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Fix: sessiond: crash enabling event rules that differ only by loglevel type
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.cpp
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 "agent-thread.hpp"
11 #include "agent.hpp"
12 #include "buffer-registry.hpp"
13 #include "channel.hpp"
14 #include "cmd.hpp"
15 #include "consumer.hpp"
16 #include "event-notifier-error-accounting.hpp"
17 #include "event.hpp"
18 #include "health-sessiond.hpp"
19 #include "kernel-consumer.hpp"
20 #include "kernel.hpp"
21 #include "lttng-sessiond.hpp"
22 #include "lttng-syscall.hpp"
23 #include "notification-thread-commands.hpp"
24 #include "notification-thread.hpp"
25 #include "rotation-thread.hpp"
26 #include "session.hpp"
27 #include "timer.hpp"
28 #include "tracker.hpp"
29 #include "utils.hpp"
30
31 #include <common/buffer-view.hpp>
32 #include <common/common.hpp>
33 #include <common/compat/string.hpp>
34 #include <common/defaults.hpp>
35 #include <common/dynamic-buffer.hpp>
36 #include <common/kernel-ctl/kernel-ctl.hpp>
37 #include <common/payload-view.hpp>
38 #include <common/payload.hpp>
39 #include <common/relayd/relayd.hpp>
40 #include <common/sessiond-comm/sessiond-comm.hpp>
41 #include <common/string-utils/string-utils.hpp>
42 #include <common/trace-chunk.hpp>
43 #include <common/urcu.hpp>
44 #include <common/utils.hpp>
45
46 #include <lttng/action/action-internal.hpp>
47 #include <lttng/action/action.h>
48 #include <lttng/channel-internal.hpp>
49 #include <lttng/channel.h>
50 #include <lttng/condition/condition-internal.hpp>
51 #include <lttng/condition/condition.h>
52 #include <lttng/condition/event-rule-matches-internal.hpp>
53 #include <lttng/condition/event-rule-matches.h>
54 #include <lttng/error-query-internal.hpp>
55 #include <lttng/event-internal.hpp>
56 #include <lttng/event-rule/event-rule-internal.hpp>
57 #include <lttng/event-rule/event-rule.h>
58 #include <lttng/location-internal.hpp>
59 #include <lttng/lttng-error.h>
60 #include <lttng/rotate-internal.hpp>
61 #include <lttng/session-descriptor-internal.hpp>
62 #include <lttng/session-internal.hpp>
63 #include <lttng/tracker.h>
64 #include <lttng/trigger/trigger-internal.hpp>
65 #include <lttng/userspace-probe-internal.hpp>
66
67 #include <algorithm>
68 #include <inttypes.h>
69 #include <stdio.h>
70 #include <sys/stat.h>
71 #include <urcu/list.h>
72 #include <urcu/uatomic.h>
73
74 /* Sleep for 100ms between each check for the shm path's deletion. */
75 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
76
77 namespace lsu = lttng::sessiond::ust;
78
79 static enum lttng_error_code wait_on_path(void *path);
80
81 namespace {
82 struct cmd_destroy_session_reply_context {
83 int reply_sock_fd;
84 bool implicit_rotation_on_destroy;
85 /*
86 * Indicates whether or not an error occurred while launching the
87 * destruction of a session.
88 */
89 enum lttng_error_code destruction_status;
90 };
91
92 /*
93 * Command completion handler that is used by the destroy command
94 * when a session that has a non-default shm_path is being destroyed.
95 *
96 * See comment in cmd_destroy_session() for the rationale.
97 */
98 struct destroy_completion_handler {
99 struct cmd_completion_handler handler;
100 char shm_path[member_sizeof(struct ltt_session, shm_path)];
101 } destroy_completion_handler = {
102 .handler = { .run = wait_on_path, .data = destroy_completion_handler.shm_path },
103 .shm_path = { 0 },
104 };
105
106 /*
107 * Used to keep a unique index for each relayd socket created where this value
108 * is associated with streams on the consumer so it can match the right relayd
109 * to send to. It must be accessed with the relayd_net_seq_idx_lock
110 * held.
111 */
112 pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
113 uint64_t relayd_net_seq_idx;
114 } /* namespace */
115
116 static struct cmd_completion_handler *current_completion_handler;
117 static int validate_ust_event_name(const char *);
118 static int cmd_enable_event_internal(struct ltt_session *session,
119 const struct lttng_domain *domain,
120 char *channel_name,
121 struct lttng_event *event,
122 char *filter_expression,
123 struct lttng_bytecode *filter,
124 struct lttng_event_exclusion *exclusion,
125 int wpipe);
126 static enum lttng_error_code cmd_enable_channel_internal(struct ltt_session *session,
127 const struct lttng_domain *domain,
128 const struct lttng_channel *_attr,
129 int wpipe);
130
131 /*
132 * Create a session path used by list_lttng_sessions for the case that the
133 * session consumer is on the network.
134 */
135 static int build_network_session_path(char *dst, size_t size, struct ltt_session *session)
136 {
137 int ret, kdata_port, udata_port;
138 struct lttng_uri *kuri = nullptr, *uuri = nullptr, *uri = nullptr;
139 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
140
141 LTTNG_ASSERT(session);
142 LTTNG_ASSERT(dst);
143
144 memset(tmp_urls, 0, sizeof(tmp_urls));
145 memset(tmp_uurl, 0, sizeof(tmp_uurl));
146
147 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
148
149 if (session->kernel_session && session->kernel_session->consumer) {
150 kuri = &session->kernel_session->consumer->dst.net.control;
151 kdata_port = session->kernel_session->consumer->dst.net.data.port;
152 }
153
154 if (session->ust_session && session->ust_session->consumer) {
155 uuri = &session->ust_session->consumer->dst.net.control;
156 udata_port = session->ust_session->consumer->dst.net.data.port;
157 }
158
159 if (uuri == nullptr && kuri == nullptr) {
160 uri = &session->consumer->dst.net.control;
161 kdata_port = session->consumer->dst.net.data.port;
162 } else if (kuri && uuri) {
163 ret = uri_compare(kuri, uuri);
164 if (ret) {
165 /* Not Equal */
166 uri = kuri;
167 /* Build uuri URL string */
168 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
169 if (ret < 0) {
170 goto error;
171 }
172 } else {
173 uri = kuri;
174 }
175 } else if (kuri && uuri == nullptr) {
176 uri = kuri;
177 } else if (uuri && kuri == nullptr) {
178 uri = uuri;
179 }
180
181 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
182 if (ret < 0) {
183 goto error;
184 }
185
186 /*
187 * Do we have a UST url set. If yes, this means we have both kernel and UST
188 * to print.
189 */
190 if (*tmp_uurl != '\0') {
191 ret = snprintf(dst,
192 size,
193 "[K]: %s [data: %d] -- [U]: %s [data: %d]",
194 tmp_urls,
195 kdata_port,
196 tmp_uurl,
197 udata_port);
198 } else {
199 int dport;
200 if (kuri || (!kuri && !uuri)) {
201 dport = kdata_port;
202 } else {
203 /* No kernel URI, use the UST port. */
204 dport = udata_port;
205 }
206 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
207 }
208
209 error:
210 return ret;
211 }
212
213 /*
214 * Get run-time attributes if the session has been started (discarded events,
215 * lost packets).
216 */
217 static int get_kernel_runtime_stats(struct ltt_session *session,
218 struct ltt_kernel_channel *kchan,
219 uint64_t *discarded_events,
220 uint64_t *lost_packets)
221 {
222 int ret;
223
224 if (!session->has_been_started) {
225 ret = 0;
226 *discarded_events = 0;
227 *lost_packets = 0;
228 goto end;
229 }
230
231 ret = consumer_get_discarded_events(
232 session->id, kchan->key, session->kernel_session->consumer, discarded_events);
233 if (ret < 0) {
234 goto end;
235 }
236
237 ret = consumer_get_lost_packets(
238 session->id, kchan->key, session->kernel_session->consumer, lost_packets);
239 if (ret < 0) {
240 goto end;
241 }
242
243 end:
244 return ret;
245 }
246
247 /*
248 * Get run-time attributes if the session has been started (discarded events,
249 * lost packets).
250 */
251 static int get_ust_runtime_stats(struct ltt_session *session,
252 struct ltt_ust_channel *uchan,
253 uint64_t *discarded_events,
254 uint64_t *lost_packets)
255 {
256 int ret;
257 struct ltt_ust_session *usess;
258
259 if (!discarded_events || !lost_packets) {
260 ret = -1;
261 goto end;
262 }
263
264 usess = session->ust_session;
265 LTTNG_ASSERT(discarded_events);
266 LTTNG_ASSERT(lost_packets);
267
268 if (!usess || !session->has_been_started) {
269 *discarded_events = 0;
270 *lost_packets = 0;
271 ret = 0;
272 goto end;
273 }
274
275 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
276 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
277 &usess->buffer_reg_uid_list,
278 usess->consumer,
279 uchan->id,
280 uchan->attr.overwrite,
281 discarded_events,
282 lost_packets);
283 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
284 ret = ust_app_pid_get_channel_runtime_stats(usess,
285 uchan,
286 usess->consumer,
287 uchan->attr.overwrite,
288 discarded_events,
289 lost_packets);
290 if (ret < 0) {
291 goto end;
292 }
293 *discarded_events += uchan->per_pid_closed_app_discarded;
294 *lost_packets += uchan->per_pid_closed_app_lost;
295 } else {
296 ERR("Unsupported buffer type");
297 abort();
298 ret = -1;
299 goto end;
300 }
301
302 end:
303 return ret;
304 }
305
306 /*
307 * Create a list of agent domain events.
308 *
309 * Return number of events in list on success or else a negative value.
310 */
311 static enum lttng_error_code list_lttng_agent_events(struct agent *agt,
312 struct lttng_payload *reply_payload,
313 unsigned int *nb_events)
314 {
315 enum lttng_error_code ret_code;
316 int ret = 0;
317 unsigned int local_nb_events = 0;
318 struct agent_event *event;
319 struct lttng_ht_iter iter;
320 unsigned long agent_event_count;
321
322 assert(agt);
323 assert(reply_payload);
324
325 DBG3("Listing agent events");
326
327 agent_event_count = lttng_ht_get_count(agt->events);
328 if (agent_event_count == 0) {
329 /* Early exit. */
330 goto end;
331 }
332
333 if (agent_event_count > UINT_MAX) {
334 ret_code = LTTNG_ERR_OVERFLOW;
335 goto error;
336 }
337
338 local_nb_events = (unsigned int) agent_event_count;
339
340 {
341 lttng::urcu::read_lock_guard read_lock;
342
343 cds_lfht_for_each_entry (agt->events->ht, &iter.iter, event, node.node) {
344 struct lttng_event *tmp_event = lttng_event_create();
345
346 if (!tmp_event) {
347 ret_code = LTTNG_ERR_NOMEM;
348 goto error;
349 }
350
351 if (lttng_strncpy(tmp_event->name, event->name, sizeof(tmp_event->name))) {
352 lttng_event_destroy(tmp_event);
353 ret_code = LTTNG_ERR_FATAL;
354 goto error;
355 }
356
357 tmp_event->name[sizeof(tmp_event->name) - 1] = '\0';
358 tmp_event->enabled = !!event->enabled_count;
359 tmp_event->loglevel = event->loglevel_value;
360 tmp_event->loglevel_type = event->loglevel_type;
361
362 ret = lttng_event_serialize(tmp_event,
363 0,
364 nullptr,
365 event->filter_expression,
366 0,
367 nullptr,
368 reply_payload);
369 lttng_event_destroy(tmp_event);
370 if (ret) {
371 ret_code = LTTNG_ERR_FATAL;
372 goto error;
373 }
374 }
375 }
376 end:
377 ret_code = LTTNG_OK;
378 *nb_events = local_nb_events;
379 error:
380 return ret_code;
381 }
382
383 /*
384 * Create a list of ust global domain events.
385 */
386 static enum lttng_error_code list_lttng_ust_global_events(char *channel_name,
387 struct ltt_ust_domain_global *ust_global,
388 struct lttng_payload *reply_payload,
389 unsigned int *nb_events)
390 {
391 enum lttng_error_code ret_code;
392 int ret;
393 struct lttng_ht_iter iter;
394 struct lttng_ht_node_str *node;
395 struct ltt_ust_channel *uchan;
396 struct ltt_ust_event *uevent;
397 unsigned long channel_event_count;
398 unsigned int local_nb_events = 0;
399
400 assert(reply_payload);
401 assert(nb_events);
402
403 DBG("Listing UST global events for channel %s", channel_name);
404
405 lttng::urcu::read_lock_guard read_lock;
406
407 lttng_ht_lookup(ust_global->channels, (void *) channel_name, &iter);
408 node = lttng_ht_iter_get_node_str(&iter);
409 if (node == nullptr) {
410 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
411 goto error;
412 }
413
414 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
415
416 channel_event_count = lttng_ht_get_count(uchan->events);
417 if (channel_event_count == 0) {
418 /* Early exit. */
419 ret_code = LTTNG_OK;
420 goto end;
421 }
422
423 if (channel_event_count > UINT_MAX) {
424 ret_code = LTTNG_ERR_OVERFLOW;
425 goto error;
426 }
427
428 local_nb_events = (unsigned int) channel_event_count;
429
430 DBG3("Listing UST global %d events", *nb_events);
431
432 cds_lfht_for_each_entry (uchan->events->ht, &iter.iter, uevent, node.node) {
433 struct lttng_event *tmp_event = nullptr;
434
435 if (uevent->internal) {
436 /* This event should remain hidden from clients */
437 local_nb_events--;
438 continue;
439 }
440
441 tmp_event = lttng_event_create();
442 if (!tmp_event) {
443 ret_code = LTTNG_ERR_NOMEM;
444 goto error;
445 }
446
447 if (lttng_strncpy(tmp_event->name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN)) {
448 ret_code = LTTNG_ERR_FATAL;
449 lttng_event_destroy(tmp_event);
450 goto error;
451 }
452
453 tmp_event->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
454 tmp_event->enabled = uevent->enabled;
455
456 switch (uevent->attr.instrumentation) {
457 case LTTNG_UST_ABI_TRACEPOINT:
458 tmp_event->type = LTTNG_EVENT_TRACEPOINT;
459 break;
460 case LTTNG_UST_ABI_PROBE:
461 tmp_event->type = LTTNG_EVENT_PROBE;
462 break;
463 case LTTNG_UST_ABI_FUNCTION:
464 tmp_event->type = LTTNG_EVENT_FUNCTION;
465 break;
466 }
467
468 tmp_event->loglevel = uevent->attr.loglevel;
469 switch (uevent->attr.loglevel_type) {
470 case LTTNG_UST_ABI_LOGLEVEL_ALL:
471 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
472 break;
473 case LTTNG_UST_ABI_LOGLEVEL_RANGE:
474 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
475 break;
476 case LTTNG_UST_ABI_LOGLEVEL_SINGLE:
477 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
478 break;
479 }
480 if (uevent->filter) {
481 tmp_event->filter = 1;
482 }
483 if (uevent->exclusion) {
484 tmp_event->exclusion = 1;
485 }
486
487 std::vector<const char *> exclusion_names;
488 if (uevent->exclusion) {
489 for (int i = 0; i < uevent->exclusion->count; i++) {
490 exclusion_names.emplace_back(
491 LTTNG_EVENT_EXCLUSION_NAME_AT(uevent->exclusion, i));
492 }
493 }
494
495 /*
496 * We do not care about the filter bytecode and the fd from the
497 * userspace_probe_location.
498 */
499 ret = lttng_event_serialize(tmp_event,
500 exclusion_names.size(),
501 exclusion_names.size() ? exclusion_names.data() :
502 nullptr,
503 uevent->filter_expression,
504 0,
505 nullptr,
506 reply_payload);
507 lttng_event_destroy(tmp_event);
508 if (ret) {
509 ret_code = LTTNG_ERR_FATAL;
510 goto error;
511 }
512 }
513
514 end:
515 /* nb_events is already set at this point. */
516 ret_code = LTTNG_OK;
517 *nb_events = local_nb_events;
518 error:
519 return ret_code;
520 }
521
522 /*
523 * Fill lttng_event array of all kernel events in the channel.
524 */
525 static enum lttng_error_code list_lttng_kernel_events(char *channel_name,
526 struct ltt_kernel_session *kernel_session,
527 struct lttng_payload *reply_payload,
528 unsigned int *nb_events)
529 {
530 enum lttng_error_code ret_code;
531 int ret;
532 struct ltt_kernel_event *event;
533 struct ltt_kernel_channel *kchan;
534
535 assert(reply_payload);
536
537 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
538 if (kchan == nullptr) {
539 ret_code = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
540 goto end;
541 }
542
543 *nb_events = kchan->event_count;
544
545 DBG("Listing events for channel %s", kchan->channel->name);
546
547 if (*nb_events == 0) {
548 ret_code = LTTNG_OK;
549 goto end;
550 }
551
552 /* Kernel channels */
553 cds_list_for_each_entry (event, &kchan->events_list.head, list) {
554 struct lttng_event *tmp_event = lttng_event_create();
555
556 if (!tmp_event) {
557 ret_code = LTTNG_ERR_NOMEM;
558 goto end;
559 }
560
561 if (lttng_strncpy(tmp_event->name, event->event->name, LTTNG_SYMBOL_NAME_LEN)) {
562 lttng_event_destroy(tmp_event);
563 ret_code = LTTNG_ERR_FATAL;
564 goto end;
565 }
566
567 tmp_event->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
568 tmp_event->enabled = event->enabled;
569 tmp_event->filter = (unsigned char) !!event->filter_expression;
570
571 switch (event->event->instrumentation) {
572 case LTTNG_KERNEL_ABI_TRACEPOINT:
573 tmp_event->type = LTTNG_EVENT_TRACEPOINT;
574 break;
575 case LTTNG_KERNEL_ABI_KRETPROBE:
576 tmp_event->type = LTTNG_EVENT_FUNCTION;
577 memcpy(&tmp_event->attr.probe,
578 &event->event->u.kprobe,
579 sizeof(struct lttng_kernel_abi_kprobe));
580 break;
581 case LTTNG_KERNEL_ABI_KPROBE:
582 tmp_event->type = LTTNG_EVENT_PROBE;
583 memcpy(&tmp_event->attr.probe,
584 &event->event->u.kprobe,
585 sizeof(struct lttng_kernel_abi_kprobe));
586 break;
587 case LTTNG_KERNEL_ABI_UPROBE:
588 tmp_event->type = LTTNG_EVENT_USERSPACE_PROBE;
589 break;
590 case LTTNG_KERNEL_ABI_FUNCTION:
591 tmp_event->type = LTTNG_EVENT_FUNCTION;
592 memcpy(&(tmp_event->attr.ftrace),
593 &event->event->u.ftrace,
594 sizeof(struct lttng_kernel_abi_function));
595 break;
596 case LTTNG_KERNEL_ABI_NOOP:
597 tmp_event->type = LTTNG_EVENT_NOOP;
598 break;
599 case LTTNG_KERNEL_ABI_SYSCALL:
600 tmp_event->type = LTTNG_EVENT_SYSCALL;
601 break;
602 case LTTNG_KERNEL_ABI_ALL:
603 /* fall-through. */
604 default:
605 abort();
606 break;
607 }
608
609 if (event->userspace_probe_location) {
610 struct lttng_userspace_probe_location *location_copy =
611 lttng_userspace_probe_location_copy(
612 event->userspace_probe_location);
613
614 if (!location_copy) {
615 lttng_event_destroy(tmp_event);
616 ret_code = LTTNG_ERR_NOMEM;
617 goto end;
618 }
619
620 ret = lttng_event_set_userspace_probe_location(tmp_event, location_copy);
621 if (ret) {
622 lttng_event_destroy(tmp_event);
623 lttng_userspace_probe_location_destroy(location_copy);
624 ret_code = LTTNG_ERR_INVALID;
625 goto end;
626 }
627 }
628
629 ret = lttng_event_serialize(
630 tmp_event, 0, nullptr, event->filter_expression, 0, nullptr, reply_payload);
631 lttng_event_destroy(tmp_event);
632 if (ret) {
633 ret_code = LTTNG_ERR_FATAL;
634 goto end;
635 }
636 }
637
638 ret_code = LTTNG_OK;
639 end:
640 return ret_code;
641 }
642
643 /*
644 * Add URI so the consumer output object. Set the correct path depending on the
645 * domain adding the default trace directory.
646 */
647 static enum lttng_error_code add_uri_to_consumer(const struct ltt_session *session,
648 struct consumer_output *consumer,
649 struct lttng_uri *uri,
650 enum lttng_domain_type domain)
651 {
652 int ret;
653 enum lttng_error_code ret_code = LTTNG_OK;
654
655 LTTNG_ASSERT(uri);
656
657 if (consumer == nullptr) {
658 DBG("No consumer detected. Don't add URI. Stopping.");
659 ret_code = LTTNG_ERR_NO_CONSUMER;
660 goto error;
661 }
662
663 switch (domain) {
664 case LTTNG_DOMAIN_KERNEL:
665 ret = lttng_strncpy(consumer->domain_subdir,
666 DEFAULT_KERNEL_TRACE_DIR,
667 sizeof(consumer->domain_subdir));
668 break;
669 case LTTNG_DOMAIN_UST:
670 ret = lttng_strncpy(consumer->domain_subdir,
671 DEFAULT_UST_TRACE_DIR,
672 sizeof(consumer->domain_subdir));
673 break;
674 default:
675 /*
676 * This case is possible is we try to add the URI to the global
677 * tracing session consumer object which in this case there is
678 * no subdir.
679 */
680 memset(consumer->domain_subdir, 0, sizeof(consumer->domain_subdir));
681 ret = 0;
682 }
683 if (ret) {
684 ERR("Failed to initialize consumer output domain subdirectory");
685 ret_code = LTTNG_ERR_FATAL;
686 goto error;
687 }
688
689 switch (uri->dtype) {
690 case LTTNG_DST_IPV4:
691 case LTTNG_DST_IPV6:
692 DBG2("Setting network URI to consumer");
693
694 if (consumer->type == CONSUMER_DST_NET) {
695 if ((uri->stype == LTTNG_STREAM_CONTROL &&
696 consumer->dst.net.control_isset) ||
697 (uri->stype == LTTNG_STREAM_DATA && consumer->dst.net.data_isset)) {
698 ret_code = LTTNG_ERR_URL_EXIST;
699 goto error;
700 }
701 } else {
702 memset(&consumer->dst, 0, sizeof(consumer->dst));
703 }
704
705 /* Set URI into consumer output object */
706 ret = consumer_set_network_uri(session, consumer, uri);
707 if (ret < 0) {
708 ret_code = (lttng_error_code) -ret;
709 goto error;
710 } else if (ret == 1) {
711 /*
712 * URI was the same in the consumer so we do not append the subdir
713 * again so to not duplicate output dir.
714 */
715 ret_code = LTTNG_OK;
716 goto error;
717 }
718 break;
719 case LTTNG_DST_PATH:
720 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
721 ret_code = LTTNG_ERR_INVALID;
722 goto error;
723 }
724 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
725 memset(&consumer->dst, 0, sizeof(consumer->dst));
726
727 ret = lttng_strncpy(consumer->dst.session_root_path,
728 uri->dst.path,
729 sizeof(consumer->dst.session_root_path));
730 if (ret) {
731 ret_code = LTTNG_ERR_FATAL;
732 goto error;
733 }
734 consumer->type = CONSUMER_DST_LOCAL;
735 break;
736 }
737
738 ret_code = LTTNG_OK;
739 error:
740 return ret_code;
741 }
742
743 /*
744 * Init tracing by creating trace directory and sending fds kernel consumer.
745 */
746 static int init_kernel_tracing(struct ltt_kernel_session *session)
747 {
748 int ret = 0;
749 struct lttng_ht_iter iter;
750 struct consumer_socket *socket;
751
752 LTTNG_ASSERT(session);
753
754 if (session->consumer_fds_sent == 0 && session->consumer != nullptr) {
755 lttng::urcu::read_lock_guard read_lock;
756
757 cds_lfht_for_each_entry (
758 session->consumer->socks->ht, &iter.iter, socket, node.node) {
759 pthread_mutex_lock(socket->lock);
760 ret = kernel_consumer_send_session(socket, session);
761 pthread_mutex_unlock(socket->lock);
762 if (ret < 0) {
763 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
764 goto error;
765 }
766 }
767 }
768
769 error:
770 return ret;
771 }
772
773 /*
774 * Create a socket to the relayd using the URI.
775 *
776 * On success, the relayd_sock pointer is set to the created socket.
777 * Else, it remains untouched and an LTTng error code is returned.
778 */
779 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
780 struct lttcomm_relayd_sock **relayd_sock,
781 struct consumer_output *consumer)
782 {
783 int ret;
784 enum lttng_error_code status = LTTNG_OK;
785 struct lttcomm_relayd_sock *rsock;
786
787 rsock = lttcomm_alloc_relayd_sock(
788 uri, RELAYD_VERSION_COMM_MAJOR, RELAYD_VERSION_COMM_MINOR);
789 if (!rsock) {
790 status = LTTNG_ERR_FATAL;
791 goto error;
792 }
793
794 /*
795 * Connect to relayd so we can proceed with a session creation. This call
796 * can possibly block for an arbitrary amount of time to set the health
797 * state to be in poll execution.
798 */
799 health_poll_entry();
800 ret = relayd_connect(rsock);
801 health_poll_exit();
802 if (ret < 0) {
803 ERR("Unable to reach lttng-relayd");
804 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
805 goto free_sock;
806 }
807
808 /* Create socket for control stream. */
809 if (uri->stype == LTTNG_STREAM_CONTROL) {
810 uint64_t result_flags;
811
812 DBG3("Creating relayd stream socket from URI");
813
814 /* Check relayd version */
815 ret = relayd_version_check(rsock);
816 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
817 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
818 goto close_sock;
819 } else if (ret < 0) {
820 ERR("Unable to reach lttng-relayd");
821 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
822 goto close_sock;
823 }
824 consumer->relay_major_version = rsock->major;
825 consumer->relay_minor_version = rsock->minor;
826 ret = relayd_get_configuration(rsock, 0, &result_flags);
827 if (ret < 0) {
828 ERR("Unable to get relayd configuration");
829 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
830 goto close_sock;
831 }
832 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
833 consumer->relay_allows_clear = true;
834 }
835 } else if (uri->stype == LTTNG_STREAM_DATA) {
836 DBG3("Creating relayd data socket from URI");
837 } else {
838 /* Command is not valid */
839 ERR("Relayd invalid stream type: %d", uri->stype);
840 status = LTTNG_ERR_INVALID;
841 goto close_sock;
842 }
843
844 *relayd_sock = rsock;
845
846 return status;
847
848 close_sock:
849 /* The returned value is not useful since we are on an error path. */
850 (void) relayd_close(rsock);
851 free_sock:
852 free(rsock);
853 error:
854 return status;
855 }
856
857 /*
858 * Connect to the relayd using URI and send the socket to the right consumer.
859 *
860 * The consumer socket lock must be held by the caller.
861 *
862 * Returns LTTNG_OK on success or an LTTng error code on failure.
863 */
864 static enum lttng_error_code send_consumer_relayd_socket(unsigned int session_id,
865 struct lttng_uri *relayd_uri,
866 struct consumer_output *consumer,
867 struct consumer_socket *consumer_sock,
868 const char *session_name,
869 const char *hostname,
870 const char *base_path,
871 int session_live_timer,
872 const uint64_t *current_chunk_id,
873 time_t session_creation_time,
874 bool session_name_contains_creation_time)
875 {
876 int ret;
877 struct lttcomm_relayd_sock *rsock = nullptr;
878 enum lttng_error_code status;
879
880 /* Connect to relayd and make version check if uri is the control. */
881 status = create_connect_relayd(relayd_uri, &rsock, consumer);
882 if (status != LTTNG_OK) {
883 goto relayd_comm_error;
884 }
885 LTTNG_ASSERT(rsock);
886
887 /* Set the network sequence index if not set. */
888 if (consumer->net_seq_index == (uint64_t) -1ULL) {
889 pthread_mutex_lock(&relayd_net_seq_idx_lock);
890 /*
891 * Increment net_seq_idx because we are about to transfer the
892 * new relayd socket to the consumer.
893 * Assign unique key so the consumer can match streams.
894 */
895 consumer->net_seq_index = ++relayd_net_seq_idx;
896 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
897 }
898
899 /* Send relayd socket to consumer. */
900 ret = consumer_send_relayd_socket(consumer_sock,
901 rsock,
902 consumer,
903 relayd_uri->stype,
904 session_id,
905 session_name,
906 hostname,
907 base_path,
908 session_live_timer,
909 current_chunk_id,
910 session_creation_time,
911 session_name_contains_creation_time);
912 if (ret < 0) {
913 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
914 goto close_sock;
915 }
916
917 /* Flag that the corresponding socket was sent. */
918 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
919 consumer_sock->control_sock_sent = 1;
920 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
921 consumer_sock->data_sock_sent = 1;
922 }
923
924 /*
925 * Close socket which was dup on the consumer side. The session daemon does
926 * NOT keep track of the relayd socket(s) once transfer to the consumer.
927 */
928
929 close_sock:
930 if (status != LTTNG_OK) {
931 /*
932 * The consumer output for this session should not be used anymore
933 * since the relayd connection failed thus making any tracing or/and
934 * streaming not usable.
935 */
936 consumer->enabled = false;
937 }
938 (void) relayd_close(rsock);
939 free(rsock);
940
941 relayd_comm_error:
942 return status;
943 }
944
945 /*
946 * Send both relayd sockets to a specific consumer and domain. This is a
947 * helper function to facilitate sending the information to the consumer for a
948 * session.
949 *
950 * The consumer socket lock must be held by the caller.
951 *
952 * Returns LTTNG_OK, or an LTTng error code on failure.
953 */
954 static enum lttng_error_code send_consumer_relayd_sockets(unsigned int session_id,
955 struct consumer_output *consumer,
956 struct consumer_socket *sock,
957 const char *session_name,
958 const char *hostname,
959 const char *base_path,
960 int session_live_timer,
961 const uint64_t *current_chunk_id,
962 time_t session_creation_time,
963 bool session_name_contains_creation_time)
964 {
965 enum lttng_error_code status = LTTNG_OK;
966
967 LTTNG_ASSERT(consumer);
968 LTTNG_ASSERT(sock);
969
970 /* Sending control relayd socket. */
971 if (!sock->control_sock_sent) {
972 status = send_consumer_relayd_socket(session_id,
973 &consumer->dst.net.control,
974 consumer,
975 sock,
976 session_name,
977 hostname,
978 base_path,
979 session_live_timer,
980 current_chunk_id,
981 session_creation_time,
982 session_name_contains_creation_time);
983 if (status != LTTNG_OK) {
984 goto error;
985 }
986 }
987
988 /* Sending data relayd socket. */
989 if (!sock->data_sock_sent) {
990 status = send_consumer_relayd_socket(session_id,
991 &consumer->dst.net.data,
992 consumer,
993 sock,
994 session_name,
995 hostname,
996 base_path,
997 session_live_timer,
998 current_chunk_id,
999 session_creation_time,
1000 session_name_contains_creation_time);
1001 if (status != LTTNG_OK) {
1002 goto error;
1003 }
1004 }
1005
1006 error:
1007 return status;
1008 }
1009
1010 /*
1011 * Setup relayd connections for a tracing session. First creates the socket to
1012 * the relayd and send them to the right domain consumer. Consumer type MUST be
1013 * network.
1014 */
1015 int cmd_setup_relayd(struct ltt_session *session)
1016 {
1017 int ret = LTTNG_OK;
1018 struct ltt_ust_session *usess;
1019 struct ltt_kernel_session *ksess;
1020 struct consumer_socket *socket;
1021 struct lttng_ht_iter iter;
1022 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1023
1024 LTTNG_ASSERT(session);
1025
1026 usess = session->ust_session;
1027 ksess = session->kernel_session;
1028
1029 DBG("Setting relayd for session %s", session->name);
1030
1031 if (session->current_trace_chunk) {
1032 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1033 session->current_trace_chunk, &current_chunk_id.value);
1034
1035 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1036 current_chunk_id.is_set = true;
1037 } else {
1038 ERR("Failed to get current trace chunk id");
1039 ret = LTTNG_ERR_UNK;
1040 goto error;
1041 }
1042 }
1043
1044 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET &&
1045 usess->consumer->enabled) {
1046 /* For each consumer socket, send relayd sockets */
1047 lttng::urcu::read_lock_guard read_lock;
1048
1049 cds_lfht_for_each_entry (
1050 usess->consumer->socks->ht, &iter.iter, socket, node.node) {
1051 pthread_mutex_lock(socket->lock);
1052 ret = send_consumer_relayd_sockets(
1053 session->id,
1054 usess->consumer,
1055 socket,
1056 session->name,
1057 session->hostname,
1058 session->base_path,
1059 session->live_timer,
1060 current_chunk_id.is_set ? &current_chunk_id.value : nullptr,
1061 session->creation_time,
1062 session->name_contains_creation_time);
1063 pthread_mutex_unlock(socket->lock);
1064 if (ret != LTTNG_OK) {
1065 goto error;
1066 }
1067 /* Session is now ready for network streaming. */
1068 session->net_handle = 1;
1069 }
1070
1071 session->consumer->relay_major_version = usess->consumer->relay_major_version;
1072 session->consumer->relay_minor_version = usess->consumer->relay_minor_version;
1073 session->consumer->relay_allows_clear = usess->consumer->relay_allows_clear;
1074 }
1075
1076 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET &&
1077 ksess->consumer->enabled) {
1078 lttng::urcu::read_lock_guard read_lock;
1079
1080 cds_lfht_for_each_entry (
1081 ksess->consumer->socks->ht, &iter.iter, socket, node.node) {
1082 pthread_mutex_lock(socket->lock);
1083 ret = send_consumer_relayd_sockets(
1084 session->id,
1085 ksess->consumer,
1086 socket,
1087 session->name,
1088 session->hostname,
1089 session->base_path,
1090 session->live_timer,
1091 current_chunk_id.is_set ? &current_chunk_id.value : nullptr,
1092 session->creation_time,
1093 session->name_contains_creation_time);
1094 pthread_mutex_unlock(socket->lock);
1095 if (ret != LTTNG_OK) {
1096 goto error;
1097 }
1098 /* Session is now ready for network streaming. */
1099 session->net_handle = 1;
1100 }
1101
1102 session->consumer->relay_major_version = ksess->consumer->relay_major_version;
1103 session->consumer->relay_minor_version = ksess->consumer->relay_minor_version;
1104 session->consumer->relay_allows_clear = ksess->consumer->relay_allows_clear;
1105 }
1106
1107 error:
1108 return ret;
1109 }
1110
1111 /*
1112 * Start a kernel session by opening all necessary streams.
1113 */
1114 int start_kernel_session(struct ltt_kernel_session *ksess)
1115 {
1116 int ret;
1117 struct ltt_kernel_channel *kchan;
1118
1119 /* Open kernel metadata */
1120 if (ksess->metadata == nullptr && ksess->output_traces) {
1121 ret = kernel_open_metadata(ksess);
1122 if (ret < 0) {
1123 ret = LTTNG_ERR_KERN_META_FAIL;
1124 goto error;
1125 }
1126 }
1127
1128 /* Open kernel metadata stream */
1129 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1130 ret = kernel_open_metadata_stream(ksess);
1131 if (ret < 0) {
1132 ERR("Kernel create metadata stream failed");
1133 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1134 goto error;
1135 }
1136 }
1137
1138 /* For each channel */
1139 cds_list_for_each_entry (kchan, &ksess->channel_list.head, list) {
1140 if (kchan->stream_count == 0) {
1141 ret = kernel_open_channel_stream(kchan);
1142 if (ret < 0) {
1143 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1144 goto error;
1145 }
1146 /* Update the stream global counter */
1147 ksess->stream_count_global += ret;
1148 }
1149 }
1150
1151 /* Setup kernel consumer socket and send fds to it */
1152 ret = init_kernel_tracing(ksess);
1153 if (ret != 0) {
1154 ret = LTTNG_ERR_KERN_START_FAIL;
1155 goto error;
1156 }
1157
1158 /* This start the kernel tracing */
1159 ret = kernel_start_session(ksess);
1160 if (ret < 0) {
1161 ret = LTTNG_ERR_KERN_START_FAIL;
1162 goto error;
1163 }
1164
1165 /* Quiescent wait after starting trace */
1166 kernel_wait_quiescent();
1167
1168 ksess->active = true;
1169
1170 ret = LTTNG_OK;
1171
1172 error:
1173 return ret;
1174 }
1175
1176 int stop_kernel_session(struct ltt_kernel_session *ksess)
1177 {
1178 struct ltt_kernel_channel *kchan;
1179 bool error_occurred = false;
1180 int ret;
1181
1182 if (!ksess || !ksess->active) {
1183 return LTTNG_OK;
1184 }
1185 DBG("Stopping kernel tracing");
1186
1187 ret = kernel_stop_session(ksess);
1188 if (ret < 0) {
1189 ret = LTTNG_ERR_KERN_STOP_FAIL;
1190 goto error;
1191 }
1192
1193 kernel_wait_quiescent();
1194
1195 /* Flush metadata after stopping (if exists) */
1196 if (ksess->metadata_stream_fd >= 0) {
1197 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1198 if (ret < 0) {
1199 ERR("Kernel metadata flush failed");
1200 error_occurred = true;
1201 }
1202 }
1203
1204 /* Flush all buffers after stopping */
1205 cds_list_for_each_entry (kchan, &ksess->channel_list.head, list) {
1206 ret = kernel_flush_buffer(kchan);
1207 if (ret < 0) {
1208 ERR("Kernel flush buffer error");
1209 error_occurred = true;
1210 }
1211 }
1212
1213 ksess->active = false;
1214 if (error_occurred) {
1215 ret = LTTNG_ERR_UNK;
1216 } else {
1217 ret = LTTNG_OK;
1218 }
1219 error:
1220 return ret;
1221 }
1222
1223 /*
1224 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1225 */
1226 int cmd_disable_channel(struct ltt_session *session,
1227 enum lttng_domain_type domain,
1228 char *channel_name)
1229 {
1230 int ret;
1231 struct ltt_ust_session *usess;
1232
1233 usess = session->ust_session;
1234
1235 lttng::urcu::read_lock_guard read_lock;
1236
1237 switch (domain) {
1238 case LTTNG_DOMAIN_KERNEL:
1239 {
1240 ret = channel_kernel_disable(session->kernel_session, channel_name);
1241 if (ret != LTTNG_OK) {
1242 goto error;
1243 }
1244
1245 kernel_wait_quiescent();
1246 break;
1247 }
1248 case LTTNG_DOMAIN_UST:
1249 {
1250 struct ltt_ust_channel *uchan;
1251 struct lttng_ht *chan_ht;
1252
1253 chan_ht = usess->domain_global.channels;
1254
1255 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1256 if (uchan == nullptr) {
1257 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1258 goto error;
1259 }
1260
1261 ret = channel_ust_disable(usess, uchan);
1262 if (ret != LTTNG_OK) {
1263 goto error;
1264 }
1265 break;
1266 }
1267 default:
1268 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1269 goto error;
1270 }
1271
1272 ret = LTTNG_OK;
1273
1274 error:
1275 return ret;
1276 }
1277
1278 /*
1279 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1280 *
1281 * The wpipe arguments is used as a notifier for the kernel thread.
1282 */
1283 int cmd_enable_channel(struct command_ctx *cmd_ctx, int sock, int wpipe)
1284 {
1285 int ret;
1286 size_t channel_len;
1287 ssize_t sock_recv_len;
1288 struct lttng_channel *channel = nullptr;
1289 struct lttng_buffer_view view;
1290 struct lttng_dynamic_buffer channel_buffer;
1291 const struct lttng_domain command_domain = cmd_ctx->lsm.domain;
1292
1293 lttng_dynamic_buffer_init(&channel_buffer);
1294 channel_len = (size_t) cmd_ctx->lsm.u.channel.length;
1295 ret = lttng_dynamic_buffer_set_size(&channel_buffer, channel_len);
1296 if (ret) {
1297 ret = LTTNG_ERR_NOMEM;
1298 goto end;
1299 }
1300
1301 sock_recv_len = lttcomm_recv_unix_sock(sock, channel_buffer.data, channel_len);
1302 if (sock_recv_len < 0 || sock_recv_len != channel_len) {
1303 ERR("Failed to receive \"enable channel\" command payload");
1304 ret = LTTNG_ERR_INVALID;
1305 goto end;
1306 }
1307
1308 view = lttng_buffer_view_from_dynamic_buffer(&channel_buffer, 0, channel_len);
1309 if (!lttng_buffer_view_is_valid(&view)) {
1310 ret = LTTNG_ERR_INVALID;
1311 goto end;
1312 }
1313
1314 if (lttng_channel_create_from_buffer(&view, &channel) != channel_len) {
1315 ERR("Invalid channel payload received in \"enable channel\" command");
1316 ret = LTTNG_ERR_INVALID;
1317 goto end;
1318 }
1319
1320 ret = cmd_enable_channel_internal(cmd_ctx->session, &command_domain, channel, wpipe);
1321
1322 end:
1323 lttng_dynamic_buffer_reset(&channel_buffer);
1324 lttng_channel_destroy(channel);
1325 return ret;
1326 }
1327
1328 static enum lttng_error_code cmd_enable_channel_internal(struct ltt_session *session,
1329 const struct lttng_domain *domain,
1330 const struct lttng_channel *_attr,
1331 int wpipe)
1332 {
1333 enum lttng_error_code ret_code;
1334 struct ltt_ust_session *usess = session->ust_session;
1335 struct lttng_ht *chan_ht;
1336 size_t len;
1337 struct lttng_channel *attr = nullptr;
1338
1339 LTTNG_ASSERT(session);
1340 LTTNG_ASSERT(_attr);
1341 LTTNG_ASSERT(domain);
1342
1343 lttng::urcu::read_lock_guard read_lock;
1344
1345 attr = lttng_channel_copy(_attr);
1346 if (!attr) {
1347 ret_code = LTTNG_ERR_NOMEM;
1348 goto end;
1349 }
1350
1351 len = lttng_strnlen(attr->name, sizeof(attr->name));
1352
1353 /* Validate channel name */
1354 if (attr->name[0] == '.' || memchr(attr->name, '/', len) != nullptr) {
1355 ret_code = LTTNG_ERR_INVALID_CHANNEL_NAME;
1356 goto end;
1357 }
1358
1359 DBG("Enabling channel %s for session %s", attr->name, session->name);
1360
1361 /*
1362 * If the session is a live session, remove the switch timer, the
1363 * live timer does the same thing but sends also synchronisation
1364 * beacons for inactive streams.
1365 */
1366 if (session->live_timer > 0) {
1367 attr->attr.live_timer_interval = session->live_timer;
1368 attr->attr.switch_timer_interval = 0;
1369 }
1370
1371 /* Check for feature support */
1372 switch (domain->type) {
1373 case LTTNG_DOMAIN_KERNEL:
1374 {
1375 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1376 /* Sampling position of buffer is not supported */
1377 WARN("Kernel tracer does not support buffer monitoring. "
1378 "Setting the monitor interval timer to 0 "
1379 "(disabled) for channel '%s' of session '%s'",
1380 attr->name,
1381 session->name);
1382 lttng_channel_set_monitor_timer_interval(attr, 0);
1383 }
1384 break;
1385 }
1386 case LTTNG_DOMAIN_UST:
1387 break;
1388 case LTTNG_DOMAIN_JUL:
1389 case LTTNG_DOMAIN_LOG4J:
1390 case LTTNG_DOMAIN_PYTHON:
1391 if (!agent_tracing_is_enabled()) {
1392 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1393 ret_code = LTTNG_ERR_AGENT_TRACING_DISABLED;
1394 goto error;
1395 }
1396 break;
1397 default:
1398 ret_code = LTTNG_ERR_UNKNOWN_DOMAIN;
1399 goto error;
1400 }
1401
1402 switch (domain->type) {
1403 case LTTNG_DOMAIN_KERNEL:
1404 {
1405 struct ltt_kernel_channel *kchan;
1406
1407 kchan = trace_kernel_get_channel_by_name(attr->name, session->kernel_session);
1408 if (kchan == nullptr) {
1409 /*
1410 * Don't try to create a channel if the session has been started at
1411 * some point in time before. The tracer does not allow it.
1412 */
1413 if (session->has_been_started) {
1414 ret_code = LTTNG_ERR_TRACE_ALREADY_STARTED;
1415 goto error;
1416 }
1417
1418 if (session->snapshot.nb_output > 0 || session->snapshot_mode) {
1419 /* Enforce mmap output for snapshot sessions. */
1420 attr->attr.output = LTTNG_EVENT_MMAP;
1421 }
1422 ret_code = channel_kernel_create(session->kernel_session, attr, wpipe);
1423 if (attr->name[0] != '\0') {
1424 session->kernel_session->has_non_default_channel = 1;
1425 }
1426 } else {
1427 ret_code = channel_kernel_enable(session->kernel_session, kchan);
1428 }
1429
1430 if (ret_code != LTTNG_OK) {
1431 goto error;
1432 }
1433
1434 kernel_wait_quiescent();
1435 break;
1436 }
1437 case LTTNG_DOMAIN_UST:
1438 case LTTNG_DOMAIN_JUL:
1439 case LTTNG_DOMAIN_LOG4J:
1440 case LTTNG_DOMAIN_PYTHON:
1441 {
1442 struct ltt_ust_channel *uchan;
1443
1444 /*
1445 * FIXME
1446 *
1447 * Current agent implementation limitations force us to allow
1448 * only one channel at once in "agent" subdomains. Each
1449 * subdomain has a default channel name which must be strictly
1450 * adhered to.
1451 */
1452 if (domain->type == LTTNG_DOMAIN_JUL) {
1453 if (strncmp(attr->name,
1454 DEFAULT_JUL_CHANNEL_NAME,
1455 LTTNG_SYMBOL_NAME_LEN - 1) != 0) {
1456 ret_code = LTTNG_ERR_INVALID_CHANNEL_NAME;
1457 goto error;
1458 }
1459 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1460 if (strncmp(attr->name,
1461 DEFAULT_LOG4J_CHANNEL_NAME,
1462 LTTNG_SYMBOL_NAME_LEN - 1) != 0) {
1463 ret_code = LTTNG_ERR_INVALID_CHANNEL_NAME;
1464 goto error;
1465 }
1466 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1467 if (strncmp(attr->name,
1468 DEFAULT_PYTHON_CHANNEL_NAME,
1469 LTTNG_SYMBOL_NAME_LEN - 1) != 0) {
1470 ret_code = LTTNG_ERR_INVALID_CHANNEL_NAME;
1471 goto error;
1472 }
1473 }
1474
1475 chan_ht = usess->domain_global.channels;
1476
1477 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1478 if (uchan == nullptr) {
1479 /*
1480 * Don't try to create a channel if the session has been started at
1481 * some point in time before. The tracer does not allow it.
1482 */
1483 if (session->has_been_started) {
1484 ret_code = LTTNG_ERR_TRACE_ALREADY_STARTED;
1485 goto error;
1486 }
1487
1488 ret_code = channel_ust_create(usess, attr, domain->buf_type);
1489 if (attr->name[0] != '\0') {
1490 usess->has_non_default_channel = 1;
1491 }
1492 } else {
1493 ret_code = channel_ust_enable(usess, uchan);
1494 }
1495 break;
1496 }
1497 default:
1498 ret_code = LTTNG_ERR_UNKNOWN_DOMAIN;
1499 goto error;
1500 }
1501
1502 if (ret_code == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1503 session->has_non_mmap_channel = true;
1504 }
1505 error:
1506 end:
1507 lttng_channel_destroy(attr);
1508 return ret_code;
1509 }
1510
1511 enum lttng_error_code
1512 cmd_process_attr_tracker_get_tracking_policy(struct ltt_session *session,
1513 enum lttng_domain_type domain,
1514 enum lttng_process_attr process_attr,
1515 enum lttng_tracking_policy *policy)
1516 {
1517 enum lttng_error_code ret_code = LTTNG_OK;
1518 const struct process_attr_tracker *tracker;
1519
1520 switch (domain) {
1521 case LTTNG_DOMAIN_KERNEL:
1522 if (!session->kernel_session) {
1523 ret_code = LTTNG_ERR_INVALID;
1524 goto end;
1525 }
1526 tracker = kernel_get_process_attr_tracker(session->kernel_session, process_attr);
1527 break;
1528 case LTTNG_DOMAIN_UST:
1529 if (!session->ust_session) {
1530 ret_code = LTTNG_ERR_INVALID;
1531 goto end;
1532 }
1533 tracker = trace_ust_get_process_attr_tracker(session->ust_session, process_attr);
1534 break;
1535 default:
1536 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1537 goto end;
1538 }
1539 if (tracker) {
1540 *policy = process_attr_tracker_get_tracking_policy(tracker);
1541 } else {
1542 ret_code = LTTNG_ERR_INVALID;
1543 }
1544 end:
1545 return ret_code;
1546 }
1547
1548 enum lttng_error_code
1549 cmd_process_attr_tracker_set_tracking_policy(struct ltt_session *session,
1550 enum lttng_domain_type domain,
1551 enum lttng_process_attr process_attr,
1552 enum lttng_tracking_policy policy)
1553 {
1554 enum lttng_error_code ret_code = LTTNG_OK;
1555
1556 switch (policy) {
1557 case LTTNG_TRACKING_POLICY_INCLUDE_SET:
1558 case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
1559 case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
1560 break;
1561 default:
1562 ret_code = LTTNG_ERR_INVALID;
1563 goto end;
1564 }
1565
1566 switch (domain) {
1567 case LTTNG_DOMAIN_KERNEL:
1568 if (!session->kernel_session) {
1569 ret_code = LTTNG_ERR_INVALID;
1570 goto end;
1571 }
1572 ret_code = kernel_process_attr_tracker_set_tracking_policy(
1573 session->kernel_session, process_attr, policy);
1574 break;
1575 case LTTNG_DOMAIN_UST:
1576 if (!session->ust_session) {
1577 ret_code = LTTNG_ERR_INVALID;
1578 goto end;
1579 }
1580 ret_code = trace_ust_process_attr_tracker_set_tracking_policy(
1581 session->ust_session, process_attr, policy);
1582 break;
1583 default:
1584 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1585 break;
1586 }
1587 end:
1588 return ret_code;
1589 }
1590
1591 enum lttng_error_code
1592 cmd_process_attr_tracker_inclusion_set_add_value(struct ltt_session *session,
1593 enum lttng_domain_type domain,
1594 enum lttng_process_attr process_attr,
1595 const struct process_attr_value *value)
1596 {
1597 enum lttng_error_code ret_code = LTTNG_OK;
1598
1599 switch (domain) {
1600 case LTTNG_DOMAIN_KERNEL:
1601 if (!session->kernel_session) {
1602 ret_code = LTTNG_ERR_INVALID;
1603 goto end;
1604 }
1605 ret_code = kernel_process_attr_tracker_inclusion_set_add_value(
1606 session->kernel_session, process_attr, value);
1607 break;
1608 case LTTNG_DOMAIN_UST:
1609 if (!session->ust_session) {
1610 ret_code = LTTNG_ERR_INVALID;
1611 goto end;
1612 }
1613 ret_code = trace_ust_process_attr_tracker_inclusion_set_add_value(
1614 session->ust_session, process_attr, value);
1615 break;
1616 default:
1617 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1618 break;
1619 }
1620 end:
1621 return ret_code;
1622 }
1623
1624 enum lttng_error_code
1625 cmd_process_attr_tracker_inclusion_set_remove_value(struct ltt_session *session,
1626 enum lttng_domain_type domain,
1627 enum lttng_process_attr process_attr,
1628 const struct process_attr_value *value)
1629 {
1630 enum lttng_error_code ret_code = LTTNG_OK;
1631
1632 switch (domain) {
1633 case LTTNG_DOMAIN_KERNEL:
1634 if (!session->kernel_session) {
1635 ret_code = LTTNG_ERR_INVALID;
1636 goto end;
1637 }
1638 ret_code = kernel_process_attr_tracker_inclusion_set_remove_value(
1639 session->kernel_session, process_attr, value);
1640 break;
1641 case LTTNG_DOMAIN_UST:
1642 if (!session->ust_session) {
1643 ret_code = LTTNG_ERR_INVALID;
1644 goto end;
1645 }
1646 ret_code = trace_ust_process_attr_tracker_inclusion_set_remove_value(
1647 session->ust_session, process_attr, value);
1648 break;
1649 default:
1650 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1651 break;
1652 }
1653 end:
1654 return ret_code;
1655 }
1656
1657 enum lttng_error_code
1658 cmd_process_attr_tracker_get_inclusion_set(struct ltt_session *session,
1659 enum lttng_domain_type domain,
1660 enum lttng_process_attr process_attr,
1661 struct lttng_process_attr_values **values)
1662 {
1663 enum lttng_error_code ret_code = LTTNG_OK;
1664 const struct process_attr_tracker *tracker;
1665 enum process_attr_tracker_status status;
1666
1667 switch (domain) {
1668 case LTTNG_DOMAIN_KERNEL:
1669 if (!session->kernel_session) {
1670 ret_code = LTTNG_ERR_INVALID;
1671 goto end;
1672 }
1673 tracker = kernel_get_process_attr_tracker(session->kernel_session, process_attr);
1674 break;
1675 case LTTNG_DOMAIN_UST:
1676 if (!session->ust_session) {
1677 ret_code = LTTNG_ERR_INVALID;
1678 goto end;
1679 }
1680 tracker = trace_ust_get_process_attr_tracker(session->ust_session, process_attr);
1681 break;
1682 default:
1683 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1684 goto end;
1685 }
1686
1687 if (!tracker) {
1688 ret_code = LTTNG_ERR_INVALID;
1689 goto end;
1690 }
1691
1692 status = process_attr_tracker_get_inclusion_set(tracker, values);
1693 switch (status) {
1694 case PROCESS_ATTR_TRACKER_STATUS_OK:
1695 ret_code = LTTNG_OK;
1696 break;
1697 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1698 ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1699 break;
1700 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1701 ret_code = LTTNG_ERR_NOMEM;
1702 break;
1703 default:
1704 ret_code = LTTNG_ERR_UNK;
1705 break;
1706 }
1707
1708 end:
1709 return ret_code;
1710 }
1711
1712 /*
1713 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1714 */
1715 int cmd_disable_event(struct command_ctx *cmd_ctx,
1716 struct lttng_event *event,
1717 char *filter_expression,
1718 struct lttng_bytecode *bytecode,
1719 struct lttng_event_exclusion *exclusion)
1720 {
1721 int ret;
1722 const char *event_name;
1723 const struct ltt_session *session = cmd_ctx->session;
1724 const char *channel_name = cmd_ctx->lsm.u.disable.channel_name;
1725 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1726
1727 DBG("Disable event command for event \'%s\'", event->name);
1728
1729 /*
1730 * Filter and exclusions are simply not handled by the
1731 * disable event command at this time.
1732 *
1733 * FIXME
1734 */
1735 (void) filter_expression;
1736 (void) exclusion;
1737
1738 /* Ignore the presence of filter or exclusion for the event */
1739 event->filter = 0;
1740 event->exclusion = 0;
1741
1742 event_name = event->name;
1743
1744 lttng::urcu::read_lock_guard read_lock;
1745
1746 /* Error out on unhandled search criteria */
1747 if (event->loglevel_type || event->loglevel != -1 || event->enabled || event->pid ||
1748 event->filter || event->exclusion) {
1749 ret = LTTNG_ERR_UNK;
1750 goto error;
1751 }
1752
1753 switch (domain) {
1754 case LTTNG_DOMAIN_KERNEL:
1755 {
1756 struct ltt_kernel_channel *kchan;
1757 struct ltt_kernel_session *ksess;
1758
1759 ksess = session->kernel_session;
1760
1761 /*
1762 * If a non-default channel has been created in the
1763 * session, explicitely require that -c chan_name needs
1764 * to be provided.
1765 */
1766 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1767 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1768 goto error_unlock;
1769 }
1770
1771 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1772 if (kchan == nullptr) {
1773 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1774 goto error_unlock;
1775 }
1776
1777 switch (event->type) {
1778 case LTTNG_EVENT_ALL:
1779 case LTTNG_EVENT_TRACEPOINT:
1780 case LTTNG_EVENT_SYSCALL:
1781 case LTTNG_EVENT_PROBE:
1782 case LTTNG_EVENT_FUNCTION:
1783 case LTTNG_EVENT_FUNCTION_ENTRY: /* fall-through */
1784 if (event_name[0] == '\0') {
1785 ret = event_kernel_disable_event(kchan, nullptr, event->type);
1786 } else {
1787 ret = event_kernel_disable_event(kchan, event_name, event->type);
1788 }
1789 if (ret != LTTNG_OK) {
1790 goto error_unlock;
1791 }
1792 break;
1793 default:
1794 ret = LTTNG_ERR_UNK;
1795 goto error_unlock;
1796 }
1797
1798 kernel_wait_quiescent();
1799 break;
1800 }
1801 case LTTNG_DOMAIN_UST:
1802 {
1803 struct ltt_ust_channel *uchan;
1804 struct ltt_ust_session *usess;
1805
1806 usess = session->ust_session;
1807
1808 if (validate_ust_event_name(event_name)) {
1809 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1810 goto error_unlock;
1811 }
1812
1813 /*
1814 * If a non-default channel has been created in the
1815 * session, explicitly require that -c chan_name needs
1816 * to be provided.
1817 */
1818 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1819 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1820 goto error_unlock;
1821 }
1822
1823 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, channel_name);
1824 if (uchan == nullptr) {
1825 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1826 goto error_unlock;
1827 }
1828
1829 switch (event->type) {
1830 case LTTNG_EVENT_ALL:
1831 /*
1832 * An empty event name means that everything
1833 * should be disabled.
1834 */
1835 if (event->name[0] == '\0') {
1836 ret = event_ust_disable_all_tracepoints(usess, uchan);
1837 } else {
1838 ret = event_ust_disable_tracepoint(usess, uchan, event_name);
1839 }
1840 if (ret != LTTNG_OK) {
1841 goto error_unlock;
1842 }
1843 break;
1844 default:
1845 ret = LTTNG_ERR_UNK;
1846 goto error_unlock;
1847 }
1848
1849 DBG3("Disable UST event %s in channel %s completed", event_name, channel_name);
1850 break;
1851 }
1852 case LTTNG_DOMAIN_LOG4J:
1853 case LTTNG_DOMAIN_JUL:
1854 case LTTNG_DOMAIN_PYTHON:
1855 {
1856 struct agent *agt;
1857 struct ltt_ust_session *usess = session->ust_session;
1858
1859 LTTNG_ASSERT(usess);
1860
1861 switch (event->type) {
1862 case LTTNG_EVENT_ALL:
1863 break;
1864 default:
1865 ret = LTTNG_ERR_UNK;
1866 goto error_unlock;
1867 }
1868
1869 agt = trace_ust_find_agent(usess, domain);
1870 if (!agt) {
1871 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1872 goto error_unlock;
1873 }
1874 /*
1875 * An empty event name means that everything
1876 * should be disabled.
1877 */
1878 if (event->name[0] == '\0') {
1879 ret = event_agent_disable_all(usess, agt);
1880 } else {
1881 ret = event_agent_disable(usess, agt, event_name);
1882 }
1883 if (ret != LTTNG_OK) {
1884 goto error_unlock;
1885 }
1886
1887 break;
1888 }
1889 default:
1890 ret = LTTNG_ERR_UND;
1891 goto error_unlock;
1892 }
1893
1894 ret = LTTNG_OK;
1895
1896 error_unlock:
1897 error:
1898 free(exclusion);
1899 free(bytecode);
1900 free(filter_expression);
1901 return ret;
1902 }
1903
1904 /*
1905 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1906 */
1907 int cmd_add_context(struct command_ctx *cmd_ctx,
1908 const struct lttng_event_context *event_context,
1909 int kwpipe)
1910 {
1911 int ret, chan_kern_created = 0, chan_ust_created = 0;
1912 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1913 const struct ltt_session *session = cmd_ctx->session;
1914 const char *channel_name = cmd_ctx->lsm.u.context.channel_name;
1915
1916 /*
1917 * Don't try to add a context if the session has been started at
1918 * some point in time before. The tracer does not allow it and would
1919 * result in a corrupted trace.
1920 */
1921 if (cmd_ctx->session->has_been_started) {
1922 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1923 goto end;
1924 }
1925
1926 switch (domain) {
1927 case LTTNG_DOMAIN_KERNEL:
1928 LTTNG_ASSERT(session->kernel_session);
1929
1930 if (session->kernel_session->channel_count == 0) {
1931 /* Create default channel */
1932 ret = channel_kernel_create(session->kernel_session, nullptr, kwpipe);
1933 if (ret != LTTNG_OK) {
1934 goto error;
1935 }
1936 chan_kern_created = 1;
1937 }
1938 /* Add kernel context to kernel tracer */
1939 ret = context_kernel_add(session->kernel_session, event_context, channel_name);
1940 if (ret != LTTNG_OK) {
1941 goto error;
1942 }
1943 break;
1944 case LTTNG_DOMAIN_JUL:
1945 case LTTNG_DOMAIN_LOG4J:
1946 {
1947 /*
1948 * Validate channel name.
1949 * If no channel name is given and the domain is JUL or LOG4J,
1950 * set it to the appropriate domain-specific channel name. If
1951 * a name is provided but does not match the expexted channel
1952 * name, return an error.
1953 */
1954 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1955 strcmp(channel_name, DEFAULT_JUL_CHANNEL_NAME) != 0) {
1956 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1957 goto error;
1958 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1959 strcmp(channel_name, DEFAULT_LOG4J_CHANNEL_NAME) != 0) {
1960 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1961 goto error;
1962 }
1963 }
1964 /* fall through */
1965 case LTTNG_DOMAIN_UST:
1966 {
1967 struct ltt_ust_session *usess = session->ust_session;
1968 unsigned int chan_count;
1969
1970 LTTNG_ASSERT(usess);
1971
1972 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1973 if (chan_count == 0) {
1974 struct lttng_channel *attr;
1975 /* Create default channel */
1976 attr = channel_new_default_attr(domain, usess->buffer_type);
1977 if (attr == nullptr) {
1978 ret = LTTNG_ERR_FATAL;
1979 goto error;
1980 }
1981
1982 ret = channel_ust_create(usess, attr, usess->buffer_type);
1983 if (ret != LTTNG_OK) {
1984 free(attr);
1985 goto error;
1986 }
1987 channel_attr_destroy(attr);
1988 chan_ust_created = 1;
1989 }
1990
1991 ret = context_ust_add(usess, domain, event_context, channel_name);
1992 if (ret != LTTNG_OK) {
1993 goto error;
1994 }
1995 break;
1996 }
1997 default:
1998 ret = LTTNG_ERR_UND;
1999 goto error;
2000 }
2001
2002 ret = LTTNG_OK;
2003 goto end;
2004
2005 error:
2006 if (chan_kern_created) {
2007 struct ltt_kernel_channel *kchan = trace_kernel_get_channel_by_name(
2008 DEFAULT_CHANNEL_NAME, session->kernel_session);
2009 /* Created previously, this should NOT fail. */
2010 LTTNG_ASSERT(kchan);
2011 kernel_destroy_channel(kchan);
2012 }
2013
2014 if (chan_ust_created) {
2015 struct ltt_ust_channel *uchan = trace_ust_find_channel_by_name(
2016 session->ust_session->domain_global.channels, DEFAULT_CHANNEL_NAME);
2017 /* Created previously, this should NOT fail. */
2018 LTTNG_ASSERT(uchan);
2019 /* Remove from the channel list of the session. */
2020 trace_ust_delete_channel(session->ust_session->domain_global.channels, uchan);
2021 trace_ust_destroy_channel(uchan);
2022 }
2023 end:
2024 return ret;
2025 }
2026
2027 static inline bool name_starts_with(const char *name, const char *prefix)
2028 {
2029 const size_t max_cmp_len = std::min(strlen(prefix), (size_t) LTTNG_SYMBOL_NAME_LEN);
2030
2031 return !strncmp(name, prefix, max_cmp_len);
2032 }
2033
2034 /* Perform userspace-specific event name validation */
2035 static int validate_ust_event_name(const char *name)
2036 {
2037 int ret = 0;
2038
2039 if (!name) {
2040 ret = -1;
2041 goto end;
2042 }
2043
2044 /*
2045 * Check name against all internal UST event component namespaces used
2046 * by the agents.
2047 */
2048 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2049 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2050 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2051 ret = -1;
2052 }
2053
2054 end:
2055 return ret;
2056 }
2057
2058 /*
2059 * Internal version of cmd_enable_event() with a supplemental
2060 * "internal_event" flag which is used to enable internal events which should
2061 * be hidden from clients. Such events are used in the agent implementation to
2062 * enable the events through which all "agent" events are funeled.
2063 */
2064 static int _cmd_enable_event(struct ltt_session *session,
2065 const struct lttng_domain *domain,
2066 char *channel_name,
2067 struct lttng_event *event,
2068 char *filter_expression,
2069 struct lttng_bytecode *filter,
2070 struct lttng_event_exclusion *exclusion,
2071 int wpipe,
2072 bool internal_event)
2073 {
2074 int ret = 0, channel_created = 0;
2075 struct lttng_channel *attr = nullptr;
2076
2077 LTTNG_ASSERT(session);
2078 LTTNG_ASSERT(event);
2079 LTTNG_ASSERT(channel_name);
2080
2081 /* If we have a filter, we must have its filter expression */
2082 LTTNG_ASSERT(!(!!filter_expression ^ !!filter));
2083
2084 /* Normalize event name as a globbing pattern */
2085 strutils_normalize_star_glob_pattern(event->name);
2086
2087 /* Normalize exclusion names as globbing patterns */
2088 if (exclusion) {
2089 size_t i;
2090
2091 for (i = 0; i < exclusion->count; i++) {
2092 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2093
2094 strutils_normalize_star_glob_pattern(name);
2095 }
2096 }
2097
2098 /* Normalize loglevel value to simplify comparisons. */
2099 if (event->loglevel_type == LTTNG_EVENT_LOGLEVEL_ALL) {
2100 /* Ignore the user-specified value; it has no meaning. */
2101 event->loglevel = -1;
2102 }
2103
2104 DBG("Enable event command for event \'%s\'", event->name);
2105
2106 lttng::urcu::read_lock_guard read_lock;
2107
2108 switch (domain->type) {
2109 case LTTNG_DOMAIN_KERNEL:
2110 {
2111 struct ltt_kernel_channel *kchan;
2112
2113 /*
2114 * If a non-default channel has been created in the
2115 * session, explicitely require that -c chan_name needs
2116 * to be provided.
2117 */
2118 if (session->kernel_session->has_non_default_channel && channel_name[0] == '\0') {
2119 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2120 goto error;
2121 }
2122
2123 kchan = trace_kernel_get_channel_by_name(channel_name, session->kernel_session);
2124 if (kchan == nullptr) {
2125 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL, LTTNG_BUFFER_GLOBAL);
2126 if (attr == nullptr) {
2127 ret = LTTNG_ERR_FATAL;
2128 goto error;
2129 }
2130 if (lttng_strncpy(attr->name, channel_name, sizeof(attr->name))) {
2131 ret = LTTNG_ERR_INVALID;
2132 goto error;
2133 }
2134
2135 ret = cmd_enable_channel_internal(session, domain, attr, wpipe);
2136 if (ret != LTTNG_OK) {
2137 goto error;
2138 }
2139 channel_created = 1;
2140 }
2141
2142 /* Get the newly created kernel channel pointer */
2143 kchan = trace_kernel_get_channel_by_name(channel_name, session->kernel_session);
2144 if (kchan == nullptr) {
2145 /* This sould not happen... */
2146 ret = LTTNG_ERR_FATAL;
2147 goto error;
2148 }
2149
2150 switch (event->type) {
2151 case LTTNG_EVENT_ALL:
2152 {
2153 char *filter_expression_a = nullptr;
2154 struct lttng_bytecode *filter_a = nullptr;
2155
2156 /*
2157 * We need to duplicate filter_expression and filter,
2158 * because ownership is passed to first enable
2159 * event.
2160 */
2161 if (filter_expression) {
2162 filter_expression_a = strdup(filter_expression);
2163 if (!filter_expression_a) {
2164 ret = LTTNG_ERR_FATAL;
2165 goto error;
2166 }
2167 }
2168 if (filter) {
2169 filter_a = zmalloc<lttng_bytecode>(sizeof(*filter_a) + filter->len);
2170 if (!filter_a) {
2171 free(filter_expression_a);
2172 ret = LTTNG_ERR_FATAL;
2173 goto error;
2174 }
2175 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2176 }
2177 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2178 ret = event_kernel_enable_event(kchan, event, filter_expression, filter);
2179 /* We have passed ownership */
2180 filter_expression = nullptr;
2181 filter = nullptr;
2182 if (ret != LTTNG_OK) {
2183 if (channel_created) {
2184 /* Let's not leak a useless channel. */
2185 kernel_destroy_channel(kchan);
2186 }
2187 free(filter_expression_a);
2188 free(filter_a);
2189 goto error;
2190 }
2191 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2192 ret = event_kernel_enable_event(
2193 kchan, event, filter_expression_a, filter_a);
2194 /* We have passed ownership */
2195 filter_expression_a = nullptr;
2196 filter_a = nullptr;
2197 if (ret != LTTNG_OK) {
2198 goto error;
2199 }
2200 break;
2201 }
2202 case LTTNG_EVENT_PROBE:
2203 case LTTNG_EVENT_USERSPACE_PROBE:
2204 case LTTNG_EVENT_FUNCTION:
2205 case LTTNG_EVENT_FUNCTION_ENTRY:
2206 case LTTNG_EVENT_TRACEPOINT:
2207 ret = event_kernel_enable_event(kchan, event, filter_expression, filter);
2208 /* We have passed ownership */
2209 filter_expression = nullptr;
2210 filter = nullptr;
2211 if (ret != LTTNG_OK) {
2212 if (channel_created) {
2213 /* Let's not leak a useless channel. */
2214 kernel_destroy_channel(kchan);
2215 }
2216 goto error;
2217 }
2218 break;
2219 case LTTNG_EVENT_SYSCALL:
2220 ret = event_kernel_enable_event(kchan, event, filter_expression, filter);
2221 /* We have passed ownership */
2222 filter_expression = nullptr;
2223 filter = nullptr;
2224 if (ret != LTTNG_OK) {
2225 goto error;
2226 }
2227 break;
2228 default:
2229 ret = LTTNG_ERR_UNK;
2230 goto error;
2231 }
2232
2233 kernel_wait_quiescent();
2234 break;
2235 }
2236 case LTTNG_DOMAIN_UST:
2237 {
2238 struct ltt_ust_channel *uchan;
2239 struct ltt_ust_session *usess = session->ust_session;
2240
2241 LTTNG_ASSERT(usess);
2242
2243 /*
2244 * If a non-default channel has been created in the
2245 * session, explicitely require that -c chan_name needs
2246 * to be provided.
2247 */
2248 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2249 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2250 goto error;
2251 }
2252
2253 /* Get channel from global UST domain */
2254 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels, channel_name);
2255 if (uchan == nullptr) {
2256 /* Create default channel */
2257 attr = channel_new_default_attr(LTTNG_DOMAIN_UST, usess->buffer_type);
2258 if (attr == nullptr) {
2259 ret = LTTNG_ERR_FATAL;
2260 goto error;
2261 }
2262 if (lttng_strncpy(attr->name, channel_name, sizeof(attr->name))) {
2263 ret = LTTNG_ERR_INVALID;
2264 goto error;
2265 }
2266
2267 ret = cmd_enable_channel_internal(session, domain, attr, wpipe);
2268 if (ret != LTTNG_OK) {
2269 goto error;
2270 }
2271
2272 /* Get the newly created channel reference back */
2273 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2274 channel_name);
2275 LTTNG_ASSERT(uchan);
2276 }
2277
2278 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2279 /*
2280 * Don't allow users to add UST events to channels which
2281 * are assigned to a userspace subdomain (JUL, Log4J,
2282 * Python, etc.).
2283 */
2284 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2285 goto error;
2286 }
2287
2288 if (!internal_event) {
2289 /*
2290 * Ensure the event name is not reserved for internal
2291 * use.
2292 */
2293 ret = validate_ust_event_name(event->name);
2294 if (ret) {
2295 WARN("Userspace event name %s failed validation.", event->name);
2296 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2297 goto error;
2298 }
2299 }
2300
2301 /* At this point, the session and channel exist on the tracer */
2302 ret = event_ust_enable_tracepoint(
2303 usess, uchan, event, filter_expression, filter, exclusion, internal_event);
2304 /* We have passed ownership */
2305 filter_expression = nullptr;
2306 filter = nullptr;
2307 exclusion = nullptr;
2308 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2309 goto already_enabled;
2310 } else if (ret != LTTNG_OK) {
2311 goto error;
2312 }
2313 break;
2314 }
2315 case LTTNG_DOMAIN_LOG4J:
2316 case LTTNG_DOMAIN_JUL:
2317 case LTTNG_DOMAIN_PYTHON:
2318 {
2319 const char *default_event_name, *default_chan_name;
2320 struct agent *agt;
2321 struct lttng_event uevent;
2322 struct lttng_domain tmp_dom;
2323 struct ltt_ust_session *usess = session->ust_session;
2324
2325 LTTNG_ASSERT(usess);
2326
2327 if (!agent_tracing_is_enabled()) {
2328 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2329 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2330 goto error;
2331 }
2332
2333 agt = trace_ust_find_agent(usess, domain->type);
2334 if (!agt) {
2335 agt = agent_create(domain->type);
2336 if (!agt) {
2337 ret = LTTNG_ERR_NOMEM;
2338 goto error;
2339 }
2340 agent_add(agt, usess->agents);
2341 }
2342
2343 /* Create the default tracepoint. */
2344 memset(&uevent, 0, sizeof(uevent));
2345 uevent.type = LTTNG_EVENT_TRACEPOINT;
2346 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2347 uevent.loglevel = -1;
2348 default_event_name = event_get_default_agent_ust_name(domain->type);
2349 if (!default_event_name) {
2350 ret = LTTNG_ERR_FATAL;
2351 goto error;
2352 }
2353 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2354 uevent.name[sizeof(uevent.name) - 1] = '\0';
2355
2356 /*
2357 * The domain type is changed because we are about to enable the
2358 * default channel and event for the JUL domain that are hardcoded.
2359 * This happens in the UST domain.
2360 */
2361 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2362 tmp_dom.type = LTTNG_DOMAIN_UST;
2363
2364 switch (domain->type) {
2365 case LTTNG_DOMAIN_LOG4J:
2366 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2367 break;
2368 case LTTNG_DOMAIN_JUL:
2369 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2370 break;
2371 case LTTNG_DOMAIN_PYTHON:
2372 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2373 break;
2374 default:
2375 /* The switch/case we are in makes this impossible */
2376 abort();
2377 }
2378
2379 {
2380 char *filter_expression_copy = nullptr;
2381 struct lttng_bytecode *filter_copy = nullptr;
2382
2383 if (filter) {
2384 const size_t filter_size =
2385 sizeof(struct lttng_bytecode) + filter->len;
2386
2387 filter_copy = zmalloc<lttng_bytecode>(filter_size);
2388 if (!filter_copy) {
2389 ret = LTTNG_ERR_NOMEM;
2390 goto error;
2391 }
2392 memcpy(filter_copy, filter, filter_size);
2393
2394 filter_expression_copy = strdup(filter_expression);
2395 if (!filter_expression) {
2396 ret = LTTNG_ERR_NOMEM;
2397 }
2398
2399 if (!filter_expression_copy || !filter_copy) {
2400 free(filter_expression_copy);
2401 free(filter_copy);
2402 goto error;
2403 }
2404 }
2405
2406 ret = cmd_enable_event_internal(session,
2407 &tmp_dom,
2408 (char *) default_chan_name,
2409 &uevent,
2410 filter_expression_copy,
2411 filter_copy,
2412 nullptr,
2413 wpipe);
2414 }
2415
2416 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2417 goto already_enabled;
2418 } else if (ret != LTTNG_OK) {
2419 goto error;
2420 }
2421
2422 /* The wild card * means that everything should be enabled. */
2423 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2424 ret = event_agent_enable_all(usess, agt, event, filter, filter_expression);
2425 } else {
2426 ret = event_agent_enable(usess, agt, event, filter, filter_expression);
2427 }
2428 filter = nullptr;
2429 filter_expression = nullptr;
2430 if (ret != LTTNG_OK) {
2431 goto error;
2432 }
2433
2434 break;
2435 }
2436 default:
2437 ret = LTTNG_ERR_UND;
2438 goto error;
2439 }
2440
2441 ret = LTTNG_OK;
2442
2443 already_enabled:
2444 error:
2445 free(filter_expression);
2446 free(filter);
2447 free(exclusion);
2448 channel_attr_destroy(attr);
2449 return ret;
2450 }
2451
2452 /*
2453 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2454 * We own filter, exclusion, and filter_expression.
2455 */
2456 int cmd_enable_event(struct command_ctx *cmd_ctx,
2457 struct lttng_event *event,
2458 char *filter_expression,
2459 struct lttng_event_exclusion *exclusion,
2460 struct lttng_bytecode *bytecode,
2461 int wpipe)
2462 {
2463 int ret;
2464 /*
2465 * Copied to ensure proper alignment since 'lsm' is a packed structure.
2466 */
2467 const lttng_domain command_domain = cmd_ctx->lsm.domain;
2468
2469 /*
2470 * The ownership of the following parameters is transferred to
2471 * _cmd_enable_event:
2472 *
2473 * - filter_expression,
2474 * - bytecode,
2475 * - exclusion
2476 */
2477 ret = _cmd_enable_event(cmd_ctx->session,
2478 &command_domain,
2479 cmd_ctx->lsm.u.enable.channel_name,
2480 event,
2481 filter_expression,
2482 bytecode,
2483 exclusion,
2484 wpipe,
2485 false);
2486 filter_expression = nullptr;
2487 bytecode = nullptr;
2488 exclusion = nullptr;
2489 return ret;
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,
2500 struct lttng_event *event,
2501 char *filter_expression,
2502 struct lttng_bytecode *filter,
2503 struct lttng_event_exclusion *exclusion,
2504 int wpipe)
2505 {
2506 return _cmd_enable_event(session,
2507 domain,
2508 channel_name,
2509 event,
2510 filter_expression,
2511 filter,
2512 exclusion,
2513 wpipe,
2514 true);
2515 }
2516
2517 /*
2518 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2519 */
2520 enum lttng_error_code cmd_list_tracepoints(enum lttng_domain_type domain,
2521 struct lttng_payload *reply_payload)
2522 {
2523 enum lttng_error_code ret_code;
2524 int ret;
2525 ssize_t i, nb_events = 0;
2526 struct lttng_event *events = nullptr;
2527 struct lttcomm_list_command_header reply_command_header = {};
2528 size_t reply_command_header_offset;
2529
2530 assert(reply_payload);
2531
2532 /* Reserve space for command reply header. */
2533 reply_command_header_offset = reply_payload->buffer.size;
2534 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2535 reply_command_header_offset +
2536 sizeof(struct lttcomm_list_command_header));
2537 if (ret) {
2538 ret_code = LTTNG_ERR_NOMEM;
2539 goto error;
2540 }
2541
2542 switch (domain) {
2543 case LTTNG_DOMAIN_KERNEL:
2544 nb_events = kernel_list_events(&events);
2545 if (nb_events < 0) {
2546 ret_code = LTTNG_ERR_KERN_LIST_FAIL;
2547 goto error;
2548 }
2549 break;
2550 case LTTNG_DOMAIN_UST:
2551 nb_events = ust_app_list_events(&events);
2552 if (nb_events < 0) {
2553 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2554 goto error;
2555 }
2556 break;
2557 case LTTNG_DOMAIN_LOG4J:
2558 case LTTNG_DOMAIN_JUL:
2559 case LTTNG_DOMAIN_PYTHON:
2560 nb_events = agent_list_events(&events, domain);
2561 if (nb_events < 0) {
2562 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2563 goto error;
2564 }
2565 break;
2566 default:
2567 ret_code = LTTNG_ERR_UND;
2568 goto error;
2569 }
2570
2571 for (i = 0; i < nb_events; i++) {
2572 ret = lttng_event_serialize(
2573 &events[i], 0, nullptr, nullptr, 0, nullptr, reply_payload);
2574 if (ret) {
2575 ret_code = LTTNG_ERR_NOMEM;
2576 goto error;
2577 }
2578 }
2579
2580 if (nb_events > UINT32_MAX) {
2581 ERR("Tracepoint count would overflow the tracepoint listing command's reply");
2582 ret_code = LTTNG_ERR_OVERFLOW;
2583 goto error;
2584 }
2585
2586 /* Update command reply header. */
2587 reply_command_header.count = (uint32_t) nb_events;
2588 memcpy(reply_payload->buffer.data + reply_command_header_offset,
2589 &reply_command_header,
2590 sizeof(reply_command_header));
2591
2592 ret_code = LTTNG_OK;
2593 error:
2594 free(events);
2595 return ret_code;
2596 }
2597
2598 /*
2599 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2600 */
2601 enum lttng_error_code cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2602 struct lttng_payload *reply)
2603 {
2604 enum lttng_error_code ret_code;
2605 int ret;
2606 unsigned int i, nb_fields;
2607 struct lttng_event_field *fields = nullptr;
2608 struct lttcomm_list_command_header reply_command_header = {};
2609 size_t reply_command_header_offset;
2610
2611 assert(reply);
2612
2613 /* Reserve space for command reply header. */
2614 reply_command_header_offset = reply->buffer.size;
2615 ret = lttng_dynamic_buffer_set_size(&reply->buffer,
2616 reply_command_header_offset +
2617 sizeof(struct lttcomm_list_command_header));
2618 if (ret) {
2619 ret_code = LTTNG_ERR_NOMEM;
2620 goto error;
2621 }
2622
2623 switch (domain) {
2624 case LTTNG_DOMAIN_UST:
2625 ret = ust_app_list_event_fields(&fields);
2626 if (ret < 0) {
2627 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2628 goto error;
2629 }
2630
2631 break;
2632 case LTTNG_DOMAIN_KERNEL:
2633 default: /* fall-through */
2634 ret_code = LTTNG_ERR_UND;
2635 goto error;
2636 }
2637
2638 nb_fields = ret;
2639
2640 for (i = 0; i < nb_fields; i++) {
2641 ret = lttng_event_field_serialize(&fields[i], reply);
2642 if (ret) {
2643 ret_code = LTTNG_ERR_NOMEM;
2644 goto error;
2645 }
2646 }
2647
2648 if (nb_fields > UINT32_MAX) {
2649 ERR("Tracepoint field count would overflow the tracepoint field listing command's reply");
2650 ret_code = LTTNG_ERR_OVERFLOW;
2651 goto error;
2652 }
2653
2654 /* Update command reply header. */
2655 reply_command_header.count = (uint32_t) nb_fields;
2656
2657 memcpy(reply->buffer.data + reply_command_header_offset,
2658 &reply_command_header,
2659 sizeof(reply_command_header));
2660
2661 ret_code = LTTNG_OK;
2662
2663 error:
2664 free(fields);
2665 return ret_code;
2666 }
2667
2668 enum lttng_error_code cmd_list_syscalls(struct lttng_payload *reply_payload)
2669 {
2670 enum lttng_error_code ret_code;
2671 ssize_t nb_events, i;
2672 int ret;
2673 struct lttng_event *events = nullptr;
2674 struct lttcomm_list_command_header reply_command_header = {};
2675 size_t reply_command_header_offset;
2676
2677 assert(reply_payload);
2678
2679 /* Reserve space for command reply header. */
2680 reply_command_header_offset = reply_payload->buffer.size;
2681 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2682 reply_command_header_offset +
2683 sizeof(struct lttcomm_list_command_header));
2684 if (ret) {
2685 ret_code = LTTNG_ERR_NOMEM;
2686 goto end;
2687 }
2688
2689 nb_events = syscall_table_list(&events);
2690 if (nb_events < 0) {
2691 ret_code = (enum lttng_error_code) - nb_events;
2692 goto end;
2693 }
2694
2695 for (i = 0; i < nb_events; i++) {
2696 ret = lttng_event_serialize(
2697 &events[i], 0, nullptr, nullptr, 0, nullptr, reply_payload);
2698 if (ret) {
2699 ret_code = LTTNG_ERR_NOMEM;
2700 goto end;
2701 }
2702 }
2703
2704 if (nb_events > UINT32_MAX) {
2705 ERR("Syscall count would overflow the syscall listing command's reply");
2706 ret_code = LTTNG_ERR_OVERFLOW;
2707 goto end;
2708 }
2709
2710 /* Update command reply header. */
2711 reply_command_header.count = (uint32_t) nb_events;
2712 memcpy(reply_payload->buffer.data + reply_command_header_offset,
2713 &reply_command_header,
2714 sizeof(reply_command_header));
2715
2716 ret_code = LTTNG_OK;
2717 end:
2718 free(events);
2719 return ret_code;
2720 }
2721
2722 /*
2723 * Command LTTNG_START_TRACE processed by the client thread.
2724 *
2725 * Called with session mutex held.
2726 */
2727 int cmd_start_trace(struct ltt_session *session)
2728 {
2729 enum lttng_error_code ret;
2730 unsigned long nb_chan = 0;
2731 struct ltt_kernel_session *ksession;
2732 struct ltt_ust_session *usess;
2733 const bool session_rotated_after_last_stop = session->rotated_after_last_stop;
2734 const bool session_cleared_after_last_stop = session->cleared_after_last_stop;
2735
2736 LTTNG_ASSERT(session);
2737
2738 /* Ease our life a bit ;) */
2739 ksession = session->kernel_session;
2740 usess = session->ust_session;
2741
2742 /* Is the session already started? */
2743 if (session->active) {
2744 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2745 /* Perform nothing */
2746 goto end;
2747 }
2748
2749 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2750 !session->current_trace_chunk) {
2751 /*
2752 * A rotation was launched while the session was stopped and
2753 * it has not been completed yet. It is not possible to start
2754 * the session since starting the session here would require a
2755 * rotation from "NULL" to a new trace chunk. That rotation
2756 * would overlap with the ongoing rotation, which is not
2757 * supported.
2758 */
2759 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2760 session->name);
2761 ret = LTTNG_ERR_ROTATION_PENDING;
2762 goto error;
2763 }
2764
2765 /*
2766 * Starting a session without channel is useless since after that it's not
2767 * possible to enable channel thus inform the client.
2768 */
2769 if (usess && usess->domain_global.channels) {
2770 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2771 }
2772 if (ksession) {
2773 nb_chan += ksession->channel_count;
2774 }
2775 if (!nb_chan) {
2776 ret = LTTNG_ERR_NO_CHANNEL;
2777 goto error;
2778 }
2779
2780 session->active = true;
2781 session->rotated_after_last_stop = false;
2782 session->cleared_after_last_stop = false;
2783 if (session->output_traces && !session->current_trace_chunk) {
2784 if (!session->has_been_started) {
2785 struct lttng_trace_chunk *trace_chunk;
2786
2787 DBG("Creating initial trace chunk of session \"%s\"", session->name);
2788 trace_chunk =
2789 session_create_new_trace_chunk(session, nullptr, nullptr, nullptr);
2790 if (!trace_chunk) {
2791 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2792 goto error;
2793 }
2794 LTTNG_ASSERT(!session->current_trace_chunk);
2795 ret = (lttng_error_code) session_set_trace_chunk(
2796 session, trace_chunk, nullptr);
2797 lttng_trace_chunk_put(trace_chunk);
2798 if (ret) {
2799 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2800 goto error;
2801 }
2802 } else {
2803 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2804 session->name);
2805 /*
2806 * Rotate existing streams into the new chunk.
2807 * This is a "quiet" rotation has no client has
2808 * explicitly requested this operation.
2809 *
2810 * There is also no need to wait for the rotation
2811 * to complete as it will happen immediately. No data
2812 * was produced as the session was stopped, so the
2813 * rotation should happen on reception of the command.
2814 */
2815 ret = (lttng_error_code) cmd_rotate_session(
2816 session, nullptr, true, LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2817 if (ret != LTTNG_OK) {
2818 goto error;
2819 }
2820 }
2821 }
2822
2823 /* Kernel tracing */
2824 if (ksession != nullptr) {
2825 DBG("Start kernel tracing session %s", session->name);
2826 ret = (lttng_error_code) start_kernel_session(ksession);
2827 if (ret != LTTNG_OK) {
2828 goto error;
2829 }
2830 }
2831
2832 /* Flag session that trace should start automatically */
2833 if (usess) {
2834 int int_ret = ust_app_start_trace_all(usess);
2835
2836 if (int_ret < 0) {
2837 ret = LTTNG_ERR_UST_START_FAIL;
2838 goto error;
2839 }
2840 }
2841
2842 /*
2843 * Open a packet in every stream of the session to ensure that viewers
2844 * can correctly identify the boundaries of the periods during which
2845 * tracing was active for this session.
2846 */
2847 ret = session_open_packets(session);
2848 if (ret != LTTNG_OK) {
2849 goto error;
2850 }
2851
2852 /*
2853 * Clear the flag that indicates that a rotation was done while the
2854 * session was stopped.
2855 */
2856 session->rotated_after_last_stop = false;
2857
2858 if (session->rotate_timer_period && !session->rotation_schedule_timer_enabled) {
2859 int int_ret = timer_session_rotation_schedule_timer_start(
2860 session, session->rotate_timer_period);
2861
2862 if (int_ret < 0) {
2863 ERR("Failed to enable rotate timer");
2864 ret = LTTNG_ERR_UNK;
2865 goto error;
2866 }
2867 }
2868
2869 ret = LTTNG_OK;
2870
2871 error:
2872 if (ret == LTTNG_OK) {
2873 /* Flag this after a successful start. */
2874 session->has_been_started = true;
2875 } else {
2876 session->active = false;
2877 /* Restore initial state on error. */
2878 session->rotated_after_last_stop = session_rotated_after_last_stop;
2879 session->cleared_after_last_stop = session_cleared_after_last_stop;
2880 }
2881 end:
2882 return ret;
2883 }
2884
2885 /*
2886 * Command LTTNG_STOP_TRACE processed by the client thread.
2887 */
2888 int cmd_stop_trace(struct ltt_session *session)
2889 {
2890 int ret;
2891 struct ltt_kernel_session *ksession;
2892 struct ltt_ust_session *usess;
2893
2894 LTTNG_ASSERT(session);
2895
2896 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2897 /* Short cut */
2898 ksession = session->kernel_session;
2899 usess = session->ust_session;
2900
2901 /* Session is not active. Skip everything and inform the client. */
2902 if (!session->active) {
2903 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2904 goto error;
2905 }
2906
2907 ret = stop_kernel_session(ksession);
2908 if (ret != LTTNG_OK) {
2909 goto error;
2910 }
2911
2912 if (usess && usess->active) {
2913 ret = ust_app_stop_trace_all(usess);
2914 if (ret < 0) {
2915 ret = LTTNG_ERR_UST_STOP_FAIL;
2916 goto error;
2917 }
2918 }
2919
2920 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2921 /* Flag inactive after a successful stop. */
2922 session->active = false;
2923 ret = LTTNG_OK;
2924
2925 error:
2926 return ret;
2927 }
2928
2929 /*
2930 * Set the base_path of the session only if subdir of a control uris is set.
2931 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2932 */
2933 static int
2934 set_session_base_path_from_uris(struct ltt_session *session, size_t nb_uri, struct lttng_uri *uris)
2935 {
2936 int ret;
2937 size_t i;
2938
2939 for (i = 0; i < nb_uri; i++) {
2940 if (uris[i].stype != LTTNG_STREAM_CONTROL || uris[i].subdir[0] == '\0') {
2941 /* Not interested in these URIs */
2942 continue;
2943 }
2944
2945 if (session->base_path != nullptr) {
2946 free(session->base_path);
2947 session->base_path = nullptr;
2948 }
2949
2950 /* Set session base_path */
2951 session->base_path = strdup(uris[i].subdir);
2952 if (!session->base_path) {
2953 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2954 uris[i].subdir,
2955 session->name);
2956 ret = LTTNG_ERR_NOMEM;
2957 goto error;
2958 }
2959 DBG2("Setting base path \"%s\" for session \"%s\"",
2960 session->base_path,
2961 session->name);
2962 }
2963 ret = LTTNG_OK;
2964 error:
2965 return ret;
2966 }
2967
2968 /*
2969 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2970 */
2971 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri, struct lttng_uri *uris)
2972 {
2973 int ret, i;
2974 struct ltt_kernel_session *ksess = session->kernel_session;
2975 struct ltt_ust_session *usess = session->ust_session;
2976
2977 LTTNG_ASSERT(session);
2978 LTTNG_ASSERT(uris);
2979 LTTNG_ASSERT(nb_uri > 0);
2980
2981 /* Can't set consumer URI if the session is active. */
2982 if (session->active) {
2983 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2984 goto error;
2985 }
2986
2987 /*
2988 * Set the session base path if any. This is done inside
2989 * cmd_set_consumer_uri to preserve backward compatibility of the
2990 * previous session creation api vs the session descriptor api.
2991 */
2992 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2993 if (ret != LTTNG_OK) {
2994 goto error;
2995 }
2996
2997 /* Set the "global" consumer URIs */
2998 for (i = 0; i < nb_uri; i++) {
2999 ret = add_uri_to_consumer(session, session->consumer, &uris[i], LTTNG_DOMAIN_NONE);
3000 if (ret != LTTNG_OK) {
3001 goto error;
3002 }
3003 }
3004
3005 /* Set UST session URIs */
3006 if (session->ust_session) {
3007 for (i = 0; i < nb_uri; i++) {
3008 ret = add_uri_to_consumer(session,
3009 session->ust_session->consumer,
3010 &uris[i],
3011 LTTNG_DOMAIN_UST);
3012 if (ret != LTTNG_OK) {
3013 goto error;
3014 }
3015 }
3016 }
3017
3018 /* Set kernel session URIs */
3019 if (session->kernel_session) {
3020 for (i = 0; i < nb_uri; i++) {
3021 ret = add_uri_to_consumer(session,
3022 session->kernel_session->consumer,
3023 &uris[i],
3024 LTTNG_DOMAIN_KERNEL);
3025 if (ret != LTTNG_OK) {
3026 goto error;
3027 }
3028 }
3029 }
3030
3031 /*
3032 * Make sure to set the session in output mode after we set URI since a
3033 * session can be created without URL (thus flagged in no output mode).
3034 */
3035 session->output_traces = 1;
3036 if (ksess) {
3037 ksess->output_traces = 1;
3038 }
3039
3040 if (usess) {
3041 usess->output_traces = 1;
3042 }
3043
3044 /* All good! */
3045 ret = LTTNG_OK;
3046
3047 error:
3048 return ret;
3049 }
3050
3051 static enum lttng_error_code
3052 set_session_output_from_descriptor(struct ltt_session *session,
3053 const struct lttng_session_descriptor *descriptor)
3054 {
3055 int ret;
3056 enum lttng_error_code ret_code = LTTNG_OK;
3057 enum lttng_session_descriptor_type session_type =
3058 lttng_session_descriptor_get_type(descriptor);
3059 enum lttng_session_descriptor_output_type output_type =
3060 lttng_session_descriptor_get_output_type(descriptor);
3061 struct lttng_uri uris[2] = {};
3062 size_t uri_count = 0;
3063
3064 switch (output_type) {
3065 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
3066 goto end;
3067 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
3068 lttng_session_descriptor_get_local_output_uri(descriptor, &uris[0]);
3069 uri_count = 1;
3070 break;
3071 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
3072 lttng_session_descriptor_get_network_output_uris(descriptor, &uris[0], &uris[1]);
3073 uri_count = 2;
3074 break;
3075 default:
3076 ret_code = LTTNG_ERR_INVALID;
3077 goto end;
3078 }
3079
3080 switch (session_type) {
3081 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3082 {
3083 struct snapshot_output *new_output = nullptr;
3084
3085 new_output = snapshot_output_alloc();
3086 if (!new_output) {
3087 ret_code = LTTNG_ERR_NOMEM;
3088 goto end;
3089 }
3090
3091 ret = snapshot_output_init_with_uri(session,
3092 DEFAULT_SNAPSHOT_MAX_SIZE,
3093 nullptr,
3094 uris,
3095 uri_count,
3096 session->consumer,
3097 new_output,
3098 &session->snapshot);
3099 if (ret < 0) {
3100 ret_code = (ret == -ENOMEM) ? LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
3101 snapshot_output_destroy(new_output);
3102 goto end;
3103 }
3104 snapshot_add_output(&session->snapshot, new_output);
3105 break;
3106 }
3107 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3108 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3109 {
3110 ret_code = (lttng_error_code) cmd_set_consumer_uri(session, uri_count, uris);
3111 break;
3112 }
3113 default:
3114 ret_code = LTTNG_ERR_INVALID;
3115 goto end;
3116 }
3117 end:
3118 return ret_code;
3119 }
3120
3121 static enum lttng_error_code
3122 cmd_create_session_from_descriptor(struct lttng_session_descriptor *descriptor,
3123 const lttng_sock_cred *creds,
3124 const char *home_path)
3125 {
3126 int ret;
3127 enum lttng_error_code ret_code;
3128 const char *session_name;
3129 struct ltt_session *new_session = nullptr;
3130 enum lttng_session_descriptor_status descriptor_status;
3131
3132 session_lock_list();
3133 if (home_path) {
3134 if (*home_path != '/') {
3135 ERR("Home path provided by client is not absolute");
3136 ret_code = LTTNG_ERR_INVALID;
3137 goto end;
3138 }
3139 }
3140
3141 descriptor_status = lttng_session_descriptor_get_session_name(descriptor, &session_name);
3142 switch (descriptor_status) {
3143 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3144 break;
3145 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3146 session_name = nullptr;
3147 break;
3148 default:
3149 ret_code = LTTNG_ERR_INVALID;
3150 goto end;
3151 }
3152
3153 ret_code = session_create(session_name, creds->uid, creds->gid, &new_session);
3154 if (ret_code != LTTNG_OK) {
3155 goto end;
3156 }
3157
3158 ret_code = notification_thread_command_add_session(the_notification_thread_handle,
3159 new_session->id,
3160 new_session->name,
3161 new_session->uid,
3162 new_session->gid);
3163 if (ret_code != LTTNG_OK) {
3164 goto end;
3165 }
3166
3167 /* Announce the session's destruction to the notification thread when it is destroyed. */
3168 ret = session_add_destroy_notifier(
3169 new_session,
3170 [](const struct ltt_session *session, void *user_data __attribute__((unused))) {
3171 (void) notification_thread_command_remove_session(
3172 the_notification_thread_handle, session->id);
3173 },
3174 nullptr);
3175 if (ret) {
3176 PERROR("Failed to add notification thread command to session's destroy notifiers: session name = %s",
3177 new_session->name);
3178 ret = LTTNG_ERR_NOMEM;
3179 goto end;
3180 }
3181
3182 if (!session_name) {
3183 ret = lttng_session_descriptor_set_session_name(descriptor, new_session->name);
3184 if (ret) {
3185 ret_code = LTTNG_ERR_SESSION_FAIL;
3186 goto end;
3187 }
3188 }
3189
3190 if (!lttng_session_descriptor_is_output_destination_initialized(descriptor)) {
3191 /*
3192 * Only include the session's creation time in the output
3193 * destination if the name of the session itself was
3194 * not auto-generated.
3195 */
3196 ret_code = lttng_session_descriptor_set_default_output(
3197 descriptor,
3198 session_name ? &new_session->creation_time : nullptr,
3199 home_path);
3200 if (ret_code != LTTNG_OK) {
3201 goto end;
3202 }
3203 } else {
3204 new_session->has_user_specified_directory =
3205 lttng_session_descriptor_has_output_directory(descriptor);
3206 }
3207
3208 switch (lttng_session_descriptor_get_type(descriptor)) {
3209 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3210 new_session->snapshot_mode = 1;
3211 break;
3212 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3213 new_session->live_timer =
3214 lttng_session_descriptor_live_get_timer_interval(descriptor);
3215 break;
3216 default:
3217 break;
3218 }
3219
3220 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3221 if (ret_code != LTTNG_OK) {
3222 goto end;
3223 }
3224 new_session->consumer->enabled = true;
3225 ret_code = LTTNG_OK;
3226 end:
3227 /* Release reference provided by the session_create function. */
3228 session_put(new_session);
3229 if (ret_code != LTTNG_OK && new_session) {
3230 /* Release the global reference on error. */
3231 session_destroy(new_session);
3232 }
3233 session_unlock_list();
3234 return ret_code;
3235 }
3236
3237 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx,
3238 int sock,
3239 struct lttng_session_descriptor **return_descriptor)
3240 {
3241 int ret;
3242 size_t payload_size;
3243 struct lttng_dynamic_buffer payload;
3244 struct lttng_buffer_view home_dir_view;
3245 struct lttng_buffer_view session_descriptor_view;
3246 struct lttng_session_descriptor *session_descriptor = nullptr;
3247 enum lttng_error_code ret_code;
3248
3249 lttng_dynamic_buffer_init(&payload);
3250 if (cmd_ctx->lsm.u.create_session.home_dir_size >= LTTNG_PATH_MAX) {
3251 ret_code = LTTNG_ERR_INVALID;
3252 goto error;
3253 }
3254 if (cmd_ctx->lsm.u.create_session.session_descriptor_size >
3255 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3256 ret_code = LTTNG_ERR_INVALID;
3257 goto error;
3258 }
3259
3260 payload_size = cmd_ctx->lsm.u.create_session.home_dir_size +
3261 cmd_ctx->lsm.u.create_session.session_descriptor_size;
3262 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3263 if (ret) {
3264 ret_code = LTTNG_ERR_NOMEM;
3265 goto error;
3266 }
3267
3268 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3269 if (ret <= 0) {
3270 ERR("Reception of session descriptor failed, aborting.");
3271 ret_code = LTTNG_ERR_SESSION_FAIL;
3272 goto error;
3273 }
3274
3275 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3276 &payload, 0, cmd_ctx->lsm.u.create_session.home_dir_size);
3277 if (cmd_ctx->lsm.u.create_session.home_dir_size > 0 &&
3278 !lttng_buffer_view_is_valid(&home_dir_view)) {
3279 ERR("Invalid payload in \"create session\" command: buffer too short to contain home directory");
3280 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3281 goto error;
3282 }
3283
3284 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3285 &payload,
3286 cmd_ctx->lsm.u.create_session.home_dir_size,
3287 cmd_ctx->lsm.u.create_session.session_descriptor_size);
3288 if (!lttng_buffer_view_is_valid(&session_descriptor_view)) {
3289 ERR("Invalid payload in \"create session\" command: buffer too short to contain session descriptor");
3290 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3291 goto error;
3292 }
3293
3294 ret = lttng_session_descriptor_create_from_buffer(&session_descriptor_view,
3295 &session_descriptor);
3296 if (ret < 0) {
3297 ERR("Failed to create session descriptor from payload of \"create session\" command");
3298 ret_code = LTTNG_ERR_INVALID;
3299 goto error;
3300 }
3301
3302 /*
3303 * Sets the descriptor's auto-generated properties (name, output) if
3304 * needed.
3305 */
3306 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3307 &cmd_ctx->creds,
3308 home_dir_view.size ? home_dir_view.data :
3309 nullptr);
3310 if (ret_code != LTTNG_OK) {
3311 goto error;
3312 }
3313
3314 ret_code = LTTNG_OK;
3315 *return_descriptor = session_descriptor;
3316 session_descriptor = nullptr;
3317 error:
3318 lttng_dynamic_buffer_reset(&payload);
3319 lttng_session_descriptor_destroy(session_descriptor);
3320 return ret_code;
3321 }
3322
3323 static void cmd_destroy_session_reply(const struct ltt_session *session, void *_reply_context)
3324 {
3325 int ret;
3326 ssize_t comm_ret;
3327 const struct cmd_destroy_session_reply_context *reply_context =
3328 (cmd_destroy_session_reply_context *) _reply_context;
3329 struct lttng_dynamic_buffer payload;
3330 struct lttcomm_session_destroy_command_header cmd_header;
3331 struct lttng_trace_archive_location *location = nullptr;
3332 struct lttcomm_lttng_msg llm = {
3333 .cmd_type = LTTCOMM_SESSIOND_COMMAND_DESTROY_SESSION,
3334 .ret_code = reply_context->destruction_status,
3335 .pid = UINT32_MAX,
3336 .cmd_header_size = sizeof(struct lttcomm_session_destroy_command_header),
3337 .data_size = 0,
3338 .fd_count = 0,
3339 };
3340 size_t payload_size_before_location;
3341
3342 lttng_dynamic_buffer_init(&payload);
3343
3344 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3345 if (ret) {
3346 ERR("Failed to append session destruction message");
3347 goto error;
3348 }
3349
3350 cmd_header.rotation_state = (int32_t) (reply_context->implicit_rotation_on_destroy ?
3351 session->rotation_state :
3352 LTTNG_ROTATION_STATE_NO_ROTATION);
3353 ret = lttng_dynamic_buffer_append(&payload, &cmd_header, sizeof(cmd_header));
3354 if (ret) {
3355 ERR("Failed to append session destruction command header");
3356 goto error;
3357 }
3358
3359 if (!reply_context->implicit_rotation_on_destroy) {
3360 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3361 session->name);
3362 goto send_reply;
3363 }
3364 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3365 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3366 session->name);
3367 goto send_reply;
3368 }
3369
3370 location = session_get_trace_archive_location(session);
3371 if (!location) {
3372 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3373 session->name);
3374 goto error;
3375 }
3376
3377 payload_size_before_location = payload.size;
3378 comm_ret = lttng_trace_archive_location_serialize(location, &payload);
3379 lttng_trace_archive_location_put(location);
3380 if (comm_ret < 0) {
3381 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3382 session->name);
3383 goto error;
3384 }
3385 /* Update the message to indicate the location's length. */
3386 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3387 payload.size - payload_size_before_location;
3388 send_reply:
3389 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd, payload.data, payload.size);
3390 if (comm_ret != (ssize_t) payload.size) {
3391 ERR("Failed to send result of the destruction of session \"%s\" to client",
3392 session->name);
3393 }
3394 error:
3395 ret = close(reply_context->reply_sock_fd);
3396 if (ret) {
3397 PERROR("Failed to close client socket in deferred session destroy reply");
3398 }
3399 lttng_dynamic_buffer_reset(&payload);
3400 free(_reply_context);
3401 }
3402
3403 /*
3404 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3405 *
3406 * Called with session lock held.
3407 */
3408 int cmd_destroy_session(struct ltt_session *session, int *sock_fd)
3409 {
3410 int ret;
3411 enum lttng_error_code destruction_last_error = LTTNG_OK;
3412 struct cmd_destroy_session_reply_context *reply_context = nullptr;
3413
3414 if (sock_fd) {
3415 reply_context = zmalloc<cmd_destroy_session_reply_context>();
3416 if (!reply_context) {
3417 ret = LTTNG_ERR_NOMEM;
3418 goto end;
3419 }
3420
3421 reply_context->reply_sock_fd = *sock_fd;
3422 }
3423
3424 /* Safety net */
3425 LTTNG_ASSERT(session);
3426
3427 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
3428 if (session->active) {
3429 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3430 session->name);
3431 ret = cmd_stop_trace(session);
3432 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3433 /* Carry on with the destruction of the session. */
3434 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3435 session->name,
3436 lttng_strerror(-ret));
3437 destruction_last_error = (lttng_error_code) ret;
3438 }
3439 }
3440
3441 if (session->rotation_schedule_timer_enabled) {
3442 if (timer_session_rotation_schedule_timer_stop(session)) {
3443 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3444 session->name);
3445 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3446 }
3447 }
3448
3449 if (session->rotate_size) {
3450 try {
3451 the_rotation_thread_handle->unsubscribe_session_consumed_size_rotation(
3452 *session);
3453 } catch (const std::exception& e) {
3454 /* Continue the destruction of the session anyway. */
3455 ERR("Failed to unsubscribe rotation thread notification channel from consumed size condition during session destruction: %s",
3456 e.what());
3457 }
3458
3459 session->rotate_size = 0;
3460 }
3461
3462 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3463 /*
3464 * Perform a last rotation on destruction if rotations have
3465 * occurred during the session's lifetime.
3466 */
3467 ret = cmd_rotate_session(
3468 session, nullptr, false, LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3469 if (ret != LTTNG_OK) {
3470 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3471 session->name,
3472 lttng_strerror(-ret));
3473 destruction_last_error = (lttng_error_code) -ret;
3474 }
3475 if (reply_context) {
3476 reply_context->implicit_rotation_on_destroy = true;
3477 }
3478 } else if (session->has_been_started && session->current_trace_chunk) {
3479 /*
3480 * The user has not triggered a session rotation. However, to
3481 * ensure all data has been consumed, the session is rotated
3482 * to a 'null' trace chunk before it is destroyed.
3483 *
3484 * This is a "quiet" rotation meaning that no notification is
3485 * emitted and no renaming of the current trace chunk takes
3486 * place.
3487 */
3488 ret = cmd_rotate_session(
3489 session, nullptr, true, LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3490 /*
3491 * Rotation operations may not be supported by the kernel
3492 * tracer. Hence, do not consider this implicit rotation as
3493 * a session destruction error. The library has already stopped
3494 * the session and waited for pending data; there is nothing
3495 * left to do but complete the destruction of the session.
3496 */
3497 if (ret != LTTNG_OK && ret != -LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL) {
3498 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3499 session->name,
3500 lttng_strerror(ret));
3501 destruction_last_error = (lttng_error_code) -ret;
3502 }
3503 }
3504
3505 if (session->shm_path[0]) {
3506 /*
3507 * When a session is created with an explicit shm_path,
3508 * the consumer daemon will create its shared memory files
3509 * at that location and will *not* unlink them. This is normal
3510 * as the intention of that feature is to make it possible
3511 * to retrieve the content of those files should a crash occur.
3512 *
3513 * To ensure the content of those files can be used, the
3514 * sessiond daemon will replicate the content of the metadata
3515 * cache in a metadata file.
3516 *
3517 * On clean-up, it is expected that the consumer daemon will
3518 * unlink the shared memory files and that the session daemon
3519 * will unlink the metadata file. Then, the session's directory
3520 * in the shm path can be removed.
3521 *
3522 * Unfortunately, a flaw in the design of the sessiond's and
3523 * consumerd's tear down of channels makes it impossible to
3524 * determine when the sessiond _and_ the consumerd have both
3525 * destroyed their representation of a channel. For one, the
3526 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3527 * callbacks in both daemons.
3528 *
3529 * However, it is also impossible for the sessiond to know when
3530 * the consumer daemon is done destroying its channel(s) since
3531 * it occurs as a reaction to the closing of the channel's file
3532 * descriptor. There is no resulting communication initiated
3533 * from the consumerd to the sessiond to confirm that the
3534 * operation is completed (and was successful).
3535 *
3536 * Until this is all fixed, the session daemon checks for the
3537 * removal of the session's shm path which makes it possible
3538 * to safely advertise a session as having been destroyed.
3539 *
3540 * Prior to this fix, it was not possible to reliably save
3541 * a session making use of the --shm-path option, destroy it,
3542 * and load it again. This is because the creation of the
3543 * session would fail upon seeing the session's shm path
3544 * already in existence.
3545 *
3546 * Note that none of the error paths in the check for the
3547 * directory's existence return an error. This is normal
3548 * as there isn't much that can be done. The session will
3549 * be destroyed properly, except that we can't offer the
3550 * guarantee that the same session can be re-created.
3551 */
3552 current_completion_handler = &destroy_completion_handler.handler;
3553 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3554 session->shm_path,
3555 sizeof(destroy_completion_handler.shm_path));
3556 LTTNG_ASSERT(!ret);
3557 }
3558
3559 /*
3560 * The session is destroyed. However, note that the command context
3561 * still holds a reference to the session, thus delaying its destruction
3562 * _at least_ up to the point when that reference is released.
3563 */
3564 session_destroy(session);
3565 if (reply_context) {
3566 reply_context->destruction_status = destruction_last_error;
3567 ret = session_add_destroy_notifier(
3568 session, cmd_destroy_session_reply, (void *) reply_context);
3569 if (ret) {
3570 ret = LTTNG_ERR_FATAL;
3571 goto end;
3572 } else {
3573 *sock_fd = -1;
3574 }
3575 }
3576 ret = LTTNG_OK;
3577 end:
3578 return ret;
3579 }
3580
3581 /*
3582 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3583 */
3584 int cmd_register_consumer(struct ltt_session *session,
3585 enum lttng_domain_type domain,
3586 const char *sock_path,
3587 struct consumer_data *cdata)
3588 {
3589 int ret, sock;
3590 struct consumer_socket *socket = nullptr;
3591
3592 LTTNG_ASSERT(session);
3593 LTTNG_ASSERT(cdata);
3594 LTTNG_ASSERT(sock_path);
3595
3596 switch (domain) {
3597 case LTTNG_DOMAIN_KERNEL:
3598 {
3599 struct ltt_kernel_session *ksess = session->kernel_session;
3600
3601 LTTNG_ASSERT(ksess);
3602
3603 /* Can't register a consumer if there is already one */
3604 if (ksess->consumer_fds_sent != 0) {
3605 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3606 goto error;
3607 }
3608
3609 sock = lttcomm_connect_unix_sock(sock_path);
3610 if (sock < 0) {
3611 ret = LTTNG_ERR_CONNECT_FAIL;
3612 goto error;
3613 }
3614 cdata->cmd_sock = sock;
3615
3616 socket = consumer_allocate_socket(&cdata->cmd_sock);
3617 if (socket == nullptr) {
3618 ret = close(sock);
3619 if (ret < 0) {
3620 PERROR("close register consumer");
3621 }
3622 cdata->cmd_sock = -1;
3623 ret = LTTNG_ERR_FATAL;
3624 goto error;
3625 }
3626
3627 socket->lock = zmalloc<pthread_mutex_t>();
3628 if (socket->lock == nullptr) {
3629 PERROR("zmalloc pthread mutex");
3630 ret = LTTNG_ERR_FATAL;
3631 goto error;
3632 }
3633
3634 pthread_mutex_init(socket->lock, nullptr);
3635 socket->registered = 1;
3636
3637 lttng::urcu::read_lock_guard read_lock;
3638 consumer_add_socket(socket, ksess->consumer);
3639
3640 pthread_mutex_lock(&cdata->pid_mutex);
3641 cdata->pid = -1;
3642 pthread_mutex_unlock(&cdata->pid_mutex);
3643
3644 break;
3645 }
3646 default:
3647 /* TODO: Userspace tracing */
3648 ret = LTTNG_ERR_UND;
3649 goto error;
3650 }
3651
3652 return LTTNG_OK;
3653
3654 error:
3655 if (socket) {
3656 consumer_destroy_socket(socket);
3657 }
3658 return ret;
3659 }
3660
3661 /*
3662 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3663 */
3664 ssize_t cmd_list_domains(struct ltt_session *session, struct lttng_domain **domains)
3665 {
3666 int ret, index = 0;
3667 ssize_t nb_dom = 0;
3668 struct agent *agt;
3669 struct lttng_ht_iter iter;
3670
3671 if (session->kernel_session != nullptr) {
3672 DBG3("Listing domains found kernel domain");
3673 nb_dom++;
3674 }
3675
3676 if (session->ust_session != nullptr) {
3677 DBG3("Listing domains found UST global domain");
3678 nb_dom++;
3679
3680 lttng::urcu::read_lock_guard read_lock;
3681
3682 cds_lfht_for_each_entry (
3683 session->ust_session->agents->ht, &iter.iter, agt, node.node) {
3684 if (agt->being_used) {
3685 nb_dom++;
3686 }
3687 }
3688 }
3689
3690 if (!nb_dom) {
3691 goto end;
3692 }
3693
3694 *domains = calloc<lttng_domain>(nb_dom);
3695 if (*domains == nullptr) {
3696 ret = LTTNG_ERR_FATAL;
3697 goto error;
3698 }
3699
3700 if (session->kernel_session != nullptr) {
3701 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3702
3703 /* Kernel session buffer type is always GLOBAL */
3704 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3705
3706 index++;
3707 }
3708
3709 if (session->ust_session != nullptr) {
3710 (*domains)[index].type = LTTNG_DOMAIN_UST;
3711 (*domains)[index].buf_type = session->ust_session->buffer_type;
3712 index++;
3713
3714 {
3715 lttng::urcu::read_lock_guard read_lock;
3716
3717 cds_lfht_for_each_entry (
3718 session->ust_session->agents->ht, &iter.iter, agt, node.node) {
3719 if (agt->being_used) {
3720 (*domains)[index].type = agt->domain;
3721 (*domains)[index].buf_type =
3722 session->ust_session->buffer_type;
3723 index++;
3724 }
3725 }
3726 }
3727 }
3728 end:
3729 return nb_dom;
3730
3731 error:
3732 /* Return negative value to differentiate return code */
3733 return -ret;
3734 }
3735
3736 /*
3737 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3738 */
3739 enum lttng_error_code cmd_list_channels(enum lttng_domain_type domain,
3740 struct ltt_session *session,
3741 struct lttng_payload *payload)
3742 {
3743 int ret = 0;
3744 unsigned int i = 0;
3745 struct lttcomm_list_command_header cmd_header = {};
3746 size_t cmd_header_offset;
3747 enum lttng_error_code ret_code;
3748
3749 assert(session);
3750 assert(payload);
3751
3752 DBG("Listing channels for session %s", session->name);
3753
3754 cmd_header_offset = payload->buffer.size;
3755
3756 /* Reserve space for command reply header. */
3757 ret = lttng_dynamic_buffer_set_size(&payload->buffer,
3758 cmd_header_offset + sizeof(cmd_header));
3759 if (ret) {
3760 ret_code = LTTNG_ERR_NOMEM;
3761 goto end;
3762 }
3763
3764 switch (domain) {
3765 case LTTNG_DOMAIN_KERNEL:
3766 {
3767 /* Kernel channels */
3768 struct ltt_kernel_channel *kchan;
3769 if (session->kernel_session != nullptr) {
3770 cds_list_for_each_entry (
3771 kchan, &session->kernel_session->channel_list.head, list) {
3772 uint64_t discarded_events, lost_packets;
3773 struct lttng_channel_extended *extended;
3774
3775 extended = (struct lttng_channel_extended *)
3776 kchan->channel->attr.extended.ptr;
3777
3778 ret = get_kernel_runtime_stats(
3779 session, kchan, &discarded_events, &lost_packets);
3780 if (ret < 0) {
3781 ret_code = LTTNG_ERR_UNK;
3782 goto end;
3783 }
3784
3785 /*
3786 * Update the discarded_events and lost_packets
3787 * count for the channel
3788 */
3789 extended->discarded_events = discarded_events;
3790 extended->lost_packets = lost_packets;
3791
3792 ret = lttng_channel_serialize(kchan->channel, &payload->buffer);
3793 if (ret) {
3794 ERR("Failed to serialize lttng_channel: channel name = '%s'",
3795 kchan->channel->name);
3796 ret_code = LTTNG_ERR_UNK;
3797 goto end;
3798 }
3799
3800 i++;
3801 }
3802 }
3803 break;
3804 }
3805 case LTTNG_DOMAIN_UST:
3806 {
3807 struct lttng_ht_iter iter;
3808 struct ltt_ust_channel *uchan;
3809
3810 {
3811 lttng::urcu::read_lock_guard read_lock;
3812
3813 cds_lfht_for_each_entry (session->ust_session->domain_global.channels->ht,
3814 &iter.iter,
3815 uchan,
3816 node.node) {
3817 uint64_t discarded_events = 0, lost_packets = 0;
3818 struct lttng_channel *channel = nullptr;
3819 struct lttng_channel_extended *extended;
3820
3821 channel = trace_ust_channel_to_lttng_channel(uchan);
3822 if (!channel) {
3823 ret_code = LTTNG_ERR_NOMEM;
3824 goto end;
3825 }
3826
3827 extended = (struct lttng_channel_extended *)
3828 channel->attr.extended.ptr;
3829
3830 ret = get_ust_runtime_stats(
3831 session, uchan, &discarded_events, &lost_packets);
3832 if (ret < 0) {
3833 lttng_channel_destroy(channel);
3834 ret_code = LTTNG_ERR_UNK;
3835 goto end;
3836 }
3837
3838 extended->discarded_events = discarded_events;
3839 extended->lost_packets = lost_packets;
3840
3841 ret = lttng_channel_serialize(channel, &payload->buffer);
3842 if (ret) {
3843 ERR("Failed to serialize lttng_channel: channel name = '%s'",
3844 channel->name);
3845 lttng_channel_destroy(channel);
3846 ret_code = LTTNG_ERR_UNK;
3847 goto end;
3848 }
3849
3850 lttng_channel_destroy(channel);
3851 i++;
3852 }
3853 }
3854
3855 break;
3856 }
3857 default:
3858 break;
3859 }
3860
3861 if (i > UINT32_MAX) {
3862 ERR("Channel count would overflow the channel listing command's reply");
3863 ret_code = LTTNG_ERR_OVERFLOW;
3864 goto end;
3865 }
3866
3867 /* Update command reply header. */
3868 cmd_header.count = (uint32_t) i;
3869 memcpy(payload->buffer.data + cmd_header_offset, &cmd_header, sizeof(cmd_header));
3870 ret_code = LTTNG_OK;
3871
3872 end:
3873 return ret_code;
3874 }
3875
3876 /*
3877 * Command LTTNG_LIST_EVENTS processed by the client thread.
3878 */
3879 enum lttng_error_code cmd_list_events(enum lttng_domain_type domain,
3880 struct ltt_session *session,
3881 char *channel_name,
3882 struct lttng_payload *reply_payload)
3883 {
3884 int buffer_resize_ret;
3885 enum lttng_error_code ret_code = LTTNG_OK;
3886 struct lttcomm_list_command_header reply_command_header = {};
3887 size_t reply_command_header_offset;
3888 unsigned int nb_events = 0;
3889
3890 assert(reply_payload);
3891
3892 /* Reserve space for command reply header. */
3893 reply_command_header_offset = reply_payload->buffer.size;
3894 buffer_resize_ret = lttng_dynamic_buffer_set_size(
3895 &reply_payload->buffer,
3896 reply_command_header_offset + sizeof(struct lttcomm_list_command_header));
3897 if (buffer_resize_ret) {
3898 ret_code = LTTNG_ERR_NOMEM;
3899 goto end;
3900 }
3901
3902 switch (domain) {
3903 case LTTNG_DOMAIN_KERNEL:
3904 if (session->kernel_session != nullptr) {
3905 ret_code = list_lttng_kernel_events(
3906 channel_name, session->kernel_session, reply_payload, &nb_events);
3907 }
3908
3909 break;
3910 case LTTNG_DOMAIN_UST:
3911 {
3912 if (session->ust_session != nullptr) {
3913 ret_code =
3914 list_lttng_ust_global_events(channel_name,
3915 &session->ust_session->domain_global,
3916 reply_payload,
3917 &nb_events);
3918 }
3919
3920 break;
3921 }
3922 case LTTNG_DOMAIN_LOG4J:
3923 case LTTNG_DOMAIN_JUL:
3924 case LTTNG_DOMAIN_PYTHON:
3925 if (session->ust_session) {
3926 struct lttng_ht_iter iter;
3927 struct agent *agt;
3928
3929 lttng::urcu::read_lock_guard read_lock;
3930
3931 cds_lfht_for_each_entry (
3932 session->ust_session->agents->ht, &iter.iter, agt, node.node) {
3933 if (agt->domain == domain) {
3934 ret_code = list_lttng_agent_events(
3935 agt, reply_payload, &nb_events);
3936 break;
3937 }
3938 }
3939 }
3940 break;
3941 default:
3942 ret_code = LTTNG_ERR_UND;
3943 break;
3944 }
3945
3946 if (nb_events > UINT32_MAX) {
3947 ret_code = LTTNG_ERR_OVERFLOW;
3948 goto end;
3949 }
3950
3951 /* Update command reply header. */
3952 reply_command_header.count = (uint32_t) nb_events;
3953 memcpy(reply_payload->buffer.data + reply_command_header_offset,
3954 &reply_command_header,
3955 sizeof(reply_command_header));
3956
3957 end:
3958 return ret_code;
3959 }
3960
3961 /*
3962 * Using the session list, filled a lttng_session array to send back to the
3963 * client for session listing.
3964 *
3965 * The session list lock MUST be acquired before calling this function. Use
3966 * session_lock_list() and session_unlock_list().
3967 */
3968 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3969 size_t session_count,
3970 uid_t uid,
3971 gid_t gid)
3972 {
3973 int ret;
3974 unsigned int i = 0;
3975 struct ltt_session *session;
3976 struct ltt_session_list *list = session_get_list();
3977 struct lttng_session_extended *extended = (typeof(extended)) (&sessions[session_count]);
3978
3979 DBG("Getting all available session for UID %d GID %d", uid, gid);
3980 /*
3981 * Iterate over session list and append data after the control struct in
3982 * the buffer.
3983 */
3984 cds_list_for_each_entry (session, &list->head, list) {
3985 if (!session_get(session)) {
3986 continue;
3987 }
3988 /*
3989 * Only list the sessions the user can control.
3990 */
3991 if (!session_access_ok(session, uid) || session->destroyed) {
3992 session_put(session);
3993 continue;
3994 }
3995
3996 struct ltt_kernel_session *ksess = session->kernel_session;
3997 struct ltt_ust_session *usess = session->ust_session;
3998
3999 if (session->consumer->type == CONSUMER_DST_NET ||
4000 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
4001 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
4002 ret = build_network_session_path(
4003 sessions[i].path, sizeof(sessions[i].path), session);
4004 } else {
4005 ret = snprintf(sessions[i].path,
4006 sizeof(sessions[i].path),
4007 "%s",
4008 session->consumer->dst.session_root_path);
4009 }
4010 if (ret < 0) {
4011 PERROR("snprintf session path");
4012 session_put(session);
4013 continue;
4014 }
4015
4016 strncpy(sessions[i].name, session->name, NAME_MAX);
4017 sessions[i].name[NAME_MAX - 1] = '\0';
4018 sessions[i].enabled = session->active;
4019 sessions[i].snapshot_mode = session->snapshot_mode;
4020 sessions[i].live_timer_interval = session->live_timer;
4021 extended[i].creation_time.value = (uint64_t) session->creation_time;
4022 extended[i].creation_time.is_set = 1;
4023 i++;
4024 session_put(session);
4025 }
4026 }
4027
4028 /*
4029 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
4030 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
4031 */
4032 int cmd_data_pending(struct ltt_session *session)
4033 {
4034 int ret;
4035 struct ltt_kernel_session *ksess = session->kernel_session;
4036 struct ltt_ust_session *usess = session->ust_session;
4037
4038 LTTNG_ASSERT(session);
4039
4040 DBG("Data pending for session %s", session->name);
4041
4042 /* Session MUST be stopped to ask for data availability. */
4043 if (session->active) {
4044 ret = LTTNG_ERR_SESSION_STARTED;
4045 goto error;
4046 } else {
4047 /*
4048 * If stopped, just make sure we've started before else the above call
4049 * will always send that there is data pending.
4050 *
4051 * The consumer assumes that when the data pending command is received,
4052 * the trace has been started before or else no output data is written
4053 * by the streams which is a condition for data pending. So, this is
4054 * *VERY* important that we don't ask the consumer before a start
4055 * trace.
4056 */
4057 if (!session->has_been_started) {
4058 ret = 0;
4059 goto error;
4060 }
4061 }
4062
4063 /* A rotation is still pending, we have to wait. */
4064 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
4065 DBG("Rotate still pending for session %s", session->name);
4066 ret = 1;
4067 goto error;
4068 }
4069
4070 if (ksess && ksess->consumer) {
4071 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
4072 if (ret == 1) {
4073 /* Data is still being extracted for the kernel. */
4074 goto error;
4075 }
4076 }
4077
4078 if (usess && usess->consumer) {
4079 ret = consumer_is_data_pending(usess->id, usess->consumer);
4080 if (ret == 1) {
4081 /* Data is still being extracted for the kernel. */
4082 goto error;
4083 }
4084 }
4085
4086 /* Data is ready to be read by a viewer */
4087 ret = 0;
4088
4089 error:
4090 return ret;
4091 }
4092
4093 /*
4094 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
4095 *
4096 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4097 */
4098 int cmd_snapshot_add_output(struct ltt_session *session,
4099 const struct lttng_snapshot_output *output,
4100 uint32_t *id)
4101 {
4102 int ret;
4103 struct snapshot_output *new_output;
4104
4105 LTTNG_ASSERT(session);
4106 LTTNG_ASSERT(output);
4107
4108 DBG("Cmd snapshot add output for session %s", session->name);
4109
4110 /*
4111 * Can't create an output if the session is not set in no-output mode.
4112 */
4113 if (session->output_traces) {
4114 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4115 goto error;
4116 }
4117
4118 if (session->has_non_mmap_channel) {
4119 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
4120 goto error;
4121 }
4122
4123 /* Only one output is allowed until we have the "tee" feature. */
4124 if (session->snapshot.nb_output == 1) {
4125 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
4126 goto error;
4127 }
4128
4129 new_output = snapshot_output_alloc();
4130 if (!new_output) {
4131 ret = LTTNG_ERR_NOMEM;
4132 goto error;
4133 }
4134
4135 ret = snapshot_output_init(session,
4136 output->max_size,
4137 output->name,
4138 output->ctrl_url,
4139 output->data_url,
4140 session->consumer,
4141 new_output,
4142 &session->snapshot);
4143 if (ret < 0) {
4144 if (ret == -ENOMEM) {
4145 ret = LTTNG_ERR_NOMEM;
4146 } else {
4147 ret = LTTNG_ERR_INVALID;
4148 }
4149 goto free_error;
4150 }
4151
4152 snapshot_add_output(&session->snapshot, new_output);
4153 if (id) {
4154 *id = new_output->id;
4155 }
4156
4157 return LTTNG_OK;
4158
4159 free_error:
4160 snapshot_output_destroy(new_output);
4161 error:
4162 return ret;
4163 }
4164
4165 /*
4166 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
4167 *
4168 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4169 */
4170 int cmd_snapshot_del_output(struct ltt_session *session, const struct lttng_snapshot_output *output)
4171 {
4172 int ret;
4173 struct snapshot_output *sout = nullptr;
4174
4175 LTTNG_ASSERT(session);
4176 LTTNG_ASSERT(output);
4177
4178 lttng::urcu::read_lock_guard read_lock;
4179
4180 /*
4181 * Permission denied to create an output if the session is not
4182 * set in no output mode.
4183 */
4184 if (session->output_traces) {
4185 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4186 goto error;
4187 }
4188
4189 if (output->id) {
4190 DBG("Cmd snapshot del output id %" PRIu32 " for session %s",
4191 output->id,
4192 session->name);
4193 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
4194 } else if (*output->name != '\0') {
4195 DBG("Cmd snapshot del output name %s for session %s", output->name, session->name);
4196 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
4197 }
4198 if (!sout) {
4199 ret = LTTNG_ERR_INVALID;
4200 goto error;
4201 }
4202
4203 snapshot_delete_output(&session->snapshot, sout);
4204 snapshot_output_destroy(sout);
4205 ret = LTTNG_OK;
4206
4207 error:
4208 return ret;
4209 }
4210
4211 /*
4212 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
4213 *
4214 * If no output is available, outputs is untouched and 0 is returned.
4215 *
4216 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
4217 */
4218 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
4219 struct lttng_snapshot_output **outputs)
4220 {
4221 int ret, idx = 0;
4222 struct lttng_snapshot_output *list = nullptr;
4223 struct lttng_ht_iter iter;
4224 struct snapshot_output *output;
4225
4226 LTTNG_ASSERT(session);
4227 LTTNG_ASSERT(outputs);
4228
4229 DBG("Cmd snapshot list outputs for session %s", session->name);
4230
4231 /*
4232 * Permission denied to create an output if the session is not
4233 * set in no output mode.
4234 */
4235 if (session->output_traces) {
4236 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4237 goto end;
4238 }
4239
4240 if (session->snapshot.nb_output == 0) {
4241 ret = 0;
4242 goto end;
4243 }
4244
4245 list = calloc<lttng_snapshot_output>(session->snapshot.nb_output);
4246 if (!list) {
4247 ret = -LTTNG_ERR_NOMEM;
4248 goto end;
4249 }
4250
4251 /* Copy list from session to the new list object. */
4252 {
4253 lttng::urcu::read_lock_guard read_lock;
4254
4255 cds_lfht_for_each_entry (
4256 session->snapshot.output_ht->ht, &iter.iter, output, node.node) {
4257 LTTNG_ASSERT(output->consumer);
4258 list[idx].id = output->id;
4259 list[idx].max_size = output->max_size;
4260 if (lttng_strncpy(list[idx].name, output->name, sizeof(list[idx].name))) {
4261 ret = -LTTNG_ERR_INVALID;
4262 goto error;
4263 }
4264
4265 if (output->consumer->type == CONSUMER_DST_LOCAL) {
4266 if (lttng_strncpy(list[idx].ctrl_url,
4267 output->consumer->dst.session_root_path,
4268 sizeof(list[idx].ctrl_url))) {
4269 ret = -LTTNG_ERR_INVALID;
4270 goto error;
4271 }
4272 } else {
4273 /* Control URI. */
4274 ret = uri_to_str_url(&output->consumer->dst.net.control,
4275 list[idx].ctrl_url,
4276 sizeof(list[idx].ctrl_url));
4277 if (ret < 0) {
4278 ret = -LTTNG_ERR_NOMEM;
4279 goto error;
4280 }
4281
4282 /* Data URI. */
4283 ret = uri_to_str_url(&output->consumer->dst.net.data,
4284 list[idx].data_url,
4285 sizeof(list[idx].data_url));
4286 if (ret < 0) {
4287 ret = -LTTNG_ERR_NOMEM;
4288 goto error;
4289 }
4290 }
4291
4292 idx++;
4293 }
4294 }
4295
4296 *outputs = list;
4297 list = nullptr;
4298 ret = session->snapshot.nb_output;
4299 error:
4300 free(list);
4301 end:
4302 return ret;
4303 }
4304
4305 /*
4306 * Check if we can regenerate the metadata for this session.
4307 * Only kernel, UST per-uid and non-live sessions are supported.
4308 *
4309 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
4310 */
4311 static int check_regenerate_metadata_support(struct ltt_session *session)
4312 {
4313 int ret;
4314
4315 LTTNG_ASSERT(session);
4316
4317 if (session->live_timer != 0) {
4318 ret = LTTNG_ERR_LIVE_SESSION;
4319 goto end;
4320 }
4321 if (!session->active) {
4322 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4323 goto end;
4324 }
4325 if (session->ust_session) {
4326 switch (session->ust_session->buffer_type) {
4327 case LTTNG_BUFFER_PER_UID:
4328 break;
4329 case LTTNG_BUFFER_PER_PID:
4330 ret = LTTNG_ERR_PER_PID_SESSION;
4331 goto end;
4332 default:
4333 abort();
4334 ret = LTTNG_ERR_UNK;
4335 goto end;
4336 }
4337 }
4338 if (session->consumer->type == CONSUMER_DST_NET &&
4339 session->consumer->relay_minor_version < 8) {
4340 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
4341 goto end;
4342 }
4343 ret = 0;
4344
4345 end:
4346 return ret;
4347 }
4348
4349 /*
4350 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4351 *
4352 * Ask the consumer to truncate the existing metadata file(s) and
4353 * then regenerate the metadata. Live and per-pid sessions are not
4354 * supported and return an error.
4355 *
4356 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4357 */
4358 int cmd_regenerate_metadata(struct ltt_session *session)
4359 {
4360 int ret;
4361
4362 LTTNG_ASSERT(session);
4363
4364 ret = check_regenerate_metadata_support(session);
4365 if (ret) {
4366 goto end;
4367 }
4368
4369 if (session->kernel_session) {
4370 ret = kernctl_session_regenerate_metadata(session->kernel_session->fd);
4371 if (ret < 0) {
4372 ERR("Failed to regenerate the kernel metadata");
4373 goto end;
4374 }
4375 }
4376
4377 if (session->ust_session) {
4378 ret = trace_ust_regenerate_metadata(session->ust_session);
4379 if (ret < 0) {
4380 ERR("Failed to regenerate the UST metadata");
4381 goto end;
4382 }
4383 }
4384 DBG("Cmd metadata regenerate for session %s", session->name);
4385 ret = LTTNG_OK;
4386
4387 end:
4388 return ret;
4389 }
4390
4391 /*
4392 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4393 *
4394 * Ask the tracer to regenerate a new statedump.
4395 *
4396 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4397 */
4398 int cmd_regenerate_statedump(struct ltt_session *session)
4399 {
4400 int ret;
4401
4402 LTTNG_ASSERT(session);
4403
4404 if (!session->active) {
4405 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4406 goto end;
4407 }
4408
4409 if (session->kernel_session) {
4410 ret = kernctl_session_regenerate_statedump(session->kernel_session->fd);
4411 /*
4412 * Currently, the statedump in kernel can only fail if out
4413 * of memory.
4414 */
4415 if (ret < 0) {
4416 if (ret == -ENOMEM) {
4417 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4418 } else {
4419 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4420 }
4421 ERR("Failed to regenerate the kernel statedump");
4422 goto end;
4423 }
4424 }
4425
4426 if (session->ust_session) {
4427 ret = ust_app_regenerate_statedump_all(session->ust_session);
4428 /*
4429 * Currently, the statedump in UST always returns 0.
4430 */
4431 if (ret < 0) {
4432 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4433 ERR("Failed to regenerate the UST statedump");
4434 goto end;
4435 }
4436 }
4437 DBG("Cmd regenerate statedump for session %s", session->name);
4438 ret = LTTNG_OK;
4439
4440 end:
4441 return ret;
4442 }
4443
4444 static enum lttng_error_code
4445 synchronize_tracer_notifier_register(struct notification_thread_handle *notification_thread,
4446 struct lttng_trigger *trigger,
4447 const struct lttng_credentials *cmd_creds)
4448 {
4449 enum lttng_error_code ret_code;
4450 const struct lttng_condition *condition = lttng_trigger_get_const_condition(trigger);
4451 const char *trigger_name;
4452 uid_t trigger_owner;
4453 enum lttng_trigger_status trigger_status;
4454 const enum lttng_domain_type trigger_domain =
4455 lttng_trigger_get_underlying_domain_type_restriction(trigger);
4456
4457 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner);
4458 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4459
4460 LTTNG_ASSERT(condition);
4461 LTTNG_ASSERT(lttng_condition_get_type(condition) ==
4462 LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES);
4463
4464 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4465 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4466
4467 session_lock_list();
4468 switch (trigger_domain) {
4469 case LTTNG_DOMAIN_KERNEL:
4470 {
4471 ret_code = kernel_register_event_notifier(trigger, cmd_creds);
4472 if (ret_code != LTTNG_OK) {
4473 enum lttng_error_code notif_thread_unregister_ret;
4474
4475 notif_thread_unregister_ret =
4476 notification_thread_command_unregister_trigger(notification_thread,
4477 trigger);
4478
4479 if (notif_thread_unregister_ret != LTTNG_OK) {
4480 /* Return the original error code. */
4481 ERR("Failed to unregister trigger from notification thread during error recovery: trigger name = '%s', trigger owner uid = %d, error code = %d",
4482 trigger_name,
4483 (int) trigger_owner,
4484 ret_code);
4485 }
4486
4487 goto end_unlock_session_list;
4488 }
4489 break;
4490 }
4491 case LTTNG_DOMAIN_UST:
4492 ust_app_global_update_all_event_notifier_rules();
4493 break;
4494 case LTTNG_DOMAIN_JUL:
4495 case LTTNG_DOMAIN_LOG4J:
4496 case LTTNG_DOMAIN_PYTHON:
4497 {
4498 /* Agent domains. */
4499 struct agent *agt = agent_find_by_event_notifier_domain(trigger_domain);
4500
4501 if (!agt) {
4502 agt = agent_create(trigger_domain);
4503 if (!agt) {
4504 ret_code = LTTNG_ERR_NOMEM;
4505 goto end_unlock_session_list;
4506 }
4507
4508 agent_add(agt, the_trigger_agents_ht_by_domain);
4509 }
4510
4511 ret_code = (lttng_error_code) trigger_agent_enable(trigger, agt);
4512 if (ret_code != LTTNG_OK) {
4513 goto end_unlock_session_list;
4514 }
4515
4516 break;
4517 }
4518 case LTTNG_DOMAIN_NONE:
4519 default:
4520 abort();
4521 }
4522
4523 ret_code = LTTNG_OK;
4524 end_unlock_session_list:
4525 session_unlock_list();
4526 return ret_code;
4527 }
4528
4529 enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_creds,
4530 struct lttng_trigger *trigger,
4531 bool is_trigger_anonymous,
4532 struct notification_thread_handle *notification_thread,
4533 struct lttng_trigger **return_trigger)
4534 {
4535 enum lttng_error_code ret_code;
4536 const char *trigger_name;
4537 uid_t trigger_owner;
4538 enum lttng_trigger_status trigger_status;
4539
4540 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4541 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4542
4543 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner);
4544 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4545
4546 DBG("Running register trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4547 trigger_name,
4548 (int) trigger_owner,
4549 (int) lttng_credentials_get_uid(cmd_creds));
4550
4551 /*
4552 * Validate the trigger credentials against the command credentials.
4553 * Only the root user can register a trigger with non-matching
4554 * credentials.
4555 */
4556 if (!lttng_credentials_is_equal_uid(lttng_trigger_get_credentials(trigger), cmd_creds)) {
4557 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4558 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4559 trigger_name,
4560 (int) trigger_owner,
4561 (int) lttng_credentials_get_uid(cmd_creds));
4562 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4563 goto end;
4564 }
4565 }
4566
4567 /*
4568 * The bytecode generation also serves as a validation step for the
4569 * bytecode expressions.
4570 */
4571 ret_code = lttng_trigger_generate_bytecode(trigger, cmd_creds);
4572 if (ret_code != LTTNG_OK) {
4573 ERR("Failed to generate bytecode of trigger: trigger name = '%s', trigger owner uid = %d, error code = %d",
4574 trigger_name,
4575 (int) trigger_owner,
4576 ret_code);
4577 goto end;
4578 }
4579
4580 /*
4581 * A reference to the trigger is acquired by the notification thread.
4582 * It is safe to return the same trigger to the caller since it the
4583 * other user holds a reference.
4584 *
4585 * The trigger is modified during the execution of the
4586 * "register trigger" command. However, by the time the command returns,
4587 * it is safe to use without any locking as its properties are
4588 * immutable.
4589 */
4590 ret_code = notification_thread_command_register_trigger(
4591 notification_thread, trigger, is_trigger_anonymous);
4592 if (ret_code != LTTNG_OK) {
4593 DBG("Failed to register trigger to notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4594 trigger_name,
4595 (int) trigger_owner,
4596 ret_code);
4597 goto end;
4598 }
4599
4600 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4601 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4602
4603 /*
4604 * Synchronize tracers if the trigger adds an event notifier.
4605 */
4606 if (lttng_trigger_needs_tracer_notifier(trigger)) {
4607 ret_code = synchronize_tracer_notifier_register(
4608 notification_thread, trigger, cmd_creds);
4609 if (ret_code != LTTNG_OK) {
4610 ERR("Error registering tracer notifier: %s", lttng_strerror(-ret_code));
4611 goto end;
4612 }
4613 }
4614
4615 /*
4616 * Return an updated trigger to the client.
4617 *
4618 * Since a modified version of the same trigger is returned, acquire a
4619 * reference to the trigger so the caller doesn't have to care if those
4620 * are distinct instances or not.
4621 */
4622 if (ret_code == LTTNG_OK) {
4623 lttng_trigger_get(trigger);
4624 *return_trigger = trigger;
4625 /* Ownership of trigger was transferred to caller. */
4626 trigger = nullptr;
4627 }
4628 end:
4629 return ret_code;
4630 }
4631
4632 static enum lttng_error_code
4633 synchronize_tracer_notifier_unregister(const struct lttng_trigger *trigger)
4634 {
4635 enum lttng_error_code ret_code;
4636 const struct lttng_condition *condition = lttng_trigger_get_const_condition(trigger);
4637 const enum lttng_domain_type trigger_domain =
4638 lttng_trigger_get_underlying_domain_type_restriction(trigger);
4639
4640 LTTNG_ASSERT(condition);
4641 LTTNG_ASSERT(lttng_condition_get_type(condition) ==
4642 LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES);
4643
4644 session_lock_list();
4645 switch (trigger_domain) {
4646 case LTTNG_DOMAIN_KERNEL:
4647 ret_code = kernel_unregister_event_notifier(trigger);
4648 if (ret_code != LTTNG_OK) {
4649 goto end_unlock_session_list;
4650 }
4651
4652 break;
4653 case LTTNG_DOMAIN_UST:
4654 ust_app_global_update_all_event_notifier_rules();
4655 break;
4656 case LTTNG_DOMAIN_JUL:
4657 case LTTNG_DOMAIN_LOG4J:
4658 case LTTNG_DOMAIN_PYTHON:
4659 {
4660 /* Agent domains. */
4661 struct agent *agt = agent_find_by_event_notifier_domain(trigger_domain);
4662
4663 /*
4664 * This trigger was never registered in the first place. Calling
4665 * this function under those circumstances is an internal error.
4666 */
4667 LTTNG_ASSERT(agt);
4668 ret_code = (lttng_error_code) trigger_agent_disable(trigger, agt);
4669 if (ret_code != LTTNG_OK) {
4670 goto end_unlock_session_list;
4671 }
4672
4673 break;
4674 }
4675 case LTTNG_DOMAIN_NONE:
4676 default:
4677 abort();
4678 }
4679
4680 ret_code = LTTNG_OK;
4681
4682 end_unlock_session_list:
4683 session_unlock_list();
4684 return ret_code;
4685 }
4686
4687 enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd_creds,
4688 const struct lttng_trigger *trigger,
4689 struct notification_thread_handle *notification_thread)
4690 {
4691 enum lttng_error_code ret_code;
4692 const char *trigger_name;
4693 uid_t trigger_owner;
4694 enum lttng_trigger_status trigger_status;
4695 struct lttng_trigger *sessiond_trigger = nullptr;
4696
4697 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4698 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4699 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner);
4700 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4701
4702 DBG("Running unregister trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4703 trigger_name,
4704 (int) trigger_owner,
4705 (int) lttng_credentials_get_uid(cmd_creds));
4706
4707 /*
4708 * Validate the trigger credentials against the command credentials.
4709 * Only the root user can unregister a trigger with non-matching
4710 * credentials.
4711 */
4712 if (!lttng_credentials_is_equal_uid(lttng_trigger_get_credentials(trigger), cmd_creds)) {
4713 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4714 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4715 trigger_name,
4716 (int) trigger_owner,
4717 (int) lttng_credentials_get_uid(cmd_creds));
4718 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4719 goto end;
4720 }
4721 }
4722
4723 /* Fetch the sessiond side trigger object. */
4724 ret_code = notification_thread_command_get_trigger(
4725 notification_thread, trigger, &sessiond_trigger);
4726 if (ret_code != LTTNG_OK) {
4727 DBG("Failed to get trigger from notification thread during unregister: trigger name = '%s', trigger owner uid = %d, error code = %d",
4728 trigger_name,
4729 (int) trigger_owner,
4730 ret_code);
4731 goto end;
4732 }
4733
4734 LTTNG_ASSERT(sessiond_trigger);
4735
4736 /*
4737 * From this point on, no matter what, consider the trigger
4738 * unregistered.
4739 *
4740 * We set the unregistered state of the sessiond side trigger object in
4741 * the client thread since we want to minimize the possibility of the
4742 * notification thread being stalled due to a long execution of an
4743 * action that required the trigger lock.
4744 */
4745 lttng_trigger_set_as_unregistered(sessiond_trigger);
4746
4747 ret_code = notification_thread_command_unregister_trigger(notification_thread, trigger);
4748 if (ret_code != LTTNG_OK) {
4749 DBG("Failed to unregister trigger from notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4750 trigger_name,
4751 (int) trigger_owner,
4752 ret_code);
4753 goto end;
4754 }
4755
4756 /*
4757 * Synchronize tracers if the trigger removes an event notifier.
4758 * Do this even if the trigger unregistration failed to at least stop
4759 * the tracers from producing notifications associated with this
4760 * event notifier.
4761 */
4762 if (lttng_trigger_needs_tracer_notifier(trigger)) {
4763 ret_code = synchronize_tracer_notifier_unregister(trigger);
4764 if (ret_code != LTTNG_OK) {
4765 ERR("Error unregistering trigger to tracer.");
4766 goto end;
4767 }
4768 }
4769
4770 end:
4771 lttng_trigger_put(sessiond_trigger);
4772 return ret_code;
4773 }
4774
4775 enum lttng_error_code cmd_list_triggers(struct command_ctx *cmd_ctx,
4776 struct notification_thread_handle *notification_thread,
4777 struct lttng_triggers **return_triggers)
4778 {
4779 int ret;
4780 enum lttng_error_code ret_code;
4781 struct lttng_triggers *triggers = nullptr;
4782
4783 /* Get the set of triggers from the notification thread. */
4784 ret_code = notification_thread_command_list_triggers(
4785 notification_thread, cmd_ctx->creds.uid, &triggers);
4786 if (ret_code != LTTNG_OK) {
4787 goto end;
4788 }
4789
4790 ret = lttng_triggers_remove_hidden_triggers(triggers);
4791 if (ret) {
4792 ret_code = LTTNG_ERR_UNK;
4793 goto end;
4794 }
4795
4796 *return_triggers = triggers;
4797 triggers = nullptr;
4798 ret_code = LTTNG_OK;
4799 end:
4800 lttng_triggers_destroy(triggers);
4801 return ret_code;
4802 }
4803
4804 enum lttng_error_code
4805 cmd_execute_error_query(const struct lttng_credentials *cmd_creds,
4806 const struct lttng_error_query *query,
4807 struct lttng_error_query_results **_results,
4808 struct notification_thread_handle *notification_thread)
4809 {
4810 enum lttng_error_code ret_code;
4811 const struct lttng_trigger *query_target_trigger;
4812 const struct lttng_action *query_target_action = nullptr;
4813 struct lttng_trigger *matching_trigger = nullptr;
4814 const char *trigger_name;
4815 uid_t trigger_owner;
4816 enum lttng_trigger_status trigger_status;
4817 struct lttng_error_query_results *results = nullptr;
4818
4819 switch (lttng_error_query_get_target_type(query)) {
4820 case LTTNG_ERROR_QUERY_TARGET_TYPE_TRIGGER:
4821 query_target_trigger = lttng_error_query_trigger_borrow_target(query);
4822 break;
4823 case LTTNG_ERROR_QUERY_TARGET_TYPE_CONDITION:
4824 query_target_trigger = lttng_error_query_condition_borrow_target(query);
4825 break;
4826 case LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION:
4827 query_target_trigger = lttng_error_query_action_borrow_trigger_target(query);
4828 break;
4829 default:
4830 abort();
4831 }
4832
4833 LTTNG_ASSERT(query_target_trigger);
4834
4835 ret_code = notification_thread_command_get_trigger(
4836 notification_thread, query_target_trigger, &matching_trigger);
4837 if (ret_code != LTTNG_OK) {
4838 goto end;
4839 }
4840
4841 /* No longer needed. */
4842 query_target_trigger = nullptr;
4843
4844 if (lttng_error_query_get_target_type(query) == LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION) {
4845 /* Get the sessiond-side version of the target action. */
4846 query_target_action =
4847 lttng_error_query_action_borrow_action_target(query, matching_trigger);
4848 }
4849
4850 trigger_status = lttng_trigger_get_name(matching_trigger, &trigger_name);
4851 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4852 trigger_status = lttng_trigger_get_owner_uid(matching_trigger, &trigger_owner);
4853 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4854
4855 results = lttng_error_query_results_create();
4856 if (!results) {
4857 ret_code = LTTNG_ERR_NOMEM;
4858 goto end;
4859 }
4860
4861 DBG("Running \"execute error query\" command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4862 trigger_name,
4863 (int) trigger_owner,
4864 (int) lttng_credentials_get_uid(cmd_creds));
4865
4866 /*
4867 * Validate the trigger credentials against the command credentials.
4868 * Only the root user can target a trigger with non-matching
4869 * credentials.
4870 */
4871 if (!lttng_credentials_is_equal_uid(lttng_trigger_get_credentials(matching_trigger),
4872 cmd_creds)) {
4873 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4874 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4875 trigger_name,
4876 (int) trigger_owner,
4877 (int) lttng_credentials_get_uid(cmd_creds));
4878 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4879 goto end;
4880 }
4881 }
4882
4883 switch (lttng_error_query_get_target_type(query)) {
4884 case LTTNG_ERROR_QUERY_TARGET_TYPE_TRIGGER:
4885 trigger_status = lttng_trigger_add_error_results(matching_trigger, results);
4886
4887 switch (trigger_status) {
4888 case LTTNG_TRIGGER_STATUS_OK:
4889 break;
4890 default:
4891 ret_code = LTTNG_ERR_UNK;
4892 goto end;
4893 }
4894
4895 break;
4896 case LTTNG_ERROR_QUERY_TARGET_TYPE_CONDITION:
4897 {
4898 trigger_status =
4899 lttng_trigger_condition_add_error_results(matching_trigger, results);
4900
4901 switch (trigger_status) {
4902 case LTTNG_TRIGGER_STATUS_OK:
4903 break;
4904 default:
4905 ret_code = LTTNG_ERR_UNK;
4906 goto end;
4907 }
4908
4909 break;
4910 }
4911 case LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION:
4912 {
4913 const enum lttng_action_status action_status =
4914 lttng_action_add_error_query_results(query_target_action, results);
4915
4916 switch (action_status) {
4917 case LTTNG_ACTION_STATUS_OK:
4918 break;
4919 default:
4920 ret_code = LTTNG_ERR_UNK;
4921 goto end;
4922 }
4923
4924 break;
4925 }
4926 default:
4927 abort();
4928 break;
4929 }
4930
4931 *_results = results;
4932 results = nullptr;
4933 ret_code = LTTNG_OK;
4934 end:
4935 lttng_trigger_put(matching_trigger);
4936 lttng_error_query_results_destroy(results);
4937 return ret_code;
4938 }
4939
4940 /*
4941 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4942 * snapshot output is *not* set with a remote destination.
4943 *
4944 * Return LTTNG_OK on success or a LTTNG_ERR code.
4945 */
4946 static enum lttng_error_code set_relayd_for_snapshot(struct consumer_output *output,
4947 const struct ltt_session *session)
4948 {
4949 enum lttng_error_code status = LTTNG_OK;
4950 struct lttng_ht_iter iter;
4951 struct consumer_socket *socket;
4952 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4953 const char *base_path;
4954
4955 LTTNG_ASSERT(output);
4956 LTTNG_ASSERT(session);
4957
4958 DBG2("Set relayd object from snapshot output");
4959
4960 if (session->current_trace_chunk) {
4961 enum lttng_trace_chunk_status chunk_status = lttng_trace_chunk_get_id(
4962 session->current_trace_chunk, &current_chunk_id.value);
4963
4964 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
4965 current_chunk_id.is_set = true;
4966 } else {
4967 ERR("Failed to get current trace chunk id");
4968 status = LTTNG_ERR_UNK;
4969 goto error;
4970 }
4971 }
4972
4973 /* Ignore if snapshot consumer output is not network. */
4974 if (output->type != CONSUMER_DST_NET) {
4975 goto error;
4976 }
4977
4978 /*
4979 * The snapshot record URI base path overrides the session
4980 * base path.
4981 */
4982 if (output->dst.net.control.subdir[0] != '\0') {
4983 base_path = output->dst.net.control.subdir;
4984 } else {
4985 base_path = session->base_path;
4986 }
4987
4988 /*
4989 * For each consumer socket, create and send the relayd object of the
4990 * snapshot output.
4991 */
4992 {
4993 lttng::urcu::read_lock_guard read_lock;
4994
4995 cds_lfht_for_each_entry (output->socks->ht, &iter.iter, socket, node.node) {
4996 pthread_mutex_lock(socket->lock);
4997 status = send_consumer_relayd_sockets(
4998 session->id,
4999 output,
5000 socket,
5001 session->name,
5002 session->hostname,
5003 base_path,
5004 session->live_timer,
5005 current_chunk_id.is_set ? &current_chunk_id.value : nullptr,
5006 session->creation_time,
5007 session->name_contains_creation_time);
5008 pthread_mutex_unlock(socket->lock);
5009 if (status != LTTNG_OK) {
5010 goto error;
5011 }
5012 }
5013 }
5014
5015 error:
5016 return status;
5017 }
5018
5019 /*
5020 * Record a kernel snapshot.
5021 *
5022 * Return LTTNG_OK on success or a LTTNG_ERR code.
5023 */
5024 static enum lttng_error_code record_kernel_snapshot(struct ltt_kernel_session *ksess,
5025 const struct consumer_output *output,
5026 const struct ltt_session *session,
5027 uint64_t nb_packets_per_stream)
5028 {
5029 enum lttng_error_code status;
5030
5031 LTTNG_ASSERT(ksess);
5032 LTTNG_ASSERT(output);
5033 LTTNG_ASSERT(session);
5034
5035 status = kernel_snapshot_record(ksess, output, nb_packets_per_stream);
5036 return status;
5037 }
5038
5039 /*
5040 * Record a UST snapshot.
5041 *
5042 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5043 */
5044 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
5045 const struct consumer_output *output,
5046 const struct ltt_session *session,
5047 uint64_t nb_packets_per_stream)
5048 {
5049 enum lttng_error_code status;
5050
5051 LTTNG_ASSERT(usess);
5052 LTTNG_ASSERT(output);
5053 LTTNG_ASSERT(session);
5054
5055 status = ust_app_snapshot_record(usess, output, nb_packets_per_stream);
5056 return status;
5057 }
5058
5059 static uint64_t get_session_size_one_more_packet_per_stream(const struct ltt_session *session,
5060 uint64_t cur_nr_packets)
5061 {
5062 uint64_t tot_size = 0;
5063
5064 if (session->kernel_session) {
5065 struct ltt_kernel_channel *chan;
5066 const struct ltt_kernel_session *ksess = session->kernel_session;
5067
5068 cds_list_for_each_entry (chan, &ksess->channel_list.head, list) {
5069 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
5070 /*
5071 * Don't take channel into account if we
5072 * already grab all its packets.
5073 */
5074 continue;
5075 }
5076 tot_size += chan->channel->attr.subbuf_size * chan->stream_count;
5077 }
5078 }
5079
5080 if (session->ust_session) {
5081 const struct ltt_ust_session *usess = session->ust_session;
5082
5083 tot_size += ust_app_get_size_one_more_packet_per_stream(usess, cur_nr_packets);
5084 }
5085
5086 return tot_size;
5087 }
5088
5089 /*
5090 * Calculate the number of packets we can grab from each stream that
5091 * fits within the overall snapshot max size.
5092 *
5093 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
5094 * the number of packets per stream.
5095 *
5096 * TODO: this approach is not perfect: we consider the worse case
5097 * (packet filling the sub-buffers) as an upper bound, but we could do
5098 * better if we do this calculation while we actually grab the packet
5099 * content: we would know how much padding we don't actually store into
5100 * the file.
5101 *
5102 * This algorithm is currently bounded by the number of packets per
5103 * stream.
5104 *
5105 * Since we call this algorithm before actually grabbing the data, it's
5106 * an approximation: for instance, applications could appear/disappear
5107 * in between this call and actually grabbing data.
5108 */
5109 static int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
5110 uint64_t max_size)
5111 {
5112 int64_t size_left;
5113 uint64_t cur_nb_packets = 0;
5114
5115 if (!max_size) {
5116 return 0; /* Infinite */
5117 }
5118
5119 size_left = max_size;
5120 for (;;) {
5121 uint64_t one_more_packet_tot_size;
5122
5123 one_more_packet_tot_size =
5124 get_session_size_one_more_packet_per_stream(session, cur_nb_packets);
5125 if (!one_more_packet_tot_size) {
5126 /* We are already grabbing all packets. */
5127 break;
5128 }
5129 size_left -= one_more_packet_tot_size;
5130 if (size_left < 0) {
5131 break;
5132 }
5133 cur_nb_packets++;
5134 }
5135 if (!cur_nb_packets && size_left != max_size) {
5136 /* Not enough room to grab one packet of each stream, error. */
5137 return -1;
5138 }
5139 return cur_nb_packets;
5140 }
5141
5142 static enum lttng_error_code snapshot_record(struct ltt_session *session,
5143 const struct snapshot_output *snapshot_output)
5144 {
5145 int64_t nb_packets_per_stream;
5146 char snapshot_chunk_name[LTTNG_NAME_MAX];
5147 int ret;
5148 enum lttng_error_code ret_code = LTTNG_OK;
5149 struct lttng_trace_chunk *snapshot_trace_chunk;
5150 struct consumer_output *original_ust_consumer_output = nullptr;
5151 struct consumer_output *original_kernel_consumer_output = nullptr;
5152 struct consumer_output *snapshot_ust_consumer_output = nullptr;
5153 struct consumer_output *snapshot_kernel_consumer_output = nullptr;
5154
5155 ret = snprintf(snapshot_chunk_name,
5156 sizeof(snapshot_chunk_name),
5157 "%s-%s-%" PRIu64,
5158 snapshot_output->name,
5159 snapshot_output->datetime,
5160 snapshot_output->nb_snapshot);
5161 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
5162 ERR("Failed to format snapshot name");
5163 ret_code = LTTNG_ERR_INVALID;
5164 goto error;
5165 }
5166 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
5167 snapshot_output->name,
5168 session->name,
5169 snapshot_chunk_name);
5170 if (!session->kernel_session && !session->ust_session) {
5171 ERR("Failed to record snapshot as no channels exist");
5172 ret_code = LTTNG_ERR_NO_CHANNEL;
5173 goto error;
5174 }
5175
5176 if (session->kernel_session) {
5177 original_kernel_consumer_output = session->kernel_session->consumer;
5178 snapshot_kernel_consumer_output = consumer_copy_output(snapshot_output->consumer);
5179 strcpy(snapshot_kernel_consumer_output->chunk_path, snapshot_chunk_name);
5180
5181 /* Copy the original domain subdir. */
5182 strcpy(snapshot_kernel_consumer_output->domain_subdir,
5183 original_kernel_consumer_output->domain_subdir);
5184
5185 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
5186 original_kernel_consumer_output);
5187 if (ret < 0) {
5188 ERR("Failed to copy consumer sockets from snapshot output configuration");
5189 ret_code = LTTNG_ERR_NOMEM;
5190 goto error;
5191 }
5192 ret_code = set_relayd_for_snapshot(snapshot_kernel_consumer_output, session);
5193 if (ret_code != LTTNG_OK) {
5194 ERR("Failed to setup relay daemon for kernel tracer snapshot");
5195 goto error;
5196 }
5197 session->kernel_session->consumer = snapshot_kernel_consumer_output;
5198 }
5199 if (session->ust_session) {
5200 original_ust_consumer_output = session->ust_session->consumer;
5201 snapshot_ust_consumer_output = consumer_copy_output(snapshot_output->consumer);
5202 strcpy(snapshot_ust_consumer_output->chunk_path, snapshot_chunk_name);
5203
5204 /* Copy the original domain subdir. */
5205 strcpy(snapshot_ust_consumer_output->domain_subdir,
5206 original_ust_consumer_output->domain_subdir);
5207
5208 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
5209 original_ust_consumer_output);
5210 if (ret < 0) {
5211 ERR("Failed to copy consumer sockets from snapshot output configuration");
5212 ret_code = LTTNG_ERR_NOMEM;
5213 goto error;
5214 }
5215 ret_code = set_relayd_for_snapshot(snapshot_ust_consumer_output, session);
5216 if (ret_code != LTTNG_OK) {
5217 ERR("Failed to setup relay daemon for userspace tracer snapshot");
5218 goto error;
5219 }
5220 session->ust_session->consumer = snapshot_ust_consumer_output;
5221 }
5222
5223 snapshot_trace_chunk = session_create_new_trace_chunk(
5224 session,
5225 snapshot_kernel_consumer_output ?: snapshot_ust_consumer_output,
5226 consumer_output_get_base_path(snapshot_output->consumer),
5227 snapshot_chunk_name);
5228 if (!snapshot_trace_chunk) {
5229 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
5230 session->name);
5231 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
5232 goto error;
5233 }
5234 LTTNG_ASSERT(!session->current_trace_chunk);
5235 ret = session_set_trace_chunk(session, snapshot_trace_chunk, nullptr);
5236 lttng_trace_chunk_put(snapshot_trace_chunk);
5237 snapshot_trace_chunk = nullptr;
5238 if (ret) {
5239 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
5240 session->name);
5241 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5242 goto error;
5243 }
5244
5245 nb_packets_per_stream =
5246 get_session_nb_packets_per_stream(session, snapshot_output->max_size);
5247 if (nb_packets_per_stream < 0) {
5248 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
5249 goto error_close_trace_chunk;
5250 }
5251
5252 if (session->kernel_session) {
5253 ret_code = record_kernel_snapshot(session->kernel_session,
5254 snapshot_kernel_consumer_output,
5255 session,
5256 nb_packets_per_stream);
5257 if (ret_code != LTTNG_OK) {
5258 goto error_close_trace_chunk;
5259 }
5260 }
5261
5262 if (session->ust_session) {
5263 ret_code = record_ust_snapshot(session->ust_session,
5264 snapshot_ust_consumer_output,
5265 session,
5266 nb_packets_per_stream);
5267 if (ret_code != LTTNG_OK) {
5268 goto error_close_trace_chunk;
5269 }
5270 }
5271
5272 error_close_trace_chunk:
5273 if (session_set_trace_chunk(session, nullptr, &snapshot_trace_chunk)) {
5274 ERR("Failed to release the current trace chunk of session \"%s\"", session->name);
5275 ret_code = LTTNG_ERR_UNK;
5276 }
5277
5278 if (session_close_trace_chunk(session,
5279 snapshot_trace_chunk,
5280 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION,
5281 nullptr)) {
5282 /*
5283 * Don't goto end; make sure the chunk is closed for the session
5284 * to allow future snapshots.
5285 */
5286 ERR("Failed to close snapshot trace chunk of session \"%s\"", session->name);
5287 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5288 }
5289
5290 lttng_trace_chunk_put(snapshot_trace_chunk);
5291 snapshot_trace_chunk = nullptr;
5292 error:
5293 if (original_ust_consumer_output) {
5294 session->ust_session->consumer = original_ust_consumer_output;
5295 }
5296 if (original_kernel_consumer_output) {
5297 session->kernel_session->consumer = original_kernel_consumer_output;
5298 }
5299 consumer_output_put(snapshot_ust_consumer_output);
5300 consumer_output_put(snapshot_kernel_consumer_output);
5301 return ret_code;
5302 }
5303
5304 /*
5305 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
5306 *
5307 * The wait parameter is ignored so this call always wait for the snapshot to
5308 * complete before returning.
5309 *
5310 * Return LTTNG_OK on success or else a LTTNG_ERR code.
5311 */
5312 int cmd_snapshot_record(struct ltt_session *session,
5313 const struct lttng_snapshot_output *output,
5314 int wait __attribute__((unused)))
5315 {
5316 enum lttng_error_code cmd_ret = LTTNG_OK;
5317 int ret;
5318 unsigned int snapshot_success = 0;
5319 char datetime[16];
5320 struct snapshot_output *tmp_output = nullptr;
5321
5322 LTTNG_ASSERT(session);
5323 LTTNG_ASSERT(output);
5324
5325 DBG("Cmd snapshot record for session %s", session->name);
5326
5327 /* Get the datetime for the snapshot output directory. */
5328 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime, sizeof(datetime));
5329 if (!ret) {
5330 cmd_ret = LTTNG_ERR_INVALID;
5331 goto error;
5332 }
5333
5334 /*
5335 * Permission denied to create an output if the session is not
5336 * set in no output mode.
5337 */
5338 if (session->output_traces) {
5339 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
5340 goto error;
5341 }
5342
5343 /* The session needs to be started at least once. */
5344 if (!session->has_been_started) {
5345 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5346 goto error;
5347 }
5348
5349 /* Use temporary output for the session. */
5350 if (*output->ctrl_url != '\0') {
5351 tmp_output = snapshot_output_alloc();
5352 if (!tmp_output) {
5353 cmd_ret = LTTNG_ERR_NOMEM;
5354 goto error;
5355 }
5356
5357 ret = snapshot_output_init(session,
5358 output->max_size,
5359 output->name,
5360 output->ctrl_url,
5361 output->data_url,
5362 session->consumer,
5363 tmp_output,
5364 nullptr);
5365 if (ret < 0) {
5366 if (ret == -ENOMEM) {
5367 cmd_ret = LTTNG_ERR_NOMEM;
5368 } else {
5369 cmd_ret = LTTNG_ERR_INVALID;
5370 }
5371 goto error;
5372 }
5373 /* Use the global session count for the temporary snapshot. */
5374 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
5375
5376 /* Use the global datetime */
5377 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
5378 cmd_ret = snapshot_record(session, tmp_output);
5379 if (cmd_ret != LTTNG_OK) {
5380 goto error;
5381 }
5382 snapshot_success = 1;
5383 } else {
5384 struct snapshot_output *sout;
5385 struct lttng_ht_iter iter;
5386
5387 lttng::urcu::read_lock_guard read_lock;
5388
5389 cds_lfht_for_each_entry (
5390 session->snapshot.output_ht->ht, &iter.iter, sout, node.node) {
5391 struct snapshot_output output_copy;
5392
5393 /*
5394 * Make a local copy of the output and override output
5395 * parameters with those provided as part of the
5396 * command.
5397 */
5398 memcpy(&output_copy, sout, sizeof(output_copy));
5399
5400 if (output->max_size != (uint64_t) -1ULL) {
5401 output_copy.max_size = output->max_size;
5402 }
5403
5404 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
5405 memcpy(output_copy.datetime, datetime, sizeof(datetime));
5406
5407 /* Use temporary name. */
5408 if (*output->name != '\0') {
5409 if (lttng_strncpy(output_copy.name,
5410 output->name,
5411 sizeof(output_copy.name))) {
5412 cmd_ret = LTTNG_ERR_INVALID;
5413 goto error;
5414 }
5415 }
5416
5417 cmd_ret = snapshot_record(session, &output_copy);
5418 if (cmd_ret != LTTNG_OK) {
5419 goto error;
5420 }
5421
5422 snapshot_success = 1;
5423 }
5424 }
5425
5426 if (snapshot_success) {
5427 session->snapshot.nb_snapshot++;
5428 } else {
5429 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
5430 }
5431
5432 error:
5433 if (tmp_output) {
5434 snapshot_output_destroy(tmp_output);
5435 }
5436
5437 return cmd_ret;
5438 }
5439
5440 /*
5441 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
5442 */
5443 int cmd_set_session_shm_path(struct ltt_session *session, const char *shm_path)
5444 {
5445 /* Safety net */
5446 LTTNG_ASSERT(session);
5447
5448 /*
5449 * Can only set shm path before session is started.
5450 */
5451 if (session->has_been_started) {
5452 return LTTNG_ERR_SESSION_STARTED;
5453 }
5454
5455 strncpy(session->shm_path, shm_path, sizeof(session->shm_path));
5456 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
5457
5458 return LTTNG_OK;
5459 }
5460
5461 /*
5462 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
5463 *
5464 * Ask the consumer to rotate the session output directory.
5465 * The session lock must be held.
5466 *
5467 * Returns LTTNG_OK on success or else a negative LTTng error code.
5468 */
5469 int cmd_rotate_session(struct ltt_session *session,
5470 struct lttng_rotate_session_return *rotate_return,
5471 bool quiet_rotation,
5472 enum lttng_trace_chunk_command_type command)
5473 {
5474 int ret;
5475 uint64_t ongoing_rotation_chunk_id;
5476 enum lttng_error_code cmd_ret = LTTNG_OK;
5477 struct lttng_trace_chunk *chunk_being_archived = nullptr;
5478 struct lttng_trace_chunk *new_trace_chunk = nullptr;
5479 enum lttng_trace_chunk_status chunk_status;
5480 bool failed_to_rotate = false;
5481 enum lttng_error_code rotation_fail_code = LTTNG_OK;
5482
5483 LTTNG_ASSERT(session);
5484
5485 if (!session->has_been_started) {
5486 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5487 goto end;
5488 }
5489
5490 /*
5491 * Explicit rotation is not supported for live sessions.
5492 * However, live sessions can perform a quiet rotation on
5493 * destroy.
5494 * Rotation is not supported for snapshot traces (no output).
5495 */
5496 if ((!quiet_rotation && session->live_timer) || !session->output_traces) {
5497 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5498 goto end;
5499 }
5500
5501 /* Unsupported feature in lttng-relayd before 2.11. */
5502 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
5503 (session->consumer->relay_major_version == 2 &&
5504 session->consumer->relay_minor_version < 11)) {
5505 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
5506 goto end;
5507 }
5508
5509 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
5510 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
5511 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
5512 goto end;
5513 }
5514
5515 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
5516 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
5517 session->name);
5518 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
5519 goto end;
5520 }
5521
5522 /*
5523 * After a stop, we only allow one rotation to occur, the other ones are
5524 * useless until a new start.
5525 */
5526 if (session->rotated_after_last_stop) {
5527 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
5528 session->name);
5529 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
5530 goto end;
5531 }
5532
5533 /*
5534 * After a stop followed by a clear, disallow following rotations a they would
5535 * generate empty chunks.
5536 */
5537 if (session->cleared_after_last_stop) {
5538 DBG("Session \"%s\" was already cleared after stop, refusing rotation",
5539 session->name);
5540 cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
5541 goto end;
5542 }
5543
5544 if (session->active) {
5545 new_trace_chunk =
5546 session_create_new_trace_chunk(session, nullptr, nullptr, nullptr);
5547 if (!new_trace_chunk) {
5548 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
5549 goto error;
5550 }
5551 }
5552
5553 /*
5554 * The current trace chunk becomes the chunk being archived.
5555 *
5556 * After this point, "chunk_being_archived" must absolutely
5557 * be closed on the consumer(s), otherwise it will never be
5558 * cleaned-up, which will result in a leak.
5559 */
5560 ret = session_set_trace_chunk(session, new_trace_chunk, &chunk_being_archived);
5561 if (ret) {
5562 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5563 goto error;
5564 }
5565
5566 if (session->kernel_session) {
5567 cmd_ret = kernel_rotate_session(session);
5568 if (cmd_ret != LTTNG_OK) {
5569 failed_to_rotate = true;
5570 rotation_fail_code = cmd_ret;
5571 }
5572 }
5573 if (session->ust_session) {
5574 cmd_ret = ust_app_rotate_session(session);
5575 if (cmd_ret != LTTNG_OK) {
5576 failed_to_rotate = true;
5577 rotation_fail_code = cmd_ret;
5578 }
5579 }
5580
5581 if (!session->active) {
5582 session->rotated_after_last_stop = true;
5583 }
5584
5585 if (!chunk_being_archived) {
5586 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
5587 session->name);
5588 if (failed_to_rotate) {
5589 cmd_ret = rotation_fail_code;
5590 goto error;
5591 }
5592 cmd_ret = LTTNG_OK;
5593 goto end;
5594 }
5595
5596 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5597 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived, &ongoing_rotation_chunk_id);
5598 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5599
5600 ret = session_close_trace_chunk(
5601 session, chunk_being_archived, command, session->last_chunk_path);
5602 if (ret) {
5603 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5604 goto error;
5605 }
5606
5607 if (failed_to_rotate) {
5608 cmd_ret = rotation_fail_code;
5609 goto error;
5610 }
5611
5612 session->quiet_rotation = quiet_rotation;
5613 ret = timer_session_rotation_pending_check_start(session, DEFAULT_ROTATE_PENDING_TIMER);
5614 if (ret) {
5615 cmd_ret = LTTNG_ERR_UNK;
5616 goto error;
5617 }
5618
5619 if (rotate_return) {
5620 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5621 }
5622
5623 session->chunk_being_archived = chunk_being_archived;
5624 chunk_being_archived = nullptr;
5625 if (!quiet_rotation) {
5626 ret = notification_thread_command_session_rotation_ongoing(
5627 the_notification_thread_handle, session->id, ongoing_rotation_chunk_id);
5628 if (ret != LTTNG_OK) {
5629 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5630 session->name);
5631 cmd_ret = (lttng_error_code) ret;
5632 }
5633 }
5634
5635 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5636 session->name,
5637 ongoing_rotation_chunk_id);
5638 end:
5639 lttng_trace_chunk_put(new_trace_chunk);
5640 lttng_trace_chunk_put(chunk_being_archived);
5641 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5642 return ret;
5643 error:
5644 if (session_reset_rotation_state(*session, LTTNG_ROTATION_STATE_ERROR)) {
5645 ERR("Failed to reset rotation state of session \"%s\"", session->name);
5646 }
5647 goto end;
5648 }
5649
5650 /*
5651 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5652 *
5653 * Check if the session has finished its rotation.
5654 *
5655 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5656 */
5657 int cmd_rotate_get_info(struct ltt_session *session,
5658 struct lttng_rotation_get_info_return *info_return,
5659 uint64_t rotation_id)
5660 {
5661 enum lttng_error_code cmd_ret = LTTNG_OK;
5662 enum lttng_rotation_state rotation_state;
5663
5664 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64,
5665 session->name,
5666 session->most_recent_chunk_id.value);
5667
5668 if (session->chunk_being_archived) {
5669 enum lttng_trace_chunk_status chunk_status;
5670 uint64_t chunk_id;
5671
5672 chunk_status = lttng_trace_chunk_get_id(session->chunk_being_archived, &chunk_id);
5673 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5674
5675 rotation_state = rotation_id == chunk_id ? LTTNG_ROTATION_STATE_ONGOING :
5676 LTTNG_ROTATION_STATE_EXPIRED;
5677 } else {
5678 if (session->last_archived_chunk_id.is_set &&
5679 rotation_id != session->last_archived_chunk_id.value) {
5680 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5681 } else {
5682 rotation_state = session->rotation_state;
5683 }
5684 }
5685
5686 switch (rotation_state) {
5687 case LTTNG_ROTATION_STATE_NO_ROTATION:
5688 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5689 session->name);
5690 goto end;
5691 case LTTNG_ROTATION_STATE_EXPIRED:
5692 DBG("Reporting that the rotation state of rotation id %" PRIu64
5693 " of session \"%s\" has expired",
5694 rotation_id,
5695 session->name);
5696 break;
5697 case LTTNG_ROTATION_STATE_ONGOING:
5698 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5699 rotation_id,
5700 session->name);
5701 break;
5702 case LTTNG_ROTATION_STATE_COMPLETED:
5703 {
5704 int fmt_ret;
5705 char *chunk_path;
5706 char *current_tracing_path_reply;
5707 size_t current_tracing_path_reply_len;
5708
5709 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5710 rotation_id,
5711 session->name);
5712
5713 switch (session_get_consumer_destination_type(session)) {
5714 case CONSUMER_DST_LOCAL:
5715 current_tracing_path_reply = info_return->location.local.absolute_path;
5716 current_tracing_path_reply_len =
5717 sizeof(info_return->location.local.absolute_path);
5718 info_return->location_type =
5719 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5720 fmt_ret = asprintf(&chunk_path,
5721 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5722 session_get_base_path(session),
5723 session->last_archived_chunk_name);
5724 if (fmt_ret == -1) {
5725 PERROR("Failed to format the path of the last archived trace chunk");
5726 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5727 cmd_ret = LTTNG_ERR_UNK;
5728 goto end;
5729 }
5730 break;
5731 case CONSUMER_DST_NET:
5732 {
5733 uint16_t ctrl_port, data_port;
5734
5735 current_tracing_path_reply = info_return->location.relay.relative_path;
5736 current_tracing_path_reply_len =
5737 sizeof(info_return->location.relay.relative_path);
5738 /* Currently the only supported relay protocol. */
5739 info_return->location.relay.protocol =
5740 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5741
5742 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5743 session_get_net_consumer_hostname(session),
5744 sizeof(info_return->location.relay.host));
5745 if (fmt_ret) {
5746 ERR("Failed to copy host name to rotate_get_info reply");
5747 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5748 cmd_ret = LTTNG_ERR_SET_URL;
5749 goto end;
5750 }
5751
5752 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5753 info_return->location.relay.ports.control = ctrl_port;
5754 info_return->location.relay.ports.data = data_port;
5755 info_return->location_type =
5756 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5757 chunk_path = strdup(session->last_chunk_path);
5758 if (!chunk_path) {
5759 ERR("Failed to allocate the path of the last archived trace chunk");
5760 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5761 cmd_ret = LTTNG_ERR_UNK;
5762 goto end;
5763 }
5764 break;
5765 }
5766 default:
5767 abort();
5768 }
5769
5770 fmt_ret = lttng_strncpy(
5771 current_tracing_path_reply, chunk_path, current_tracing_path_reply_len);
5772 free(chunk_path);
5773 if (fmt_ret) {
5774 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5775 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5776 cmd_ret = LTTNG_ERR_UNK;
5777 goto end;
5778 }
5779
5780 break;
5781 }
5782 case LTTNG_ROTATION_STATE_ERROR:
5783 DBG("Reporting that an error occurred during rotation %" PRIu64
5784 " of session \"%s\"",
5785 rotation_id,
5786 session->name);
5787 break;
5788 default:
5789 abort();
5790 }
5791
5792 cmd_ret = LTTNG_OK;
5793 end:
5794 info_return->status = (int32_t) rotation_state;
5795 return cmd_ret;
5796 }
5797
5798 /*
5799 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5800 *
5801 * Configure the automatic rotation parameters.
5802 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5803 * 'activate' to false means deactivate the rotation schedule and validate that
5804 * 'new_value' has the same value as the currently active value.
5805 *
5806 * Return LTTNG_OK on success or else a positive LTTNG_ERR code.
5807 */
5808 int cmd_rotation_set_schedule(struct ltt_session *session,
5809 bool activate,
5810 enum lttng_rotation_schedule_type schedule_type,
5811 uint64_t new_value)
5812 {
5813 int ret;
5814 uint64_t *parameter_value;
5815
5816 LTTNG_ASSERT(session);
5817
5818 DBG("Cmd rotate set schedule session %s", session->name);
5819
5820 if (session->live_timer || !session->output_traces) {
5821 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5822 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5823 goto end;
5824 }
5825
5826 switch (schedule_type) {
5827 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5828 parameter_value = &session->rotate_size;
5829 break;
5830 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5831 parameter_value = &session->rotate_timer_period;
5832 if (new_value >= UINT_MAX) {
5833 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64
5834 " > %u (UINT_MAX)",
5835 new_value,
5836 UINT_MAX);
5837 ret = LTTNG_ERR_INVALID;
5838 goto end;
5839 }
5840 break;
5841 default:
5842 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5843 ret = LTTNG_ERR_INVALID;
5844 goto end;
5845 }
5846
5847 /* Improper use of the API. */
5848 if (new_value == -1ULL) {
5849 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5850 ret = LTTNG_ERR_INVALID;
5851 goto end;
5852 }
5853
5854 /*
5855 * As indicated in struct ltt_session's comments, a value of == 0 means
5856 * this schedule rotation type is not in use.
5857 *
5858 * Reject the command if we were asked to activate a schedule that was
5859 * already active.
5860 */
5861 if (activate && *parameter_value != 0) {
5862 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5863 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5864 goto end;
5865 }
5866
5867 /*
5868 * Reject the command if we were asked to deactivate a schedule that was
5869 * not active.
5870 */
5871 if (!activate && *parameter_value == 0) {
5872 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5873 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5874 goto end;
5875 }
5876
5877 /*
5878 * Reject the command if we were asked to deactivate a schedule that
5879 * doesn't exist.
5880 */
5881 if (!activate && *parameter_value != new_value) {
5882 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5883 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5884 goto end;
5885 }
5886
5887 *parameter_value = activate ? new_value : 0;
5888
5889 switch (schedule_type) {
5890 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5891 if (activate && session->active) {
5892 /*
5893 * Only start the timer if the session is active,
5894 * otherwise it will be started when the session starts.
5895 */
5896 ret = timer_session_rotation_schedule_timer_start(session, new_value);
5897 if (ret) {
5898 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5899 ret = LTTNG_ERR_UNK;
5900 goto end;
5901 }
5902 } else {
5903 ret = timer_session_rotation_schedule_timer_stop(session);
5904 if (ret) {
5905 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5906 ret = LTTNG_ERR_UNK;
5907 goto end;
5908 }
5909 }
5910 break;
5911 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5912 if (activate) {
5913 try {
5914 the_rotation_thread_handle->subscribe_session_consumed_size_rotation(
5915 *session, new_value);
5916 } catch (const std::exception& e) {
5917 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command: %s",
5918 e.what());
5919 ret = LTTNG_ERR_UNK;
5920 goto end;
5921 }
5922 } else {
5923 try {
5924 the_rotation_thread_handle
5925 ->unsubscribe_session_consumed_size_rotation(*session);
5926 } catch (const std::exception& e) {
5927 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command: %s",
5928 e.what());
5929 ret = LTTNG_ERR_UNK;
5930 goto end;
5931 }
5932 }
5933 break;
5934 default:
5935 /* Would have been caught before. */
5936 abort();
5937 }
5938
5939 ret = LTTNG_OK;
5940
5941 goto end;
5942
5943 end:
5944 return ret;
5945 }
5946
5947 /* Wait for a given path to be removed before continuing. */
5948 static enum lttng_error_code wait_on_path(void *path_data)
5949 {
5950 const char *shm_path = (const char *) path_data;
5951
5952 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
5953 shm_path);
5954 while (true) {
5955 int ret;
5956 struct stat st;
5957
5958 ret = stat(shm_path, &st);
5959 if (ret) {
5960 if (errno != ENOENT) {
5961 PERROR("stat() returned an error while checking for the existence of the shm path");
5962 } else {
5963 DBG("shm path no longer exists, completing the destruction of session");
5964 }
5965 break;
5966 } else {
5967 if (!S_ISDIR(st.st_mode)) {
5968 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5969 shm_path);
5970 break;
5971 }
5972 }
5973 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5974 }
5975 return LTTNG_OK;
5976 }
5977
5978 /*
5979 * Returns a pointer to a handler to run on completion of a command.
5980 * Returns NULL if no handler has to be run for the last command executed.
5981 */
5982 const struct cmd_completion_handler *cmd_pop_completion_handler()
5983 {
5984 struct cmd_completion_handler *handler = current_completion_handler;
5985
5986 current_completion_handler = nullptr;
5987 return handler;
5988 }
5989
5990 /*
5991 * Init command subsystem.
5992 */
5993 void cmd_init()
5994 {
5995 /*
5996 * Set network sequence index to 1 for streams to match a relayd
5997 * socket on the consumer side.
5998 */
5999 pthread_mutex_lock(&relayd_net_seq_idx_lock);
6000 relayd_net_seq_idx = 1;
6001 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
6002
6003 DBG("Command subsystem initialized");
6004 }
LTTng 2.0 tools and control repository
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