325ffd2cf14f6ec3e320e402e8db17a6dac71adc
[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
25 #include <common/defaults.h>
26 #include <common/common.h>
27 #include <common/sessiond-comm/sessiond-comm.h>
28 #include <common/relayd/relayd.h>
29 #include <common/utils.h>
30 #include <common/compat/string.h>
31 #include <common/kernel-ctl/kernel-ctl.h>
32
33 #include "channel.h"
34 #include "consumer.h"
35 #include "event.h"
36 #include "health-sessiond.h"
37 #include "kernel.h"
38 #include "kernel-consumer.h"
39 #include "lttng-sessiond.h"
40 #include "utils.h"
41 #include "syscall.h"
42 #include "agent.h"
43 #include "buffer-registry.h"
44
45 #include "cmd.h"
46
47 /*
48 * Used to keep a unique index for each relayd socket created where this value
49 * is associated with streams on the consumer so it can match the right relayd
50 * to send to. It must be accessed with the relayd_net_seq_idx_lock
51 * held.
52 */
53 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
54 static uint64_t relayd_net_seq_idx;
55
56 static int validate_event_name(const char *);
57 static int validate_ust_event_name(const char *);
58 static int cmd_enable_event_internal(struct ltt_session *session,
59 struct lttng_domain *domain,
60 char *channel_name, struct lttng_event *event,
61 char *filter_expression,
62 struct lttng_filter_bytecode *filter,
63 struct lttng_event_exclusion *exclusion,
64 int wpipe);
65
66 /*
67 * Create a session path used by list_lttng_sessions for the case that the
68 * session consumer is on the network.
69 */
70 static int build_network_session_path(char *dst, size_t size,
71 struct ltt_session *session)
72 {
73 int ret, kdata_port, udata_port;
74 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
75 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
76
77 assert(session);
78 assert(dst);
79
80 memset(tmp_urls, 0, sizeof(tmp_urls));
81 memset(tmp_uurl, 0, sizeof(tmp_uurl));
82
83 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
84
85 if (session->kernel_session && session->kernel_session->consumer) {
86 kuri = &session->kernel_session->consumer->dst.net.control;
87 kdata_port = session->kernel_session->consumer->dst.net.data.port;
88 }
89
90 if (session->ust_session && session->ust_session->consumer) {
91 uuri = &session->ust_session->consumer->dst.net.control;
92 udata_port = session->ust_session->consumer->dst.net.data.port;
93 }
94
95 if (uuri == NULL && kuri == NULL) {
96 uri = &session->consumer->dst.net.control;
97 kdata_port = session->consumer->dst.net.data.port;
98 } else if (kuri && uuri) {
99 ret = uri_compare(kuri, uuri);
100 if (ret) {
101 /* Not Equal */
102 uri = kuri;
103 /* Build uuri URL string */
104 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
105 if (ret < 0) {
106 goto error;
107 }
108 } else {
109 uri = kuri;
110 }
111 } else if (kuri && uuri == NULL) {
112 uri = kuri;
113 } else if (uuri && kuri == NULL) {
114 uri = uuri;
115 }
116
117 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
118 if (ret < 0) {
119 goto error;
120 }
121
122 /*
123 * Do we have a UST url set. If yes, this means we have both kernel and UST
124 * to print.
125 */
126 if (*tmp_uurl != '\0') {
127 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
128 tmp_urls, kdata_port, tmp_uurl, udata_port);
129 } else {
130 int dport;
131 if (kuri || (!kuri && !uuri)) {
132 dport = kdata_port;
133 } else {
134 /* No kernel URI, use the UST port. */
135 dport = udata_port;
136 }
137 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
138 }
139
140 error:
141 return ret;
142 }
143
144 /*
145 * Get run-time attributes if the session has been started (discarded events,
146 * lost packets).
147 */
148 static int get_kernel_runtime_stats(struct ltt_session *session,
149 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
150 uint64_t *lost_packets)
151 {
152 int ret;
153
154 if (!session->has_been_started) {
155 ret = 0;
156 *discarded_events = 0;
157 *lost_packets = 0;
158 goto end;
159 }
160
161 ret = consumer_get_discarded_events(session->id, kchan->fd,
162 session->kernel_session->consumer,
163 discarded_events);
164 if (ret < 0) {
165 goto end;
166 }
167
168 ret = consumer_get_lost_packets(session->id, kchan->fd,
169 session->kernel_session->consumer,
170 lost_packets);
171 if (ret < 0) {
172 goto end;
173 }
174
175 end:
176 return ret;
177 }
178
179 /*
180 * Get run-time attributes if the session has been started (discarded events,
181 * lost packets).
182 */
183 static int get_ust_runtime_stats(struct ltt_session *session,
184 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
185 uint64_t *lost_packets)
186 {
187 int ret;
188 struct ltt_ust_session *usess;
189
190 if (!discarded_events || !lost_packets) {
191 ret = -1;
192 goto end;
193 }
194
195 usess = session->ust_session;
196 assert(discarded_events);
197 assert(lost_packets);
198
199 if (!usess || !session->has_been_started) {
200 *discarded_events = 0;
201 *lost_packets = 0;
202 ret = 0;
203 goto end;
204 }
205
206 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
207 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
208 &usess->buffer_reg_uid_list,
209 usess->consumer, uchan->id,
210 uchan->attr.overwrite,
211 discarded_events,
212 lost_packets);
213 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
214 ret = ust_app_pid_get_channel_runtime_stats(usess,
215 uchan, usess->consumer,
216 uchan->attr.overwrite,
217 discarded_events,
218 lost_packets);
219 if (ret < 0) {
220 goto end;
221 }
222 *discarded_events += uchan->per_pid_closed_app_discarded;
223 *lost_packets += uchan->per_pid_closed_app_lost;
224 } else {
225 ERR("Unsupported buffer type");
226 assert(0);
227 ret = -1;
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Fill lttng_channel array of all channels.
237 */
238 static void list_lttng_channels(enum lttng_domain_type domain,
239 struct ltt_session *session, struct lttng_channel *channels,
240 struct lttcomm_channel_extended *chan_exts)
241 {
242 int i = 0, ret;
243 struct ltt_kernel_channel *kchan;
244
245 DBG("Listing channels for session %s", session->name);
246
247 switch (domain) {
248 case LTTNG_DOMAIN_KERNEL:
249 /* Kernel channels */
250 if (session->kernel_session != NULL) {
251 cds_list_for_each_entry(kchan,
252 &session->kernel_session->channel_list.head, list) {
253 uint64_t discarded_events, lost_packets;
254
255 ret = get_kernel_runtime_stats(session, kchan,
256 &discarded_events, &lost_packets);
257 if (ret < 0) {
258 goto end;
259 }
260 /* Copy lttng_channel struct to array */
261 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
262 channels[i].enabled = kchan->enabled;
263 chan_exts[i].discarded_events =
264 discarded_events;
265 chan_exts[i].lost_packets = lost_packets;
266 i++;
267 }
268 }
269 break;
270 case LTTNG_DOMAIN_UST:
271 {
272 struct lttng_ht_iter iter;
273 struct ltt_ust_channel *uchan;
274
275 rcu_read_lock();
276 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
277 &iter.iter, uchan, node.node) {
278 uint64_t discarded_events = 0, lost_packets = 0;
279
280 if (lttng_strncpy(channels[i].name, uchan->name,
281 LTTNG_SYMBOL_NAME_LEN)) {
282 break;
283 }
284 channels[i].attr.overwrite = uchan->attr.overwrite;
285 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
286 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
287 channels[i].attr.switch_timer_interval =
288 uchan->attr.switch_timer_interval;
289 channels[i].attr.read_timer_interval =
290 uchan->attr.read_timer_interval;
291 channels[i].enabled = uchan->enabled;
292 channels[i].attr.tracefile_size = uchan->tracefile_size;
293 channels[i].attr.tracefile_count = uchan->tracefile_count;
294
295 /*
296 * Map enum lttng_ust_output to enum lttng_event_output.
297 */
298 switch (uchan->attr.output) {
299 case LTTNG_UST_MMAP:
300 channels[i].attr.output = LTTNG_EVENT_MMAP;
301 break;
302 default:
303 /*
304 * LTTNG_UST_MMAP is the only supported UST
305 * output mode.
306 */
307 assert(0);
308 break;
309 }
310
311 ret = get_ust_runtime_stats(session, uchan,
312 &discarded_events, &lost_packets);
313 if (ret < 0) {
314 break;
315 }
316 chan_exts[i].discarded_events = discarded_events;
317 chan_exts[i].lost_packets = lost_packets;
318 i++;
319 }
320 rcu_read_unlock();
321 break;
322 }
323 default:
324 break;
325 }
326
327 end:
328 return;
329 }
330
331 static void increment_extended_len(const char *filter_expression,
332 struct lttng_event_exclusion *exclusion, size_t *extended_len)
333 {
334 *extended_len += sizeof(struct lttcomm_event_extended_header);
335
336 if (filter_expression) {
337 *extended_len += strlen(filter_expression) + 1;
338 }
339
340 if (exclusion) {
341 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
342 }
343 }
344
345 static void append_extended_info(const char *filter_expression,
346 struct lttng_event_exclusion *exclusion, void **extended_at)
347 {
348 struct lttcomm_event_extended_header extended_header;
349 size_t filter_len = 0;
350 size_t nb_exclusions = 0;
351
352 if (filter_expression) {
353 filter_len = strlen(filter_expression) + 1;
354 }
355
356 if (exclusion) {
357 nb_exclusions = exclusion->count;
358 }
359
360 /* Set header fields */
361 extended_header.filter_len = filter_len;
362 extended_header.nb_exclusions = nb_exclusions;
363
364 /* Copy header */
365 memcpy(*extended_at, &extended_header, sizeof(extended_header));
366 *extended_at += sizeof(extended_header);
367
368 /* Copy filter string */
369 if (filter_expression) {
370 memcpy(*extended_at, filter_expression, filter_len);
371 *extended_at += filter_len;
372 }
373
374 /* Copy exclusion names */
375 if (exclusion) {
376 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
377
378 memcpy(*extended_at, &exclusion->names, len);
379 *extended_at += len;
380 }
381 }
382
383 /*
384 * Create a list of agent domain events.
385 *
386 * Return number of events in list on success or else a negative value.
387 */
388 static int list_lttng_agent_events(struct agent *agt,
389 struct lttng_event **events, size_t *total_size)
390 {
391 int i = 0, ret = 0;
392 unsigned int nb_event = 0;
393 struct agent_event *event;
394 struct lttng_event *tmp_events;
395 struct lttng_ht_iter iter;
396 size_t extended_len = 0;
397 void *extended_at;
398
399 assert(agt);
400 assert(events);
401
402 DBG3("Listing agent events");
403
404 rcu_read_lock();
405 nb_event = lttng_ht_get_count(agt->events);
406 rcu_read_unlock();
407 if (nb_event == 0) {
408 ret = nb_event;
409 *total_size = 0;
410 goto error;
411 }
412
413 /* Compute required extended infos size */
414 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
415
416 /*
417 * This is only valid because the commands which add events are
418 * processed in the same thread as the listing.
419 */
420 rcu_read_lock();
421 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
422 increment_extended_len(event->filter_expression, NULL,
423 &extended_len);
424 }
425 rcu_read_unlock();
426
427 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
428 tmp_events = zmalloc(*total_size);
429 if (!tmp_events) {
430 PERROR("zmalloc agent events session");
431 ret = -LTTNG_ERR_FATAL;
432 goto error;
433 }
434
435 extended_at = ((uint8_t *) tmp_events) +
436 nb_event * sizeof(struct lttng_event);
437
438 rcu_read_lock();
439 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
440 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
441 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
442 tmp_events[i].enabled = event->enabled;
443 tmp_events[i].loglevel = event->loglevel_value;
444 tmp_events[i].loglevel_type = event->loglevel_type;
445 i++;
446
447 /* Append extended info */
448 append_extended_info(event->filter_expression, NULL,
449 &extended_at);
450 }
451 rcu_read_unlock();
452
453 *events = tmp_events;
454 ret = nb_event;
455
456 error:
457 assert(nb_event == i);
458 return ret;
459 }
460
461 /*
462 * Create a list of ust global domain events.
463 */
464 static int list_lttng_ust_global_events(char *channel_name,
465 struct ltt_ust_domain_global *ust_global,
466 struct lttng_event **events, size_t *total_size)
467 {
468 int i = 0, ret = 0;
469 unsigned int nb_event = 0;
470 struct lttng_ht_iter iter;
471 struct lttng_ht_node_str *node;
472 struct ltt_ust_channel *uchan;
473 struct ltt_ust_event *uevent;
474 struct lttng_event *tmp;
475 size_t extended_len = 0;
476 void *extended_at;
477
478 DBG("Listing UST global events for channel %s", channel_name);
479
480 rcu_read_lock();
481
482 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
483 node = lttng_ht_iter_get_node_str(&iter);
484 if (node == NULL) {
485 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
486 goto end;
487 }
488
489 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
490
491 nb_event = lttng_ht_get_count(uchan->events);
492 if (nb_event == 0) {
493 ret = nb_event;
494 *total_size = 0;
495 goto end;
496 }
497
498 DBG3("Listing UST global %d events", nb_event);
499
500 /* Compute required extended infos size */
501 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
502 if (uevent->internal) {
503 nb_event--;
504 continue;
505 }
506
507 increment_extended_len(uevent->filter_expression,
508 uevent->exclusion, &extended_len);
509 }
510 if (nb_event == 0) {
511 /* All events are internal, skip. */
512 ret = 0;
513 *total_size = 0;
514 goto end;
515 }
516
517 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
518 tmp = zmalloc(*total_size);
519 if (tmp == NULL) {
520 ret = -LTTNG_ERR_FATAL;
521 goto end;
522 }
523
524 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
525
526 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
527 if (uevent->internal) {
528 /* This event should remain hidden from clients */
529 continue;
530 }
531 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
532 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
533 tmp[i].enabled = uevent->enabled;
534
535 switch (uevent->attr.instrumentation) {
536 case LTTNG_UST_TRACEPOINT:
537 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
538 break;
539 case LTTNG_UST_PROBE:
540 tmp[i].type = LTTNG_EVENT_PROBE;
541 break;
542 case LTTNG_UST_FUNCTION:
543 tmp[i].type = LTTNG_EVENT_FUNCTION;
544 break;
545 }
546
547 tmp[i].loglevel = uevent->attr.loglevel;
548 switch (uevent->attr.loglevel_type) {
549 case LTTNG_UST_LOGLEVEL_ALL:
550 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
551 break;
552 case LTTNG_UST_LOGLEVEL_RANGE:
553 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
554 break;
555 case LTTNG_UST_LOGLEVEL_SINGLE:
556 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
557 break;
558 }
559 if (uevent->filter) {
560 tmp[i].filter = 1;
561 }
562 if (uevent->exclusion) {
563 tmp[i].exclusion = 1;
564 }
565 i++;
566
567 /* Append extended info */
568 append_extended_info(uevent->filter_expression,
569 uevent->exclusion, &extended_at);
570 }
571
572 ret = nb_event;
573 *events = tmp;
574 end:
575 rcu_read_unlock();
576 return ret;
577 }
578
579 /*
580 * Fill lttng_event array of all kernel events in the channel.
581 */
582 static int list_lttng_kernel_events(char *channel_name,
583 struct ltt_kernel_session *kernel_session,
584 struct lttng_event **events, size_t *total_size)
585 {
586 int i = 0, ret;
587 unsigned int nb_event;
588 struct ltt_kernel_event *event;
589 struct ltt_kernel_channel *kchan;
590 size_t extended_len = 0;
591 void *extended_at;
592
593 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
594 if (kchan == NULL) {
595 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
596 goto error;
597 }
598
599 nb_event = kchan->event_count;
600
601 DBG("Listing events for channel %s", kchan->channel->name);
602
603 if (nb_event == 0) {
604 *total_size = 0;
605 *events = NULL;
606 goto end;
607 }
608
609 /* Compute required extended infos size */
610 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
611 increment_extended_len(event->filter_expression, NULL,
612 &extended_len);
613 }
614
615 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
616 *events = zmalloc(*total_size);
617 if (*events == NULL) {
618 ret = LTTNG_ERR_FATAL;
619 goto error;
620 }
621
622 extended_at = ((void *) *events) +
623 nb_event * sizeof(struct lttng_event);
624
625 /* Kernel channels */
626 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
627 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
628 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
629 (*events)[i].enabled = event->enabled;
630 (*events)[i].filter =
631 (unsigned char) !!event->filter_expression;
632
633 switch (event->event->instrumentation) {
634 case LTTNG_KERNEL_TRACEPOINT:
635 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
636 break;
637 case LTTNG_KERNEL_KRETPROBE:
638 (*events)[i].type = LTTNG_EVENT_FUNCTION;
639 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
640 sizeof(struct lttng_kernel_kprobe));
641 break;
642 case LTTNG_KERNEL_KPROBE:
643 (*events)[i].type = LTTNG_EVENT_PROBE;
644 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
645 sizeof(struct lttng_kernel_kprobe));
646 break;
647 case LTTNG_KERNEL_FUNCTION:
648 (*events)[i].type = LTTNG_EVENT_FUNCTION;
649 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
650 sizeof(struct lttng_kernel_function));
651 break;
652 case LTTNG_KERNEL_NOOP:
653 (*events)[i].type = LTTNG_EVENT_NOOP;
654 break;
655 case LTTNG_KERNEL_SYSCALL:
656 (*events)[i].type = LTTNG_EVENT_SYSCALL;
657 break;
658 case LTTNG_KERNEL_ALL:
659 assert(0);
660 break;
661 }
662 i++;
663
664 /* Append extended info */
665 append_extended_info(event->filter_expression, NULL,
666 &extended_at);
667 }
668
669 end:
670 return nb_event;
671
672 error:
673 /* Negate the error code to differentiate the size from an error */
674 return -ret;
675 }
676
677 /*
678 * Add URI so the consumer output object. Set the correct path depending on the
679 * domain adding the default trace directory.
680 */
681 static int add_uri_to_consumer(struct consumer_output *consumer,
682 struct lttng_uri *uri, enum lttng_domain_type domain,
683 const char *session_name)
684 {
685 int ret = LTTNG_OK;
686 const char *default_trace_dir;
687
688 assert(uri);
689
690 if (consumer == NULL) {
691 DBG("No consumer detected. Don't add URI. Stopping.");
692 ret = LTTNG_ERR_NO_CONSUMER;
693 goto error;
694 }
695
696 switch (domain) {
697 case LTTNG_DOMAIN_KERNEL:
698 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
699 break;
700 case LTTNG_DOMAIN_UST:
701 default_trace_dir = DEFAULT_UST_TRACE_DIR;
702 break;
703 default:
704 /*
705 * This case is possible is we try to add the URI to the global tracing
706 * session consumer object which in this case there is no subdir.
707 */
708 default_trace_dir = "";
709 }
710
711 switch (uri->dtype) {
712 case LTTNG_DST_IPV4:
713 case LTTNG_DST_IPV6:
714 DBG2("Setting network URI to consumer");
715
716 if (consumer->type == CONSUMER_DST_NET) {
717 if ((uri->stype == LTTNG_STREAM_CONTROL &&
718 consumer->dst.net.control_isset) ||
719 (uri->stype == LTTNG_STREAM_DATA &&
720 consumer->dst.net.data_isset)) {
721 ret = LTTNG_ERR_URL_EXIST;
722 goto error;
723 }
724 } else {
725 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
726 }
727
728 consumer->type = CONSUMER_DST_NET;
729
730 /* Set URI into consumer output object */
731 ret = consumer_set_network_uri(consumer, uri);
732 if (ret < 0) {
733 ret = -ret;
734 goto error;
735 } else if (ret == 1) {
736 /*
737 * URI was the same in the consumer so we do not append the subdir
738 * again so to not duplicate output dir.
739 */
740 ret = LTTNG_OK;
741 goto error;
742 }
743
744 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
745 ret = consumer_set_subdir(consumer, session_name);
746 if (ret < 0) {
747 ret = LTTNG_ERR_FATAL;
748 goto error;
749 }
750 }
751
752 if (uri->stype == LTTNG_STREAM_CONTROL) {
753 /* On a new subdir, reappend the default trace dir. */
754 strncat(consumer->subdir, default_trace_dir,
755 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
756 DBG3("Append domain trace name to subdir %s", consumer->subdir);
757 }
758
759 break;
760 case LTTNG_DST_PATH:
761 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
762 memset(consumer->dst.trace_path, 0,
763 sizeof(consumer->dst.trace_path));
764 /* Explicit length checks for strcpy and strcat. */
765 if (strlen(uri->dst.path) + strlen(default_trace_dir)
766 >= sizeof(consumer->dst.trace_path)) {
767 ret = LTTNG_ERR_FATAL;
768 goto error;
769 }
770 strcpy(consumer->dst.trace_path, uri->dst.path);
771 /* Append default trace dir */
772 strcat(consumer->dst.trace_path, default_trace_dir);
773 /* Flag consumer as local. */
774 consumer->type = CONSUMER_DST_LOCAL;
775 break;
776 }
777
778 ret = LTTNG_OK;
779
780 error:
781 return ret;
782 }
783
784 /*
785 * Init tracing by creating trace directory and sending fds kernel consumer.
786 */
787 static int init_kernel_tracing(struct ltt_kernel_session *session)
788 {
789 int ret = 0;
790 struct lttng_ht_iter iter;
791 struct consumer_socket *socket;
792
793 assert(session);
794
795 rcu_read_lock();
796
797 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
798 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
799 socket, node.node) {
800 pthread_mutex_lock(socket->lock);
801 ret = kernel_consumer_send_session(socket, session);
802 pthread_mutex_unlock(socket->lock);
803 if (ret < 0) {
804 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
805 goto error;
806 }
807 }
808 }
809
810 error:
811 rcu_read_unlock();
812 return ret;
813 }
814
815 /*
816 * Create a socket to the relayd using the URI.
817 *
818 * On success, the relayd_sock pointer is set to the created socket.
819 * Else, it's stays untouched and a lttcomm error code is returned.
820 */
821 static int create_connect_relayd(struct lttng_uri *uri,
822 struct lttcomm_relayd_sock **relayd_sock,
823 struct consumer_output *consumer)
824 {
825 int ret;
826 struct lttcomm_relayd_sock *rsock;
827
828 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
829 RELAYD_VERSION_COMM_MINOR);
830 if (!rsock) {
831 ret = LTTNG_ERR_FATAL;
832 goto error;
833 }
834
835 /*
836 * Connect to relayd so we can proceed with a session creation. This call
837 * can possibly block for an arbitrary amount of time to set the health
838 * state to be in poll execution.
839 */
840 health_poll_entry();
841 ret = relayd_connect(rsock);
842 health_poll_exit();
843 if (ret < 0) {
844 ERR("Unable to reach lttng-relayd");
845 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
846 goto free_sock;
847 }
848
849 /* Create socket for control stream. */
850 if (uri->stype == LTTNG_STREAM_CONTROL) {
851 DBG3("Creating relayd stream socket from URI");
852
853 /* Check relayd version */
854 ret = relayd_version_check(rsock);
855 if (ret < 0) {
856 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
857 goto close_sock;
858 }
859 consumer->relay_major_version = rsock->major;
860 consumer->relay_minor_version = rsock->minor;
861 } else if (uri->stype == LTTNG_STREAM_DATA) {
862 DBG3("Creating relayd data socket from URI");
863 } else {
864 /* Command is not valid */
865 ERR("Relayd invalid stream type: %d", uri->stype);
866 ret = LTTNG_ERR_INVALID;
867 goto close_sock;
868 }
869
870 *relayd_sock = rsock;
871
872 return LTTNG_OK;
873
874 close_sock:
875 /* The returned value is not useful since we are on an error path. */
876 (void) relayd_close(rsock);
877 free_sock:
878 free(rsock);
879 error:
880 return ret;
881 }
882
883 /*
884 * Connect to the relayd using URI and send the socket to the right consumer.
885 */
886 static int send_consumer_relayd_socket(enum lttng_domain_type domain,
887 unsigned int session_id, struct lttng_uri *relayd_uri,
888 struct consumer_output *consumer,
889 struct consumer_socket *consumer_sock,
890 char *session_name, char *hostname, int session_live_timer)
891 {
892 int ret;
893 struct lttcomm_relayd_sock *rsock = NULL;
894
895 /* Connect to relayd and make version check if uri is the control. */
896 ret = create_connect_relayd(relayd_uri, &rsock, consumer);
897 if (ret != LTTNG_OK) {
898 goto error;
899 }
900 assert(rsock);
901
902 /* Set the network sequence index if not set. */
903 if (consumer->net_seq_index == (uint64_t) -1ULL) {
904 pthread_mutex_lock(&relayd_net_seq_idx_lock);
905 /*
906 * Increment net_seq_idx because we are about to transfer the
907 * new relayd socket to the consumer.
908 * Assign unique key so the consumer can match streams.
909 */
910 consumer->net_seq_index = ++relayd_net_seq_idx;
911 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
912 }
913
914 /* Send relayd socket to consumer. */
915 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
916 relayd_uri->stype, session_id,
917 session_name, hostname, session_live_timer);
918 if (ret < 0) {
919 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
920 goto close_sock;
921 }
922
923 /* Flag that the corresponding socket was sent. */
924 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
925 consumer_sock->control_sock_sent = 1;
926 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
927 consumer_sock->data_sock_sent = 1;
928 }
929
930 ret = LTTNG_OK;
931
932 /*
933 * Close socket which was dup on the consumer side. The session daemon does
934 * NOT keep track of the relayd socket(s) once transfer to the consumer.
935 */
936
937 close_sock:
938 (void) relayd_close(rsock);
939 free(rsock);
940
941 error:
942 if (ret != LTTNG_OK) {
943 /*
944 * The consumer output for this session should not be used anymore
945 * since the relayd connection failed thus making any tracing or/and
946 * streaming not usable.
947 */
948 consumer->enabled = 0;
949 }
950 return ret;
951 }
952
953 /*
954 * Send both relayd sockets to a specific consumer and domain. This is a
955 * helper function to facilitate sending the information to the consumer for a
956 * session.
957 */
958 static int send_consumer_relayd_sockets(enum lttng_domain_type domain,
959 unsigned int session_id, struct consumer_output *consumer,
960 struct consumer_socket *sock, char *session_name,
961 char *hostname, int session_live_timer)
962 {
963 int ret = LTTNG_OK;
964
965 assert(consumer);
966 assert(sock);
967
968 /* Sending control relayd socket. */
969 if (!sock->control_sock_sent) {
970 ret = send_consumer_relayd_socket(domain, session_id,
971 &consumer->dst.net.control, consumer, sock,
972 session_name, hostname, session_live_timer);
973 if (ret != LTTNG_OK) {
974 goto error;
975 }
976 }
977
978 /* Sending data relayd socket. */
979 if (!sock->data_sock_sent) {
980 ret = send_consumer_relayd_socket(domain, session_id,
981 &consumer->dst.net.data, consumer, sock,
982 session_name, hostname, session_live_timer);
983 if (ret != LTTNG_OK) {
984 goto error;
985 }
986 }
987
988 error:
989 return ret;
990 }
991
992 /*
993 * Setup relayd connections for a tracing session. First creates the socket to
994 * the relayd and send them to the right domain consumer. Consumer type MUST be
995 * network.
996 */
997 int cmd_setup_relayd(struct ltt_session *session)
998 {
999 int ret = LTTNG_OK;
1000 struct ltt_ust_session *usess;
1001 struct ltt_kernel_session *ksess;
1002 struct consumer_socket *socket;
1003 struct lttng_ht_iter iter;
1004
1005 assert(session);
1006
1007 usess = session->ust_session;
1008 ksess = session->kernel_session;
1009
1010 DBG("Setting relayd for session %s", session->name);
1011
1012 rcu_read_lock();
1013
1014 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1015 && usess->consumer->enabled) {
1016 /* For each consumer socket, send relayd sockets */
1017 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1018 socket, node.node) {
1019 pthread_mutex_lock(socket->lock);
1020 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1021 usess->consumer, socket,
1022 session->name, session->hostname,
1023 session->live_timer);
1024 pthread_mutex_unlock(socket->lock);
1025 if (ret != LTTNG_OK) {
1026 goto error;
1027 }
1028 /* Session is now ready for network streaming. */
1029 session->net_handle = 1;
1030 }
1031 session->consumer->relay_major_version =
1032 usess->consumer->relay_major_version;
1033 session->consumer->relay_minor_version =
1034 usess->consumer->relay_minor_version;
1035 }
1036
1037 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1038 && ksess->consumer->enabled) {
1039 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1040 socket, node.node) {
1041 pthread_mutex_lock(socket->lock);
1042 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1043 ksess->consumer, socket,
1044 session->name, session->hostname,
1045 session->live_timer);
1046 pthread_mutex_unlock(socket->lock);
1047 if (ret != LTTNG_OK) {
1048 goto error;
1049 }
1050 /* Session is now ready for network streaming. */
1051 session->net_handle = 1;
1052 }
1053 session->consumer->relay_major_version =
1054 ksess->consumer->relay_major_version;
1055 session->consumer->relay_minor_version =
1056 ksess->consumer->relay_minor_version;
1057 }
1058
1059 error:
1060 rcu_read_unlock();
1061 return ret;
1062 }
1063
1064 /*
1065 * Start a kernel session by opening all necessary streams.
1066 */
1067 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1068 {
1069 int ret;
1070 struct ltt_kernel_channel *kchan;
1071
1072 /* Open kernel metadata */
1073 if (ksess->metadata == NULL && ksess->output_traces) {
1074 ret = kernel_open_metadata(ksess);
1075 if (ret < 0) {
1076 ret = LTTNG_ERR_KERN_META_FAIL;
1077 goto error;
1078 }
1079 }
1080
1081 /* Open kernel metadata stream */
1082 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1083 ret = kernel_open_metadata_stream(ksess);
1084 if (ret < 0) {
1085 ERR("Kernel create metadata stream failed");
1086 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1087 goto error;
1088 }
1089 }
1090
1091 /* For each channel */
1092 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1093 if (kchan->stream_count == 0) {
1094 ret = kernel_open_channel_stream(kchan);
1095 if (ret < 0) {
1096 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1097 goto error;
1098 }
1099 /* Update the stream global counter */
1100 ksess->stream_count_global += ret;
1101 }
1102 }
1103
1104 /* Setup kernel consumer socket and send fds to it */
1105 ret = init_kernel_tracing(ksess);
1106 if (ret != 0) {
1107 ret = LTTNG_ERR_KERN_START_FAIL;
1108 goto error;
1109 }
1110
1111 /* This start the kernel tracing */
1112 ret = kernel_start_session(ksess);
1113 if (ret < 0) {
1114 ret = LTTNG_ERR_KERN_START_FAIL;
1115 goto error;
1116 }
1117
1118 /* Quiescent wait after starting trace */
1119 kernel_wait_quiescent(kernel_tracer_fd);
1120
1121 ksess->active = 1;
1122
1123 ret = LTTNG_OK;
1124
1125 error:
1126 return ret;
1127 }
1128
1129 /*
1130 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1131 */
1132 int cmd_disable_channel(struct ltt_session *session,
1133 enum lttng_domain_type domain, char *channel_name)
1134 {
1135 int ret;
1136 struct ltt_ust_session *usess;
1137
1138 usess = session->ust_session;
1139
1140 rcu_read_lock();
1141
1142 switch (domain) {
1143 case LTTNG_DOMAIN_KERNEL:
1144 {
1145 ret = channel_kernel_disable(session->kernel_session,
1146 channel_name);
1147 if (ret != LTTNG_OK) {
1148 goto error;
1149 }
1150
1151 kernel_wait_quiescent(kernel_tracer_fd);
1152 break;
1153 }
1154 case LTTNG_DOMAIN_UST:
1155 {
1156 struct ltt_ust_channel *uchan;
1157 struct lttng_ht *chan_ht;
1158
1159 chan_ht = usess->domain_global.channels;
1160
1161 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1162 if (uchan == NULL) {
1163 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1164 goto error;
1165 }
1166
1167 ret = channel_ust_disable(usess, uchan);
1168 if (ret != LTTNG_OK) {
1169 goto error;
1170 }
1171 break;
1172 }
1173 default:
1174 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1175 goto error;
1176 }
1177
1178 ret = LTTNG_OK;
1179
1180 error:
1181 rcu_read_unlock();
1182 return ret;
1183 }
1184
1185 /*
1186 * Command LTTNG_TRACK_PID processed by the client thread.
1187 *
1188 * Called with session lock held.
1189 */
1190 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1191 int pid)
1192 {
1193 int ret;
1194
1195 rcu_read_lock();
1196
1197 switch (domain) {
1198 case LTTNG_DOMAIN_KERNEL:
1199 {
1200 struct ltt_kernel_session *ksess;
1201
1202 ksess = session->kernel_session;
1203
1204 ret = kernel_track_pid(ksess, pid);
1205 if (ret != LTTNG_OK) {
1206 goto error;
1207 }
1208
1209 kernel_wait_quiescent(kernel_tracer_fd);
1210 break;
1211 }
1212 case LTTNG_DOMAIN_UST:
1213 {
1214 struct ltt_ust_session *usess;
1215
1216 usess = session->ust_session;
1217
1218 ret = trace_ust_track_pid(usess, pid);
1219 if (ret != LTTNG_OK) {
1220 goto error;
1221 }
1222 break;
1223 }
1224 default:
1225 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1226 goto error;
1227 }
1228
1229 ret = LTTNG_OK;
1230
1231 error:
1232 rcu_read_unlock();
1233 return ret;
1234 }
1235
1236 /*
1237 * Command LTTNG_UNTRACK_PID processed by the client thread.
1238 *
1239 * Called with session lock held.
1240 */
1241 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1242 int pid)
1243 {
1244 int ret;
1245
1246 rcu_read_lock();
1247
1248 switch (domain) {
1249 case LTTNG_DOMAIN_KERNEL:
1250 {
1251 struct ltt_kernel_session *ksess;
1252
1253 ksess = session->kernel_session;
1254
1255 ret = kernel_untrack_pid(ksess, pid);
1256 if (ret != LTTNG_OK) {
1257 goto error;
1258 }
1259
1260 kernel_wait_quiescent(kernel_tracer_fd);
1261 break;
1262 }
1263 case LTTNG_DOMAIN_UST:
1264 {
1265 struct ltt_ust_session *usess;
1266
1267 usess = session->ust_session;
1268
1269 ret = trace_ust_untrack_pid(usess, pid);
1270 if (ret != LTTNG_OK) {
1271 goto error;
1272 }
1273 break;
1274 }
1275 default:
1276 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1277 goto error;
1278 }
1279
1280 ret = LTTNG_OK;
1281
1282 error:
1283 rcu_read_unlock();
1284 return ret;
1285 }
1286
1287 /*
1288 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1289 *
1290 * The wpipe arguments is used as a notifier for the kernel thread.
1291 */
1292 int cmd_enable_channel(struct ltt_session *session,
1293 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1294 {
1295 int ret;
1296 struct ltt_ust_session *usess = session->ust_session;
1297 struct lttng_ht *chan_ht;
1298 size_t len;
1299
1300 assert(session);
1301 assert(attr);
1302 assert(domain);
1303
1304 len = lttng_strnlen(attr->name, sizeof(attr->name));
1305
1306 /* Validate channel name */
1307 if (attr->name[0] == '.' ||
1308 memchr(attr->name, '/', len) != NULL) {
1309 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1310 goto end;
1311 }
1312
1313 DBG("Enabling channel %s for session %s", attr->name, session->name);
1314
1315 rcu_read_lock();
1316
1317 /*
1318 * Don't try to enable a channel if the session has been started at
1319 * some point in time before. The tracer does not allow it.
1320 */
1321 if (session->has_been_started) {
1322 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1323 goto error;
1324 }
1325
1326 /*
1327 * If the session is a live session, remove the switch timer, the
1328 * live timer does the same thing but sends also synchronisation
1329 * beacons for inactive streams.
1330 */
1331 if (session->live_timer > 0) {
1332 attr->attr.live_timer_interval = session->live_timer;
1333 attr->attr.switch_timer_interval = 0;
1334 }
1335
1336 switch (domain->type) {
1337 case LTTNG_DOMAIN_KERNEL:
1338 {
1339 struct ltt_kernel_channel *kchan;
1340
1341 kchan = trace_kernel_get_channel_by_name(attr->name,
1342 session->kernel_session);
1343 if (kchan == NULL) {
1344 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1345 if (attr->name[0] != '\0') {
1346 session->kernel_session->has_non_default_channel = 1;
1347 }
1348 } else {
1349 ret = channel_kernel_enable(session->kernel_session, kchan);
1350 }
1351
1352 if (ret != LTTNG_OK) {
1353 goto error;
1354 }
1355
1356 kernel_wait_quiescent(kernel_tracer_fd);
1357 break;
1358 }
1359 case LTTNG_DOMAIN_UST:
1360 case LTTNG_DOMAIN_JUL:
1361 case LTTNG_DOMAIN_LOG4J:
1362 case LTTNG_DOMAIN_PYTHON:
1363 {
1364 struct ltt_ust_channel *uchan;
1365
1366 /*
1367 * FIXME
1368 *
1369 * Current agent implementation limitations force us to allow
1370 * only one channel at once in "agent" subdomains. Each
1371 * subdomain has a default channel name which must be strictly
1372 * adhered to.
1373 */
1374 if (domain->type == LTTNG_DOMAIN_JUL) {
1375 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1376 LTTNG_SYMBOL_NAME_LEN)) {
1377 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1378 goto error;
1379 }
1380 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1381 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1382 LTTNG_SYMBOL_NAME_LEN)) {
1383 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1384 goto error;
1385 }
1386 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1387 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1388 LTTNG_SYMBOL_NAME_LEN)) {
1389 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1390 goto error;
1391 }
1392 }
1393
1394 chan_ht = usess->domain_global.channels;
1395
1396 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1397 if (uchan == NULL) {
1398 ret = channel_ust_create(usess, attr, domain->buf_type);
1399 if (attr->name[0] != '\0') {
1400 usess->has_non_default_channel = 1;
1401 }
1402 } else {
1403 ret = channel_ust_enable(usess, uchan);
1404 }
1405 break;
1406 }
1407 default:
1408 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1409 goto error;
1410 }
1411
1412 error:
1413 rcu_read_unlock();
1414 end:
1415 return ret;
1416 }
1417
1418 /*
1419 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1420 */
1421 int cmd_disable_event(struct ltt_session *session,
1422 enum lttng_domain_type domain, char *channel_name,
1423 struct lttng_event *event)
1424 {
1425 int ret;
1426 char *event_name;
1427
1428 DBG("Disable event command for event \'%s\'", event->name);
1429
1430 event_name = event->name;
1431 if (validate_event_name(event_name)) {
1432 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1433 goto error;
1434 }
1435
1436 /* Error out on unhandled search criteria */
1437 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1438 || event->pid || event->filter || event->exclusion) {
1439 ret = LTTNG_ERR_UNK;
1440 goto error;
1441 }
1442
1443 rcu_read_lock();
1444
1445 switch (domain) {
1446 case LTTNG_DOMAIN_KERNEL:
1447 {
1448 struct ltt_kernel_channel *kchan;
1449 struct ltt_kernel_session *ksess;
1450
1451 ksess = session->kernel_session;
1452
1453 /*
1454 * If a non-default channel has been created in the
1455 * session, explicitely require that -c chan_name needs
1456 * to be provided.
1457 */
1458 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1459 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1460 goto error_unlock;
1461 }
1462
1463 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1464 if (kchan == NULL) {
1465 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1466 goto error_unlock;
1467 }
1468
1469 switch (event->type) {
1470 case LTTNG_EVENT_ALL:
1471 case LTTNG_EVENT_TRACEPOINT:
1472 case LTTNG_EVENT_SYSCALL:
1473 case LTTNG_EVENT_PROBE:
1474 case LTTNG_EVENT_FUNCTION:
1475 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1476 if (event_name[0] == '\0') {
1477 ret = event_kernel_disable_event(kchan,
1478 NULL, event->type);
1479 } else {
1480 ret = event_kernel_disable_event(kchan,
1481 event_name, event->type);
1482 }
1483 if (ret != LTTNG_OK) {
1484 goto error_unlock;
1485 }
1486 break;
1487 default:
1488 ret = LTTNG_ERR_UNK;
1489 goto error_unlock;
1490 }
1491
1492 kernel_wait_quiescent(kernel_tracer_fd);
1493 break;
1494 }
1495 case LTTNG_DOMAIN_UST:
1496 {
1497 struct ltt_ust_channel *uchan;
1498 struct ltt_ust_session *usess;
1499
1500 usess = session->ust_session;
1501
1502 if (validate_ust_event_name(event_name)) {
1503 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1504 goto error_unlock;
1505 }
1506
1507 /*
1508 * If a non-default channel has been created in the
1509 * session, explicitly require that -c chan_name needs
1510 * to be provided.
1511 */
1512 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1513 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1514 goto error_unlock;
1515 }
1516
1517 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1518 channel_name);
1519 if (uchan == NULL) {
1520 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1521 goto error_unlock;
1522 }
1523
1524 switch (event->type) {
1525 case LTTNG_EVENT_ALL:
1526 /*
1527 * An empty event name means that everything
1528 * should be disabled.
1529 */
1530 if (event->name[0] == '\0') {
1531 ret = event_ust_disable_all_tracepoints(usess, uchan);
1532 } else {
1533 ret = event_ust_disable_tracepoint(usess, uchan,
1534 event_name);
1535 }
1536 if (ret != LTTNG_OK) {
1537 goto error_unlock;
1538 }
1539 break;
1540 default:
1541 ret = LTTNG_ERR_UNK;
1542 goto error_unlock;
1543 }
1544
1545 DBG3("Disable UST event %s in channel %s completed", event_name,
1546 channel_name);
1547 break;
1548 }
1549 case LTTNG_DOMAIN_LOG4J:
1550 case LTTNG_DOMAIN_JUL:
1551 case LTTNG_DOMAIN_PYTHON:
1552 {
1553 struct agent *agt;
1554 struct ltt_ust_session *usess = session->ust_session;
1555
1556 assert(usess);
1557
1558 switch (event->type) {
1559 case LTTNG_EVENT_ALL:
1560 break;
1561 default:
1562 ret = LTTNG_ERR_UNK;
1563 goto error_unlock;
1564 }
1565
1566 agt = trace_ust_find_agent(usess, domain);
1567 if (!agt) {
1568 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1569 goto error_unlock;
1570 }
1571 /*
1572 * An empty event name means that everything
1573 * should be disabled.
1574 */
1575 if (event->name[0] == '\0') {
1576 ret = event_agent_disable_all(usess, agt);
1577 } else {
1578 ret = event_agent_disable(usess, agt, event_name);
1579 }
1580 if (ret != LTTNG_OK) {
1581 goto error_unlock;
1582 }
1583
1584 break;
1585 }
1586 default:
1587 ret = LTTNG_ERR_UND;
1588 goto error_unlock;
1589 }
1590
1591 ret = LTTNG_OK;
1592
1593 error_unlock:
1594 rcu_read_unlock();
1595 error:
1596 return ret;
1597 }
1598
1599 /*
1600 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1601 */
1602 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1603 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1604 {
1605 int ret, chan_kern_created = 0, chan_ust_created = 0;
1606 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1607
1608 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1609 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1610 app_ctx_name = ctx->u.app_ctx.ctx_name;
1611 }
1612
1613 switch (domain) {
1614 case LTTNG_DOMAIN_KERNEL:
1615 assert(session->kernel_session);
1616
1617 if (session->kernel_session->channel_count == 0) {
1618 /* Create default channel */
1619 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1620 if (ret != LTTNG_OK) {
1621 goto error;
1622 }
1623 chan_kern_created = 1;
1624 }
1625 /* Add kernel context to kernel tracer */
1626 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1627 if (ret != LTTNG_OK) {
1628 goto error;
1629 }
1630 break;
1631 case LTTNG_DOMAIN_JUL:
1632 case LTTNG_DOMAIN_LOG4J:
1633 {
1634 /*
1635 * Validate channel name.
1636 * If no channel name is given and the domain is JUL or LOG4J,
1637 * set it to the appropriate domain-specific channel name. If
1638 * a name is provided but does not match the expexted channel
1639 * name, return an error.
1640 */
1641 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1642 strcmp(channel_name,
1643 DEFAULT_JUL_CHANNEL_NAME)) {
1644 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1645 goto error;
1646 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1647 strcmp(channel_name,
1648 DEFAULT_LOG4J_CHANNEL_NAME)) {
1649 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1650 goto error;
1651 }
1652 /* break is _not_ missing here. */
1653 }
1654 case LTTNG_DOMAIN_UST:
1655 {
1656 struct ltt_ust_session *usess = session->ust_session;
1657 unsigned int chan_count;
1658
1659 assert(usess);
1660
1661 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1662 if (chan_count == 0) {
1663 struct lttng_channel *attr;
1664 /* Create default channel */
1665 attr = channel_new_default_attr(domain, usess->buffer_type);
1666 if (attr == NULL) {
1667 ret = LTTNG_ERR_FATAL;
1668 goto error;
1669 }
1670
1671 ret = channel_ust_create(usess, attr, usess->buffer_type);
1672 if (ret != LTTNG_OK) {
1673 free(attr);
1674 goto error;
1675 }
1676 free(attr);
1677 chan_ust_created = 1;
1678 }
1679
1680 ret = context_ust_add(usess, domain, ctx, channel_name);
1681 free(app_ctx_provider_name);
1682 free(app_ctx_name);
1683 app_ctx_name = NULL;
1684 app_ctx_provider_name = NULL;
1685 if (ret != LTTNG_OK) {
1686 goto error;
1687 }
1688 break;
1689 }
1690 default:
1691 ret = LTTNG_ERR_UND;
1692 goto error;
1693 }
1694
1695 ret = LTTNG_OK;
1696 goto end;
1697
1698 error:
1699 if (chan_kern_created) {
1700 struct ltt_kernel_channel *kchan =
1701 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1702 session->kernel_session);
1703 /* Created previously, this should NOT fail. */
1704 assert(kchan);
1705 kernel_destroy_channel(kchan);
1706 }
1707
1708 if (chan_ust_created) {
1709 struct ltt_ust_channel *uchan =
1710 trace_ust_find_channel_by_name(
1711 session->ust_session->domain_global.channels,
1712 DEFAULT_CHANNEL_NAME);
1713 /* Created previously, this should NOT fail. */
1714 assert(uchan);
1715 /* Remove from the channel list of the session. */
1716 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1717 uchan);
1718 trace_ust_destroy_channel(uchan);
1719 }
1720 end:
1721 free(app_ctx_provider_name);
1722 free(app_ctx_name);
1723 return ret;
1724 }
1725
1726 static int validate_event_name(const char *name)
1727 {
1728 int ret = 0;
1729 const char *c = name;
1730 const char *event_name_end = c + LTTNG_SYMBOL_NAME_LEN;
1731 bool null_terminated = false;
1732
1733 /*
1734 * Make sure that unescaped wildcards are only used as the last
1735 * character of the event name.
1736 */
1737 while (c < event_name_end) {
1738 switch (*c) {
1739 case '\0':
1740 null_terminated = true;
1741 goto end;
1742 case '\\':
1743 c++;
1744 break;
1745 case '*':
1746 if ((c + 1) < event_name_end && *(c + 1)) {
1747 /* Wildcard is not the last character */
1748 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1749 goto end;
1750 }
1751 default:
1752 break;
1753 }
1754 c++;
1755 }
1756 end:
1757 if (!ret && !null_terminated) {
1758 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1759 }
1760 return ret;
1761 }
1762
1763 static inline bool name_starts_with(const char *name, const char *prefix)
1764 {
1765 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1766
1767 return !strncmp(name, prefix, max_cmp_len);
1768 }
1769
1770 /* Perform userspace-specific event name validation */
1771 static int validate_ust_event_name(const char *name)
1772 {
1773 int ret = 0;
1774
1775 if (!name) {
1776 ret = -1;
1777 goto end;
1778 }
1779
1780 /*
1781 * Check name against all internal UST event component namespaces used
1782 * by the agents.
1783 */
1784 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1785 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1786 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1787 ret = -1;
1788 }
1789
1790 end:
1791 return ret;
1792 }
1793
1794 /*
1795 * Internal version of cmd_enable_event() with a supplemental
1796 * "internal_event" flag which is used to enable internal events which should
1797 * be hidden from clients. Such events are used in the agent implementation to
1798 * enable the events through which all "agent" events are funeled.
1799 */
1800 static int _cmd_enable_event(struct ltt_session *session,
1801 struct lttng_domain *domain,
1802 char *channel_name, struct lttng_event *event,
1803 char *filter_expression,
1804 struct lttng_filter_bytecode *filter,
1805 struct lttng_event_exclusion *exclusion,
1806 int wpipe, bool internal_event)
1807 {
1808 int ret, channel_created = 0;
1809 struct lttng_channel *attr = NULL;
1810
1811 assert(session);
1812 assert(event);
1813 assert(channel_name);
1814
1815 /* If we have a filter, we must have its filter expression */
1816 assert(!(!!filter_expression ^ !!filter));
1817
1818 DBG("Enable event command for event \'%s\'", event->name);
1819
1820 rcu_read_lock();
1821
1822 ret = validate_event_name(event->name);
1823 if (ret) {
1824 goto error;
1825 }
1826
1827 switch (domain->type) {
1828 case LTTNG_DOMAIN_KERNEL:
1829 {
1830 struct ltt_kernel_channel *kchan;
1831
1832 /*
1833 * If a non-default channel has been created in the
1834 * session, explicitely require that -c chan_name needs
1835 * to be provided.
1836 */
1837 if (session->kernel_session->has_non_default_channel
1838 && channel_name[0] == '\0') {
1839 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1840 goto error;
1841 }
1842
1843 kchan = trace_kernel_get_channel_by_name(channel_name,
1844 session->kernel_session);
1845 if (kchan == NULL) {
1846 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
1847 LTTNG_BUFFER_GLOBAL);
1848 if (attr == NULL) {
1849 ret = LTTNG_ERR_FATAL;
1850 goto error;
1851 }
1852 if (lttng_strncpy(attr->name, channel_name,
1853 sizeof(attr->name))) {
1854 ret = LTTNG_ERR_INVALID;
1855 goto error;
1856 }
1857
1858 ret = cmd_enable_channel(session, domain, attr, wpipe);
1859 if (ret != LTTNG_OK) {
1860 goto error;
1861 }
1862 channel_created = 1;
1863 }
1864
1865 /* Get the newly created kernel channel pointer */
1866 kchan = trace_kernel_get_channel_by_name(channel_name,
1867 session->kernel_session);
1868 if (kchan == NULL) {
1869 /* This sould not happen... */
1870 ret = LTTNG_ERR_FATAL;
1871 goto error;
1872 }
1873
1874 switch (event->type) {
1875 case LTTNG_EVENT_ALL:
1876 {
1877 char *filter_expression_a = NULL;
1878 struct lttng_filter_bytecode *filter_a = NULL;
1879
1880 /*
1881 * We need to duplicate filter_expression and filter,
1882 * because ownership is passed to first enable
1883 * event.
1884 */
1885 if (filter_expression) {
1886 filter_expression_a = strdup(filter_expression);
1887 if (!filter_expression_a) {
1888 ret = LTTNG_ERR_FATAL;
1889 goto error;
1890 }
1891 }
1892 if (filter) {
1893 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
1894 if (!filter_a) {
1895 free(filter_expression_a);
1896 ret = LTTNG_ERR_FATAL;
1897 goto error;
1898 }
1899 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
1900 }
1901 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
1902 ret = event_kernel_enable_event(kchan, event,
1903 filter_expression, filter);
1904 /* We have passed ownership */
1905 filter_expression = NULL;
1906 filter = NULL;
1907 if (ret != LTTNG_OK) {
1908 if (channel_created) {
1909 /* Let's not leak a useless channel. */
1910 kernel_destroy_channel(kchan);
1911 }
1912 free(filter_expression_a);
1913 free(filter_a);
1914 goto error;
1915 }
1916 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
1917 ret = event_kernel_enable_event(kchan, event,
1918 filter_expression_a, filter_a);
1919 /* We have passed ownership */
1920 filter_expression_a = NULL;
1921 filter_a = NULL;
1922 if (ret != LTTNG_OK) {
1923 goto error;
1924 }
1925 break;
1926 }
1927 case LTTNG_EVENT_PROBE:
1928 case LTTNG_EVENT_FUNCTION:
1929 case LTTNG_EVENT_FUNCTION_ENTRY:
1930 case LTTNG_EVENT_TRACEPOINT:
1931 ret = event_kernel_enable_event(kchan, event,
1932 filter_expression, filter);
1933 /* We have passed ownership */
1934 filter_expression = NULL;
1935 filter = NULL;
1936 if (ret != LTTNG_OK) {
1937 if (channel_created) {
1938 /* Let's not leak a useless channel. */
1939 kernel_destroy_channel(kchan);
1940 }
1941 goto error;
1942 }
1943 break;
1944 case LTTNG_EVENT_SYSCALL:
1945 ret = event_kernel_enable_event(kchan, event,
1946 filter_expression, filter);
1947 /* We have passed ownership */
1948 filter_expression = NULL;
1949 filter = NULL;
1950 if (ret != LTTNG_OK) {
1951 goto error;
1952 }
1953 break;
1954 default:
1955 ret = LTTNG_ERR_UNK;
1956 goto error;
1957 }
1958
1959 kernel_wait_quiescent(kernel_tracer_fd);
1960 break;
1961 }
1962 case LTTNG_DOMAIN_UST:
1963 {
1964 struct ltt_ust_channel *uchan;
1965 struct ltt_ust_session *usess = session->ust_session;
1966
1967 assert(usess);
1968
1969 /*
1970 * If a non-default channel has been created in the
1971 * session, explicitely require that -c chan_name needs
1972 * to be provided.
1973 */
1974 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1975 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1976 goto error;
1977 }
1978
1979 /* Get channel from global UST domain */
1980 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1981 channel_name);
1982 if (uchan == NULL) {
1983 /* Create default channel */
1984 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
1985 usess->buffer_type);
1986 if (attr == NULL) {
1987 ret = LTTNG_ERR_FATAL;
1988 goto error;
1989 }
1990 if (lttng_strncpy(attr->name, channel_name,
1991 sizeof(attr->name))) {
1992 ret = LTTNG_ERR_INVALID;
1993 goto error;
1994 }
1995
1996 ret = cmd_enable_channel(session, domain, attr, wpipe);
1997 if (ret != LTTNG_OK) {
1998 goto error;
1999 }
2000
2001 /* Get the newly created channel reference back */
2002 uchan = trace_ust_find_channel_by_name(
2003 usess->domain_global.channels, channel_name);
2004 assert(uchan);
2005 }
2006
2007 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2008 /*
2009 * Don't allow users to add UST events to channels which
2010 * are assigned to a userspace subdomain (JUL, Log4J,
2011 * Python, etc.).
2012 */
2013 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2014 goto error;
2015 }
2016
2017 if (!internal_event) {
2018 /*
2019 * Ensure the event name is not reserved for internal
2020 * use.
2021 */
2022 ret = validate_ust_event_name(event->name);
2023 if (ret) {
2024 WARN("Userspace event name %s failed validation.",
2025 event->name ?
2026 event->name : "NULL");
2027 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2028 goto error;
2029 }
2030 }
2031
2032 /* At this point, the session and channel exist on the tracer */
2033 ret = event_ust_enable_tracepoint(usess, uchan, event,
2034 filter_expression, filter, exclusion,
2035 internal_event);
2036 /* We have passed ownership */
2037 filter_expression = NULL;
2038 filter = NULL;
2039 exclusion = NULL;
2040 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2041 goto already_enabled;
2042 } else if (ret != LTTNG_OK) {
2043 goto error;
2044 }
2045 break;
2046 }
2047 case LTTNG_DOMAIN_LOG4J:
2048 case LTTNG_DOMAIN_JUL:
2049 case LTTNG_DOMAIN_PYTHON:
2050 {
2051 const char *default_event_name, *default_chan_name;
2052 struct agent *agt;
2053 struct lttng_event uevent;
2054 struct lttng_domain tmp_dom;
2055 struct ltt_ust_session *usess = session->ust_session;
2056
2057 assert(usess);
2058
2059 agt = trace_ust_find_agent(usess, domain->type);
2060 if (!agt) {
2061 agt = agent_create(domain->type);
2062 if (!agt) {
2063 ret = LTTNG_ERR_NOMEM;
2064 goto error;
2065 }
2066 agent_add(agt, usess->agents);
2067 }
2068
2069 /* Create the default tracepoint. */
2070 memset(&uevent, 0, sizeof(uevent));
2071 uevent.type = LTTNG_EVENT_TRACEPOINT;
2072 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2073 default_event_name = event_get_default_agent_ust_name(
2074 domain->type);
2075 if (!default_event_name) {
2076 ret = LTTNG_ERR_FATAL;
2077 goto error;
2078 }
2079 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2080 uevent.name[sizeof(uevent.name) - 1] = '\0';
2081
2082 /*
2083 * The domain type is changed because we are about to enable the
2084 * default channel and event for the JUL domain that are hardcoded.
2085 * This happens in the UST domain.
2086 */
2087 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2088 tmp_dom.type = LTTNG_DOMAIN_UST;
2089
2090 switch (domain->type) {
2091 case LTTNG_DOMAIN_LOG4J:
2092 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2093 break;
2094 case LTTNG_DOMAIN_JUL:
2095 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2096 break;
2097 case LTTNG_DOMAIN_PYTHON:
2098 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2099 break;
2100 default:
2101 /* The switch/case we are in makes this impossible */
2102 assert(0);
2103 }
2104
2105 {
2106 char *filter_expression_copy = NULL;
2107 struct lttng_filter_bytecode *filter_copy = NULL;
2108
2109 if (filter) {
2110 const size_t filter_size = sizeof(
2111 struct lttng_filter_bytecode)
2112 + filter->len;
2113
2114 filter_copy = zmalloc(filter_size);
2115 if (!filter_copy) {
2116 ret = LTTNG_ERR_NOMEM;
2117 goto error;
2118 }
2119 memcpy(filter_copy, filter, filter_size);
2120
2121 filter_expression_copy =
2122 strdup(filter_expression);
2123 if (!filter_expression) {
2124 ret = LTTNG_ERR_NOMEM;
2125 }
2126
2127 if (!filter_expression_copy || !filter_copy) {
2128 free(filter_expression_copy);
2129 free(filter_copy);
2130 goto error;
2131 }
2132 }
2133
2134 ret = cmd_enable_event_internal(session, &tmp_dom,
2135 (char *) default_chan_name,
2136 &uevent, filter_expression_copy,
2137 filter_copy, NULL, wpipe);
2138 }
2139
2140 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2141 goto already_enabled;
2142 } else if (ret != LTTNG_OK) {
2143 goto error;
2144 }
2145
2146 /* The wild card * means that everything should be enabled. */
2147 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2148 ret = event_agent_enable_all(usess, agt, event, filter,
2149 filter_expression);
2150 } else {
2151 ret = event_agent_enable(usess, agt, event, filter,
2152 filter_expression);
2153 }
2154 filter = NULL;
2155 filter_expression = NULL;
2156 if (ret != LTTNG_OK) {
2157 goto error;
2158 }
2159
2160 break;
2161 }
2162 default:
2163 ret = LTTNG_ERR_UND;
2164 goto error;
2165 }
2166
2167 ret = LTTNG_OK;
2168
2169 already_enabled:
2170 error:
2171 free(filter_expression);
2172 free(filter);
2173 free(exclusion);
2174 free(attr);
2175 rcu_read_unlock();
2176 return ret;
2177 }
2178
2179 /*
2180 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2181 * We own filter, exclusion, and filter_expression.
2182 */
2183 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2184 char *channel_name, struct lttng_event *event,
2185 char *filter_expression,
2186 struct lttng_filter_bytecode *filter,
2187 struct lttng_event_exclusion *exclusion,
2188 int wpipe)
2189 {
2190 return _cmd_enable_event(session, domain, channel_name, event,
2191 filter_expression, filter, exclusion, wpipe, false);
2192 }
2193
2194 /*
2195 * Enable an event which is internal to LTTng. An internal should
2196 * never be made visible to clients and are immune to checks such as
2197 * reserved names.
2198 */
2199 static int cmd_enable_event_internal(struct ltt_session *session,
2200 struct lttng_domain *domain,
2201 char *channel_name, struct lttng_event *event,
2202 char *filter_expression,
2203 struct lttng_filter_bytecode *filter,
2204 struct lttng_event_exclusion *exclusion,
2205 int wpipe)
2206 {
2207 return _cmd_enable_event(session, domain, channel_name, event,
2208 filter_expression, filter, exclusion, wpipe, true);
2209 }
2210
2211 /*
2212 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2213 */
2214 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2215 struct lttng_event **events)
2216 {
2217 int ret;
2218 ssize_t nb_events = 0;
2219
2220 switch (domain) {
2221 case LTTNG_DOMAIN_KERNEL:
2222 nb_events = kernel_list_events(kernel_tracer_fd, events);
2223 if (nb_events < 0) {
2224 ret = LTTNG_ERR_KERN_LIST_FAIL;
2225 goto error;
2226 }
2227 break;
2228 case LTTNG_DOMAIN_UST:
2229 nb_events = ust_app_list_events(events);
2230 if (nb_events < 0) {
2231 ret = LTTNG_ERR_UST_LIST_FAIL;
2232 goto error;
2233 }
2234 break;
2235 case LTTNG_DOMAIN_LOG4J:
2236 case LTTNG_DOMAIN_JUL:
2237 case LTTNG_DOMAIN_PYTHON:
2238 nb_events = agent_list_events(events, domain);
2239 if (nb_events < 0) {
2240 ret = LTTNG_ERR_UST_LIST_FAIL;
2241 goto error;
2242 }
2243 break;
2244 default:
2245 ret = LTTNG_ERR_UND;
2246 goto error;
2247 }
2248
2249 return nb_events;
2250
2251 error:
2252 /* Return negative value to differentiate return code */
2253 return -ret;
2254 }
2255
2256 /*
2257 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2258 */
2259 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2260 struct lttng_event_field **fields)
2261 {
2262 int ret;
2263 ssize_t nb_fields = 0;
2264
2265 switch (domain) {
2266 case LTTNG_DOMAIN_UST:
2267 nb_fields = ust_app_list_event_fields(fields);
2268 if (nb_fields < 0) {
2269 ret = LTTNG_ERR_UST_LIST_FAIL;
2270 goto error;
2271 }
2272 break;
2273 case LTTNG_DOMAIN_KERNEL:
2274 default: /* fall-through */
2275 ret = LTTNG_ERR_UND;
2276 goto error;
2277 }
2278
2279 return nb_fields;
2280
2281 error:
2282 /* Return negative value to differentiate return code */
2283 return -ret;
2284 }
2285
2286 ssize_t cmd_list_syscalls(struct lttng_event **events)
2287 {
2288 return syscall_table_list(events);
2289 }
2290
2291 /*
2292 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2293 *
2294 * Called with session lock held.
2295 */
2296 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2297 enum lttng_domain_type domain, int32_t **pids)
2298 {
2299 int ret;
2300 ssize_t nr_pids = 0;
2301
2302 switch (domain) {
2303 case LTTNG_DOMAIN_KERNEL:
2304 {
2305 struct ltt_kernel_session *ksess;
2306
2307 ksess = session->kernel_session;
2308 nr_pids = kernel_list_tracker_pids(ksess, pids);
2309 if (nr_pids < 0) {
2310 ret = LTTNG_ERR_KERN_LIST_FAIL;
2311 goto error;
2312 }
2313 break;
2314 }
2315 case LTTNG_DOMAIN_UST:
2316 {
2317 struct ltt_ust_session *usess;
2318
2319 usess = session->ust_session;
2320 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2321 if (nr_pids < 0) {
2322 ret = LTTNG_ERR_UST_LIST_FAIL;
2323 goto error;
2324 }
2325 break;
2326 }
2327 case LTTNG_DOMAIN_LOG4J:
2328 case LTTNG_DOMAIN_JUL:
2329 case LTTNG_DOMAIN_PYTHON:
2330 default:
2331 ret = LTTNG_ERR_UND;
2332 goto error;
2333 }
2334
2335 return nr_pids;
2336
2337 error:
2338 /* Return negative value to differentiate return code */
2339 return -ret;
2340 }
2341
2342 /*
2343 * Command LTTNG_START_TRACE processed by the client thread.
2344 *
2345 * Called with session mutex held.
2346 */
2347 int cmd_start_trace(struct ltt_session *session)
2348 {
2349 int ret;
2350 unsigned long nb_chan = 0;
2351 struct ltt_kernel_session *ksession;
2352 struct ltt_ust_session *usess;
2353
2354 assert(session);
2355
2356 /* Ease our life a bit ;) */
2357 ksession = session->kernel_session;
2358 usess = session->ust_session;
2359
2360 /* Is the session already started? */
2361 if (session->active) {
2362 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2363 goto error;
2364 }
2365
2366 /*
2367 * Starting a session without channel is useless since after that it's not
2368 * possible to enable channel thus inform the client.
2369 */
2370 if (usess && usess->domain_global.channels) {
2371 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2372 }
2373 if (ksession) {
2374 nb_chan += ksession->channel_count;
2375 }
2376 if (!nb_chan) {
2377 ret = LTTNG_ERR_NO_CHANNEL;
2378 goto error;
2379 }
2380
2381 /* Kernel tracing */
2382 if (ksession != NULL) {
2383 ret = start_kernel_session(ksession, kernel_tracer_fd);
2384 if (ret != LTTNG_OK) {
2385 goto error;
2386 }
2387 }
2388
2389 /* Flag session that trace should start automatically */
2390 if (usess) {
2391 /*
2392 * Even though the start trace might fail, flag this session active so
2393 * other application coming in are started by default.
2394 */
2395 usess->active = 1;
2396
2397 ret = ust_app_start_trace_all(usess);
2398 if (ret < 0) {
2399 ret = LTTNG_ERR_UST_START_FAIL;
2400 goto error;
2401 }
2402 }
2403
2404 /* Flag this after a successful start. */
2405 session->has_been_started = 1;
2406 session->active = 1;
2407
2408 ret = LTTNG_OK;
2409
2410 error:
2411 return ret;
2412 }
2413
2414 /*
2415 * Command LTTNG_STOP_TRACE processed by the client thread.
2416 */
2417 int cmd_stop_trace(struct ltt_session *session)
2418 {
2419 int ret;
2420 struct ltt_kernel_channel *kchan;
2421 struct ltt_kernel_session *ksession;
2422 struct ltt_ust_session *usess;
2423
2424 assert(session);
2425
2426 /* Short cut */
2427 ksession = session->kernel_session;
2428 usess = session->ust_session;
2429
2430 /* Session is not active. Skip everythong and inform the client. */
2431 if (!session->active) {
2432 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2433 goto error;
2434 }
2435
2436 /* Kernel tracer */
2437 if (ksession && ksession->active) {
2438 DBG("Stop kernel tracing");
2439
2440 ret = kernel_stop_session(ksession);
2441 if (ret < 0) {
2442 ret = LTTNG_ERR_KERN_STOP_FAIL;
2443 goto error;
2444 }
2445
2446 kernel_wait_quiescent(kernel_tracer_fd);
2447
2448 /* Flush metadata after stopping (if exists) */
2449 if (ksession->metadata_stream_fd >= 0) {
2450 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2451 if (ret < 0) {
2452 ERR("Kernel metadata flush failed");
2453 }
2454 }
2455
2456 /* Flush all buffers after stopping */
2457 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2458 ret = kernel_flush_buffer(kchan);
2459 if (ret < 0) {
2460 ERR("Kernel flush buffer error");
2461 }
2462 }
2463
2464 ksession->active = 0;
2465 }
2466
2467 if (usess && usess->active) {
2468 /*
2469 * Even though the stop trace might fail, flag this session inactive so
2470 * other application coming in are not started by default.
2471 */
2472 usess->active = 0;
2473
2474 ret = ust_app_stop_trace_all(usess);
2475 if (ret < 0) {
2476 ret = LTTNG_ERR_UST_STOP_FAIL;
2477 goto error;
2478 }
2479 }
2480
2481 /* Flag inactive after a successful stop. */
2482 session->active = 0;
2483 ret = LTTNG_OK;
2484
2485 error:
2486 return ret;
2487 }
2488
2489 /*
2490 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2491 */
2492 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2493 struct lttng_uri *uris)
2494 {
2495 int ret, i;
2496 struct ltt_kernel_session *ksess = session->kernel_session;
2497 struct ltt_ust_session *usess = session->ust_session;
2498
2499 assert(session);
2500 assert(uris);
2501 assert(nb_uri > 0);
2502
2503 /* Can't set consumer URI if the session is active. */
2504 if (session->active) {
2505 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2506 goto error;
2507 }
2508
2509 /* Set the "global" consumer URIs */
2510 for (i = 0; i < nb_uri; i++) {
2511 ret = add_uri_to_consumer(session->consumer,
2512 &uris[i], 0, session->name);
2513 if (ret != LTTNG_OK) {
2514 goto error;
2515 }
2516 }
2517
2518 /* Set UST session URIs */
2519 if (session->ust_session) {
2520 for (i = 0; i < nb_uri; i++) {
2521 ret = add_uri_to_consumer(
2522 session->ust_session->consumer,
2523 &uris[i], LTTNG_DOMAIN_UST,
2524 session->name);
2525 if (ret != LTTNG_OK) {
2526 goto error;
2527 }
2528 }
2529 }
2530
2531 /* Set kernel session URIs */
2532 if (session->kernel_session) {
2533 for (i = 0; i < nb_uri; i++) {
2534 ret = add_uri_to_consumer(
2535 session->kernel_session->consumer,
2536 &uris[i], LTTNG_DOMAIN_KERNEL,
2537 session->name);
2538 if (ret != LTTNG_OK) {
2539 goto error;
2540 }
2541 }
2542 }
2543
2544 /*
2545 * Make sure to set the session in output mode after we set URI since a
2546 * session can be created without URL (thus flagged in no output mode).
2547 */
2548 session->output_traces = 1;
2549 if (ksess) {
2550 ksess->output_traces = 1;
2551 }
2552
2553 if (usess) {
2554 usess->output_traces = 1;
2555 }
2556
2557 /* All good! */
2558 ret = LTTNG_OK;
2559
2560 error:
2561 return ret;
2562 }
2563
2564 /*
2565 * Command LTTNG_CREATE_SESSION processed by the client thread.
2566 */
2567 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
2568 size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
2569 {
2570 int ret;
2571 struct ltt_session *session;
2572
2573 assert(name);
2574 assert(creds);
2575
2576 /*
2577 * Verify if the session already exist
2578 *
2579 * XXX: There is no need for the session lock list here since the caller
2580 * (process_client_msg) is holding it. We might want to change that so a
2581 * single command does not lock the entire session list.
2582 */
2583 session = session_find_by_name(name);
2584 if (session != NULL) {
2585 ret = LTTNG_ERR_EXIST_SESS;
2586 goto find_error;
2587 }
2588
2589 /* Create tracing session in the registry */
2590 ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
2591 LTTNG_SOCK_GET_GID_CRED(creds));
2592 if (ret != LTTNG_OK) {
2593 goto session_error;
2594 }
2595
2596 /*
2597 * Get the newly created session pointer back
2598 *
2599 * XXX: There is no need for the session lock list here since the caller
2600 * (process_client_msg) is holding it. We might want to change that so a
2601 * single command does not lock the entire session list.
2602 */
2603 session = session_find_by_name(name);
2604 assert(session);
2605
2606 session->live_timer = live_timer;
2607 /* Create default consumer output for the session not yet created. */
2608 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
2609 if (session->consumer == NULL) {
2610 ret = LTTNG_ERR_FATAL;
2611 goto consumer_error;
2612 }
2613
2614 if (uris) {
2615 ret = cmd_set_consumer_uri(session, nb_uri, uris);
2616 if (ret != LTTNG_OK) {
2617 goto consumer_error;
2618 }
2619 session->output_traces = 1;
2620 } else {
2621 session->output_traces = 0;
2622 DBG2("Session %s created with no output", session->name);
2623 }
2624
2625 session->consumer->enabled = 1;
2626
2627 return LTTNG_OK;
2628
2629 consumer_error:
2630 session_destroy(session);
2631 session_error:
2632 find_error:
2633 return ret;
2634 }
2635
2636 /*
2637 * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
2638 */
2639 int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
2640 size_t nb_uri, lttng_sock_cred *creds)
2641 {
2642 int ret;
2643 struct ltt_session *session;
2644 struct snapshot_output *new_output = NULL;
2645
2646 assert(name);
2647 assert(creds);
2648
2649 /*
2650 * Create session in no output mode with URIs set to NULL. The uris we've
2651 * received are for a default snapshot output if one.
2652 */
2653 ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
2654 if (ret != LTTNG_OK) {
2655 goto error;
2656 }
2657
2658 /* Get the newly created session pointer back. This should NEVER fail. */
2659 session = session_find_by_name(name);
2660 assert(session);
2661
2662 /* Flag session for snapshot mode. */
2663 session->snapshot_mode = 1;
2664
2665 /* Skip snapshot output creation if no URI is given. */
2666 if (nb_uri == 0) {
2667 goto end;
2668 }
2669
2670 new_output = snapshot_output_alloc();
2671 if (!new_output) {
2672 ret = LTTNG_ERR_NOMEM;
2673 goto error_snapshot_alloc;
2674 }
2675
2676 ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
2677 uris, nb_uri, session->consumer, new_output, &session->snapshot);
2678 if (ret < 0) {
2679 if (ret == -ENOMEM) {
2680 ret = LTTNG_ERR_NOMEM;
2681 } else {
2682 ret = LTTNG_ERR_INVALID;
2683 }
2684 goto error_snapshot;
2685 }
2686
2687 rcu_read_lock();
2688 snapshot_add_output(&session->snapshot, new_output);
2689 rcu_read_unlock();
2690
2691 end:
2692 return LTTNG_OK;
2693
2694 error_snapshot:
2695 snapshot_output_destroy(new_output);
2696 error_snapshot_alloc:
2697 session_destroy(session);
2698 error:
2699 return ret;
2700 }
2701
2702 /*
2703 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2704 *
2705 * Called with session lock held.
2706 */
2707 int cmd_destroy_session(struct ltt_session *session, int wpipe)
2708 {
2709 int ret;
2710 struct ltt_ust_session *usess;
2711 struct ltt_kernel_session *ksess;
2712
2713 /* Safety net */
2714 assert(session);
2715
2716 usess = session->ust_session;
2717 ksess = session->kernel_session;
2718
2719 /* Clean kernel session teardown */
2720 kernel_destroy_session(ksess);
2721
2722 /* UST session teardown */
2723 if (usess) {
2724 /* Close any relayd session */
2725 consumer_output_send_destroy_relayd(usess->consumer);
2726
2727 /* Destroy every UST application related to this session. */
2728 ret = ust_app_destroy_trace_all(usess);
2729 if (ret) {
2730 ERR("Error in ust_app_destroy_trace_all");
2731 }
2732
2733 /* Clean up the rest. */
2734 trace_ust_destroy_session(usess);
2735 }
2736
2737 /*
2738 * Must notify the kernel thread here to update it's poll set in order to
2739 * remove the channel(s)' fd just destroyed.
2740 */
2741 ret = notify_thread_pipe(wpipe);
2742 if (ret < 0) {
2743 PERROR("write kernel poll pipe");
2744 }
2745
2746 ret = session_destroy(session);
2747
2748 return ret;
2749 }
2750
2751 /*
2752 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2753 */
2754 int cmd_register_consumer(struct ltt_session *session,
2755 enum lttng_domain_type domain, const char *sock_path,
2756 struct consumer_data *cdata)
2757 {
2758 int ret, sock;
2759 struct consumer_socket *socket = NULL;
2760
2761 assert(session);
2762 assert(cdata);
2763 assert(sock_path);
2764
2765 switch (domain) {
2766 case LTTNG_DOMAIN_KERNEL:
2767 {
2768 struct ltt_kernel_session *ksess = session->kernel_session;
2769
2770 assert(ksess);
2771
2772 /* Can't register a consumer if there is already one */
2773 if (ksess->consumer_fds_sent != 0) {
2774 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
2775 goto error;
2776 }
2777
2778 sock = lttcomm_connect_unix_sock(sock_path);
2779 if (sock < 0) {
2780 ret = LTTNG_ERR_CONNECT_FAIL;
2781 goto error;
2782 }
2783 cdata->cmd_sock = sock;
2784
2785 socket = consumer_allocate_socket(&cdata->cmd_sock);
2786 if (socket == NULL) {
2787 ret = close(sock);
2788 if (ret < 0) {
2789 PERROR("close register consumer");
2790 }
2791 cdata->cmd_sock = -1;
2792 ret = LTTNG_ERR_FATAL;
2793 goto error;
2794 }
2795
2796 socket->lock = zmalloc(sizeof(pthread_mutex_t));
2797 if (socket->lock == NULL) {
2798 PERROR("zmalloc pthread mutex");
2799 ret = LTTNG_ERR_FATAL;
2800 goto error;
2801 }
2802 pthread_mutex_init(socket->lock, NULL);
2803 socket->registered = 1;
2804
2805 rcu_read_lock();
2806 consumer_add_socket(socket, ksess->consumer);
2807 rcu_read_unlock();
2808
2809 pthread_mutex_lock(&cdata->pid_mutex);
2810 cdata->pid = -1;
2811 pthread_mutex_unlock(&cdata->pid_mutex);
2812
2813 break;
2814 }
2815 default:
2816 /* TODO: Userspace tracing */
2817 ret = LTTNG_ERR_UND;
2818 goto error;
2819 }
2820
2821 return LTTNG_OK;
2822
2823 error:
2824 if (socket) {
2825 consumer_destroy_socket(socket);
2826 }
2827 return ret;
2828 }
2829
2830 /*
2831 * Command LTTNG_LIST_DOMAINS processed by the client thread.
2832 */
2833 ssize_t cmd_list_domains(struct ltt_session *session,
2834 struct lttng_domain **domains)
2835 {
2836 int ret, index = 0;
2837 ssize_t nb_dom = 0;
2838 struct agent *agt;
2839 struct lttng_ht_iter iter;
2840
2841 if (session->kernel_session != NULL) {
2842 DBG3("Listing domains found kernel domain");
2843 nb_dom++;
2844 }
2845
2846 if (session->ust_session != NULL) {
2847 DBG3("Listing domains found UST global domain");
2848 nb_dom++;
2849
2850 rcu_read_lock();
2851 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
2852 agt, node.node) {
2853 if (agt->being_used) {
2854 nb_dom++;
2855 }
2856 }
2857 rcu_read_unlock();
2858 }
2859
2860 if (!nb_dom) {
2861 goto end;
2862 }
2863
2864 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
2865 if (*domains == NULL) {
2866 ret = LTTNG_ERR_FATAL;
2867 goto error;
2868 }
2869
2870 if (session->kernel_session != NULL) {
2871 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
2872
2873 /* Kernel session buffer type is always GLOBAL */
2874 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
2875
2876 index++;
2877 }
2878
2879 if (session->ust_session != NULL) {
2880 (*domains)[index].type = LTTNG_DOMAIN_UST;
2881 (*domains)[index].buf_type = session->ust_session->buffer_type;
2882 index++;
2883
2884 rcu_read_lock();
2885 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
2886 agt, node.node) {
2887 if (agt->being_used) {
2888 (*domains)[index].type = agt->domain;
2889 (*domains)[index].buf_type = session->ust_session->buffer_type;
2890 index++;
2891 }
2892 }
2893 rcu_read_unlock();
2894 }
2895 end:
2896 return nb_dom;
2897
2898 error:
2899 /* Return negative value to differentiate return code */
2900 return -ret;
2901 }
2902
2903
2904 /*
2905 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2906 */
2907 ssize_t cmd_list_channels(enum lttng_domain_type domain,
2908 struct ltt_session *session, struct lttng_channel **channels)
2909 {
2910 ssize_t nb_chan = 0, payload_size = 0, ret;
2911
2912 switch (domain) {
2913 case LTTNG_DOMAIN_KERNEL:
2914 if (session->kernel_session != NULL) {
2915 nb_chan = session->kernel_session->channel_count;
2916 }
2917 DBG3("Number of kernel channels %zd", nb_chan);
2918 if (nb_chan <= 0) {
2919 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2920 goto end;
2921 }
2922 break;
2923 case LTTNG_DOMAIN_UST:
2924 if (session->ust_session != NULL) {
2925 rcu_read_lock();
2926 nb_chan = lttng_ht_get_count(
2927 session->ust_session->domain_global.channels);
2928 rcu_read_unlock();
2929 }
2930 DBG3("Number of UST global channels %zd", nb_chan);
2931 if (nb_chan < 0) {
2932 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
2933 goto end;
2934 }
2935 break;
2936 default:
2937 ret = -LTTNG_ERR_UND;
2938 goto end;
2939 }
2940
2941 if (nb_chan > 0) {
2942 const size_t channel_size = sizeof(struct lttng_channel) +
2943 sizeof(struct lttcomm_channel_extended);
2944 struct lttcomm_channel_extended *channel_exts;
2945
2946 payload_size = nb_chan * channel_size;
2947 *channels = zmalloc(payload_size);
2948 if (*channels == NULL) {
2949 ret = -LTTNG_ERR_FATAL;
2950 goto end;
2951 }
2952
2953 channel_exts = ((void *) *channels) +
2954 (nb_chan * sizeof(struct lttng_channel));
2955 list_lttng_channels(domain, session, *channels, channel_exts);
2956 } else {
2957 *channels = NULL;
2958 }
2959
2960 ret = payload_size;
2961 end:
2962 return ret;
2963 }
2964
2965 /*
2966 * Command LTTNG_LIST_EVENTS processed by the client thread.
2967 */
2968 ssize_t cmd_list_events(enum lttng_domain_type domain,
2969 struct ltt_session *session, char *channel_name,
2970 struct lttng_event **events, size_t *total_size)
2971 {
2972 int ret = 0;
2973 ssize_t nb_event = 0;
2974
2975 switch (domain) {
2976 case LTTNG_DOMAIN_KERNEL:
2977 if (session->kernel_session != NULL) {
2978 nb_event = list_lttng_kernel_events(channel_name,
2979 session->kernel_session, events,
2980 total_size);
2981 }
2982 break;
2983 case LTTNG_DOMAIN_UST:
2984 {
2985 if (session->ust_session != NULL) {
2986 nb_event = list_lttng_ust_global_events(channel_name,
2987 &session->ust_session->domain_global, events,
2988 total_size);
2989 }
2990 break;
2991 }
2992 case LTTNG_DOMAIN_LOG4J:
2993 case LTTNG_DOMAIN_JUL:
2994 case LTTNG_DOMAIN_PYTHON:
2995 if (session->ust_session) {
2996 struct lttng_ht_iter iter;
2997 struct agent *agt;
2998
2999 rcu_read_lock();
3000 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3001 &iter.iter, agt, node.node) {
3002 if (agt->domain == domain) {
3003 nb_event = list_lttng_agent_events(
3004 agt, events,
3005 total_size);
3006 break;
3007 }
3008 }
3009 rcu_read_unlock();
3010 }
3011 break;
3012 default:
3013 ret = LTTNG_ERR_UND;
3014 goto error;
3015 }
3016
3017 return nb_event;
3018
3019 error:
3020 /* Return negative value to differentiate return code */
3021 return -ret;
3022 }
3023
3024 /*
3025 * Using the session list, filled a lttng_session array to send back to the
3026 * client for session listing.
3027 *
3028 * The session list lock MUST be acquired before calling this function. Use
3029 * session_lock_list() and session_unlock_list().
3030 */
3031 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
3032 gid_t gid)
3033 {
3034 int ret;
3035 unsigned int i = 0;
3036 struct ltt_session *session;
3037 struct ltt_session_list *list = session_get_list();
3038
3039 DBG("Getting all available session for UID %d GID %d",
3040 uid, gid);
3041 /*
3042 * Iterate over session list and append data after the control struct in
3043 * the buffer.
3044 */
3045 cds_list_for_each_entry(session, &list->head, list) {
3046 /*
3047 * Only list the sessions the user can control.
3048 */
3049 if (!session_access_ok(session, uid, gid)) {
3050 continue;
3051 }
3052
3053 struct ltt_kernel_session *ksess = session->kernel_session;
3054 struct ltt_ust_session *usess = session->ust_session;
3055
3056 if (session->consumer->type == CONSUMER_DST_NET ||
3057 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3058 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3059 ret = build_network_session_path(sessions[i].path,
3060 sizeof(sessions[i].path), session);
3061 } else {
3062 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3063 session->consumer->dst.trace_path);
3064 }
3065 if (ret < 0) {
3066 PERROR("snprintf session path");
3067 continue;
3068 }
3069
3070 strncpy(sessions[i].name, session->name, NAME_MAX);
3071 sessions[i].name[NAME_MAX - 1] = '\0';
3072 sessions[i].enabled = session->active;
3073 sessions[i].snapshot_mode = session->snapshot_mode;
3074 sessions[i].live_timer_interval = session->live_timer;
3075 i++;
3076 }
3077 }
3078
3079 /*
3080 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3081 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3082 */
3083 int cmd_data_pending(struct ltt_session *session)
3084 {
3085 int ret;
3086 struct ltt_kernel_session *ksess = session->kernel_session;
3087 struct ltt_ust_session *usess = session->ust_session;
3088
3089 assert(session);
3090
3091 /* Session MUST be stopped to ask for data availability. */
3092 if (session->active) {
3093 ret = LTTNG_ERR_SESSION_STARTED;
3094 goto error;
3095 } else {
3096 /*
3097 * If stopped, just make sure we've started before else the above call
3098 * will always send that there is data pending.
3099 *
3100 * The consumer assumes that when the data pending command is received,
3101 * the trace has been started before or else no output data is written
3102 * by the streams which is a condition for data pending. So, this is
3103 * *VERY* important that we don't ask the consumer before a start
3104 * trace.
3105 */
3106 if (!session->has_been_started) {
3107 ret = 0;
3108 goto error;
3109 }
3110 }
3111
3112 if (ksess && ksess->consumer) {
3113 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3114 if (ret == 1) {
3115 /* Data is still being extracted for the kernel. */
3116 goto error;
3117 }
3118 }
3119
3120 if (usess && usess->consumer) {
3121 ret = consumer_is_data_pending(usess->id, usess->consumer);
3122 if (ret == 1) {
3123 /* Data is still being extracted for the kernel. */
3124 goto error;
3125 }
3126 }
3127
3128 /* Data is ready to be read by a viewer */
3129 ret = 0;
3130
3131 error:
3132 return ret;
3133 }
3134
3135 /*
3136 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3137 *
3138 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3139 */
3140 int cmd_snapshot_add_output(struct ltt_session *session,
3141 struct lttng_snapshot_output *output, uint32_t *id)
3142 {
3143 int ret;
3144 struct snapshot_output *new_output;
3145
3146 assert(session);
3147 assert(output);
3148
3149 DBG("Cmd snapshot add output for session %s", session->name);
3150
3151 /*
3152 * Can't create an output if the session is not set in no-output mode.
3153 */
3154 if (session->output_traces) {
3155 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3156 goto error;
3157 }
3158
3159 /* Only one output is allowed until we have the "tee" feature. */
3160 if (session->snapshot.nb_output == 1) {
3161 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3162 goto error;
3163 }
3164
3165 new_output = snapshot_output_alloc();
3166 if (!new_output) {
3167 ret = LTTNG_ERR_NOMEM;
3168 goto error;
3169 }
3170
3171 ret = snapshot_output_init(output->max_size, output->name,
3172 output->ctrl_url, output->data_url, session->consumer, new_output,
3173 &session->snapshot);
3174 if (ret < 0) {
3175 if (ret == -ENOMEM) {
3176 ret = LTTNG_ERR_NOMEM;
3177 } else {
3178 ret = LTTNG_ERR_INVALID;
3179 }
3180 goto free_error;
3181 }
3182
3183 rcu_read_lock();
3184 snapshot_add_output(&session->snapshot, new_output);
3185 if (id) {
3186 *id = new_output->id;
3187 }
3188 rcu_read_unlock();
3189
3190 return LTTNG_OK;
3191
3192 free_error:
3193 snapshot_output_destroy(new_output);
3194 error:
3195 return ret;
3196 }
3197
3198 /*
3199 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3200 *
3201 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3202 */
3203 int cmd_snapshot_del_output(struct ltt_session *session,
3204 struct lttng_snapshot_output *output)
3205 {
3206 int ret;
3207 struct snapshot_output *sout = NULL;
3208
3209 assert(session);
3210 assert(output);
3211
3212 rcu_read_lock();
3213
3214 /*
3215 * Permission denied to create an output if the session is not
3216 * set in no output mode.
3217 */
3218 if (session->output_traces) {
3219 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3220 goto error;
3221 }
3222
3223 if (output->id) {
3224 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3225 session->name);
3226 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3227 } else if (*output->name != '\0') {
3228 DBG("Cmd snapshot del output name %s for session %s", output->name,
3229 session->name);
3230 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3231 }
3232 if (!sout) {
3233 ret = LTTNG_ERR_INVALID;
3234 goto error;
3235 }
3236
3237 snapshot_delete_output(&session->snapshot, sout);
3238 snapshot_output_destroy(sout);
3239 ret = LTTNG_OK;
3240
3241 error:
3242 rcu_read_unlock();
3243 return ret;
3244 }
3245
3246 /*
3247 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3248 *
3249 * If no output is available, outputs is untouched and 0 is returned.
3250 *
3251 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3252 */
3253 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3254 struct lttng_snapshot_output **outputs)
3255 {
3256 int ret, idx = 0;
3257 struct lttng_snapshot_output *list = NULL;
3258 struct lttng_ht_iter iter;
3259 struct snapshot_output *output;
3260
3261 assert(session);
3262 assert(outputs);
3263
3264 DBG("Cmd snapshot list outputs for session %s", session->name);
3265
3266 /*
3267 * Permission denied to create an output if the session is not
3268 * set in no output mode.
3269 */
3270 if (session->output_traces) {
3271 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3272 goto end;
3273 }
3274
3275 if (session->snapshot.nb_output == 0) {
3276 ret = 0;
3277 goto end;
3278 }
3279
3280 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3281 if (!list) {
3282 ret = -LTTNG_ERR_NOMEM;
3283 goto end;
3284 }
3285
3286 /* Copy list from session to the new list object. */
3287 rcu_read_lock();
3288 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3289 output, node.node) {
3290 assert(output->consumer);
3291 list[idx].id = output->id;
3292 list[idx].max_size = output->max_size;
3293 if (lttng_strncpy(list[idx].name, output->name,
3294 sizeof(list[idx].name))) {
3295 ret = -LTTNG_ERR_INVALID;
3296 goto error;
3297 }
3298 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3299 if (lttng_strncpy(list[idx].ctrl_url,
3300 output->consumer->dst.trace_path,
3301 sizeof(list[idx].ctrl_url))) {
3302 ret = -LTTNG_ERR_INVALID;
3303 goto error;
3304 }
3305 } else {
3306 /* Control URI. */
3307 ret = uri_to_str_url(&output->consumer->dst.net.control,
3308 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3309 if (ret < 0) {
3310 ret = -LTTNG_ERR_NOMEM;
3311 goto error;
3312 }
3313
3314 /* Data URI. */
3315 ret = uri_to_str_url(&output->consumer->dst.net.data,
3316 list[idx].data_url, sizeof(list[idx].data_url));
3317 if (ret < 0) {
3318 ret = -LTTNG_ERR_NOMEM;
3319 goto error;
3320 }
3321 }
3322 idx++;
3323 }
3324
3325 *outputs = list;
3326 list = NULL;
3327 ret = session->snapshot.nb_output;
3328 error:
3329 rcu_read_unlock();
3330 free(list);
3331 end:
3332 return ret;
3333 }
3334
3335 /*
3336 * Check if we can regenerate the metadata for this session.
3337 * Only kernel, UST per-uid and non-live sessions are supported.
3338 *
3339 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3340 */
3341 static
3342 int check_regenerate_metadata_support(struct ltt_session *session)
3343 {
3344 int ret;
3345
3346 assert(session);
3347
3348 if (session->live_timer != 0) {
3349 ret = LTTNG_ERR_LIVE_SESSION;
3350 goto end;
3351 }
3352 if (!session->active) {
3353 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3354 goto end;
3355 }
3356 if (session->ust_session) {
3357 switch (session->ust_session->buffer_type) {
3358 case LTTNG_BUFFER_PER_UID:
3359 break;
3360 case LTTNG_BUFFER_PER_PID:
3361 ret = LTTNG_ERR_PER_PID_SESSION;
3362 goto end;
3363 default:
3364 assert(0);
3365 ret = LTTNG_ERR_UNK;
3366 goto end;
3367 }
3368 }
3369 if (session->consumer->type == CONSUMER_DST_NET &&
3370 session->consumer->relay_minor_version < 8) {
3371 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
3372 goto end;
3373 }
3374 ret = 0;
3375
3376 end:
3377 return ret;
3378 }
3379
3380 static
3381 int ust_regenerate_metadata(struct ltt_ust_session *usess)
3382 {
3383 int ret = 0;
3384 struct buffer_reg_uid *uid_reg = NULL;
3385 struct buffer_reg_session *session_reg = NULL;
3386
3387 rcu_read_lock();
3388 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
3389 struct ust_registry_session *registry;
3390 struct ust_registry_channel *chan;
3391 struct lttng_ht_iter iter_chan;
3392
3393 session_reg = uid_reg->registry;
3394 registry = session_reg->reg.ust;
3395
3396 pthread_mutex_lock(&registry->lock);
3397 registry->metadata_len_sent = 0;
3398 memset(registry->metadata, 0, registry->metadata_alloc_len);
3399 registry->metadata_len = 0;
3400 registry->metadata_version++;
3401 ret = ust_metadata_session_statedump(registry, NULL,
3402 registry->major, registry->minor);
3403 if (ret) {
3404 pthread_mutex_unlock(&registry->lock);
3405 ERR("Failed to generate session metadata (err = %d)",
3406 ret);
3407 goto end;
3408 }
3409 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
3410 chan, node.node) {
3411 struct ust_registry_event *event;
3412 struct lttng_ht_iter iter_event;
3413
3414 ret = ust_metadata_channel_statedump(registry, chan);
3415 if (ret) {
3416 pthread_mutex_unlock(&registry->lock);
3417 ERR("Failed to generate channel metadata "
3418 "(err = %d)", ret);
3419 goto end;
3420 }
3421 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
3422 event, node.node) {
3423 ret = ust_metadata_event_statedump(registry,
3424 chan, event);
3425 if (ret) {
3426 pthread_mutex_unlock(&registry->lock);
3427 ERR("Failed to generate event metadata "
3428 "(err = %d)", ret);
3429 goto end;
3430 }
3431 }
3432 }
3433 pthread_mutex_unlock(&registry->lock);
3434 }
3435
3436 end:
3437 rcu_read_unlock();
3438 return ret;
3439 }
3440
3441 /*
3442 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
3443 *
3444 * Ask the consumer to truncate the existing metadata file(s) and
3445 * then regenerate the metadata. Live and per-pid sessions are not
3446 * supported and return an error.
3447 *
3448 * Return 0 on success or else a LTTNG_ERR code.
3449 */
3450 int cmd_regenerate_metadata(struct ltt_session *session)
3451 {
3452 int ret;
3453
3454 assert(session);
3455
3456 ret = check_regenerate_metadata_support(session);
3457 if (ret) {
3458 goto end;
3459 }
3460
3461 if (session->kernel_session) {
3462 ret = kernctl_session_regenerate_metadata(
3463 session->kernel_session->fd);
3464 if (ret < 0) {
3465 ERR("Failed to regenerate the kernel metadata");
3466 goto end;
3467 }
3468 }
3469
3470 if (session->ust_session) {
3471 ret = ust_regenerate_metadata(session->ust_session);
3472 if (ret < 0) {
3473 ERR("Failed to regenerate the UST metadata");
3474 goto end;
3475 }
3476 }
3477 DBG("Cmd metadata regenerate for session %s", session->name);
3478 ret = LTTNG_OK;
3479
3480 end:
3481 return ret;
3482 }
3483
3484 /*
3485 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
3486 *
3487 * Ask the tracer to regenerate a new statedump.
3488 *
3489 * Return 0 on success or else a LTTNG_ERR code.
3490 */
3491 int cmd_regenerate_statedump(struct ltt_session *session)
3492 {
3493 int ret;
3494
3495 assert(session);
3496
3497 if (!session->active) {
3498 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3499 goto end;
3500 }
3501 ret = 0;
3502
3503 if (session->kernel_session) {
3504 ret = kernctl_session_regenerate_statedump(
3505 session->kernel_session->fd);
3506 /*
3507 * Currently, the statedump in kernel can only fail if out
3508 * of memory.
3509 */
3510 if (ret < 0) {
3511 if (ret == -ENOMEM) {
3512 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
3513 } else {
3514 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
3515 }
3516 ERR("Failed to regenerate the kernel statedump");
3517 goto end;
3518 }
3519 }
3520
3521 if (session->ust_session) {
3522 ret = ust_app_regenerate_statedump_all(session->ust_session);
3523 /*
3524 * Currently, the statedump in UST always returns 0.
3525 */
3526 if (ret < 0) {
3527 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
3528 ERR("Failed to regenerate the UST statedump");
3529 goto end;
3530 }
3531 }
3532 DBG("Cmd regenerate statedump for session %s", session->name);
3533 ret = LTTNG_OK;
3534
3535 end:
3536 return ret;
3537 }
3538
3539 /*
3540 * Send relayd sockets from snapshot output to consumer. Ignore request if the
3541 * snapshot output is *not* set with a remote destination.
3542 *
3543 * Return 0 on success or a LTTNG_ERR code.
3544 */
3545 static int set_relayd_for_snapshot(struct consumer_output *consumer,
3546 struct snapshot_output *snap_output, struct ltt_session *session)
3547 {
3548 int ret = LTTNG_OK;
3549 struct lttng_ht_iter iter;
3550 struct consumer_socket *socket;
3551
3552 assert(consumer);
3553 assert(snap_output);
3554 assert(session);
3555
3556 DBG2("Set relayd object from snapshot output");
3557
3558 /* Ignore if snapshot consumer output is not network. */
3559 if (snap_output->consumer->type != CONSUMER_DST_NET) {
3560 goto error;
3561 }
3562
3563 /*
3564 * For each consumer socket, create and send the relayd object of the
3565 * snapshot output.
3566 */
3567 rcu_read_lock();
3568 cds_lfht_for_each_entry(snap_output->consumer->socks->ht, &iter.iter,
3569 socket, node.node) {
3570 ret = send_consumer_relayd_sockets(0, session->id,
3571 snap_output->consumer, socket,
3572 session->name, session->hostname,
3573 session->live_timer);
3574 if (ret != LTTNG_OK) {
3575 rcu_read_unlock();
3576 goto error;
3577 }
3578 }
3579 rcu_read_unlock();
3580
3581 error:
3582 return ret;
3583 }
3584
3585 /*
3586 * Record a kernel snapshot.
3587 *
3588 * Return LTTNG_OK on success or a LTTNG_ERR code.
3589 */
3590 static int record_kernel_snapshot(struct ltt_kernel_session *ksess,
3591 struct snapshot_output *output, struct ltt_session *session,
3592 int wait, uint64_t nb_packets_per_stream)
3593 {
3594 int ret;
3595
3596 assert(ksess);
3597 assert(output);
3598 assert(session);
3599
3600
3601 /*
3602 * Copy kernel session sockets so we can communicate with the right
3603 * consumer for the snapshot record command.
3604 */
3605 ret = consumer_copy_sockets(output->consumer, ksess->consumer);
3606 if (ret < 0) {
3607 ret = LTTNG_ERR_NOMEM;
3608 goto error;
3609 }
3610
3611 ret = set_relayd_for_snapshot(ksess->consumer, output, session);
3612 if (ret != LTTNG_OK) {
3613 goto error_snapshot;
3614 }
3615
3616 ret = kernel_snapshot_record(ksess, output, wait, nb_packets_per_stream);
3617 if (ret != LTTNG_OK) {
3618 goto error_snapshot;
3619 }
3620
3621 ret = LTTNG_OK;
3622 goto end;
3623
3624 error_snapshot:
3625 /* Clean up copied sockets so this output can use some other later on. */
3626 consumer_destroy_output_sockets(output->consumer);
3627 error:
3628 end:
3629 return ret;
3630 }
3631
3632 /*
3633 * Record a UST snapshot.
3634 *
3635 * Return 0 on success or a LTTNG_ERR error code.
3636 */
3637 static int record_ust_snapshot(struct ltt_ust_session *usess,
3638 struct snapshot_output *output, struct ltt_session *session,
3639 int wait, uint64_t nb_packets_per_stream)
3640 {
3641 int ret;
3642
3643 assert(usess);
3644 assert(output);
3645 assert(session);
3646
3647 /*
3648 * Copy UST session sockets so we can communicate with the right
3649 * consumer for the snapshot record command.
3650 */
3651 ret = consumer_copy_sockets(output->consumer, usess->consumer);
3652 if (ret < 0) {
3653 ret = LTTNG_ERR_NOMEM;
3654 goto error;
3655 }
3656
3657 ret = set_relayd_for_snapshot(usess->consumer, output, session);
3658 if (ret != LTTNG_OK) {
3659 goto error_snapshot;
3660 }
3661
3662 ret = ust_app_snapshot_record(usess, output, wait, nb_packets_per_stream);
3663 if (ret < 0) {
3664 switch (-ret) {
3665 case EINVAL:
3666 ret = LTTNG_ERR_INVALID;
3667 break;
3668 default:
3669 ret = LTTNG_ERR_SNAPSHOT_FAIL;
3670 break;
3671 }
3672 goto error_snapshot;
3673 }
3674
3675 ret = LTTNG_OK;
3676
3677 error_snapshot:
3678 /* Clean up copied sockets so this output can use some other later on. */
3679 consumer_destroy_output_sockets(output->consumer);
3680 error:
3681 return ret;
3682 }
3683
3684 static
3685 uint64_t get_session_size_one_more_packet_per_stream(struct ltt_session *session,
3686 uint64_t cur_nr_packets)
3687 {
3688 uint64_t tot_size = 0;
3689
3690 if (session->kernel_session) {
3691 struct ltt_kernel_channel *chan;
3692 struct ltt_kernel_session *ksess = session->kernel_session;
3693
3694 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
3695 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
3696 /*
3697 * Don't take channel into account if we
3698 * already grab all its packets.
3699 */
3700 continue;
3701 }
3702 tot_size += chan->channel->attr.subbuf_size
3703 * chan->stream_count;
3704 }
3705 }
3706
3707 if (session->ust_session) {
3708 struct ltt_ust_session *usess = session->ust_session;
3709
3710 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
3711 cur_nr_packets);
3712 }
3713
3714 return tot_size;
3715 }
3716
3717 /*
3718 * Calculate the number of packets we can grab from each stream that
3719 * fits within the overall snapshot max size.
3720 *
3721 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
3722 * the number of packets per stream.
3723 *
3724 * TODO: this approach is not perfect: we consider the worse case
3725 * (packet filling the sub-buffers) as an upper bound, but we could do
3726 * better if we do this calculation while we actually grab the packet
3727 * content: we would know how much padding we don't actually store into
3728 * the file.
3729 *
3730 * This algorithm is currently bounded by the number of packets per
3731 * stream.
3732 *
3733 * Since we call this algorithm before actually grabbing the data, it's
3734 * an approximation: for instance, applications could appear/disappear
3735 * in between this call and actually grabbing data.
3736 */
3737 static
3738 int64_t get_session_nb_packets_per_stream(struct ltt_session *session, uint64_t max_size)
3739 {
3740 int64_t size_left;
3741 uint64_t cur_nb_packets = 0;
3742
3743 if (!max_size) {
3744 return 0; /* Infinite */
3745 }
3746
3747 size_left = max_size;
3748 for (;;) {
3749 uint64_t one_more_packet_tot_size;
3750
3751 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(session,
3752 cur_nb_packets);
3753 if (!one_more_packet_tot_size) {
3754 /* We are already grabbing all packets. */
3755 break;
3756 }
3757 size_left -= one_more_packet_tot_size;
3758 if (size_left < 0) {
3759 break;
3760 }
3761 cur_nb_packets++;
3762 }
3763 if (!cur_nb_packets) {
3764 /* Not enough room to grab one packet of each stream, error. */
3765 return -1;
3766 }
3767 return cur_nb_packets;
3768 }
3769
3770 /*
3771 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
3772 *
3773 * The wait parameter is ignored so this call always wait for the snapshot to
3774 * complete before returning.
3775 *
3776 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3777 */
3778 int cmd_snapshot_record(struct ltt_session *session,
3779 struct lttng_snapshot_output *output, int wait)
3780 {
3781 int ret = LTTNG_OK;
3782 unsigned int use_tmp_output = 0;
3783 struct snapshot_output tmp_output;
3784 unsigned int snapshot_success = 0;
3785 char datetime[16];
3786
3787 assert(session);
3788 assert(output);
3789
3790 DBG("Cmd snapshot record for session %s", session->name);
3791
3792 /* Get the datetime for the snapshot output directory. */
3793 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
3794 sizeof(datetime));
3795 if (!ret) {
3796 ret = LTTNG_ERR_INVALID;
3797 goto error;
3798 }
3799
3800 /*
3801 * Permission denied to create an output if the session is not
3802 * set in no output mode.
3803 */
3804 if (session->output_traces) {
3805 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3806 goto error;
3807 }
3808
3809 /* The session needs to be started at least once. */
3810 if (!session->has_been_started) {
3811 ret = LTTNG_ERR_START_SESSION_ONCE;
3812 goto error;
3813 }