c2231f1b07f128de561fd1849ed845c00fc91483
[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 const 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 if (ret) {
916 ret_code = LTTNG_ERR_FATAL;
917 goto error;
918 }
919 consumer->type = CONSUMER_DST_LOCAL;
920 break;
921 }
922
923 ret_code = LTTNG_OK;
924 error:
925 return ret_code;
926 }
927
928 /*
929 * Init tracing by creating trace directory and sending fds kernel consumer.
930 */
931 static int init_kernel_tracing(struct ltt_kernel_session *session)
932 {
933 int ret = 0;
934 struct lttng_ht_iter iter;
935 struct consumer_socket *socket;
936
937 assert(session);
938
939 rcu_read_lock();
940
941 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
942 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
943 socket, node.node) {
944 pthread_mutex_lock(socket->lock);
945 ret = kernel_consumer_send_session(socket, session);
946 pthread_mutex_unlock(socket->lock);
947 if (ret < 0) {
948 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
949 goto error;
950 }
951 }
952 }
953
954 error:
955 rcu_read_unlock();
956 return ret;
957 }
958
959 /*
960 * Create a socket to the relayd using the URI.
961 *
962 * On success, the relayd_sock pointer is set to the created socket.
963 * Else, it remains untouched and an LTTng error code is returned.
964 */
965 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
966 struct lttcomm_relayd_sock **relayd_sock,
967 struct consumer_output *consumer)
968 {
969 int ret;
970 enum lttng_error_code status = LTTNG_OK;
971 struct lttcomm_relayd_sock *rsock;
972
973 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
974 RELAYD_VERSION_COMM_MINOR);
975 if (!rsock) {
976 status = LTTNG_ERR_FATAL;
977 goto error;
978 }
979
980 /*
981 * Connect to relayd so we can proceed with a session creation. This call
982 * can possibly block for an arbitrary amount of time to set the health
983 * state to be in poll execution.
984 */
985 health_poll_entry();
986 ret = relayd_connect(rsock);
987 health_poll_exit();
988 if (ret < 0) {
989 ERR("Unable to reach lttng-relayd");
990 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
991 goto free_sock;
992 }
993
994 /* Create socket for control stream. */
995 if (uri->stype == LTTNG_STREAM_CONTROL) {
996 DBG3("Creating relayd stream socket from URI");
997
998 /* Check relayd version */
999 ret = relayd_version_check(rsock);
1000 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
1001 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
1002 goto close_sock;
1003 } else if (ret < 0) {
1004 ERR("Unable to reach lttng-relayd");
1005 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1006 goto close_sock;
1007 }
1008 consumer->relay_major_version = rsock->major;
1009 consumer->relay_minor_version = rsock->minor;
1010 } else if (uri->stype == LTTNG_STREAM_DATA) {
1011 DBG3("Creating relayd data socket from URI");
1012 } else {
1013 /* Command is not valid */
1014 ERR("Relayd invalid stream type: %d", uri->stype);
1015 status = LTTNG_ERR_INVALID;
1016 goto close_sock;
1017 }
1018
1019 *relayd_sock = rsock;
1020
1021 return status;
1022
1023 close_sock:
1024 /* The returned value is not useful since we are on an error path. */
1025 (void) relayd_close(rsock);
1026 free_sock:
1027 free(rsock);
1028 error:
1029 return status;
1030 }
1031
1032 /*
1033 * Connect to the relayd using URI and send the socket to the right consumer.
1034 *
1035 * The consumer socket lock must be held by the caller.
1036 *
1037 * Returns LTTNG_OK on success or an LTTng error code on failure.
1038 */
1039 static enum lttng_error_code send_consumer_relayd_socket(
1040 unsigned int session_id,
1041 struct lttng_uri *relayd_uri,
1042 struct consumer_output *consumer,
1043 struct consumer_socket *consumer_sock,
1044 const char *session_name, const char *hostname,
1045 const char *base_path, int session_live_timer,
1046 const uint64_t *current_chunk_id,
1047 time_t session_creation_time,
1048 bool session_name_contains_creation_time)
1049 {
1050 int ret;
1051 struct lttcomm_relayd_sock *rsock = NULL;
1052 enum lttng_error_code status;
1053
1054 /* Connect to relayd and make version check if uri is the control. */
1055 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1056 if (status != LTTNG_OK) {
1057 goto relayd_comm_error;
1058 }
1059 assert(rsock);
1060
1061 /* Set the network sequence index if not set. */
1062 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1063 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1064 /*
1065 * Increment net_seq_idx because we are about to transfer the
1066 * new relayd socket to the consumer.
1067 * Assign unique key so the consumer can match streams.
1068 */
1069 consumer->net_seq_index = ++relayd_net_seq_idx;
1070 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1071 }
1072
1073 /* Send relayd socket to consumer. */
1074 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1075 relayd_uri->stype, session_id,
1076 session_name, hostname, base_path,
1077 session_live_timer, current_chunk_id,
1078 session_creation_time, session_name_contains_creation_time);
1079 if (ret < 0) {
1080 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1081 goto close_sock;
1082 }
1083
1084 /* Flag that the corresponding socket was sent. */
1085 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1086 consumer_sock->control_sock_sent = 1;
1087 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1088 consumer_sock->data_sock_sent = 1;
1089 }
1090
1091 /*
1092 * Close socket which was dup on the consumer side. The session daemon does
1093 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1094 */
1095
1096 close_sock:
1097 if (status != LTTNG_OK) {
1098 /*
1099 * The consumer output for this session should not be used anymore
1100 * since the relayd connection failed thus making any tracing or/and
1101 * streaming not usable.
1102 */
1103 consumer->enabled = 0;
1104 }
1105 (void) relayd_close(rsock);
1106 free(rsock);
1107
1108 relayd_comm_error:
1109 return status;
1110 }
1111
1112 /*
1113 * Send both relayd sockets to a specific consumer and domain. This is a
1114 * helper function to facilitate sending the information to the consumer for a
1115 * session.
1116 *
1117 * The consumer socket lock must be held by the caller.
1118 *
1119 * Returns LTTNG_OK, or an LTTng error code on failure.
1120 */
1121 static enum lttng_error_code send_consumer_relayd_sockets(
1122 enum lttng_domain_type domain,
1123 unsigned int session_id, struct consumer_output *consumer,
1124 struct consumer_socket *sock, const char *session_name,
1125 const char *hostname, const char *base_path, int session_live_timer,
1126 const uint64_t *current_chunk_id, time_t session_creation_time,
1127 bool session_name_contains_creation_time)
1128 {
1129 enum lttng_error_code status = LTTNG_OK;
1130
1131 assert(consumer);
1132 assert(sock);
1133
1134 /* Sending control relayd socket. */
1135 if (!sock->control_sock_sent) {
1136 status = send_consumer_relayd_socket(session_id,
1137 &consumer->dst.net.control, consumer, sock,
1138 session_name, hostname, base_path, session_live_timer,
1139 current_chunk_id, session_creation_time,
1140 session_name_contains_creation_time);
1141 if (status != LTTNG_OK) {
1142 goto error;
1143 }
1144 }
1145
1146 /* Sending data relayd socket. */
1147 if (!sock->data_sock_sent) {
1148 status = send_consumer_relayd_socket(session_id,
1149 &consumer->dst.net.data, consumer, sock,
1150 session_name, hostname, base_path, session_live_timer,
1151 current_chunk_id, session_creation_time,
1152 session_name_contains_creation_time);
1153 if (status != LTTNG_OK) {
1154 goto error;
1155 }
1156 }
1157
1158 error:
1159 return status;
1160 }
1161
1162 /*
1163 * Setup relayd connections for a tracing session. First creates the socket to
1164 * the relayd and send them to the right domain consumer. Consumer type MUST be
1165 * network.
1166 */
1167 int cmd_setup_relayd(struct ltt_session *session)
1168 {
1169 int ret = LTTNG_OK;
1170 struct ltt_ust_session *usess;
1171 struct ltt_kernel_session *ksess;
1172 struct consumer_socket *socket;
1173 struct lttng_ht_iter iter;
1174 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1175
1176 assert(session);
1177
1178 usess = session->ust_session;
1179 ksess = session->kernel_session;
1180
1181 DBG("Setting relayd for session %s", session->name);
1182
1183 if (session->current_trace_chunk) {
1184 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1185 session->current_trace_chunk, &current_chunk_id.value);
1186
1187 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1188 current_chunk_id.is_set = true;
1189 } else {
1190 ERR("Failed to get current trace chunk id");
1191 ret = LTTNG_ERR_UNK;
1192 goto error;
1193 }
1194 }
1195
1196 rcu_read_lock();
1197
1198 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1199 && usess->consumer->enabled) {
1200 /* For each consumer socket, send relayd sockets */
1201 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1202 socket, node.node) {
1203 pthread_mutex_lock(socket->lock);
1204 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1205 usess->consumer, socket,
1206 session->name, session->hostname,
1207 session->base_path,
1208 session->live_timer,
1209 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1210 session->creation_time,
1211 session->name_contains_creation_time);
1212 pthread_mutex_unlock(socket->lock);
1213 if (ret != LTTNG_OK) {
1214 goto error;
1215 }
1216 /* Session is now ready for network streaming. */
1217 session->net_handle = 1;
1218 }
1219 session->consumer->relay_major_version =
1220 usess->consumer->relay_major_version;
1221 session->consumer->relay_minor_version =
1222 usess->consumer->relay_minor_version;
1223 }
1224
1225 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1226 && ksess->consumer->enabled) {
1227 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1228 socket, node.node) {
1229 pthread_mutex_lock(socket->lock);
1230 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1231 ksess->consumer, socket,
1232 session->name, session->hostname,
1233 session->base_path,
1234 session->live_timer,
1235 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1236 session->creation_time,
1237 session->name_contains_creation_time);
1238 pthread_mutex_unlock(socket->lock);
1239 if (ret != LTTNG_OK) {
1240 goto error;
1241 }
1242 /* Session is now ready for network streaming. */
1243 session->net_handle = 1;
1244 }
1245 session->consumer->relay_major_version =
1246 ksess->consumer->relay_major_version;
1247 session->consumer->relay_minor_version =
1248 ksess->consumer->relay_minor_version;
1249 }
1250
1251 error:
1252 rcu_read_unlock();
1253 return ret;
1254 }
1255
1256 /*
1257 * Start a kernel session by opening all necessary streams.
1258 */
1259 static int start_kernel_session(struct ltt_kernel_session *ksess)
1260 {
1261 int ret;
1262 struct ltt_kernel_channel *kchan;
1263
1264 /* Open kernel metadata */
1265 if (ksess->metadata == NULL && ksess->output_traces) {
1266 ret = kernel_open_metadata(ksess);
1267 if (ret < 0) {
1268 ret = LTTNG_ERR_KERN_META_FAIL;
1269 goto error;
1270 }
1271 }
1272
1273 /* Open kernel metadata stream */
1274 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1275 ret = kernel_open_metadata_stream(ksess);
1276 if (ret < 0) {
1277 ERR("Kernel create metadata stream failed");
1278 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1279 goto error;
1280 }
1281 }
1282
1283 /* For each channel */
1284 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1285 if (kchan->stream_count == 0) {
1286 ret = kernel_open_channel_stream(kchan);
1287 if (ret < 0) {
1288 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1289 goto error;
1290 }
1291 /* Update the stream global counter */
1292 ksess->stream_count_global += ret;
1293 }
1294 }
1295
1296 /* Setup kernel consumer socket and send fds to it */
1297 ret = init_kernel_tracing(ksess);
1298 if (ret != 0) {
1299 ret = LTTNG_ERR_KERN_START_FAIL;
1300 goto error;
1301 }
1302
1303 /* This start the kernel tracing */
1304 ret = kernel_start_session(ksess);
1305 if (ret < 0) {
1306 ret = LTTNG_ERR_KERN_START_FAIL;
1307 goto error;
1308 }
1309
1310 /* Quiescent wait after starting trace */
1311 kernel_wait_quiescent();
1312
1313 ksess->active = 1;
1314
1315 ret = LTTNG_OK;
1316
1317 error:
1318 return ret;
1319 }
1320
1321 /*
1322 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1323 */
1324 int cmd_disable_channel(struct ltt_session *session,
1325 enum lttng_domain_type domain, char *channel_name)
1326 {
1327 int ret;
1328 struct ltt_ust_session *usess;
1329
1330 usess = session->ust_session;
1331
1332 rcu_read_lock();
1333
1334 switch (domain) {
1335 case LTTNG_DOMAIN_KERNEL:
1336 {
1337 ret = channel_kernel_disable(session->kernel_session,
1338 channel_name);
1339 if (ret != LTTNG_OK) {
1340 goto error;
1341 }
1342
1343 kernel_wait_quiescent();
1344 break;
1345 }
1346 case LTTNG_DOMAIN_UST:
1347 {
1348 struct ltt_ust_channel *uchan;
1349 struct lttng_ht *chan_ht;
1350
1351 chan_ht = usess->domain_global.channels;
1352
1353 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1354 if (uchan == NULL) {
1355 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1356 goto error;
1357 }
1358
1359 ret = channel_ust_disable(usess, uchan);
1360 if (ret != LTTNG_OK) {
1361 goto error;
1362 }
1363 break;
1364 }
1365 default:
1366 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1367 goto error;
1368 }
1369
1370 ret = LTTNG_OK;
1371
1372 error:
1373 rcu_read_unlock();
1374 return ret;
1375 }
1376
1377 /*
1378 * Command LTTNG_TRACK_PID processed by the client thread.
1379 *
1380 * Called with session lock held.
1381 */
1382 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1383 int pid)
1384 {
1385 int ret;
1386
1387 rcu_read_lock();
1388
1389 switch (domain) {
1390 case LTTNG_DOMAIN_KERNEL:
1391 {
1392 struct ltt_kernel_session *ksess;
1393
1394 ksess = session->kernel_session;
1395
1396 ret = kernel_track_pid(ksess, pid);
1397 if (ret != LTTNG_OK) {
1398 goto error;
1399 }
1400
1401 kernel_wait_quiescent();
1402 break;
1403 }
1404 case LTTNG_DOMAIN_UST:
1405 {
1406 struct ltt_ust_session *usess;
1407
1408 usess = session->ust_session;
1409
1410 ret = trace_ust_track_pid(usess, pid);
1411 if (ret != LTTNG_OK) {
1412 goto error;
1413 }
1414 break;
1415 }
1416 default:
1417 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1418 goto error;
1419 }
1420
1421 ret = LTTNG_OK;
1422
1423 error:
1424 rcu_read_unlock();
1425 return ret;
1426 }
1427
1428 /*
1429 * Command LTTNG_UNTRACK_PID processed by the client thread.
1430 *
1431 * Called with session lock held.
1432 */
1433 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1434 int pid)
1435 {
1436 int ret;
1437
1438 rcu_read_lock();
1439
1440 switch (domain) {
1441 case LTTNG_DOMAIN_KERNEL:
1442 {
1443 struct ltt_kernel_session *ksess;
1444
1445 ksess = session->kernel_session;
1446
1447 ret = kernel_untrack_pid(ksess, pid);
1448 if (ret != LTTNG_OK) {
1449 goto error;
1450 }
1451
1452 kernel_wait_quiescent();
1453 break;
1454 }
1455 case LTTNG_DOMAIN_UST:
1456 {
1457 struct ltt_ust_session *usess;
1458
1459 usess = session->ust_session;
1460
1461 ret = trace_ust_untrack_pid(usess, pid);
1462 if (ret != LTTNG_OK) {
1463 goto error;
1464 }
1465 break;
1466 }
1467 default:
1468 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1469 goto error;
1470 }
1471
1472 ret = LTTNG_OK;
1473
1474 error:
1475 rcu_read_unlock();
1476 return ret;
1477 }
1478
1479 /*
1480 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1481 *
1482 * The wpipe arguments is used as a notifier for the kernel thread.
1483 */
1484 int cmd_enable_channel(struct ltt_session *session,
1485 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1486 {
1487 int ret;
1488 struct ltt_ust_session *usess = session->ust_session;
1489 struct lttng_ht *chan_ht;
1490 size_t len;
1491 struct lttng_channel attr;
1492
1493 assert(session);
1494 assert(_attr);
1495 assert(domain);
1496
1497 attr = *_attr;
1498 len = lttng_strnlen(attr.name, sizeof(attr.name));
1499
1500 /* Validate channel name */
1501 if (attr.name[0] == '.' ||
1502 memchr(attr.name, '/', len) != NULL) {
1503 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1504 goto end;
1505 }
1506
1507 DBG("Enabling channel %s for session %s", attr.name, session->name);
1508
1509 rcu_read_lock();
1510
1511 /*
1512 * Don't try to enable a channel if the session has been started at
1513 * some point in time before. The tracer does not allow it.
1514 */
1515 if (session->has_been_started) {
1516 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1517 goto error;
1518 }
1519
1520 /*
1521 * If the session is a live session, remove the switch timer, the
1522 * live timer does the same thing but sends also synchronisation
1523 * beacons for inactive streams.
1524 */
1525 if (session->live_timer > 0) {
1526 attr.attr.live_timer_interval = session->live_timer;
1527 attr.attr.switch_timer_interval = 0;
1528 }
1529
1530 /* Check for feature support */
1531 switch (domain->type) {
1532 case LTTNG_DOMAIN_KERNEL:
1533 {
1534 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1535 /* Sampling position of buffer is not supported */
1536 WARN("Kernel tracer does not support buffer monitoring. "
1537 "Setting the monitor interval timer to 0 "
1538 "(disabled) for channel '%s' of session '%s'",
1539 attr.name, session->name);
1540 lttng_channel_set_monitor_timer_interval(&attr, 0);
1541 }
1542 break;
1543 }
1544 case LTTNG_DOMAIN_UST:
1545 break;
1546 case LTTNG_DOMAIN_JUL:
1547 case LTTNG_DOMAIN_LOG4J:
1548 case LTTNG_DOMAIN_PYTHON:
1549 if (!agent_tracing_is_enabled()) {
1550 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1551 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1552 goto error;
1553 }
1554 break;
1555 default:
1556 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1557 goto error;
1558 }
1559
1560 switch (domain->type) {
1561 case LTTNG_DOMAIN_KERNEL:
1562 {
1563 struct ltt_kernel_channel *kchan;
1564
1565 kchan = trace_kernel_get_channel_by_name(attr.name,
1566 session->kernel_session);
1567 if (kchan == NULL) {
1568 if (session->snapshot.nb_output > 0 ||
1569 session->snapshot_mode) {
1570 /* Enforce mmap output for snapshot sessions. */
1571 attr.attr.output = LTTNG_EVENT_MMAP;
1572 }
1573 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1574 if (attr.name[0] != '\0') {
1575 session->kernel_session->has_non_default_channel = 1;
1576 }
1577 } else {
1578 ret = channel_kernel_enable(session->kernel_session, kchan);
1579 }
1580
1581 if (ret != LTTNG_OK) {
1582 goto error;
1583 }
1584
1585 kernel_wait_quiescent();
1586 break;
1587 }
1588 case LTTNG_DOMAIN_UST:
1589 case LTTNG_DOMAIN_JUL:
1590 case LTTNG_DOMAIN_LOG4J:
1591 case LTTNG_DOMAIN_PYTHON:
1592 {
1593 struct ltt_ust_channel *uchan;
1594
1595 /*
1596 * FIXME
1597 *
1598 * Current agent implementation limitations force us to allow
1599 * only one channel at once in "agent" subdomains. Each
1600 * subdomain has a default channel name which must be strictly
1601 * adhered to.
1602 */
1603 if (domain->type == LTTNG_DOMAIN_JUL) {
1604 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1605 LTTNG_SYMBOL_NAME_LEN)) {
1606 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1607 goto error;
1608 }
1609 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1610 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1611 LTTNG_SYMBOL_NAME_LEN)) {
1612 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1613 goto error;
1614 }
1615 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1616 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1617 LTTNG_SYMBOL_NAME_LEN)) {
1618 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1619 goto error;
1620 }
1621 }
1622
1623 chan_ht = usess->domain_global.channels;
1624
1625 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1626 if (uchan == NULL) {
1627 ret = channel_ust_create(usess, &attr, domain->buf_type);
1628 if (attr.name[0] != '\0') {
1629 usess->has_non_default_channel = 1;
1630 }
1631 } else {
1632 ret = channel_ust_enable(usess, uchan);
1633 }
1634 break;
1635 }
1636 default:
1637 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1638 goto error;
1639 }
1640
1641 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1642 session->has_non_mmap_channel = true;
1643 }
1644 error:
1645 rcu_read_unlock();
1646 end:
1647 return ret;
1648 }
1649
1650 /*
1651 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1652 */
1653 int cmd_disable_event(struct ltt_session *session,
1654 enum lttng_domain_type domain, const char *channel_name,
1655 const struct lttng_event *event)
1656 {
1657 int ret;
1658 const char *event_name;
1659
1660 DBG("Disable event command for event \'%s\'", event->name);
1661
1662 event_name = event->name;
1663
1664 /* Error out on unhandled search criteria */
1665 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1666 || event->pid || event->filter || event->exclusion) {
1667 ret = LTTNG_ERR_UNK;
1668 goto error;
1669 }
1670
1671 rcu_read_lock();
1672
1673 switch (domain) {
1674 case LTTNG_DOMAIN_KERNEL:
1675 {
1676 struct ltt_kernel_channel *kchan;
1677 struct ltt_kernel_session *ksess;
1678
1679 ksess = session->kernel_session;
1680
1681 /*
1682 * If a non-default channel has been created in the
1683 * session, explicitely require that -c chan_name needs
1684 * to be provided.
1685 */
1686 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1687 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1688 goto error_unlock;
1689 }
1690
1691 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1692 if (kchan == NULL) {
1693 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1694 goto error_unlock;
1695 }
1696
1697 switch (event->type) {
1698 case LTTNG_EVENT_ALL:
1699 case LTTNG_EVENT_TRACEPOINT:
1700 case LTTNG_EVENT_SYSCALL:
1701 case LTTNG_EVENT_PROBE:
1702 case LTTNG_EVENT_FUNCTION:
1703 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1704 if (event_name[0] == '\0') {
1705 ret = event_kernel_disable_event(kchan,
1706 NULL, event->type);
1707 } else {
1708 ret = event_kernel_disable_event(kchan,
1709 event_name, event->type);
1710 }
1711 if (ret != LTTNG_OK) {
1712 goto error_unlock;
1713 }
1714 break;
1715 default:
1716 ret = LTTNG_ERR_UNK;
1717 goto error_unlock;
1718 }
1719
1720 kernel_wait_quiescent();
1721 break;
1722 }
1723 case LTTNG_DOMAIN_UST:
1724 {
1725 struct ltt_ust_channel *uchan;
1726 struct ltt_ust_session *usess;
1727
1728 usess = session->ust_session;
1729
1730 if (validate_ust_event_name(event_name)) {
1731 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1732 goto error_unlock;
1733 }
1734
1735 /*
1736 * If a non-default channel has been created in the
1737 * session, explicitly require that -c chan_name needs
1738 * to be provided.
1739 */
1740 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1741 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1742 goto error_unlock;
1743 }
1744
1745 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1746 channel_name);
1747 if (uchan == NULL) {
1748 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1749 goto error_unlock;
1750 }
1751
1752 switch (event->type) {
1753 case LTTNG_EVENT_ALL:
1754 /*
1755 * An empty event name means that everything
1756 * should be disabled.
1757 */
1758 if (event->name[0] == '\0') {
1759 ret = event_ust_disable_all_tracepoints(usess, uchan);
1760 } else {
1761 ret = event_ust_disable_tracepoint(usess, uchan,
1762 event_name);
1763 }
1764 if (ret != LTTNG_OK) {
1765 goto error_unlock;
1766 }
1767 break;
1768 default:
1769 ret = LTTNG_ERR_UNK;
1770 goto error_unlock;
1771 }
1772
1773 DBG3("Disable UST event %s in channel %s completed", event_name,
1774 channel_name);
1775 break;
1776 }
1777 case LTTNG_DOMAIN_LOG4J:
1778 case LTTNG_DOMAIN_JUL:
1779 case LTTNG_DOMAIN_PYTHON:
1780 {
1781 struct agent *agt;
1782 struct ltt_ust_session *usess = session->ust_session;
1783
1784 assert(usess);
1785
1786 switch (event->type) {
1787 case LTTNG_EVENT_ALL:
1788 break;
1789 default:
1790 ret = LTTNG_ERR_UNK;
1791 goto error_unlock;
1792 }
1793
1794 agt = trace_ust_find_agent(usess, domain);
1795 if (!agt) {
1796 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1797 goto error_unlock;
1798 }
1799 /*
1800 * An empty event name means that everything
1801 * should be disabled.
1802 */
1803 if (event->name[0] == '\0') {
1804 ret = event_agent_disable_all(usess, agt);
1805 } else {
1806 ret = event_agent_disable(usess, agt, event_name);
1807 }
1808 if (ret != LTTNG_OK) {
1809 goto error_unlock;
1810 }
1811
1812 break;
1813 }
1814 default:
1815 ret = LTTNG_ERR_UND;
1816 goto error_unlock;
1817 }
1818
1819 ret = LTTNG_OK;
1820
1821 error_unlock:
1822 rcu_read_unlock();
1823 error:
1824 return ret;
1825 }
1826
1827 /*
1828 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1829 */
1830 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1831 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1832 {
1833 int ret, chan_kern_created = 0, chan_ust_created = 0;
1834 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1835
1836 /*
1837 * Don't try to add a context if the session has been started at
1838 * some point in time before. The tracer does not allow it and would
1839 * result in a corrupted trace.
1840 */
1841 if (session->has_been_started) {
1842 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1843 goto end;
1844 }
1845
1846 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1847 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1848 app_ctx_name = ctx->u.app_ctx.ctx_name;
1849 }
1850
1851 switch (domain) {
1852 case LTTNG_DOMAIN_KERNEL:
1853 assert(session->kernel_session);
1854
1855 if (session->kernel_session->channel_count == 0) {
1856 /* Create default channel */
1857 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1858 if (ret != LTTNG_OK) {
1859 goto error;
1860 }
1861 chan_kern_created = 1;
1862 }
1863 /* Add kernel context to kernel tracer */
1864 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1865 if (ret != LTTNG_OK) {
1866 goto error;
1867 }
1868 break;
1869 case LTTNG_DOMAIN_JUL:
1870 case LTTNG_DOMAIN_LOG4J:
1871 {
1872 /*
1873 * Validate channel name.
1874 * If no channel name is given and the domain is JUL or LOG4J,
1875 * set it to the appropriate domain-specific channel name. If
1876 * a name is provided but does not match the expexted channel
1877 * name, return an error.
1878 */
1879 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1880 strcmp(channel_name,
1881 DEFAULT_JUL_CHANNEL_NAME)) {
1882 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1883 goto error;
1884 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1885 strcmp(channel_name,
1886 DEFAULT_LOG4J_CHANNEL_NAME)) {
1887 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1888 goto error;
1889 }
1890 /* break is _not_ missing here. */
1891 }
1892 case LTTNG_DOMAIN_UST:
1893 {
1894 struct ltt_ust_session *usess = session->ust_session;
1895 unsigned int chan_count;
1896
1897 assert(usess);
1898
1899 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1900 if (chan_count == 0) {
1901 struct lttng_channel *attr;
1902 /* Create default channel */
1903 attr = channel_new_default_attr(domain, usess->buffer_type);
1904 if (attr == NULL) {
1905 ret = LTTNG_ERR_FATAL;
1906 goto error;
1907 }
1908
1909 ret = channel_ust_create(usess, attr, usess->buffer_type);
1910 if (ret != LTTNG_OK) {
1911 free(attr);
1912 goto error;
1913 }
1914 channel_attr_destroy(attr);
1915 chan_ust_created = 1;
1916 }
1917
1918 ret = context_ust_add(usess, domain, ctx, channel_name);
1919 free(app_ctx_provider_name);
1920 free(app_ctx_name);
1921 app_ctx_name = NULL;
1922 app_ctx_provider_name = NULL;
1923 if (ret != LTTNG_OK) {
1924 goto error;
1925 }
1926 break;
1927 }
1928 default:
1929 ret = LTTNG_ERR_UND;
1930 goto error;
1931 }
1932
1933 ret = LTTNG_OK;
1934 goto end;
1935
1936 error:
1937 if (chan_kern_created) {
1938 struct ltt_kernel_channel *kchan =
1939 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1940 session->kernel_session);
1941 /* Created previously, this should NOT fail. */
1942 assert(kchan);
1943 kernel_destroy_channel(kchan);
1944 }
1945
1946 if (chan_ust_created) {
1947 struct ltt_ust_channel *uchan =
1948 trace_ust_find_channel_by_name(
1949 session->ust_session->domain_global.channels,
1950 DEFAULT_CHANNEL_NAME);
1951 /* Created previously, this should NOT fail. */
1952 assert(uchan);
1953 /* Remove from the channel list of the session. */
1954 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1955 uchan);
1956 trace_ust_destroy_channel(uchan);
1957 }
1958 end:
1959 free(app_ctx_provider_name);
1960 free(app_ctx_name);
1961 return ret;
1962 }
1963
1964 static inline bool name_starts_with(const char *name, const char *prefix)
1965 {
1966 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1967
1968 return !strncmp(name, prefix, max_cmp_len);
1969 }
1970
1971 /* Perform userspace-specific event name validation */
1972 static int validate_ust_event_name(const char *name)
1973 {
1974 int ret = 0;
1975
1976 if (!name) {
1977 ret = -1;
1978 goto end;
1979 }
1980
1981 /*
1982 * Check name against all internal UST event component namespaces used
1983 * by the agents.
1984 */
1985 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1986 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1987 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1988 ret = -1;
1989 }
1990
1991 end:
1992 return ret;
1993 }
1994
1995 /*
1996 * Internal version of cmd_enable_event() with a supplemental
1997 * "internal_event" flag which is used to enable internal events which should
1998 * be hidden from clients. Such events are used in the agent implementation to
1999 * enable the events through which all "agent" events are funeled.
2000 */
2001 static int _cmd_enable_event(struct ltt_session *session,
2002 const struct lttng_domain *domain,
2003 char *channel_name, struct lttng_event *event,
2004 char *filter_expression,
2005 struct lttng_filter_bytecode *filter,
2006 struct lttng_event_exclusion *exclusion,
2007 int wpipe, bool internal_event)
2008 {
2009 int ret = 0, channel_created = 0;
2010 struct lttng_channel *attr = NULL;
2011
2012 assert(session);
2013 assert(event);
2014 assert(channel_name);
2015
2016 /* If we have a filter, we must have its filter expression */
2017 assert(!(!!filter_expression ^ !!filter));
2018
2019 /* Normalize event name as a globbing pattern */
2020 strutils_normalize_star_glob_pattern(event->name);
2021
2022 /* Normalize exclusion names as globbing patterns */
2023 if (exclusion) {
2024 size_t i;
2025
2026 for (i = 0; i < exclusion->count; i++) {
2027 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2028
2029 strutils_normalize_star_glob_pattern(name);
2030 }
2031 }
2032
2033 DBG("Enable event command for event \'%s\'", event->name);
2034
2035 rcu_read_lock();
2036
2037 switch (domain->type) {
2038 case LTTNG_DOMAIN_KERNEL:
2039 {
2040 struct ltt_kernel_channel *kchan;
2041
2042 /*
2043 * If a non-default channel has been created in the
2044 * session, explicitely require that -c chan_name needs
2045 * to be provided.
2046 */
2047 if (session->kernel_session->has_non_default_channel
2048 && channel_name[0] == '\0') {
2049 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2050 goto error;
2051 }
2052
2053 kchan = trace_kernel_get_channel_by_name(channel_name,
2054 session->kernel_session);
2055 if (kchan == NULL) {
2056 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2057 LTTNG_BUFFER_GLOBAL);
2058 if (attr == NULL) {
2059 ret = LTTNG_ERR_FATAL;
2060 goto error;
2061 }
2062 if (lttng_strncpy(attr->name, channel_name,
2063 sizeof(attr->name))) {
2064 ret = LTTNG_ERR_INVALID;
2065 goto error;
2066 }
2067
2068 ret = cmd_enable_channel(session, domain, attr, wpipe);
2069 if (ret != LTTNG_OK) {
2070 goto error;
2071 }
2072 channel_created = 1;
2073 }
2074
2075 /* Get the newly created kernel channel pointer */
2076 kchan = trace_kernel_get_channel_by_name(channel_name,
2077 session->kernel_session);
2078 if (kchan == NULL) {
2079 /* This sould not happen... */
2080 ret = LTTNG_ERR_FATAL;
2081 goto error;
2082 }
2083
2084 switch (event->type) {
2085 case LTTNG_EVENT_ALL:
2086 {
2087 char *filter_expression_a = NULL;
2088 struct lttng_filter_bytecode *filter_a = NULL;
2089
2090 /*
2091 * We need to duplicate filter_expression and filter,
2092 * because ownership is passed to first enable
2093 * event.
2094 */
2095 if (filter_expression) {
2096 filter_expression_a = strdup(filter_expression);
2097 if (!filter_expression_a) {
2098 ret = LTTNG_ERR_FATAL;
2099 goto error;
2100 }
2101 }
2102 if (filter) {
2103 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2104 if (!filter_a) {
2105 free(filter_expression_a);
2106 ret = LTTNG_ERR_FATAL;
2107 goto error;
2108 }
2109 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2110 }
2111 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2112 ret = event_kernel_enable_event(kchan, event,
2113 filter_expression, filter);
2114 /* We have passed ownership */
2115 filter_expression = NULL;
2116 filter = NULL;
2117 if (ret != LTTNG_OK) {
2118 if (channel_created) {
2119 /* Let's not leak a useless channel. */
2120 kernel_destroy_channel(kchan);
2121 }
2122 free(filter_expression_a);
2123 free(filter_a);
2124 goto error;
2125 }
2126 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2127 ret = event_kernel_enable_event(kchan, event,
2128 filter_expression_a, filter_a);
2129 /* We have passed ownership */
2130 filter_expression_a = NULL;
2131 filter_a = NULL;
2132 if (ret != LTTNG_OK) {
2133 goto error;
2134 }
2135 break;
2136 }
2137 case LTTNG_EVENT_PROBE:
2138 case LTTNG_EVENT_USERSPACE_PROBE:
2139 case LTTNG_EVENT_FUNCTION:
2140 case LTTNG_EVENT_FUNCTION_ENTRY:
2141 case LTTNG_EVENT_TRACEPOINT:
2142 ret = event_kernel_enable_event(kchan, event,
2143 filter_expression, filter);
2144 /* We have passed ownership */
2145 filter_expression = NULL;
2146 filter = NULL;
2147 if (ret != LTTNG_OK) {
2148 if (channel_created) {
2149 /* Let's not leak a useless channel. */
2150 kernel_destroy_channel(kchan);
2151 }
2152 goto error;
2153 }
2154 break;
2155 case LTTNG_EVENT_SYSCALL:
2156 ret = event_kernel_enable_event(kchan, event,
2157 filter_expression, filter);
2158 /* We have passed ownership */
2159 filter_expression = NULL;
2160 filter = NULL;
2161 if (ret != LTTNG_OK) {
2162 goto error;
2163 }
2164 break;
2165 default:
2166 ret = LTTNG_ERR_UNK;
2167 goto error;
2168 }
2169
2170 kernel_wait_quiescent();
2171 break;
2172 }
2173 case LTTNG_DOMAIN_UST:
2174 {
2175 struct ltt_ust_channel *uchan;
2176 struct ltt_ust_session *usess = session->ust_session;
2177
2178 assert(usess);
2179
2180 /*
2181 * If a non-default channel has been created in the
2182 * session, explicitely require that -c chan_name needs
2183 * to be provided.
2184 */
2185 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2186 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2187 goto error;
2188 }
2189
2190 /* Get channel from global UST domain */
2191 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2192 channel_name);
2193 if (uchan == NULL) {
2194 /* Create default channel */
2195 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2196 usess->buffer_type);
2197 if (attr == NULL) {
2198 ret = LTTNG_ERR_FATAL;
2199 goto error;
2200 }
2201 if (lttng_strncpy(attr->name, channel_name,
2202 sizeof(attr->name))) {
2203 ret = LTTNG_ERR_INVALID;
2204 goto error;
2205 }
2206
2207 ret = cmd_enable_channel(session, domain, attr, wpipe);
2208 if (ret != LTTNG_OK) {
2209 goto error;
2210 }
2211
2212 /* Get the newly created channel reference back */
2213 uchan = trace_ust_find_channel_by_name(
2214 usess->domain_global.channels, channel_name);
2215 assert(uchan);
2216 }
2217
2218 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2219 /*
2220 * Don't allow users to add UST events to channels which
2221 * are assigned to a userspace subdomain (JUL, Log4J,
2222 * Python, etc.).
2223 */
2224 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2225 goto error;
2226 }
2227
2228 if (!internal_event) {
2229 /*
2230 * Ensure the event name is not reserved for internal
2231 * use.
2232 */
2233 ret = validate_ust_event_name(event->name);
2234 if (ret) {
2235 WARN("Userspace event name %s failed validation.",
2236 event->name);
2237 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2238 goto error;
2239 }
2240 }
2241
2242 /* At this point, the session and channel exist on the tracer */
2243 ret = event_ust_enable_tracepoint(usess, uchan, event,
2244 filter_expression, filter, exclusion,
2245 internal_event);
2246 /* We have passed ownership */
2247 filter_expression = NULL;
2248 filter = NULL;
2249 exclusion = NULL;
2250 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2251 goto already_enabled;
2252 } else if (ret != LTTNG_OK) {
2253 goto error;
2254 }
2255 break;
2256 }
2257 case LTTNG_DOMAIN_LOG4J:
2258 case LTTNG_DOMAIN_JUL:
2259 case LTTNG_DOMAIN_PYTHON:
2260 {
2261 const char *default_event_name, *default_chan_name;
2262 struct agent *agt;
2263 struct lttng_event uevent;
2264 struct lttng_domain tmp_dom;
2265 struct ltt_ust_session *usess = session->ust_session;
2266
2267 assert(usess);
2268
2269 if (!agent_tracing_is_enabled()) {
2270 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2271 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2272 goto error;
2273 }
2274
2275 agt = trace_ust_find_agent(usess, domain->type);
2276 if (!agt) {
2277 agt = agent_create(domain->type);
2278 if (!agt) {
2279 ret = LTTNG_ERR_NOMEM;
2280 goto error;
2281 }
2282 agent_add(agt, usess->agents);
2283 }
2284
2285 /* Create the default tracepoint. */
2286 memset(&uevent, 0, sizeof(uevent));
2287 uevent.type = LTTNG_EVENT_TRACEPOINT;
2288 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2289 default_event_name = event_get_default_agent_ust_name(
2290 domain->type);
2291 if (!default_event_name) {
2292 ret = LTTNG_ERR_FATAL;
2293 goto error;
2294 }
2295 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2296 uevent.name[sizeof(uevent.name) - 1] = '\0';
2297
2298 /*
2299 * The domain type is changed because we are about to enable the
2300 * default channel and event for the JUL domain that are hardcoded.
2301 * This happens in the UST domain.
2302 */
2303 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2304 tmp_dom.type = LTTNG_DOMAIN_UST;
2305
2306 switch (domain->type) {
2307 case LTTNG_DOMAIN_LOG4J:
2308 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2309 break;
2310 case LTTNG_DOMAIN_JUL:
2311 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2312 break;
2313 case LTTNG_DOMAIN_PYTHON:
2314 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2315 break;
2316 default:
2317 /* The switch/case we are in makes this impossible */
2318 assert(0);
2319 }
2320
2321 {
2322 char *filter_expression_copy = NULL;
2323 struct lttng_filter_bytecode *filter_copy = NULL;
2324
2325 if (filter) {
2326 const size_t filter_size = sizeof(
2327 struct lttng_filter_bytecode)
2328 + filter->len;
2329
2330 filter_copy = zmalloc(filter_size);
2331 if (!filter_copy) {
2332 ret = LTTNG_ERR_NOMEM;
2333 goto error;
2334 }
2335 memcpy(filter_copy, filter, filter_size);
2336
2337 filter_expression_copy =
2338 strdup(filter_expression);
2339 if (!filter_expression) {
2340 ret = LTTNG_ERR_NOMEM;
2341 }
2342
2343 if (!filter_expression_copy || !filter_copy) {
2344 free(filter_expression_copy);
2345 free(filter_copy);
2346 goto error;
2347 }
2348 }
2349
2350 ret = cmd_enable_event_internal(session, &tmp_dom,
2351 (char *) default_chan_name,
2352 &uevent, filter_expression_copy,
2353 filter_copy, NULL, wpipe);
2354 }
2355
2356 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2357 goto already_enabled;
2358 } else if (ret != LTTNG_OK) {
2359 goto error;
2360 }
2361
2362 /* The wild card * means that everything should be enabled. */
2363 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2364 ret = event_agent_enable_all(usess, agt, event, filter,
2365 filter_expression);
2366 } else {
2367 ret = event_agent_enable(usess, agt, event, filter,
2368 filter_expression);
2369 }
2370 filter = NULL;
2371 filter_expression = NULL;
2372 if (ret != LTTNG_OK) {
2373 goto error;
2374 }
2375
2376 break;
2377 }
2378 default:
2379 ret = LTTNG_ERR_UND;
2380 goto error;
2381 }
2382
2383 ret = LTTNG_OK;
2384
2385 already_enabled:
2386 error:
2387 free(filter_expression);
2388 free(filter);
2389 free(exclusion);
2390 channel_attr_destroy(attr);
2391 rcu_read_unlock();
2392 return ret;
2393 }
2394
2395 /*
2396 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2397 * We own filter, exclusion, and filter_expression.
2398 */
2399 int cmd_enable_event(struct ltt_session *session,
2400 const struct lttng_domain *domain,
2401 char *channel_name, struct lttng_event *event,
2402 char *filter_expression,
2403 struct lttng_filter_bytecode *filter,
2404 struct lttng_event_exclusion *exclusion,
2405 int wpipe)
2406 {
2407 return _cmd_enable_event(session, domain, channel_name, event,
2408 filter_expression, filter, exclusion, wpipe, false);
2409 }
2410
2411 /*
2412 * Enable an event which is internal to LTTng. An internal should
2413 * never be made visible to clients and are immune to checks such as
2414 * reserved names.
2415 */
2416 static int cmd_enable_event_internal(struct ltt_session *session,
2417 const struct lttng_domain *domain,
2418 char *channel_name, struct lttng_event *event,
2419 char *filter_expression,
2420 struct lttng_filter_bytecode *filter,
2421 struct lttng_event_exclusion *exclusion,
2422 int wpipe)
2423 {
2424 return _cmd_enable_event(session, domain, channel_name, event,
2425 filter_expression, filter, exclusion, wpipe, true);
2426 }
2427
2428 /*
2429 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2430 */
2431 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2432 struct lttng_event **events)
2433 {
2434 int ret;
2435 ssize_t nb_events = 0;
2436
2437 switch (domain) {
2438 case LTTNG_DOMAIN_KERNEL:
2439 nb_events = kernel_list_events(events);
2440 if (nb_events < 0) {
2441 ret = LTTNG_ERR_KERN_LIST_FAIL;
2442 goto error;
2443 }
2444 break;
2445 case LTTNG_DOMAIN_UST:
2446 nb_events = ust_app_list_events(events);
2447 if (nb_events < 0) {
2448 ret = LTTNG_ERR_UST_LIST_FAIL;
2449 goto error;
2450 }
2451 break;
2452 case LTTNG_DOMAIN_LOG4J:
2453 case LTTNG_DOMAIN_JUL:
2454 case LTTNG_DOMAIN_PYTHON:
2455 nb_events = agent_list_events(events, domain);
2456 if (nb_events < 0) {
2457 ret = LTTNG_ERR_UST_LIST_FAIL;
2458 goto error;
2459 }
2460 break;
2461 default:
2462 ret = LTTNG_ERR_UND;
2463 goto error;
2464 }
2465
2466 return nb_events;
2467
2468 error:
2469 /* Return negative value to differentiate return code */
2470 return -ret;
2471 }
2472
2473 /*
2474 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2475 */
2476 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2477 struct lttng_event_field **fields)
2478 {
2479 int ret;
2480 ssize_t nb_fields = 0;
2481
2482 switch (domain) {
2483 case LTTNG_DOMAIN_UST:
2484 nb_fields = ust_app_list_event_fields(fields);
2485 if (nb_fields < 0) {
2486 ret = LTTNG_ERR_UST_LIST_FAIL;
2487 goto error;
2488 }
2489 break;
2490 case LTTNG_DOMAIN_KERNEL:
2491 default: /* fall-through */
2492 ret = LTTNG_ERR_UND;
2493 goto error;
2494 }
2495
2496 return nb_fields;
2497
2498 error:
2499 /* Return negative value to differentiate return code */
2500 return -ret;
2501 }
2502
2503 ssize_t cmd_list_syscalls(struct lttng_event **events)
2504 {
2505 return syscall_table_list(events);
2506 }
2507
2508 /*
2509 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2510 *
2511 * Called with session lock held.
2512 */
2513 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2514 enum lttng_domain_type domain, int32_t **pids)
2515 {
2516 int ret;
2517 ssize_t nr_pids = 0;
2518
2519 switch (domain) {
2520 case LTTNG_DOMAIN_KERNEL:
2521 {
2522 struct ltt_kernel_session *ksess;
2523
2524 ksess = session->kernel_session;
2525 nr_pids = kernel_list_tracker_pids(ksess, pids);
2526 if (nr_pids < 0) {
2527 ret = LTTNG_ERR_KERN_LIST_FAIL;
2528 goto error;
2529 }
2530 break;
2531 }
2532 case LTTNG_DOMAIN_UST:
2533 {
2534 struct ltt_ust_session *usess;
2535
2536 usess = session->ust_session;
2537 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2538 if (nr_pids < 0) {
2539 ret = LTTNG_ERR_UST_LIST_FAIL;
2540 goto error;
2541 }
2542 break;
2543 }
2544 case LTTNG_DOMAIN_LOG4J:
2545 case LTTNG_DOMAIN_JUL:
2546 case LTTNG_DOMAIN_PYTHON:
2547 default:
2548 ret = LTTNG_ERR_UND;
2549 goto error;
2550 }
2551
2552 return nr_pids;
2553
2554 error:
2555 /* Return negative value to differentiate return code */
2556 return -ret;
2557 }
2558
2559 /*
2560 * Command LTTNG_START_TRACE processed by the client thread.
2561 *
2562 * Called with session mutex held.
2563 */
2564 int cmd_start_trace(struct ltt_session *session)
2565 {
2566 enum lttng_error_code ret;
2567 unsigned long nb_chan = 0;
2568 struct ltt_kernel_session *ksession;
2569 struct ltt_ust_session *usess;
2570
2571 assert(session);
2572
2573 /* Ease our life a bit ;) */
2574 ksession = session->kernel_session;
2575 usess = session->ust_session;
2576
2577 /* Is the session already started? */
2578 if (session->active) {
2579 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2580 goto error;
2581 }
2582
2583 /*
2584 * Starting a session without channel is useless since after that it's not
2585 * possible to enable channel thus inform the client.
2586 */
2587 if (usess && usess->domain_global.channels) {
2588 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2589 }
2590 if (ksession) {
2591 nb_chan += ksession->channel_count;
2592 }
2593 if (!nb_chan) {
2594 ret = LTTNG_ERR_NO_CHANNEL;
2595 goto error;
2596 }
2597
2598 if (session->output_traces && !session->current_trace_chunk) {
2599 struct lttng_trace_chunk *trace_chunk;
2600
2601 trace_chunk = session_create_new_trace_chunk(
2602 session, NULL, NULL, NULL);
2603 if (!trace_chunk) {
2604 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2605 goto error;
2606 }
2607 assert(!session->current_trace_chunk);
2608 ret = session_set_trace_chunk(session, trace_chunk, NULL);
2609 lttng_trace_chunk_put(trace_chunk);
2610 if (ret) {
2611 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2612 goto error;
2613 }
2614 }
2615
2616 /* Kernel tracing */
2617 if (ksession != NULL) {
2618 DBG("Start kernel tracing session %s", session->name);
2619 ret = start_kernel_session(ksession);
2620 if (ret != LTTNG_OK) {
2621 goto error;
2622 }
2623 }
2624
2625 /* Flag session that trace should start automatically */
2626 if (usess) {
2627 int int_ret = ust_app_start_trace_all(usess);
2628
2629 if (int_ret < 0) {
2630 ret = LTTNG_ERR_UST_START_FAIL;
2631 goto error;
2632 }
2633 }
2634
2635 /* Flag this after a successful start. */
2636 session->has_been_started = 1;
2637 session->active = 1;
2638
2639 /*
2640 * Clear the flag that indicates that a rotation was done while the
2641 * session was stopped.
2642 */
2643 session->rotated_after_last_stop = false;
2644
2645 if (session->rotate_timer_period) {
2646 int int_ret = timer_session_rotation_schedule_timer_start(
2647 session, session->rotate_timer_period);
2648
2649 if (int_ret < 0) {
2650 ERR("Failed to enable rotate timer");
2651 ret = LTTNG_ERR_UNK;
2652 goto error;
2653 }
2654 }
2655
2656 ret = LTTNG_OK;
2657
2658 error:
2659 return ret;
2660 }
2661
2662 /*
2663 * Command LTTNG_STOP_TRACE processed by the client thread.
2664 */
2665 int cmd_stop_trace(struct ltt_session *session)
2666 {
2667 int ret;
2668 struct ltt_kernel_channel *kchan;
2669 struct ltt_kernel_session *ksession;
2670 struct ltt_ust_session *usess;
2671 bool error_occurred = false;
2672
2673 assert(session);
2674
2675 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2676 /* Short cut */
2677 ksession = session->kernel_session;
2678 usess = session->ust_session;
2679
2680 /* Session is not active. Skip everythong and inform the client. */
2681 if (!session->active) {
2682 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2683 goto error;
2684 }
2685
2686 /* Kernel tracer */
2687 if (ksession && ksession->active) {
2688 DBG("Stop kernel tracing");
2689
2690 ret = kernel_stop_session(ksession);
2691 if (ret < 0) {
2692 ret = LTTNG_ERR_KERN_STOP_FAIL;
2693 goto error;
2694 }
2695
2696 kernel_wait_quiescent();
2697
2698 /* Flush metadata after stopping (if exists) */
2699 if (ksession->metadata_stream_fd >= 0) {
2700 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2701 if (ret < 0) {
2702 ERR("Kernel metadata flush failed");
2703 error_occurred = true;
2704 }
2705 }
2706
2707 /* Flush all buffers after stopping */
2708 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2709 ret = kernel_flush_buffer(kchan);
2710 if (ret < 0) {
2711 ERR("Kernel flush buffer error");
2712 error_occurred = true;
2713 }
2714 }
2715
2716 ksession->active = 0;
2717 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2718 session->id);
2719 }
2720
2721 if (usess && usess->active) {
2722 ret = ust_app_stop_trace_all(usess);
2723 if (ret < 0) {
2724 ret = LTTNG_ERR_UST_STOP_FAIL;
2725 goto error;
2726 }
2727 }
2728
2729 /* Flag inactive after a successful stop. */
2730 session->active = 0;
2731 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2732
2733 error:
2734 return ret;
2735 }
2736
2737 /*
2738 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2739 */
2740 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2741 struct lttng_uri *uris)
2742 {
2743 int ret, i;
2744 struct ltt_kernel_session *ksess = session->kernel_session;
2745 struct ltt_ust_session *usess = session->ust_session;
2746
2747 assert(session);
2748 assert(uris);
2749 assert(nb_uri > 0);
2750
2751 /* Can't set consumer URI if the session is active. */
2752 if (session->active) {
2753 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2754 goto error;
2755 }
2756
2757 /* Set the "global" consumer URIs */
2758 for (i = 0; i < nb_uri; i++) {
2759 ret = add_uri_to_consumer(session,
2760 session->consumer,
2761 &uris[i], LTTNG_DOMAIN_NONE);
2762 if (ret != LTTNG_OK) {
2763 goto error;
2764 }
2765 }
2766
2767 /* Set UST session URIs */
2768 if (session->ust_session) {
2769 for (i = 0; i < nb_uri; i++) {
2770 ret = add_uri_to_consumer(session,
2771 session->ust_session->consumer,
2772 &uris[i], LTTNG_DOMAIN_UST);
2773 if (ret != LTTNG_OK) {
2774 goto error;
2775 }
2776 }
2777 }
2778
2779 /* Set kernel session URIs */
2780 if (session->kernel_session) {
2781 for (i = 0; i < nb_uri; i++) {
2782 ret = add_uri_to_consumer(session,
2783 session->kernel_session->consumer,
2784 &uris[i], LTTNG_DOMAIN_KERNEL);
2785 if (ret != LTTNG_OK) {
2786 goto error;
2787 }
2788 }
2789 }
2790
2791 /*
2792 * Make sure to set the session in output mode after we set URI since a
2793 * session can be created without URL (thus flagged in no output mode).
2794 */
2795 session->output_traces = 1;
2796 if (ksess) {
2797 ksess->output_traces = 1;
2798 }
2799
2800 if (usess) {
2801 usess->output_traces = 1;
2802 }
2803
2804 /* All good! */
2805 ret = LTTNG_OK;
2806
2807 error:
2808 return ret;
2809 }
2810
2811 static
2812 enum lttng_error_code set_session_output_from_descriptor(
2813 struct ltt_session *session,
2814 const struct lttng_session_descriptor *descriptor)
2815 {
2816 int ret;
2817 enum lttng_error_code ret_code = LTTNG_OK;
2818 enum lttng_session_descriptor_type session_type =
2819 lttng_session_descriptor_get_type(descriptor);
2820 enum lttng_session_descriptor_output_type output_type =
2821 lttng_session_descriptor_get_output_type(descriptor);
2822 struct lttng_uri uris[2] = {};
2823 size_t uri_count = 0;
2824
2825 switch (output_type) {
2826 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2827 goto end;
2828 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2829 lttng_session_descriptor_get_local_output_uri(descriptor,
2830 &uris[0]);
2831 uri_count = 1;
2832 break;
2833 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2834 lttng_session_descriptor_get_network_output_uris(descriptor,
2835 &uris[0], &uris[1]);
2836 uri_count = 2;
2837 break;
2838 default:
2839 ret_code = LTTNG_ERR_INVALID;
2840 goto end;
2841 }
2842
2843 switch (session_type) {
2844 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2845 {
2846 struct snapshot_output *new_output = NULL;
2847
2848 new_output = snapshot_output_alloc();
2849 if (!new_output) {
2850 ret_code = LTTNG_ERR_NOMEM;
2851 goto end;
2852 }
2853
2854 ret = snapshot_output_init_with_uri(session,
2855 DEFAULT_SNAPSHOT_MAX_SIZE,
2856 NULL, uris, uri_count, session->consumer,
2857 new_output, &session->snapshot);
2858 if (ret < 0) {
2859 ret_code = (ret == -ENOMEM) ?
2860 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2861 snapshot_output_destroy(new_output);
2862 goto end;
2863 }
2864 snapshot_add_output(&session->snapshot, new_output);
2865 break;
2866 }
2867 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2868 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2869 {
2870 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2871 break;
2872 }
2873 default:
2874 ret_code = LTTNG_ERR_INVALID;
2875 goto end;
2876 }
2877 end:
2878 return ret_code;
2879 }
2880
2881 static
2882 enum lttng_error_code cmd_create_session_from_descriptor(
2883 struct lttng_session_descriptor *descriptor,
2884 const lttng_sock_cred *creds,
2885 const char *home_path)
2886 {
2887 int ret;
2888 enum lttng_error_code ret_code;
2889 const char *session_name;
2890 struct ltt_session *new_session = NULL;
2891 enum lttng_session_descriptor_status descriptor_status;
2892 const char *base_path;
2893
2894 session_lock_list();
2895 if (home_path) {
2896 if (*home_path != '/') {
2897 ERR("Home path provided by client is not absolute");
2898 ret_code = LTTNG_ERR_INVALID;
2899 goto end;
2900 }
2901 }
2902
2903 descriptor_status = lttng_session_descriptor_get_session_name(
2904 descriptor, &session_name);
2905 switch (descriptor_status) {
2906 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
2907 break;
2908 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
2909 session_name = NULL;
2910 break;
2911 default:
2912 ret_code = LTTNG_ERR_INVALID;
2913 goto end;
2914 }
2915 ret = lttng_session_descriptor_get_base_path(descriptor, &base_path);
2916 if (ret) {
2917 ret_code = LTTNG_ERR_INVALID;
2918 goto end;
2919 }
2920 ret_code = session_create(session_name, creds->uid, creds->gid,
2921 base_path, &new_session);
2922 if (ret_code != LTTNG_OK) {
2923 goto end;
2924 }
2925
2926 if (!session_name) {
2927 ret = lttng_session_descriptor_set_session_name(descriptor,
2928 new_session->name);
2929 if (ret) {
2930 ret_code = LTTNG_ERR_SESSION_FAIL;
2931 goto end;
2932 }
2933 }
2934
2935 if (!lttng_session_descriptor_is_output_destination_initialized(
2936 descriptor)) {
2937 /*
2938 * Only include the session's creation time in the output
2939 * destination if the name of the session itself was
2940 * not auto-generated.
2941 */
2942 ret_code = lttng_session_descriptor_set_default_output(
2943 descriptor,
2944 session_name ? &new_session->creation_time : NULL,
2945 home_path);
2946 if (ret_code != LTTNG_OK) {
2947 goto end;
2948 }
2949 } else {
2950 new_session->has_user_specified_directory =
2951 lttng_session_descriptor_has_output_directory(
2952 descriptor);
2953 }
2954
2955 switch (lttng_session_descriptor_get_type(descriptor)) {
2956 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2957 new_session->snapshot_mode = 1;
2958 break;
2959 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2960 new_session->live_timer =
2961 lttng_session_descriptor_live_get_timer_interval(
2962 descriptor);
2963 break;
2964 default:
2965 break;
2966 }
2967
2968 ret_code = set_session_output_from_descriptor(new_session, descriptor);
2969 if (ret_code != LTTNG_OK) {
2970 goto end;
2971 }
2972 new_session->consumer->enabled = 1;
2973 ret_code = LTTNG_OK;
2974 end:
2975 /* Release reference provided by the session_create function. */
2976 session_put(new_session);
2977 if (ret_code != LTTNG_OK && new_session) {
2978 /* Release the global reference on error. */
2979 session_destroy(new_session);
2980 }
2981 session_unlock_list();
2982 return ret_code;
2983 }
2984
2985 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
2986 struct lttng_session_descriptor **return_descriptor)
2987 {
2988 int ret;
2989 size_t payload_size;
2990 struct lttng_dynamic_buffer payload;
2991 struct lttng_buffer_view home_dir_view;
2992 struct lttng_buffer_view session_descriptor_view;
2993 struct lttng_session_descriptor *session_descriptor = NULL;
2994 enum lttng_error_code ret_code;
2995
2996 lttng_dynamic_buffer_init(&payload);
2997 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
2998 LTTNG_PATH_MAX) {
2999 ret_code = LTTNG_ERR_INVALID;
3000 goto error;
3001 }
3002 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3003 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3004 ret_code = LTTNG_ERR_INVALID;
3005 goto error;
3006 }
3007
3008 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3009 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3010 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3011 if (ret) {
3012 ret_code = LTTNG_ERR_NOMEM;
3013 goto error;
3014 }
3015
3016 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3017 if (ret <= 0) {
3018 ERR("Reception of session descriptor failed, aborting.");
3019 ret_code = LTTNG_ERR_SESSION_FAIL;
3020 goto error;
3021 }
3022
3023 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3024 &payload,
3025 0,
3026 cmd_ctx->lsm->u.create_session.home_dir_size);
3027 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3028 &payload,
3029 cmd_ctx->lsm->u.create_session.home_dir_size,
3030 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3031
3032 ret = lttng_session_descriptor_create_from_buffer(
3033 &session_descriptor_view, &session_descriptor);
3034 if (ret < 0) {
3035 ERR("Failed to create session descriptor from payload of \"create session\" command");
3036 ret_code = LTTNG_ERR_INVALID;
3037 goto error;
3038 }
3039
3040 /*
3041 * Sets the descriptor's auto-generated properties (name, output) if
3042 * needed.
3043 */
3044 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3045 &cmd_ctx->creds,
3046 home_dir_view.size ? home_dir_view.data : NULL);
3047 if (ret_code != LTTNG_OK) {
3048 goto error;
3049 }
3050
3051 ret_code = LTTNG_OK;
3052 *return_descriptor = session_descriptor;
3053 session_descriptor = NULL;
3054 error:
3055 lttng_dynamic_buffer_reset(&payload);
3056 lttng_session_descriptor_destroy(session_descriptor);
3057 return ret_code;
3058 }
3059
3060 static
3061 void cmd_destroy_session_reply(const struct ltt_session *session,
3062 void *_reply_context)
3063 {
3064 int ret;
3065 ssize_t comm_ret;
3066 const struct cmd_destroy_session_reply_context *reply_context =
3067 _reply_context;
3068 struct lttng_dynamic_buffer payload;
3069 struct lttcomm_session_destroy_command_header cmd_header;
3070 struct lttng_trace_archive_location *location = NULL;
3071 struct lttcomm_lttng_msg llm = {
3072 .cmd_type = LTTNG_DESTROY_SESSION,
3073 .ret_code = LTTNG_OK,
3074 .pid = UINT32_MAX,
3075 .cmd_header_size =
3076 sizeof(struct lttcomm_session_destroy_command_header),
3077 .data_size = 0,
3078 };
3079 size_t payload_size_before_location;
3080
3081 lttng_dynamic_buffer_init(&payload);
3082
3083 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3084 if (ret) {
3085 ERR("Failed to append session destruction message");
3086 goto error;
3087 }
3088
3089 cmd_header.rotation_state =
3090 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3091 session->rotation_state :
3092 LTTNG_ROTATION_STATE_NO_ROTATION);
3093 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3094 sizeof(cmd_header));
3095 if (ret) {
3096 ERR("Failed to append session destruction command header");
3097 goto error;
3098 }
3099
3100 if (!reply_context->implicit_rotation_on_destroy) {
3101 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3102 session->name);
3103 goto send_reply;
3104 }
3105 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3106 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3107 session->name);
3108 goto send_reply;
3109 }
3110
3111 location = session_get_trace_archive_location(session);
3112 if (!location) {
3113 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3114 session->name);
3115 goto error;
3116 }
3117
3118 payload_size_before_location = payload.size;
3119 comm_ret = lttng_trace_archive_location_serialize(location,
3120 &payload);
3121 if (comm_ret < 0) {
3122 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3123 session->name);
3124 goto error;
3125 }
3126 /* Update the message to indicate the location's length. */
3127 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3128 payload.size - payload_size_before_location;
3129 send_reply:
3130 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3131 payload.data, payload.size);
3132 if (comm_ret != (ssize_t) payload.size) {
3133 ERR("Failed to send result of the destruction of session \"%s\" to client",
3134 session->name);
3135 }
3136 error:
3137 ret = close(reply_context->reply_sock_fd);
3138 if (ret) {
3139 PERROR("Failed to close client socket in deferred session destroy reply");
3140 }
3141 lttng_dynamic_buffer_reset(&payload);
3142 free(_reply_context);
3143 }
3144
3145 /*
3146 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3147 *
3148 * Called with session lock held.
3149 */
3150 int cmd_destroy_session(struct ltt_session *session,
3151 struct notification_thread_handle *notification_thread_handle,
3152 int *sock_fd)
3153 {
3154 int ret;
3155 struct cmd_destroy_session_reply_context *reply_context = NULL;
3156
3157 if (sock_fd) {
3158 reply_context = zmalloc(sizeof(*reply_context));
3159 if (!reply_context) {
3160 ret = LTTNG_ERR_NOMEM;
3161 goto end;
3162 }
3163 reply_context->reply_sock_fd = *sock_fd;
3164 }
3165
3166 /* Safety net */
3167 assert(session);
3168
3169 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3170 session->id);
3171 if (session->active) {
3172 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3173 session->name);
3174 ret = cmd_stop_trace(session);
3175 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3176 /* Carry on with the destruction of the session. */
3177 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3178 session->name, lttng_strerror(-ret));
3179 }
3180 }
3181
3182 if (session->rotation_schedule_timer_enabled) {
3183 if (timer_session_rotation_schedule_timer_stop(
3184 session)) {
3185 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3186 session->name);
3187 }
3188 }
3189
3190 if (session->rotate_size) {
3191 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3192 session->rotate_size = 0;
3193 }
3194
3195 if (session->most_recent_chunk_id.is_set &&
3196 session->most_recent_chunk_id.value != 0 &&
3197 session->current_trace_chunk && session->output_traces) {
3198 /*
3199 * Perform a last rotation on destruction if rotations have
3200 * occurred during the session's lifetime.
3201 */
3202 ret = cmd_rotate_session(session, NULL, false);
3203 if (ret != LTTNG_OK) {
3204 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3205 session->name, lttng_strerror(-ret));
3206 }
3207 if (reply_context) {
3208 reply_context->implicit_rotation_on_destroy = true;
3209 }
3210 } else if (session->has_been_started && session->current_trace_chunk) {
3211 /*
3212 * The user has not triggered a session rotation. However, to
3213 * ensure all data has been consumed, the session is rotated
3214 * to a 'null' trace chunk before it is destroyed.
3215 *
3216 * This is a "quiet" rotation meaning that no notification is
3217 * emitted and no renaming of the current trace chunk takes
3218 * place.
3219 */
3220 ret = cmd_rotate_session(session, NULL, true);
3221 if (ret != LTTNG_OK) {
3222 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3223 session->name, lttng_strerror(-ret));
3224 }
3225 }
3226
3227 if (session->shm_path[0]) {
3228 /*
3229 * When a session is created with an explicit shm_path,
3230 * the consumer daemon will create its shared memory files
3231 * at that location and will *not* unlink them. This is normal
3232 * as the intention of that feature is to make it possible
3233 * to retrieve the content of those files should a crash occur.
3234 *
3235 * To ensure the content of those files can be used, the
3236 * sessiond daemon will replicate the content of the metadata
3237 * cache in a metadata file.
3238 *
3239 * On clean-up, it is expected that the consumer daemon will
3240 * unlink the shared memory files and that the session daemon
3241 * will unlink the metadata file. Then, the session's directory
3242 * in the shm path can be removed.
3243 *
3244 * Unfortunately, a flaw in the design of the sessiond's and
3245 * consumerd's tear down of channels makes it impossible to
3246 * determine when the sessiond _and_ the consumerd have both
3247 * destroyed their representation of a channel. For one, the
3248 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3249 * callbacks in both daemons.
3250 *
3251 * However, it is also impossible for the sessiond to know when
3252 * the consumer daemon is done destroying its channel(s) since
3253 * it occurs as a reaction to the closing of the channel's file
3254 * descriptor. There is no resulting communication initiated
3255 * from the consumerd to the sessiond to confirm that the
3256 * operation is completed (and was successful).
3257 *
3258 * Until this is all fixed, the session daemon checks for the
3259 * removal of the session's shm path which makes it possible
3260 * to safely advertise a session as having been destroyed.
3261 *
3262 * Prior to this fix, it was not possible to reliably save
3263 * a session making use of the --shm-path option, destroy it,
3264 * and load it again. This is because the creation of the
3265 * session would fail upon seeing the session's shm path
3266 * already in existence.
3267 *
3268 * Note that none of the error paths in the check for the
3269 * directory's existence return an error. This is normal
3270 * as there isn't much that can be done. The session will
3271 * be destroyed properly, except that we can't offer the
3272 * guarantee that the same session can be re-created.
3273 */
3274 current_completion_handler = &destroy_completion_handler.handler;
3275 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3276 session->shm_path,
3277 sizeof(destroy_completion_handler.shm_path));
3278 assert(!ret);
3279 }
3280
3281 /*
3282 * The session is destroyed. However, note that the command context
3283 * still holds a reference to the session, thus delaying its destruction
3284 * _at least_ up to the point when that reference is released.
3285 */
3286 session_destroy(session);
3287 if (reply_context) {
3288 ret = session_add_destroy_notifier(session,
3289 cmd_destroy_session_reply,
3290 (void *) reply_context);
3291 if (ret) {
3292 ret = LTTNG_ERR_FATAL;
3293 goto end;
3294 } else {
3295 *sock_fd = -1;
3296 }
3297 }
3298 ret = LTTNG_OK;
3299 end:
3300 return ret;
3301 }
3302
3303 /*
3304 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3305 */
3306 int cmd_register_consumer(struct ltt_session *session,
3307 enum lttng_domain_type domain, const char *sock_path,
3308 struct consumer_data *cdata)
3309 {
3310 int ret, sock;
3311 struct consumer_socket *socket = NULL;
3312
3313 assert(session);
3314 assert(cdata);
3315 assert(sock_path);
3316
3317 switch (domain) {
3318 case LTTNG_DOMAIN_KERNEL:
3319 {
3320 struct ltt_kernel_session *ksess = session->kernel_session;
3321
3322 assert(ksess);
3323
3324 /* Can't register a consumer if there is already one */
3325 if (ksess->consumer_fds_sent != 0) {
3326 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3327 goto error;
3328 }
3329
3330 sock = lttcomm_connect_unix_sock(sock_path);
3331 if (sock < 0) {
3332 ret = LTTNG_ERR_CONNECT_FAIL;
3333 goto error;
3334 }
3335 cdata->cmd_sock = sock;
3336
3337 socket = consumer_allocate_socket(&cdata->cmd_sock);
3338 if (socket == NULL) {
3339 ret = close(sock);
3340 if (ret < 0) {
3341 PERROR("close register consumer");
3342 }
3343 cdata->cmd_sock = -1;
3344 ret = LTTNG_ERR_FATAL;
3345 goto error;
3346 }
3347
3348 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3349 if (socket->lock == NULL) {
3350 PERROR("zmalloc pthread mutex");
3351 ret = LTTNG_ERR_FATAL;
3352 goto error;
3353 }
3354 pthread_mutex_init(socket->lock, NULL);
3355 socket->registered = 1;
3356
3357 rcu_read_lock();
3358 consumer_add_socket(socket, ksess->consumer);
3359 rcu_read_unlock();
3360
3361 pthread_mutex_lock(&cdata->pid_mutex);
3362 cdata->pid = -1;
3363 pthread_mutex_unlock(&cdata->pid_mutex);
3364
3365 break;
3366 }
3367 default:
3368 /* TODO: Userspace tracing */
3369 ret = LTTNG_ERR_UND;
3370 goto error;
3371 }
3372
3373 return LTTNG_OK;
3374
3375 error:
3376 if (socket) {
3377 consumer_destroy_socket(socket);
3378 }
3379 return ret;
3380 }
3381
3382 /*
3383 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3384 */
3385 ssize_t cmd_list_domains(struct ltt_session *session,
3386 struct lttng_domain **domains)
3387 {
3388 int ret, index = 0;
3389 ssize_t nb_dom = 0;
3390 struct agent *agt;
3391 struct lttng_ht_iter iter;
3392
3393 if (session->kernel_session != NULL) {
3394 DBG3("Listing domains found kernel domain");
3395 nb_dom++;
3396 }
3397
3398 if (session->ust_session != NULL) {
3399 DBG3("Listing domains found UST global domain");
3400 nb_dom++;
3401
3402 rcu_read_lock();
3403 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3404 agt, node.node) {
3405 if (agt->being_used) {
3406 nb_dom++;
3407 }
3408 }
3409 rcu_read_unlock();
3410 }
3411
3412 if (!nb_dom) {
3413 goto end;
3414 }
3415
3416 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3417 if (*domains == NULL) {
3418 ret = LTTNG_ERR_FATAL;
3419 goto error;
3420 }
3421
3422 if (session->kernel_session != NULL) {
3423 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3424
3425 /* Kernel session buffer type is always GLOBAL */
3426 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3427
3428 index++;
3429 }
3430
3431 if (session->ust_session != NULL) {
3432 (*domains)[index].type = LTTNG_DOMAIN_UST;
3433 (*domains)[index].buf_type = session->ust_session->buffer_type;
3434 index++;
3435
3436 rcu_read_lock();
3437 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3438 agt, node.node) {
3439 if (agt->being_used) {
3440 (*domains)[index].type = agt->domain;
3441 (*domains)[index].buf_type = session->ust_session->buffer_type;
3442 index++;
3443 }
3444 }
3445 rcu_read_unlock();
3446 }
3447 end:
3448 return nb_dom;
3449
3450 error:
3451 /* Return negative value to differentiate return code */
3452 return -ret;
3453 }
3454
3455
3456 /*
3457 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3458 */
3459 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3460 struct ltt_session *session, struct lttng_channel **channels)
3461 {
3462 ssize_t nb_chan = 0, payload_size = 0, ret;
3463
3464 switch (domain) {
3465 case LTTNG_DOMAIN_KERNEL:
3466 if (session->kernel_session != NULL) {
3467 nb_chan = session->kernel_session->channel_count;
3468 }
3469 DBG3("Number of kernel channels %zd", nb_chan);
3470 if (nb_chan <= 0) {
3471 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3472 goto end;
3473 }
3474 break;
3475 case LTTNG_DOMAIN_UST:
3476 if (session->ust_session != NULL) {
3477 rcu_read_lock();
3478 nb_chan = lttng_ht_get_count(
3479 session->ust_session->domain_global.channels);
3480 rcu_read_unlock();
3481 }
3482 DBG3("Number of UST global channels %zd", nb_chan);
3483 if (nb_chan < 0) {
3484 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3485 goto end;
3486 }
3487 break;
3488 default:
3489 ret = -LTTNG_ERR_UND;
3490 goto end;
3491 }
3492
3493 if (nb_chan > 0) {
3494 const size_t channel_size = sizeof(struct lttng_channel) +
3495 sizeof(struct lttng_channel_extended);
3496 struct lttng_channel_extended *channel_exts;
3497
3498 payload_size = nb_chan * channel_size;
3499 *channels = zmalloc(payload_size);
3500 if (*channels == NULL) {
3501 ret = -LTTNG_ERR_FATAL;
3502 goto end;
3503 }
3504
3505 channel_exts = ((void *) *channels) +
3506 (nb_chan * sizeof(struct lttng_channel));
3507 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3508 if (ret != LTTNG_OK) {
3509 free(*channels);
3510 *channels = NULL;
3511 goto end;
3512 }
3513 } else {
3514 *channels = NULL;
3515 }
3516
3517 ret = payload_size;
3518 end:
3519 return ret;
3520 }
3521
3522 /*
3523 * Command LTTNG_LIST_EVENTS processed by the client thread.
3524 */
3525 ssize_t cmd_list_events(enum lttng_domain_type domain,
3526 struct ltt_session *session, char *channel_name,
3527 struct lttng_event **events, size_t *total_size)
3528 {
3529 int ret = 0;
3530 ssize_t nb_event = 0;
3531
3532 switch (domain) {
3533 case LTTNG_DOMAIN_KERNEL:
3534 if (session->kernel_session != NULL) {
3535 nb_event = list_lttng_kernel_events(channel_name,
3536 session->kernel_session, events,
3537 total_size);
3538 }
3539 break;
3540 case LTTNG_DOMAIN_UST:
3541 {
3542 if (session->ust_session != NULL) {
3543 nb_event = list_lttng_ust_global_events(channel_name,
3544 &session->ust_session->domain_global, events,
3545 total_size);
3546 }
3547 break;
3548 }
3549 case LTTNG_DOMAIN_LOG4J:
3550 case LTTNG_DOMAIN_JUL:
3551 case LTTNG_DOMAIN_PYTHON:
3552 if (session->ust_session) {
3553 struct lttng_ht_iter iter;
3554 struct agent *agt;
3555
3556 rcu_read_lock();
3557 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3558 &iter.iter, agt, node.node) {
3559 if (agt->domain == domain) {
3560 nb_event = list_lttng_agent_events(
3561 agt, events,
3562 total_size);
3563 break;
3564 }
3565 }
3566 rcu_read_unlock();
3567 }
3568 break;
3569 default:
3570 ret = LTTNG_ERR_UND;
3571 goto error;
3572 }
3573
3574 return nb_event;
3575
3576 error:
3577 /* Return negative value to differentiate return code */
3578 return -ret;
3579 }
3580
3581 /*
3582 * Using the session list, filled a lttng_session array to send back to the
3583 * client for session listing.
3584 *
3585 * The session list lock MUST be acquired before calling this function. Use
3586 * session_lock_list() and session_unlock_list().
3587 */
3588 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3589 size_t session_count, uid_t uid, gid_t gid)
3590 {
3591 int ret;
3592 unsigned int i = 0;
3593 struct ltt_session *session;
3594 struct ltt_session_list *list = session_get_list();
3595 struct lttng_session_extended *extended =
3596 (typeof(extended)) (&sessions[session_count]);
3597
3598 DBG("Getting all available session for UID %d GID %d",
3599 uid, gid);
3600 /*
3601 * Iterate over session list and append data after the control struct in
3602 * the buffer.
3603 */
3604 cds_list_for_each_entry(session, &list->head, list) {
3605 if (!session_get(session)) {
3606 continue;
3607 }
3608 /*
3609 * Only list the sessions the user can control.
3610 */
3611 if (!session_access_ok(session, uid, gid) ||
3612 session->destroyed) {
3613 session_put(session);
3614 continue;
3615 }
3616
3617 struct ltt_kernel_session *ksess = session->kernel_session;
3618 struct ltt_ust_session *usess = session->ust_session;
3619
3620 if (session->consumer->type == CONSUMER_DST_NET ||
3621 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3622 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3623 ret = build_network_session_path(sessions[i].path,
3624 sizeof(sessions[i].path), session);
3625 } else {
3626 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3627 session->consumer->dst.session_root_path);
3628 }
3629 if (ret < 0) {
3630 PERROR("snprintf session path");
3631 session_put(session);
3632 continue;
3633 }
3634
3635 strncpy(sessions[i].name, session->name, NAME_MAX);
3636 sessions[i].name[NAME_MAX - 1] = '\0';
3637 sessions[i].enabled = session->active;
3638 sessions[i].snapshot_mode = session->snapshot_mode;
3639 sessions[i].live_timer_interval = session->live_timer;
3640 extended[i].creation_time.value = (uint64_t) session->creation_time;
3641 extended[i].creation_time.is_set = 1;
3642 i++;
3643 session_put(session);
3644 }
3645 }
3646
3647 /*
3648 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3649 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3650 */
3651 int cmd_data_pending(struct ltt_session *session)
3652 {
3653 int ret;
3654 struct ltt_kernel_session *ksess = session->kernel_session;
3655 struct ltt_ust_session *usess = session->ust_session;
3656
3657 assert(session);
3658
3659 DBG("Data pending for session %s", session->name);
3660
3661 /* Session MUST be stopped to ask for data availability. */
3662 if (session->active) {
3663 ret = LTTNG_ERR_SESSION_STARTED;
3664 goto error;
3665 } else {
3666 /*
3667 * If stopped, just make sure we've started before else the above call
3668 * will always send that there is data pending.
3669 *
3670 * The consumer assumes that when the data pending command is received,
3671 * the trace has been started before or else no output data is written
3672 * by the streams which is a condition for data pending. So, this is
3673 * *VERY* important that we don't ask the consumer before a start
3674 * trace.
3675 */
3676 if (!session->has_been_started) {
3677 ret = 0;
3678 goto error;
3679 }
3680 }
3681
3682 /* A rotation is still pending, we have to wait. */
3683 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3684 DBG("Rotate still pending for session %s", session->name);
3685 ret = 1;
3686 goto error;
3687 }
3688
3689 if (ksess && ksess->consumer) {
3690 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3691 if (ret == 1) {
3692 /* Data is still being extracted for the kernel. */
3693 goto error;
3694 }
3695 }
3696
3697 if (usess && usess->consumer) {
3698 ret = consumer_is_data_pending(usess->id, usess->consumer);
3699 if (ret == 1) {
3700 /* Data is still being extracted for the kernel. */
3701 goto error;
3702 }
3703 }
3704
3705 /* Data is ready to be read by a viewer */
3706 ret = 0;
3707
3708 error:
3709 return ret;
3710 }
3711
3712 /*
3713 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3714 *
3715 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3716 */
3717 int cmd_snapshot_add_output(struct ltt_session *session,
3718 const struct lttng_snapshot_output *output, uint32_t *id)
3719 {
3720 int ret;
3721 struct snapshot_output *new_output;
3722
3723 assert(session);
3724 assert(output);
3725
3726 DBG("Cmd snapshot add output for session %s", session->name);
3727
3728 /*
3729 * Can't create an output if the session is not set in no-output mode.
3730 */
3731 if (session->output_traces) {
3732 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3733 goto error;
3734 }
3735
3736 if (session->has_non_mmap_channel) {
3737 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3738 goto error;
3739 }
3740
3741 /* Only one output is allowed until we have the "tee" feature. */
3742 if (session->snapshot.nb_output == 1) {
3743 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3744 goto error;
3745 }
3746
3747 new_output = snapshot_output_alloc();
3748 if (!new_output) {
3749 ret = LTTNG_ERR_NOMEM;
3750 goto error;
3751 }
3752
3753 ret = snapshot_output_init(session, output->max_size, output->name,
3754 output->ctrl_url, output->data_url, session->consumer, new_output,
3755 &session->snapshot);
3756 if (ret < 0) {
3757 if (ret == -ENOMEM) {
3758 ret = LTTNG_ERR_NOMEM;
3759 } else {
3760 ret = LTTNG_ERR_INVALID;
3761 }
3762 goto free_error;
3763 }
3764
3765 rcu_read_lock();
3766 snapshot_add_output</