1739aa736f41737dfcd56c183ccca434f890f75f
[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 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
281 channels[i].attr.overwrite = uchan->attr.overwrite;
282 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
283 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
284 channels[i].attr.switch_timer_interval =
285 uchan->attr.switch_timer_interval;
286 channels[i].attr.read_timer_interval =
287 uchan->attr.read_timer_interval;
288 channels[i].enabled = uchan->enabled;
289 channels[i].attr.tracefile_size = uchan->tracefile_size;
290 channels[i].attr.tracefile_count = uchan->tracefile_count;
291
292 /*
293 * Map enum lttng_ust_output to enum lttng_event_output.
294 */
295 switch (uchan->attr.output) {
296 case LTTNG_UST_MMAP:
297 channels[i].attr.output = LTTNG_EVENT_MMAP;
298 break;
299 default:
300 /*
301 * LTTNG_UST_MMAP is the only supported UST
302 * output mode.
303 */
304 assert(0);
305 break;
306 }
307
308 ret = get_ust_runtime_stats(session, uchan,
309 &discarded_events, &lost_packets);
310 if (ret < 0) {
311 break;
312 }
313 chan_exts[i].discarded_events = discarded_events;
314 chan_exts[i].lost_packets = lost_packets;
315 i++;
316 }
317 rcu_read_unlock();
318 break;
319 }
320 default:
321 break;
322 }
323
324 end:
325 return;
326 }
327
328 static void increment_extended_len(const char *filter_expression,
329 struct lttng_event_exclusion *exclusion, size_t *extended_len)
330 {
331 *extended_len += sizeof(struct lttcomm_event_extended_header);
332
333 if (filter_expression) {
334 *extended_len += strlen(filter_expression) + 1;
335 }
336
337 if (exclusion) {
338 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
339 }
340 }
341
342 static void append_extended_info(const char *filter_expression,
343 struct lttng_event_exclusion *exclusion, void **extended_at)
344 {
345 struct lttcomm_event_extended_header extended_header;
346 size_t filter_len = 0;
347 size_t nb_exclusions = 0;
348
349 if (filter_expression) {
350 filter_len = strlen(filter_expression) + 1;
351 }
352
353 if (exclusion) {
354 nb_exclusions = exclusion->count;
355 }
356
357 /* Set header fields */
358 extended_header.filter_len = filter_len;
359 extended_header.nb_exclusions = nb_exclusions;
360
361 /* Copy header */
362 memcpy(*extended_at, &extended_header, sizeof(extended_header));
363 *extended_at += sizeof(extended_header);
364
365 /* Copy filter string */
366 if (filter_expression) {
367 memcpy(*extended_at, filter_expression, filter_len);
368 *extended_at += filter_len;
369 }
370
371 /* Copy exclusion names */
372 if (exclusion) {
373 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
374
375 memcpy(*extended_at, &exclusion->names, len);
376 *extended_at += len;
377 }
378 }
379
380 /*
381 * Create a list of agent domain events.
382 *
383 * Return number of events in list on success or else a negative value.
384 */
385 static int list_lttng_agent_events(struct agent *agt,
386 struct lttng_event **events, size_t *total_size)
387 {
388 int i = 0, ret = 0;
389 unsigned int nb_event = 0;
390 struct agent_event *event;
391 struct lttng_event *tmp_events;
392 struct lttng_ht_iter iter;
393 size_t extended_len = 0;
394 void *extended_at;
395
396 assert(agt);
397 assert(events);
398
399 DBG3("Listing agent events");
400
401 rcu_read_lock();
402 nb_event = lttng_ht_get_count(agt->events);
403 rcu_read_unlock();
404 if (nb_event == 0) {
405 ret = nb_event;
406 *total_size = 0;
407 goto error;
408 }
409
410 /* Compute required extended infos size */
411 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
412
413 /*
414 * This is only valid because the commands which add events are
415 * processed in the same thread as the listing.
416 */
417 rcu_read_lock();
418 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
419 increment_extended_len(event->filter_expression, NULL,
420 &extended_len);
421 }
422 rcu_read_unlock();
423
424 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
425 tmp_events = zmalloc(*total_size);
426 if (!tmp_events) {
427 PERROR("zmalloc agent events session");
428 ret = -LTTNG_ERR_FATAL;
429 goto error;
430 }
431
432 extended_at = ((uint8_t *) tmp_events) +
433 nb_event * sizeof(struct lttng_event);
434
435 rcu_read_lock();
436 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
437 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
438 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
439 tmp_events[i].enabled = event->enabled;
440 tmp_events[i].loglevel = event->loglevel_value;
441 tmp_events[i].loglevel_type = event->loglevel_type;
442 i++;
443
444 /* Append extended info */
445 append_extended_info(event->filter_expression, NULL,
446 &extended_at);
447 }
448 rcu_read_unlock();
449
450 *events = tmp_events;
451 ret = nb_event;
452
453 error:
454 assert(nb_event == i);
455 return ret;
456 }
457
458 /*
459 * Create a list of ust global domain events.
460 */
461 static int list_lttng_ust_global_events(char *channel_name,
462 struct ltt_ust_domain_global *ust_global,
463 struct lttng_event **events, size_t *total_size)
464 {
465 int i = 0, ret = 0;
466 unsigned int nb_event = 0;
467 struct lttng_ht_iter iter;
468 struct lttng_ht_node_str *node;
469 struct ltt_ust_channel *uchan;
470 struct ltt_ust_event *uevent;
471 struct lttng_event *tmp;
472 size_t extended_len = 0;
473 void *extended_at;
474
475 DBG("Listing UST global events for channel %s", channel_name);
476
477 rcu_read_lock();
478
479 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
480 node = lttng_ht_iter_get_node_str(&iter);
481 if (node == NULL) {
482 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
483 goto end;
484 }
485
486 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
487
488 nb_event = lttng_ht_get_count(uchan->events);
489 if (nb_event == 0) {
490 ret = nb_event;
491 *total_size = 0;
492 goto end;
493 }
494
495 DBG3("Listing UST global %d events", nb_event);
496
497 /* Compute required extended infos size */
498 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
499 if (uevent->internal) {
500 nb_event--;
501 continue;
502 }
503
504 increment_extended_len(uevent->filter_expression,
505 uevent->exclusion, &extended_len);
506 }
507 if (nb_event == 0) {
508 /* All events are internal, skip. */
509 ret = 0;
510 *total_size = 0;
511 goto end;
512 }
513
514 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
515 tmp = zmalloc(*total_size);
516 if (tmp == NULL) {
517 ret = -LTTNG_ERR_FATAL;
518 goto end;
519 }
520
521 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
522
523 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
524 if (uevent->internal) {
525 /* This event should remain hidden from clients */
526 continue;
527 }
528 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
529 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
530 tmp[i].enabled = uevent->enabled;
531
532 switch (uevent->attr.instrumentation) {
533 case LTTNG_UST_TRACEPOINT:
534 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
535 break;
536 case LTTNG_UST_PROBE:
537 tmp[i].type = LTTNG_EVENT_PROBE;
538 break;
539 case LTTNG_UST_FUNCTION:
540 tmp[i].type = LTTNG_EVENT_FUNCTION;
541 break;
542 }
543
544 tmp[i].loglevel = uevent->attr.loglevel;
545 switch (uevent->attr.loglevel_type) {
546 case LTTNG_UST_LOGLEVEL_ALL:
547 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
548 break;
549 case LTTNG_UST_LOGLEVEL_RANGE:
550 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
551 break;
552 case LTTNG_UST_LOGLEVEL_SINGLE:
553 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
554 break;
555 }
556 if (uevent->filter) {
557 tmp[i].filter = 1;
558 }
559 if (uevent->exclusion) {
560 tmp[i].exclusion = 1;
561 }
562 i++;
563
564 /* Append extended info */
565 append_extended_info(uevent->filter_expression,
566 uevent->exclusion, &extended_at);
567 }
568
569 ret = nb_event;
570 *events = tmp;
571 end:
572 rcu_read_unlock();
573 return ret;
574 }
575
576 /*
577 * Fill lttng_event array of all kernel events in the channel.
578 */
579 static int list_lttng_kernel_events(char *channel_name,
580 struct ltt_kernel_session *kernel_session,
581 struct lttng_event **events, size_t *total_size)
582 {
583 int i = 0, ret;
584 unsigned int nb_event;
585 struct ltt_kernel_event *event;
586 struct ltt_kernel_channel *kchan;
587 size_t extended_len = 0;
588 void *extended_at;
589
590 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
591 if (kchan == NULL) {
592 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
593 goto error;
594 }
595
596 nb_event = kchan->event_count;
597
598 DBG("Listing events for channel %s", kchan->channel->name);
599
600 if (nb_event == 0) {
601 *total_size = 0;
602 *events = NULL;
603 goto end;
604 }
605
606 /* Compute required extended infos size */
607 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
608 increment_extended_len(event->filter_expression, NULL,
609 &extended_len);
610 }
611
612 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
613 *events = zmalloc(*total_size);
614 if (*events == NULL) {
615 ret = LTTNG_ERR_FATAL;
616 goto error;
617 }
618
619 extended_at = ((void *) *events) +
620 nb_event * sizeof(struct lttng_event);
621
622 /* Kernel channels */
623 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
624 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
625 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
626 (*events)[i].enabled = event->enabled;
627 (*events)[i].filter =
628 (unsigned char) !!event->filter_expression;
629
630 switch (event->event->instrumentation) {
631 case LTTNG_KERNEL_TRACEPOINT:
632 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
633 break;
634 case LTTNG_KERNEL_KRETPROBE:
635 (*events)[i].type = LTTNG_EVENT_FUNCTION;
636 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
637 sizeof(struct lttng_kernel_kprobe));
638 break;
639 case LTTNG_KERNEL_KPROBE:
640 (*events)[i].type = LTTNG_EVENT_PROBE;
641 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
642 sizeof(struct lttng_kernel_kprobe));
643 break;
644 case LTTNG_KERNEL_FUNCTION:
645 (*events)[i].type = LTTNG_EVENT_FUNCTION;
646 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
647 sizeof(struct lttng_kernel_function));
648 break;
649 case LTTNG_KERNEL_NOOP:
650 (*events)[i].type = LTTNG_EVENT_NOOP;
651 break;
652 case LTTNG_KERNEL_SYSCALL:
653 (*events)[i].type = LTTNG_EVENT_SYSCALL;
654 break;
655 case LTTNG_KERNEL_ALL:
656 assert(0);
657 break;
658 }
659 i++;
660
661 /* Append extended info */
662 append_extended_info(event->filter_expression, NULL,
663 &extended_at);
664 }
665
666 end:
667 return nb_event;
668
669 error:
670 /* Negate the error code to differentiate the size from an error */
671 return -ret;
672 }
673
674 /*
675 * Add URI so the consumer output object. Set the correct path depending on the
676 * domain adding the default trace directory.
677 */
678 static int add_uri_to_consumer(struct consumer_output *consumer,
679 struct lttng_uri *uri, enum lttng_domain_type domain,
680 const char *session_name)
681 {
682 int ret = LTTNG_OK;
683 const char *default_trace_dir;
684
685 assert(uri);
686
687 if (consumer == NULL) {
688 DBG("No consumer detected. Don't add URI. Stopping.");
689 ret = LTTNG_ERR_NO_CONSUMER;
690 goto error;
691 }
692
693 switch (domain) {
694 case LTTNG_DOMAIN_KERNEL:
695 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
696 break;
697 case LTTNG_DOMAIN_UST:
698 default_trace_dir = DEFAULT_UST_TRACE_DIR;
699 break;
700 default:
701 /*
702 * This case is possible is we try to add the URI to the global tracing
703 * session consumer object which in this case there is no subdir.
704 */
705 default_trace_dir = "";
706 }
707
708 switch (uri->dtype) {
709 case LTTNG_DST_IPV4:
710 case LTTNG_DST_IPV6:
711 DBG2("Setting network URI to consumer");
712
713 if (consumer->type == CONSUMER_DST_NET) {
714 if ((uri->stype == LTTNG_STREAM_CONTROL &&
715 consumer->dst.net.control_isset) ||
716 (uri->stype == LTTNG_STREAM_DATA &&
717 consumer->dst.net.data_isset)) {
718 ret = LTTNG_ERR_URL_EXIST;
719 goto error;
720 }
721 } else {
722 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
723 }
724
725 consumer->type = CONSUMER_DST_NET;
726
727 /* Set URI into consumer output object */
728 ret = consumer_set_network_uri(consumer, uri);
729 if (ret < 0) {
730 ret = -ret;
731 goto error;
732 } else if (ret == 1) {
733 /*
734 * URI was the same in the consumer so we do not append the subdir
735 * again so to not duplicate output dir.
736 */
737 ret = LTTNG_OK;
738 goto error;
739 }
740
741 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
742 ret = consumer_set_subdir(consumer, session_name);
743 if (ret < 0) {
744 ret = LTTNG_ERR_FATAL;
745 goto error;
746 }
747 }
748
749 if (uri->stype == LTTNG_STREAM_CONTROL) {
750 /* On a new subdir, reappend the default trace dir. */
751 strncat(consumer->subdir, default_trace_dir,
752 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
753 DBG3("Append domain trace name to subdir %s", consumer->subdir);
754 }
755
756 break;
757 case LTTNG_DST_PATH:
758 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
759 memset(consumer->dst.trace_path, 0,
760 sizeof(consumer->dst.trace_path));
761 strncpy(consumer->dst.trace_path, uri->dst.path,
762 sizeof(consumer->dst.trace_path));
763 /* Append default trace dir */
764 strncat(consumer->dst.trace_path, default_trace_dir,
765 sizeof(consumer->dst.trace_path) -
766 strlen(consumer->dst.trace_path) - 1);
767 /* Flag consumer as local. */
768 consumer->type = CONSUMER_DST_LOCAL;
769 break;
770 }
771
772 ret = LTTNG_OK;
773
774 error:
775 return ret;
776 }
777
778 /*
779 * Init tracing by creating trace directory and sending fds kernel consumer.
780 */
781 static int init_kernel_tracing(struct ltt_kernel_session *session)
782 {
783 int ret = 0;
784 struct lttng_ht_iter iter;
785 struct consumer_socket *socket;
786
787 assert(session);
788
789 rcu_read_lock();
790
791 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
792 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
793 socket, node.node) {
794 pthread_mutex_lock(socket->lock);
795 ret = kernel_consumer_send_session(socket, session);
796 pthread_mutex_unlock(socket->lock);
797 if (ret < 0) {
798 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
799 goto error;
800 }
801 }
802 }
803
804 error:
805 rcu_read_unlock();
806 return ret;
807 }
808
809 /*
810 * Create a socket to the relayd using the URI.
811 *
812 * On success, the relayd_sock pointer is set to the created socket.
813 * Else, it's stays untouched and a lttcomm error code is returned.
814 */
815 static int create_connect_relayd(struct lttng_uri *uri,
816 struct lttcomm_relayd_sock **relayd_sock,
817 struct consumer_output *consumer)
818 {
819 int ret;
820 struct lttcomm_relayd_sock *rsock;
821
822 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
823 RELAYD_VERSION_COMM_MINOR);
824 if (!rsock) {
825 ret = LTTNG_ERR_FATAL;
826 goto error;
827 }
828
829 /*
830 * Connect to relayd so we can proceed with a session creation. This call
831 * can possibly block for an arbitrary amount of time to set the health
832 * state to be in poll execution.
833 */
834 health_poll_entry();
835 ret = relayd_connect(rsock);
836 health_poll_exit();
837 if (ret < 0) {
838 ERR("Unable to reach lttng-relayd");
839 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
840 goto free_sock;
841 }
842
843 /* Create socket for control stream. */
844 if (uri->stype == LTTNG_STREAM_CONTROL) {
845 DBG3("Creating relayd stream socket from URI");
846
847 /* Check relayd version */
848 ret = relayd_version_check(rsock);
849 if (ret < 0) {
850 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
851 goto close_sock;
852 }
853 consumer->relay_major_version = rsock->major;
854 consumer->relay_minor_version = rsock->minor;
855 } else if (uri->stype == LTTNG_STREAM_DATA) {
856 DBG3("Creating relayd data socket from URI");
857 } else {
858 /* Command is not valid */
859 ERR("Relayd invalid stream type: %d", uri->stype);
860 ret = LTTNG_ERR_INVALID;
861 goto close_sock;
862 }
863
864 *relayd_sock = rsock;
865
866 return LTTNG_OK;
867
868 close_sock:
869 /* The returned value is not useful since we are on an error path. */
870 (void) relayd_close(rsock);
871 free_sock:
872 free(rsock);
873 error:
874 return ret;
875 }
876
877 /*
878 * Connect to the relayd using URI and send the socket to the right consumer.
879 */
880 static int send_consumer_relayd_socket(enum lttng_domain_type domain,
881 unsigned int session_id, struct lttng_uri *relayd_uri,
882 struct consumer_output *consumer,
883 struct consumer_socket *consumer_sock,
884 char *session_name, char *hostname, int session_live_timer)
885 {
886 int ret;
887 struct lttcomm_relayd_sock *rsock = NULL;
888
889 /* Connect to relayd and make version check if uri is the control. */
890 ret = create_connect_relayd(relayd_uri, &rsock, consumer);
891 if (ret != LTTNG_OK) {
892 goto error;
893 }
894 assert(rsock);
895
896 /* Set the network sequence index if not set. */
897 if (consumer->net_seq_index == (uint64_t) -1ULL) {
898 pthread_mutex_lock(&relayd_net_seq_idx_lock);
899 /*
900 * Increment net_seq_idx because we are about to transfer the
901 * new relayd socket to the consumer.
902 * Assign unique key so the consumer can match streams.
903 */
904 consumer->net_seq_index = ++relayd_net_seq_idx;
905 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
906 }
907
908 /* Send relayd socket to consumer. */
909 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
910 relayd_uri->stype, session_id,
911 session_name, hostname, session_live_timer);
912 if (ret < 0) {
913 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
914 goto close_sock;
915 }
916
917 /* Flag that the corresponding socket was sent. */
918 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
919 consumer_sock->control_sock_sent = 1;
920 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
921 consumer_sock->data_sock_sent = 1;
922 }
923
924 ret = LTTNG_OK;
925
926 /*
927 * Close socket which was dup on the consumer side. The session daemon does
928 * NOT keep track of the relayd socket(s) once transfer to the consumer.
929 */
930
931 close_sock:
932 (void) relayd_close(rsock);
933 free(rsock);
934
935 error:
936 if (ret != LTTNG_OK) {
937 /*
938 * The consumer output for this session should not be used anymore
939 * since the relayd connection failed thus making any tracing or/and
940 * streaming not usable.
941 */
942 consumer->enabled = 0;
943 }
944 return ret;
945 }
946
947 /*
948 * Send both relayd sockets to a specific consumer and domain. This is a
949 * helper function to facilitate sending the information to the consumer for a
950 * session.
951 */
952 static int send_consumer_relayd_sockets(enum lttng_domain_type domain,
953 unsigned int session_id, struct consumer_output *consumer,
954 struct consumer_socket *sock, char *session_name,
955 char *hostname, int session_live_timer)
956 {
957 int ret = LTTNG_OK;
958
959 assert(consumer);
960 assert(sock);
961
962 /* Sending control relayd socket. */
963 if (!sock->control_sock_sent) {
964 ret = send_consumer_relayd_socket(domain, session_id,
965 &consumer->dst.net.control, consumer, sock,
966 session_name, hostname, session_live_timer);
967 if (ret != LTTNG_OK) {
968 goto error;
969 }
970 }
971
972 /* Sending data relayd socket. */
973 if (!sock->data_sock_sent) {
974 ret = send_consumer_relayd_socket(domain, session_id,
975 &consumer->dst.net.data, consumer, sock,
976 session_name, hostname, session_live_timer);
977 if (ret != LTTNG_OK) {
978 goto error;
979 }
980 }
981
982 error:
983 return ret;
984 }
985
986 /*
987 * Setup relayd connections for a tracing session. First creates the socket to
988 * the relayd and send them to the right domain consumer. Consumer type MUST be
989 * network.
990 */
991 int cmd_setup_relayd(struct ltt_session *session)
992 {
993 int ret = LTTNG_OK;
994 struct ltt_ust_session *usess;
995 struct ltt_kernel_session *ksess;
996 struct consumer_socket *socket;
997 struct lttng_ht_iter iter;
998
999 assert(session);
1000
1001 usess = session->ust_session;
1002 ksess = session->kernel_session;
1003
1004 DBG("Setting relayd for session %s", session->name);
1005
1006 rcu_read_lock();
1007
1008 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1009 && usess->consumer->enabled) {
1010 /* For each consumer socket, send relayd sockets */
1011 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1012 socket, node.node) {
1013 pthread_mutex_lock(socket->lock);
1014 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1015 usess->consumer, socket,
1016 session->name, session->hostname,
1017 session->live_timer);
1018 pthread_mutex_unlock(socket->lock);
1019 if (ret != LTTNG_OK) {
1020 goto error;
1021 }
1022 /* Session is now ready for network streaming. */
1023 session->net_handle = 1;
1024 }
1025 session->consumer->relay_major_version =
1026 usess->consumer->relay_major_version;
1027 session->consumer->relay_minor_version =
1028 usess->consumer->relay_minor_version;
1029 }
1030
1031 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1032 && ksess->consumer->enabled) {
1033 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1034 socket, node.node) {
1035 pthread_mutex_lock(socket->lock);
1036 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1037 ksess->consumer, socket,
1038 session->name, session->hostname,
1039 session->live_timer);
1040 pthread_mutex_unlock(socket->lock);
1041 if (ret != LTTNG_OK) {
1042 goto error;
1043 }
1044 /* Session is now ready for network streaming. */
1045 session->net_handle = 1;
1046 }
1047 session->consumer->relay_major_version =
1048 ksess->consumer->relay_major_version;
1049 session->consumer->relay_minor_version =
1050 ksess->consumer->relay_minor_version;
1051 }
1052
1053 error:
1054 rcu_read_unlock();
1055 return ret;
1056 }
1057
1058 /*
1059 * Start a kernel session by opening all necessary streams.
1060 */
1061 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1062 {
1063 int ret;
1064 struct ltt_kernel_channel *kchan;
1065
1066 /* Open kernel metadata */
1067 if (ksess->metadata == NULL && ksess->output_traces) {
1068 ret = kernel_open_metadata(ksess);
1069 if (ret < 0) {
1070 ret = LTTNG_ERR_KERN_META_FAIL;
1071 goto error;
1072 }
1073 }
1074
1075 /* Open kernel metadata stream */
1076 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1077 ret = kernel_open_metadata_stream(ksess);
1078 if (ret < 0) {
1079 ERR("Kernel create metadata stream failed");
1080 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1081 goto error;
1082 }
1083 }
1084
1085 /* For each channel */
1086 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1087 if (kchan->stream_count == 0) {
1088 ret = kernel_open_channel_stream(kchan);
1089 if (ret < 0) {
1090 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1091 goto error;
1092 }
1093 /* Update the stream global counter */
1094 ksess->stream_count_global += ret;
1095 }
1096 }
1097
1098 /* Setup kernel consumer socket and send fds to it */
1099 ret = init_kernel_tracing(ksess);
1100 if (ret != 0) {
1101 ret = LTTNG_ERR_KERN_START_FAIL;
1102 goto error;
1103 }
1104
1105 /* This start the kernel tracing */
1106 ret = kernel_start_session(ksess);
1107 if (ret < 0) {
1108 ret = LTTNG_ERR_KERN_START_FAIL;
1109 goto error;
1110 }
1111
1112 /* Quiescent wait after starting trace */
1113 kernel_wait_quiescent(kernel_tracer_fd);
1114
1115 ksess->active = 1;
1116
1117 ret = LTTNG_OK;
1118
1119 error:
1120 return ret;
1121 }
1122
1123 /*
1124 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1125 */
1126 int cmd_disable_channel(struct ltt_session *session,
1127 enum lttng_domain_type domain, char *channel_name)
1128 {
1129 int ret;
1130 struct ltt_ust_session *usess;
1131
1132 usess = session->ust_session;
1133
1134 rcu_read_lock();
1135
1136 switch (domain) {
1137 case LTTNG_DOMAIN_KERNEL:
1138 {
1139 ret = channel_kernel_disable(session->kernel_session,
1140 channel_name);
1141 if (ret != LTTNG_OK) {
1142 goto error;
1143 }
1144
1145 kernel_wait_quiescent(kernel_tracer_fd);
1146 break;
1147 }
1148 case LTTNG_DOMAIN_UST:
1149 {
1150 struct ltt_ust_channel *uchan;
1151 struct lttng_ht *chan_ht;
1152
1153 chan_ht = usess->domain_global.channels;
1154
1155 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1156 if (uchan == NULL) {
1157 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1158 goto error;
1159 }
1160
1161 ret = channel_ust_disable(usess, uchan);
1162 if (ret != LTTNG_OK) {
1163 goto error;
1164 }
1165 break;
1166 }
1167 default:
1168 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1169 goto error;
1170 }
1171
1172 ret = LTTNG_OK;
1173
1174 error:
1175 rcu_read_unlock();
1176 return ret;
1177 }
1178
1179 /*
1180 * Command LTTNG_TRACK_PID processed by the client thread.
1181 *
1182 * Called with session lock held.
1183 */
1184 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1185 int pid)
1186 {
1187 int ret;
1188
1189 rcu_read_lock();
1190
1191 switch (domain) {
1192 case LTTNG_DOMAIN_KERNEL:
1193 {
1194 struct ltt_kernel_session *ksess;
1195
1196 ksess = session->kernel_session;
1197
1198 ret = kernel_track_pid(ksess, pid);
1199 if (ret != LTTNG_OK) {
1200 goto error;
1201 }
1202
1203 kernel_wait_quiescent(kernel_tracer_fd);
1204 break;
1205 }
1206 case LTTNG_DOMAIN_UST:
1207 {
1208 struct ltt_ust_session *usess;
1209
1210 usess = session->ust_session;
1211
1212 ret = trace_ust_track_pid(usess, pid);
1213 if (ret != LTTNG_OK) {
1214 goto error;
1215 }
1216 break;
1217 }
1218 default:
1219 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1220 goto error;
1221 }
1222
1223 ret = LTTNG_OK;
1224
1225 error:
1226 rcu_read_unlock();
1227 return ret;
1228 }
1229
1230 /*
1231 * Command LTTNG_UNTRACK_PID processed by the client thread.
1232 *
1233 * Called with session lock held.
1234 */
1235 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1236 int pid)
1237 {
1238 int ret;
1239
1240 rcu_read_lock();
1241
1242 switch (domain) {
1243 case LTTNG_DOMAIN_KERNEL:
1244 {
1245 struct ltt_kernel_session *ksess;
1246
1247 ksess = session->kernel_session;
1248
1249 ret = kernel_untrack_pid(ksess, pid);
1250 if (ret != LTTNG_OK) {
1251 goto error;
1252 }
1253
1254 kernel_wait_quiescent(kernel_tracer_fd);
1255 break;
1256 }
1257 case LTTNG_DOMAIN_UST:
1258 {
1259 struct ltt_ust_session *usess;
1260
1261 usess = session->ust_session;
1262
1263 ret = trace_ust_untrack_pid(usess, pid);
1264 if (ret != LTTNG_OK) {
1265 goto error;
1266 }
1267 break;
1268 }
1269 default:
1270 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1271 goto error;
1272 }
1273
1274 ret = LTTNG_OK;
1275
1276 error:
1277 rcu_read_unlock();
1278 return ret;
1279 }
1280
1281 /*
1282 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1283 *
1284 * The wpipe arguments is used as a notifier for the kernel thread.
1285 */
1286 int cmd_enable_channel(struct ltt_session *session,
1287 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1288 {
1289 int ret;
1290 struct ltt_ust_session *usess = session->ust_session;
1291 struct lttng_ht *chan_ht;
1292 size_t len;
1293
1294 assert(session);
1295 assert(attr);
1296 assert(domain);
1297
1298 len = lttng_strnlen(attr->name, sizeof(attr->name));
1299
1300 /* Validate channel name */
1301 if (attr->name[0] == '.' ||
1302 memchr(attr->name, '/', len) != NULL) {
1303 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1304 goto end;
1305 }
1306
1307 DBG("Enabling channel %s for session %s", attr->name, session->name);
1308
1309 rcu_read_lock();
1310
1311 /*
1312 * Don't try to enable a channel if the session has been started at
1313 * some point in time before. The tracer does not allow it.
1314 */
1315 if (session->has_been_started) {
1316 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1317 goto error;
1318 }
1319
1320 /*
1321 * If the session is a live session, remove the switch timer, the
1322 * live timer does the same thing but sends also synchronisation
1323 * beacons for inactive streams.
1324 */
1325 if (session->live_timer > 0) {
1326 attr->attr.live_timer_interval = session->live_timer;
1327 attr->attr.switch_timer_interval = 0;
1328 }
1329
1330 /*
1331 * The ringbuffer (both in user space and kernel) behave badly in overwrite
1332 * mode and with less than 2 subbuf so block it right away and send back an
1333 * invalid attribute error.
1334 */
1335 if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
1336 ret = LTTNG_ERR_INVALID;
1337 goto error;
1338 }
1339
1340 switch (domain->type) {
1341 case LTTNG_DOMAIN_KERNEL:
1342 {
1343 struct ltt_kernel_channel *kchan;
1344
1345 kchan = trace_kernel_get_channel_by_name(attr->name,
1346 session->kernel_session);
1347 if (kchan == NULL) {
1348 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1349 if (attr->name[0] != '\0') {
1350 session->kernel_session->has_non_default_channel = 1;
1351 }
1352 } else {
1353 ret = channel_kernel_enable(session->kernel_session, kchan);
1354 }
1355
1356 if (ret != LTTNG_OK) {
1357 goto error;
1358 }
1359
1360 kernel_wait_quiescent(kernel_tracer_fd);
1361 break;
1362 }
1363 case LTTNG_DOMAIN_UST:
1364 case LTTNG_DOMAIN_JUL:
1365 case LTTNG_DOMAIN_LOG4J:
1366 case LTTNG_DOMAIN_PYTHON:
1367 {
1368 struct ltt_ust_channel *uchan;
1369
1370 /*
1371 * FIXME
1372 *
1373 * Current agent implementation limitations force us to allow
1374 * only one channel at once in "agent" subdomains. Each
1375 * subdomain has a default channel name which must be strictly
1376 * adhered to.
1377 */
1378 if (domain->type == LTTNG_DOMAIN_JUL) {
1379 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1380 LTTNG_SYMBOL_NAME_LEN)) {
1381 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1382 goto error;
1383 }
1384 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1385 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1386 LTTNG_SYMBOL_NAME_LEN)) {
1387 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1388 goto error;
1389 }
1390 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1391 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1392 LTTNG_SYMBOL_NAME_LEN)) {
1393 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1394 goto error;
1395 }
1396 }
1397
1398 chan_ht = usess->domain_global.channels;
1399
1400 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1401 if (uchan == NULL) {
1402 ret = channel_ust_create(usess, attr, domain->buf_type);
1403 if (attr->name[0] != '\0') {
1404 usess->has_non_default_channel = 1;
1405 }
1406 } else {
1407 ret = channel_ust_enable(usess, uchan);
1408 }
1409 break;
1410 }
1411 default:
1412 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1413 goto error;
1414 }
1415
1416 error:
1417 rcu_read_unlock();
1418 end:
1419 return ret;
1420 }
1421
1422 /*
1423 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1424 */
1425 int cmd_disable_event(struct ltt_session *session,
1426 enum lttng_domain_type domain, char *channel_name,
1427 struct lttng_event *event)
1428 {
1429 int ret;
1430 char *event_name;
1431
1432 DBG("Disable event command for event \'%s\'", event->name);
1433
1434 event_name = event->name;
1435 if (validate_event_name(event_name)) {
1436 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1437 goto error;
1438 }
1439
1440 /* Error out on unhandled search criteria */
1441 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1442 || event->pid || event->filter || event->exclusion) {
1443 ret = LTTNG_ERR_UNK;
1444 goto error;
1445 }
1446
1447 rcu_read_lock();
1448
1449 switch (domain) {
1450 case LTTNG_DOMAIN_KERNEL:
1451 {
1452 struct ltt_kernel_channel *kchan;
1453 struct ltt_kernel_session *ksess;
1454
1455 ksess = session->kernel_session;
1456
1457 /*
1458 * If a non-default channel has been created in the
1459 * session, explicitely require that -c chan_name needs
1460 * to be provided.
1461 */
1462 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1463 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1464 goto error_unlock;
1465 }
1466
1467 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1468 if (kchan == NULL) {
1469 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1470 goto error_unlock;
1471 }
1472
1473 switch (event->type) {
1474 case LTTNG_EVENT_ALL:
1475 case LTTNG_EVENT_TRACEPOINT:
1476 case LTTNG_EVENT_SYSCALL:
1477 case LTTNG_EVENT_PROBE:
1478 case LTTNG_EVENT_FUNCTION:
1479 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1480 if (event_name[0] == '\0') {
1481 ret = event_kernel_disable_event(kchan,
1482 NULL, event->type);
1483 } else {
1484 ret = event_kernel_disable_event(kchan,
1485 event_name, event->type);
1486 }
1487 if (ret != LTTNG_OK) {
1488 goto error_unlock;
1489 }
1490 break;
1491 default:
1492 ret = LTTNG_ERR_UNK;
1493 goto error_unlock;
1494 }
1495
1496 kernel_wait_quiescent(kernel_tracer_fd);
1497 break;
1498 }
1499 case LTTNG_DOMAIN_UST:
1500 {
1501 struct ltt_ust_channel *uchan;
1502 struct ltt_ust_session *usess;
1503
1504 usess = session->ust_session;
1505
1506 if (validate_ust_event_name(event_name)) {
1507 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1508 goto error_unlock;
1509 }
1510
1511 /*
1512 * If a non-default channel has been created in the
1513 * session, explicitly require that -c chan_name needs
1514 * to be provided.
1515 */
1516 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1517 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1518 goto error_unlock;
1519 }
1520
1521 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1522 channel_name);
1523 if (uchan == NULL) {
1524 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1525 goto error_unlock;
1526 }
1527
1528 switch (event->type) {
1529 case LTTNG_EVENT_ALL:
1530 /*
1531 * An empty event name means that everything
1532 * should be disabled.
1533 */
1534 if (event->name[0] == '\0') {
1535 ret = event_ust_disable_all_tracepoints(usess, uchan);
1536 } else {
1537 ret = event_ust_disable_tracepoint(usess, uchan,
1538 event_name);
1539 }
1540 if (ret != LTTNG_OK) {
1541 goto error_unlock;
1542 }
1543 break;
1544 default:
1545 ret = LTTNG_ERR_UNK;
1546 goto error_unlock;
1547 }
1548
1549 DBG3("Disable UST event %s in channel %s completed", event_name,
1550 channel_name);
1551 break;
1552 }
1553 case LTTNG_DOMAIN_LOG4J:
1554 case LTTNG_DOMAIN_JUL:
1555 case LTTNG_DOMAIN_PYTHON:
1556 {
1557 struct agent *agt;
1558 struct ltt_ust_session *usess = session->ust_session;
1559
1560 assert(usess);
1561
1562 switch (event->type) {
1563 case LTTNG_EVENT_ALL:
1564 break;
1565 default:
1566 ret = LTTNG_ERR_UNK;
1567 goto error_unlock;
1568 }
1569
1570 agt = trace_ust_find_agent(usess, domain);
1571 if (!agt) {
1572 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1573 goto error_unlock;
1574 }
1575 /*
1576 * An empty event name means that everything
1577 * should be disabled.
1578 */
1579 if (event->name[0] == '\0') {
1580 ret = event_agent_disable_all(usess, agt);
1581 } else {
1582 ret = event_agent_disable(usess, agt, event_name);
1583 }
1584 if (ret != LTTNG_OK) {
1585 goto error_unlock;
1586 }
1587
1588 break;
1589 }
1590 default:
1591 ret = LTTNG_ERR_UND;
1592 goto error_unlock;
1593 }
1594
1595 ret = LTTNG_OK;
1596
1597 error_unlock:
1598 rcu_read_unlock();
1599 error:
1600 return ret;
1601 }
1602
1603 /*
1604 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1605 */
1606 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1607 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1608 {
1609 int ret, chan_kern_created = 0, chan_ust_created = 0;
1610 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1611
1612 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1613 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1614 app_ctx_name = ctx->u.app_ctx.ctx_name;
1615 }
1616
1617 switch (domain) {
1618 case LTTNG_DOMAIN_KERNEL:
1619 assert(session->kernel_session);
1620
1621 if (session->kernel_session->channel_count == 0) {
1622 /* Create default channel */
1623 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1624 if (ret != LTTNG_OK) {
1625 goto error;
1626 }
1627 chan_kern_created = 1;
1628 }
1629 /* Add kernel context to kernel tracer */
1630 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1631 if (ret != LTTNG_OK) {
1632 goto error;
1633 }
1634 break;
1635 case LTTNG_DOMAIN_JUL:
1636 case LTTNG_DOMAIN_LOG4J:
1637 {
1638 /*
1639 * Validate channel name.
1640 * If no channel name is given and the domain is JUL or LOG4J,
1641 * set it to the appropriate domain-specific channel name. If
1642 * a name is provided but does not match the expexted channel
1643 * name, return an error.
1644 */
1645 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1646 strcmp(channel_name,
1647 DEFAULT_JUL_CHANNEL_NAME)) {
1648 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1649 goto error;
1650 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1651 strcmp(channel_name,
1652 DEFAULT_LOG4J_CHANNEL_NAME)) {
1653 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1654 goto error;
1655 }
1656 /* break is _not_ missing here. */
1657 }
1658 case LTTNG_DOMAIN_UST:
1659 {
1660 struct ltt_ust_session *usess = session->ust_session;
1661 unsigned int chan_count;
1662
1663 assert(usess);
1664
1665 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1666 if (chan_count == 0) {
1667 struct lttng_channel *attr;
1668 /* Create default channel */
1669 attr = channel_new_default_attr(domain, usess->buffer_type);
1670 if (attr == NULL) {
1671 ret = LTTNG_ERR_FATAL;
1672 goto error;
1673 }
1674
1675 ret = channel_ust_create(usess, attr, usess->buffer_type);
1676 if (ret != LTTNG_OK) {
1677 free(attr);
1678 goto error;
1679 }
1680 free(attr);
1681 chan_ust_created = 1;
1682 }
1683
1684 ret = context_ust_add(usess, domain, ctx, channel_name);
1685 free(app_ctx_provider_name);
1686 free(app_ctx_name);
1687 app_ctx_name = NULL;
1688 app_ctx_provider_name = NULL;
1689 if (ret != LTTNG_OK) {
1690 goto error;
1691 }
1692 break;
1693 }
1694 default:
1695 ret = LTTNG_ERR_UND;
1696 goto error;
1697 }
1698
1699 ret = LTTNG_OK;
1700 goto end;
1701
1702 error:
1703 if (chan_kern_created) {
1704 struct ltt_kernel_channel *kchan =
1705 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1706 session->kernel_session);
1707 /* Created previously, this should NOT fail. */
1708 assert(kchan);
1709 kernel_destroy_channel(kchan);
1710 }
1711
1712 if (chan_ust_created) {
1713 struct ltt_ust_channel *uchan =
1714 trace_ust_find_channel_by_name(
1715 session->ust_session->domain_global.channels,
1716 DEFAULT_CHANNEL_NAME);
1717 /* Created previously, this should NOT fail. */
1718 assert(uchan);
1719 /* Remove from the channel list of the session. */
1720 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1721 uchan);
1722 trace_ust_destroy_channel(uchan);
1723 }
1724 end:
1725 free(app_ctx_provider_name);
1726 free(app_ctx_name);
1727 return ret;
1728 }
1729
1730 static int validate_event_name(const char *name)
1731 {
1732 int ret = 0;
1733 const char *c = name;
1734 const char *event_name_end = c + LTTNG_SYMBOL_NAME_LEN;
1735 bool null_terminated = false;
1736
1737 /*
1738 * Make sure that unescaped wildcards are only used as the last
1739 * character of the event name.
1740 */
1741 while (c < event_name_end) {
1742 switch (*c) {
1743 case '\0':
1744 null_terminated = true;
1745 goto end;
1746 case '\\':
1747 c++;
1748 break;
1749 case '*':
1750 if ((c + 1) < event_name_end && *(c + 1)) {
1751 /* Wildcard is not the last character */
1752 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1753 goto end;
1754 }
1755 default:
1756 break;
1757 }
1758 c++;
1759 }
1760 end:
1761 if (!ret && !null_terminated) {
1762 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1763 }
1764 return ret;
1765 }
1766
1767 static inline bool name_starts_with(const char *name, const char *prefix)
1768 {
1769 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1770
1771 return !strncmp(name, prefix, max_cmp_len);
1772 }
1773
1774 /* Perform userspace-specific event name validation */
1775 static int validate_ust_event_name(const char *name)
1776 {
1777 int ret = 0;
1778
1779 if (!name) {
1780 ret = -1;
1781 goto end;
1782 }
1783
1784 /*
1785 * Check name against all internal UST event component namespaces used
1786 * by the agents.
1787 */
1788 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1789 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1790 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1791 ret = -1;
1792 }
1793
1794 end:
1795 return ret;
1796 }
1797
1798 /*
1799 * Internal version of cmd_enable_event() with a supplemental
1800 * "internal_event" flag which is used to enable internal events which should
1801 * be hidden from clients. Such events are used in the agent implementation to
1802 * enable the events through which all "agent" events are funeled.
1803 */
1804 static int _cmd_enable_event(struct ltt_session *session,
1805 struct lttng_domain *domain,
1806 char *channel_name, struct lttng_event *event,
1807 char *filter_expression,
1808 struct lttng_filter_bytecode *filter,
1809 struct lttng_event_exclusion *exclusion,
1810 int wpipe, bool internal_event)
1811 {
1812 int ret, channel_created = 0;
1813 struct lttng_channel *attr;
1814
1815 assert(session);
1816 assert(event);
1817 assert(channel_name);
1818
1819 /* If we have a filter, we must have its filter expression */
1820 assert(!(!!filter_expression ^ !!filter));
1821
1822 DBG("Enable event command for event \'%s\'", event->name);
1823
1824 rcu_read_lock();
1825
1826 ret = validate_event_name(event->name);
1827 if (ret) {
1828 goto error;
1829 }
1830
1831 switch (domain->type) {
1832 case LTTNG_DOMAIN_KERNEL:
1833 {
1834 struct ltt_kernel_channel *kchan;
1835
1836 /*
1837 * If a non-default channel has been created in the
1838 * session, explicitely require that -c chan_name needs
1839 * to be provided.
1840 */
1841 if (session->kernel_session->has_non_default_channel
1842 && channel_name[0] == '\0') {
1843 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1844 goto error;
1845 }
1846
1847 kchan = trace_kernel_get_channel_by_name(channel_name,
1848 session->kernel_session);
1849 if (kchan == NULL) {
1850 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
1851 LTTNG_BUFFER_GLOBAL);
1852 if (attr == NULL) {
1853 ret = LTTNG_ERR_FATAL;
1854 goto error;
1855 }
1856 strncpy(attr->name, channel_name, sizeof(attr->name));
1857
1858 ret = cmd_enable_channel(session, domain, attr, wpipe);
1859 if (ret != LTTNG_OK) {
1860 free(attr);
1861 goto error;
1862 }
1863 free(attr);
1864
1865 channel_created = 1;
1866 }
1867
1868 /* Get the newly created kernel channel pointer */
1869 kchan = trace_kernel_get_channel_by_name(channel_name,
1870 session->kernel_session);
1871 if (kchan == NULL) {
1872 /* This sould not happen... */
1873 ret = LTTNG_ERR_FATAL;
1874 goto error;
1875 }
1876
1877 switch (event->type) {
1878 case LTTNG_EVENT_ALL:
1879 {
1880 char *filter_expression_a = NULL;
1881 struct lttng_filter_bytecode *filter_a = NULL;
1882
1883 /*
1884 * We need to duplicate filter_expression and filter,
1885 * because ownership is passed to first enable
1886 * event.
1887 */
1888 if (filter_expression) {
1889 filter_expression_a = strdup(filter_expression);
1890 if (!filter_expression_a) {
1891 ret = LTTNG_ERR_FATAL;
1892 goto error;
1893 }
1894 }
1895 if (filter) {
1896 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
1897 if (!filter_a) {
1898 free(filter_expression_a);
1899 ret = LTTNG_ERR_FATAL;
1900 goto error;
1901 }
1902 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
1903 }
1904 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
1905 ret = event_kernel_enable_event(kchan, event,
1906 filter_expression, filter);
1907 /* We have passed ownership */
1908 filter_expression = NULL;
1909 filter = NULL;
1910 if (ret != LTTNG_OK) {
1911 if (channel_created) {
1912 /* Let's not leak a useless channel. */
1913 kernel_destroy_channel(kchan);
1914 }
1915 free(filter_expression_a);
1916 free(filter_a);
1917 goto error;
1918 }
1919 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
1920 ret = event_kernel_enable_event(kchan, event,
1921 filter_expression_a, filter_a);
1922 /* We have passed ownership */
1923 filter_expression_a = NULL;
1924 filter_a = NULL;
1925 if (ret != LTTNG_OK) {
1926 goto error;
1927 }
1928 break;
1929 }
1930 case LTTNG_EVENT_PROBE:
1931 case LTTNG_EVENT_FUNCTION:
1932 case LTTNG_EVENT_FUNCTION_ENTRY:
1933 case LTTNG_EVENT_TRACEPOINT:
1934 ret = event_kernel_enable_event(kchan, event,
1935 filter_expression, filter);
1936 /* We have passed ownership */
1937 filter_expression = NULL;
1938 filter = NULL;
1939 if (ret != LTTNG_OK) {
1940 if (channel_created) {
1941 /* Let's not leak a useless channel. */
1942 kernel_destroy_channel(kchan);
1943 }
1944 goto error;
1945 }
1946 break;
1947 case LTTNG_EVENT_SYSCALL:
1948 ret = event_kernel_enable_event(kchan, event,
1949 filter_expression, filter);
1950 /* We have passed ownership */
1951 filter_expression = NULL;
1952 filter = NULL;
1953 if (ret != LTTNG_OK) {
1954 goto error;
1955 }
1956 break;
1957 default:
1958 ret = LTTNG_ERR_UNK;
1959 goto error;
1960 }
1961
1962 kernel_wait_quiescent(kernel_tracer_fd);
1963 break;
1964 }
1965 case LTTNG_DOMAIN_UST:
1966 {
1967 struct ltt_ust_channel *uchan;
1968 struct ltt_ust_session *usess = session->ust_session;
1969
1970 assert(usess);
1971
1972 /*
1973 * If a non-default channel has been created in the
1974 * session, explicitely require that -c chan_name needs
1975 * to be provided.
1976 */
1977 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1978 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1979 goto error;
1980 }
1981
1982 /* Get channel from global UST domain */
1983 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1984 channel_name);
1985 if (uchan == NULL) {
1986 /* Create default channel */
1987 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
1988 usess->buffer_type);
1989 if (attr == NULL) {
1990 ret = LTTNG_ERR_FATAL;
1991 goto error;
1992 }
1993 strncpy(attr->name, channel_name, sizeof(attr->name));
1994
1995 ret = cmd_enable_channel(session, domain, attr, wpipe);
1996 if (ret != LTTNG_OK) {
1997 free(attr);
1998 goto error;
1999 }
2000 free(attr);
2001
2002 /* Get the newly created channel reference back */
2003 uchan = trace_ust_find_channel_by_name(
2004 usess->domain_global.channels, channel_name);
2005 assert(uchan);
2006 }
2007
2008 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2009 /*
2010 * Don't allow users to add UST events to channels which
2011 * are assigned to a userspace subdomain (JUL, Log4J,
2012 * Python, etc.).
2013 */
2014 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2015 goto error;
2016 }
2017
2018 if (!internal_event) {
2019 /*
2020 * Ensure the event name is not reserved for internal
2021 * use.
2022 */
2023 ret = validate_ust_event_name(event->name);
2024 if (ret) {
2025 WARN("Userspace event name %s failed validation.",
2026 event->name ?
2027 event->name : "NULL");
2028 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2029 goto error;
2030 }
2031 }
2032
2033 /* At this point, the session and channel exist on the tracer */
2034 ret = event_ust_enable_tracepoint(usess, uchan, event,
2035 filter_expression, filter, exclusion,
2036 internal_event);
2037 /* We have passed ownership */
2038 filter_expression = NULL;
2039 filter = NULL;
2040 exclusion = NULL;
2041 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2042 goto already_enabled;
2043 } else if (ret != LTTNG_OK) {
2044 goto error;
2045 }
2046 break;
2047 }
2048 case LTTNG_DOMAIN_LOG4J:
2049 case LTTNG_DOMAIN_JUL:
2050 case LTTNG_DOMAIN_PYTHON:
2051 {
2052 const char *default_event_name, *default_chan_name;
2053 struct agent *agt;
2054 struct lttng_event uevent;
2055 struct lttng_domain tmp_dom;
2056 struct ltt_ust_session *usess = session->ust_session;
2057
2058 assert(usess);
2059
2060 agt = trace_ust_find_agent(usess, domain->type);
2061 if (!agt) {
2062 agt = agent_create(domain->type);
2063 if (!agt) {
2064 ret = LTTNG_ERR_NOMEM;
2065 goto error;
2066 }
2067 agent_add(agt, usess->agents);
2068 }
2069
2070 /* Create the default tracepoint. */
2071 memset(&uevent, 0, sizeof(uevent));
2072 uevent.type = LTTNG_EVENT_TRACEPOINT;
2073 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2074 default_event_name = event_get_default_agent_ust_name(
2075 domain->type);
2076 if (!default_event_name) {
2077 ret = LTTNG_ERR_FATAL;
2078 goto error;
2079 }
2080 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2081 uevent.name[sizeof(uevent.name) - 1] = '\0';
2082
2083 /*
2084 * The domain type is changed because we are about to enable the
2085 * default channel and event for the JUL domain that are hardcoded.
2086 * This happens in the UST domain.
2087 */
2088 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2089 tmp_dom.type = LTTNG_DOMAIN_UST;
2090
2091 switch (domain->type) {
2092 case LTTNG_DOMAIN_LOG4J:
2093 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2094 break;
2095 case LTTNG_DOMAIN_JUL:
2096 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2097 break;
2098 case LTTNG_DOMAIN_PYTHON:
2099 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2100 break;
2101 default:
2102 /* The switch/case we are in makes this impossible */
2103 assert(0);
2104 }
2105
2106 {
2107 char *filter_expression_copy = NULL;
2108 struct lttng_filter_bytecode *filter_copy = NULL;
2109
2110 if (filter) {
2111 const size_t filter_size = sizeof(
2112 struct lttng_filter_bytecode)
2113 + filter->len;
2114
2115 filter_copy = zmalloc(filter_size);
2116 if (!filter_copy) {
2117 ret = LTTNG_ERR_NOMEM;
2118 goto error;
2119 }
2120 memcpy(filter_copy, filter, filter_size);
2121
2122 filter_expression_copy =
2123 strdup(filter_expression);
2124 if (!filter_expression) {
2125 ret = LTTNG_ERR_NOMEM;
2126 }
2127
2128 if (!filter_expression_copy || !filter_copy) {
2129 free(filter_expression_copy);
2130 free(filter_copy);
2131 goto error;
2132 }
2133 }
2134
2135 ret = cmd_enable_event_internal(session, &tmp_dom,
2136 (char *) default_chan_name,
2137 &uevent, filter_expression_copy,
2138 filter_copy, NULL, wpipe);
2139 }
2140
2141 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2142 goto already_enabled;
2143 } else if (ret != LTTNG_OK) {
2144 goto error;
2145 }
2146
2147 /* The wild card * means that everything should be enabled. */
2148 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2149 ret = event_agent_enable_all(usess, agt, event, filter,
2150 filter_expression);
2151 } else {
2152 ret = event_agent_enable(usess, agt, event, filter,
2153 filter_expression);
2154 }
2155 filter = NULL;
2156 filter_expression = NULL;
2157 if (ret != LTTNG_OK) {
2158 goto error;
2159 }
2160
2161 break;
2162 }
2163 default:
2164 ret = LTTNG_ERR_UND;
2165 goto error;
2166 }
2167
2168 ret = LTTNG_OK;
2169
2170 already_enabled:
2171 error:
2172 free(filter_expression);
2173 free(filter);
2174 free(exclusion);
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 /* Flush metadata if exist */
2441 if (ksession->metadata_stream_fd >= 0) {
2442 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2443 if (ret < 0) {
2444 ERR("Kernel metadata flush failed");
2445 }
2446 }
2447
2448 /* Flush all buffers before stopping */
2449 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2450 ret = kernel_flush_buffer(kchan);
2451 if (ret < 0) {
2452 ERR("Kernel flush buffer error");
2453 }
2454 }
2455
2456 ret = kernel_stop_session(ksession);
2457 if (ret < 0) {
2458 ret = LTTNG_ERR_KERN_STOP_FAIL;
2459 goto error;
2460 }
2461
2462 kernel_wait_quiescent(kernel_tracer_fd);
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_CALIBRATE processed by the client thread.
2753 */
2754 int cmd_calibrate(enum lttng_domain_type domain,
2755 struct lttng_calibrate *calibrate)
2756 {
2757 int ret;
2758
2759 switch (domain) {
2760 case LTTNG_DOMAIN_KERNEL:
2761 {
2762 struct lttng_kernel_calibrate kcalibrate;
2763
2764 switch (calibrate->type) {
2765 case LTTNG_CALIBRATE_FUNCTION:
2766 default:
2767 /* Default and only possible calibrate option. */
2768 kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
2769 break;
2770 }
2771
2772 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2773 if (ret < 0) {
2774 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
2775 goto error;
2776 }
2777 break;
2778 }
2779 case LTTNG_DOMAIN_UST:
2780 {
2781 struct lttng_ust_calibrate ucalibrate;
2782
2783 switch (calibrate->type) {
2784 case LTTNG_CALIBRATE_FUNCTION:
2785 default:
2786 /* Default and only possible calibrate option. */
2787 ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
2788 break;
2789 }
2790
2791 ret = ust_app_calibrate_glb(&ucalibrate);
2792 if (ret < 0) {
2793 ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
2794 goto error;
2795 }
2796 break;
2797 }
2798 default:
2799 ret = LTTNG_ERR_UND;
2800 goto error;
2801 }
2802
2803 ret = LTTNG_OK;
2804
2805 error:
2806 return ret;
2807 }
2808
2809 /*
2810 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2811 */
2812 int cmd_register_consumer(struct ltt_session *session,
2813 enum lttng_domain_type domain, const char *sock_path,
2814 struct consumer_data *cdata)
2815 {
2816 int ret, sock;
2817 struct consumer_socket *socket = NULL;
2818
2819 assert(session);
2820 assert(cdata);
2821 assert(sock_path);
2822
2823 switch (domain) {
2824 case LTTNG_DOMAIN_KERNEL:
2825 {
2826 struct ltt_kernel_session *ksess = session->kernel_session;
2827
2828 assert(ksess);
2829
2830 /* Can't register a consumer if there is already one */
2831 if (ksess->consumer_fds_sent != 0) {
2832 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
2833 goto error;
2834 }
2835
2836 sock = lttcomm_connect_unix_sock(sock_path);
2837 if (sock < 0) {
2838 ret = LTTNG_ERR_CONNECT_FAIL;
2839 goto error;
2840 }
2841 cdata->cmd_sock = sock;
2842
2843 socket = consumer_allocate_socket(&cdata->cmd_sock);
2844 if (socket == NULL) {
2845 ret = close(sock);
2846 if (ret < 0) {
2847 PERROR("close register consumer");
2848 }
2849 cdata->cmd_sock = -1;
2850 ret = LTTNG_ERR_FATAL;
2851 goto error;
2852 }
2853
2854 socket->lock = zmalloc(sizeof(pthread_mutex_t));
2855 if (socket->lock == NULL) {
2856 PERROR("zmalloc pthread mutex");
2857 ret = LTTNG_ERR_FATAL;
2858 goto error;
2859 }
2860 pthread_mutex_init(socket->lock, NULL);
2861 socket->registered = 1;
2862
2863 rcu_read_lock();
2864 consumer_add_socket(socket, ksess->consumer);
2865 rcu_read_unlock();
2866
2867 pthread_mutex_lock(&cdata->pid_mutex);
2868 cdata->pid = -1;
2869 pthread_mutex_unlock(&cdata->pid_mutex);
2870
2871 break;
2872 }
2873 default:
2874 /* TODO: Userspace tracing */
2875 ret = LTTNG_ERR_UND;
2876 goto error;
2877 }
2878
2879 return LTTNG_OK;
2880
2881 error:
2882 if (socket) {
2883 consumer_destroy_socket(socket);
2884 }
2885 return ret;
2886 }
2887
2888 /*
2889 * Command LTTNG_LIST_DOMAINS processed by the client thread.
2890 */
2891 ssize_t cmd_list_domains(struct ltt_session *session,
2892 struct lttng_domain **domains)
2893 {
2894 int ret, index = 0;
2895 ssize_t nb_dom = 0;
2896 struct agent *agt;
2897 struct lttng_ht_iter iter;
2898
2899 if (session->kernel_session != NULL) {
2900 DBG3("Listing domains found kernel domain");
2901 nb_dom++;
2902 }
2903
2904 if (session->ust_session != NULL) {
2905 DBG3("Listing domains found UST global domain");
2906 nb_dom++;
2907
2908 rcu_read_lock();
2909 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
2910 agt, node.node) {
2911 if (agt->being_used) {
2912 nb_dom++;
2913 }
2914 }
2915 rcu_read_unlock();
2916 }
2917
2918 if (!nb_dom) {
2919 goto end;
2920 }
2921
2922 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
2923 if (*domains == NULL) {
2924 ret = LTTNG_ERR_FATAL;
2925 goto error;
2926 }
2927
2928 if (session->kernel_session != NULL) {
2929 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
2930
2931 /* Kernel session buffer type is always GLOBAL */
2932 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
2933
2934 index++;
2935 }
2936
2937 if (session->ust_session != NULL) {
2938 (*domains)[index].type = LTTNG_DOMAIN_UST;
2939 (*domains)[index].buf_type = session->ust_session->buffer_type;
2940 index++;
2941
2942 rcu_read_lock();
2943 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
2944 agt, node.node) {
2945 if (agt->being_used) {
2946 (*domains)[index].type = agt->domain;
2947 (*domains)[index].buf_type = session->ust_session->buffer_type;
2948 index++;
2949 }
2950 }
2951 rcu_read_unlock();
2952 }
2953 end:
2954 return nb_dom;
2955
2956 error:
2957 /* Return negative value to differentiate return code */
2958 return -ret;
2959 }
2960
2961
2962 /*
2963 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2964 */
2965 ssize_t cmd_list_channels(enum lttng_domain_type domain,
2966 struct ltt_session *session, struct lttng_channel **channels)
2967 {
2968 ssize_t nb_chan = 0, payload_size = 0, ret;
2969
2970 switch (domain) {
2971 case LTTNG_DOMAIN_KERNEL:
2972 if (session->kernel_session != NULL) {
2973 nb_chan = session->kernel_session->channel_count;
2974 }
2975 DBG3("Number of kernel channels %zd", nb_chan);
2976 if (nb_chan <= 0) {
2977 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2978 goto end;
2979 }
2980 break;
2981 case LTTNG_DOMAIN_UST:
2982 if (session->ust_session != NULL) {
2983 rcu_read_lock();
2984 nb_chan = lttng_ht_get_count(
2985 session->ust_session->domain_global.channels);
2986 rcu_read_unlock();
2987 }
2988 DBG3("Number of UST global channels %zd", nb_chan);
2989 if (nb_chan < 0) {
2990 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
2991 goto end;
2992 }
2993 break;
2994 default:
2995 ret = -LTTNG_ERR_UND;
2996 goto end;
2997 }
2998
2999 if (nb_chan > 0) {
3000 const size_t channel_size = sizeof(struct lttng_channel) +
3001 sizeof(struct lttcomm_channel_extended);
3002 struct lttcomm_channel_extended *channel_exts;
3003
3004 payload_size = nb_chan * channel_size;
3005 *channels = zmalloc(payload_size);
3006 if (*channels == NULL) {
3007 ret = -LTTNG_ERR_FATAL;
3008 goto end;
3009 }
3010
3011 channel_exts = ((void *) *channels) +
3012 (nb_chan * sizeof(struct lttng_channel));
3013 list_lttng_channels(domain, session, *channels, channel_exts);
3014 } else {
3015 *channels = NULL;
3016 }
3017
3018 ret = payload_size;
3019 end:
3020 return ret;
3021 }
3022
3023 /*
3024 * Command LTTNG_LIST_EVENTS processed by the client thread.
3025 */
3026 ssize_t cmd_list_events(enum lttng_domain_type domain,
3027 struct ltt_session *session, char *channel_name,
3028 struct lttng_event **events, size_t *total_size)
3029 {
3030 int ret = 0;
3031 ssize_t nb_event = 0;
3032
3033 switch (domain) {
3034 case LTTNG_DOMAIN_KERNEL:
3035 if (session->kernel_session != NULL) {
3036 nb_event = list_lttng_kernel_events(channel_name,
3037 session->kernel_session, events,
3038 total_size);
3039 }
3040 break;
3041 case LTTNG_DOMAIN_UST:
3042 {
3043 if (session->ust_session != NULL) {
3044 nb_event = list_lttng_ust_global_events(channel_name,
3045 &session->ust_session->domain_global, events,
3046 total_size);
3047 }
3048 break;
3049 }
3050 case LTTNG_DOMAIN_LOG4J:
3051 case LTTNG_DOMAIN_JUL:
3052 case LTTNG_DOMAIN_PYTHON:
3053 if (session->ust_session) {
3054 struct lttng_ht_iter iter;
3055 struct agent *agt;
3056
3057 rcu_read_lock();
3058 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3059 &iter.iter, agt, node.node) {
3060 if (agt->domain == domain) {
3061 nb_event = list_lttng_agent_events(
3062 agt, events,
3063 total_size);
3064 break;
3065 }
3066 }
3067 rcu_read_unlock();
3068 }
3069 break;
3070 default:
3071 ret = LTTNG_ERR_UND;
3072 goto error;
3073 }
3074
3075 return nb_event;
3076
3077 error:
3078 /* Return negative value to differentiate return code */
3079 return -ret;
3080 }
3081
3082 /*
3083 * Using the session list, filled a lttng_session array to send back to the
3084 * client for session listing.
3085 *
3086 * The session list lock MUST be acquired before calling this function. Use
3087 * session_lock_list() and session_unlock_list().
3088 */
3089 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
3090 gid_t gid)
3091 {
3092 int ret;
3093 unsigned int i = 0;
3094 struct ltt_session *session;
3095 struct ltt_session_list *list = session_get_list();
3096
3097 DBG("Getting all available session for UID %d GID %d",
3098 uid, gid);
3099 /*
3100 * Iterate over session list and append data after the control struct in
3101 * the buffer.
3102 */
3103 cds_list_for_each_entry(session, &list->head, list) {
3104 /*
3105 * Only list the sessions the user can control.
3106 */
3107 if (!session_access_ok(session, uid, gid)) {
3108 continue;
3109 }
3110
3111 struct ltt_kernel_session *ksess = session->kernel_session;
3112 struct ltt_ust_session *usess = session->ust_session;
3113
3114 if (session->consumer->type == CONSUMER_DST_NET ||
3115 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3116 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3117 ret = build_network_session_path(sessions[i].path,
3118 sizeof(sessions[i].path), session);
3119 } else {
3120 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3121 session->consumer->dst.trace_path);
3122 }
3123 if (ret < 0) {
3124 PERROR("snprintf session path");
3125 continue;
3126 }
3127
3128 strncpy(sessions[i].name, session->name, NAME_MAX);
3129 sessions[i].name[NAME_MAX - 1] = '\0';
3130 sessions[i].enabled = session->active;
3131 sessions[i].snapshot_mode = session->snapshot_mode;
3132 sessions[i].live_timer_interval = session->live_timer;
3133 i++;
3134 }
3135 }
3136
3137 /*
3138 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3139 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3140 */
3141 int cmd_data_pending(struct ltt_session *session)
3142 {
3143 int ret;
3144 struct ltt_kernel_session *ksess = session->kernel_session;
3145 struct ltt_ust_session *usess = session->ust_session;
3146
3147 assert(session);
3148
3149 /* Session MUST be stopped to ask for data availability. */
3150 if (session->active) {
3151 ret = LTTNG_ERR_SESSION_STARTED;
3152 goto error;
3153 } else {
3154 /*
3155 * If stopped, just make sure we've started before else the above call
3156 * will always send that there is data pending.
3157 *
3158 * The consumer assumes that when the data pending command is received,
3159 * the trace has been started before or else no output data is written
3160 * by the streams which is a condition for data pending. So, this is
3161 * *VERY* important that we don't ask the consumer before a start
3162 * trace.
3163 */
3164 if (!session->has_been_started) {
3165 ret = 0;
3166 goto error;
3167 }
3168 }
3169
3170 if (ksess && ksess->consumer) {
3171 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3172 if (ret == 1) {
3173 /* Data is still being extracted for the kernel. */
3174 goto error;
3175 }
3176 }
3177
3178 if (usess && usess->consumer) {
3179 ret = consumer_is_data_pending(usess->id, usess->consumer);
3180 if (ret == 1) {
3181 /* Data is still being extracted for the kernel. */
3182 goto error;
3183 }
3184 }
3185
3186 /* Data is ready to be read by a viewer */
3187 ret = 0;
3188
3189 error:
3190 return ret;
3191 }
3192
3193 /*
3194 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3195 *
3196 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3197 */
3198 int cmd_snapshot_add_output(struct ltt_session *session,
3199 struct lttng_snapshot_output *output, uint32_t *id)
3200 {
3201 int ret;
3202 struct snapshot_output *new_output;
3203
3204 assert(session);
3205 assert(output);
3206
3207 DBG("Cmd snapshot add output for session %s", session->name);
3208
3209 /*
3210 * Permission denied to create an output if the session is not
3211 * set in no output mode.
3212 */
3213 if (session->output_traces) {
3214 ret = LTTNG_ERR_EPERM;
3215 goto error;
3216 }
3217
3218 /* Only one output is allowed until we have the "tee" feature. */
3219 if (session->snapshot.nb_output == 1) {
3220 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3221 goto error;
3222 }
3223
3224 new_output = snapshot_output_alloc();
3225 if (!new_output) {
3226 ret = LTTNG_ERR_NOMEM;
3227 goto error;
3228 }
3229
3230 ret = snapshot_output_init(output->max_size, output->name,
3231 output->ctrl_url, output->data_url, session->consumer, new_output,
3232 &session->snapshot);
3233 if (ret < 0) {
3234 if (ret == -ENOMEM) {
3235 ret = LTTNG_ERR_NOMEM;
3236 } else {
3237 ret = LTTNG_ERR_INVALID;
3238 }
3239 goto free_error;
3240 }
3241
3242 rcu_read_lock();
3243 snapshot_add_output(&session->snapshot, new_output);
3244 if (id) {
3245 *id = new_output->id;
3246 }
3247 rcu_read_unlock();
3248
3249 return LTTNG_OK;
3250
3251 free_error:
3252 snapshot_output_destroy(new_output);
3253 error:
3254 return ret;
3255 }
3256
3257 /*
3258 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3259 *
3260 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3261 */
3262 int cmd_snapshot_del_output(struct ltt_session *session,
3263 struct lttng_snapshot_output *output)
3264 {
3265 int ret;
3266 struct snapshot_output *sout = NULL;
3267
3268 assert(session);
3269 assert(output);
3270
3271 rcu_read_lock();
3272
3273 /*
3274 * Permission denied to create an output if the session is not
3275 * set in no output mode.
3276 */
3277 if (session->output_traces) {
3278 ret = LTTNG_ERR_EPERM;
3279 goto error;
3280 }
3281
3282 if (output->id) {
3283 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3284 session->name);
3285 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3286 } else if (*output->name != '\0') {
3287 DBG("Cmd snapshot del output name %s for session %s", output->name,
3288 session->name);
3289 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3290 }
3291 if (!sout) {
3292 ret = LTTNG_ERR_INVALID;
3293 goto error;
3294 }
3295
3296 snapshot_delete_output(&session->snapshot, sout);
3297 snapshot_output_destroy(sout);
3298 ret = LTTNG_OK;
3299
3300 error:
3301 rcu_read_unlock();
3302 return ret;
3303 }
3304
3305 /*
3306 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3307 *
3308 * If no output is available, outputs is untouched and 0 is returned.
3309 *
3310 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3311 */
3312 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3313 struct lttng_snapshot_output **outputs)
3314 {
3315 int ret, idx = 0;
3316 struct lttng_snapshot_output *list = NULL;
3317 struct lttng_ht_iter iter;
3318 struct snapshot_output *output;
3319
3320 assert(session);
3321 assert(outputs);
3322
3323 DBG("Cmd snapshot list outputs for session %s", session->name);
3324
3325 /*
3326 * Permission denied to create an output if the session is not
3327 * set in no output mode.
3328 */
3329 if (session->output_traces) {
3330 ret = -LTTNG_ERR_EPERM;
3331 goto error;
3332 }
3333
3334 if (session->snapshot.nb_output == 0) {
3335 ret = 0;
3336 goto error;
3337 }
3338
3339 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3340 if (!list) {
3341 ret = -LTTNG_ERR_NOMEM;
3342 goto error;
3343 }
3344
3345 /* Copy list from session to the new list object. */
3346 rcu_read_lock();
3347 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3348 output, node.node) {
3349 assert(output->consumer);
3350 list[idx].id = output->id;
3351 list[idx].max_size = output->max_size;
3352 strncpy(list[idx].name, output->name, sizeof(list[idx].name));
3353 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3354 strncpy(list[idx].ctrl_url, output->consumer->dst.trace_path,
3355 sizeof(list[idx].ctrl_url));
3356 } else {
3357 /* Control URI. */
3358 ret = uri_to_str_url(&output->consumer->dst.net.control,
3359 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3360 if (ret < 0) {
3361 ret = -LTTNG_ERR_NOMEM;
3362 goto error;
3363 }
3364
3365 /* Data URI. */
3366 ret = uri_to_str_url(&output->consumer->dst.net.data,
3367 list[idx].data_url, sizeof(list[idx].data_url));
3368 if (ret < 0) {
3369 ret = -LTTNG_ERR_NOMEM;
3370 goto error;
3371 }
3372 }
3373 idx++;
3374 }
3375
3376 *outputs = list;
3377 list = NULL;
3378 ret = session->snapshot.nb_output;
3379 error:
3380 free(list);
3381 rcu_read_unlock();
3382 return ret;
3383 }
3384
3385 /*
3386 * Check if we can regenerate the metadata for this session.
3387 * Only kernel, UST per-uid and non-live sessions are supported.
3388 *
3389 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3390 */
3391 static
3392 int check_metadata_regenerate_support(struct ltt_session *session)
3393 {
3394 int ret;
3395
3396 assert(session);
3397
3398 if (session->live_timer != 0) {
3399 ret = LTTNG_ERR_LIVE_SESSION;
3400 goto end;
3401 }
3402 if (!session->active) {
3403 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3404 goto end;
3405 }
3406 if (session->ust_session) {
3407 switch (session->ust_session->buffer_type) {
3408 case LTTNG_BUFFER_PER_UID:
3409 break;
3410 case LTTNG_BUFFER_PER_PID:
3411 ret = LTTNG_ERR_PER_PID_SESSION;
3412 goto end;
3413 default:
3414 assert(0);
3415 ret = LTTNG_ERR_UNK;
3416 goto end;
3417 }
3418 }
3419 if (session->consumer->type == CONSUMER_DST_NET &&
3420 session->consumer->relay_minor_version < 8) {
3421 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
3422 goto end;
3423 }
3424 ret = 0;
3425
3426 end:
3427 return ret;
3428 }
3429
3430 static
3431 int ust_metadata_regenerate(struct ltt_ust_session *usess)
3432 {
3433 int ret = 0;
3434 struct buffer_reg_uid *uid_reg = NULL;
3435 struct buffer_reg_session *session_reg = NULL;
3436
3437 rcu_read_lock();
3438 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
3439 struct ust_registry_session *registry;
3440 struct ust_registry_channel *chan;
3441 struct lttng_ht_iter iter_chan;
3442
3443 session_reg = uid_reg->registry;
3444 registry = session_reg->reg.ust;
3445
3446 pthread_mutex_lock(&registry->lock);
3447 registry->metadata_len_sent = 0;
3448 memset(registry->metadata, 0, registry->metadata_alloc_len);
3449 registry->metadata_len = 0;
3450 registry->metadata_version++;
3451 ret = ust_metadata_session_statedump(registry, NULL,
3452 registry->major, registry->minor);
3453 if (ret) {
3454 pthread_mutex_unlock(&registry->lock);
3455 ERR("Failed to generate session metadata (err = %d)",
3456 ret);
3457 goto end;
3458 }
3459 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
3460 chan, node.node) {
3461 struct ust_registry_event *event;
3462 struct lttng_ht_iter iter_event;
3463
3464 ret = ust_metadata_channel_statedump(registry, chan);
3465 if (ret) {
3466 pthread_mutex_unlock(&registry->lock);
3467 ERR("Failed to generate channel metadata "
3468 "(err = %d)", ret);
3469 goto end;
3470 }
3471 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
3472 event, node.node) {
3473 ret = ust_metadata_event_statedump(registry,
3474 chan, event);
3475 if (ret) {
3476 pthread_mutex_unlock(&registry->lock);
3477 ERR("Failed to generate event metadata "
3478 "(err = %d)", ret);
3479 goto end;
3480 }
3481 }
3482 }
3483 pthread_mutex_unlock(&registry->lock);
3484 }
3485
3486 end:
3487 rcu_read_unlock();
3488 return ret;
3489 }
3490
3491 /*
3492 * Command LTTNG_METADATA_REGENERATE from the lttng-ctl library.
3493 *
3494 * Ask the consumer to truncate the existing metadata file(s) and
3495 * then regenerate the metadata. Live and per-pid sessions are not
3496 * supported and return an error.
3497 *
3498 * Return 0 on success or else a LTTNG_ERR code.
3499 */
3500 int cmd_metadata_regenerate(struct ltt_session *session)
3501 {
3502 int ret;
3503
3504 assert(session);
3505
3506 ret = check_metadata_regenerate_support(session);
3507 if (ret) {
3508 goto end;
3509 }
3510
3511 if (session->kernel_session) {
3512 ret = kernctl_session_metadata_regenerate(
3513 session->kernel_session->fd);
3514 if (ret < 0) {
3515 ERR("Failed to regenerate the kernel metadata");
3516 goto end;
3517 }
3518 }
3519
3520 if (session->ust_session) {
3521 ret = ust_metadata_regenerate(session->ust_session);
3522 if (ret < 0) {
3523 ERR("Failed to regenerate the UST metadata");
3524 goto end;
3525 }
3526 }
3527 DBG("Cmd metadata regenerate for session %s", session->name);
3528 ret = LTTNG_OK;
3529
3530 end:
3531 return ret;
3532 }
3533
3534
3535 /*
3536 * Send relayd sockets from snapshot output to consumer. Ignore request if the
3537 * snapshot output is *not* set with a remote destination.
3538 *
3539 * Return 0 on success or a LTTNG_ERR code.
3540 */
3541 static int set_relayd_for_snapshot(struct consumer_output *consumer,
3542 struct snapshot_output *snap_output, struct ltt_session *session)
3543 {
3544 int ret = LTTNG_OK;
3545 struct lttng_ht_iter iter;
3546 struct consumer_socket *socket;
3547
3548 assert(consumer);
3549 assert(snap_output);
3550 assert(session);
3551
3552 DBG2("Set relayd object from snapshot output");
3553
3554 /* Ignore if snapshot consumer output is not network. */
3555 if (snap_output->consumer->type != CONSUMER_DST_NET) {
3556 goto error;
3557 }
3558
3559 /*
3560 * For each consumer socket, create and send the relayd object of the
3561 * snapshot output.
3562 */
3563 rcu_read_lock();
3564 cds_lfht_for_each_entry(snap_output->consumer->socks->ht, &iter.iter,
3565 socket, node.node) {
3566 ret = send_consumer_relayd_sockets(0, session->id,
3567 snap_output->consumer, socket,
3568 session->name, session->hostname,
3569 session->live_timer);
3570 if (ret != LTTNG_OK) {
3571 rcu_read_unlock();
3572 goto error;
3573 }
3574 }
3575 rcu_read_unlock();
3576
3577 error:
3578 return ret;
3579 }
3580
3581 /*
3582 * Record a kernel snapshot.
3583 *
3584 * Return LTTNG_OK on success or a LTTNG_ERR code.
3585 */
3586 static int record_kernel_snapshot(struct ltt_kernel_session *ksess,
3587 struct snapshot_output *output, struct ltt_session *session,
3588 int wait, uint64_t nb_packets_per_stream)
3589 {
3590 int ret;
3591
3592 assert(ksess);
3593 assert(output);
3594 assert(session);
3595
3596 /* Get the datetime for the snapshot output directory. */
3597 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime,
3598 sizeof(output->datetime));
3599 if (!ret) {
3600 ret = LTTNG_ERR_INVALID;
3601 goto error;
3602 }
3603
3604 /*
3605 * Copy kernel session sockets so we can communicate with the right
3606 * consumer for the snapshot record command.
3607 */
3608 ret = consumer_copy_sockets(output->consumer, ksess->consumer);
3609 if (ret < 0) {
3610 ret = LTTNG_ERR_NOMEM;
3611 goto error;
3612 }
3613
3614 ret = set_relayd_for_snapshot(ksess->consumer, output, session);
3615 if (ret != LTTNG_OK) {
3616 goto error_snapshot;
3617 }
3618
3619 ret = kernel_snapshot_record(ksess, output, wait, nb_packets_per_stream);
3620 if (ret != LTTNG_OK) {
3621 goto error_snapshot;
3622 }
3623
3624 ret = LTTNG_OK;
3625 goto end;
3626
3627 error_snapshot:
3628 /* Clean up copied sockets so this output can use some other later on. */
3629 consumer_destroy_output_sockets(output->consumer);
3630 error:
3631 end:
3632 return ret;
3633 }
3634
3635 /*
3636 * Record a UST snapshot.
3637 *
3638 * Return 0 on success or a LTTNG_ERR error code.
3639 */
3640 static int record_ust_snapshot(struct ltt_ust_session *usess,
3641 struct snapshot_output *output, struct ltt_session *session,
3642 int wait, uint64_t nb_packets_per_stream)
3643 {
3644 int ret;
3645
3646 assert(usess);
3647 assert(output);
3648 assert(session);
3649
3650 /* Get the datetime for the snapshot output directory. */
3651 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime,
3652 sizeof(output->datetime));
3653 if (!ret) {
3654 ret = LTTNG_ERR_INVALID;
3655 goto error;
3656 }
3657
3658 /*
3659 * Copy UST session sockets so we can communicate with the right
3660 * consumer for the snapshot record command.
3661 */
3662 ret = consumer_copy_sockets(output->consumer, usess->consumer);
3663 if (ret < 0) {
3664 ret = LTTNG_ERR_NOMEM;
3665 goto error;
3666 }
3667
3668 ret = set_relayd_for_snapshot(usess->consumer, output, session);
3669 if (ret != LTTNG_OK) {
3670 goto error_snapshot;
3671 }
3672
3673 ret = ust_app_snapshot_record(usess, output, wait, nb_packets_per_stream);
3674 if (ret < 0) {
3675 switch (-ret) {
3676 case EINVAL:
3677 ret = LTTNG_ERR_INVALID;
3678 break;
3679 case ENODATA:
3680 ret = LTTNG_ERR_SNAPSHOT_NODATA;
3681 break;
3682 default:
3683 ret = LTTNG_ERR_SNAPSHOT_FAIL;
3684 break;
3685 }
3686 goto error_snapshot;
3687 }
3688
3689 ret = LTTNG_OK;
3690
3691 error_snapshot:
3692 /* Clean up copied sockets so this output can use some other later on. */
3693 consumer_destroy_output_sockets(output->consumer);
3694 error:
3695 return ret;
3696 }
3697
3698 static
3699 uint64_t get_session_size_one_more_packet_per_stream(struct ltt_session *session,
3700 uint64_t cur_nr_packets)
3701 {
3702 uint64_t tot_size = 0;
3703
3704 if (session->kernel_session) {
3705 struct ltt_kernel_channel *chan;
3706 struct ltt_kernel_session *ksess = session->kernel_session;
3707
3708 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
3709 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
3710 /*
3711 * Don't take channel into account if we
3712 * already grab all its packets.
3713 */
3714 continue;
3715 }
3716 tot_size += chan->channel->attr.subbuf_size
3717 * chan->stream_count;
3718 }
3719 }
3720
3721 if (session->ust_session) {
3722 struct ltt_ust_session *usess = session->ust_session;
3723
3724 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
3725 cur_nr_packets);
3726 }
3727
3728 return tot_size;
3729 }
3730
3731 /*
3732 * Calculate the number of packets we can grab from each stream that
3733 * fits within the overall snapshot max size.
3734 *
3735 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
3736 * the number of packets per stream.
3737 *
3738 * TODO: this approach is not perfect: we consider the worse case
3739 * (packet filling the sub-buffers) as an upper bound, but we could do
3740 * better if we do this calculation while we actually grab the packet
3741 * content: we would know how much padding we don't actually store into
3742 * the file.
3743 *
3744 * This algorithm is currently bounded by the number of packets per
3745 * stream.
3746 *
3747 * Since we call this algorithm before actually grabbing the data, it's
3748 * an approximation: for instance, applications could appear/disappear
3749 * in between this call and actually grabbing data.
3750 */
3751 static
3752 int64_t get_session_nb_packets_per_stream(struct ltt_session *session, uint64_t max_size)
3753 {
3754 int64_t size_left;
3755 uint64_t cur_nb_packets = 0;
3756
3757 if (!max_size) {
3758 return 0; /* Infinite */
3759 }
3760
3761 size_left = max_size;
3762 for (;;) {
3763 uint64_t one_more_packet_tot_size;
3764
3765 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(session,
3766 cur_nb_packets);
3767 if (!one_more_packet_tot_size) {
3768 /* We are already grabbing all packets. */
3769 break;
3770 }
3771 size_left -= one_more_packet_tot_size;
3772 if (size_left < 0) {
3773 break;
3774 }
3775 cur_nb_packets++;
3776 }
3777 if (!cur_nb_packets) {
3778 /* Not enough room to grab one packet of each stream, error. */
3779 return -1;
3780 }
3781 return cur_nb_packets;
3782 }
3783
3784 /*
3785 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
3786 *
3787 * The wait parameter is ignored so this call always wait for the snapshot to
3788 * complete before returning.
3789 *
3790 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3791 */
3792 int cmd_snapshot_record(struct ltt_session *session,
3793 struct lttng_snapshot_output *output, int wait)
3794 {
3795 int ret = LTTNG_OK;
3796 unsigned int use_tmp_output = 0;
3797 struct snapshot_output tmp_output;
3798 unsigned int snapshot_success = 0;
3799
3800 assert(session);
3801 assert(output);
3802
3803 DBG("Cmd snapshot record for session %s", session->name);
3804
3805 /*
3806 * Permission denied to create an output if the session is not
3807 * set in no output mode.
3808 */
3809 if (session->output_traces) {
3810 ret = LTTNG_ERR_EPERM;
3811 goto error;
3812 }
3813
3814 /* The session needs to be started at least once. */