if (ret != LTTNG_OK) {
1851 goto error;
1852 }
1853 break;
1854 case LTTNG_DOMAIN_JUL:
1855 case LTTNG_DOMAIN_LOG4J:
1856 {
1857 /*
1858 * Validate channel name.
1859 * If no channel name is given and the domain is JUL or LOG4J,
1860 * set it to the appropriate domain-specific channel name. If
1861 * a name is provided but does not match the expexted channel
1862 * name, return an error.
1863 */
1864 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1865 strcmp(channel_name,
1866 DEFAULT_JUL_CHANNEL_NAME)) {
1867 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1868 goto error;
1869 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1870 strcmp(channel_name,
1871 DEFAULT_LOG4J_CHANNEL_NAME)) {
1872 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1873 goto error;
1874 }
1875 /* break is _not_ missing here. */
1876 }
1877 case LTTNG_DOMAIN_UST:
1878 {
1879 struct ltt_ust_session *usess = session->ust_session;
1880 unsigned int chan_count;
1881
1882 assert(usess);
1883
1884 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1885 if (chan_count == 0) {
1886 struct lttng_channel *attr;
1887 /* Create default channel */
1888 attr = channel_new_default_attr(domain, usess->buffer_type);
1889 if (attr == NULL) {
1890 ret = LTTNG_ERR_FATAL;
1891 goto error;
1892 }
1893
1894 ret = channel_ust_create(usess, attr, usess->buffer_type);
1895 if (ret != LTTNG_OK) {
1896 free(attr);
1897 goto error;
1898 }
1899 channel_attr_destroy(attr);
1900 chan_ust_created = 1;
1901 }
1902
1903 ret = context_ust_add(usess, domain, ctx, channel_name);
1904 free(app_ctx_provider_name);
1905 free(app_ctx_name);
1906 app_ctx_name = NULL;
1907 app_ctx_provider_name = NULL;
1908 if (ret != LTTNG_OK) {
1909 goto error;
1910 }
1911 break;
1912 }
1913 default:
1914 ret = LTTNG_ERR_UND;
1915 goto error;
1916 }
1917
1918 ret = LTTNG_OK;
1919 goto end;
1920
1921 error:
1922 if (chan_kern_created) {
1923 struct ltt_kernel_channel *kchan =
1924 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1925 session->kernel_session);
1926 /* Created previously, this should NOT fail. */
1927 assert(kchan);
1928 kernel_destroy_channel(kchan);
1929 }
1930
1931 if (chan_ust_created) {
1932 struct ltt_ust_channel *uchan =
1933 trace_ust_find_channel_by_name(
1934 session->ust_session->domain_global.channels,
1935 DEFAULT_CHANNEL_NAME);
1936 /* Created previously, this should NOT fail. */
1937 assert(uchan);
1938 /* Remove from the channel list of the session. */
1939 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1940 uchan);
1941 trace_ust_destroy_channel(uchan);
1942 }
1943 end:
1944 free(app_ctx_provider_name);
1945 free(app_ctx_name);
1946 return ret;
1947 }
1948
1949 static inline bool name_starts_with(const char *name, const char *prefix)
1950 {
1951 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1952
1953 return !strncmp(name, prefix, max_cmp_len);
1954 }
1955
1956 /* Perform userspace-specific event name validation */
1957 static int validate_ust_event_name(const char *name)
1958 {
1959 int ret = 0;
1960
1961 if (!name) {
1962 ret = -1;
1963 goto end;
1964 }
1965
1966 /*
1967 * Check name against all internal UST event component namespaces used
1968 * by the agents.
1969 */
1970 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1971 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1972 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1973 ret = -1;
1974 }
1975
1976 end:
1977 return ret;
1978 }
1979
1980 /*
1981 * Internal version of cmd_enable_event() with a supplemental
1982 * "internal_event" flag which is used to enable internal events which should
1983 * be hidden from clients. Such events are used in the agent implementation to
1984 * enable the events through which all "agent" events are funeled.
1985 */
1986 static int _cmd_enable_event(struct ltt_session *session,
1987 struct lttng_domain *domain,
1988 char *channel_name, struct lttng_event *event,
1989 char *filter_expression,
1990 struct lttng_filter_bytecode *filter,
1991 struct lttng_event_exclusion *exclusion,
1992 int wpipe, bool internal_event)
1993 {
1994 int ret = 0, channel_created = 0;
1995 struct lttng_channel *attr = NULL;
1996
1997 assert(session);
1998 assert(event);
1999 assert(channel_name);
2000
2001 /* If we have a filter, we must have its filter expression */
2002 assert(!(!!filter_expression ^ !!filter));
2003
2004 /* Normalize event name as a globbing pattern */
2005 strutils_normalize_star_glob_pattern(event->name);
2006
2007 /* Normalize exclusion names as globbing patterns */
2008 if (exclusion) {
2009 size_t i;
2010
2011 for (i = 0; i < exclusion->count; i++) {
2012 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2013
2014 strutils_normalize_star_glob_pattern(name);
2015 }
2016 }
2017
2018 DBG("Enable event command for event \'%s\'", event->name);
2019
2020 rcu_read_lock();
2021
2022 switch (domain->type) {
2023 case LTTNG_DOMAIN_KERNEL:
2024 {
2025 struct ltt_kernel_channel *kchan;
2026
2027 /*
2028 * If a non-default channel has been created in the
2029 * session, explicitely require that -c chan_name needs
2030 * to be provided.
2031 */
2032 if (session->kernel_session->has_non_default_channel
2033 && channel_name[0] == '\0') {
2034 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2035 goto error;
2036 }
2037
2038 kchan = trace_kernel_get_channel_by_name(channel_name,
2039 session->kernel_session);
2040 if (kchan == NULL) {
2041 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2042 LTTNG_BUFFER_GLOBAL);
2043 if (attr == NULL) {
2044 ret = LTTNG_ERR_FATAL;
2045 goto error;
2046 }
2047 if (lttng_strncpy(attr->name, channel_name,
2048 sizeof(attr->name))) {
2049 ret = LTTNG_ERR_INVALID;
2050 goto error;
2051 }
2052
2053 ret = cmd_enable_channel(session, domain, attr, wpipe);
2054 if (ret != LTTNG_OK) {
2055 goto error;
2056 }
2057 channel_created = 1;
2058 }
2059
2060 /* Get the newly created kernel channel pointer */
2061 kchan = trace_kernel_get_channel_by_name(channel_name,
2062 session->kernel_session);
2063 if (kchan == NULL) {
2064 /* This sould not happen... */
2065 ret = LTTNG_ERR_FATAL;
2066 goto error;
2067 }
2068
2069 switch (event->type) {
2070 case LTTNG_EVENT_ALL:
2071 {
2072 char *filter_expression_a = NULL;
2073 struct lttng_filter_bytecode *filter_a = NULL;
2074
2075 /*
2076 * We need to duplicate filter_expression and filter,
2077 * because ownership is passed to first enable
2078 * event.
2079 */
2080 if (filter_expression) {
2081 filter_expression_a = strdup(filter_expression);
2082 if (!filter_expression_a) {
2083 ret = LTTNG_ERR_FATAL;
2084 goto error;
2085 }
2086 }
2087 if (filter) {
2088 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2089 if (!filter_a) {
2090 free(filter_expression_a);
2091 ret = LTTNG_ERR_FATAL;
2092 goto error;
2093 }
2094 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2095 }
2096 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2097 ret = event_kernel_enable_event(kchan, event,
2098 filter_expression, filter);
2099 /* We have passed ownership */
2100 filter_expression = NULL;
2101 filter = NULL;
2102 if (ret != LTTNG_OK) {
2103 if (channel_created) {
2104 /* Let's not leak a useless channel. */
2105 kernel_destroy_channel(kchan);
2106 }
2107 free(filter_expression_a);
2108 free(filter_a);
2109 goto error;
2110 }
2111 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2112 ret = event_kernel_enable_event(kchan, event,
2113 filter_expression_a, filter_a);
2114 /* We have passed ownership */
2115 filter_expression_a = NULL;
2116 filter_a = NULL;
2117 if (ret != LTTNG_OK) {
2118 goto error;
2119 }
2120 break;
2121 }
2122 case LTTNG_EVENT_PROBE:
2123 case LTTNG_EVENT_USERSPACE_PROBE:
2124 case LTTNG_EVENT_FUNCTION:
2125 case LTTNG_EVENT_FUNCTION_ENTRY:
2126 case LTTNG_EVENT_TRACEPOINT:
2127 ret = event_kernel_enable_event(kchan, event,
2128 filter_expression, filter);
2129 /* We have passed ownership */
2130 filter_expression = NULL;
2131 filter = NULL;
2132 if (ret != LTTNG_OK) {
2133 if (channel_created) {
2134 /* Let's not leak a useless channel. */
2135 kernel_destroy_channel(kchan);
2136 }
2137 goto error;
2138 }
2139 break;
2140 case LTTNG_EVENT_SYSCALL:
2141 ret = event_kernel_enable_event(kchan, event,
2142 filter_expression, filter);
2143 /* We have passed ownership */
2144 filter_expression = NULL;
2145 filter = NULL;
2146 if (ret != LTTNG_OK) {
2147 goto error;
2148 }
2149 break;
2150 default:
2151 ret = LTTNG_ERR_UNK;
2152 goto error;
2153 }
2154
2155 kernel_wait_quiescent(kernel_tracer_fd);
2156 break;
2157 }
2158 case LTTNG_DOMAIN_UST:
2159 {
2160 struct ltt_ust_channel *uchan;
2161 struct ltt_ust_session *usess = session->ust_session;
2162
2163 assert(usess);
2164
2165 /*
2166 * If a non-default channel has been created in the
2167 * session, explicitely require that -c chan_name needs
2168 * to be provided.
2169 */
2170 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2171 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2172 goto error;
2173 }
2174
2175 /* Get channel from global UST domain */
2176 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2177 channel_name);
2178 if (uchan == NULL) {
2179 /* Create default channel */
2180 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2181 usess->buffer_type);
2182 if (attr == NULL) {
2183 ret = LTTNG_ERR_FATAL;
2184 goto error;
2185 }
2186 if (lttng_strncpy(attr->name, channel_name,
2187 sizeof(attr->name))) {
2188 ret = LTTNG_ERR_INVALID;
2189 goto error;
2190 }
2191
2192 ret = cmd_enable_channel(session, domain, attr, wpipe);
2193 if (ret != LTTNG_OK) {
2194 goto error;
2195 }
2196
2197 /* Get the newly created channel reference back */
2198 uchan = trace_ust_find_channel_by_name(
2199 usess->domain_global.channels, channel_name);
2200 assert(uchan);
2201 }
2202
2203 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2204 /*
2205 * Don't allow users to add UST events to channels which
2206 * are assigned to a userspace subdomain (JUL, Log4J,
2207 * Python, etc.).
2208 */
2209 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2210 goto error;
2211 }
2212
2213 if (!internal_event) {
2214 /*
2215 * Ensure the event name is not reserved for internal
2216 * use.
2217 */
2218 ret = validate_ust_event_name(event->name);
2219 if (ret) {
2220 WARN("Userspace event name %s failed validation.",
2221 event->name);
2222 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2223 goto error;
2224 }
2225 }
2226
2227 /* At this point, the session and channel exist on the tracer */
2228 ret = event_ust_enable_tracepoint(usess, uchan, event,
2229 filter_expression, filter, exclusion,
2230 internal_event);
2231 /* We have passed ownership */
2232 filter_expression = NULL;
2233 filter = NULL;
2234 exclusion = NULL;
2235 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2236 goto already_enabled;
2237 } else if (ret != LTTNG_OK) {
2238 goto error;
2239 }
2240 break;
2241 }
2242 case LTTNG_DOMAIN_LOG4J:
2243 case LTTNG_DOMAIN_JUL:
2244 case LTTNG_DOMAIN_PYTHON:
2245 {
2246 const char *default_event_name, *default_chan_name;
2247 struct agent *agt;
2248 struct lttng_event uevent;
2249 struct lttng_domain tmp_dom;
2250 struct ltt_ust_session *usess = session->ust_session;
2251
2252 assert(usess);
2253
2254 if (!agent_tracing_is_enabled()) {
2255 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2256 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2257 goto error;
2258 }
2259
2260 agt = trace_ust_find_agent(usess, domain->type);
2261 if (!agt) {
2262 agt = agent_create(domain->type);
2263 if (!agt) {
2264 ret = LTTNG_ERR_NOMEM;
2265 goto error;
2266 }
2267 agent_add(agt, usess->agents);
2268 }
2269
2270 /* Create the default tracepoint. */
2271 memset(&uevent, 0, sizeof(uevent));
2272 uevent.type = LTTNG_EVENT_TRACEPOINT;
2273 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2274 default_event_name = event_get_default_agent_ust_name(
2275 domain->type);
2276 if (!default_event_name) {
2277 ret = LTTNG_ERR_FATAL;
2278 goto error;
2279 }
2280 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2281 uevent.name[sizeof(uevent.name) - 1] = '\0';
2282
2283 /*
2284 * The domain type is changed because we are about to enable the
2285 * default channel and event for the JUL domain that are hardcoded.
2286 * This happens in the UST domain.
2287 */
2288 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2289 tmp_dom.type = LTTNG_DOMAIN_UST;
2290
2291 switch (domain->type) {
2292 case LTTNG_DOMAIN_LOG4J:
2293 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2294 break;
2295 case LTTNG_DOMAIN_JUL:
2296 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2297 break;
2298 case LTTNG_DOMAIN_PYTHON:
2299 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2300 break;
2301 default:
2302 /* The switch/case we are in makes this impossible */
2303 assert(0);
2304 }
2305
2306 {
2307 char *filter_expression_copy = NULL;
2308 struct lttng_filter_bytecode *filter_copy = NULL;
2309
2310 if (filter) {
2311 const size_t filter_size = sizeof(
2312 struct lttng_filter_bytecode)
2313 + filter->len;
2314
2315 filter_copy = zmalloc(filter_size);
2316 if (!filter_copy) {
2317 ret = LTTNG_ERR_NOMEM;
2318 goto error;
2319 }
2320 memcpy(filter_copy, filter, filter_size);
2321
2322 filter_expression_copy =
2323 strdup(filter_expression);
2324 if (!filter_expression) {
2325 ret = LTTNG_ERR_NOMEM;
2326 }
2327
2328 if (!filter_expression_copy || !filter_copy) {
2329 free(filter_expression_copy);
2330 free(filter_copy);
2331 goto error;
2332 }
2333 }
2334
2335 ret = cmd_enable_event_internal(session, &tmp_dom,
2336 (char *) default_chan_name,
2337 &uevent, filter_expression_copy,
2338 filter_copy, NULL, wpipe);
2339 }
2340
2341 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2342 goto already_enabled;
2343 } else if (ret != LTTNG_OK) {
2344 goto error;
2345 }
2346
2347 /* The wild card * means that everything should be enabled. */
2348 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2349 ret = event_agent_enable_all(usess, agt, event, filter,
2350 filter_expression);
2351 } else {
2352 ret = event_agent_enable(usess, agt, event, filter,
2353 filter_expression);
2354 }
2355 filter = NULL;
2356 filter_expression = NULL;
2357 if (ret != LTTNG_OK) {
2358 goto error;
2359 }
2360
2361 break;
2362 }
2363 default:
2364 ret = LTTNG_ERR_UND;
2365 goto error;
2366 }
2367
2368 ret = LTTNG_OK;
2369
2370 already_enabled:
2371 error:
2372 free(filter_expression);
2373 free(filter);
2374 free(exclusion);
2375 channel_attr_destroy(attr);
2376 rcu_read_unlock();
2377 return ret;
2378 }
2379
2380 /*
2381 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2382 * We own filter, exclusion, and filter_expression.
2383 */
2384 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2385 char *channel_name, struct lttng_event *event,
2386 char *filter_expression,
2387 struct lttng_filter_bytecode *filter,
2388 struct lttng_event_exclusion *exclusion,
2389 int wpipe)
2390 {
2391 return _cmd_enable_event(session, domain, channel_name, event,
2392 filter_expression, filter, exclusion, wpipe, false);
2393 }
2394
2395 /*
2396 * Enable an event which is internal to LTTng. An internal should
2397 * never be made visible to clients and are immune to checks such as
2398 * reserved names.
2399 */
2400 static int cmd_enable_event_internal(struct ltt_session *session,
2401 struct lttng_domain *domain,
2402 char *channel_name, struct lttng_event *event,
2403 char *filter_expression,
2404 struct lttng_filter_bytecode *filter,
2405 struct lttng_event_exclusion *exclusion,
2406 int wpipe)
2407 {
2408 return _cmd_enable_event(session, domain, channel_name, event,
2409 filter_expression, filter, exclusion, wpipe, true);
2410 }
2411
2412 /*
2413 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2414 */
2415 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2416 struct lttng_event **events)
2417 {
2418 int ret;
2419 ssize_t nb_events = 0;
2420
2421 switch (domain) {
2422 case LTTNG_DOMAIN_KERNEL:
2423 nb_events = kernel_list_events(kernel_tracer_fd, events);
2424 if (nb_events < 0) {
2425 ret = LTTNG_ERR_KERN_LIST_FAIL;
2426 goto error;
2427 }
2428 break;
2429 case LTTNG_DOMAIN_UST:
2430 nb_events = ust_app_list_events(events);
2431 if (nb_events < 0) {
2432 ret = LTTNG_ERR_UST_LIST_FAIL;
2433 goto error;
2434 }
2435 break;
2436 case LTTNG_DOMAIN_LOG4J:
2437 case LTTNG_DOMAIN_JUL:
2438 case LTTNG_DOMAIN_PYTHON:
2439 nb_events = agent_list_events(events, domain);
2440 if (nb_events < 0) {
2441 ret = LTTNG_ERR_UST_LIST_FAIL;
2442 goto error;
2443 }
2444 break;
2445 default:
2446 ret = LTTNG_ERR_UND;
2447 goto error;
2448 }
2449
2450 return nb_events;
2451
2452 error:
2453 /* Return negative value to differentiate return code */
2454 return -ret;
2455 }
2456
2457 /*
2458 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2459 */
2460 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2461 struct lttng_event_field **fields)
2462 {
2463 int ret;
2464 ssize_t nb_fields = 0;
2465
2466 switch (domain) {
2467 case LTTNG_DOMAIN_UST:
2468 nb_fields = ust_app_list_event_fields(fields);
2469 if (nb_fields < 0) {
2470 ret = LTTNG_ERR_UST_LIST_FAIL;
2471 goto error;
2472 }
2473 break;
2474 case LTTNG_DOMAIN_KERNEL:
2475 default: /* fall-through */
2476 ret = LTTNG_ERR_UND;
2477 goto error;
2478 }
2479
2480 return nb_fields;
2481
2482 error:
2483 /* Return negative value to differentiate return code */
2484 return -ret;
2485 }
2486
2487 ssize_t cmd_list_syscalls(struct lttng_event **events)
2488 {
2489 return syscall_table_list(events);
2490 }
2491
2492 /*
2493 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2494 *
2495 * Called with session lock held.
2496 */
2497 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2498 enum lttng_domain_type domain, int32_t **pids)
2499 {
2500 int ret;
2501 ssize_t nr_pids = 0;
2502
2503 switch (domain) {
2504 case LTTNG_DOMAIN_KERNEL:
2505 {
2506 struct ltt_kernel_session *ksess;
2507
2508 ksess = session->kernel_session;
2509 nr_pids = kernel_list_tracker_pids(ksess, pids);
2510 if (nr_pids < 0) {
2511 ret = LTTNG_ERR_KERN_LIST_FAIL;
2512 goto error;
2513 }
2514 break;
2515 }
2516 case LTTNG_DOMAIN_UST:
2517 {
2518 struct ltt_ust_session *usess;
2519
2520 usess = session->ust_session;
2521 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2522 if (nr_pids < 0) {
2523 ret = LTTNG_ERR_UST_LIST_FAIL;
2524 goto error;
2525 }
2526 break;
2527 }
2528 case LTTNG_DOMAIN_LOG4J:
2529 case LTTNG_DOMAIN_JUL:
2530 case LTTNG_DOMAIN_PYTHON:
2531 default:
2532 ret = LTTNG_ERR_UND;
2533 goto error;
2534 }
2535
2536 return nr_pids;
2537
2538 error:
2539 /* Return negative value to differentiate return code */
2540 return -ret;
2541 }
2542
2543 /*
2544 * Command LTTNG_START_TRACE processed by the client thread.
2545 *
2546 * Called with session mutex held.
2547 */
2548 int cmd_start_trace(struct ltt_session *session)
2549 {
2550 enum lttng_error_code ret;
2551 unsigned long nb_chan = 0;
2552 struct ltt_kernel_session *ksession;
2553 struct ltt_ust_session *usess;
2554
2555 assert(session);
2556
2557 /* Ease our life a bit ;) */
2558 ksession = session->kernel_session;
2559 usess = session->ust_session;
2560
2561 /* Is the session already started? */
2562 if (session->active) {
2563 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2564 goto error;
2565 }
2566
2567 /*
2568 * Starting a session without channel is useless since after that it's not
2569 * possible to enable channel thus inform the client.
2570 */
2571 if (usess && usess->domain_global.channels) {
2572 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2573 }
2574 if (ksession) {
2575 nb_chan += ksession->channel_count;
2576 }
2577 if (!nb_chan) {
2578 ret = LTTNG_ERR_NO_CHANNEL;
2579 goto error;
2580 }
2581
2582 if (session->output_traces && !session->current_trace_chunk &&
2583 session_output_supports_trace_chunks(session)) {
2584 struct lttng_trace_chunk *trace_chunk;
2585
2586 trace_chunk = session_create_new_trace_chunk(
2587 session, NULL, NULL, NULL);
2588 if (!trace_chunk) {
2589 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2590 goto error;
2591 }
2592 assert(!session->current_trace_chunk);
2593 ret = session_set_trace_chunk(session, trace_chunk, NULL);
2594 lttng_trace_chunk_put(trace_chunk);
2595 if (ret) {
2596 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2597 goto error;
2598 }
2599 }
2600
2601 /* Kernel tracing */
2602 if (ksession != NULL) {
2603 DBG("Start kernel tracing session %s", session->name);
2604 ret = start_kernel_session(ksession, kernel_tracer_fd);
2605 if (ret != LTTNG_OK) {
2606 goto error;
2607 }
2608 }
2609
2610 /* Flag session that trace should start automatically */
2611 if (usess) {
2612 int int_ret = ust_app_start_trace_all(usess);
2613
2614 if (int_ret < 0) {
2615 ret = LTTNG_ERR_UST_START_FAIL;
2616 goto error;
2617 }
2618 }
2619
2620 /* Flag this after a successful start. */
2621 session->has_been_started = 1;
2622 session->active = 1;
2623
2624 /*
2625 * Clear the flag that indicates that a rotation was done while the
2626 * session was stopped.
2627 */
2628 session->rotated_after_last_stop = false;
2629
2630 if (session->rotate_timer_period) {
2631 int int_ret = timer_session_rotation_schedule_timer_start(
2632 session, session->rotate_timer_period);
2633
2634 if (int_ret < 0) {
2635 ERR("Failed to enable rotate timer");
2636 ret = LTTNG_ERR_UNK;
2637 goto error;
2638 }
2639 }
2640
2641 ret = LTTNG_OK;
2642
2643 error:
2644 return ret;
2645 }
2646
2647 /*
2648 * Command LTTNG_STOP_TRACE processed by the client thread.
2649 */
2650 int cmd_stop_trace(struct ltt_session *session)
2651 {
2652 int ret;
2653 struct ltt_kernel_channel *kchan;
2654 struct ltt_kernel_session *ksession;
2655 struct ltt_ust_session *usess;
2656 bool error_occurred = false;
2657
2658 assert(session);
2659
2660 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2661 /* Short cut */
2662 ksession = session->kernel_session;
2663 usess = session->ust_session;
2664
2665 /* Session is not active. Skip everythong and inform the client. */
2666 if (!session->active) {
2667 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2668 goto error;
2669 }
2670
2671 /* Kernel tracer */
2672 if (ksession && ksession->active) {
2673 DBG("Stop kernel tracing");
2674
2675 ret = kernel_stop_session(ksession);
2676 if (ret < 0) {
2677 ret = LTTNG_ERR_KERN_STOP_FAIL;
2678 goto error;
2679 }
2680
2681 kernel_wait_quiescent(kernel_tracer_fd);
2682
2683 /* Flush metadata after stopping (if exists) */
2684 if (ksession->metadata_stream_fd >= 0) {
2685 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2686 if (ret < 0) {
2687 ERR("Kernel metadata flush failed");
2688 }
2689 }
2690
2691 /* Flush all buffers after stopping */
2692 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2693 ret = kernel_flush_buffer(kchan);
2694 if (ret < 0) {
2695 ERR("Kernel flush buffer error");
2696 }
2697 }
2698
2699 ksession->active = 0;
2700 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2701 session->id);
2702 }
2703
2704 if (usess && usess->active) {
2705 ret = ust_app_stop_trace_all(usess);
2706 if (ret < 0) {
2707 ret = LTTNG_ERR_UST_STOP_FAIL;
2708 goto error;
2709 }
2710 }
2711
2712 /* Flag inactive after a successful stop. */
2713 session->active = 0;
2714 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2715
2716 error:
2717 return ret;
2718 }
2719
2720 /*
2721 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2722 */
2723 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2724 struct lttng_uri *uris)
2725 {
2726 int ret, i;
2727 struct ltt_kernel_session *ksess = session->kernel_session;
2728 struct ltt_ust_session *usess = session->ust_session;
2729
2730 assert(session);
2731 assert(uris);
2732 assert(nb_uri > 0);
2733
2734 /* Can't set consumer URI if the session is active. */
2735 if (session->active) {
2736 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2737 goto error;
2738 }
2739
2740 /* Set the "global" consumer URIs */
2741 for (i = 0; i < nb_uri; i++) {
2742 ret = add_uri_to_consumer(session,
2743 session->consumer,
2744 &uris[i], LTTNG_DOMAIN_NONE);
2745 if (ret != LTTNG_OK) {
2746 goto error;
2747 }
2748 }
2749
2750 /* Set UST session URIs */
2751 if (session->ust_session) {
2752 for (i = 0; i < nb_uri; i++) {
2753 ret = add_uri_to_consumer(session,
2754 session->ust_session->consumer,
2755 &uris[i], LTTNG_DOMAIN_UST);
2756 if (ret != LTTNG_OK) {
2757 goto error;
2758 }
2759 }
2760 }
2761
2762 /* Set kernel session URIs */
2763 if (session->kernel_session) {
2764 for (i = 0; i < nb_uri; i++) {
2765 ret = add_uri_to_consumer(session,
2766 session->kernel_session->consumer,
2767 &uris[i], LTTNG_DOMAIN_KERNEL);
2768 if (ret != LTTNG_OK) {
2769 goto error;
2770 }
2771 }
2772 }
2773
2774 /*
2775 * Make sure to set the session in output mode after we set URI since a
2776 * session can be created without URL (thus flagged in no output mode).
2777 */
2778 session->output_traces = 1;
2779 if (ksess) {
2780 ksess->output_traces = 1;
2781 }
2782
2783 if (usess) {
2784 usess->output_traces = 1;
2785 }
2786
2787 /* All good! */
2788 ret = LTTNG_OK;
2789
2790 error:
2791 return ret;
2792 }
2793
2794 static
2795 enum lttng_error_code set_session_output_from_descriptor(
2796 struct ltt_session *session,
2797 const struct lttng_session_descriptor *descriptor)
2798 {
2799 int ret;
2800 enum lttng_error_code ret_code = LTTNG_OK;
2801 enum lttng_session_descriptor_type session_type =
2802 lttng_session_descriptor_get_type(descriptor);
2803 enum lttng_session_descriptor_output_type output_type =
2804 lttng_session_descriptor_get_output_type(descriptor);
2805 struct lttng_uri uris[2] = {};
2806 size_t uri_count = 0;
2807
2808 switch (output_type) {
2809 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2810 goto end;
2811 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2812 lttng_session_descriptor_get_local_output_uri(descriptor,
2813 &uris[0]);
2814 uri_count = 1;
2815 break;
2816 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2817 lttng_session_descriptor_get_network_output_uris(descriptor,
2818 &uris[0], &uris[1]);
2819 uri_count = 2;
2820 break;
2821 default:
2822 ret_code = LTTNG_ERR_INVALID;
2823 goto end;
2824 }
2825
2826 switch (session_type) {
2827 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2828 {
2829 struct snapshot_output *new_output = NULL;
2830
2831 new_output = snapshot_output_alloc();
2832 if (!new_output) {
2833 ret_code = LTTNG_ERR_NOMEM;
2834 goto end;
2835 }
2836
2837 ret = snapshot_output_init_with_uri(session,
2838 DEFAULT_SNAPSHOT_MAX_SIZE,
2839 NULL, uris, uri_count, session->consumer,
2840 new_output, &session->snapshot);
2841 if (ret < 0) {
2842 ret_code = (ret == -ENOMEM) ?
2843 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2844 snapshot_output_destroy(new_output);
2845 goto end;
2846 }
2847 snapshot_add_output(&session->snapshot, new_output);
2848 break;
2849 }
2850 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2851 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2852 {
2853 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2854 break;
2855 }
2856 default:
2857 ret_code = LTTNG_ERR_INVALID;
2858 goto end;
2859 }
2860 end:
2861 return ret_code;
2862 }
2863
2864 static
2865 enum lttng_error_code cmd_create_session_from_descriptor(
2866 struct lttng_session_descriptor *descriptor,
2867 const lttng_sock_cred *creds,
2868 const char *home_path)
2869 {
2870 int ret;
2871 enum lttng_error_code ret_code;
2872 const char *session_name;
2873 struct ltt_session *new_session = NULL;
2874 enum lttng_session_descriptor_status descriptor_status;
2875
2876 session_lock_list();
2877 if (home_path) {
2878 if (*home_path != '/') {
2879 ERR("Home path provided by client is not absolute");
2880 ret_code = LTTNG_ERR_INVALID;
2881 goto end;
2882 }
2883 }
2884
2885 descriptor_status = lttng_session_descriptor_get_session_name(
2886 descriptor, &session_name);
2887 switch (descriptor_status) {
2888 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
2889 break;
2890 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
2891 session_name = NULL;
2892 break;
2893 default:
2894 ret_code = LTTNG_ERR_INVALID;
2895 goto end;
2896 }
2897 ret_code = session_create(session_name, creds->uid, creds->gid,
2898 &new_session);
2899 if (ret_code != LTTNG_OK) {
2900 goto end;
2901 }
2902
2903 if (!session_name) {
2904 ret = lttng_session_descriptor_set_session_name(descriptor,
2905 new_session->name);
2906 if (ret) {
2907 ret_code = LTTNG_ERR_SESSION_FAIL;
2908 goto end;
2909 }
2910 }
2911
2912 if (!lttng_session_descriptor_is_output_destination_initialized(
2913 descriptor)) {
2914 /*
2915 * Only include the session's creation time in the output
2916 * destination if the name of the session itself was
2917 * not auto-generated.
2918 */
2919 ret_code = lttng_session_descriptor_set_default_output(
2920 descriptor,
2921 session_name ? &new_session->creation_time : NULL,
2922 home_path);
2923 if (ret_code != LTTNG_OK) {
2924 goto end;
2925 }
2926 } else {
2927 new_session->has_user_specified_directory =
2928 lttng_session_descriptor_has_output_directory(
2929 descriptor);
2930 }
2931
2932 switch (lttng_session_descriptor_get_type(descriptor)) {
2933 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2934 new_session->snapshot_mode = 1;
2935 break;
2936 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2937 new_session->live_timer =
2938 lttng_session_descriptor_live_get_timer_interval(
2939 descriptor);
2940 break;
2941 default:
2942 break;
2943 }
2944
2945 ret_code = set_session_output_from_descriptor(new_session, descriptor);
2946 if (ret_code != LTTNG_OK) {
2947 goto end;
2948 }
2949 new_session->consumer->enabled = 1;
2950 ret_code = LTTNG_OK;
2951 end:
2952 /* Release reference provided by the session_create function. */
2953 session_put(new_session);
2954 if (ret_code != LTTNG_OK && new_session) {
2955 /* Release the global reference on error. */
2956 session_destroy(new_session);
2957 }
2958 session_unlock_list();
2959 return ret_code;
2960 }
2961
2962 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
2963 struct lttng_session_descriptor **return_descriptor)
2964 {
2965 int ret;
2966 size_t payload_size;
2967 struct lttng_dynamic_buffer payload;
2968 struct lttng_buffer_view home_dir_view;
2969 struct lttng_buffer_view session_descriptor_view;
2970 struct lttng_session_descriptor *session_descriptor = NULL;
2971 enum lttng_error_code ret_code;
2972
2973 lttng_dynamic_buffer_init(&payload);
2974 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
2975 LTTNG_PATH_MAX) {
2976 ret_code = LTTNG_ERR_INVALID;
2977 goto error;
2978 }
2979 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
2980 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
2981 ret_code = LTTNG_ERR_INVALID;
2982 goto error;
2983 }
2984
2985 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
2986 cmd_ctx->lsm->u.create_session.session_descriptor_size;
2987 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
2988 if (ret) {
2989 ret_code = LTTNG_ERR_NOMEM;
2990 goto error;
2991 }
2992
2993 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
2994 if (ret <= 0) {
2995 ERR("Reception of session descriptor failed, aborting.");
2996 ret_code = LTTNG_ERR_SESSION_FAIL;
2997 goto error;
2998 }
2999
3000 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3001 &payload,
3002 0,
3003 cmd_ctx->lsm->u.create_session.home_dir_size);
3004 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3005 &payload,
3006 cmd_ctx->lsm->u.create_session.home_dir_size,
3007 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3008
3009 ret = lttng_session_descriptor_create_from_buffer(
3010 &session_descriptor_view, &session_descriptor);
3011 if (ret < 0) {
3012 ERR("Failed to create session descriptor from payload of \"create session\" command");
3013 ret_code = LTTNG_ERR_INVALID;
3014 goto error;
3015 }
3016
3017 /*
3018 * Sets the descriptor's auto-generated properties (name, output) if
3019 * needed.
3020 */
3021 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3022 &cmd_ctx->creds,
3023 home_dir_view.size ? home_dir_view.data : NULL);
3024 if (ret_code != LTTNG_OK) {
3025 goto error;
3026 }
3027
3028 ret_code = LTTNG_OK;
3029 *return_descriptor = session_descriptor;
3030 session_descriptor = NULL;
3031 error:
3032 lttng_dynamic_buffer_reset(&payload);
3033 lttng_session_descriptor_destroy(session_descriptor);
3034 return ret_code;
3035 }
3036
3037 static
3038 void cmd_destroy_session_reply(const struct ltt_session *session,
3039 void *_reply_context)
3040 {
3041 int ret;
3042 ssize_t comm_ret;
3043 const struct cmd_destroy_session_reply_context *reply_context =
3044 _reply_context;
3045 struct lttng_dynamic_buffer payload;
3046 struct lttcomm_session_destroy_command_header cmd_header;
3047 struct lttng_trace_archive_location *location = NULL;
3048 struct lttcomm_lttng_msg llm = {
3049 .cmd_type = LTTNG_DESTROY_SESSION,
3050 .ret_code = LTTNG_OK,
3051 .pid = UINT32_MAX,
3052 .cmd_header_size =
3053 sizeof(struct lttcomm_session_destroy_command_header),
3054 .data_size = 0,
3055 };
3056 size_t payload_size_before_location;
3057
3058 lttng_dynamic_buffer_init(&payload);
3059
3060 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3061 if (ret) {
3062 ERR("Failed to append session destruction message");
3063 goto error;
3064 }
3065
3066 cmd_header.rotation_state =
3067 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3068 session->rotation_state :
3069 LTTNG_ROTATION_STATE_NO_ROTATION);
3070 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3071 sizeof(cmd_header));
3072 if (ret) {
3073 ERR("Failed to append session destruction command header");
3074 goto error;
3075 }
3076
3077 if (!reply_context->implicit_rotation_on_destroy) {
3078 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3079 session->name);
3080 goto send_reply;
3081 }
3082 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3083 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3084 session->name);
3085 goto send_reply;
3086 }
3087
3088 location = session_get_trace_archive_location(session);
3089 if (!location) {
3090 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3091 session->name);
3092 goto error;
3093 }
3094
3095 payload_size_before_location = payload.size;
3096 comm_ret = lttng_trace_archive_location_serialize(location,
3097 &payload);
3098 if (comm_ret < 0) {
3099 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3100 session->name);
3101 goto error;
3102 }
3103 /* Update the message to indicate the location's length. */
3104 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3105 payload.size - payload_size_before_location;
3106 send_reply:
3107 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3108 payload.data, payload.size);
3109 if (comm_ret != (ssize_t) payload.size) {
3110 ERR("Failed to send result of the destruction of session \"%s\" to client",
3111 session->name);
3112 }
3113 error:
3114 ret = close(reply_context->reply_sock_fd);
3115 if (ret) {
3116 PERROR("Failed to close client socket in deferred session destroy reply");
3117 }
3118 lttng_dynamic_buffer_reset(&payload);
3119 free(_reply_context);
3120 }
3121
3122 /*
3123 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3124 *
3125 * Called with session lock held.
3126 */
3127 int cmd_destroy_session(struct ltt_session *session,
3128 struct notification_thread_handle *notification_thread_handle,
3129 int *sock_fd)
3130 {
3131 int ret;
3132 struct cmd_destroy_session_reply_context *reply_context = NULL;
3133
3134 if (sock_fd) {
3135 reply_context = zmalloc(sizeof(*reply_context));
3136 if (!reply_context) {
3137 ret = LTTNG_ERR_NOMEM;
3138 goto end;
3139 }
3140 reply_context->reply_sock_fd = *sock_fd;
3141 }
3142
3143 /* Safety net */
3144 assert(session);
3145
3146 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3147 session->id);
3148 if (session->active) {
3149 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3150 session->name);
3151 ret = cmd_stop_trace(session);
3152 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3153 /* Carry on with the destruction of the session. */
3154 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3155 session->name, lttng_strerror(-ret));
3156 }
3157 }
3158
3159 if (session->rotation_schedule_timer_enabled) {
3160 if (timer_session_rotation_schedule_timer_stop(
3161 session)) {
3162 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3163 session->name);
3164 }
3165 }
3166
3167 if (session->rotate_size) {
3168 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3169 session->rotate_size = 0;
3170 }
3171
3172 if (session->most_recent_chunk_id.is_set &&
3173 session->most_recent_chunk_id.value != 0 &&
3174 session->current_trace_chunk && session->output_traces) {
3175 /*
3176 * Perform a last rotation on destruction if rotations have
3177 * occurred during the session's lifetime.
3178 */
3179 ret = cmd_rotate_session(session, NULL, false);
3180 if (ret != LTTNG_OK) {
3181 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3182 session->name, lttng_strerror(-ret));
3183 }
3184 if (reply_context) {
3185 reply_context->implicit_rotation_on_destroy = true;
3186 }
3187 } else if (session->has_been_started && session->current_trace_chunk &&
3188 session_output_supports_trace_chunks(session)) {
3189 /*
3190 * The user has not triggered a session rotation. However, to
3191 * ensure all data has been consumed, the session is rotated
3192 * to a 'null' trace chunk before it is destroyed.
3193 *
3194 * This is a "quiet" rotation meaning that no notification is
3195 * emitted and no renaming of the current trace chunk takes
3196 * place.
3197 */
3198 ret = cmd_rotate_session(session, NULL, true);
3199 if (ret != LTTNG_OK) {
3200 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3201 session->name, lttng_strerror(-ret));
3202 }
3203 }
3204
3205 if (session->shm_path[0]) {
3206 /*
3207 * When a session is created with an explicit shm_path,
3208 * the consumer daemon will create its shared memory files
3209 * at that location and will *not* unlink them. This is normal
3210 * as the intention of that feature is to make it possible
3211 * to retrieve the content of those files should a crash occur.
3212 *
3213 * To ensure the content of those files can be used, the
3214 * sessiond daemon will replicate the content of the metadata
3215 * cache in a metadata file.
3216 *
3217 * On clean-up, it is expected that the consumer daemon will
3218 * unlink the shared memory files and that the session daemon
3219 * will unlink the metadata file. Then, the session's directory
3220 * in the shm path can be removed.
3221 *
3222 * Unfortunately, a flaw in the design of the sessiond's and
3223 * consumerd's tear down of channels makes it impossible to
3224 * determine when the sessiond _and_ the consumerd have both
3225 * destroyed their representation of a channel. For one, the
3226 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3227 * callbacks in both daemons.
3228 *
3229 * However, it is also impossible for the sessiond to know when
3230 * the consumer daemon is done destroying its channel(s) since
3231 * it occurs as a reaction to the closing of the channel's file
3232 * descriptor. There is no resulting communication initiated
3233 * from the consumerd to the sessiond to confirm that the
3234 * operation is completed (and was successful).
3235 *
3236 * Until this is all fixed, the session daemon checks for the
3237 * removal of the session's shm path which makes it possible
3238 * to safely advertise a session as having been destroyed.
3239 *
3240 * Prior to this fix, it was not possible to reliably save
3241 * a session making use of the --shm-path option, destroy it,
3242 * and load it again. This is because the creation of the
3243 * session would fail upon seeing the session's shm path
3244 * already in existence.
3245 *
3246 * Note that none of the error paths in the check for the
3247 * directory's existence return an error. This is normal
3248 * as there isn't much that can be done. The session will
3249 * be destroyed properly, except that we can't offer the
3250 * guarantee that the same session can be re-created.
3251 */
3252 current_completion_handler = &destroy_completion_handler.handler;
3253 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3254 session->shm_path,
3255 sizeof(destroy_completion_handler.shm_path));
3256 assert(!ret);
3257 }
3258
3259 /*
3260 * The session is destroyed. However, note that the command context
3261 * still holds a reference to the session, thus delaying its destruction
3262 * _at least_ up to the point when that reference is released.
3263 */
3264 session_destroy(session);
3265 if (reply_context) {
3266 ret = session_add_destroy_notifier(session,
3267 cmd_destroy_session_reply,
3268 (void *) reply_context);
3269 if (ret) {
3270 ret = LTTNG_ERR_FATAL;
3271 goto end;
3272 } else {
3273 *sock_fd = -1;
3274 }
3275 }
3276 ret = LTTNG_OK;
3277 end:
3278 return ret;
3279 }
3280
3281 /*
3282 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3283 */
3284 int cmd_register_consumer(struct ltt_session *session,
3285 enum lttng_domain_type domain, const char *sock_path,
3286 struct consumer_data *cdata)
3287 {
3288 int ret, sock;
3289 struct consumer_socket *socket = NULL;
3290
3291 assert(session);
3292 assert(cdata);
3293 assert(sock_path);
3294
3295 switch (domain) {
3296 case LTTNG_DOMAIN_KERNEL:
3297 {
3298 struct ltt_kernel_session *ksess = session->kernel_session;
3299
3300 assert(ksess);
3301
3302 /* Can't register a consumer if there is already one */
3303 if (ksess->consumer_fds_sent != 0) {
3304 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3305 goto error;
3306 }
3307
3308 sock = lttcomm_connect_unix_sock(sock_path);
3309 if (sock < 0) {
3310 ret = LTTNG_ERR_CONNECT_FAIL;
3311 goto error;
3312 }
3313 cdata->cmd_sock = sock;
3314
3315 socket = consumer_allocate_socket(&cdata->cmd_sock);
3316 if (socket == NULL) {
3317 ret = close(sock);
3318 if (ret < 0) {
3319 PERROR("close register consumer");
3320 }
3321 cdata->cmd_sock = -1;
3322 ret = LTTNG_ERR_FATAL;
3323 goto error;
3324 }
3325
3326 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3327 if (socket->lock == NULL) {
3328 PERROR("zmalloc pthread mutex");
3329 ret = LTTNG_ERR_FATAL;
3330 goto error;
3331 }
3332 pthread_mutex_init(socket->lock, NULL);
3333 socket->registered = 1;
3334
3335 rcu_read_lock();
3336 consumer_add_socket(socket, ksess->consumer);
3337 rcu_read_unlock();
3338
3339 pthread_mutex_lock(&cdata->pid_mutex);
3340 cdata->pid = -1;
3341 pthread_mutex_unlock(&cdata->pid_mutex);
3342
3343 break;
3344 }
3345 default:
3346 /* TODO: Userspace tracing */
3347 ret = LTTNG_ERR_UND;
3348 goto error;
3349 }
3350
3351 return LTTNG_OK;
3352
3353 error:
3354 if (socket) {
3355 consumer_destroy_socket(socket);
3356 }
3357 return ret;
3358 }
3359
3360 /*
3361 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3362 */
3363 ssize_t cmd_list_domains(struct ltt_session *session,
3364 struct lttng_domain **domains)
3365 {
3366 int ret, index = 0;
3367 ssize_t nb_dom = 0;
3368 struct agent *agt;
3369 struct lttng_ht_iter iter;
3370
3371 if (session->kernel_session != NULL) {
3372 DBG3("Listing domains found kernel domain");
3373 nb_dom++;
3374 }
3375
3376 if (session->ust_session != NULL) {
3377 DBG3("Listing domains found UST global domain");
3378 nb_dom++;
3379
3380 rcu_read_lock();
3381 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3382 agt, node.node) {
3383 if (agt->being_used) {
3384 nb_dom++;
3385 }
3386 }
3387 rcu_read_unlock();
3388 }
3389
3390 if (!nb_dom) {
3391 goto end;
3392 }
3393
3394 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3395 if (*domains == NULL) {
3396 ret = LTTNG_ERR_FATAL;
3397 goto error;
3398 }
3399
3400 if (session->kernel_session != NULL) {
3401 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3402
3403 /* Kernel session buffer type is always GLOBAL */
3404 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3405
3406 index++;
3407 }
3408
3409 if (session->ust_session != NULL) {
3410 (*domains)[index].type = LTTNG_DOMAIN_UST;
3411 (*domains)[index].buf_type = session->ust_session->buffer_type;
3412 index++;
3413
3414 rcu_read_lock();
3415 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3416 agt, node.node) {
3417 if (agt->being_used) {
3418 (*domains)[index].type = agt->domain;
3419 (*domains)[index].buf_type = session->ust_session->buffer_type;
3420 index++;
3421 }
3422 }
3423 rcu_read_unlock();
3424 }
3425 end:
3426 return nb_dom;
3427
3428 error:
3429 /* Return negative value to differentiate return code */
3430 return -ret;
3431 }
3432
3433
3434 /*
3435 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3436 */
3437 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3438 struct ltt_session *session, struct lttng_channel **channels)
3439 {
3440 ssize_t nb_chan = 0, payload_size = 0, ret;
3441
3442 switch (domain) {
3443 case LTTNG_DOMAIN_KERNEL:
3444 if (session->kernel_session != NULL) {
3445 nb_chan = session->kernel_session->channel_count;
3446 }
3447 DBG3("Number of kernel channels %zd", nb_chan);
3448 if (nb_chan <= 0) {
3449 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3450 goto end;
3451 }
3452 break;
3453 case LTTNG_DOMAIN_UST:
3454 if (session->ust_session != NULL) {
3455 rcu_read_lock();
3456 nb_chan = lttng_ht_get_count(
3457 session->ust_session->domain_global.channels);
3458 rcu_read_unlock();
3459 }
3460 DBG3("Number of UST global channels %zd", nb_chan);
3461 if (nb_chan < 0) {
3462 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3463 goto end;
3464 }
3465 break;
3466 default:
3467 ret = -LTTNG_ERR_UND;
3468 goto end;
3469 }
3470
3471 if (nb_chan > 0) {
3472 const size_t channel_size = sizeof(struct lttng_channel) +
3473 sizeof(struct lttng_channel_extended);
3474 struct lttng_channel_extended *channel_exts;
3475
3476 payload_size = nb_chan * channel_size;
3477 *channels = zmalloc(payload_size);
3478 if (*channels == NULL) {
3479 ret = -LTTNG_ERR_FATAL;
3480 goto end;
3481 }
3482
3483 channel_exts = ((void *) *channels) +
3484 (nb_chan * sizeof(struct lttng_channel));
3485 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3486 if (ret != LTTNG_OK) {
3487 free(*channels);
3488 *channels = NULL;
3489 goto end;
3490 }
3491 } else {
3492 *channels = NULL;
3493 }
3494
3495 ret = payload_size;
3496 end:
3497 return ret;
3498 }
3499
3500 /*
3501 * Command LTTNG_LIST_EVENTS processed by the client thread.
3502 */
3503 ssize_t cmd_list_events(enum lttng_domain_type domain,
3504 struct ltt_session *session, char *channel_name,
3505 struct lttng_event **events, size_t *total_size)
3506 {
3507 int ret = 0;
3508 ssize_t nb_event = 0;
3509
3510 switch (domain) {
3511 case LTTNG_DOMAIN_KERNEL:
3512 if (session->kernel_session != NULL) {
3513 nb_event = list_lttng_kernel_events(channel_name,
3514 session->kernel_session, events,
3515 total_size);
3516 }
3517 break;
3518 case LTTNG_DOMAIN_UST:
3519 {
3520 if (session->ust_session != NULL) {
3521 nb_event = list_lttng_ust_global_events(channel_name,
3522 &session->ust_session->domain_global, events,
3523 total_size);
3524 }
3525 break;
3526 }
3527 case LTTNG_DOMAIN_LOG4J:
3528 case LTTNG_DOMAIN_JUL:
3529 case LTTNG_DOMAIN_PYTHON:
3530 if (session->ust_session) {
3531 struct lttng_ht_iter iter;
3532 struct agent *agt;
3533
3534 rcu_read_lock();
3535 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3536 &iter.iter, agt, node.node) {
3537 if (agt->domain == domain) {
3538 nb_event = list_lttng_agent_events(
3539 agt, events,
3540 total_size);
3541 break;
3542 }
3543 }
3544 rcu_read_unlock();
3545 }
3546 break;
3547 default:
3548 ret = LTTNG_ERR_UND;
3549 goto error;
3550 }
3551
3552 return nb_event;
3553
3554 error:
3555 /* Return negative value to differentiate return code */
3556 return -ret;
3557 }
3558
3559 /*
3560 * Using the session list, filled a lttng_session array to send back to the
3561 * client for session listing.
3562 *
3563 * The session list lock MUST be acquired before calling this function. Use
3564 * session_lock_list() and session_unlock_list().
3565 */
3566 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3567 size_t session_count, uid_t uid, gid_t gid)
3568 {
3569 int ret;
3570 unsigned int i = 0;
3571 struct ltt_session *session;
3572 struct ltt_session_list *list = session_get_list();
3573 struct lttng_session_extended *extended =
3574 (typeof(extended)) (&sessions[session_count]);
3575
3576 DBG("Getting all available session for UID %d GID %d",
3577 uid, gid);
3578 /*
3579 * Iterate over session list and append data after the control struct in
3580 * the buffer.
3581 */
3582 cds_list_for_each_entry(session, &list->head, list) {
3583 if (!session_get(session)) {
3584 continue;
3585 }
3586 /*
3587 * Only list the sessions the user can control.
3588 */
3589 if (!session_access_ok(session, uid, gid) ||
3590 session->destroyed) {
3591 session_put(session);
3592 continue;
3593 }
3594
3595 struct ltt_kernel_session *ksess = session->kernel_session;
3596 struct ltt_ust_session *usess = session->ust_session;
3597
3598 if (session->consumer->type == CONSUMER_DST_NET ||
3599 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3600 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3601 ret = build_network_session_path(sessions[i].path,
3602 sizeof(sessions[i].path), session);
3603 } else {
3604 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3605 session->consumer->dst.session_root_path);
3606 }
3607 if (ret < 0) {
3608 PERROR("snprintf session path");
3609 session_put(session);
3610 continue;
3611 }
3612
3613 strncpy(sessions[i].name, session->name, NAME_MAX);
3614 sessions[i].name[NAME_MAX - 1] = '\0';
3615 sessions[i].enabled = session->active;
3616 sessions[i].snapshot_mode = session->snapshot_mode;
3617 sessions[i].live_timer_interval = session->live_timer;
3618 extended[i].creation_time.value = (uint64_t) session->creation_time;
3619 extended[i].creation_time.is_set = 1;
3620 i++;
3621 session_put(session);
3622 }
3623 }
3624
3625 /*
3626 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3627 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3628 */
3629 int cmd_data_pending(struct ltt_session *session)
3630 {
3631 int ret;
3632 struct ltt_kernel_session *ksess = session->kernel_session;
3633 struct ltt_ust_session *usess = session->ust_session;
3634
3635 assert(session);
3636
3637 DBG("Data pending for session %s", session->name);
3638
3639 /* Session MUST be stopped to ask for data availability. */
3640 if (session->active) {
3641 ret = LTTNG_ERR_SESSION_STARTED;
3642 goto error;
3643 } else {
3644 /*
3645 * If stopped, just make sure we've started before else the above call
3646 * will always send that there is data pending.
3647 *
3648 * The consumer assumes that when the data pending command is received,
3649 * the trace has been started before or else no output data is written
3650 * by the streams which is a condition for data pending. So, this is
3651 * *VERY* important that we don't ask the consumer before a start
3652 * trace.
3653 */
3654 if (!session->has_been_started) {
3655 ret = 0;
3656 goto error;
3657 }
3658 }
3659
3660 /* A rotation is still pending, we have to wait. */
3661 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3662 DBG("Rotate still pending for session %s", session->name);
3663 ret = 1;
3664 goto error;
3665 }
3666
3667 if (ksess && ksess->consumer) {
3668 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3669 if (ret == 1) {
3670 /* Data is still being extracted for the kernel. */
3671 goto error;
3672 }
3673 }
3674
3675 if (usess && usess->consumer) {
3676 ret = consumer_is_data_pending(usess->id, usess->consumer);
3677 if (ret == 1) {
3678 /* Data is still being extracted for the kernel. */
3679 goto error;
3680 }
3681 }
3682
3683 /* Data is ready to be read by a viewer */
3684 ret = 0;
3685
3686 error:
3687 return ret;
3688 }
3689
3690 /*
3691 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3692 *
3693 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3694 */
3695 int cmd_snapshot_add_output(struct ltt_session *session,
3696 struct lttng_snapshot_output *output, uint32_t *id)
3697 {
3698 int ret;
3699 struct snapshot_output *new_output;
3700
3701 assert(session);
3702 assert(output);
3703
3704 DBG("Cmd snapshot add output for session %s", session->name);
3705
3706 /*
3707 * Can't create an output if the session is not set in no-output mode.
3708 */
3709 if (session->output_traces) {
3710 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3711 goto error;
3712 }
3713
3714 if (session->has_non_mmap_channel) {
3715 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3716 goto error;
3717 }
3718
3719 /* Only one output is allowed until we have the "tee" feature. */
3720 if (session->snapshot.nb_output == 1) {
3721 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3722 goto error;
3723 }
3724
3725 new_output = snapshot_output_alloc();
3726 if (!new_output) {
3727 ret = LTTNG_ERR_NOMEM;
3728 goto error;
3729 }
3730
3731 ret = snapshot_output_init(session, output->max_size, output->name,
3732 output->ctrl_url, output->data_url, session->consumer, new_output,
3733 &session->snapshot);
3734 if (ret < 0) {
3735 if (ret == -ENOMEM) {
3736 ret = LTTNG_ERR_NOMEM;
3737 } else {
3738 ret = LTTNG_ERR_INVALID;
3739 }
3740 goto free_error;
3741 }
3742
3743 rcu_read_lock();
3744 snapshot_add_output(&session->snapshot, new_output);
3745 if (id) {
3746 *id = new_output->id;
3747 }
3748 rcu_read_unlock();
3749
3750 return LTTNG_OK;
3751
3752 free_error:
3753 snapshot_output_destroy(new_output);
3754 error:
3755 return ret;
3756 }
3757
3758 /*
3759 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3760 *
3761 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3762 */
3763 int cmd_snapshot_del_output(struct ltt_session *session,
3764 struct lttng_snapshot_output *output)
3765 {
3766 int ret;
3767 struct snapshot_output *sout = NULL;
3768
3769 assert(session);
3770 assert(output);
3771
3772 rcu_read_lock();
3773
3774 /*
3775 * Permission denied to create an output if the session is not
3776 * set in no output mode.
3777 */
3778 if (session->output_traces) {
3779 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3780 goto error;
3781 }
3782
3783 if (output->id) {
3784 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3785 session->name);
3786 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3787 } else if (*output->name != '\0') {
3788 DBG("Cmd snapshot del output name %s for session %s", output->name,
3789 session->name);
3790 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3791 }
3792 if (!sout) {
3793 ret = LTTNG_ERR_INVALID;
3794 goto error;
3795 }
3796
3797 snapshot_delete_output(&session->snapshot, sout);
3798 snapshot_output_destroy(sout);
3799 ret = LTTNG_OK;
3800
3801 error:
3802 rcu_read_unlock();
3803 return ret;
3804 }
3805
3806 /*
3807 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3808 *
3809 * If no output is available, outputs is untouched and 0 is returned.
3810 *
3811 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3812 */
3813 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3814 struct lttng_snapshot_output **outputs)
3815 {
3816 int ret, idx = 0;
3817 struct lttng_snapshot_output *list = NULL;
3818 struct lttng_ht_iter iter;
3819 struct snapshot_output *output;
3820
3821 assert(session);
3822 assert(outputs);
3823
3824 DBG("Cmd snapshot list outputs for session %s", session->name);
3825
3826 /*
3827 * Permission denied to create an output if the session is not
3828 * set in no output mode.
3829 */
3830 if (session->output_traces) {
3831 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3832 goto end;
3833 }
3834
3835 if (session->snapshot.nb_output == 0) {
3836 ret = 0;
3837 goto end;
3838 }
3839
3840 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3841 if (!list) {
3842 ret = -LTTNG_ERR_NOMEM;
3843 goto end;
3844 }
3845
3846 /* Copy list from session to the new list object. */
3847 rcu_read_lock();
3848 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3849 output, node.node) {
3850 assert(output->consumer);
3851 list[idx].id = output->id;
3852 list[idx].max_size = output->max_size;
3853 if (lttng_strncpy(list[idx].name, output->name,
3854 sizeof(list[idx].name))) {
3855 ret = -LTTNG_ERR_INVALID;
3856 goto error;
3857 }
3858 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3859 if (lttng_strncpy(list[idx].ctrl_url,
3860 output->consumer->dst.session_root_path,
3861 sizeof(list[idx].ctrl_url))) {
3862 ret = -LTTNG_ERR_INVALID;
3863 goto error;
3864 }
3865 } else {
3866 /* Control URI. */
3867 ret = uri_to_str_url(&output->consumer->dst.net.control,
3868 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3869 if (ret < 0) {
3870 ret = -LTTNG_ERR_NOMEM;
3871 goto error;
3872 }
3873
3874 /* Data URI. */
3875 ret = uri_to_str_url(&output->consumer->dst.net.data,
3876 list[idx].data_url, sizeof(list[idx].data_url));
3877 if (ret < 0) {
3878 ret = -LTTNG_ERR_NOMEM;
3879 goto error;
3880 }
3881 }
3882 idx++;
3883 }
3884
3885 *outputs = list;
3886 list = NULL;
3887 ret = session->snapshot.nb_output;
3888 error:
3889 rcu_read_unlock();
3890 free(list);
3891 end:
3892 return ret;
3893 }
3894
3895 /*
3896 * Check if we can regenerate the metadata for this session.
3897 * Only kernel, UST per-uid and non-live sessions are supported.
3898 *
3899 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3900 */
3901 static
3902 int check_regenerate_metadata_support(struct ltt_session *session)
3903 {
3904 int ret;
3905
3906 assert(session);
3907
3908 if (session->live_timer != 0) {
3909 ret = LTTNG_ERR_LIVE_SESSION;
3910 goto end;
3911 }
3912 if (!session->active) {
3913 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3914 goto end;
3915 }
3916 if (session->ust_session) {
3917 switch (session->ust_session->buffer_type) {
3918 case LTTNG_BUFFER_PER_UID:
3919 break;
3920 case LTTNG_BUFFER_PER_PID:
3921 ret = LTTNG_ERR_PER_PID_SESSION;
3922 goto end;
3923 default:
3924 assert(0);
3925 ret = LTTNG_ERR_UNK;
3926 goto end;
3927 }
3928 }
3929 if (session->consumer->type == CONSUMER_DST_NET &&
3930 session->consumer->relay_minor_version < 8) {
3931 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
3932 goto end;
3933 }
3934 ret = 0;
3935
3936 end:
3937 return ret;
3938 }
3939
3940 static
3941 int clear_metadata_file(int fd)
3942 {
3943 int ret;
3944 off_t lseek_ret;
3945
3946 lseek_ret = lseek(fd, 0, SEEK_SET);
3947 if (lseek_ret < 0) {
3948 PERROR("lseek");
3949 ret = -1;
3950 goto end;
3951 }
3952
3953 ret = ftruncate(fd, 0);
3954 if (ret < 0) {
3955 PERROR("ftruncate");
3956 goto end;
3957 }
3958
3959 end:
3960 return ret;
3961 }
3962
3963 static
3964 int ust_regenerate_metadata(struct ltt_ust_session *usess)
3965 {
3966 int ret = 0;
3967 struct buffer_reg_uid *uid_reg = NULL;
3968 struct buffer_reg_session *session_reg = NULL;
3969
3970 rcu_read_lock();
3971 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
3972 struct ust_registry_session *registry;
3973 struct ust_registry_channel *chan;
3974 struct lttng_ht_iter iter_chan;
3975
3976 session_reg = uid_reg->registry;
3977 registry = session_reg->reg.ust;
3978
3979 pthread_mutex_lock(&registry->lock);
3980 registry->metadata_len_sent = 0;
3981 memset(registry->metadata, 0, registry->metadata_alloc_len);
3982 registry->metadata_len = 0;
3983 registry->metadata_version++;
3984 if (registry->metadata_fd > 0) {
3985 /* Clear the metadata file's content. */
3986 ret = clear_metadata_file(registry->metadata_fd);
3987 if (ret) {
3988 pthread_mutex_unlock(&registry->lock);
3989 goto end;
3990 }
3991 }
3992
3993 ret = ust_metadata_session_statedump(registry, NULL,
3994 registry->major, registry->minor);
3995 if (ret) {
3996 pthread_mutex_unlock(&registry->lock);
3997 ERR("Failed to generate session metadata (err = %d)",
3998 ret);
3999 goto end;
4000 }
4001 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
4002 chan, node.node) {
4003 struct ust_registry_event *event;
4004 struct lttng_ht_iter iter_event;
4005
4006 ret = ust_metadata_channel_statedump(registry, chan);
4007 if (ret) {
4008 pthread_mutex_unlock(&registry->lock);
4009 ERR("Failed to generate channel metadata "
4010 "(err = %d)", ret);
4011 goto end;
4012 }
4013 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
4014 event, node.node) {
4015 ret = ust_metadata_event_statedump(registry,
4016 chan, event);
4017 if (ret) {
4018 pthread_mutex_unlock(&registry->lock);
4019 ERR("Failed to generate event metadata "
4020 "(err = %d)", ret);
4021 goto end;
4022 }
4023 }
4024 }
4025 pthread_mutex_unlock(&registry->lock);
4026 }
4027
4028 end:
4029 rcu_read_unlock();
4030 return ret;
4031 }
4032
4033 /*
4034 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4035 *
4036 * Ask the consumer to truncate the existing metadata file(s) and
4037 * then regenerate the metadata. Live and per-pid sessions are not
4038 * supported and return an error.
4039 *
4040 * Return 0 on success or else a LTTNG_ERR code.
4041 */
4042 int cmd_regenerate_metadata(struct ltt_session *session)
4043 {
4044 int ret;
4045
4046 assert(session);
4047
4048 ret = check_regenerate_metadata_support(session);
4049 if (ret) {
4050 goto end;
4051 }
4052
4053 if (session->kernel_session) {
4054 ret = kernctl_session_regenerate_metadata(
4055 session->kernel_session->fd);
4056 if (ret < 0) {
4057 ERR("Failed to regenerate the kernel metadata");
4058 goto end;
4059 }
4060 }
4061
4062 if (session->ust_session) {
4063 ret = ust_regenerate_metadata(session->ust_session);
4064 if (ret < 0) {
4065 ERR("Failed to regenerate the UST metadata");
4066 goto end;
4067 }
4068 }
4069 DBG("Cmd metadata regenerate for session %s", session->name);
4070 ret = LTTNG_OK;
4071
4072 end:
4073 return ret;
4074 }
4075
4076 /*
4077 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4078 *
4079 * Ask the tracer to regenerate a new statedump.
4080 *
4081 * Return 0 on success or else a LTTNG_ERR code.
4082 */
4083 int cmd_regenerate_statedump(struct ltt_session *session)
4084 {
4085 int ret;
4086
4087 assert(session);
4088
4089 if (!session->active) {
4090 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4091 goto end;
4092 }
4093
4094 if (session->kernel_session) {
4095 ret = kernctl_session_regenerate_statedump(
4096 session->kernel_session->fd);
4097 /*
4098 * Currently, the statedump in kernel can only fail if out
4099 * of memory.
4100 */
4101 if (ret < 0) {
4102 if (ret == -ENOMEM) {
4103 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4104 } else {
4105 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4106 }
4107 ERR("Failed to regenerate the kernel statedump");
4108 goto end;
4109 }
4110 }
4111
4112 if (session->ust_session) {
4113 ret = ust_app_regenerate_statedump_all(session->ust_session);
4114 /*
4115 * Currently, the statedump in UST always returns 0.
4116 */
4117 if (ret < 0) {
4118 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4119 ERR("Failed to regenerate the UST statedump");
4120 goto end;
4121 }
4122 }
4123 DBG("Cmd regenerate statedump for session %s", session->name);
4124 ret = LTTNG_OK;
4125
4126 end:
4127 return ret;
4128 }
4129
4130 int cmd_register_trigger(struct command_ctx *cmd_ctx, int sock,
4131 struct notification_thread_handle *notification_thread)
4132 {
4133 int ret;
4134 size_t trigger_len;
4135 ssize_t sock_recv_len;
4136 struct lttng_trigger *trigger = NULL;
4137 struct lttng_buffer_view view;
4138 struct lttng_dynamic_buffer trigger_buffer;
4139
4140 lttng_dynamic_buffer_init(&trigger_buffer);
4141 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4142 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4143 if (ret) {
4144 ret = LTTNG_ERR_NOMEM;
4145 goto end;
4146 }
4147
4148 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4149 trigger_len);
4150 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4151 ERR("Failed to receive \"register trigger\" command payload");
4152 /* TODO: should this be a new error enum ? */
4153 ret = LTTNG_ERR_INVALID_TRIGGER;
4154 goto end;
4155 }
4156
4157 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4158 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4159 trigger_len) {
4160 ERR("Invalid trigger payload received in \"register trigger\" command");
4161 ret = LTTNG_ERR_INVALID_TRIGGER;
4162 goto end;
4163 }
4164
4165 ret = notification_thread_command_register_trigger(notification_thread,
4166 trigger);
4167 /* Ownership of trigger was transferred. */
4168 trigger = NULL;
4169 end:
4170 lttng_trigger_destroy(trigger);
4171 lttng_dynamic_buffer_reset(&trigger_buffer);
4172 return ret;
4173 }
4174
4175 int cmd_unregister_trigger(struct command_ctx *cmd_ctx, int sock,
4176 struct notification_thread_handle *notification_thread)
4177 {
4178 int ret;
4179 size_t trigger_len;
4180 ssize_t sock_recv_len;
4181 struct lttng_trigger *trigger = NULL;
4182 struct lttng_buffer_view view;
4183 struct lttng_dynamic_buffer trigger_buffer;
4184
4185 lttng_dynamic_buffer_init(&trigger_buffer);
4186 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4187 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4188 if (ret) {
4189 ret = LTTNG_ERR_NOMEM;
4190 goto end;
4191 }
4192
4193 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4194 trigger_len);
4195 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4196 ERR("Failed to receive \"unregister trigger\" command payload");
4197 /* TODO: should this be a new error enum ? */
4198 ret = LTTNG_ERR_INVALID_TRIGGER;
4199 goto end;
4200 }
4201
4202 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4203 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4204 trigger_len) {
4205 ERR("Invalid trigger payload received in \"unregister trigger\" command");
4206 ret = LTTNG_ERR_INVALID_TRIGGER;
4207 goto end;
4208 }
4209
4210 ret = notification_thread_command_unregister_trigger(notification_thread,
4211 trigger);
4212 end:
4213 lttng_trigger_destroy(trigger);
4214 lttng_dynamic_buffer_reset(&trigger_buffer);
4215 return ret;
4216 }
4217
4218 /*
4219 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4220 * snapshot output is *not* set with a remote destination.
4221 *
4222 * Return LTTNG_OK on success or a LTTNG_ERR code.
4223 */
4224 static enum lttng_error_code set_relayd_for_snapshot(
4225 struct consumer_output *output,
4226 const struct ltt_session *session)
4227 {
4228 enum lttng_error_code status = LTTNG_OK;
4229 struct lttng_ht_iter iter;
4230 struct consumer_socket *socket;
4231 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4232
4233 assert(output);
4234 assert(session);
4235
4236 DBG2("Set relayd object from snapshot output");
4237
4238 if (session->current_trace_chunk) {
4239 enum lttng_trace_chunk_status chunk_status =
4240 lttng_trace_chunk_get_id(
4241 session->current_trace_chunk,
4242 &current_chunk_id.value);
4243
4244 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
4245 current_chunk_id.is_set = true;
4246 } else {
4247 ERR("Failed to get current trace chunk id");
4248 status = LTTNG_ERR_UNK;
4249 goto error;
4250 }
4251 }
4252
4253 /* Ignore if snapshot consumer output is not network. */
4254 if (output->type != CONSUMER_DST_NET) {
4255 goto error;
4256 }
4257
4258 /*
4259 * For each consumer socket, create and send the relayd object of the
4260 * snapshot output.
4261 */
4262 rcu_read_lock();
4263 cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
4264 socket, node.node) {
4265 pthread_mutex_lock(socket->lock);
4266 status = send_consumer_relayd_sockets(0, session->id,
4267 output, socket,
4268 session->name, session->hostname,
4269 session->live_timer,
4270 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
4271 session->creation_time);
4272 pthread_mutex_unlock(socket->lock);
4273 if (status != LTTNG_OK) {
4274 rcu_read_unlock();
4275 goto error;
4276 }
4277 }
4278 rcu_read_unlock();
4279
4280 error:
4281 return status;
4282 }
4283
4284 /*
4285 * Record a kernel snapshot.
4286 *
4287 * Return LTTNG_OK on success or a LTTNG_ERR code.
4288 */
4289 static enum lttng_error_code record_kernel_snapshot(
4290 struct ltt_kernel_session *ksess,
4291 const struct consumer_output *output,
4292 const struct ltt_session *session,
4293 int wait, uint64_t nb_packets_per_stream)
4294 {
4295 enum lttng_error_code status;
4296
4297 assert(ksess);
4298 assert(output);
4299 assert(session);
4300
4301 status = kernel_snapshot_record(
4302 ksess, output, wait, nb_packets_per_stream);
4303 return status;
4304 }
4305
4306 /*
4307 * Record a UST snapshot.
4308 *
4309 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
4310 */
4311 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
4312 const struct consumer_output *output,
4313 const struct ltt_session *session,
4314 int wait, uint64_t nb_packets_per_stream)
4315 {
4316 enum lttng_error_code status;
4317
4318 assert(usess);
4319 assert(output);
4320 assert(session);
4321
4322 status = ust_app_snapshot_record(
4323 usess, output, wait, nb_packets_per_stream);
4324 return status;
4325 }
4326
4327 static
4328 uint64_t get_session_size_one_more_packet_per_stream(
4329 const struct ltt_session *session, uint64_t cur_nr_packets)
4330 {
4331 uint64_t tot_size = 0;
4332
4333 if (session->kernel_session) {
4334 struct ltt_kernel_channel *chan;
4335 const struct ltt_kernel_session *ksess =
4336 session->kernel_session;
4337
4338 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
4339 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
4340 /*
4341 * Don't take channel into account if we
4342 * already grab all its packets.
4343 */
4344 continue;
4345 }
4346 tot_size += chan->channel->attr.subbuf_size
4347 * chan->stream_count;
4348 }
4349 }
4350
4351 if (session->ust_session) {
4352 const struct ltt_ust_session *usess = session->ust_session;
4353
4354 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
4355 cur_nr_packets);
4356 }
4357
4358 return tot_size;
4359 }
4360
4361 /*
4362 * Calculate the number of packets we can grab from each stream that
4363 * fits within the overall snapshot max size.
4364 *
4365 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
4366 * the number of packets per stream.
4367 *
4368 * TODO: this approach is not perfect: we consider the worse case
4369 * (packet filling the sub-buffers) as an upper bound, but we could do
4370 * better if we do this calculation while we actually grab the packet
4371 * content: we would know how much padding we don't actually store into
4372 * the file.
4373 *
4374 * This algorithm is currently bounded by the number of packets per
4375 * stream.
4376 *
4377 * Since we call this algorithm before actually grabbing the data, it's
4378 * an approximation: for instance, applications could appear/disappear
4379 * in between this call and actually grabbing data.
4380 */
4381 static
4382 int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
4383 uint64_t max_size)
4384 {
4385 int64_t size_left;
4386 uint64_t cur_nb_packets = 0;
4387
4388 if (!max_size) {
4389 return 0; /* Infinite */
4390 }
4391
4392 size_left = max_size;
4393 for (;;) {
4394 uint64_t one_more_packet_tot_size;
4395
4396 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(
4397 session, cur_nb_packets);
4398 if (!one_more_packet_tot_size) {
4399 /* We are already grabbing all packets. */
4400 break;
4401 }
4402 size_left -= one_more_packet_tot_size;
4403 if (size_left < 0) {
4404 break;
4405 }
4406 cur_nb_packets++;
4407 }
4408 if (!cur_nb_packets) {
4409 /* Not enough room to grab one packet of each stream, error. */
4410 return -1;
4411 }
4412 return cur_nb_packets;
4413 }
4414
4415 static
4416 enum lttng_error_code snapshot_record(struct ltt_session *session,
4417 const struct snapshot_output *snapshot_output, int wait)
4418 {
4419 int64_t nb_packets_per_stream;
4420 char snapshot_chunk_name[LTTNG_NAME_MAX];
4421 int ret;
4422 enum lttng_error_code ret_code = LTTNG_OK;
4423 struct lttng_trace_chunk *snapshot_trace_chunk;
4424 struct consumer_output *original_ust_consumer_output = NULL;
4425 struct consumer_output *original_kernel_consumer_output = NULL;
4426 struct consumer_output *snapshot_ust_consumer_output = NULL;
4427 struct consumer_output *snapshot_kernel_consumer_output = NULL;
4428
4429 ret = snprintf(snapshot_chunk_name, sizeof(snapshot_chunk_name),
4430 "%s-%s-%" PRIu64,
4431 snapshot_output->name,
4432 snapshot_output->datetime,
4433 snapshot_output->nb_snapshot);
4434 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
4435 ERR("Failed to format snapshot name");
4436 ret_code = LTTNG_ERR_INVALID;
4437 goto error;
4438 }
4439 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
4440 snapshot_output->name, session->name,
4441 snapshot_chunk_name);
4442 if (!session->kernel_session && !session->ust_session) {
4443 ERR("Failed to record snapshot as no channels exist");
4444 ret_code = LTTNG_ERR_NO_CHANNEL;
4445 goto error;
4446 }
4447
4448 if (session->kernel_session) {
4449 original_kernel_consumer_output =
4450 session->kernel_session->consumer;
4451 snapshot_kernel_consumer_output =
4452 consumer_copy_output(snapshot_output->consumer);
4453 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
4454 original_kernel_consumer_output);
4455 if (ret < 0) {
4456 ERR("Failed to copy consumer sockets from snapshot output configuration");
4457 ret_code = LTTNG_ERR_NOMEM;
4458 goto error;
4459 }
4460 ret_code = set_relayd_for_snapshot(
4461 snapshot_kernel_consumer_output, session);
4462 if (ret_code != LTTNG_OK) {
4463 ERR("Failed to setup relay daemon for kernel tracer snapshot");
4464 goto error;
4465 }
4466 session->kernel_session->consumer =
4467 snapshot_kernel_consumer_output;
4468 }
4469 if (session->ust_session) {
4470 original_ust_consumer_output = session->ust_session->consumer;
4471 snapshot_ust_consumer_output =
4472 consumer_copy_output(snapshot_output->consumer);
4473 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
4474 original_ust_consumer_output);
4475 if (ret < 0) {
4476 ERR("Failed to copy consumer sockets from snapshot output configuration");
4477 ret_code = LTTNG_ERR_NOMEM;
4478 goto error;
4479 }
4480 ret_code = set_relayd_for_snapshot(
4481 snapshot_ust_consumer_output, session);
4482 if (ret_code != LTTNG_OK) {
4483 ERR("Failed to setup relay daemon for userspace tracer snapshot");
4484 goto error;
4485 }
4486 session->ust_session->consumer =
4487 snapshot_ust_consumer_output;
4488 }
4489
4490 snapshot_trace_chunk = session_create_new_trace_chunk(session,
4491 snapshot_kernel_consumer_output ?:
4492 snapshot_ust_consumer_output,
4493 consumer_output_get_base_path(
4494 snapshot_output->consumer),
4495 snapshot_chunk_name);
4496 if (!snapshot_trace_chunk) {
4497 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
4498 session->name);
4499 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
4500 goto error;
4501 }
4502 assert(!session->current_trace_chunk);
4503 ret = session_set_trace_chunk(session, snapshot_trace_chunk, NULL);
4504 lttng_trace_chunk_put(snapshot_trace_chunk);
4505 snapshot_trace_chunk = NULL;
4506 if (ret) {
4507 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
4508 session->name);
4509 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4510 goto error;
4511 }
4512
4513 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4514 snapshot_output->max_size);
4515 if (nb_packets_per_stream < 0) {
4516 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
4517 goto error;
4518 }
4519
4520 if (session->kernel_session) {
4521 ret_code = record_kernel_snapshot(session->kernel_session,
4522 snapshot_kernel_consumer_output, session,
4523 wait, nb_packets_per_stream);
4524 if (ret_code != LTTNG_OK) {
4525 goto error;
4526 }
4527 }
4528
4529 if (session->ust_session) {
4530 ret_code = record_ust_snapshot(session->ust_session,
4531 snapshot_ust_consumer_output, session,
4532 wait, nb_packets_per_stream);
4533 if (ret_code != LTTNG_OK) {
4534 goto error;
4535 }
4536 }
4537
4538 if (session_close_trace_chunk(
4539 session, session->current_trace_chunk, NULL)) {
4540 /*
4541 * Don't goto end; make sure the chunk is closed for the session
4542 * to allow future snapshots.
4543 */
4544 ERR("Failed to close snapshot trace chunk of session \"%s\"",
4545 session->name);
4546 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
4547 }
4548 if (session_set_trace_chunk(session, NULL, NULL)) {
4549 ERR("Failed to release the current trace chunk of session \"%s\"",
4550 session->name);
4551 ret_code = LTTNG_ERR_UNK;
4552 }
4553 error:
4554 if (original_ust_consumer_output) {
4555 session->ust_session->consumer = original_ust_consumer_output;
4556 }
4557 if (original_kernel_consumer_output) {
4558 session->kernel_session->consumer =
4559 original_kernel_consumer_output;
4560 }
4561 consumer_output_put(snapshot_ust_consumer_output);
4562 consumer_output_put(snapshot_kernel_consumer_output);
4563 return ret_code;
4564 }
4565
4566 /*
4567 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
4568 *
4569 * The wait parameter is ignored so this call always wait for the snapshot to
4570 * complete before returning.
4571 *
4572 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4573 */
4574 int cmd_snapshot_record(struct ltt_session *session,
4575 struct lttng_snapshot_output *output, int wait)
4576 {
4577 enum lttng_error_code cmd_ret = LTTNG_OK;
4578 int ret;
4579 unsigned int snapshot_success = 0;
4580 char datetime[16];
4581 struct snapshot_output *tmp_output = NULL;
4582
4583 assert(session);
4584 assert(output);
4585
4586 DBG("Cmd snapshot record for session %s", session->name);
4587
4588 /* Get the datetime for the snapshot output directory. */
4589 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
4590 sizeof(datetime));
4591 if (!ret) {
4592 cmd_ret = LTTNG_ERR_INVALID;
4593 goto error;
4594 }
4595
4596 /*
4597 * Permission denied to create an output if the session is not
4598 * set in no output mode.
4599 */
4600 if (session->output_traces) {
4601 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4602 goto error;
4603 }
4604
4605 /* The session needs to be started at least once. */
4606 if (!session->has_been_started) {
4607 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4608 goto error;
4609 }
4610
4611 /* Use temporary output for the session. */
4612 if (*output->ctrl_url != '\0') {
4613 tmp_output = snapshot_output_alloc();
4614 if (!tmp_output) {
4615 cmd_ret = LTTNG_ERR_NOMEM;
4616 goto error;
4617 }
4618
4619 ret = snapshot_output_init(session, output->max_size,
4620 output->name,
4621 output->ctrl_url, output->data_url,
4622 session->consumer,
4623 tmp_output, NULL);
4624 if (ret < 0) {
4625 if (ret == -ENOMEM) {
4626 cmd_ret = LTTNG_ERR_NOMEM;
4627 } else {
4628 cmd_ret = LTTNG_ERR_INVALID;
4629 }
4630 goto error;
4631 }
4632 /* Use the global session count for the temporary snapshot. */
4633 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
4634
4635 /* Use the global datetime */
4636 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
4637 cmd_ret = snapshot_record(session, tmp_output, wait);
4638 if (cmd_ret != LTTNG_OK) {
4639 goto error;
4640 }
4641 snapshot_success = 1;
4642 } else {
4643 struct snapshot_output *sout;
4644 struct lttng_ht_iter iter;
4645
4646 rcu_read_lock();
4647 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
4648 &iter.iter, sout, node.node) {
4649 struct snapshot_output output_copy;
4650
4651 /*
4652 * Make a local copy of the output and override output
4653 * parameters with those provided as part of the
4654 * command.
4655 */
4656 memcpy(&output_copy, sout, sizeof(output_copy));
4657
4658 if (output->max_size != (uint64_t) -1ULL) {
4659 output_copy.max_size = output->max_size;
4660 }
4661
4662 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
4663 memcpy(output_copy.datetime, datetime,
4664 sizeof(datetime));
4665
4666 /* Use temporary name. */
4667 if (*output->name != '\0') {
4668 if (lttng_strncpy(output_copy.name,
4669 output->name,
4670 sizeof(output_copy.name))) {
4671 cmd_ret = LTTNG_ERR_INVALID;
4672 rcu_read_unlock();
4673 goto error;
4674 }
4675 }
4676
4677 cmd_ret = snapshot_record(session, &output_copy, wait);
4678 if (cmd_ret != LTTNG_OK) {
4679 rcu_read_unlock();
4680 goto error;
4681 }
4682 snapshot_success = 1;
4683 }
4684 rcu_read_unlock();
4685 }
4686
4687 if (snapshot_success) {
4688 session->snapshot.nb_snapshot++;
4689 } else {
4690 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
4691 }
4692
4693 error:
4694 if (tmp_output) {
4695 snapshot_output_destroy(tmp_output);
4696 }
4697 return cmd_ret;
4698 }
4699
4700 /*
4701 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
4702 */
4703 int cmd_set_session_shm_path(struct ltt_session *session,
4704 const char *shm_path)
4705 {
4706 /* Safety net */
4707 assert(session);
4708
4709 /*
4710 * Can only set shm path before session is started.
4711 */
4712 if (session->has_been_started) {
4713 return LTTNG_ERR_SESSION_STARTED;
4714 }
4715
4716 strncpy(session->shm_path, shm_path,
4717 sizeof(session->shm_path));
4718 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
4719
4720 return 0;
4721 }
4722
4723 /*
4724 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
4725 *
4726 * Ask the consumer to rotate the session output directory.
4727 * The session lock must be held.
4728 *
4729 * Returns LTTNG_OK on success or else a negative LTTng error code.
4730 */
4731 int cmd_rotate_session(struct ltt_session *session,
4732 struct lttng_rotate_session_return *rotate_return,
4733 bool quiet_rotation)
4734 {
4735 int ret;
4736 uint64_t ongoing_rotation_chunk_id;
4737 enum lttng_error_code cmd_ret = LTTNG_OK;
4738 struct lttng_trace_chunk *chunk_being_archived = NULL;
4739 struct lttng_trace_chunk *new_trace_chunk = NULL;
4740 enum lttng_trace_chunk_status chunk_status;
4741
4742 assert(session);
4743
4744 if (!session->has_been_started) {
4745 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4746 goto end;
4747 }
4748
4749 if (session->live_timer || !session->output_traces) {
4750 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
4751 goto end;
4752 }
4753
4754 /* Unsupported feature in lttng-relayd before 2.11. */
4755 if (session->consumer->type == CONSUMER_DST_NET &&
4756 (session->consumer->relay_major_version == 2 &&
4757 session->consumer->relay_minor_version < 11)) {
4758 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
4759 goto end;
4760 }
4761
4762 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
4763 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
4764 session->name);
4765 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
4766 goto end;
4767 }
4768
4769 /*
4770 * After a stop, we only allow one rotation to occur, the other ones are
4771 * useless until a new start.
4772 */
4773 if (session->rotated_after_last_stop) {
4774 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
4775 session->name);
4776 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
4777 goto end;
4778 }
4779
4780 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
4781
4782 if (session->active) {
4783 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
4784 NULL, NULL);
4785 if (!new_trace_chunk) {
4786 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
4787 goto error;
4788 }
4789 }
4790
4791 /* The current trace chunk becomes the chunk being archived. */
4792 ret = session_set_trace_chunk(session, new_trace_chunk,
4793 &chunk_being_archived);
4794 if (ret) {
4795 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4796 goto error;
4797 }
4798
4799 assert(chunk_being_archived);
4800 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
4801 &ongoing_rotation_chunk_id);
4802 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
4803
4804 if (session->kernel_session) {
4805 cmd_ret = kernel_rotate_session(session);
4806 if (cmd_ret != LTTNG_OK) {
4807 goto error;
4808 }
4809 }
4810 if (session->ust_session) {
4811 cmd_ret = ust_app_rotate_session(session);
4812 if (cmd_ret != LTTNG_OK) {
4813 goto error;
4814 }
4815 }
4816
4817 ret = session_close_trace_chunk(session, chunk_being_archived,
4818 quiet_rotation ?
4819 NULL :
4820 &((enum lttng_trace_chunk_command_type){
4821 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED}));
4822 if (ret) {
4823 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
4824 goto error;
4825 }
4826
4827 session->quiet_rotation = quiet_rotation;
4828 ret = timer_session_rotation_pending_check_start(session,
4829 DEFAULT_ROTATE_PENDING_TIMER);
4830 if (ret) {
4831 cmd_ret = LTTNG_ERR_UNK;
4832 goto error;
4833 }
4834
4835 if (!session->active) {
4836 session->rotated_after_last_stop = true;
4837 }
4838
4839 if (rotate_return) {
4840 rotate_return->rotation_id = ongoing_rotation_chunk_id;
4841 }
4842
4843 session->chunk_being_archived = chunk_being_archived;
4844 chunk_being_archived = NULL;
4845 if (!quiet_rotation) {
4846 ret = notification_thread_command_session_rotation_ongoing(
4847 notification_thread_handle,
4848 session->name, session->uid, session->gid,
4849 ongoing_rotation_chunk_id);
4850 if (ret != LTTNG_OK) {
4851 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
4852 session->name);
4853 cmd_ret = ret;
4854 }
4855 }
4856
4857 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
4858 session->name, ongoing_rotation_chunk_id);
4859 end:
4860 lttng_trace_chunk_put(new_trace_chunk);
4861 lttng_trace_chunk_put(chunk_being_archived);
4862 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
4863 return ret;
4864 error:
4865 if (session_reset_rotation_state(session,
4866 LTTNG_ROTATION_STATE_ERROR)) {
4867 ERR("Failed to reset rotation state of session \"%s\"",
4868 session->name);
4869 }
4870 goto end;
4871 }
4872
4873 /*
4874 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
4875 *
4876 * Check if the session has finished its rotation.
4877 *
4878 * Return LTTNG_OK on success or else an LTTNG_ERR code.
4879 */
4880 int cmd_rotate_get_info(struct ltt_session *session,
4881 struct lttng_rotation_get_info_return *info_return,
4882 uint64_t rotation_id)
4883 {
4884 enum lttng_error_code cmd_ret = LTTNG_OK;
4885 enum lttng_rotation_state rotation_state;
4886
4887 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
4888 session->most_recent_chunk_id.value);
4889
4890 if (session->chunk_being_archived) {
4891 enum lttng_trace_chunk_status chunk_status;
4892 uint64_t chunk_id;
4893
4894 chunk_status = lttng_trace_chunk_get_id(
4895 session->chunk_being_archived,
4896 &chunk_id);
4897 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
4898
4899 rotation_state = rotation_id == chunk_id ?
4900 LTTNG_ROTATION_STATE_ONGOING :
4901 LTTNG_ROTATION_STATE_EXPIRED;
4902 } else {
4903 if (session->last_archived_chunk_id.is_set &&
4904 rotation_id != session->last_archived_chunk_id.value) {
4905 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
4906 } else {
4907 rotation_state = session->rotation_state;
4908 }
4909 }
4910
4911 switch (rotation_state) {
4912 case LTTNG_ROTATION_STATE_NO_ROTATION:
4913 DBG("Reporting that no rotation has occured within the lifetime of session \"%s\"",
4914 session->name);
4915 goto end;
4916 case LTTNG_ROTATION_STATE_EXPIRED:
4917 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
4918 rotation_id, session->name);
4919 break;
4920 case LTTNG_ROTATION_STATE_ONGOING:
4921 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
4922 rotation_id, session->name);
4923 break;
4924 case LTTNG_ROTATION_STATE_COMPLETED:
4925 {
4926 int fmt_ret;
4927 char *chunk_path;
4928 char *current_tracing_path_reply;
4929 size_t current_tracing_path_reply_len;
4930
4931 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
4932 rotation_id, session->name);
4933
4934 switch (session_get_consumer_destination_type(session)) {
4935 case CONSUMER_DST_LOCAL:
4936 current_tracing_path_reply =
4937 info_return->location.local.absolute_path;
4938 current_tracing_path_reply_len =
4939 sizeof(info_return->location.local.absolute_path);
4940 info_return->location_type =
4941 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
4942 break;
4943 case CONSUMER_DST_NET:
4944 current_tracing_path_reply =
4945 info_return->location.relay.relative_path;
4946 current_tracing_path_reply_len =
4947 sizeof(info_return->location.relay.relative_path);
4948 /* Currently the only supported relay protocol. */
4949 info_return->location.relay.protocol =
4950 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
4951
4952 fmt_ret = lttng_strncpy(info_return->location.relay.host,
4953 session_get_net_consumer_hostname(session),
4954 sizeof(info_return->location.relay.host));
4955 if (fmt_ret) {
4956 ERR("Failed to copy host name to rotate_get_info reply");
4957 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
4958 cmd_ret = LTTNG_ERR_SET_URL;
4959 goto end;
4960 }
4961
4962 session_get_net_consumer_ports(session,
4963 &info_return->location.relay.ports.control,
4964 &info_return->location.relay.ports.data);
4965 info_return->location_type =
4966 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
4967 break;
4968 default:
4969 abort();
4970 }
4971 fmt_ret = asprintf(&chunk_path,
4972 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
4973 session_get_base_path(session),
4974 session->last_archived_chunk_name);
4975 if (fmt_ret == -1) {
4976 PERROR("Failed to format the path of the last archived trace chunk");
4977 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
4978 cmd_ret = LTTNG_ERR_UNK;
4979 goto end;
4980 }
4981
4982 fmt_ret = lttng_strncpy(current_tracing_path_reply,
4983 chunk_path, current_tracing_path_reply_len);
4984 free(chunk_path);
4985 if (fmt_ret) {
4986 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
4987 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
4988 cmd_ret = LTTNG_ERR_UNK;
4989 goto end;
4990 }
4991
4992 break;
4993 }
4994 case LTTNG_ROTATION_STATE_ERROR:
4995 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
4996 rotation_id, session->name);
4997 break;
4998 default:
4999 abort();
5000 }
5001
5002 cmd_ret = LTTNG_OK;
5003 end:
5004 info_return->status = (int32_t) rotation_state;
5005 return cmd_ret;
5006 }
5007
5008 /*
5009 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5010 *
5011 * Configure the automatic rotation parameters.
5012 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5013 * 'activate' to false means deactivate the rotation schedule and validate that
5014 * 'new_value' has the same value as the currently active value.
5015 *
5016 * Return 0 on success or else a positive LTTNG_ERR code.
5017 */
5018 int cmd_rotation_set_schedule(struct ltt_session *session,
5019 bool activate, enum lttng_rotation_schedule_type schedule_type,
5020 uint64_t new_value,
5021 struct notification_thread_handle *notification_thread_handle)
5022 {
5023 int ret;
5024 uint64_t *parameter_value;
5025
5026 assert(session);
5027
5028 DBG("Cmd rotate set schedule session %s", session->name);
5029
5030 if (session->live_timer || !session->output_traces) {
5031 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5032 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5033 goto end;
5034 }
5035
5036 switch (schedule_type) {
5037 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5038 parameter_value = &session->rotate_size;
5039 break;
5040 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5041 parameter_value = &session->rotate_timer_period;
5042 if (new_value >= UINT_MAX) {
5043 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5044 new_value, UINT_MAX);
5045 ret = LTTNG_ERR_INVALID;
5046 goto end;
5047 }
5048 break;
5049 default:
5050 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5051 ret = LTTNG_ERR_INVALID;
5052 goto end;
5053 }
5054
5055 /* Improper use of the API. */
5056 if (new_value == -1ULL) {
5057 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5058 ret = LTTNG_ERR_INVALID;
5059 goto end;
5060 }
5061
5062 /*
5063 * As indicated in struct ltt_session's comments, a value of == 0 means
5064 * this schedule rotation type is not in use.
5065 *
5066 * Reject the command if we were asked to activate a schedule that was
5067 * already active.
5068 */
5069 if (activate && *parameter_value != 0) {
5070 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5071 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5072 goto end;
5073 }
5074
5075 /*
5076 * Reject the command if we were asked to deactivate a schedule that was
5077 * not active.
5078 */
5079 if (!activate && *parameter_value == 0) {
5080 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5081 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5082 goto end;
5083 }
5084
5085 /*
5086 * Reject the command if we were asked to deactivate a schedule that
5087 * doesn't exist.
5088 */
5089 if (!activate && *parameter_value != new_value) {
5090 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5091 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5092 goto end;
5093 }
5094
5095 *parameter_value = activate ? new_value : 0;
5096
5097 switch (schedule_type) {
5098 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5099 if (activate && session->active) {
5100 /*
5101 * Only start the timer if the session is active,
5102 * otherwise it will be started when the session starts.
5103 */
5104 ret = timer_session_rotation_schedule_timer_start(
5105 session, new_value);
5106 if (ret) {
5107 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5108 ret = LTTNG_ERR_UNK;
5109 goto end;
5110 }
5111 } else {
5112 ret = timer_session_rotation_schedule_timer_stop(
5113 session);
5114 if (ret) {
5115 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5116 ret = LTTNG_ERR_UNK;
5117 goto end;
5118 }
5119 }
5120 break;
5121 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5122 if (activate) {
5123 ret = subscribe_session_consumed_size_rotation(session,
5124 new_value, notification_thread_handle);
5125 if (ret) {
5126 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5127 ret = LTTNG_ERR_UNK;
5128 goto end;
5129 }
5130 } else {
5131 ret = unsubscribe_session_consumed_size_rotation(session,
5132 notification_thread_handle);
5133 if (ret) {
5134 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5135 ret = LTTNG_ERR_UNK;
5136 goto end;
5137 }
5138
5139 }
5140 break;
5141 default:
5142 /* Would have been caught before. */
5143 abort();
5144 }
5145
5146 ret = LTTNG_OK;
5147
5148 goto end;
5149
5150 end:
5151 return ret;
5152 }
5153
5154 /* Wait for a given path to be removed before continuing. */
5155 static enum lttng_error_code wait_on_path(void *path_data)
5156 {
5157 const char *shm_path = path_data;
5158
5159 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
5160 shm_path);
5161 while (true) {
5162 int ret;
5163 struct stat st;
5164
5165 ret = stat(shm_path, &st);
5166 if (ret) {
5167 if (errno != ENOENT) {
5168 PERROR("stat() returned an error while checking for the existence of the shm path");
5169 } else {
5170 DBG("shm path no longer exists, completing the destruction of session");
5171 }
5172 break;
5173 } else {
5174 if (!S_ISDIR(st.st_mode)) {
5175 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5176 shm_path);
5177 break;
5178 }
5179 }
5180 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5181 }
5182 return LTTNG_OK;
5183 }
5184
5185 /*
5186 * Returns a pointer to a handler to run on completion of a command.
5187 * Returns NULL if no handler has to be run for the last command executed.
5188 */
5189 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
5190 {
5191 struct cmd_completion_handler *handler = current_completion_handler;
5192
5193 current_completion_handler = NULL;
5194 return handler;
5195 }
5196
5197 /*
5198 * Init command subsystem.
5199 */
5200 void cmd_init(void)
5201 {
5202 /*
5203 * Set network sequence index to 1 for streams to match a relayd
5204 * socket on the consumer side.
5205 */
5206 pthread_mutex_lock(&relayd_net_seq_idx_lock);
5207 relayd_net_seq_idx = 1;
5208 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
5209
5210 DBG("Command subsystem initialized");
5211 }
LTTng tools - Deliverables
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