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Cleanup: sessiond: fix comments to match with behavior
[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 * SPDX-License-Identifier: GPL-2.0-only
6 *
7 */
8
9 #define _LGPL_SOURCE
10 #include <assert.h>
11 #include <inttypes.h>
12 #include <urcu/list.h>
13 #include <urcu/uatomic.h>
14 #include <sys/stat.h>
15 #include <stdio.h>
16
17 #include <common/defaults.h>
18 #include <common/common.h>
19 #include <common/sessiond-comm/sessiond-comm.h>
20 #include <common/relayd/relayd.h>
21 #include <common/utils.h>
22 #include <common/compat/string.h>
23 #include <common/kernel-ctl/kernel-ctl.h>
24 #include <common/dynamic-buffer.h>
25 #include <common/buffer-view.h>
26 #include <common/payload.h>
27 #include <common/payload-view.h>
28 #include <common/trace-chunk.h>
29 #include <lttng/location-internal.h>
30 #include <lttng/trigger/trigger-internal.h>
31 #include <lttng/condition/condition.h>
32 #include <lttng/condition/condition-internal.h>
33 #include <lttng/condition/event-rule.h>
34 #include <lttng/condition/event-rule-internal.h>
35 #include <lttng/event-rule/event-rule.h>
36 #include <lttng/event-rule/event-rule-internal.h>
37 #include <lttng/action/action.h>
38 #include <lttng/channel.h>
39 #include <lttng/channel-internal.h>
40 #include <lttng/rotate-internal.h>
41 #include <lttng/location-internal.h>
42 #include <lttng/session-internal.h>
43 #include <lttng/userspace-probe-internal.h>
44 #include <lttng/session-descriptor-internal.h>
45 #include <lttng/lttng-error.h>
46 #include <lttng/tracker.h>
47 #include <common/string-utils/string-utils.h>
48
49 #include "channel.h"
50 #include "consumer.h"
51 #include "event.h"
52 #include "health-sessiond.h"
53 #include "kernel.h"
54 #include "kernel-consumer.h"
55 #include "lttng-sessiond.h"
56 #include "utils.h"
57 #include "lttng-syscall.h"
58 #include "agent.h"
59 #include "buffer-registry.h"
60 #include "notification-thread.h"
61 #include "notification-thread-commands.h"
62 #include "rotate.h"
63 #include "rotation-thread.h"
64 #include "timer.h"
65 #include "agent-thread.h"
66 #include "tracker.h"
67
68 #include "cmd.h"
69
70 /* Sleep for 100ms between each check for the shm path's deletion. */
71 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
72
73 struct cmd_destroy_session_reply_context {
74 int reply_sock_fd;
75 bool implicit_rotation_on_destroy;
76 /*
77 * Indicates whether or not an error occurred while launching the
78 * destruction of a session.
79 */
80 enum lttng_error_code destruction_status;
81 };
82
83 static enum lttng_error_code wait_on_path(void *path);
84
85 /*
86 * Command completion handler that is used by the destroy command
87 * when a session that has a non-default shm_path is being destroyed.
88 *
89 * See comment in cmd_destroy_session() for the rationale.
90 */
91 static struct destroy_completion_handler {
92 struct cmd_completion_handler handler;
93 char shm_path[member_sizeof(struct ltt_session, shm_path)];
94 } destroy_completion_handler = {
95 .handler = {
96 .run = wait_on_path,
97 .data = destroy_completion_handler.shm_path
98 },
99 .shm_path = { 0 },
100 };
101
102 static struct cmd_completion_handler *current_completion_handler;
103
104 /*
105 * Used to keep a unique index for each relayd socket created where this value
106 * is associated with streams on the consumer so it can match the right relayd
107 * to send to. It must be accessed with the relayd_net_seq_idx_lock
108 * held.
109 */
110 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
111 static uint64_t relayd_net_seq_idx;
112
113 static int validate_ust_event_name(const char *);
114 static int cmd_enable_event_internal(struct ltt_session *session,
115 const struct lttng_domain *domain,
116 char *channel_name, struct lttng_event *event,
117 char *filter_expression,
118 struct lttng_bytecode *filter,
119 struct lttng_event_exclusion *exclusion,
120 int wpipe);
121
122 /*
123 * Create a session path used by list_lttng_sessions for the case that the
124 * session consumer is on the network.
125 */
126 static int build_network_session_path(char *dst, size_t size,
127 struct ltt_session *session)
128 {
129 int ret, kdata_port, udata_port;
130 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
131 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
132
133 assert(session);
134 assert(dst);
135
136 memset(tmp_urls, 0, sizeof(tmp_urls));
137 memset(tmp_uurl, 0, sizeof(tmp_uurl));
138
139 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
140
141 if (session->kernel_session && session->kernel_session->consumer) {
142 kuri = &session->kernel_session->consumer->dst.net.control;
143 kdata_port = session->kernel_session->consumer->dst.net.data.port;
144 }
145
146 if (session->ust_session && session->ust_session->consumer) {
147 uuri = &session->ust_session->consumer->dst.net.control;
148 udata_port = session->ust_session->consumer->dst.net.data.port;
149 }
150
151 if (uuri == NULL && kuri == NULL) {
152 uri = &session->consumer->dst.net.control;
153 kdata_port = session->consumer->dst.net.data.port;
154 } else if (kuri && uuri) {
155 ret = uri_compare(kuri, uuri);
156 if (ret) {
157 /* Not Equal */
158 uri = kuri;
159 /* Build uuri URL string */
160 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
161 if (ret < 0) {
162 goto error;
163 }
164 } else {
165 uri = kuri;
166 }
167 } else if (kuri && uuri == NULL) {
168 uri = kuri;
169 } else if (uuri && kuri == NULL) {
170 uri = uuri;
171 }
172
173 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
174 if (ret < 0) {
175 goto error;
176 }
177
178 /*
179 * Do we have a UST url set. If yes, this means we have both kernel and UST
180 * to print.
181 */
182 if (*tmp_uurl != '\0') {
183 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
184 tmp_urls, kdata_port, tmp_uurl, udata_port);
185 } else {
186 int dport;
187 if (kuri || (!kuri && !uuri)) {
188 dport = kdata_port;
189 } else {
190 /* No kernel URI, use the UST port. */
191 dport = udata_port;
192 }
193 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
194 }
195
196 error:
197 return ret;
198 }
199
200 /*
201 * Get run-time attributes if the session has been started (discarded events,
202 * lost packets).
203 */
204 static int get_kernel_runtime_stats(struct ltt_session *session,
205 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
206 uint64_t *lost_packets)
207 {
208 int ret;
209
210 if (!session->has_been_started) {
211 ret = 0;
212 *discarded_events = 0;
213 *lost_packets = 0;
214 goto end;
215 }
216
217 ret = consumer_get_discarded_events(session->id, kchan->key,
218 session->kernel_session->consumer,
219 discarded_events);
220 if (ret < 0) {
221 goto end;
222 }
223
224 ret = consumer_get_lost_packets(session->id, kchan->key,
225 session->kernel_session->consumer,
226 lost_packets);
227 if (ret < 0) {
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Get run-time attributes if the session has been started (discarded events,
237 * lost packets).
238 */
239 static int get_ust_runtime_stats(struct ltt_session *session,
240 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
241 uint64_t *lost_packets)
242 {
243 int ret;
244 struct ltt_ust_session *usess;
245
246 if (!discarded_events || !lost_packets) {
247 ret = -1;
248 goto end;
249 }
250
251 usess = session->ust_session;
252 assert(discarded_events);
253 assert(lost_packets);
254
255 if (!usess || !session->has_been_started) {
256 *discarded_events = 0;
257 *lost_packets = 0;
258 ret = 0;
259 goto end;
260 }
261
262 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
263 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
264 &usess->buffer_reg_uid_list,
265 usess->consumer, uchan->id,
266 uchan->attr.overwrite,
267 discarded_events,
268 lost_packets);
269 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
270 ret = ust_app_pid_get_channel_runtime_stats(usess,
271 uchan, usess->consumer,
272 uchan->attr.overwrite,
273 discarded_events,
274 lost_packets);
275 if (ret < 0) {
276 goto end;
277 }
278 *discarded_events += uchan->per_pid_closed_app_discarded;
279 *lost_packets += uchan->per_pid_closed_app_lost;
280 } else {
281 ERR("Unsupported buffer type");
282 assert(0);
283 ret = -1;
284 goto end;
285 }
286
287 end:
288 return ret;
289 }
290
291 /*
292 * Fill lttng_channel array of all channels.
293 */
294 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
295 struct ltt_session *session, struct lttng_channel *channels,
296 struct lttng_channel_extended *chan_exts)
297 {
298 int i = 0, ret = 0;
299 struct ltt_kernel_channel *kchan;
300
301 DBG("Listing channels for session %s", session->name);
302
303 switch (domain) {
304 case LTTNG_DOMAIN_KERNEL:
305 /* Kernel channels */
306 if (session->kernel_session != NULL) {
307 cds_list_for_each_entry(kchan,
308 &session->kernel_session->channel_list.head, list) {
309 uint64_t discarded_events, lost_packets;
310 struct lttng_channel_extended *extended;
311
312 extended = (struct lttng_channel_extended *)
313 kchan->channel->attr.extended.ptr;
314
315 ret = get_kernel_runtime_stats(session, kchan,
316 &discarded_events, &lost_packets);
317 if (ret < 0) {
318 goto end;
319 }
320 /* Copy lttng_channel struct to array */
321 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
322 channels[i].enabled = kchan->enabled;
323 chan_exts[i].discarded_events =
324 discarded_events;
325 chan_exts[i].lost_packets = lost_packets;
326 chan_exts[i].monitor_timer_interval =
327 extended->monitor_timer_interval;
328 chan_exts[i].blocking_timeout = 0;
329 i++;
330 }
331 }
332 break;
333 case LTTNG_DOMAIN_UST:
334 {
335 struct lttng_ht_iter iter;
336 struct ltt_ust_channel *uchan;
337
338 rcu_read_lock();
339 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
340 &iter.iter, uchan, node.node) {
341 uint64_t discarded_events = 0, lost_packets = 0;
342
343 if (lttng_strncpy(channels[i].name, uchan->name,
344 LTTNG_SYMBOL_NAME_LEN)) {
345 break;
346 }
347 channels[i].attr.overwrite = uchan->attr.overwrite;
348 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
349 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
350 channels[i].attr.switch_timer_interval =
351 uchan->attr.switch_timer_interval;
352 channels[i].attr.read_timer_interval =
353 uchan->attr.read_timer_interval;
354 channels[i].enabled = uchan->enabled;
355 channels[i].attr.tracefile_size = uchan->tracefile_size;
356 channels[i].attr.tracefile_count = uchan->tracefile_count;
357
358 /*
359 * Map enum lttng_ust_output to enum lttng_event_output.
360 */
361 switch (uchan->attr.output) {
362 case LTTNG_UST_MMAP:
363 channels[i].attr.output = LTTNG_EVENT_MMAP;
364 break;
365 default:
366 /*
367 * LTTNG_UST_MMAP is the only supported UST
368 * output mode.
369 */
370 assert(0);
371 break;
372 }
373
374 chan_exts[i].monitor_timer_interval =
375 uchan->monitor_timer_interval;
376 chan_exts[i].blocking_timeout =
377 uchan->attr.u.s.blocking_timeout;
378
379 ret = get_ust_runtime_stats(session, uchan,
380 &discarded_events, &lost_packets);
381 if (ret < 0) {
382 break;
383 }
384 chan_exts[i].discarded_events = discarded_events;
385 chan_exts[i].lost_packets = lost_packets;
386 i++;
387 }
388 rcu_read_unlock();
389 break;
390 }
391 default:
392 break;
393 }
394
395 end:
396 if (ret < 0) {
397 return -LTTNG_ERR_FATAL;
398 } else {
399 return LTTNG_OK;
400 }
401 }
402
403 static int append_extended_info(const char *filter_expression,
404 struct lttng_event_exclusion *exclusion,
405 struct lttng_userspace_probe_location *probe_location,
406 struct lttng_payload *payload)
407 {
408 int ret = 0;
409 size_t filter_len = 0;
410 size_t nb_exclusions = 0;
411 size_t userspace_probe_location_len = 0;
412 struct lttcomm_event_extended_header extended_header = {};
413 struct lttcomm_event_extended_header *p_extended_header;
414 const size_t original_payload_size = payload->buffer.size;
415
416 ret = lttng_dynamic_buffer_append(&payload->buffer, &extended_header,
417 sizeof(extended_header));
418 if (ret) {
419 goto end;
420 }
421
422 if (filter_expression) {
423 filter_len = strlen(filter_expression) + 1;
424 ret = lttng_dynamic_buffer_append(&payload->buffer,
425 filter_expression, filter_len);
426 if (ret) {
427 goto end;
428 }
429 }
430
431 if (exclusion) {
432 const size_t len = exclusion->count * LTTNG_SYMBOL_NAME_LEN;
433
434 nb_exclusions = exclusion->count;
435
436 ret = lttng_dynamic_buffer_append(
437 &payload->buffer, &exclusion->names, len);
438 if (ret) {
439 goto end;
440 }
441 }
442
443 if (probe_location) {
444 const size_t size_before_probe = payload->buffer.size;
445
446 ret = lttng_userspace_probe_location_serialize(probe_location,
447 payload);
448 if (ret < 0) {
449 ret = -1;
450 goto end;
451 }
452
453 userspace_probe_location_len =
454 payload->buffer.size - size_before_probe;
455 }
456
457 /* Set header fields */
458 p_extended_header = (struct lttcomm_event_extended_header *)
459 (payload->buffer.data + original_payload_size);
460
461 p_extended_header->filter_len = filter_len;
462 p_extended_header->nb_exclusions = nb_exclusions;
463 p_extended_header->userspace_probe_location_len =
464 userspace_probe_location_len;
465
466 ret = 0;
467 end:
468 return ret;
469 }
470
471 /*
472 * Create a list of agent domain events.
473 *
474 * Return number of events in list on success or else a negative value.
475 */
476 static int list_lttng_agent_events(struct agent *agt,
477 struct lttng_payload *payload)
478 {
479 int nb_events = 0, ret = 0;
480 const struct agent_event *agent_event;
481 struct lttng_ht_iter iter;
482
483 assert(agt);
484
485 DBG3("Listing agent events");
486
487 rcu_read_lock();
488 cds_lfht_for_each_entry (
489 agt->events->ht, &iter.iter, agent_event, node.node) {
490 struct lttng_event event = {
491 .enabled = AGENT_EVENT_IS_ENABLED(agent_event),
492 .loglevel = agent_event->loglevel_value,
493 .loglevel_type = agent_event->loglevel_type,
494 };
495
496 ret = lttng_strncpy(event.name, agent_event->name, sizeof(event.name));
497 if (ret) {
498 /* Internal error, invalid name. */
499 ERR("Invalid event name while listing agent events: '%s' exceeds the maximal allowed length of %zu bytes",
500 agent_event->name, sizeof(event.name));
501 ret = -LTTNG_ERR_UNK;
502 goto end;
503 }
504
505 ret = lttng_dynamic_buffer_append(
506 &payload->buffer, &event, sizeof(event));
507 if (ret) {
508 ERR("Failed to append event to payload");
509 ret = -LTTNG_ERR_NOMEM;
510 goto end;
511 }
512
513 nb_events++;
514 }
515
516 cds_lfht_for_each_entry (
517 agt->events->ht, &iter.iter, agent_event, node.node) {
518 /* Append extended info. */
519 ret = append_extended_info(agent_event->filter_expression, NULL,
520 NULL, payload);
521 if (ret) {
522 ERR("Failed to append extended event info to payload");
523 ret = -LTTNG_ERR_NOMEM;
524 goto end;
525 }
526 }
527
528 ret = nb_events;
529 end:
530 rcu_read_unlock();
531 return ret;
532 }
533
534 /*
535 * Create a list of ust global domain events.
536 */
537 static int list_lttng_ust_global_events(char *channel_name,
538 struct ltt_ust_domain_global *ust_global,
539 struct lttng_payload *payload)
540 {
541 int ret = 0;
542 unsigned int nb_events = 0;
543 struct lttng_ht_iter iter;
544 const struct lttng_ht_node_str *node;
545 const struct ltt_ust_channel *uchan;
546 const struct ltt_ust_event *uevent;
547
548 DBG("Listing UST global events for channel %s", channel_name);
549
550 rcu_read_lock();
551
552 lttng_ht_lookup(ust_global->channels, (void *) channel_name, &iter);
553 node = lttng_ht_iter_get_node_str(&iter);
554 if (node == NULL) {
555 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
556 goto end;
557 }
558
559 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
560
561 DBG3("Listing UST global events");
562
563 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
564 struct lttng_event event = {};
565
566 if (uevent->internal) {
567 continue;
568 }
569
570 ret = lttng_strncpy(event.name, uevent->attr.name, sizeof(event.name));
571 if (ret) {
572 /* Internal error, invalid name. */
573 ERR("Invalid event name while listing user space tracer events: '%s' exceeds the maximal allowed length of %zu bytes",
574 uevent->attr.name, sizeof(event.name));
575 ret = -LTTNG_ERR_UNK;
576 goto end;
577 }
578
579 event.enabled = uevent->enabled;
580
581 switch (uevent->attr.instrumentation) {
582 case LTTNG_UST_TRACEPOINT:
583 event.type = LTTNG_EVENT_TRACEPOINT;
584 break;
585 case LTTNG_UST_PROBE:
586 event.type = LTTNG_EVENT_PROBE;
587 break;
588 case LTTNG_UST_FUNCTION:
589 event.type = LTTNG_EVENT_FUNCTION;
590 break;
591 }
592
593 event.loglevel = uevent->attr.loglevel;
594 switch (uevent->attr.loglevel_type) {
595 case LTTNG_UST_LOGLEVEL_ALL:
596 event.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
597 break;
598 case LTTNG_UST_LOGLEVEL_RANGE:
599 event.loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
600 break;
601 case LTTNG_UST_LOGLEVEL_SINGLE:
602 event.loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
603 break;
604 }
605
606 if (uevent->filter) {
607 event.filter = 1;
608 }
609
610 if (uevent->exclusion) {
611 event.exclusion = 1;
612 }
613
614 ret = lttng_dynamic_buffer_append(&payload->buffer, &event, sizeof(event));
615 if (ret) {
616 ERR("Failed to append event to payload");
617 ret = -LTTNG_ERR_NOMEM;
618 goto end;
619 }
620
621 nb_events++;
622 }
623
624 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
625 /* Append extended info. */
626 ret = append_extended_info(uevent->filter_expression,
627 uevent->exclusion, NULL, payload);
628 if (ret) {
629 ERR("Failed to append extended event info to payload");
630 ret = -LTTNG_ERR_FATAL;
631 goto end;
632 }
633 }
634
635 ret = nb_events;
636 end:
637 rcu_read_unlock();
638 return ret;
639 }
640
641 /*
642 * Fill lttng_event array of all kernel events in the channel.
643 */
644 static int list_lttng_kernel_events(char *channel_name,
645 struct ltt_kernel_session *kernel_session,
646 struct lttng_payload *payload)
647 {
648 int ret;
649 unsigned int nb_event;
650 const struct ltt_kernel_event *kevent;
651 const struct ltt_kernel_channel *kchan;
652
653 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
654 if (kchan == NULL) {
655 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
656 goto error;
657 }
658
659 nb_event = kchan->event_count;
660
661 DBG("Listing events for channel %s", kchan->channel->name);
662
663 /* Kernel channels */
664 cds_list_for_each_entry(kevent, &kchan->events_list.head , list) {
665 struct lttng_event event = {};
666
667 ret = lttng_strncpy(event.name, kevent->event->name, sizeof(event.name));
668 if (ret) {
669 /* Internal error, invalid name. */
670 ERR("Invalid event name while listing kernel events: '%s' exceeds the maximal allowed length of %zu bytes",
671 kevent->event->name,
672 sizeof(event.name));
673 ret = -LTTNG_ERR_UNK;
674 goto end;
675 }
676
677 event.enabled = kevent->enabled;
678 event.filter = (unsigned char) !!kevent->filter_expression;
679
680 switch (kevent->event->instrumentation) {
681 case LTTNG_KERNEL_TRACEPOINT:
682 event.type = LTTNG_EVENT_TRACEPOINT;
683 break;
684 case LTTNG_KERNEL_KRETPROBE:
685 event.type = LTTNG_EVENT_FUNCTION;
686 memcpy(&event.attr.probe, &kevent->event->u.kprobe,
687 sizeof(struct lttng_kernel_kprobe));
688 break;
689 case LTTNG_KERNEL_KPROBE:
690 event.type = LTTNG_EVENT_PROBE;
691 memcpy(&event.attr.probe, &kevent->event->u.kprobe,
692 sizeof(struct lttng_kernel_kprobe));
693 break;
694 case LTTNG_KERNEL_UPROBE:
695 event.type = LTTNG_EVENT_USERSPACE_PROBE;
696 break;
697 case LTTNG_KERNEL_FUNCTION:
698 event.type = LTTNG_EVENT_FUNCTION;
699 memcpy(&event.attr.ftrace, &kevent->event->u.ftrace,
700 sizeof(struct lttng_kernel_function));
701 break;
702 case LTTNG_KERNEL_NOOP:
703 event.type = LTTNG_EVENT_NOOP;
704 break;
705 case LTTNG_KERNEL_SYSCALL:
706 event.type = LTTNG_EVENT_SYSCALL;
707 break;
708 case LTTNG_KERNEL_ALL:
709 /* fall-through. */
710 default:
711 assert(0);
712 break;
713 }
714
715 ret = lttng_dynamic_buffer_append(
716 &payload->buffer, &event, sizeof(event));
717 if (ret) {
718 ERR("Failed to append event to payload");
719 ret = -LTTNG_ERR_NOMEM;
720 goto end;
721 }
722 }
723
724 cds_list_for_each_entry(kevent, &kchan->events_list.head , list) {
725 /* Append extended info. */
726 ret = append_extended_info(kevent->filter_expression, NULL,
727 kevent->userspace_probe_location, payload);
728 if (ret) {
729 DBG("Error appending extended info message");
730 ret = -LTTNG_ERR_FATAL;
731 goto error;
732 }
733 }
734
735 end:
736 return nb_event;
737 error:
738 return ret;
739 }
740
741 /*
742 * Add URI so the consumer output object. Set the correct path depending on the
743 * domain adding the default trace directory.
744 */
745 static enum lttng_error_code add_uri_to_consumer(
746 const struct ltt_session *session,
747 struct consumer_output *consumer,
748 struct lttng_uri *uri, enum lttng_domain_type domain)
749 {
750 int ret;
751 enum lttng_error_code ret_code = LTTNG_OK;
752
753 assert(uri);
754
755 if (consumer == NULL) {
756 DBG("No consumer detected. Don't add URI. Stopping.");
757 ret_code = LTTNG_ERR_NO_CONSUMER;
758 goto error;
759 }
760
761 switch (domain) {
762 case LTTNG_DOMAIN_KERNEL:
763 ret = lttng_strncpy(consumer->domain_subdir,
764 DEFAULT_KERNEL_TRACE_DIR,
765 sizeof(consumer->domain_subdir));
766 break;
767 case LTTNG_DOMAIN_UST:
768 ret = lttng_strncpy(consumer->domain_subdir,
769 DEFAULT_UST_TRACE_DIR,
770 sizeof(consumer->domain_subdir));
771 break;
772 default:
773 /*
774 * This case is possible is we try to add the URI to the global
775 * tracing session consumer object which in this case there is
776 * no subdir.
777 */
778 memset(consumer->domain_subdir, 0,
779 sizeof(consumer->domain_subdir));
780 ret = 0;
781 }
782 if (ret) {
783 ERR("Failed to initialize consumer output domain subdirectory");
784 ret_code = LTTNG_ERR_FATAL;
785 goto error;
786 }
787
788 switch (uri->dtype) {
789 case LTTNG_DST_IPV4:
790 case LTTNG_DST_IPV6:
791 DBG2("Setting network URI to consumer");
792
793 if (consumer->type == CONSUMER_DST_NET) {
794 if ((uri->stype == LTTNG_STREAM_CONTROL &&
795 consumer->dst.net.control_isset) ||
796 (uri->stype == LTTNG_STREAM_DATA &&
797 consumer->dst.net.data_isset)) {
798 ret_code = LTTNG_ERR_URL_EXIST;
799 goto error;
800 }
801 } else {
802 memset(&consumer->dst, 0, sizeof(consumer->dst));
803 }
804
805 /* Set URI into consumer output object */
806 ret = consumer_set_network_uri(session, consumer, uri);
807 if (ret < 0) {
808 ret_code = -ret;
809 goto error;
810 } else if (ret == 1) {
811 /*
812 * URI was the same in the consumer so we do not append the subdir
813 * again so to not duplicate output dir.
814 */
815 ret_code = LTTNG_OK;
816 goto error;
817 }
818 break;
819 case LTTNG_DST_PATH:
820 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
821 ret_code = LTTNG_ERR_INVALID;
822 goto error;
823 }
824 DBG2("Setting trace directory path from URI to %s",
825 uri->dst.path);
826 memset(&consumer->dst, 0, sizeof(consumer->dst));
827
828 ret = lttng_strncpy(consumer->dst.session_root_path,
829 uri->dst.path,
830 sizeof(consumer->dst.session_root_path));
831 if (ret) {
832 ret_code = LTTNG_ERR_FATAL;
833 goto error;
834 }
835 consumer->type = CONSUMER_DST_LOCAL;
836 break;
837 }
838
839 ret_code = LTTNG_OK;
840 error:
841 return ret_code;
842 }
843
844 /*
845 * Init tracing by creating trace directory and sending fds kernel consumer.
846 */
847 static int init_kernel_tracing(struct ltt_kernel_session *session)
848 {
849 int ret = 0;
850 struct lttng_ht_iter iter;
851 struct consumer_socket *socket;
852
853 assert(session);
854
855 rcu_read_lock();
856
857 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
858 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
859 socket, node.node) {
860 pthread_mutex_lock(socket->lock);
861 ret = kernel_consumer_send_session(socket, session);
862 pthread_mutex_unlock(socket->lock);
863 if (ret < 0) {
864 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
865 goto error;
866 }
867 }
868 }
869
870 error:
871 rcu_read_unlock();
872 return ret;
873 }
874
875 /*
876 * Create a socket to the relayd using the URI.
877 *
878 * On success, the relayd_sock pointer is set to the created socket.
879 * Else, it remains untouched and an LTTng error code is returned.
880 */
881 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
882 struct lttcomm_relayd_sock **relayd_sock,
883 struct consumer_output *consumer)
884 {
885 int ret;
886 enum lttng_error_code status = LTTNG_OK;
887 struct lttcomm_relayd_sock *rsock;
888
889 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
890 RELAYD_VERSION_COMM_MINOR);
891 if (!rsock) {
892 status = LTTNG_ERR_FATAL;
893 goto error;
894 }
895
896 /*
897 * Connect to relayd so we can proceed with a session creation. This call
898 * can possibly block for an arbitrary amount of time to set the health
899 * state to be in poll execution.
900 */
901 health_poll_entry();
902 ret = relayd_connect(rsock);
903 health_poll_exit();
904 if (ret < 0) {
905 ERR("Unable to reach lttng-relayd");
906 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
907 goto free_sock;
908 }
909
910 /* Create socket for control stream. */
911 if (uri->stype == LTTNG_STREAM_CONTROL) {
912 uint64_t result_flags;
913
914 DBG3("Creating relayd stream socket from URI");
915
916 /* Check relayd version */
917 ret = relayd_version_check(rsock);
918 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
919 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
920 goto close_sock;
921 } else if (ret < 0) {
922 ERR("Unable to reach lttng-relayd");
923 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
924 goto close_sock;
925 }
926 consumer->relay_major_version = rsock->major;
927 consumer->relay_minor_version = rsock->minor;
928 ret = relayd_get_configuration(rsock, 0,
929 &result_flags);
930 if (ret < 0) {
931 ERR("Unable to get relayd configuration");
932 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
933 goto close_sock;
934 }
935 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
936 consumer->relay_allows_clear = true;
937 }
938 } else if (uri->stype == LTTNG_STREAM_DATA) {
939 DBG3("Creating relayd data socket from URI");
940 } else {
941 /* Command is not valid */
942 ERR("Relayd invalid stream type: %d", uri->stype);
943 status = LTTNG_ERR_INVALID;
944 goto close_sock;
945 }
946
947 *relayd_sock = rsock;
948
949 return status;
950
951 close_sock:
952 /* The returned value is not useful since we are on an error path. */
953 (void) relayd_close(rsock);
954 free_sock:
955 free(rsock);
956 error:
957 return status;
958 }
959
960 /*
961 * Connect to the relayd using URI and send the socket to the right consumer.
962 *
963 * The consumer socket lock must be held by the caller.
964 *
965 * Returns LTTNG_OK on success or an LTTng error code on failure.
966 */
967 static enum lttng_error_code send_consumer_relayd_socket(
968 unsigned int session_id,
969 struct lttng_uri *relayd_uri,
970 struct consumer_output *consumer,
971 struct consumer_socket *consumer_sock,
972 const char *session_name, const char *hostname,
973 const char *base_path, int session_live_timer,
974 const uint64_t *current_chunk_id,
975 time_t session_creation_time,
976 bool session_name_contains_creation_time)
977 {
978 int ret;
979 struct lttcomm_relayd_sock *rsock = NULL;
980 enum lttng_error_code status;
981
982 /* Connect to relayd and make version check if uri is the control. */
983 status = create_connect_relayd(relayd_uri, &rsock, consumer);
984 if (status != LTTNG_OK) {
985 goto relayd_comm_error;
986 }
987 assert(rsock);
988
989 /* Set the network sequence index if not set. */
990 if (consumer->net_seq_index == (uint64_t) -1ULL) {
991 pthread_mutex_lock(&relayd_net_seq_idx_lock);
992 /*
993 * Increment net_seq_idx because we are about to transfer the
994 * new relayd socket to the consumer.
995 * Assign unique key so the consumer can match streams.
996 */
997 consumer->net_seq_index = ++relayd_net_seq_idx;
998 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
999 }
1000
1001 /* Send relayd socket to consumer. */
1002 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1003 relayd_uri->stype, session_id,
1004 session_name, hostname, base_path,
1005 session_live_timer, current_chunk_id,
1006 session_creation_time, session_name_contains_creation_time);
1007 if (ret < 0) {
1008 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1009 goto close_sock;
1010 }
1011
1012 /* Flag that the corresponding socket was sent. */
1013 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1014 consumer_sock->control_sock_sent = 1;
1015 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1016 consumer_sock->data_sock_sent = 1;
1017 }
1018
1019 /*
1020 * Close socket which was dup on the consumer side. The session daemon does
1021 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1022 */
1023
1024 close_sock:
1025 if (status != LTTNG_OK) {
1026 /*
1027 * The consumer output for this session should not be used anymore
1028 * since the relayd connection failed thus making any tracing or/and
1029 * streaming not usable.
1030 */
1031 consumer->enabled = 0;
1032 }
1033 (void) relayd_close(rsock);
1034 free(rsock);
1035
1036 relayd_comm_error:
1037 return status;
1038 }
1039
1040 /*
1041 * Send both relayd sockets to a specific consumer and domain. This is a
1042 * helper function to facilitate sending the information to the consumer for a
1043 * session.
1044 *
1045 * The consumer socket lock must be held by the caller.
1046 *
1047 * Returns LTTNG_OK, or an LTTng error code on failure.
1048 */
1049 static enum lttng_error_code send_consumer_relayd_sockets(
1050 enum lttng_domain_type domain,
1051 unsigned int session_id, struct consumer_output *consumer,
1052 struct consumer_socket *sock, const char *session_name,
1053 const char *hostname, const char *base_path, int session_live_timer,
1054 const uint64_t *current_chunk_id, time_t session_creation_time,
1055 bool session_name_contains_creation_time)
1056 {
1057 enum lttng_error_code status = LTTNG_OK;
1058
1059 assert(consumer);
1060 assert(sock);
1061
1062 /* Sending control relayd socket. */
1063 if (!sock->control_sock_sent) {
1064 status = send_consumer_relayd_socket(session_id,
1065 &consumer->dst.net.control, consumer, sock,
1066 session_name, hostname, base_path, session_live_timer,
1067 current_chunk_id, session_creation_time,
1068 session_name_contains_creation_time);
1069 if (status != LTTNG_OK) {
1070 goto error;
1071 }
1072 }
1073
1074 /* Sending data relayd socket. */
1075 if (!sock->data_sock_sent) {
1076 status = send_consumer_relayd_socket(session_id,
1077 &consumer->dst.net.data, consumer, sock,
1078 session_name, hostname, base_path, session_live_timer,
1079 current_chunk_id, session_creation_time,
1080 session_name_contains_creation_time);
1081 if (status != LTTNG_OK) {
1082 goto error;
1083 }
1084 }
1085
1086 error:
1087 return status;
1088 }
1089
1090 /*
1091 * Setup relayd connections for a tracing session. First creates the socket to
1092 * the relayd and send them to the right domain consumer. Consumer type MUST be
1093 * network.
1094 */
1095 int cmd_setup_relayd(struct ltt_session *session)
1096 {
1097 int ret = LTTNG_OK;
1098 struct ltt_ust_session *usess;
1099 struct ltt_kernel_session *ksess;
1100 struct consumer_socket *socket;
1101 struct lttng_ht_iter iter;
1102 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1103
1104 assert(session);
1105
1106 usess = session->ust_session;
1107 ksess = session->kernel_session;
1108
1109 DBG("Setting relayd for session %s", session->name);
1110
1111 rcu_read_lock();
1112 if (session->current_trace_chunk) {
1113 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1114 session->current_trace_chunk, &current_chunk_id.value);
1115
1116 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1117 current_chunk_id.is_set = true;
1118 } else {
1119 ERR("Failed to get current trace chunk id");
1120 ret = LTTNG_ERR_UNK;
1121 goto error;
1122 }
1123 }
1124
1125 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1126 && usess->consumer->enabled) {
1127 /* For each consumer socket, send relayd sockets */
1128 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1129 socket, node.node) {
1130 pthread_mutex_lock(socket->lock);
1131 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1132 usess->consumer, socket,
1133 session->name, session->hostname,
1134 session->base_path,
1135 session->live_timer,
1136 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1137 session->creation_time,
1138 session->name_contains_creation_time);
1139 pthread_mutex_unlock(socket->lock);
1140 if (ret != LTTNG_OK) {
1141 goto error;
1142 }
1143 /* Session is now ready for network streaming. */
1144 session->net_handle = 1;
1145 }
1146 session->consumer->relay_major_version =
1147 usess->consumer->relay_major_version;
1148 session->consumer->relay_minor_version =
1149 usess->consumer->relay_minor_version;
1150 session->consumer->relay_allows_clear =
1151 usess->consumer->relay_allows_clear;
1152 }
1153
1154 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1155 && ksess->consumer->enabled) {
1156 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1157 socket, node.node) {
1158 pthread_mutex_lock(socket->lock);
1159 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1160 ksess->consumer, socket,
1161 session->name, session->hostname,
1162 session->base_path,
1163 session->live_timer,
1164 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1165 session->creation_time,
1166 session->name_contains_creation_time);
1167 pthread_mutex_unlock(socket->lock);
1168 if (ret != LTTNG_OK) {
1169 goto error;
1170 }
1171 /* Session is now ready for network streaming. */
1172 session->net_handle = 1;
1173 }
1174 session->consumer->relay_major_version =
1175 ksess->consumer->relay_major_version;
1176 session->consumer->relay_minor_version =
1177 ksess->consumer->relay_minor_version;
1178 session->consumer->relay_allows_clear =
1179 ksess->consumer->relay_allows_clear;
1180 }
1181
1182 error:
1183 rcu_read_unlock();
1184 return ret;
1185 }
1186
1187 /*
1188 * Start a kernel session by opening all necessary streams.
1189 */
1190 int start_kernel_session(struct ltt_kernel_session *ksess)
1191 {
1192 int ret;
1193 struct ltt_kernel_channel *kchan;
1194
1195 /* Open kernel metadata */
1196 if (ksess->metadata == NULL && ksess->output_traces) {
1197 ret = kernel_open_metadata(ksess);
1198 if (ret < 0) {
1199 ret = LTTNG_ERR_KERN_META_FAIL;
1200 goto error;
1201 }
1202 }
1203
1204 /* Open kernel metadata stream */
1205 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1206 ret = kernel_open_metadata_stream(ksess);
1207 if (ret < 0) {
1208 ERR("Kernel create metadata stream failed");
1209 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1210 goto error;
1211 }
1212 }
1213
1214 /* For each channel */
1215 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1216 if (kchan->stream_count == 0) {
1217 ret = kernel_open_channel_stream(kchan);
1218 if (ret < 0) {
1219 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1220 goto error;
1221 }
1222 /* Update the stream global counter */
1223 ksess->stream_count_global += ret;
1224 }
1225 }
1226
1227 /* Setup kernel consumer socket and send fds to it */
1228 ret = init_kernel_tracing(ksess);
1229 if (ret != 0) {
1230 ret = LTTNG_ERR_KERN_START_FAIL;
1231 goto error;
1232 }
1233
1234 /* This start the kernel tracing */
1235 ret = kernel_start_session(ksess);
1236 if (ret < 0) {
1237 ret = LTTNG_ERR_KERN_START_FAIL;
1238 goto error;
1239 }
1240
1241 /* Quiescent wait after starting trace */
1242 kernel_wait_quiescent();
1243
1244 ksess->active = 1;
1245
1246 ret = LTTNG_OK;
1247
1248 error:
1249 return ret;
1250 }
1251
1252 int stop_kernel_session(struct ltt_kernel_session *ksess)
1253 {
1254 struct ltt_kernel_channel *kchan;
1255 bool error_occurred = false;
1256 int ret;
1257
1258 if (!ksess || !ksess->active) {
1259 return LTTNG_OK;
1260 }
1261 DBG("Stopping kernel tracing");
1262
1263 ret = kernel_stop_session(ksess);
1264 if (ret < 0) {
1265 ret = LTTNG_ERR_KERN_STOP_FAIL;
1266 goto error;
1267 }
1268
1269 kernel_wait_quiescent();
1270
1271 /* Flush metadata after stopping (if exists) */
1272 if (ksess->metadata_stream_fd >= 0) {
1273 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1274 if (ret < 0) {
1275 ERR("Kernel metadata flush failed");
1276 error_occurred = true;
1277 }
1278 }
1279
1280 /* Flush all buffers after stopping */
1281 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1282 ret = kernel_flush_buffer(kchan);
1283 if (ret < 0) {
1284 ERR("Kernel flush buffer error");
1285 error_occurred = true;
1286 }
1287 }
1288
1289 ksess->active = 0;
1290 if (error_occurred) {
1291 ret = LTTNG_ERR_UNK;
1292 } else {
1293 ret = LTTNG_OK;
1294 }
1295 error:
1296 return ret;
1297 }
1298
1299 /*
1300 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1301 */
1302 int cmd_disable_channel(struct ltt_session *session,
1303 enum lttng_domain_type domain, char *channel_name)
1304 {
1305 int ret;
1306 struct ltt_ust_session *usess;
1307
1308 usess = session->ust_session;
1309
1310 rcu_read_lock();
1311
1312 switch (domain) {
1313 case LTTNG_DOMAIN_KERNEL:
1314 {
1315 ret = channel_kernel_disable(session->kernel_session,
1316 channel_name);
1317 if (ret != LTTNG_OK) {
1318 goto error;
1319 }
1320
1321 kernel_wait_quiescent();
1322 break;
1323 }
1324 case LTTNG_DOMAIN_UST:
1325 {
1326 struct ltt_ust_channel *uchan;
1327 struct lttng_ht *chan_ht;
1328
1329 chan_ht = usess->domain_global.channels;
1330
1331 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1332 if (uchan == NULL) {
1333 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1334 goto error;
1335 }
1336
1337 ret = channel_ust_disable(usess, uchan);
1338 if (ret != LTTNG_OK) {
1339 goto error;
1340 }
1341 break;
1342 }
1343 default:
1344 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1345 goto error;
1346 }
1347
1348 ret = LTTNG_OK;
1349
1350 error:
1351 rcu_read_unlock();
1352 return ret;
1353 }
1354
1355 /*
1356 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1357 *
1358 * The wpipe arguments is used as a notifier for the kernel thread.
1359 */
1360 int cmd_enable_channel(struct ltt_session *session,
1361 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1362 {
1363 int ret;
1364 struct ltt_ust_session *usess = session->ust_session;
1365 struct lttng_ht *chan_ht;
1366 size_t len;
1367 struct lttng_channel attr;
1368
1369 assert(session);
1370 assert(_attr);
1371 assert(domain);
1372
1373 attr = *_attr;
1374 len = lttng_strnlen(attr.name, sizeof(attr.name));
1375
1376 /* Validate channel name */
1377 if (attr.name[0] == '.' ||
1378 memchr(attr.name, '/', len) != NULL) {
1379 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1380 goto end;
1381 }
1382
1383 DBG("Enabling channel %s for session %s", attr.name, session->name);
1384
1385 rcu_read_lock();
1386
1387 /*
1388 * Don't try to enable a channel if the session has been started at
1389 * some point in time before. The tracer does not allow it.
1390 */
1391 if (session->has_been_started) {
1392 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1393 goto error;
1394 }
1395
1396 /*
1397 * If the session is a live session, remove the switch timer, the
1398 * live timer does the same thing but sends also synchronisation
1399 * beacons for inactive streams.
1400 */
1401 if (session->live_timer > 0) {
1402 attr.attr.live_timer_interval = session->live_timer;
1403 attr.attr.switch_timer_interval = 0;
1404 }
1405
1406 /* Check for feature support */
1407 switch (domain->type) {
1408 case LTTNG_DOMAIN_KERNEL:
1409 {
1410 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1411 /* Sampling position of buffer is not supported */
1412 WARN("Kernel tracer does not support buffer monitoring. "
1413 "Setting the monitor interval timer to 0 "
1414 "(disabled) for channel '%s' of session '%s'",
1415 attr.name, session->name);
1416 lttng_channel_set_monitor_timer_interval(&attr, 0);
1417 }
1418 break;
1419 }
1420 case LTTNG_DOMAIN_UST:
1421 break;
1422 case LTTNG_DOMAIN_JUL:
1423 case LTTNG_DOMAIN_LOG4J:
1424 case LTTNG_DOMAIN_PYTHON:
1425 if (!agent_tracing_is_enabled()) {
1426 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1427 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1428 goto error;
1429 }
1430 break;
1431 default:
1432 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1433 goto error;
1434 }
1435
1436 switch (domain->type) {
1437 case LTTNG_DOMAIN_KERNEL:
1438 {
1439 struct ltt_kernel_channel *kchan;
1440
1441 kchan = trace_kernel_get_channel_by_name(attr.name,
1442 session->kernel_session);
1443 if (kchan == NULL) {
1444 if (session->snapshot.nb_output > 0 ||
1445 session->snapshot_mode) {
1446 /* Enforce mmap output for snapshot sessions. */
1447 attr.attr.output = LTTNG_EVENT_MMAP;
1448 }
1449 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1450 if (attr.name[0] != '\0') {
1451 session->kernel_session->has_non_default_channel = 1;
1452 }
1453 } else {
1454 ret = channel_kernel_enable(session->kernel_session, kchan);
1455 }
1456
1457 if (ret != LTTNG_OK) {
1458 goto error;
1459 }
1460
1461 kernel_wait_quiescent();
1462 break;
1463 }
1464 case LTTNG_DOMAIN_UST:
1465 case LTTNG_DOMAIN_JUL:
1466 case LTTNG_DOMAIN_LOG4J:
1467 case LTTNG_DOMAIN_PYTHON:
1468 {
1469 struct ltt_ust_channel *uchan;
1470
1471 /*
1472 * FIXME
1473 *
1474 * Current agent implementation limitations force us to allow
1475 * only one channel at once in "agent" subdomains. Each
1476 * subdomain has a default channel name which must be strictly
1477 * adhered to.
1478 */
1479 if (domain->type == LTTNG_DOMAIN_JUL) {
1480 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1481 LTTNG_SYMBOL_NAME_LEN)) {
1482 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1483 goto error;
1484 }
1485 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1486 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1487 LTTNG_SYMBOL_NAME_LEN)) {
1488 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1489 goto error;
1490 }
1491 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1492 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1493 LTTNG_SYMBOL_NAME_LEN)) {
1494 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1495 goto error;
1496 }
1497 }
1498
1499 chan_ht = usess->domain_global.channels;
1500
1501 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1502 if (uchan == NULL) {
1503 ret = channel_ust_create(usess, &attr, domain->buf_type);
1504 if (attr.name[0] != '\0') {
1505 usess->has_non_default_channel = 1;
1506 }
1507 } else {
1508 ret = channel_ust_enable(usess, uchan);
1509 }
1510 break;
1511 }
1512 default:
1513 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1514 goto error;
1515 }
1516
1517 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1518 session->has_non_mmap_channel = true;
1519 }
1520 error:
1521 rcu_read_unlock();
1522 end:
1523 return ret;
1524 }
1525
1526 enum lttng_error_code cmd_process_attr_tracker_get_tracking_policy(
1527 struct ltt_session *session,
1528 enum lttng_domain_type domain,
1529 enum lttng_process_attr process_attr,
1530 enum lttng_tracking_policy *policy)
1531 {
1532 enum lttng_error_code ret_code = LTTNG_OK;
1533 const struct process_attr_tracker *tracker;
1534
1535 switch (domain) {
1536 case LTTNG_DOMAIN_KERNEL:
1537 if (!session->kernel_session) {
1538 ret_code = LTTNG_ERR_INVALID;
1539 goto end;
1540 }
1541 tracker = kernel_get_process_attr_tracker(
1542 session->kernel_session, process_attr);
1543 break;
1544 case LTTNG_DOMAIN_UST:
1545 if (!session->ust_session) {
1546 ret_code = LTTNG_ERR_INVALID;
1547 goto end;
1548 }
1549 tracker = trace_ust_get_process_attr_tracker(
1550 session->ust_session, process_attr);
1551 break;
1552 default:
1553 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1554 goto end;
1555 }
1556 if (tracker) {
1557 *policy = process_attr_tracker_get_tracking_policy(tracker);
1558 } else {
1559 ret_code = LTTNG_ERR_INVALID;
1560 }
1561 end:
1562 return ret_code;
1563 }
1564
1565 enum lttng_error_code cmd_process_attr_tracker_set_tracking_policy(
1566 struct ltt_session *session,
1567 enum lttng_domain_type domain,
1568 enum lttng_process_attr process_attr,
1569 enum lttng_tracking_policy policy)
1570 {
1571 enum lttng_error_code ret_code = LTTNG_OK;
1572
1573 switch (policy) {
1574 case LTTNG_TRACKING_POLICY_INCLUDE_SET:
1575 case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
1576 case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
1577 break;
1578 default:
1579 ret_code = LTTNG_ERR_INVALID;
1580 goto end;
1581 }
1582
1583 switch (domain) {
1584 case LTTNG_DOMAIN_KERNEL:
1585 if (!session->kernel_session) {
1586 ret_code = LTTNG_ERR_INVALID;
1587 goto end;
1588 }
1589 ret_code = kernel_process_attr_tracker_set_tracking_policy(
1590 session->kernel_session, process_attr, policy);
1591 break;
1592 case LTTNG_DOMAIN_UST:
1593 if (!session->ust_session) {
1594 ret_code = LTTNG_ERR_INVALID;
1595 goto end;
1596 }
1597 ret_code = trace_ust_process_attr_tracker_set_tracking_policy(
1598 session->ust_session, process_attr, policy);
1599 break;
1600 default:
1601 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1602 break;
1603 }
1604 end:
1605 return ret_code;
1606 }
1607
1608 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_add_value(
1609 struct ltt_session *session,
1610 enum lttng_domain_type domain,
1611 enum lttng_process_attr process_attr,
1612 const struct process_attr_value *value)
1613 {
1614 enum lttng_error_code ret_code = LTTNG_OK;
1615
1616 switch (domain) {
1617 case LTTNG_DOMAIN_KERNEL:
1618 if (!session->kernel_session) {
1619 ret_code = LTTNG_ERR_INVALID;
1620 goto end;
1621 }
1622 ret_code = kernel_process_attr_tracker_inclusion_set_add_value(
1623 session->kernel_session, process_attr, value);
1624 break;
1625 case LTTNG_DOMAIN_UST:
1626 if (!session->ust_session) {
1627 ret_code = LTTNG_ERR_INVALID;
1628 goto end;
1629 }
1630 ret_code = trace_ust_process_attr_tracker_inclusion_set_add_value(
1631 session->ust_session, process_attr, value);
1632 break;
1633 default:
1634 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1635 break;
1636 }
1637 end:
1638 return ret_code;
1639 }
1640
1641 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_remove_value(
1642 struct ltt_session *session,
1643 enum lttng_domain_type domain,
1644 enum lttng_process_attr process_attr,
1645 const struct process_attr_value *value)
1646 {
1647 enum lttng_error_code ret_code = LTTNG_OK;
1648
1649 switch (domain) {
1650 case LTTNG_DOMAIN_KERNEL:
1651 if (!session->kernel_session) {
1652 ret_code = LTTNG_ERR_INVALID;
1653 goto end;
1654 }
1655 ret_code = kernel_process_attr_tracker_inclusion_set_remove_value(
1656 session->kernel_session, process_attr, value);
1657 break;
1658 case LTTNG_DOMAIN_UST:
1659 if (!session->ust_session) {
1660 ret_code = LTTNG_ERR_INVALID;
1661 goto end;
1662 }
1663 ret_code = trace_ust_process_attr_tracker_inclusion_set_remove_value(
1664 session->ust_session, process_attr, value);
1665 break;
1666 default:
1667 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1668 break;
1669 }
1670 end:
1671 return ret_code;
1672 }
1673
1674 enum lttng_error_code cmd_process_attr_tracker_get_inclusion_set(
1675 struct ltt_session *session,
1676 enum lttng_domain_type domain,
1677 enum lttng_process_attr process_attr,
1678 struct lttng_process_attr_values **values)
1679 {
1680 enum lttng_error_code ret_code = LTTNG_OK;
1681 const struct process_attr_tracker *tracker;
1682 enum process_attr_tracker_status status;
1683
1684 switch (domain) {
1685 case LTTNG_DOMAIN_KERNEL:
1686 if (!session->kernel_session) {
1687 ret_code = LTTNG_ERR_INVALID;
1688 goto end;
1689 }
1690 tracker = kernel_get_process_attr_tracker(
1691 session->kernel_session, process_attr);
1692 break;
1693 case LTTNG_DOMAIN_UST:
1694 if (!session->ust_session) {
1695 ret_code = LTTNG_ERR_INVALID;
1696 goto end;
1697 }
1698 tracker = trace_ust_get_process_attr_tracker(
1699 session->ust_session, process_attr);
1700 break;
1701 default:
1702 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1703 goto end;
1704 }
1705
1706 if (!tracker) {
1707 ret_code = LTTNG_ERR_INVALID;
1708 goto end;
1709 }
1710
1711 status = process_attr_tracker_get_inclusion_set(tracker, values);
1712 switch (status) {
1713 case PROCESS_ATTR_TRACKER_STATUS_OK:
1714 ret_code = LTTNG_OK;
1715 break;
1716 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1717 ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1718 break;
1719 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1720 ret_code = LTTNG_ERR_NOMEM;
1721 break;
1722 default:
1723 ret_code = LTTNG_ERR_UNK;
1724 break;
1725 }
1726
1727 end:
1728 return ret_code;
1729 }
1730
1731 /*
1732 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1733 */
1734 int cmd_disable_event(struct ltt_session *session,
1735 enum lttng_domain_type domain, const char *channel_name,
1736 const struct lttng_event *event)
1737 {
1738 int ret;
1739 const char *event_name;
1740
1741 DBG("Disable event command for event \'%s\'", event->name);
1742
1743 event_name = event->name;
1744
1745 /* Error out on unhandled search criteria */
1746 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1747 || event->pid || event->filter || event->exclusion) {
1748 ret = LTTNG_ERR_UNK;
1749 goto error;
1750 }
1751
1752 rcu_read_lock();
1753
1754 switch (domain) {
1755 case LTTNG_DOMAIN_KERNEL:
1756 {
1757 struct ltt_kernel_channel *kchan;
1758 struct ltt_kernel_session *ksess;
1759
1760 ksess = session->kernel_session;
1761
1762 /*
1763 * If a non-default channel has been created in the
1764 * session, explicitely require that -c chan_name needs
1765 * to be provided.
1766 */
1767 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1768 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1769 goto error_unlock;
1770 }
1771
1772 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1773 if (kchan == NULL) {
1774 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1775 goto error_unlock;
1776 }
1777
1778 switch (event->type) {
1779 case LTTNG_EVENT_ALL:
1780 case LTTNG_EVENT_TRACEPOINT:
1781 case LTTNG_EVENT_SYSCALL:
1782 case LTTNG_EVENT_PROBE:
1783 case LTTNG_EVENT_FUNCTION:
1784 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1785 if (event_name[0] == '\0') {
1786 ret = event_kernel_disable_event(kchan,
1787 NULL, event->type);
1788 } else {
1789 ret = event_kernel_disable_event(kchan,
1790 event_name, event->type);
1791 }
1792 if (ret != LTTNG_OK) {
1793 goto error_unlock;
1794 }
1795 break;
1796 default:
1797 ret = LTTNG_ERR_UNK;
1798 goto error_unlock;
1799 }
1800
1801 kernel_wait_quiescent();
1802 break;
1803 }
1804 case LTTNG_DOMAIN_UST:
1805 {
1806 struct ltt_ust_channel *uchan;
1807 struct ltt_ust_session *usess;
1808
1809 usess = session->ust_session;
1810
1811 if (validate_ust_event_name(event_name)) {
1812 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1813 goto error_unlock;
1814 }
1815
1816 /*
1817 * If a non-default channel has been created in the
1818 * session, explicitly require that -c chan_name needs
1819 * to be provided.
1820 */
1821 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1822 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1823 goto error_unlock;
1824 }
1825
1826 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1827 channel_name);
1828 if (uchan == NULL) {
1829 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1830 goto error_unlock;
1831 }
1832
1833 switch (event->type) {
1834 case LTTNG_EVENT_ALL:
1835 /*
1836 * An empty event name means that everything
1837 * should be disabled.
1838 */
1839 if (event->name[0] == '\0') {
1840 ret = event_ust_disable_all_tracepoints(usess, uchan);
1841 } else {
1842 ret = event_ust_disable_tracepoint(usess, uchan,
1843 event_name);
1844 }
1845 if (ret != LTTNG_OK) {
1846 goto error_unlock;
1847 }
1848 break;
1849 default:
1850 ret = LTTNG_ERR_UNK;
1851 goto error_unlock;
1852 }
1853
1854 DBG3("Disable UST event %s in channel %s completed", event_name,
1855 channel_name);
1856 break;
1857 }
1858 case LTTNG_DOMAIN_LOG4J:
1859 case LTTNG_DOMAIN_JUL:
1860 case LTTNG_DOMAIN_PYTHON:
1861 {
1862 struct agent *agt;
1863 struct ltt_ust_session *usess = session->ust_session;
1864
1865 assert(usess);
1866
1867 switch (event->type) {
1868 case LTTNG_EVENT_ALL:
1869 break;
1870 default:
1871 ret = LTTNG_ERR_UNK;
1872 goto error_unlock;
1873 }
1874
1875 agt = trace_ust_find_agent(usess, domain);
1876 if (!agt) {
1877 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1878 goto error_unlock;
1879 }
1880 /*
1881 * An empty event name means that everything
1882 * should be disabled.
1883 */
1884 if (event->name[0] == '\0') {
1885 ret = event_agent_disable_all(usess, agt);
1886 } else {
1887 ret = event_agent_disable(usess, agt, event_name);
1888 }
1889 if (ret != LTTNG_OK) {
1890 goto error_unlock;
1891 }
1892
1893 break;
1894 }
1895 default:
1896 ret = LTTNG_ERR_UND;
1897 goto error_unlock;
1898 }
1899
1900 ret = LTTNG_OK;
1901
1902 error_unlock:
1903 rcu_read_unlock();
1904 error:
1905 return ret;
1906 }
1907
1908 /*
1909 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1910 */
1911 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1912 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1913 {
1914 int ret, chan_kern_created = 0, chan_ust_created = 0;
1915 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1916
1917 /*
1918 * Don't try to add a context if the session has been started at
1919 * some point in time before. The tracer does not allow it and would
1920 * result in a corrupted trace.
1921 */
1922 if (session->has_been_started) {
1923 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1924 goto end;
1925 }
1926
1927 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1928 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1929 app_ctx_name = ctx->u.app_ctx.ctx_name;
1930 }
1931
1932 switch (domain) {
1933 case LTTNG_DOMAIN_KERNEL:
1934 assert(session->kernel_session);
1935
1936 if (session->kernel_session->channel_count == 0) {
1937 /* Create default channel */
1938 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1939 if (ret != LTTNG_OK) {
1940 goto error;
1941 }
1942 chan_kern_created = 1;
1943 }
1944 /* Add kernel context to kernel tracer */
1945 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1946 if (ret != LTTNG_OK) {
1947 goto error;
1948 }
1949 break;
1950 case LTTNG_DOMAIN_JUL:
1951 case LTTNG_DOMAIN_LOG4J:
1952 {
1953 /*
1954 * Validate channel name.
1955 * If no channel name is given and the domain is JUL or LOG4J,
1956 * set it to the appropriate domain-specific channel name. If
1957 * a name is provided but does not match the expexted channel
1958 * name, return an error.
1959 */
1960 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1961 strcmp(channel_name,
1962 DEFAULT_JUL_CHANNEL_NAME)) {
1963 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1964 goto error;
1965 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1966 strcmp(channel_name,
1967 DEFAULT_LOG4J_CHANNEL_NAME)) {
1968 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1969 goto error;
1970 }
1971 /* break is _not_ missing here. */
1972 }
1973 case LTTNG_DOMAIN_UST:
1974 {
1975 struct ltt_ust_session *usess = session->ust_session;
1976 unsigned int chan_count;
1977
1978 assert(usess);
1979
1980 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1981 if (chan_count == 0) {
1982 struct lttng_channel *attr;
1983 /* Create default channel */
1984 attr = channel_new_default_attr(domain, usess->buffer_type);
1985 if (attr == NULL) {
1986 ret = LTTNG_ERR_FATAL;
1987 goto error;
1988 }
1989
1990 ret = channel_ust_create(usess, attr, usess->buffer_type);
1991 if (ret != LTTNG_OK) {
1992 free(attr);
1993 goto error;
1994 }
1995 channel_attr_destroy(attr);
1996 chan_ust_created = 1;
1997 }
1998
1999 ret = context_ust_add(usess, domain, ctx, channel_name);
2000 free(app_ctx_provider_name);
2001 free(app_ctx_name);
2002 app_ctx_name = NULL;
2003 app_ctx_provider_name = NULL;
2004 if (ret != LTTNG_OK) {
2005 goto error;
2006 }
2007 break;
2008 }
2009 default:
2010 ret = LTTNG_ERR_UND;
2011 goto error;
2012 }
2013
2014 ret = LTTNG_OK;
2015 goto end;
2016
2017 error:
2018 if (chan_kern_created) {
2019 struct ltt_kernel_channel *kchan =
2020 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
2021 session->kernel_session);
2022 /* Created previously, this should NOT fail. */
2023 assert(kchan);
2024 kernel_destroy_channel(kchan);
2025 }
2026
2027 if (chan_ust_created) {
2028 struct ltt_ust_channel *uchan =
2029 trace_ust_find_channel_by_name(
2030 session->ust_session->domain_global.channels,
2031 DEFAULT_CHANNEL_NAME);
2032 /* Created previously, this should NOT fail. */
2033 assert(uchan);
2034 /* Remove from the channel list of the session. */
2035 trace_ust_delete_channel(session->ust_session->domain_global.channels,
2036 uchan);
2037 trace_ust_destroy_channel(uchan);
2038 }
2039 end:
2040 free(app_ctx_provider_name);
2041 free(app_ctx_name);
2042 return ret;
2043 }
2044
2045 static inline bool name_starts_with(const char *name, const char *prefix)
2046 {
2047 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
2048
2049 return !strncmp(name, prefix, max_cmp_len);
2050 }
2051
2052 /* Perform userspace-specific event name validation */
2053 static int validate_ust_event_name(const char *name)
2054 {
2055 int ret = 0;
2056
2057 if (!name) {
2058 ret = -1;
2059 goto end;
2060 }
2061
2062 /*
2063 * Check name against all internal UST event component namespaces used
2064 * by the agents.
2065 */
2066 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2067 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2068 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2069 ret = -1;
2070 }
2071
2072 end:
2073 return ret;
2074 }
2075
2076 /*
2077 * Internal version of cmd_enable_event() with a supplemental
2078 * "internal_event" flag which is used to enable internal events which should
2079 * be hidden from clients. Such events are used in the agent implementation to
2080 * enable the events through which all "agent" events are funeled.
2081 */
2082 static int _cmd_enable_event(struct ltt_session *session,
2083 const struct lttng_domain *domain,
2084 char *channel_name, struct lttng_event *event,
2085 char *filter_expression,
2086 struct lttng_bytecode *filter,
2087 struct lttng_event_exclusion *exclusion,
2088 int wpipe, bool internal_event)
2089 {
2090 int ret = 0, channel_created = 0;
2091 struct lttng_channel *attr = NULL;
2092
2093 assert(session);
2094 assert(event);
2095 assert(channel_name);
2096
2097 /* If we have a filter, we must have its filter expression */
2098 assert(!(!!filter_expression ^ !!filter));
2099
2100 /* Normalize event name as a globbing pattern */
2101 strutils_normalize_star_glob_pattern(event->name);
2102
2103 /* Normalize exclusion names as globbing patterns */
2104 if (exclusion) {
2105 size_t i;
2106
2107 for (i = 0; i < exclusion->count; i++) {
2108 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2109
2110 strutils_normalize_star_glob_pattern(name);
2111 }
2112 }
2113
2114 DBG("Enable event command for event \'%s\'", event->name);
2115
2116 rcu_read_lock();
2117
2118 switch (domain->type) {
2119 case LTTNG_DOMAIN_KERNEL:
2120 {
2121 struct ltt_kernel_channel *kchan;
2122
2123 /*
2124 * If a non-default channel has been created in the
2125 * session, explicitely require that -c chan_name needs
2126 * to be provided.
2127 */
2128 if (session->kernel_session->has_non_default_channel
2129 && channel_name[0] == '\0') {
2130 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2131 goto error;
2132 }
2133
2134 kchan = trace_kernel_get_channel_by_name(channel_name,
2135 session->kernel_session);
2136 if (kchan == NULL) {
2137 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2138 LTTNG_BUFFER_GLOBAL);
2139 if (attr == NULL) {
2140 ret = LTTNG_ERR_FATAL;
2141 goto error;
2142 }
2143 if (lttng_strncpy(attr->name, channel_name,
2144 sizeof(attr->name))) {
2145 ret = LTTNG_ERR_INVALID;
2146 goto error;
2147 }
2148
2149 ret = cmd_enable_channel(session, domain, attr, wpipe);
2150 if (ret != LTTNG_OK) {
2151 goto error;
2152 }
2153 channel_created = 1;
2154 }
2155
2156 /* Get the newly created kernel channel pointer */
2157 kchan = trace_kernel_get_channel_by_name(channel_name,
2158 session->kernel_session);
2159 if (kchan == NULL) {
2160 /* This sould not happen... */
2161 ret = LTTNG_ERR_FATAL;
2162 goto error;
2163 }
2164
2165 switch (event->type) {
2166 case LTTNG_EVENT_ALL:
2167 {
2168 char *filter_expression_a = NULL;
2169 struct lttng_bytecode *filter_a = NULL;
2170
2171 /*
2172 * We need to duplicate filter_expression and filter,
2173 * because ownership is passed to first enable
2174 * event.
2175 */
2176 if (filter_expression) {
2177 filter_expression_a = strdup(filter_expression);
2178 if (!filter_expression_a) {
2179 ret = LTTNG_ERR_FATAL;
2180 goto error;
2181 }
2182 }
2183 if (filter) {
2184 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2185 if (!filter_a) {
2186 free(filter_expression_a);
2187 ret = LTTNG_ERR_FATAL;
2188 goto error;
2189 }
2190 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2191 }
2192 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2193 ret = event_kernel_enable_event(kchan, event,
2194 filter_expression, filter);
2195 /* We have passed ownership */
2196 filter_expression = NULL;
2197 filter = NULL;
2198 if (ret != LTTNG_OK) {
2199 if (channel_created) {
2200 /* Let's not leak a useless channel. */
2201 kernel_destroy_channel(kchan);
2202 }
2203 free(filter_expression_a);
2204 free(filter_a);
2205 goto error;
2206 }
2207 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2208 ret = event_kernel_enable_event(kchan, event,
2209 filter_expression_a, filter_a);
2210 /* We have passed ownership */
2211 filter_expression_a = NULL;
2212 filter_a = NULL;
2213 if (ret != LTTNG_OK) {
2214 goto error;
2215 }
2216 break;
2217 }
2218 case LTTNG_EVENT_PROBE:
2219 case LTTNG_EVENT_USERSPACE_PROBE:
2220 case LTTNG_EVENT_FUNCTION:
2221 case LTTNG_EVENT_FUNCTION_ENTRY:
2222 case LTTNG_EVENT_TRACEPOINT:
2223 ret = event_kernel_enable_event(kchan, event,
2224 filter_expression, filter);
2225 /* We have passed ownership */
2226 filter_expression = NULL;
2227 filter = NULL;
2228 if (ret != LTTNG_OK) {
2229 if (channel_created) {
2230 /* Let's not leak a useless channel. */
2231 kernel_destroy_channel(kchan);
2232 }
2233 goto error;
2234 }
2235 break;
2236 case LTTNG_EVENT_SYSCALL:
2237 ret = event_kernel_enable_event(kchan, event,
2238 filter_expression, filter);
2239 /* We have passed ownership */
2240 filter_expression = NULL;
2241 filter = NULL;
2242 if (ret != LTTNG_OK) {
2243 goto error;
2244 }
2245 break;
2246 default:
2247 ret = LTTNG_ERR_UNK;
2248 goto error;
2249 }
2250
2251 kernel_wait_quiescent();
2252 break;
2253 }
2254 case LTTNG_DOMAIN_UST:
2255 {
2256 struct ltt_ust_channel *uchan;
2257 struct ltt_ust_session *usess = session->ust_session;
2258
2259 assert(usess);
2260
2261 /*
2262 * If a non-default channel has been created in the
2263 * session, explicitely require that -c chan_name needs
2264 * to be provided.
2265 */
2266 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2267 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2268 goto error;
2269 }
2270
2271 /* Get channel from global UST domain */
2272 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2273 channel_name);
2274 if (uchan == NULL) {
2275 /* Create default channel */
2276 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2277 usess->buffer_type);
2278 if (attr == NULL) {
2279 ret = LTTNG_ERR_FATAL;
2280 goto error;
2281 }
2282 if (lttng_strncpy(attr->name, channel_name,
2283 sizeof(attr->name))) {
2284 ret = LTTNG_ERR_INVALID;
2285 goto error;
2286 }
2287
2288 ret = cmd_enable_channel(session, domain, attr, wpipe);
2289 if (ret != LTTNG_OK) {
2290 goto error;
2291 }
2292
2293 /* Get the newly created channel reference back */
2294 uchan = trace_ust_find_channel_by_name(
2295 usess->domain_global.channels, channel_name);
2296 assert(uchan);
2297 }
2298
2299 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2300 /*
2301 * Don't allow users to add UST events to channels which
2302 * are assigned to a userspace subdomain (JUL, Log4J,
2303 * Python, etc.).
2304 */
2305 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2306 goto error;
2307 }
2308
2309 if (!internal_event) {
2310 /*
2311 * Ensure the event name is not reserved for internal
2312 * use.
2313 */
2314 ret = validate_ust_event_name(event->name);
2315 if (ret) {
2316 WARN("Userspace event name %s failed validation.",
2317 event->name);
2318 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2319 goto error;
2320 }
2321 }
2322
2323 /* At this point, the session and channel exist on the tracer */
2324 ret = event_ust_enable_tracepoint(usess, uchan, event,
2325 filter_expression, filter, exclusion,
2326 internal_event);
2327 /* We have passed ownership */
2328 filter_expression = NULL;
2329 filter = NULL;
2330 exclusion = NULL;
2331 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2332 goto already_enabled;
2333 } else if (ret != LTTNG_OK) {
2334 goto error;
2335 }
2336 break;
2337 }
2338 case LTTNG_DOMAIN_LOG4J:
2339 case LTTNG_DOMAIN_JUL:
2340 case LTTNG_DOMAIN_PYTHON:
2341 {
2342 const char *default_event_name, *default_chan_name;
2343 struct agent *agt;
2344 struct lttng_event uevent;
2345 struct lttng_domain tmp_dom;
2346 struct ltt_ust_session *usess = session->ust_session;
2347
2348 assert(usess);
2349
2350 if (!agent_tracing_is_enabled()) {
2351 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2352 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2353 goto error;
2354 }
2355
2356 agt = trace_ust_find_agent(usess, domain->type);
2357 if (!agt) {
2358 agt = agent_create(domain->type);
2359 if (!agt) {
2360 ret = LTTNG_ERR_NOMEM;
2361 goto error;
2362 }
2363 agent_add(agt, usess->agents);
2364 }
2365
2366 /* Create the default tracepoint. */
2367 memset(&uevent, 0, sizeof(uevent));
2368 uevent.type = LTTNG_EVENT_TRACEPOINT;
2369 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2370 default_event_name = event_get_default_agent_ust_name(
2371 domain->type);
2372 if (!default_event_name) {
2373 ret = LTTNG_ERR_FATAL;
2374 goto error;
2375 }
2376 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2377 uevent.name[sizeof(uevent.name) - 1] = '\0';
2378
2379 /*
2380 * The domain type is changed because we are about to enable the
2381 * default channel and event for the JUL domain that are hardcoded.
2382 * This happens in the UST domain.
2383 */
2384 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2385 tmp_dom.type = LTTNG_DOMAIN_UST;
2386
2387 switch (domain->type) {
2388 case LTTNG_DOMAIN_LOG4J:
2389 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2390 break;
2391 case LTTNG_DOMAIN_JUL:
2392 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2393 break;
2394 case LTTNG_DOMAIN_PYTHON:
2395 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2396 break;
2397 default:
2398 /* The switch/case we are in makes this impossible */
2399 assert(0);
2400 }
2401
2402 {
2403 char *filter_expression_copy = NULL;
2404 struct lttng_bytecode *filter_copy = NULL;
2405
2406 if (filter) {
2407 const size_t filter_size = sizeof(
2408 struct lttng_bytecode)
2409 + filter->len;
2410
2411 filter_copy = zmalloc(filter_size);
2412 if (!filter_copy) {
2413 ret = LTTNG_ERR_NOMEM;
2414 goto error;
2415 }
2416 memcpy(filter_copy, filter, filter_size);
2417
2418 filter_expression_copy =
2419 strdup(filter_expression);
2420 if (!filter_expression) {
2421 ret = LTTNG_ERR_NOMEM;
2422 }
2423
2424 if (!filter_expression_copy || !filter_copy) {
2425 free(filter_expression_copy);
2426 free(filter_copy);
2427 goto error;
2428 }
2429 }
2430
2431 ret = cmd_enable_event_internal(session, &tmp_dom,
2432 (char *) default_chan_name,
2433 &uevent, filter_expression_copy,
2434 filter_copy, NULL, wpipe);
2435 }
2436
2437 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2438 goto already_enabled;
2439 } else if (ret != LTTNG_OK) {
2440 goto error;
2441 }
2442
2443 /* The wild card * means that everything should be enabled. */
2444 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2445 ret = event_agent_enable_all(usess, agt, event, filter,
2446 filter_expression);
2447 } else {
2448 ret = event_agent_enable(usess, agt, event, filter,
2449 filter_expression);
2450 }
2451 filter = NULL;
2452 filter_expression = NULL;
2453 if (ret != LTTNG_OK) {
2454 goto error;
2455 }
2456
2457 break;
2458 }
2459 default:
2460 ret = LTTNG_ERR_UND;
2461 goto error;
2462 }
2463
2464 ret = LTTNG_OK;
2465
2466 already_enabled:
2467 error:
2468 free(filter_expression);
2469 free(filter);
2470 free(exclusion);
2471 channel_attr_destroy(attr);
2472 rcu_read_unlock();
2473 return ret;
2474 }
2475
2476 /*
2477 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2478 * We own filter, exclusion, and filter_expression.
2479 */
2480 int cmd_enable_event(struct ltt_session *session,
2481 const struct lttng_domain *domain,
2482 char *channel_name, struct lttng_event *event,
2483 char *filter_expression,
2484 struct lttng_bytecode *filter,
2485 struct lttng_event_exclusion *exclusion,
2486 int wpipe)
2487 {
2488 return _cmd_enable_event(session, domain, channel_name, event,
2489 filter_expression, filter, exclusion, wpipe, false);
2490 }
2491
2492 /*
2493 * Enable an event which is internal to LTTng. An internal should
2494 * never be made visible to clients and are immune to checks such as
2495 * reserved names.
2496 */
2497 static int cmd_enable_event_internal(struct ltt_session *session,
2498 const struct lttng_domain *domain,
2499 char *channel_name, struct lttng_event *event,
2500 char *filter_expression,
2501 struct lttng_bytecode *filter,
2502 struct lttng_event_exclusion *exclusion,
2503 int wpipe)
2504 {
2505 return _cmd_enable_event(session, domain, channel_name, event,
2506 filter_expression, filter, exclusion, wpipe, true);
2507 }
2508
2509 /*
2510 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2511 */
2512 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2513 struct lttng_event **events)
2514 {
2515 int ret;
2516 ssize_t nb_events = 0;
2517
2518 switch (domain) {
2519 case LTTNG_DOMAIN_KERNEL:
2520 nb_events = kernel_list_events(events);
2521 if (nb_events < 0) {
2522 ret = LTTNG_ERR_KERN_LIST_FAIL;
2523 goto error;
2524 }
2525 break;
2526 case LTTNG_DOMAIN_UST:
2527 nb_events = ust_app_list_events(events);
2528 if (nb_events < 0) {
2529 ret = LTTNG_ERR_UST_LIST_FAIL;
2530 goto error;
2531 }
2532 break;
2533 case LTTNG_DOMAIN_LOG4J:
2534 case LTTNG_DOMAIN_JUL:
2535 case LTTNG_DOMAIN_PYTHON:
2536 nb_events = agent_list_events(events, domain);
2537 if (nb_events < 0) {
2538 ret = LTTNG_ERR_UST_LIST_FAIL;
2539 goto error;
2540 }
2541 break;
2542 default:
2543 ret = LTTNG_ERR_UND;
2544 goto error;
2545 }
2546
2547 return nb_events;
2548
2549 error:
2550 /* Return negative value to differentiate return code */
2551 return -ret;
2552 }
2553
2554 /*
2555 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2556 */
2557 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2558 struct lttng_event_field **fields)
2559 {
2560 int ret;
2561 ssize_t nb_fields = 0;
2562
2563 switch (domain) {
2564 case LTTNG_DOMAIN_UST:
2565 nb_fields = ust_app_list_event_fields(fields);
2566 if (nb_fields < 0) {
2567 ret = LTTNG_ERR_UST_LIST_FAIL;
2568 goto error;
2569 }
2570 break;
2571 case LTTNG_DOMAIN_KERNEL:
2572 default: /* fall-through */
2573 ret = LTTNG_ERR_UND;
2574 goto error;
2575 }
2576
2577 return nb_fields;
2578
2579 error:
2580 /* Return negative value to differentiate return code */
2581 return -ret;
2582 }
2583
2584 ssize_t cmd_list_syscalls(struct lttng_event **events)
2585 {
2586 return syscall_table_list(events);
2587 }
2588
2589 /*
2590 * Command LTTNG_START_TRACE processed by the client thread.
2591 *
2592 * Called with session mutex held.
2593 */
2594 int cmd_start_trace(struct ltt_session *session)
2595 {
2596 enum lttng_error_code ret;
2597 unsigned long nb_chan = 0;
2598 struct ltt_kernel_session *ksession;
2599 struct ltt_ust_session *usess;
2600 const bool session_rotated_after_last_stop =
2601 session->rotated_after_last_stop;
2602 const bool session_cleared_after_last_stop =
2603 session->cleared_after_last_stop;
2604
2605 assert(session);
2606
2607 /* Ease our life a bit ;) */
2608 ksession = session->kernel_session;
2609 usess = session->ust_session;
2610
2611 /* Is the session already started? */
2612 if (session->active) {
2613 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2614 /* Perform nothing */
2615 goto end;
2616 }
2617
2618 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2619 !session->current_trace_chunk) {
2620 /*
2621 * A rotation was launched while the session was stopped and
2622 * it has not been completed yet. It is not possible to start
2623 * the session since starting the session here would require a
2624 * rotation from "NULL" to a new trace chunk. That rotation
2625 * would overlap with the ongoing rotation, which is not
2626 * supported.
2627 */
2628 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2629 session->name);
2630 ret = LTTNG_ERR_ROTATION_PENDING;
2631 goto error;
2632 }
2633
2634 /*
2635 * Starting a session without channel is useless since after that it's not
2636 * possible to enable channel thus inform the client.
2637 */
2638 if (usess && usess->domain_global.channels) {
2639 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2640 }
2641 if (ksession) {
2642 nb_chan += ksession->channel_count;
2643 }
2644 if (!nb_chan) {
2645 ret = LTTNG_ERR_NO_CHANNEL;
2646 goto error;
2647 }
2648
2649 session->active = 1;
2650 session->rotated_after_last_stop = false;
2651 session->cleared_after_last_stop = false;
2652 if (session->output_traces && !session->current_trace_chunk) {
2653 if (!session->has_been_started) {
2654 struct lttng_trace_chunk *trace_chunk;
2655
2656 DBG("Creating initial trace chunk of session \"%s\"",
2657 session->name);
2658 trace_chunk = session_create_new_trace_chunk(
2659 session, NULL, NULL, NULL);
2660 if (!trace_chunk) {
2661 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2662 goto error;
2663 }
2664 assert(!session->current_trace_chunk);
2665 ret = session_set_trace_chunk(session, trace_chunk,
2666 NULL);
2667 lttng_trace_chunk_put(trace_chunk);
2668 if (ret) {
2669 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2670 goto error;
2671 }
2672 } else {
2673 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2674 session->name);
2675 /*
2676 * Rotate existing streams into the new chunk.
2677 * This is a "quiet" rotation has no client has
2678 * explicitly requested this operation.
2679 *
2680 * There is also no need to wait for the rotation
2681 * to complete as it will happen immediately. No data
2682 * was produced as the session was stopped, so the
2683 * rotation should happen on reception of the command.
2684 */
2685 ret = cmd_rotate_session(session, NULL, true,
2686 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2687 if (ret != LTTNG_OK) {
2688 goto error;
2689 }
2690 }
2691 }
2692
2693 /* Kernel tracing */
2694 if (ksession != NULL) {
2695 DBG("Start kernel tracing session %s", session->name);
2696 ret = start_kernel_session(ksession);
2697 if (ret != LTTNG_OK) {
2698 goto error;
2699 }
2700 }
2701
2702 /* Flag session that trace should start automatically */
2703 if (usess) {
2704 int int_ret = ust_app_start_trace_all(usess);
2705
2706 if (int_ret < 0) {
2707 ret = LTTNG_ERR_UST_START_FAIL;
2708 goto error;
2709 }
2710 }
2711
2712 /*
2713 * Open a packet in every stream of the session to ensure that viewers
2714 * can correctly identify the boundaries of the periods during which
2715 * tracing was active for this session.
2716 */
2717 ret = session_open_packets(session);
2718 if (ret != LTTNG_OK) {
2719 goto error;
2720 }
2721
2722 /*
2723 * Clear the flag that indicates that a rotation was done while the
2724 * session was stopped.
2725 */
2726 session->rotated_after_last_stop = false;
2727
2728 if (session->rotate_timer_period) {
2729 int int_ret = timer_session_rotation_schedule_timer_start(
2730 session, session->rotate_timer_period);
2731
2732 if (int_ret < 0) {
2733 ERR("Failed to enable rotate timer");
2734 ret = LTTNG_ERR_UNK;
2735 goto error;
2736 }
2737 }
2738
2739 ret = LTTNG_OK;
2740
2741 error:
2742 if (ret == LTTNG_OK) {
2743 /* Flag this after a successful start. */
2744 session->has_been_started |= 1;
2745 } else {
2746 session->active = 0;
2747 /* Restore initial state on error. */
2748 session->rotated_after_last_stop =
2749 session_rotated_after_last_stop;
2750 session->cleared_after_last_stop =
2751 session_cleared_after_last_stop;
2752 }
2753 end:
2754 return ret;
2755 }
2756
2757 /*
2758 * Command LTTNG_STOP_TRACE processed by the client thread.
2759 */
2760 int cmd_stop_trace(struct ltt_session *session)
2761 {
2762 int ret;
2763 struct ltt_kernel_session *ksession;
2764 struct ltt_ust_session *usess;
2765
2766 assert(session);
2767
2768 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2769 /* Short cut */
2770 ksession = session->kernel_session;
2771 usess = session->ust_session;
2772
2773 /* Session is not active. Skip everythong and inform the client. */
2774 if (!session->active) {
2775 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2776 goto error;
2777 }
2778
2779 ret = stop_kernel_session(ksession);
2780 if (ret != LTTNG_OK) {
2781 goto error;
2782 }
2783
2784 if (usess && usess->active) {
2785 ret = ust_app_stop_trace_all(usess);
2786 if (ret < 0) {
2787 ret = LTTNG_ERR_UST_STOP_FAIL;
2788 goto error;
2789 }
2790 }
2791
2792 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2793 session->id);
2794 /* Flag inactive after a successful stop. */
2795 session->active = 0;
2796 ret = LTTNG_OK;
2797
2798 error:
2799 return ret;
2800 }
2801
2802 /*
2803 * Set the base_path of the session only if subdir of a control uris is set.
2804 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2805 */
2806 static int set_session_base_path_from_uris(struct ltt_session *session,
2807 size_t nb_uri,
2808 struct lttng_uri *uris)
2809 {
2810 int ret;
2811 size_t i;
2812
2813 for (i = 0; i < nb_uri; i++) {
2814 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2815 uris[i].subdir[0] == '\0') {
2816 /* Not interested in these URIs */
2817 continue;
2818 }
2819
2820 if (session->base_path != NULL) {
2821 free(session->base_path);
2822 session->base_path = NULL;
2823 }
2824
2825 /* Set session base_path */
2826 session->base_path = strdup(uris[i].subdir);
2827 if (!session->base_path) {
2828 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2829 uris[i].subdir, session->name);
2830 ret = LTTNG_ERR_NOMEM;
2831 goto error;
2832 }
2833 DBG2("Setting base path \"%s\" for session \"%s\"",
2834 session->base_path, session->name);
2835 }
2836 ret = LTTNG_OK;
2837 error:
2838 return ret;
2839 }
2840
2841 /*
2842 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2843 */
2844 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2845 struct lttng_uri *uris)
2846 {
2847 int ret, i;
2848 struct ltt_kernel_session *ksess = session->kernel_session;
2849 struct ltt_ust_session *usess = session->ust_session;
2850
2851 assert(session);
2852 assert(uris);
2853 assert(nb_uri > 0);
2854
2855 /* Can't set consumer URI if the session is active. */
2856 if (session->active) {
2857 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2858 goto error;
2859 }
2860
2861 /*
2862 * Set the session base path if any. This is done inside
2863 * cmd_set_consumer_uri to preserve backward compatibility of the
2864 * previous session creation api vs the session descriptor api.
2865 */
2866 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2867 if (ret != LTTNG_OK) {
2868 goto error;
2869 }
2870
2871 /* Set the "global" consumer URIs */
2872 for (i = 0; i < nb_uri; i++) {
2873 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2874 LTTNG_DOMAIN_NONE);
2875 if (ret != LTTNG_OK) {
2876 goto error;
2877 }
2878 }
2879
2880 /* Set UST session URIs */
2881 if (session->ust_session) {
2882 for (i = 0; i < nb_uri; i++) {
2883 ret = add_uri_to_consumer(session,
2884 session->ust_session->consumer,
2885 &uris[i], LTTNG_DOMAIN_UST);
2886 if (ret != LTTNG_OK) {
2887 goto error;
2888 }
2889 }
2890 }
2891
2892 /* Set kernel session URIs */
2893 if (session->kernel_session) {
2894 for (i = 0; i < nb_uri; i++) {
2895 ret = add_uri_to_consumer(session,
2896 session->kernel_session->consumer,
2897 &uris[i], LTTNG_DOMAIN_KERNEL);
2898 if (ret != LTTNG_OK) {
2899 goto error;
2900 }
2901 }
2902 }
2903
2904 /*
2905 * Make sure to set the session in output mode after we set URI since a
2906 * session can be created without URL (thus flagged in no output mode).
2907 */
2908 session->output_traces = 1;
2909 if (ksess) {
2910 ksess->output_traces = 1;
2911 }
2912
2913 if (usess) {
2914 usess->output_traces = 1;
2915 }
2916
2917 /* All good! */
2918 ret = LTTNG_OK;
2919
2920 error:
2921 return ret;
2922 }
2923
2924 static
2925 enum lttng_error_code set_session_output_from_descriptor(
2926 struct ltt_session *session,
2927 const struct lttng_session_descriptor *descriptor)
2928 {
2929 int ret;
2930 enum lttng_error_code ret_code = LTTNG_OK;
2931 enum lttng_session_descriptor_type session_type =
2932 lttng_session_descriptor_get_type(descriptor);
2933 enum lttng_session_descriptor_output_type output_type =
2934 lttng_session_descriptor_get_output_type(descriptor);
2935 struct lttng_uri uris[2] = {};
2936 size_t uri_count = 0;
2937
2938 switch (output_type) {
2939 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2940 goto end;
2941 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2942 lttng_session_descriptor_get_local_output_uri(descriptor,
2943 &uris[0]);
2944 uri_count = 1;
2945 break;
2946 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2947 lttng_session_descriptor_get_network_output_uris(descriptor,
2948 &uris[0], &uris[1]);
2949 uri_count = 2;
2950 break;
2951 default:
2952 ret_code = LTTNG_ERR_INVALID;
2953 goto end;
2954 }
2955
2956 switch (session_type) {
2957 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2958 {
2959 struct snapshot_output *new_output = NULL;
2960
2961 new_output = snapshot_output_alloc();
2962 if (!new_output) {
2963 ret_code = LTTNG_ERR_NOMEM;
2964 goto end;
2965 }
2966
2967 ret = snapshot_output_init_with_uri(session,
2968 DEFAULT_SNAPSHOT_MAX_SIZE,
2969 NULL, uris, uri_count, session->consumer,
2970 new_output, &session->snapshot);
2971 if (ret < 0) {
2972 ret_code = (ret == -ENOMEM) ?
2973 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2974 snapshot_output_destroy(new_output);
2975 goto end;
2976 }
2977 snapshot_add_output(&session->snapshot, new_output);
2978 break;
2979 }
2980 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2981 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2982 {
2983 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2984 break;
2985 }
2986 default:
2987 ret_code = LTTNG_ERR_INVALID;
2988 goto end;
2989 }
2990 end:
2991 return ret_code;
2992 }
2993
2994 static
2995 enum lttng_error_code cmd_create_session_from_descriptor(
2996 struct lttng_session_descriptor *descriptor,
2997 const lttng_sock_cred *creds,
2998 const char *home_path)
2999 {
3000 int ret;
3001 enum lttng_error_code ret_code;
3002 const char *session_name;
3003 struct ltt_session *new_session = NULL;
3004 enum lttng_session_descriptor_status descriptor_status;
3005
3006 session_lock_list();
3007 if (home_path) {
3008 if (*home_path != '/') {
3009 ERR("Home path provided by client is not absolute");
3010 ret_code = LTTNG_ERR_INVALID;
3011 goto end;
3012 }
3013 }
3014
3015 descriptor_status = lttng_session_descriptor_get_session_name(
3016 descriptor, &session_name);
3017 switch (descriptor_status) {
3018 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3019 break;
3020 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3021 session_name = NULL;
3022 break;
3023 default:
3024 ret_code = LTTNG_ERR_INVALID;
3025 goto end;
3026 }
3027
3028 ret_code = session_create(session_name, creds->uid, creds->gid,
3029 &new_session);
3030 if (ret_code != LTTNG_OK) {
3031 goto end;
3032 }
3033
3034 if (!session_name) {
3035 ret = lttng_session_descriptor_set_session_name(descriptor,
3036 new_session->name);
3037 if (ret) {
3038 ret_code = LTTNG_ERR_SESSION_FAIL;
3039 goto end;
3040 }
3041 }
3042
3043 if (!lttng_session_descriptor_is_output_destination_initialized(
3044 descriptor)) {
3045 /*
3046 * Only include the session's creation time in the output
3047 * destination if the name of the session itself was
3048 * not auto-generated.
3049 */
3050 ret_code = lttng_session_descriptor_set_default_output(
3051 descriptor,
3052 session_name ? &new_session->creation_time : NULL,
3053 home_path);
3054 if (ret_code != LTTNG_OK) {
3055 goto end;
3056 }
3057 } else {
3058 new_session->has_user_specified_directory =
3059 lttng_session_descriptor_has_output_directory(
3060 descriptor);
3061 }
3062
3063 switch (lttng_session_descriptor_get_type(descriptor)) {
3064 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3065 new_session->snapshot_mode = 1;
3066 break;
3067 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3068 new_session->live_timer =
3069 lttng_session_descriptor_live_get_timer_interval(
3070 descriptor);
3071 break;
3072 default:
3073 break;
3074 }
3075
3076 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3077 if (ret_code != LTTNG_OK) {
3078 goto end;
3079 }
3080 new_session->consumer->enabled = 1;
3081 ret_code = LTTNG_OK;
3082 end:
3083 /* Release reference provided by the session_create function. */
3084 session_put(new_session);
3085 if (ret_code != LTTNG_OK && new_session) {
3086 /* Release the global reference on error. */
3087 session_destroy(new_session);
3088 }
3089 session_unlock_list();
3090 return ret_code;
3091 }
3092
3093 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3094 struct lttng_session_descriptor **return_descriptor)
3095 {
3096 int ret;
3097 size_t payload_size;
3098 struct lttng_dynamic_buffer payload;
3099 struct lttng_buffer_view home_dir_view;
3100 struct lttng_buffer_view session_descriptor_view;
3101 struct lttng_session_descriptor *session_descriptor = NULL;
3102 enum lttng_error_code ret_code;
3103
3104 lttng_dynamic_buffer_init(&payload);
3105 if (cmd_ctx->lsm.u.create_session.home_dir_size >=
3106 LTTNG_PATH_MAX) {
3107 ret_code = LTTNG_ERR_INVALID;
3108 goto error;
3109 }
3110 if (cmd_ctx->lsm.u.create_session.session_descriptor_size >
3111 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3112 ret_code = LTTNG_ERR_INVALID;
3113 goto error;
3114 }
3115
3116 payload_size = cmd_ctx->lsm.u.create_session.home_dir_size +
3117 cmd_ctx->lsm.u.create_session.session_descriptor_size;
3118 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3119 if (ret) {
3120 ret_code = LTTNG_ERR_NOMEM;
3121 goto error;
3122 }
3123
3124 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3125 if (ret <= 0) {
3126 ERR("Reception of session descriptor failed, aborting.");
3127 ret_code = LTTNG_ERR_SESSION_FAIL;
3128 goto error;
3129 }
3130
3131 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3132 &payload,
3133 0,
3134 cmd_ctx->lsm.u.create_session.home_dir_size);
3135 if (cmd_ctx->lsm.u.create_session.home_dir_size > 0 &&
3136 !lttng_buffer_view_is_valid(&home_dir_view)) {
3137 ERR("Invalid payload in \"create session\" command: buffer too short to contain home directory");
3138 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3139 goto error;
3140 }
3141
3142 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3143 &payload,
3144 cmd_ctx->lsm.u.create_session.home_dir_size,
3145 cmd_ctx->lsm.u.create_session.session_descriptor_size);
3146 if (!lttng_buffer_view_is_valid(&session_descriptor_view)) {
3147 ERR("Invalid payload in \"create session\" command: buffer too short to contain session descriptor");
3148 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3149 goto error;
3150 }
3151
3152 ret = lttng_session_descriptor_create_from_buffer(
3153 &session_descriptor_view, &session_descriptor);
3154 if (ret < 0) {
3155 ERR("Failed to create session descriptor from payload of \"create session\" command");
3156 ret_code = LTTNG_ERR_INVALID;
3157 goto error;
3158 }
3159
3160 /*
3161 * Sets the descriptor's auto-generated properties (name, output) if
3162 * needed.
3163 */
3164 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3165 &cmd_ctx->creds,
3166 home_dir_view.size ? home_dir_view.data : NULL);
3167 if (ret_code != LTTNG_OK) {
3168 goto error;
3169 }
3170
3171 ret_code = LTTNG_OK;
3172 *return_descriptor = session_descriptor;
3173 session_descriptor = NULL;
3174 error:
3175 lttng_dynamic_buffer_reset(&payload);
3176 lttng_session_descriptor_destroy(session_descriptor);
3177 return ret_code;
3178 }
3179
3180 static
3181 void cmd_destroy_session_reply(const struct ltt_session *session,
3182 void *_reply_context)
3183 {
3184 int ret;
3185 ssize_t comm_ret;
3186 const struct cmd_destroy_session_reply_context *reply_context =
3187 _reply_context;
3188 struct lttng_dynamic_buffer payload;
3189 struct lttcomm_session_destroy_command_header cmd_header;
3190 struct lttng_trace_archive_location *location = NULL;
3191 struct lttcomm_lttng_msg llm = {
3192 .cmd_type = LTTNG_DESTROY_SESSION,
3193 .ret_code = reply_context->destruction_status,
3194 .pid = UINT32_MAX,
3195 .cmd_header_size =
3196 sizeof(struct lttcomm_session_destroy_command_header),
3197 .data_size = 0,
3198 };
3199 size_t payload_size_before_location;
3200
3201 lttng_dynamic_buffer_init(&payload);
3202
3203 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3204 if (ret) {
3205 ERR("Failed to append session destruction message");
3206 goto error;
3207 }
3208
3209 cmd_header.rotation_state =
3210 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3211 session->rotation_state :
3212 LTTNG_ROTATION_STATE_NO_ROTATION);
3213 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3214 sizeof(cmd_header));
3215 if (ret) {
3216 ERR("Failed to append session destruction command header");
3217 goto error;
3218 }
3219
3220 if (!reply_context->implicit_rotation_on_destroy) {
3221 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3222 session->name);
3223 goto send_reply;
3224 }
3225 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3226 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3227 session->name);
3228 goto send_reply;
3229 }
3230
3231 location = session_get_trace_archive_location(session);
3232 if (!location) {
3233 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3234 session->name);
3235 goto error;
3236 }
3237
3238 payload_size_before_location = payload.size;
3239 comm_ret = lttng_trace_archive_location_serialize(location,
3240 &payload);
3241 if (comm_ret < 0) {
3242 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3243 session->name);
3244 goto error;
3245 }
3246 /* Update the message to indicate the location's length. */
3247 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3248 payload.size - payload_size_before_location;
3249 send_reply:
3250 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3251 payload.data, payload.size);
3252 if (comm_ret != (ssize_t) payload.size) {
3253 ERR("Failed to send result of the destruction of session \"%s\" to client",
3254 session->name);
3255 }
3256 error:
3257 ret = close(reply_context->reply_sock_fd);
3258 if (ret) {
3259 PERROR("Failed to close client socket in deferred session destroy reply");
3260 }
3261 lttng_dynamic_buffer_reset(&payload);
3262 free(_reply_context);
3263 }
3264
3265 /*
3266 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3267 *
3268 * Called with session lock held.
3269 */
3270 int cmd_destroy_session(struct ltt_session *session,
3271 struct notification_thread_handle *notification_thread_handle,
3272 int *sock_fd)
3273 {
3274 int ret;
3275 enum lttng_error_code destruction_last_error = LTTNG_OK;
3276 struct cmd_destroy_session_reply_context *reply_context = NULL;
3277
3278 if (sock_fd) {
3279 reply_context = zmalloc(sizeof(*reply_context));
3280 if (!reply_context) {
3281 ret = LTTNG_ERR_NOMEM;
3282 goto end;
3283 }
3284 reply_context->reply_sock_fd = *sock_fd;
3285 }
3286
3287 /* Safety net */
3288 assert(session);
3289
3290 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3291 session->id);
3292 if (session->active) {
3293 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3294 session->name);
3295 ret = cmd_stop_trace(session);
3296 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3297 /* Carry on with the destruction of the session. */
3298 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3299 session->name, lttng_strerror(-ret));
3300 destruction_last_error = ret;
3301 }
3302 }
3303
3304 if (session->rotation_schedule_timer_enabled) {
3305 if (timer_session_rotation_schedule_timer_stop(
3306 session)) {
3307 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3308 session->name);
3309 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3310 }
3311 }
3312
3313 if (session->rotate_size) {
3314 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3315 session->rotate_size = 0;
3316 }
3317
3318 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3319 /*
3320 * Perform a last rotation on destruction if rotations have
3321 * occurred during the session's lifetime.
3322 */
3323 ret = cmd_rotate_session(session, NULL, false,
3324 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3325 if (ret != LTTNG_OK) {
3326 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3327 session->name, lttng_strerror(-ret));
3328 destruction_last_error = -ret;
3329 }
3330 if (reply_context) {
3331 reply_context->implicit_rotation_on_destroy = true;
3332 }
3333 } else if (session->has_been_started && session->current_trace_chunk) {
3334 /*
3335 * The user has not triggered a session rotation. However, to
3336 * ensure all data has been consumed, the session is rotated
3337 * to a 'null' trace chunk before it is destroyed.
3338 *
3339 * This is a "quiet" rotation meaning that no notification is
3340 * emitted and no renaming of the current trace chunk takes
3341 * place.
3342 */
3343 ret = cmd_rotate_session(session, NULL, true,
3344 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3345 /*
3346 * Rotation operations may not be supported by the kernel
3347 * tracer. Hence, do not consider this implicit rotation as
3348 * a session destruction error. The library has already stopped
3349 * the session and waited for pending data; there is nothing
3350 * left to do but complete the destruction of the session.
3351 */
3352 if (ret != LTTNG_OK &&
3353 ret != -LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL) {
3354 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3355 session->name, lttng_strerror(ret));
3356 destruction_last_error = -ret;
3357 }
3358 }
3359
3360 if (session->shm_path[0]) {
3361 /*
3362 * When a session is created with an explicit shm_path,
3363 * the consumer daemon will create its shared memory files
3364 * at that location and will *not* unlink them. This is normal
3365 * as the intention of that feature is to make it possible
3366 * to retrieve the content of those files should a crash occur.
3367 *
3368 * To ensure the content of those files can be used, the
3369 * sessiond daemon will replicate the content of the metadata
3370 * cache in a metadata file.
3371 *
3372 * On clean-up, it is expected that the consumer daemon will
3373 * unlink the shared memory files and that the session daemon
3374 * will unlink the metadata file. Then, the session's directory
3375 * in the shm path can be removed.
3376 *
3377 * Unfortunately, a flaw in the design of the sessiond's and
3378 * consumerd's tear down of channels makes it impossible to
3379 * determine when the sessiond _and_ the consumerd have both
3380 * destroyed their representation of a channel. For one, the
3381 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3382 * callbacks in both daemons.
3383 *
3384 * However, it is also impossible for the sessiond to know when
3385 * the consumer daemon is done destroying its channel(s) since
3386 * it occurs as a reaction to the closing of the channel's file
3387 * descriptor. There is no resulting communication initiated
3388 * from the consumerd to the sessiond to confirm that the
3389 * operation is completed (and was successful).
3390 *
3391 * Until this is all fixed, the session daemon checks for the
3392 * removal of the session's shm path which makes it possible
3393 * to safely advertise a session as having been destroyed.
3394 *
3395 * Prior to this fix, it was not possible to reliably save
3396 * a session making use of the --shm-path option, destroy it,
3397 * and load it again. This is because the creation of the
3398 * session would fail upon seeing the session's shm path
3399 * already in existence.
3400 *
3401 * Note that none of the error paths in the check for the
3402 * directory's existence return an error. This is normal
3403 * as there isn't much that can be done. The session will
3404 * be destroyed properly, except that we can't offer the
3405 * guarantee that the same session can be re-created.
3406 */
3407 current_completion_handler = &destroy_completion_handler.handler;
3408 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3409 session->shm_path,
3410 sizeof(destroy_completion_handler.shm_path));
3411 assert(!ret);
3412 }
3413
3414 /*
3415 * The session is destroyed. However, note that the command context
3416 * still holds a reference to the session, thus delaying its destruction
3417 * _at least_ up to the point when that reference is released.
3418 */
3419 session_destroy(session);
3420 if (reply_context) {
3421 reply_context->destruction_status = destruction_last_error;
3422 ret = session_add_destroy_notifier(session,
3423 cmd_destroy_session_reply,
3424 (void *) reply_context);
3425 if (ret) {
3426 ret = LTTNG_ERR_FATAL;
3427 goto end;
3428 } else {
3429 *sock_fd = -1;
3430 }
3431 }
3432 ret = LTTNG_OK;
3433 end:
3434 return ret;
3435 }
3436
3437 /*
3438 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3439 */
3440 int cmd_register_consumer(struct ltt_session *session,
3441 enum lttng_domain_type domain, const char *sock_path,
3442 struct consumer_data *cdata)
3443 {
3444 int ret, sock;
3445 struct consumer_socket *socket = NULL;
3446
3447 assert(session);
3448 assert(cdata);
3449 assert(sock_path);
3450
3451 switch (domain) {
3452 case LTTNG_DOMAIN_KERNEL:
3453 {
3454 struct ltt_kernel_session *ksess = session->kernel_session;
3455
3456 assert(ksess);
3457
3458 /* Can't register a consumer if there is already one */
3459 if (ksess->consumer_fds_sent != 0) {
3460 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3461 goto error;
3462 }
3463
3464 sock = lttcomm_connect_unix_sock(sock_path);
3465 if (sock < 0) {
3466 ret = LTTNG_ERR_CONNECT_FAIL;
3467 goto error;
3468 }
3469 cdata->cmd_sock = sock;
3470
3471 socket = consumer_allocate_socket(&cdata->cmd_sock);
3472 if (socket == NULL) {
3473 ret = close(sock);
3474 if (ret < 0) {
3475 PERROR("close register consumer");
3476 }
3477 cdata->cmd_sock = -1;
3478 ret = LTTNG_ERR_FATAL;
3479 goto error;
3480 }
3481
3482 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3483 if (socket->lock == NULL) {
3484 PERROR("zmalloc pthread mutex");
3485 ret = LTTNG_ERR_FATAL;
3486 goto error;
3487 }
3488 pthread_mutex_init(socket->lock, NULL);
3489 socket->registered = 1;
3490
3491 rcu_read_lock();
3492 consumer_add_socket(socket, ksess->consumer);
3493 rcu_read_unlock();
3494
3495 pthread_mutex_lock(&cdata->pid_mutex);
3496 cdata->pid = -1;
3497 pthread_mutex_unlock(&cdata->pid_mutex);
3498
3499 break;
3500 }
3501 default:
3502 /* TODO: Userspace tracing */
3503 ret = LTTNG_ERR_UND;
3504 goto error;
3505 }
3506
3507 return LTTNG_OK;
3508
3509 error:
3510 if (socket) {
3511 consumer_destroy_socket(socket);
3512 }
3513 return ret;
3514 }
3515
3516 /*
3517 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3518 */
3519 ssize_t cmd_list_domains(struct ltt_session *session,
3520 struct lttng_domain **domains)
3521 {
3522 int ret, index = 0;
3523 ssize_t nb_dom = 0;
3524 struct agent *agt;
3525 struct lttng_ht_iter iter;
3526
3527 if (session->kernel_session != NULL) {
3528 DBG3("Listing domains found kernel domain");
3529 nb_dom++;
3530 }
3531
3532 if (session->ust_session != NULL) {
3533 DBG3("Listing domains found UST global domain");
3534 nb_dom++;
3535
3536 rcu_read_lock();
3537 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3538 agt, node.node) {
3539 if (agt->being_used) {
3540 nb_dom++;
3541 }
3542 }
3543 rcu_read_unlock();
3544 }
3545
3546 if (!nb_dom) {
3547 goto end;
3548 }
3549
3550 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3551 if (*domains == NULL) {
3552 ret = LTTNG_ERR_FATAL;
3553 goto error;
3554 }
3555
3556 if (session->kernel_session != NULL) {
3557 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3558
3559 /* Kernel session buffer type is always GLOBAL */
3560 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3561
3562 index++;
3563 }
3564
3565 if (session->ust_session != NULL) {
3566 (*domains)[index].type = LTTNG_DOMAIN_UST;
3567 (*domains)[index].buf_type = session->ust_session->buffer_type;
3568 index++;
3569
3570 rcu_read_lock();
3571 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3572 agt, node.node) {
3573 if (agt->being_used) {
3574 (*domains)[index].type = agt->domain;
3575 (*domains)[index].buf_type = session->ust_session->buffer_type;
3576 index++;
3577 }
3578 }
3579 rcu_read_unlock();
3580 }
3581 end:
3582 return nb_dom;
3583
3584 error:
3585 /* Return negative value to differentiate return code */
3586 return -ret;
3587 }
3588
3589
3590 /*
3591 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3592 */
3593 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3594 struct ltt_session *session, struct lttng_channel **channels)
3595 {
3596 ssize_t nb_chan = 0, payload_size = 0, ret;
3597
3598 switch (domain) {
3599 case LTTNG_DOMAIN_KERNEL:
3600 if (session->kernel_session != NULL) {
3601 nb_chan = session->kernel_session->channel_count;
3602 }
3603 DBG3("Number of kernel channels %zd", nb_chan);
3604 if (nb_chan <= 0) {
3605 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3606 goto end;
3607 }
3608 break;
3609 case LTTNG_DOMAIN_UST:
3610 if (session->ust_session != NULL) {
3611 rcu_read_lock();
3612 nb_chan = lttng_ht_get_count(
3613 session->ust_session->domain_global.channels);
3614 rcu_read_unlock();
3615 }
3616 DBG3("Number of UST global channels %zd", nb_chan);
3617 if (nb_chan < 0) {
3618 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3619 goto end;
3620 }
3621 break;
3622 default:
3623 ret = -LTTNG_ERR_UND;
3624 goto end;
3625 }
3626
3627 if (nb_chan > 0) {
3628 const size_t channel_size = sizeof(struct lttng_channel) +
3629 sizeof(struct lttng_channel_extended);
3630 struct lttng_channel_extended *channel_exts;
3631
3632 payload_size = nb_chan * channel_size;
3633 *channels = zmalloc(payload_size);
3634 if (*channels == NULL) {
3635 ret = -LTTNG_ERR_FATAL;
3636 goto end;
3637 }
3638
3639 channel_exts = ((void *) *channels) +
3640 (nb_chan * sizeof(struct lttng_channel));
3641 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3642 if (ret != LTTNG_OK) {
3643 free(*channels);
3644 *channels = NULL;
3645 goto end;
3646 }
3647 } else {
3648 *channels = NULL;
3649 }
3650
3651 ret = payload_size;
3652 end:
3653 return ret;
3654 }
3655
3656 /*
3657 * Command LTTNG_LIST_EVENTS processed by the client thread.
3658 */
3659 ssize_t cmd_list_events(enum lttng_domain_type domain,
3660 struct ltt_session *session, char *channel_name,
3661 struct lttng_payload *payload)
3662 {
3663 int ret = 0;
3664 ssize_t nb_events = 0;
3665 struct lttcomm_event_command_header cmd_header = {};
3666 const size_t cmd_header_offset = payload->buffer.size;
3667
3668 ret = lttng_dynamic_buffer_append(
3669 &payload->buffer, &cmd_header, sizeof(cmd_header));
3670 if (ret) {
3671 ret = LTTNG_ERR_NOMEM;
3672 goto error;
3673 }
3674
3675 switch (domain) {
3676 case LTTNG_DOMAIN_KERNEL:
3677 if (session->kernel_session != NULL) {
3678 nb_events = list_lttng_kernel_events(channel_name,
3679 session->kernel_session, payload);
3680 }
3681 break;
3682 case LTTNG_DOMAIN_UST:
3683 {
3684 if (session->ust_session != NULL) {
3685 nb_events = list_lttng_ust_global_events(channel_name,
3686 &session->ust_session->domain_global,
3687 payload);
3688 }
3689 break;
3690 }
3691 case LTTNG_DOMAIN_LOG4J:
3692 case LTTNG_DOMAIN_JUL:
3693 case LTTNG_DOMAIN_PYTHON:
3694 if (session->ust_session) {
3695 struct lttng_ht_iter iter;
3696 struct agent *agt;
3697
3698 rcu_read_lock();
3699 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3700 &iter.iter, agt, node.node) {
3701 if (agt->domain == domain) {
3702 nb_events = list_lttng_agent_events(
3703 agt, payload);
3704 break;
3705 }
3706 }
3707 rcu_read_unlock();
3708 }
3709 break;
3710 default:
3711 ret = LTTNG_ERR_UND;
3712 goto error;
3713 }
3714
3715 ((struct lttcomm_event_command_header *) (payload->buffer.data +
3716 cmd_header_offset))->nb_events = (uint32_t) nb_events;
3717
3718 return nb_events;
3719
3720 error:
3721 /* Return negative value to differentiate return code */
3722 return -ret;
3723 }
3724
3725 /*
3726 * Using the session list, filled a lttng_session array to send back to the
3727 * client for session listing.
3728 *
3729 * The session list lock MUST be acquired before calling this function. Use
3730 * session_lock_list() and session_unlock_list().
3731 */
3732 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3733 size_t session_count, uid_t uid, gid_t gid)
3734 {
3735 int ret;
3736 unsigned int i = 0;
3737 struct ltt_session *session;
3738 struct ltt_session_list *list = session_get_list();
3739 struct lttng_session_extended *extended =
3740 (typeof(extended)) (&sessions[session_count]);
3741
3742 DBG("Getting all available session for UID %d GID %d",
3743 uid, gid);
3744 /*
3745 * Iterate over session list and append data after the control struct in
3746 * the buffer.
3747 */
3748 cds_list_for_each_entry(session, &list->head, list) {
3749 if (!session_get(session)) {
3750 continue;
3751 }
3752 /*
3753 * Only list the sessions the user can control.
3754 */
3755 if (!session_access_ok(session, uid) ||
3756 session->destroyed) {
3757 session_put(session);
3758 continue;
3759 }
3760
3761 struct ltt_kernel_session *ksess = session->kernel_session;
3762 struct ltt_ust_session *usess = session->ust_session;
3763
3764 if (session->consumer->type == CONSUMER_DST_NET ||
3765 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3766 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3767 ret = build_network_session_path(sessions[i].path,
3768 sizeof(sessions[i].path), session);
3769 } else {
3770 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3771 session->consumer->dst.session_root_path);
3772 }
3773 if (ret < 0) {
3774 PERROR("snprintf session path");
3775 session_put(session);
3776 continue;
3777 }
3778
3779 strncpy(sessions[i].name, session->name, NAME_MAX);
3780 sessions[i].name[NAME_MAX - 1] = '\0';
3781 sessions[i].enabled = session->active;
3782 sessions[i].snapshot_mode = session->snapshot_mode;
3783 sessions[i].live_timer_interval = session->live_timer;
3784 extended[i].creation_time.value = (uint64_t) session->creation_time;
3785 extended[i].creation_time.is_set = 1;
3786 i++;
3787 session_put(session);
3788 }
3789 }
3790
3791 /*
3792 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3793 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3794 */
3795 int cmd_data_pending(struct ltt_session *session)
3796 {
3797 int ret;
3798 struct ltt_kernel_session *ksess = session->kernel_session;
3799 struct ltt_ust_session *usess = session->ust_session;
3800
3801 assert(session);
3802
3803 DBG("Data pending for session %s", session->name);
3804
3805 /* Session MUST be stopped to ask for data availability. */
3806 if (session->active) {
3807 ret = LTTNG_ERR_SESSION_STARTED;
3808 goto error;
3809 } else {
3810 /*
3811 * If stopped, just make sure we've started before else the above call
3812 * will always send that there is data pending.
3813 *
3814 * The consumer assumes that when the data pending command is received,
3815 * the trace has been started before or else no output data is written
3816 * by the streams which is a condition for data pending. So, this is
3817 * *VERY* important that we don't ask the consumer before a start
3818 * trace.
3819 */
3820 if (!session->has_been_started) {
3821 ret = 0;
3822 goto error;
3823 }
3824 }
3825
3826 /* A rotation is still pending, we have to wait. */
3827 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3828 DBG("Rotate still pending for session %s", session->name);
3829 ret = 1;
3830 goto error;
3831 }
3832
3833 if (ksess && ksess->consumer) {
3834 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3835 if (ret == 1) {
3836 /* Data is still being extracted for the kernel. */
3837 goto error;
3838 }
3839 }
3840
3841 if (usess && usess->consumer) {
3842 ret = consumer_is_data_pending(usess->id, usess->consumer);
3843 if (ret == 1) {
3844 /* Data is still being extracted for the kernel. */
3845 goto error;
3846 }
3847 }
3848
3849 /* Data is ready to be read by a viewer */
3850 ret = 0;
3851
3852 error:
3853 return ret;
3854 }
3855
3856 /*
3857 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3858 *
3859 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3860 */
3861 int cmd_snapshot_add_output(struct ltt_session *session,
3862 const struct lttng_snapshot_output *output, uint32_t *id)
3863 {
3864 int ret;
3865 struct snapshot_output *new_output;
3866
3867 assert(session);
3868 assert(output);
3869
3870 DBG("Cmd snapshot add output for session %s", session->name);
3871
3872 /*
3873 * Can't create an output if the session is not set in no-output mode.
3874 */
3875 if (session->output_traces) {
3876 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3877 goto error;
3878 }
3879
3880 if (session->has_non_mmap_channel) {
3881 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3882 goto error;
3883 }
3884
3885 /* Only one output is allowed until we have the "tee" feature. */
3886 if (session->snapshot.nb_output == 1) {
3887 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3888 goto error;
3889 }
3890
3891 new_output = snapshot_output_alloc();
3892 if (!new_output) {
3893 ret = LTTNG_ERR_NOMEM;
3894 goto error;
3895 }
3896
3897 ret = snapshot_output_init(session, output->max_size, output->name,
3898 output->ctrl_url, output->data_url, session->consumer, new_output,
3899 &session->snapshot);
3900 if (ret < 0) {
3901 if (ret == -ENOMEM) {
3902 ret = LTTNG_ERR_NOMEM;
3903 } else {
3904 ret = LTTNG_ERR_INVALID;
3905 }
3906 goto free_error;
3907 }
3908
3909 rcu_read_lock();
3910 snapshot_add_output(&session->snapshot, new_output);
3911 if (id) {
3912 *id = new_output->id;
3913 }
3914 rcu_read_unlock();
3915
3916 return LTTNG_OK;
3917
3918 free_error:
3919 snapshot_output_destroy(new_output);
3920 error:
3921 return ret;
3922 }
3923
3924 /*
3925 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3926 *
3927 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3928 */
3929 int cmd_snapshot_del_output(struct ltt_session *session,
3930 const struct lttng_snapshot_output *output)
3931 {
3932 int ret;
3933 struct snapshot_output *sout = NULL;
3934
3935 assert(session);
3936 assert(output);
3937
3938 rcu_read_lock();
3939
3940 /*
3941 * Permission denied to create an output if the session is not
3942 * set in no output mode.
3943 */
3944 if (session->output_traces) {
3945 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3946 goto error;
3947 }
3948
3949 if (output->id) {
3950 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3951 session->name);
3952 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3953 } else if (*output->name != '\0') {
3954 DBG("Cmd snapshot del output name %s for session %s", output->name,
3955 session->name);
3956 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3957 }
3958 if (!sout) {
3959 ret = LTTNG_ERR_INVALID;
3960 goto error;
3961 }
3962
3963 snapshot_delete_output(&session->snapshot, sout);
3964 snapshot_output_destroy(sout);
3965 ret = LTTNG_OK;
3966
3967 error:
3968 rcu_read_unlock();
3969 return ret;
3970 }
3971
3972 /*
3973 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3974 *
3975 * If no output is available, outputs is untouched and 0 is returned.
3976 *
3977 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3978 */
3979 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3980 struct lttng_snapshot_output **outputs)
3981 {
3982 int ret, idx = 0;
3983 struct lttng_snapshot_output *list = NULL;
3984 struct lttng_ht_iter iter;
3985 struct snapshot_output *output;
3986
3987 assert(session);
3988 assert(outputs);
3989
3990 DBG("Cmd snapshot list outputs for session %s", session->name);
3991
3992 /*
3993 * Permission denied to create an output if the session is not
3994 * set in no output mode.
3995 */
3996 if (session->output_traces) {
3997 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3998 goto end;
3999 }
4000
4001 if (session->snapshot.nb_output == 0) {
4002 ret = 0;
4003 goto end;
4004 }
4005
4006 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
4007 if (!list) {
4008 ret = -LTTNG_ERR_NOMEM;
4009 goto end;
4010 }
4011
4012 /* Copy list from session to the new list object. */
4013 rcu_read_lock();
4014 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
4015 output, node.node) {
4016 assert(output->consumer);
4017 list[idx].id = output->id;
4018 list[idx].max_size = output->max_size;
4019 if (lttng_strncpy(list[idx].name, output->name,
4020 sizeof(list[idx].name))) {
4021 ret = -LTTNG_ERR_INVALID;
4022 goto error;
4023 }
4024 if (output->consumer->type == CONSUMER_DST_LOCAL) {
4025 if (lttng_strncpy(list[idx].ctrl_url,
4026 output->consumer->dst.session_root_path,
4027 sizeof(list[idx].ctrl_url))) {
4028 ret = -LTTNG_ERR_INVALID;
4029 goto error;
4030 }
4031 } else {
4032 /* Control URI. */
4033 ret = uri_to_str_url(&output->consumer->dst.net.control,
4034 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
4035 if (ret < 0) {
4036 ret = -LTTNG_ERR_NOMEM;
4037 goto error;
4038 }
4039
4040 /* Data URI. */
4041 ret = uri_to_str_url(&output->consumer->dst.net.data,
4042 list[idx].data_url, sizeof(list[idx].data_url));
4043 if (ret < 0) {
4044 ret = -LTTNG_ERR_NOMEM;
4045 goto error;
4046 }
4047 }
4048 idx++;
4049 }
4050
4051 *outputs = list;
4052 list = NULL;
4053 ret = session->snapshot.nb_output;
4054 error:
4055 rcu_read_unlock();
4056 free(list);
4057 end:
4058 return ret;
4059 }
4060
4061 /*
4062 * Check if we can regenerate the metadata for this session.
4063 * Only kernel, UST per-uid and non-live sessions are supported.
4064 *
4065 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
4066 */
4067 static
4068 int check_regenerate_metadata_support(struct ltt_session *session)
4069 {
4070 int ret;
4071
4072 assert(session);
4073
4074 if (session->live_timer != 0) {
4075 ret = LTTNG_ERR_LIVE_SESSION;
4076 goto end;
4077 }
4078 if (!session->active) {
4079 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4080 goto end;
4081 }
4082 if (session->ust_session) {
4083 switch (session->ust_session->buffer_type) {
4084 case LTTNG_BUFFER_PER_UID:
4085 break;
4086 case LTTNG_BUFFER_PER_PID:
4087 ret = LTTNG_ERR_PER_PID_SESSION;
4088 goto end;
4089 default:
4090 assert(0);
4091 ret = LTTNG_ERR_UNK;
4092 goto end;
4093 }
4094 }
4095 if (session->consumer->type == CONSUMER_DST_NET &&
4096 session->consumer->relay_minor_version < 8) {
4097 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
4098 goto end;
4099 }
4100 ret = 0;
4101
4102 end:
4103 return ret;
4104 }
4105
4106 static
4107 int clear_metadata_file(int fd)
4108 {
4109 int ret;
4110 off_t lseek_ret;
4111
4112 lseek_ret = lseek(fd, 0, SEEK_SET);
4113 if (lseek_ret < 0) {
4114 PERROR("lseek");
4115 ret = -1;
4116 goto end;
4117 }
4118
4119 ret = ftruncate(fd, 0);
4120 if (ret < 0) {
4121 PERROR("ftruncate");
4122 goto end;
4123 }
4124
4125 end:
4126 return ret;
4127 }
4128
4129 static
4130 int ust_regenerate_metadata(struct ltt_ust_session *usess)
4131 {
4132 int ret = 0;
4133 struct buffer_reg_uid *uid_reg = NULL;
4134 struct buffer_reg_session *session_reg = NULL;
4135
4136 rcu_read_lock();
4137 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
4138 struct ust_registry_session *registry;
4139 struct ust_registry_channel *chan;
4140 struct lttng_ht_iter iter_chan;
4141
4142 session_reg = uid_reg->registry;
4143 registry = session_reg->reg.ust;
4144
4145 pthread_mutex_lock(&registry->lock);
4146 registry->metadata_len_sent = 0;
4147 memset(registry->metadata, 0, registry->metadata_alloc_len);
4148 registry->metadata_len = 0;
4149 registry->metadata_version++;
4150 if (registry->metadata_fd > 0) {
4151 /* Clear the metadata file's content. */
4152 ret = clear_metadata_file(registry->metadata_fd);
4153 if (ret) {
4154 pthread_mutex_unlock(&registry->lock);
4155 goto end;
4156 }
4157 }
4158
4159 ret = ust_metadata_session_statedump(registry, NULL,
4160 registry->major, registry->minor);
4161 if (ret) {
4162 pthread_mutex_unlock(&registry->lock);
4163 ERR("Failed to generate session metadata (err = %d)",
4164 ret);
4165 goto end;
4166 }
4167 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
4168 chan, node.node) {
4169 struct ust_registry_event *event;
4170 struct lttng_ht_iter iter_event;
4171
4172 ret = ust_metadata_channel_statedump(registry, chan);
4173 if (ret) {
4174 pthread_mutex_unlock(&registry->lock);
4175 ERR("Failed to generate channel metadata "
4176 "(err = %d)", ret);
4177 goto end;
4178 }
4179 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
4180 event, node.node) {
4181 ret = ust_metadata_event_statedump(registry,
4182 chan, event);
4183 if (ret) {
4184 pthread_mutex_unlock(&registry->lock);
4185 ERR("Failed to generate event metadata "
4186 "(err = %d)", ret);
4187 goto end;
4188 }
4189 }
4190 }
4191 pthread_mutex_unlock(&registry->lock);
4192 }
4193
4194 end:
4195 rcu_read_unlock();
4196 return ret;
4197 }
4198
4199 /*
4200 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4201 *
4202 * Ask the consumer to truncate the existing metadata file(s) and
4203 * then regenerate the metadata. Live and per-pid sessions are not
4204 * supported and return an error.
4205 *
4206 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4207 */
4208 int cmd_regenerate_metadata(struct ltt_session *session)
4209 {
4210 int ret;
4211
4212 assert(session);
4213
4214 ret = check_regenerate_metadata_support(session);
4215 if (ret) {
4216 goto end;
4217 }
4218
4219 if (session->kernel_session) {
4220 ret = kernctl_session_regenerate_metadata(
4221 session->kernel_session->fd);
4222 if (ret < 0) {
4223 ERR("Failed to regenerate the kernel metadata");
4224 goto end;
4225 }
4226 }
4227
4228 if (session->ust_session) {
4229 ret = ust_regenerate_metadata(session->ust_session);
4230 if (ret < 0) {
4231 ERR("Failed to regenerate the UST metadata");
4232 goto end;
4233 }
4234 }
4235 DBG("Cmd metadata regenerate for session %s", session->name);
4236 ret = LTTNG_OK;
4237
4238 end:
4239 return ret;
4240 }
4241
4242 /*
4243 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4244 *
4245 * Ask the tracer to regenerate a new statedump.
4246 *
4247 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4248 */
4249 int cmd_regenerate_statedump(struct ltt_session *session)
4250 {
4251 int ret;
4252
4253 assert(session);
4254
4255 if (!session->active) {
4256 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4257 goto end;
4258 }
4259
4260 if (session->kernel_session) {
4261 ret = kernctl_session_regenerate_statedump(
4262 session->kernel_session->fd);
4263 /*
4264 * Currently, the statedump in kernel can only fail if out
4265 * of memory.
4266 */
4267 if (ret < 0) {
4268 if (ret == -ENOMEM) {
4269 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4270 } else {
4271 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4272 }
4273 ERR("Failed to regenerate the kernel statedump");
4274 goto end;
4275 }
4276 }
4277
4278 if (session->ust_session) {
4279 ret = ust_app_regenerate_statedump_all(session->ust_session);
4280 /*
4281 * Currently, the statedump in UST always returns 0.
4282 */
4283 if (ret < 0) {
4284 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4285 ERR("Failed to regenerate the UST statedump");
4286 goto end;
4287 }
4288 }
4289 DBG("Cmd regenerate statedump for session %s", session->name);
4290 ret = LTTNG_OK;
4291
4292 end:
4293 return ret;
4294 }
4295
4296 static enum lttng_error_code trigger_modifies_event_notifier(
4297 const struct lttng_trigger *trigger, bool *adds_event_notifier)
4298 {
4299 enum lttng_error_code ret_code = LTTNG_OK;
4300 const struct lttng_condition *condition = NULL;
4301
4302 condition = lttng_trigger_get_const_condition(trigger);
4303 if (!condition) {
4304 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4305 goto end;
4306 }
4307
4308 *adds_event_notifier = lttng_condition_get_type(condition) ==
4309 LTTNG_CONDITION_TYPE_EVENT_RULE_HIT;
4310 end:
4311 return ret_code;
4312 }
4313
4314 enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_creds,
4315 struct lttng_trigger *trigger,
4316 struct notification_thread_handle *notification_thread,
4317 struct lttng_trigger **return_trigger)
4318 {
4319 enum lttng_error_code ret_code;
4320 bool must_update_event_notifiers;
4321 const char *trigger_name;
4322 uid_t trigger_owner;
4323 enum lttng_trigger_status trigger_status;
4324
4325 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4326 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4327 trigger_name : "(unnamed)";
4328
4329 trigger_status = lttng_trigger_get_owner_uid(
4330 trigger, &trigger_owner);
4331 assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4332
4333 DBG("Running register trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4334 trigger_name, (int) trigger_owner,
4335 (int) lttng_credentials_get_uid(cmd_creds));
4336
4337 /*
4338 * Validate the trigger credentials against the command credentials.
4339 * Only the root user can register a trigger with non-matching
4340 * credentials.
4341 */
4342 if (!lttng_credentials_is_equal_uid(
4343 lttng_trigger_get_credentials(trigger),
4344 cmd_creds)) {
4345 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4346 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4347 trigger_name, (int) trigger_owner,
4348 (int) lttng_credentials_get_uid(cmd_creds));
4349 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4350 goto end;
4351 }
4352 }
4353
4354 /*
4355 * The bytecode generation also serves as a validation step for the
4356 * bytecode expressions.
4357 */
4358 ret_code = lttng_trigger_generate_bytecode(trigger, cmd_creds);
4359 if (ret_code != LTTNG_OK) {
4360 ERR("Failed to generate bytecode of trigger: trigger name = '%s', trigger owner uid = %d, error code = %d",
4361 trigger_name, (int) trigger_owner, ret_code);
4362 goto end;
4363 }
4364
4365 /*
4366 * A reference to the trigger is acquired by the notification thread.
4367 * It is safe to return the same trigger to the caller since it the
4368 * other user holds a reference.
4369 *
4370 * The trigger is modified during the execution of the
4371 * "register trigger" command. However, by the time the command returns,
4372 * it is safe to use without any locking as its properties are
4373 * immutable.
4374 */
4375 ret_code = notification_thread_command_register_trigger(notification_thread,
4376 trigger);
4377 if (ret_code != LTTNG_OK) {
4378 DBG("Failed to register trigger to notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4379 trigger_name, (int) trigger_owner, ret_code);
4380 goto end;
4381 }
4382
4383 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4384 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4385 trigger_name : "(unnamed)";
4386
4387 ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifiers);
4388 if (ret_code != LTTNG_OK) {
4389 ERR("Failed to determine if event modifies event notifiers: trigger name = '%s', trigger owner uid = %d, error code = %d",
4390 trigger_name, (int) trigger_owner, ret_code);
4391 goto end;
4392 }
4393
4394 /*
4395 * Synchronize tracers if the trigger adds an event notifier.
4396 */
4397 if (must_update_event_notifiers) {
4398 const enum lttng_domain_type trigger_domain =
4399 lttng_trigger_get_underlying_domain_type_restriction(trigger);
4400
4401 session_lock_list();
4402 switch (trigger_domain) {
4403 case LTTNG_DOMAIN_KERNEL:
4404 {
4405 ret_code = kernel_register_event_notifier(
4406 trigger, cmd_creds);
4407 if (ret_code != LTTNG_OK) {
4408 const enum lttng_error_code notif_thread_unregister_ret =
4409 notification_thread_command_unregister_trigger(
4410 notification_thread,
4411 trigger);
4412
4413 if (notif_thread_unregister_ret != LTTNG_OK) {
4414 /* Return the original error code. */
4415 ERR("Failed to unregister trigger from notification thread during error recovery: trigger name = '%s', trigger owner uid = %d, error code = %d",
4416 trigger_name,
4417 (int) trigger_owner,
4418 ret_code);
4419 }
4420 }
4421 break;
4422 }
4423 case LTTNG_DOMAIN_UST:
4424 ust_app_global_update_all_event_notifier_rules();
4425 break;
4426 case LTTNG_DOMAIN_NONE:
4427 abort();
4428 default:
4429 {
4430 /* Agent domains. */
4431 struct agent *agt = agent_find_by_event_notifier_domain(
4432 trigger_domain);
4433
4434 if (!agt) {
4435 agt = agent_create(trigger_domain);
4436 if (!agt) {
4437 ret_code = LTTNG_ERR_NOMEM;
4438 goto end_unlock_session_list;
4439 }
4440 agent_add(agt, trigger_agents_ht_by_domain);
4441 }
4442
4443 ret_code = trigger_agent_enable(trigger, agt);
4444 if (ret_code != LTTNG_OK) {
4445 goto end_unlock_session_list;
4446 }
4447
4448 break;
4449 }
4450 }
4451
4452 session_unlock_list();
4453 }
4454
4455 /*
4456 * Return an updated trigger to the client.
4457 *
4458 * Since a modified version of the same trigger is returned, acquire a
4459 * reference to the trigger so the caller doesn't have to care if those
4460 * are distinct instances or not.
4461 */
4462 if (ret_code == LTTNG_OK) {
4463 lttng_trigger_get(trigger);
4464 *return_trigger = trigger;
4465 /* Ownership of trigger was transferred to caller. */
4466 trigger = NULL;
4467 }
4468 end:
4469 return ret_code;
4470 end_unlock_session_list:
4471 session_unlock_list();
4472 return ret_code;
4473 }
4474
4475 enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd_creds,
4476 const struct lttng_trigger *trigger,
4477 struct notification_thread_handle *notification_thread)
4478 {
4479 enum lttng_error_code ret_code;
4480 bool must_update_event_notifiers;
4481 const char *trigger_name;
4482 uid_t trigger_owner;
4483 enum lttng_trigger_status trigger_status;
4484
4485 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4486 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(unnamed)";
4487 trigger_status = lttng_trigger_get_owner_uid(
4488 trigger, &trigger_owner);
4489 assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4490
4491 DBG("Running unregister trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4492 trigger_name, (int) trigger_owner,
4493 (int) lttng_credentials_get_uid(cmd_creds));
4494
4495 /*
4496 * Validate the trigger credentials against the command credentials.
4497 * Only the root user can unregister a trigger with non-matching
4498 * credentials.
4499 */
4500 if (!lttng_credentials_is_equal_uid(
4501 lttng_trigger_get_credentials(trigger),
4502 cmd_creds)) {
4503 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4504 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4505 trigger_name, (int) trigger_owner,
4506 (int) lttng_credentials_get_uid(cmd_creds));
4507 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4508 goto end;
4509 }
4510 }
4511
4512 ret_code = trigger_modifies_event_notifier(trigger, &must_update_event_notifiers);
4513 if (ret_code != LTTNG_OK) {
4514 ERR("Failed to determine if event modifies event notifiers: trigger name = '%s', trigger owner uid = %d, error code = %d",
4515 trigger_name, (int) trigger_owner, ret_code);
4516 goto end;
4517 }
4518
4519 ret_code = notification_thread_command_unregister_trigger(notification_thread,
4520 trigger);
4521 if (ret_code != LTTNG_OK) {
4522 DBG("Failed to unregister trigger from notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4523 trigger_name, (int) trigger_owner, ret_code);
4524 }
4525
4526 /*
4527 * Synchronize tracers if the trigger removes an event notifier.
4528 * Do this even if the trigger unregistration failed to at least stop
4529 * the tracers from producing notifications associated with this
4530 * event notifier.
4531 */
4532 if (must_update_event_notifiers) {
4533 const enum lttng_domain_type trigger_domain =
4534 lttng_trigger_get_underlying_domain_type_restriction(
4535 trigger);
4536
4537 session_lock_list();
4538 switch (trigger_domain) {
4539 case LTTNG_DOMAIN_KERNEL:
4540 {
4541 ret_code = kernel_unregister_event_notifier(
4542 trigger);
4543 break;
4544 }
4545 case LTTNG_DOMAIN_UST:
4546 ust_app_global_update_all_event_notifier_rules();
4547 break;
4548 case LTTNG_DOMAIN_NONE:
4549 abort();
4550 default:
4551 {
4552 /* Agent domains. */
4553 struct agent *agt = agent_find_by_event_notifier_domain(
4554 trigger_domain);
4555
4556 if (!agt) {
4557 agt = agent_create(trigger_domain);
4558 if (!agt) {
4559 ret_code = LTTNG_ERR_NOMEM;
4560 goto end_unlock_session_list;
4561 }
4562 agent_add(agt, trigger_agents_ht_by_domain);
4563 }
4564
4565 ret_code = trigger_agent_disable(trigger, agt);
4566 if (ret_code != LTTNG_OK) {
4567 goto end_unlock_session_list;
4568 }
4569
4570 break;
4571 }
4572 }
4573
4574 session_unlock_list();
4575 }
4576
4577 end:
4578 return ret_code;
4579 end_unlock_session_list:
4580 session_unlock_list();
4581 return ret_code;}
4582
4583 int cmd_list_triggers(struct command_ctx *cmd_ctx,
4584 struct notification_thread_handle *notification_thread,
4585 struct lttng_triggers **return_triggers)
4586 {
4587 int ret = 0;
4588 enum lttng_error_code ret_code;
4589 struct lttng_triggers *triggers = NULL;
4590
4591 /* Get the set of triggers from the notification thread. */
4592 ret_code = notification_thread_command_list_triggers(
4593 notification_thread, cmd_ctx->creds.uid, &triggers);
4594 if (ret_code != LTTNG_OK) {
4595 ret = ret_code;
4596 goto end;
4597 }
4598
4599 *return_triggers = triggers;
4600 triggers = NULL;
4601 ret = LTTNG_OK;
4602 end:
4603 lttng_triggers_destroy(triggers);
4604 return ret;
4605 }
4606 /*
4607 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4608 * snapshot output is *not* set with a remote destination.
4609 *
4610 * Return LTTNG_OK on success or a LTTNG_ERR code.
4611 */
4612 static enum lttng_error_code set_relayd_for_snapshot(
4613 struct consumer_output *output,
4614 const struct ltt_session *session)
4615 {
4616 enum lttng_error_code status = LTTNG_OK;
4617 struct lttng_ht_iter iter;
4618 struct consumer_socket *socket;
4619 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4620 const char *base_path;
4621
4622 assert(output);
4623 assert(session);
4624
4625 DBG2("Set relayd object from snapshot output");
4626
4627 if (session->current_trace_chunk) {
4628 enum lttng_trace_chunk_status chunk_status =
4629 lttng_trace_chunk_get_id(
4630 session->current_trace_chunk,
4631 &current_chunk_id.value);
4632
4633 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
4634 current_chunk_id.is_set = true;
4635 } else {
4636 ERR("Failed to get current trace chunk id");
4637 status = LTTNG_ERR_UNK;
4638 goto error;
4639 }
4640 }
4641
4642 /* Ignore if snapshot consumer output is not network. */
4643 if (output->type != CONSUMER_DST_NET) {
4644 goto error;
4645 }
4646
4647 /*
4648 * The snapshot record URI base path overrides the session
4649 * base path.
4650 */
4651 if (output->dst.net.control.subdir[0] != '\0') {
4652 base_path = output->dst.net.control.subdir;
4653 } else {
4654 base_path = session->base_path;
4655 }
4656
4657 /*
4658 * For each consumer socket, create and send the relayd object of the
4659 * snapshot output.
4660 */
4661 rcu_read_lock();
4662 cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
4663 socket, node.node) {
4664 pthread_mutex_lock(socket->lock);
4665 status = send_consumer_relayd_sockets(0, session->id,
4666 output, socket,
4667 session->name, session->hostname,
4668 base_path,
4669 session->live_timer,
4670 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
4671 session->creation_time,
4672 session->name_contains_creation_time);
4673 pthread_mutex_unlock(socket->lock);
4674 if (status != LTTNG_OK) {
4675 rcu_read_unlock();
4676 goto error;
4677 }
4678 }
4679 rcu_read_unlock();
4680
4681 error:
4682 return status;
4683 }
4684
4685 /*
4686 * Record a kernel snapshot.
4687 *
4688 * Return LTTNG_OK on success or a LTTNG_ERR code.
4689 */
4690 static enum lttng_error_code record_kernel_snapshot(
4691 struct ltt_kernel_session *ksess,
4692 const struct consumer_output *output,
4693 const struct ltt_session *session,
4694 int wait, uint64_t nb_packets_per_stream)
4695 {
4696 enum lttng_error_code status;
4697
4698 assert(ksess);
4699 assert(output);
4700 assert(session);
4701
4702 status = kernel_snapshot_record(
4703 ksess, output, wait, nb_packets_per_stream);
4704 return status;
4705 }
4706
4707 /*
4708 * Record a UST snapshot.
4709 *
4710 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
4711 */
4712 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
4713 const struct consumer_output *output,
4714 const struct ltt_session *session,
4715 int wait, uint64_t nb_packets_per_stream)
4716 {
4717 enum lttng_error_code status;
4718
4719 assert(usess);
4720 assert(output);
4721 assert(session);
4722
4723 status = ust_app_snapshot_record(
4724 usess, output, wait, nb_packets_per_stream);
4725 return status;
4726 }
4727
4728 static
4729 uint64_t get_session_size_one_more_packet_per_stream(
4730 const struct ltt_session *session, uint64_t cur_nr_packets)
4731 {
4732 uint64_t tot_size = 0;
4733
4734 if (session->kernel_session) {
4735 struct ltt_kernel_channel *chan;
4736 const struct ltt_kernel_session *ksess =
4737 session->kernel_session;
4738
4739 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
4740 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
4741 /*
4742 * Don't take channel into account if we
4743 * already grab all its packets.
4744 */
4745 continue;
4746 }
4747 tot_size += chan->channel->attr.subbuf_size
4748 * chan->stream_count;
4749 }
4750 }
4751
4752 if (session->ust_session) {
4753 const struct ltt_ust_session *usess = session->ust_session;
4754
4755 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
4756 cur_nr_packets);
4757 }
4758
4759 return tot_size;
4760 }
4761
4762 /*
4763 * Calculate the number of packets we can grab from each stream that
4764 * fits within the overall snapshot max size.
4765 *
4766 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
4767 * the number of packets per stream.
4768 *
4769 * TODO: this approach is not perfect: we consider the worse case
4770 * (packet filling the sub-buffers) as an upper bound, but we could do
4771 * better if we do this calculation while we actually grab the packet
4772 * content: we would know how much padding we don't actually store into
4773 * the file.
4774 *
4775 * This algorithm is currently bounded by the number of packets per
4776 * stream.
4777 *
4778 * Since we call this algorithm before actually grabbing the data, it's
4779 * an approximation: for instance, applications could appear/disappear
4780 * in between this call and actually grabbing data.
4781 */
4782 static
4783 int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
4784 uint64_t max_size)
4785 {
4786 int64_t size_left;
4787 uint64_t cur_nb_packets = 0;
4788
4789 if (!max_size) {
4790 return 0; /* Infinite */
4791 }
4792
4793 size_left = max_size;
4794 for (;;) {
4795 uint64_t one_more_packet_tot_size;
4796
4797 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(
4798 session, cur_nb_packets);
4799 if (!one_more_packet_tot_size) {
4800 /* We are already grabbing all packets. */
4801 break;
4802 }
4803 size_left -= one_more_packet_tot_size;
4804 if (size_left < 0) {
4805 break;
4806 }
4807 cur_nb_packets++;
4808 }
4809 if (!cur_nb_packets && size_left != max_size) {
4810 /* Not enough room to grab one packet of each stream, error. */
4811 return -1;
4812 }
4813 return cur_nb_packets;
4814 }
4815
4816 static
4817 enum lttng_error_code snapshot_record(struct ltt_session *session,
4818 const struct snapshot_output *snapshot_output, int wait)
4819 {
4820 int64_t nb_packets_per_stream;
4821 char snapshot_chunk_name[LTTNG_NAME_MAX];
4822 int ret;
4823 enum lttng_error_code ret_code = LTTNG_OK;
4824 struct lttng_trace_chunk *snapshot_trace_chunk;
4825 struct consumer_output *original_ust_consumer_output = NULL;
4826 struct consumer_output *original_kernel_consumer_output = NULL;
4827 struct consumer_output *snapshot_ust_consumer_output = NULL;
4828 struct consumer_output *snapshot_kernel_consumer_output = NULL;
4829
4830 ret = snprintf(snapshot_chunk_name, sizeof(snapshot_chunk_name),
4831 "%s-%s-%" PRIu64,
4832 snapshot_output->name,
4833 snapshot_output->datetime,
4834 snapshot_output->nb_snapshot);
4835 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
4836 ERR("Failed to format snapshot name");
4837 ret_code = LTTNG_ERR_INVALID;
4838 goto error;
4839 }
4840 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
4841 snapshot_output->name, session->name,
4842 snapshot_chunk_name);
4843 if (!session->kernel_session && !session->ust_session) {
4844 ERR("Failed to record snapshot as no channels exist");
4845 ret_code = LTTNG_ERR_NO_CHANNEL;
4846 goto error;
4847 }
4848
4849 if (session->kernel_session) {
4850 original_kernel_consumer_output =
4851 session->kernel_session->consumer;
4852 snapshot_kernel_consumer_output =
4853 consumer_copy_output(snapshot_output->consumer);
4854 strcpy(snapshot_kernel_consumer_output->chunk_path,
4855 snapshot_chunk_name);
4856 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
4857 original_kernel_consumer_output);
4858 if (ret < 0) {
4859 ERR("Failed to copy consumer sockets from snapshot output configuration");
4860 ret_code = LTTNG_ERR_NOMEM;
4861 goto error;
4862 }
4863 ret_code = set_relayd_for_snapshot(
4864 snapshot_kernel_consumer_output, session);
4865 if (ret_code != LTTNG_OK) {
4866 ERR("Failed to setup relay daemon for kernel tracer snapshot");
4867 goto error;
4868 }
4869 session->kernel_session->consumer =
4870 snapshot_kernel_consumer_output;
4871 }
4872 if (session->ust_session) {
4873 original_ust_consumer_output = session->ust_session->consumer;
4874 snapshot_ust_consumer_output =
4875 consumer_copy_output(snapshot_output->consumer);
4876 strcpy(snapshot_ust_consumer_output->chunk_path,
4877 snapshot_chunk_name);
4878 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
4879 original_ust_consumer_output);
4880 if (ret < 0) {
4881 ERR("Failed to copy consumer sockets from snapshot output configuration");
4882 ret_code = LTTNG_ERR_NOMEM;
4883 goto error;
4884 }
4885 ret_code = set_relayd_for_snapshot(
4886 snapshot_ust_consumer_output, session);
4887 if (ret_code != LTTNG_OK) {
4888 ERR("Failed to setup relay daemon for userspace tracer snapshot");
4889 goto error;
4890 }
4891 session->ust_session->consumer =
4892 snapshot_ust_consumer_output;
4893 }
4894
4895 snapshot_trace_chunk = session_create_new_trace_chunk(session,
4896 snapshot_kernel_consumer_output ?:
4897 snapshot_ust_consumer_output,
4898 consumer_output_get_base_path(
4899 snapshot_output->consumer),
4900 snapshot_chunk_name);
4901 if (!snapshot_trace_chunk) {
4902 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
4903 session->name);
4904 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
4905 goto error;
4906 }
4907 assert(!session->current_trace_chunk);
4908 ret = session_set_trace_chunk(session, snapshot_trace_chunk, NULL);
4909 lttng_trace_chunk_put(snapshot_trace_chunk);
4910 snapshot_trace_chunk = NULL;
4911 if (ret) {
4912 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
4913 session->name);
4914 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4915 goto error;
4916 }
4917
4918 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4919 snapshot_output->max_size);
4920 if (nb_packets_per_stream < 0) {
4921 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
4922 goto error_close_trace_chunk;
4923 }
4924
4925 if (session->kernel_session) {
4926 ret_code = record_kernel_snapshot(session->kernel_session,
4927 snapshot_kernel_consumer_output, session,
4928 wait, nb_packets_per_stream);
4929 if (ret_code != LTTNG_OK) {
4930 goto error_close_trace_chunk;
4931 }
4932 }
4933
4934 if (session->ust_session) {
4935 ret_code = record_ust_snapshot(session->ust_session,
4936 snapshot_ust_consumer_output, session,
4937 wait, nb_packets_per_stream);
4938 if (ret_code != LTTNG_OK) {
4939 goto error_close_trace_chunk;
4940 }
4941 }
4942
4943 error_close_trace_chunk:
4944 if (session_set_trace_chunk(session, NULL, &snapshot_trace_chunk)) {
4945 ERR("Failed to release the current trace chunk of session \"%s\"",
4946 session->name);
4947 ret_code = LTTNG_ERR_UNK;
4948 }
4949
4950 if (session_close_trace_chunk(session, snapshot_trace_chunk,
4951 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION, NULL)) {
4952 /*
4953 * Don't goto end; make sure the chunk is closed for the session
4954 * to allow future snapshots.
4955 */
4956 ERR("Failed to close snapshot trace chunk of session \"%s\"",
4957 session->name);
4958 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
4959 }
4960 error:
4961 if (original_ust_consumer_output) {
4962 session->ust_session->consumer = original_ust_consumer_output;
4963 }
4964 if (original_kernel_consumer_output) {
4965 session->kernel_session->consumer =
4966 original_kernel_consumer_output;
4967 }
4968 consumer_output_put(snapshot_ust_consumer_output);
4969 consumer_output_put(snapshot_kernel_consumer_output);
4970 return ret_code;
4971 }
4972
4973 /*
4974 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
4975 *
4976 * The wait parameter is ignored so this call always wait for the snapshot to
4977 * complete before returning.
4978 *
4979 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4980 */
4981 int cmd_snapshot_record(struct ltt_session *session,
4982 const struct lttng_snapshot_output *output, int wait)
4983 {
4984 enum lttng_error_code cmd_ret = LTTNG_OK;
4985 int ret;
4986 unsigned int snapshot_success = 0;
4987 char datetime[16];
4988 struct snapshot_output *tmp_output = NULL;
4989
4990 assert(session);
4991 assert(output);
4992
4993 DBG("Cmd snapshot record for session %s", session->name);
4994
4995 /* Get the datetime for the snapshot output directory. */
4996 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
4997 sizeof(datetime));
4998 if (!ret) {
4999 cmd_ret = LTTNG_ERR_INVALID;
5000 goto error;
5001 }
5002
5003 /*
5004 * Permission denied to create an output if the session is not
5005 * set in no output mode.
5006 */
5007 if (session->output_traces) {
5008 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
5009 goto error;
5010 }
5011
5012 /* The session needs to be started at least once. */
5013 if (!session->has_been_started) {
5014 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5015 goto error;
5016 }
5017
5018 /* Use temporary output for the session. */
5019 if (*output->ctrl_url != '\0') {
5020 tmp_output = snapshot_output_alloc();
5021 if (!tmp_output) {
5022 cmd_ret = LTTNG_ERR_NOMEM;
5023 goto error;
5024 }
5025
5026 ret = snapshot_output_init(session, output->max_size,
5027 output->name,
5028 output->ctrl_url, output->data_url,
5029 session->consumer,
5030 tmp_output, NULL);
5031 if (ret < 0) {
5032 if (ret == -ENOMEM) {
5033 cmd_ret = LTTNG_ERR_NOMEM;
5034 } else {
5035 cmd_ret = LTTNG_ERR_INVALID;
5036 }
5037 goto error;
5038 }
5039 /* Use the global session count for the temporary snapshot. */
5040 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
5041
5042 /* Use the global datetime */
5043 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
5044 cmd_ret = snapshot_record(session, tmp_output, wait);
5045 if (cmd_ret != LTTNG_OK) {
5046 goto error;
5047 }
5048 snapshot_success = 1;
5049 } else {
5050 struct snapshot_output *sout;
5051 struct lttng_ht_iter iter;
5052
5053 rcu_read_lock();
5054 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
5055 &iter.iter, sout, node.node) {
5056 struct snapshot_output output_copy;
5057
5058 /*
5059 * Make a local copy of the output and override output
5060 * parameters with those provided as part of the
5061 * command.
5062 */
5063 memcpy(&output_copy, sout, sizeof(output_copy));
5064
5065 if (output->max_size != (uint64_t) -1ULL) {
5066 output_copy.max_size = output->max_size;
5067 }
5068
5069 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
5070 memcpy(output_copy.datetime, datetime,
5071 sizeof(datetime));
5072
5073 /* Use temporary name. */
5074 if (*output->name != '\0') {
5075 if (lttng_strncpy(output_copy.name,
5076 output->name,
5077 sizeof(output_copy.name))) {
5078 cmd_ret = LTTNG_ERR_INVALID;
5079 rcu_read_unlock();
5080 goto error;
5081 }
5082 }
5083
5084 cmd_ret = snapshot_record(session, &output_copy, wait);
5085 if (cmd_ret != LTTNG_OK) {
5086 rcu_read_unlock();
5087 goto error;
5088 }
5089 snapshot_success = 1;
5090 }
5091 rcu_read_unlock();
5092 }
5093
5094 if (snapshot_success) {
5095 session->snapshot.nb_snapshot++;
5096 } else {
5097 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
5098 }
5099
5100 error:
5101 if (tmp_output) {
5102 snapshot_output_destroy(tmp_output);
5103 }
5104 return cmd_ret;
5105 }
5106
5107 /*
5108 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
5109 */
5110 int cmd_set_session_shm_path(struct ltt_session *session,
5111 const char *shm_path)
5112 {
5113 /* Safety net */
5114 assert(session);
5115
5116 /*
5117 * Can only set shm path before session is started.
5118 */
5119 if (session->has_been_started) {
5120 return LTTNG_ERR_SESSION_STARTED;
5121 }
5122
5123 strncpy(session->shm_path, shm_path,
5124 sizeof(session->shm_path));
5125 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
5126
5127 return LTTNG_OK;
5128 }
5129
5130 /*
5131 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
5132 *
5133 * Ask the consumer to rotate the session output directory.
5134 * The session lock must be held.
5135 *
5136 * Returns LTTNG_OK on success or else a negative LTTng error code.
5137 */
5138 int cmd_rotate_session(struct ltt_session *session,
5139 struct lttng_rotate_session_return *rotate_return,
5140 bool quiet_rotation,
5141 enum lttng_trace_chunk_command_type command)
5142 {
5143 int ret;
5144 uint64_t ongoing_rotation_chunk_id;
5145 enum lttng_error_code cmd_ret = LTTNG_OK;
5146 struct lttng_trace_chunk *chunk_being_archived = NULL;
5147 struct lttng_trace_chunk *new_trace_chunk = NULL;
5148 enum lttng_trace_chunk_status chunk_status;
5149 bool failed_to_rotate = false;
5150 enum lttng_error_code rotation_fail_code = LTTNG_OK;
5151
5152 assert(session);
5153
5154 if (!session->has_been_started) {
5155 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5156 goto end;
5157 }
5158
5159 /*
5160 * Explicit rotation is not supported for live sessions.
5161 * However, live sessions can perform a quiet rotation on
5162 * destroy.
5163 * Rotation is not supported for snapshot traces (no output).
5164 */
5165 if ((!quiet_rotation && session->live_timer) ||
5166 !session->output_traces) {
5167 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5168 goto end;
5169 }
5170
5171 /* Unsupported feature in lttng-relayd before 2.11. */
5172 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
5173 (session->consumer->relay_major_version == 2 &&
5174 session->consumer->relay_minor_version < 11)) {
5175 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
5176 goto end;
5177 }
5178
5179 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
5180 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
5181 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
5182 goto end;
5183 }
5184
5185 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
5186 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
5187 session->name);
5188 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
5189 goto end;
5190 }
5191
5192 /*
5193 * After a stop, we only allow one rotation to occur, the other ones are
5194 * useless until a new start.
5195 */
5196 if (session->rotated_after_last_stop) {
5197 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
5198 session->name);
5199 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
5200 goto end;
5201 }
5202
5203 /*
5204 * After a stop followed by a clear, disallow following rotations a they would
5205 * generate empty chunks.
5206 */
5207 if (session->cleared_after_last_stop) {
5208 DBG("Session \"%s\" was already cleared after stop, refusing rotation",
5209 session->name);
5210 cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
5211 goto end;
5212 }
5213
5214 if (session->active) {
5215 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
5216 NULL, NULL);
5217 if (!new_trace_chunk) {
5218 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
5219 goto error;
5220 }
5221 }
5222
5223 /*
5224 * The current trace chunk becomes the chunk being archived.
5225 *
5226 * After this point, "chunk_being_archived" must absolutely
5227 * be closed on the consumer(s), otherwise it will never be
5228 * cleaned-up, which will result in a leak.
5229 */
5230 ret = session_set_trace_chunk(session, new_trace_chunk,
5231 &chunk_being_archived);
5232 if (ret) {
5233 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5234 goto error;
5235 }
5236
5237 if (session->kernel_session) {
5238 cmd_ret = kernel_rotate_session(session);
5239 if (cmd_ret != LTTNG_OK) {
5240 failed_to_rotate = true;
5241 rotation_fail_code = cmd_ret;
5242 }
5243 }
5244 if (session->ust_session) {
5245 cmd_ret = ust_app_rotate_session(session);
5246 if (cmd_ret != LTTNG_OK) {
5247 failed_to_rotate = true;
5248 rotation_fail_code = cmd_ret;
5249 }
5250 }
5251
5252 if (!session->active) {
5253 session->rotated_after_last_stop = true;
5254 }
5255
5256 if (!chunk_being_archived) {
5257 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
5258 session->name);
5259 if (failed_to_rotate) {
5260 cmd_ret = rotation_fail_code;
5261 goto error;
5262 }
5263 cmd_ret = LTTNG_OK;
5264 goto end;
5265 }
5266
5267 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5268 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
5269 &ongoing_rotation_chunk_id);
5270 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5271
5272 ret = session_close_trace_chunk(session, chunk_being_archived,
5273 command, session->last_chunk_path);
5274 if (ret) {
5275 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5276 goto error;
5277 }
5278
5279 if (failed_to_rotate) {
5280 cmd_ret = rotation_fail_code;
5281 goto error;
5282 }
5283
5284 session->quiet_rotation = quiet_rotation;
5285 ret = timer_session_rotation_pending_check_start(session,
5286 DEFAULT_ROTATE_PENDING_TIMER);
5287 if (ret) {
5288 cmd_ret = LTTNG_ERR_UNK;
5289 goto error;
5290 }
5291
5292 if (rotate_return) {
5293 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5294 }
5295
5296 session->chunk_being_archived = chunk_being_archived;
5297 chunk_being_archived = NULL;
5298 if (!quiet_rotation) {
5299 ret = notification_thread_command_session_rotation_ongoing(
5300 notification_thread_handle,
5301 session->name, session->uid, session->gid,
5302 ongoing_rotation_chunk_id);
5303 if (ret != LTTNG_OK) {
5304 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5305 session->name);
5306 cmd_ret = ret;
5307 }
5308 }
5309
5310 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5311 session->name, ongoing_rotation_chunk_id);
5312 end:
5313 lttng_trace_chunk_put(new_trace_chunk);
5314 lttng_trace_chunk_put(chunk_being_archived);
5315 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5316 return ret;
5317 error:
5318 if (session_reset_rotation_state(session,
5319 LTTNG_ROTATION_STATE_ERROR)) {
5320 ERR("Failed to reset rotation state of session \"%s\"",
5321 session->name);
5322 }
5323 goto end;
5324 }
5325
5326 /*
5327 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5328 *
5329 * Check if the session has finished its rotation.
5330 *
5331 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5332 */
5333 int cmd_rotate_get_info(struct ltt_session *session,
5334 struct lttng_rotation_get_info_return *info_return,
5335 uint64_t rotation_id)
5336 {
5337 enum lttng_error_code cmd_ret = LTTNG_OK;
5338 enum lttng_rotation_state rotation_state;
5339
5340 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
5341 session->most_recent_chunk_id.value);
5342
5343 if (session->chunk_being_archived) {
5344 enum lttng_trace_chunk_status chunk_status;
5345 uint64_t chunk_id;
5346
5347 chunk_status = lttng_trace_chunk_get_id(
5348 session->chunk_being_archived,
5349 &chunk_id);
5350 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5351
5352 rotation_state = rotation_id == chunk_id ?
5353 LTTNG_ROTATION_STATE_ONGOING :
5354 LTTNG_ROTATION_STATE_EXPIRED;
5355 } else {
5356 if (session->last_archived_chunk_id.is_set &&
5357 rotation_id != session->last_archived_chunk_id.value) {
5358 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5359 } else {
5360 rotation_state = session->rotation_state;
5361 }
5362 }
5363
5364 switch (rotation_state) {
5365 case LTTNG_ROTATION_STATE_NO_ROTATION:
5366 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5367 session->name);
5368 goto end;
5369 case LTTNG_ROTATION_STATE_EXPIRED:
5370 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
5371 rotation_id, session->name);
5372 break;
5373 case LTTNG_ROTATION_STATE_ONGOING:
5374 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5375 rotation_id, session->name);
5376 break;
5377 case LTTNG_ROTATION_STATE_COMPLETED:
5378 {
5379 int fmt_ret;
5380 char *chunk_path;
5381 char *current_tracing_path_reply;
5382 size_t current_tracing_path_reply_len;
5383
5384 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5385 rotation_id, session->name);
5386
5387 switch (session_get_consumer_destination_type(session)) {
5388 case CONSUMER_DST_LOCAL:
5389 current_tracing_path_reply =
5390 info_return->location.local.absolute_path;
5391 current_tracing_path_reply_len =
5392 sizeof(info_return->location.local.absolute_path);
5393 info_return->location_type =
5394 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5395 fmt_ret = asprintf(&chunk_path,
5396 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5397 session_get_base_path(session),
5398 session->last_archived_chunk_name);
5399 if (fmt_ret == -1) {
5400 PERROR("Failed to format the path of the last archived trace chunk");
5401 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5402 cmd_ret = LTTNG_ERR_UNK;
5403 goto end;
5404 }
5405 break;
5406 case CONSUMER_DST_NET:
5407 {
5408 uint16_t ctrl_port, data_port;
5409
5410 current_tracing_path_reply =
5411 info_return->location.relay.relative_path;
5412 current_tracing_path_reply_len =
5413 sizeof(info_return->location.relay.relative_path);
5414 /* Currently the only supported relay protocol. */
5415 info_return->location.relay.protocol =
5416 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5417
5418 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5419 session_get_net_consumer_hostname(session),
5420 sizeof(info_return->location.relay.host));
5421 if (fmt_ret) {
5422 ERR("Failed to copy host name to rotate_get_info reply");
5423 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5424 cmd_ret = LTTNG_ERR_SET_URL;
5425 goto end;
5426 }
5427
5428 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5429 info_return->location.relay.ports.control = ctrl_port;
5430 info_return->location.relay.ports.data = data_port;
5431 info_return->location_type =
5432 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5433 chunk_path = strdup(session->last_chunk_path);
5434 if (!chunk_path) {
5435 ERR("Failed to allocate the path of the last archived trace chunk");
5436 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5437 cmd_ret = LTTNG_ERR_UNK;
5438 goto end;
5439 }
5440 break;
5441 }
5442 default:
5443 abort();
5444 }
5445
5446 fmt_ret = lttng_strncpy(current_tracing_path_reply,
5447 chunk_path, current_tracing_path_reply_len);
5448 free(chunk_path);
5449 if (fmt_ret) {
5450 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5451 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5452 cmd_ret = LTTNG_ERR_UNK;
5453 goto end;
5454 }
5455
5456 break;
5457 }
5458 case LTTNG_ROTATION_STATE_ERROR:
5459 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
5460 rotation_id, session->name);
5461 break;
5462 default:
5463 abort();
5464 }
5465
5466 cmd_ret = LTTNG_OK;
5467 end:
5468 info_return->status = (int32_t) rotation_state;
5469 return cmd_ret;
5470 }
5471
5472 /*
5473 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5474 *
5475 * Configure the automatic rotation parameters.
5476 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5477 * 'activate' to false means deactivate the rotation schedule and validate that
5478 * 'new_value' has the same value as the currently active value.
5479 *
5480 * Return LTTNG_OK on success or else a positive LTTNG_ERR code.
5481 */
5482 int cmd_rotation_set_schedule(struct ltt_session *session,
5483 bool activate, enum lttng_rotation_schedule_type schedule_type,
5484 uint64_t new_value,
5485 struct notification_thread_handle *notification_thread_handle)
5486 {
5487 int ret;
5488 uint64_t *parameter_value;
5489
5490 assert(session);
5491
5492 DBG("Cmd rotate set schedule session %s", session->name);
5493
5494 if (session->live_timer || !session->output_traces) {
5495 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5496 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5497 goto end;
5498 }
5499
5500 switch (schedule_type) {
5501 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5502 parameter_value = &session->rotate_size;
5503 break;
5504 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5505 parameter_value = &session->rotate_timer_period;
5506 if (new_value >= UINT_MAX) {
5507 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5508 new_value, UINT_MAX);
5509 ret = LTTNG_ERR_INVALID;
5510 goto end;
5511 }
5512 break;
5513 default:
5514 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5515 ret = LTTNG_ERR_INVALID;
5516 goto end;
5517 }
5518
5519 /* Improper use of the API. */
5520 if (new_value == -1ULL) {
5521 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5522 ret = LTTNG_ERR_INVALID;
5523 goto end;
5524 }
5525
5526 /*
5527 * As indicated in struct ltt_session's comments, a value of == 0 means
5528 * this schedule rotation type is not in use.
5529 *
5530 * Reject the command if we were asked to activate a schedule that was
5531 * already active.
5532 */
5533 if (activate && *parameter_value != 0) {
5534 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5535 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5536 goto end;
5537 }
5538
5539 /*
5540 * Reject the command if we were asked to deactivate a schedule that was
5541 * not active.
5542 */
5543 if (!activate && *parameter_value == 0) {
5544 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5545 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5546 goto end;
5547 }
5548
5549 /*
5550 * Reject the command if we were asked to deactivate a schedule that
5551 * doesn't exist.
5552 */
5553 if (!activate && *parameter_value != new_value) {
5554 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5555 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5556 goto end;
5557 }
5558
5559 *parameter_value = activate ? new_value : 0;
5560
5561 switch (schedule_type) {
5562 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5563 if (activate && session->active) {
5564 /*
5565 * Only start the timer if the session is active,
5566 * otherwise it will be started when the session starts.
5567 */
5568 ret = timer_session_rotation_schedule_timer_start(
5569 session, new_value);
5570 if (ret) {
5571 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5572 ret = LTTNG_ERR_UNK;
5573 goto end;
5574 }
5575 } else {
5576 ret = timer_session_rotation_schedule_timer_stop(
5577 session);
5578 if (ret) {
5579 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5580 ret = LTTNG_ERR_UNK;
5581 goto end;
5582 }
5583 }
5584 break;
5585 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5586 if (activate) {
5587 ret = subscribe_session_consumed_size_rotation(session,
5588 new_value, notification_thread_handle);
5589 if (ret) {
5590 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5591 ret = LTTNG_ERR_UNK;
5592 goto end;
5593 }
5594 } else {
5595 ret = unsubscribe_session_consumed_size_rotation(session,
5596 notification_thread_handle);
5597 if (ret) {
5598 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5599 ret = LTTNG_ERR_UNK;
5600 goto end;
5601 }
5602
5603 }
5604 break;
5605 default:
5606 /* Would have been caught before. */
5607 abort();
5608 }
5609
5610 ret = LTTNG_OK;
5611
5612 goto end;
5613
5614 end:
5615 return ret;
5616 }
5617
5618 /* Wait for a given path to be removed before continuing. */
5619 static enum lttng_error_code wait_on_path(void *path_data)
5620 {
5621 const char *shm_path = path_data;
5622
5623 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
5624 shm_path);
5625 while (true) {
5626 int ret;
5627 struct stat st;
5628
5629 ret = stat(shm_path, &st);
5630 if (ret) {
5631 if (errno != ENOENT) {
5632 PERROR("stat() returned an error while checking for the existence of the shm path");
5633 } else {
5634 DBG("shm path no longer exists, completing the destruction of session");
5635 }
5636 break;
5637 } else {
5638 if (!S_ISDIR(st.st_mode)) {
5639 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5640 shm_path);
5641 break;
5642 }
5643 }
5644 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5645 }
5646 return LTTNG_OK;
5647 }
5648
5649 /*
5650 * Returns a pointer to a handler to run on completion of a command.
5651 * Returns NULL if no handler has to be run for the last command executed.
5652 */
5653 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
5654 {
5655 struct cmd_completion_handler *handler = current_completion_handler;
5656
5657 current_completion_handler = NULL;
5658 return handler;
5659 }
5660
5661 /*
5662 * Init command subsystem.
5663 */
5664 void cmd_init(void)
5665 {
5666 /*
5667 * Set network sequence index to 1 for streams to match a relayd
5668 * socket on the consumer side.
5669 */
5670 pthread_mutex_lock(&relayd_net_seq_idx_lock);
5671 relayd_net_seq_idx = 1;
5672 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
5673
5674 DBG("Command subsystem initialized");
5675 }
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