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Fix: rotation: hang on destroy when using scheduled rotation based on timer
[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
10 #define _LGPL_SOURCE
11 #include <algorithm>
12 #include <inttypes.h>
13 #include <stdio.h>
14 #include <sys/stat.h>
15 #include <urcu/list.h>
16 #include <urcu/uatomic.h>
17
18 #include <common/buffer-view.h>
19 #include <common/common.h>
20 #include <common/compat/string.h>
21 #include <common/defaults.h>
22 #include <common/dynamic-buffer.h>
23 #include <common/kernel-ctl/kernel-ctl.h>
24 #include <common/relayd/relayd.h>
25 #include <common/sessiond-comm/sessiond-comm.h>
26 #include <common/string-utils/string-utils.h>
27 #include <common/trace-chunk.h>
28 #include <common/utils.h>
29
30 #include <lttng/action/action.h>
31 #include <lttng/action/action-internal.h>
32 #include <lttng/channel-internal.h>
33 #include <lttng/channel.h>
34 #include <lttng/condition/condition.h>
35 #include <lttng/error-query-internal.h>
36 #include <lttng/event-internal.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/rotate-internal.h>
39 #include <lttng/session-descriptor-internal.h>
40 #include <lttng/session-internal.h>
41 #include <lttng/trigger/trigger-internal.h>
42 #include <lttng/userspace-probe-internal.h>
43
44 #include "agent-thread.h"
45 #include "agent.h"
46 #include "buffer-registry.h"
47 #include "channel.h"
48 #include "cmd.h"
49 #include "consumer.h"
50 #include "event-notifier-error-accounting.h"
51 #include "event.h"
52 #include "health-sessiond.h"
53 #include "kernel-consumer.h"
54 #include "kernel.h"
55 #include "lttng-sessiond.h"
56 #include "lttng-syscall.h"
57 #include "notification-thread-commands.h"
58 #include "notification-thread.h"
59 #include "rotate.h"
60 #include "rotation-thread.h"
61 #include "session.h"
62 #include "timer.h"
63 #include "tracker.h"
64 #include "utils.h"
65
66 /* Sleep for 100ms between each check for the shm path's deletion. */
67 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
68
69 struct cmd_destroy_session_reply_context {
70 int reply_sock_fd;
71 bool implicit_rotation_on_destroy;
72 /*
73 * Indicates whether or not an error occurred while launching the
74 * destruction of a session.
75 */
76 enum lttng_error_code destruction_status;
77 };
78
79 static enum lttng_error_code wait_on_path(void *path);
80
81 /*
82 * Command completion handler that is used by the destroy command
83 * when a session that has a non-default shm_path is being destroyed.
84 *
85 * See comment in cmd_destroy_session() for the rationale.
86 */
87 static struct destroy_completion_handler {
88 struct cmd_completion_handler handler;
89 char shm_path[member_sizeof(struct ltt_session, shm_path)];
90 } destroy_completion_handler = {
91 .handler = {
92 .run = wait_on_path,
93 .data = destroy_completion_handler.shm_path
94 },
95 .shm_path = { 0 },
96 };
97
98 static struct cmd_completion_handler *current_completion_handler;
99
100 /*
101 * Used to keep a unique index for each relayd socket created where this value
102 * is associated with streams on the consumer so it can match the right relayd
103 * to send to. It must be accessed with the relayd_net_seq_idx_lock
104 * held.
105 */
106 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
107 static uint64_t relayd_net_seq_idx;
108
109 static int validate_ust_event_name(const char *);
110 static int cmd_enable_event_internal(struct ltt_session *session,
111 const struct lttng_domain *domain,
112 char *channel_name, struct lttng_event *event,
113 char *filter_expression,
114 struct lttng_bytecode *filter,
115 struct lttng_event_exclusion *exclusion,
116 int wpipe);
117 static int cmd_enable_channel_internal(struct ltt_session *session,
118 const struct lttng_domain *domain,
119 const struct lttng_channel *_attr,
120 int wpipe);
121
122 /*
123 * Create a session path used by list_lttng_sessions for the case that the
124 * session consumer is on the network.
125 */
126 static int build_network_session_path(char *dst, size_t size,
127 struct ltt_session *session)
128 {
129 int ret, kdata_port, udata_port;
130 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
131 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
132
133 LTTNG_ASSERT(session);
134 LTTNG_ASSERT(dst);
135
136 memset(tmp_urls, 0, sizeof(tmp_urls));
137 memset(tmp_uurl, 0, sizeof(tmp_uurl));
138
139 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
140
141 if (session->kernel_session && session->kernel_session->consumer) {
142 kuri = &session->kernel_session->consumer->dst.net.control;
143 kdata_port = session->kernel_session->consumer->dst.net.data.port;
144 }
145
146 if (session->ust_session && session->ust_session->consumer) {
147 uuri = &session->ust_session->consumer->dst.net.control;
148 udata_port = session->ust_session->consumer->dst.net.data.port;
149 }
150
151 if (uuri == NULL && kuri == NULL) {
152 uri = &session->consumer->dst.net.control;
153 kdata_port = session->consumer->dst.net.data.port;
154 } else if (kuri && uuri) {
155 ret = uri_compare(kuri, uuri);
156 if (ret) {
157 /* Not Equal */
158 uri = kuri;
159 /* Build uuri URL string */
160 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
161 if (ret < 0) {
162 goto error;
163 }
164 } else {
165 uri = kuri;
166 }
167 } else if (kuri && uuri == NULL) {
168 uri = kuri;
169 } else if (uuri && kuri == NULL) {
170 uri = uuri;
171 }
172
173 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
174 if (ret < 0) {
175 goto error;
176 }
177
178 /*
179 * Do we have a UST url set. If yes, this means we have both kernel and UST
180 * to print.
181 */
182 if (*tmp_uurl != '\0') {
183 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
184 tmp_urls, kdata_port, tmp_uurl, udata_port);
185 } else {
186 int dport;
187 if (kuri || (!kuri && !uuri)) {
188 dport = kdata_port;
189 } else {
190 /* No kernel URI, use the UST port. */
191 dport = udata_port;
192 }
193 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
194 }
195
196 error:
197 return ret;
198 }
199
200 /*
201 * Get run-time attributes if the session has been started (discarded events,
202 * lost packets).
203 */
204 static int get_kernel_runtime_stats(struct ltt_session *session,
205 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
206 uint64_t *lost_packets)
207 {
208 int ret;
209
210 if (!session->has_been_started) {
211 ret = 0;
212 *discarded_events = 0;
213 *lost_packets = 0;
214 goto end;
215 }
216
217 ret = consumer_get_discarded_events(session->id, kchan->key,
218 session->kernel_session->consumer,
219 discarded_events);
220 if (ret < 0) {
221 goto end;
222 }
223
224 ret = consumer_get_lost_packets(session->id, kchan->key,
225 session->kernel_session->consumer,
226 lost_packets);
227 if (ret < 0) {
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Get run-time attributes if the session has been started (discarded events,
237 * lost packets).
238 */
239 static int get_ust_runtime_stats(struct ltt_session *session,
240 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
241 uint64_t *lost_packets)
242 {
243 int ret;
244 struct ltt_ust_session *usess;
245
246 if (!discarded_events || !lost_packets) {
247 ret = -1;
248 goto end;
249 }
250
251 usess = session->ust_session;
252 LTTNG_ASSERT(discarded_events);
253 LTTNG_ASSERT(lost_packets);
254
255 if (!usess || !session->has_been_started) {
256 *discarded_events = 0;
257 *lost_packets = 0;
258 ret = 0;
259 goto end;
260 }
261
262 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
263 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
264 &usess->buffer_reg_uid_list,
265 usess->consumer, uchan->id,
266 uchan->attr.overwrite,
267 discarded_events,
268 lost_packets);
269 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
270 ret = ust_app_pid_get_channel_runtime_stats(usess,
271 uchan, usess->consumer,
272 uchan->attr.overwrite,
273 discarded_events,
274 lost_packets);
275 if (ret < 0) {
276 goto end;
277 }
278 *discarded_events += uchan->per_pid_closed_app_discarded;
279 *lost_packets += uchan->per_pid_closed_app_lost;
280 } else {
281 ERR("Unsupported buffer type");
282 abort();
283 ret = -1;
284 goto end;
285 }
286
287 end:
288 return ret;
289 }
290
291 /*
292 * Create a list of agent domain events.
293 *
294 * Return number of events in list on success or else a negative value.
295 */
296 static enum lttng_error_code list_lttng_agent_events(
297 struct agent *agt, struct lttng_payload *reply_payload,
298 unsigned int *nb_events)
299 {
300 enum lttng_error_code ret_code;
301 int ret = 0;
302 unsigned int local_nb_events = 0;
303 struct agent_event *event;
304 struct lttng_ht_iter iter;
305 unsigned long agent_event_count;
306
307 assert(agt);
308 assert(reply_payload);
309
310 DBG3("Listing agent events");
311
312 rcu_read_lock();
313 agent_event_count = lttng_ht_get_count(agt->events);
314 if (agent_event_count == 0) {
315 /* Early exit. */
316 goto end;
317 }
318
319 if (agent_event_count > UINT_MAX) {
320 ret_code = LTTNG_ERR_OVERFLOW;
321 goto error;
322 }
323
324 local_nb_events = (unsigned int) agent_event_count;
325
326 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
327 struct lttng_event *tmp_event = lttng_event_create();
328
329 if (!tmp_event) {
330 ret_code = LTTNG_ERR_NOMEM;
331 goto error;
332 }
333
334 if (lttng_strncpy(tmp_event->name, event->name, sizeof(tmp_event->name))) {
335 lttng_event_destroy(tmp_event);
336 ret_code = LTTNG_ERR_FATAL;
337 goto error;
338 }
339
340 tmp_event->name[sizeof(tmp_event->name) - 1] = '\0';
341 tmp_event->enabled = !!event->enabled_count;
342 tmp_event->loglevel = event->loglevel_value;
343 tmp_event->loglevel_type = event->loglevel_type;
344
345 ret = lttng_event_serialize(tmp_event, 0, NULL,
346 event->filter_expression, 0, NULL, reply_payload);
347 lttng_event_destroy(tmp_event);
348 if (ret) {
349 ret_code = LTTNG_ERR_FATAL;
350 goto error;
351 }
352 }
353
354 end:
355 ret_code = LTTNG_OK;
356 *nb_events = local_nb_events;
357 error:
358 rcu_read_unlock();
359 return ret_code;
360 }
361
362 /*
363 * Create a list of ust global domain events.
364 */
365 static enum lttng_error_code list_lttng_ust_global_events(char *channel_name,
366 struct ltt_ust_domain_global *ust_global,
367 struct lttng_payload *reply_payload,
368 unsigned int *nb_events)
369 {
370 enum lttng_error_code ret_code;
371 int ret;
372 struct lttng_ht_iter iter;
373 struct lttng_ht_node_str *node;
374 struct ltt_ust_channel *uchan;
375 struct ltt_ust_event *uevent;
376 unsigned long channel_event_count;
377 unsigned int local_nb_events = 0;
378
379 assert(reply_payload);
380 assert(nb_events);
381
382 DBG("Listing UST global events for channel %s", channel_name);
383
384 rcu_read_lock();
385
386 lttng_ht_lookup(ust_global->channels, (void *) channel_name, &iter);
387 node = lttng_ht_iter_get_node_str(&iter);
388 if (node == NULL) {
389 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
390 goto error;
391 }
392
393 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
394
395 channel_event_count = lttng_ht_get_count(uchan->events);
396 if (channel_event_count == 0) {
397 /* Early exit. */
398 ret_code = LTTNG_OK;
399 goto end;
400 }
401
402 if (channel_event_count > UINT_MAX) {
403 ret_code = LTTNG_ERR_OVERFLOW;
404 goto error;
405 }
406
407 local_nb_events = (unsigned int) channel_event_count;
408
409 DBG3("Listing UST global %d events", *nb_events);
410
411 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
412 struct lttng_event *tmp_event = NULL;
413
414 if (uevent->internal) {
415 /* This event should remain hidden from clients */
416 local_nb_events--;
417 continue;
418 }
419
420 tmp_event = lttng_event_create();
421 if (!tmp_event) {
422 ret_code = LTTNG_ERR_NOMEM;
423 goto error;
424 }
425
426 if (lttng_strncpy(tmp_event->name, uevent->attr.name,
427 LTTNG_SYMBOL_NAME_LEN)) {
428 ret_code = LTTNG_ERR_FATAL;
429 lttng_event_destroy(tmp_event);
430 goto error;
431 }
432
433 tmp_event->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
434 tmp_event->enabled = uevent->enabled;
435
436 switch (uevent->attr.instrumentation) {
437 case LTTNG_UST_ABI_TRACEPOINT:
438 tmp_event->type = LTTNG_EVENT_TRACEPOINT;
439 break;
440 case LTTNG_UST_ABI_PROBE:
441 tmp_event->type = LTTNG_EVENT_PROBE;
442 break;
443 case LTTNG_UST_ABI_FUNCTION:
444 tmp_event->type = LTTNG_EVENT_FUNCTION;
445 break;
446 }
447
448 tmp_event->loglevel = uevent->attr.loglevel;
449 switch (uevent->attr.loglevel_type) {
450 case LTTNG_UST_ABI_LOGLEVEL_ALL:
451 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
452 break;
453 case LTTNG_UST_ABI_LOGLEVEL_RANGE:
454 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
455 break;
456 case LTTNG_UST_ABI_LOGLEVEL_SINGLE:
457 tmp_event->loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
458 break;
459 }
460 if (uevent->filter) {
461 tmp_event->filter = 1;
462 }
463 if (uevent->exclusion) {
464 tmp_event->exclusion = 1;
465 }
466
467 /*
468 * We do not care about the filter bytecode and the fd from the
469 * userspace_probe_location.
470 */
471 ret = lttng_event_serialize(tmp_event, uevent->exclusion ? uevent->exclusion->count : 0,
472 uevent->exclusion ? (char **) uevent->exclusion ->names : NULL,
473 uevent->filter_expression, 0, NULL, reply_payload);
474 lttng_event_destroy(tmp_event);
475 if (ret) {
476 ret_code = LTTNG_ERR_FATAL;
477 goto error;
478 }
479 }
480
481 end:
482 /* nb_events is already set at this point. */
483 ret_code = LTTNG_OK;
484 *nb_events = local_nb_events;
485 error:
486 rcu_read_unlock();
487 return ret_code;
488 }
489
490 /*
491 * Fill lttng_event array of all kernel events in the channel.
492 */
493 static enum lttng_error_code list_lttng_kernel_events(char *channel_name,
494 struct ltt_kernel_session *kernel_session,
495 struct lttng_payload *reply_payload,
496 unsigned int *nb_events)
497 {
498 enum lttng_error_code ret_code;
499 int ret;
500 struct ltt_kernel_event *event;
501 struct ltt_kernel_channel *kchan;
502
503 assert(reply_payload);
504
505 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
506 if (kchan == NULL) {
507 ret_code = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
508 goto end;
509 }
510
511 *nb_events = kchan->event_count;
512
513 DBG("Listing events for channel %s", kchan->channel->name);
514
515 if (*nb_events == 0) {
516 ret_code = LTTNG_OK;
517 goto end;
518 }
519
520 /* Kernel channels */
521 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
522 struct lttng_event *tmp_event = lttng_event_create();
523
524 if (!tmp_event) {
525 ret_code = LTTNG_ERR_NOMEM;
526 goto end;
527 }
528
529 if (lttng_strncpy(tmp_event->name, event->event->name, LTTNG_SYMBOL_NAME_LEN)) {
530 lttng_event_destroy(tmp_event);
531 ret_code = LTTNG_ERR_FATAL;
532 goto end;
533
534 }
535
536 tmp_event->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
537 tmp_event->enabled = event->enabled;
538 tmp_event->filter = (unsigned char) !!event->filter_expression;
539
540 switch (event->event->instrumentation) {
541 case LTTNG_KERNEL_ABI_TRACEPOINT:
542 tmp_event->type = LTTNG_EVENT_TRACEPOINT;
543 break;
544 case LTTNG_KERNEL_ABI_KRETPROBE:
545 tmp_event->type = LTTNG_EVENT_FUNCTION;
546 memcpy(&tmp_event->attr.probe, &event->event->u.kprobe,
547 sizeof(struct lttng_kernel_abi_kprobe));
548 break;
549 case LTTNG_KERNEL_ABI_KPROBE:
550 tmp_event->type = LTTNG_EVENT_PROBE;
551 memcpy(&tmp_event->attr.probe, &event->event->u.kprobe,
552 sizeof(struct lttng_kernel_abi_kprobe));
553 break;
554 case LTTNG_KERNEL_ABI_UPROBE:
555 tmp_event->type = LTTNG_EVENT_USERSPACE_PROBE;
556 break;
557 case LTTNG_KERNEL_ABI_FUNCTION:
558 tmp_event->type = LTTNG_EVENT_FUNCTION;
559 memcpy(&(tmp_event->attr.ftrace), &event->event->u.ftrace,
560 sizeof(struct lttng_kernel_abi_function));
561 break;
562 case LTTNG_KERNEL_ABI_NOOP:
563 tmp_event->type = LTTNG_EVENT_NOOP;
564 break;
565 case LTTNG_KERNEL_ABI_SYSCALL:
566 tmp_event->type = LTTNG_EVENT_SYSCALL;
567 break;
568 case LTTNG_KERNEL_ABI_ALL:
569 /* fall-through. */
570 default:
571 abort();
572 break;
573 }
574
575 if (event->userspace_probe_location) {
576 struct lttng_userspace_probe_location *location_copy =
577 lttng_userspace_probe_location_copy(
578 event->userspace_probe_location);
579
580 if (!location_copy) {
581 lttng_event_destroy(tmp_event);
582 ret_code = LTTNG_ERR_NOMEM;
583 goto end;
584 }
585
586 ret = lttng_event_set_userspace_probe_location(
587 tmp_event, location_copy);
588 if (ret) {
589 lttng_event_destroy(tmp_event);
590 lttng_userspace_probe_location_destroy(
591 location_copy);
592 ret_code = LTTNG_ERR_INVALID;
593 goto end;
594 }
595 }
596
597 ret = lttng_event_serialize(tmp_event, 0, NULL,
598 event->filter_expression, 0, NULL, reply_payload);
599 lttng_event_destroy(tmp_event);
600 if (ret) {
601 ret_code = LTTNG_ERR_FATAL;
602 goto end;
603 }
604 }
605
606 ret_code = LTTNG_OK;
607 end:
608 return ret_code;
609 }
610
611 /*
612 * Add URI so the consumer output object. Set the correct path depending on the
613 * domain adding the default trace directory.
614 */
615 static enum lttng_error_code add_uri_to_consumer(
616 const struct ltt_session *session,
617 struct consumer_output *consumer,
618 struct lttng_uri *uri, enum lttng_domain_type domain)
619 {
620 int ret;
621 enum lttng_error_code ret_code = LTTNG_OK;
622
623 LTTNG_ASSERT(uri);
624
625 if (consumer == NULL) {
626 DBG("No consumer detected. Don't add URI. Stopping.");
627 ret_code = LTTNG_ERR_NO_CONSUMER;
628 goto error;
629 }
630
631 switch (domain) {
632 case LTTNG_DOMAIN_KERNEL:
633 ret = lttng_strncpy(consumer->domain_subdir,
634 DEFAULT_KERNEL_TRACE_DIR,
635 sizeof(consumer->domain_subdir));
636 break;
637 case LTTNG_DOMAIN_UST:
638 ret = lttng_strncpy(consumer->domain_subdir,
639 DEFAULT_UST_TRACE_DIR,
640 sizeof(consumer->domain_subdir));
641 break;
642 default:
643 /*
644 * This case is possible is we try to add the URI to the global
645 * tracing session consumer object which in this case there is
646 * no subdir.
647 */
648 memset(consumer->domain_subdir, 0,
649 sizeof(consumer->domain_subdir));
650 ret = 0;
651 }
652 if (ret) {
653 ERR("Failed to initialize consumer output domain subdirectory");
654 ret_code = LTTNG_ERR_FATAL;
655 goto error;
656 }
657
658 switch (uri->dtype) {
659 case LTTNG_DST_IPV4:
660 case LTTNG_DST_IPV6:
661 DBG2("Setting network URI to consumer");
662
663 if (consumer->type == CONSUMER_DST_NET) {
664 if ((uri->stype == LTTNG_STREAM_CONTROL &&
665 consumer->dst.net.control_isset) ||
666 (uri->stype == LTTNG_STREAM_DATA &&
667 consumer->dst.net.data_isset)) {
668 ret_code = LTTNG_ERR_URL_EXIST;
669 goto error;
670 }
671 } else {
672 memset(&consumer->dst, 0, sizeof(consumer->dst));
673 }
674
675 /* Set URI into consumer output object */
676 ret = consumer_set_network_uri(session, consumer, uri);
677 if (ret < 0) {
678 ret_code = (lttng_error_code) -ret;
679 goto error;
680 } else if (ret == 1) {
681 /*
682 * URI was the same in the consumer so we do not append the subdir
683 * again so to not duplicate output dir.
684 */
685 ret_code = LTTNG_OK;
686 goto error;
687 }
688 break;
689 case LTTNG_DST_PATH:
690 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
691 ret_code = LTTNG_ERR_INVALID;
692 goto error;
693 }
694 DBG2("Setting trace directory path from URI to %s",
695 uri->dst.path);
696 memset(&consumer->dst, 0, sizeof(consumer->dst));
697
698 ret = lttng_strncpy(consumer->dst.session_root_path,
699 uri->dst.path,
700 sizeof(consumer->dst.session_root_path));
701 if (ret) {
702 ret_code = LTTNG_ERR_FATAL;
703 goto error;
704 }
705 consumer->type = CONSUMER_DST_LOCAL;
706 break;
707 }
708
709 ret_code = LTTNG_OK;
710 error:
711 return ret_code;
712 }
713
714 /*
715 * Init tracing by creating trace directory and sending fds kernel consumer.
716 */
717 static int init_kernel_tracing(struct ltt_kernel_session *session)
718 {
719 int ret = 0;
720 struct lttng_ht_iter iter;
721 struct consumer_socket *socket;
722
723 LTTNG_ASSERT(session);
724
725 rcu_read_lock();
726
727 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
728 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
729 socket, node.node) {
730 pthread_mutex_lock(socket->lock);
731 ret = kernel_consumer_send_session(socket, session);
732 pthread_mutex_unlock(socket->lock);
733 if (ret < 0) {
734 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
735 goto error;
736 }
737 }
738 }
739
740 error:
741 rcu_read_unlock();
742 return ret;
743 }
744
745 /*
746 * Create a socket to the relayd using the URI.
747 *
748 * On success, the relayd_sock pointer is set to the created socket.
749 * Else, it remains untouched and an LTTng error code is returned.
750 */
751 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
752 struct lttcomm_relayd_sock **relayd_sock,
753 struct consumer_output *consumer)
754 {
755 int ret;
756 enum lttng_error_code status = LTTNG_OK;
757 struct lttcomm_relayd_sock *rsock;
758
759 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
760 RELAYD_VERSION_COMM_MINOR);
761 if (!rsock) {
762 status = LTTNG_ERR_FATAL;
763 goto error;
764 }
765
766 /*
767 * Connect to relayd so we can proceed with a session creation. This call
768 * can possibly block for an arbitrary amount of time to set the health
769 * state to be in poll execution.
770 */
771 health_poll_entry();
772 ret = relayd_connect(rsock);
773 health_poll_exit();
774 if (ret < 0) {
775 ERR("Unable to reach lttng-relayd");
776 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
777 goto free_sock;
778 }
779
780 /* Create socket for control stream. */
781 if (uri->stype == LTTNG_STREAM_CONTROL) {
782 uint64_t result_flags;
783
784 DBG3("Creating relayd stream socket from URI");
785
786 /* Check relayd version */
787 ret = relayd_version_check(rsock);
788 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
789 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
790 goto close_sock;
791 } else if (ret < 0) {
792 ERR("Unable to reach lttng-relayd");
793 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
794 goto close_sock;
795 }
796 consumer->relay_major_version = rsock->major;
797 consumer->relay_minor_version = rsock->minor;
798 ret = relayd_get_configuration(rsock, 0,
799 &result_flags);
800 if (ret < 0) {
801 ERR("Unable to get relayd configuration");
802 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
803 goto close_sock;
804 }
805 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
806 consumer->relay_allows_clear = true;
807 }
808 } else if (uri->stype == LTTNG_STREAM_DATA) {
809 DBG3("Creating relayd data socket from URI");
810 } else {
811 /* Command is not valid */
812 ERR("Relayd invalid stream type: %d", uri->stype);
813 status = LTTNG_ERR_INVALID;
814 goto close_sock;
815 }
816
817 *relayd_sock = rsock;
818
819 return status;
820
821 close_sock:
822 /* The returned value is not useful since we are on an error path. */
823 (void) relayd_close(rsock);
824 free_sock:
825 free(rsock);
826 error:
827 return status;
828 }
829
830 /*
831 * Connect to the relayd using URI and send the socket to the right consumer.
832 *
833 * The consumer socket lock must be held by the caller.
834 *
835 * Returns LTTNG_OK on success or an LTTng error code on failure.
836 */
837 static enum lttng_error_code send_consumer_relayd_socket(
838 unsigned int session_id,
839 struct lttng_uri *relayd_uri,
840 struct consumer_output *consumer,
841 struct consumer_socket *consumer_sock,
842 const char *session_name, const char *hostname,
843 const char *base_path, int session_live_timer,
844 const uint64_t *current_chunk_id,
845 time_t session_creation_time,
846 bool session_name_contains_creation_time)
847 {
848 int ret;
849 struct lttcomm_relayd_sock *rsock = NULL;
850 enum lttng_error_code status;
851
852 /* Connect to relayd and make version check if uri is the control. */
853 status = create_connect_relayd(relayd_uri, &rsock, consumer);
854 if (status != LTTNG_OK) {
855 goto relayd_comm_error;
856 }
857 LTTNG_ASSERT(rsock);
858
859 /* Set the network sequence index if not set. */
860 if (consumer->net_seq_index == (uint64_t) -1ULL) {
861 pthread_mutex_lock(&relayd_net_seq_idx_lock);
862 /*
863 * Increment net_seq_idx because we are about to transfer the
864 * new relayd socket to the consumer.
865 * Assign unique key so the consumer can match streams.
866 */
867 consumer->net_seq_index = ++relayd_net_seq_idx;
868 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
869 }
870
871 /* Send relayd socket to consumer. */
872 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
873 relayd_uri->stype, session_id,
874 session_name, hostname, base_path,
875 session_live_timer, current_chunk_id,
876 session_creation_time, session_name_contains_creation_time);
877 if (ret < 0) {
878 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
879 goto close_sock;
880 }
881
882 /* Flag that the corresponding socket was sent. */
883 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
884 consumer_sock->control_sock_sent = 1;
885 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
886 consumer_sock->data_sock_sent = 1;
887 }
888
889 /*
890 * Close socket which was dup on the consumer side. The session daemon does
891 * NOT keep track of the relayd socket(s) once transfer to the consumer.
892 */
893
894 close_sock:
895 if (status != LTTNG_OK) {
896 /*
897 * The consumer output for this session should not be used anymore
898 * since the relayd connection failed thus making any tracing or/and
899 * streaming not usable.
900 */
901 consumer->enabled = 0;
902 }
903 (void) relayd_close(rsock);
904 free(rsock);
905
906 relayd_comm_error:
907 return status;
908 }
909
910 /*
911 * Send both relayd sockets to a specific consumer and domain. This is a
912 * helper function to facilitate sending the information to the consumer for a
913 * session.
914 *
915 * The consumer socket lock must be held by the caller.
916 *
917 * Returns LTTNG_OK, or an LTTng error code on failure.
918 */
919 static enum lttng_error_code send_consumer_relayd_sockets(
920 enum lttng_domain_type domain,
921 unsigned int session_id, struct consumer_output *consumer,
922 struct consumer_socket *sock, const char *session_name,
923 const char *hostname, const char *base_path, int session_live_timer,
924 const uint64_t *current_chunk_id, time_t session_creation_time,
925 bool session_name_contains_creation_time)
926 {
927 enum lttng_error_code status = LTTNG_OK;
928
929 LTTNG_ASSERT(consumer);
930 LTTNG_ASSERT(sock);
931
932 /* Sending control relayd socket. */
933 if (!sock->control_sock_sent) {
934 status = send_consumer_relayd_socket(session_id,
935 &consumer->dst.net.control, consumer, sock,
936 session_name, hostname, base_path, session_live_timer,
937 current_chunk_id, session_creation_time,
938 session_name_contains_creation_time);
939 if (status != LTTNG_OK) {
940 goto error;
941 }
942 }
943
944 /* Sending data relayd socket. */
945 if (!sock->data_sock_sent) {
946 status = send_consumer_relayd_socket(session_id,
947 &consumer->dst.net.data, consumer, sock,
948 session_name, hostname, base_path, session_live_timer,
949 current_chunk_id, session_creation_time,
950 session_name_contains_creation_time);
951 if (status != LTTNG_OK) {
952 goto error;
953 }
954 }
955
956 error:
957 return status;
958 }
959
960 /*
961 * Setup relayd connections for a tracing session. First creates the socket to
962 * the relayd and send them to the right domain consumer. Consumer type MUST be
963 * network.
964 */
965 int cmd_setup_relayd(struct ltt_session *session)
966 {
967 int ret = LTTNG_OK;
968 struct ltt_ust_session *usess;
969 struct ltt_kernel_session *ksess;
970 struct consumer_socket *socket;
971 struct lttng_ht_iter iter;
972 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
973
974 LTTNG_ASSERT(session);
975
976 usess = session->ust_session;
977 ksess = session->kernel_session;
978
979 DBG("Setting relayd for session %s", session->name);
980
981 rcu_read_lock();
982 if (session->current_trace_chunk) {
983 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
984 session->current_trace_chunk, &current_chunk_id.value);
985
986 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
987 current_chunk_id.is_set = true;
988 } else {
989 ERR("Failed to get current trace chunk id");
990 ret = LTTNG_ERR_UNK;
991 goto error;
992 }
993 }
994
995 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
996 && usess->consumer->enabled) {
997 /* For each consumer socket, send relayd sockets */
998 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
999 socket, node.node) {
1000 pthread_mutex_lock(socket->lock);
1001 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1002 usess->consumer, socket,
1003 session->name, session->hostname,
1004 session->base_path,
1005 session->live_timer,
1006 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1007 session->creation_time,
1008 session->name_contains_creation_time);
1009 pthread_mutex_unlock(socket->lock);
1010 if (ret != LTTNG_OK) {
1011 goto error;
1012 }
1013 /* Session is now ready for network streaming. */
1014 session->net_handle = 1;
1015 }
1016 session->consumer->relay_major_version =
1017 usess->consumer->relay_major_version;
1018 session->consumer->relay_minor_version =
1019 usess->consumer->relay_minor_version;
1020 session->consumer->relay_allows_clear =
1021 usess->consumer->relay_allows_clear;
1022 }
1023
1024 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1025 && ksess->consumer->enabled) {
1026 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1027 socket, node.node) {
1028 pthread_mutex_lock(socket->lock);
1029 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1030 ksess->consumer, socket,
1031 session->name, session->hostname,
1032 session->base_path,
1033 session->live_timer,
1034 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1035 session->creation_time,
1036 session->name_contains_creation_time);
1037 pthread_mutex_unlock(socket->lock);
1038 if (ret != LTTNG_OK) {
1039 goto error;
1040 }
1041 /* Session is now ready for network streaming. */
1042 session->net_handle = 1;
1043 }
1044 session->consumer->relay_major_version =
1045 ksess->consumer->relay_major_version;
1046 session->consumer->relay_minor_version =
1047 ksess->consumer->relay_minor_version;
1048 session->consumer->relay_allows_clear =
1049 ksess->consumer->relay_allows_clear;
1050 }
1051
1052 error:
1053 rcu_read_unlock();
1054 return ret;
1055 }
1056
1057 /*
1058 * Start a kernel session by opening all necessary streams.
1059 */
1060 int start_kernel_session(struct ltt_kernel_session *ksess)
1061 {
1062 int ret;
1063 struct ltt_kernel_channel *kchan;
1064
1065 /* Open kernel metadata */
1066 if (ksess->metadata == NULL && ksess->output_traces) {
1067 ret = kernel_open_metadata(ksess);
1068 if (ret < 0) {
1069 ret = LTTNG_ERR_KERN_META_FAIL;
1070 goto error;
1071 }
1072 }
1073
1074 /* Open kernel metadata stream */
1075 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1076 ret = kernel_open_metadata_stream(ksess);
1077 if (ret < 0) {
1078 ERR("Kernel create metadata stream failed");
1079 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1080 goto error;
1081 }
1082 }
1083
1084 /* For each channel */
1085 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1086 if (kchan->stream_count == 0) {
1087 ret = kernel_open_channel_stream(kchan);
1088 if (ret < 0) {
1089 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1090 goto error;
1091 }
1092 /* Update the stream global counter */
1093 ksess->stream_count_global += ret;
1094 }
1095 }
1096
1097 /* Setup kernel consumer socket and send fds to it */
1098 ret = init_kernel_tracing(ksess);
1099 if (ret != 0) {
1100 ret = LTTNG_ERR_KERN_START_FAIL;
1101 goto error;
1102 }
1103
1104 /* This start the kernel tracing */
1105 ret = kernel_start_session(ksess);
1106 if (ret < 0) {
1107 ret = LTTNG_ERR_KERN_START_FAIL;
1108 goto error;
1109 }
1110
1111 /* Quiescent wait after starting trace */
1112 kernel_wait_quiescent();
1113
1114 ksess->active = 1;
1115
1116 ret = LTTNG_OK;
1117
1118 error:
1119 return ret;
1120 }
1121
1122 int stop_kernel_session(struct ltt_kernel_session *ksess)
1123 {
1124 struct ltt_kernel_channel *kchan;
1125 bool error_occurred = false;
1126 int ret;
1127
1128 if (!ksess || !ksess->active) {
1129 return LTTNG_OK;
1130 }
1131 DBG("Stopping kernel tracing");
1132
1133 ret = kernel_stop_session(ksess);
1134 if (ret < 0) {
1135 ret = LTTNG_ERR_KERN_STOP_FAIL;
1136 goto error;
1137 }
1138
1139 kernel_wait_quiescent();
1140
1141 /* Flush metadata after stopping (if exists) */
1142 if (ksess->metadata_stream_fd >= 0) {
1143 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1144 if (ret < 0) {
1145 ERR("Kernel metadata flush failed");
1146 error_occurred = true;
1147 }
1148 }
1149
1150 /* Flush all buffers after stopping */
1151 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1152 ret = kernel_flush_buffer(kchan);
1153 if (ret < 0) {
1154 ERR("Kernel flush buffer error");
1155 error_occurred = true;
1156 }
1157 }
1158
1159 ksess->active = 0;
1160 if (error_occurred) {
1161 ret = LTTNG_ERR_UNK;
1162 } else {
1163 ret = LTTNG_OK;
1164 }
1165 error:
1166 return ret;
1167 }
1168
1169 /*
1170 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1171 */
1172 int cmd_disable_channel(struct ltt_session *session,
1173 enum lttng_domain_type domain, char *channel_name)
1174 {
1175 int ret;
1176 struct ltt_ust_session *usess;
1177
1178 usess = session->ust_session;
1179
1180 rcu_read_lock();
1181
1182 switch (domain) {
1183 case LTTNG_DOMAIN_KERNEL:
1184 {
1185 ret = channel_kernel_disable(session->kernel_session,
1186 channel_name);
1187 if (ret != LTTNG_OK) {
1188 goto error;
1189 }
1190
1191 kernel_wait_quiescent();
1192 break;
1193 }
1194 case LTTNG_DOMAIN_UST:
1195 {
1196 struct ltt_ust_channel *uchan;
1197 struct lttng_ht *chan_ht;
1198
1199 chan_ht = usess->domain_global.channels;
1200
1201 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1202 if (uchan == NULL) {
1203 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1204 goto error;
1205 }
1206
1207 ret = channel_ust_disable(usess, uchan);
1208 if (ret != LTTNG_OK) {
1209 goto error;
1210 }
1211 break;
1212 }
1213 default:
1214 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1215 goto error;
1216 }
1217
1218 ret = LTTNG_OK;
1219
1220 error:
1221 rcu_read_unlock();
1222 return ret;
1223 }
1224
1225 /*
1226 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1227 *
1228 * The wpipe arguments is used as a notifier for the kernel thread.
1229 */
1230 int cmd_enable_channel(struct command_ctx *cmd_ctx, int sock, int wpipe)
1231 {
1232 int ret;
1233 size_t channel_len;
1234 ssize_t sock_recv_len;
1235 struct lttng_channel *channel = NULL;
1236 struct lttng_buffer_view view;
1237 struct lttng_dynamic_buffer channel_buffer;
1238 const struct lttng_domain command_domain = cmd_ctx->lsm.domain;
1239
1240 lttng_dynamic_buffer_init(&channel_buffer);
1241 channel_len = (size_t) cmd_ctx->lsm.u.channel.length;
1242 ret = lttng_dynamic_buffer_set_size(&channel_buffer, channel_len);
1243 if (ret) {
1244 ret = LTTNG_ERR_NOMEM;
1245 goto end;
1246 }
1247
1248 sock_recv_len = lttcomm_recv_unix_sock(sock, channel_buffer.data,
1249 channel_len);
1250 if (sock_recv_len < 0 || sock_recv_len != channel_len) {
1251 ERR("Failed to receive \"enable channel\" command payload");
1252 ret = LTTNG_ERR_INVALID;
1253 goto end;
1254 }
1255
1256 view = lttng_buffer_view_from_dynamic_buffer(&channel_buffer, 0, channel_len);
1257 if (!lttng_buffer_view_is_valid(&view)) {
1258 ret = LTTNG_ERR_INVALID;
1259 goto end;
1260 }
1261
1262 if (lttng_channel_create_from_buffer(&view, &channel) != channel_len) {
1263 ERR("Invalid channel payload received in \"enable channel\" command");
1264 ret = LTTNG_ERR_INVALID;
1265 goto end;
1266 }
1267
1268 ret = cmd_enable_channel_internal(
1269 cmd_ctx->session, &command_domain, channel, wpipe);
1270
1271 end:
1272 lttng_dynamic_buffer_reset(&channel_buffer);
1273 lttng_channel_destroy(channel);
1274 return ret;
1275 }
1276
1277 static int cmd_enable_channel_internal(struct ltt_session *session,
1278 const struct lttng_domain *domain,
1279 const struct lttng_channel *_attr,
1280 int wpipe)
1281 {
1282 int ret;
1283 struct ltt_ust_session *usess = session->ust_session;
1284 struct lttng_ht *chan_ht;
1285 size_t len;
1286 struct lttng_channel *attr = NULL;
1287
1288 LTTNG_ASSERT(session);
1289 LTTNG_ASSERT(_attr);
1290 LTTNG_ASSERT(domain);
1291
1292 attr = lttng_channel_copy(_attr);
1293 if (!attr) {
1294 ret = -LTTNG_ERR_NOMEM;
1295 goto end;
1296 }
1297
1298 len = lttng_strnlen(attr->name, sizeof(attr->name));
1299
1300 /* Validate channel name */
1301 if (attr->name[0] == '.' ||
1302 memchr(attr->name, '/', len) != NULL) {
1303 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1304 goto end;
1305 }
1306
1307 DBG("Enabling channel %s for session %s", attr->name, session->name);
1308
1309 rcu_read_lock();
1310
1311 /*
1312 * If the session is a live session, remove the switch timer, the
1313 * live timer does the same thing but sends also synchronisation
1314 * beacons for inactive streams.
1315 */
1316 if (session->live_timer > 0) {
1317 attr->attr.live_timer_interval = session->live_timer;
1318 attr->attr.switch_timer_interval = 0;
1319 }
1320
1321 /* Check for feature support */
1322 switch (domain->type) {
1323 case LTTNG_DOMAIN_KERNEL:
1324 {
1325 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1326 /* Sampling position of buffer is not supported */
1327 WARN("Kernel tracer does not support buffer monitoring. "
1328 "Setting the monitor interval timer to 0 "
1329 "(disabled) for channel '%s' of session '%s'",
1330 attr->name, session->name);
1331 lttng_channel_set_monitor_timer_interval(attr, 0);
1332 }
1333 break;
1334 }
1335 case LTTNG_DOMAIN_UST:
1336 break;
1337 case LTTNG_DOMAIN_JUL:
1338 case LTTNG_DOMAIN_LOG4J:
1339 case LTTNG_DOMAIN_PYTHON:
1340 if (!agent_tracing_is_enabled()) {
1341 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1342 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1343 goto error;
1344 }
1345 break;
1346 default:
1347 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1348 goto error;
1349 }
1350
1351 switch (domain->type) {
1352 case LTTNG_DOMAIN_KERNEL:
1353 {
1354 struct ltt_kernel_channel *kchan;
1355
1356 kchan = trace_kernel_get_channel_by_name(
1357 attr->name, session->kernel_session);
1358 if (kchan == NULL) {
1359 /*
1360 * Don't try to create a channel if the session has been started at
1361 * some point in time before. The tracer does not allow it.
1362 */
1363 if (session->has_been_started) {
1364 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1365 goto error;
1366 }
1367
1368 if (session->snapshot.nb_output > 0 ||
1369 session->snapshot_mode) {
1370 /* Enforce mmap output for snapshot sessions. */
1371 attr->attr.output = LTTNG_EVENT_MMAP;
1372 }
1373 ret = channel_kernel_create(
1374 session->kernel_session, attr, wpipe);
1375 if (attr->name[0] != '\0') {
1376 session->kernel_session->has_non_default_channel = 1;
1377 }
1378 } else {
1379 ret = channel_kernel_enable(session->kernel_session, kchan);
1380 }
1381
1382 if (ret != LTTNG_OK) {
1383 goto error;
1384 }
1385
1386 kernel_wait_quiescent();
1387 break;
1388 }
1389 case LTTNG_DOMAIN_UST:
1390 case LTTNG_DOMAIN_JUL:
1391 case LTTNG_DOMAIN_LOG4J:
1392 case LTTNG_DOMAIN_PYTHON:
1393 {
1394 struct ltt_ust_channel *uchan;
1395
1396 /*
1397 * FIXME
1398 *
1399 * Current agent implementation limitations force us to allow
1400 * only one channel at once in "agent" subdomains. Each
1401 * subdomain has a default channel name which must be strictly
1402 * adhered to.
1403 */
1404 if (domain->type == LTTNG_DOMAIN_JUL) {
1405 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1406 LTTNG_SYMBOL_NAME_LEN)) {
1407 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1408 goto error;
1409 }
1410 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1411 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1412 LTTNG_SYMBOL_NAME_LEN)) {
1413 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1414 goto error;
1415 }
1416 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1417 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1418 LTTNG_SYMBOL_NAME_LEN)) {
1419 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1420 goto error;
1421 }
1422 }
1423
1424 chan_ht = usess->domain_global.channels;
1425
1426 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1427 if (uchan == NULL) {
1428 /*
1429 * Don't try to create a channel if the session has been started at
1430 * some point in time before. The tracer does not allow it.
1431 */
1432 if (session->has_been_started) {
1433 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1434 goto error;
1435 }
1436
1437 ret = channel_ust_create(usess, attr, domain->buf_type);
1438 if (attr->name[0] != '\0') {
1439 usess->has_non_default_channel = 1;
1440 }
1441 } else {
1442 ret = channel_ust_enable(usess, uchan);
1443 }
1444 break;
1445 }
1446 default:
1447 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1448 goto error;
1449 }
1450
1451 if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1452 session->has_non_mmap_channel = true;
1453 }
1454 error:
1455 rcu_read_unlock();
1456 end:
1457 lttng_channel_destroy(attr);
1458 return ret;
1459 }
1460
1461 enum lttng_error_code cmd_process_attr_tracker_get_tracking_policy(
1462 struct ltt_session *session,
1463 enum lttng_domain_type domain,
1464 enum lttng_process_attr process_attr,
1465 enum lttng_tracking_policy *policy)
1466 {
1467 enum lttng_error_code ret_code = LTTNG_OK;
1468 const struct process_attr_tracker *tracker;
1469
1470 switch (domain) {
1471 case LTTNG_DOMAIN_KERNEL:
1472 if (!session->kernel_session) {
1473 ret_code = LTTNG_ERR_INVALID;
1474 goto end;
1475 }
1476 tracker = kernel_get_process_attr_tracker(
1477 session->kernel_session, process_attr);
1478 break;
1479 case LTTNG_DOMAIN_UST:
1480 if (!session->ust_session) {
1481 ret_code = LTTNG_ERR_INVALID;
1482 goto end;
1483 }
1484 tracker = trace_ust_get_process_attr_tracker(
1485 session->ust_session, process_attr);
1486 break;
1487 default:
1488 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1489 goto end;
1490 }
1491 if (tracker) {
1492 *policy = process_attr_tracker_get_tracking_policy(tracker);
1493 } else {
1494 ret_code = LTTNG_ERR_INVALID;
1495 }
1496 end:
1497 return ret_code;
1498 }
1499
1500 enum lttng_error_code cmd_process_attr_tracker_set_tracking_policy(
1501 struct ltt_session *session,
1502 enum lttng_domain_type domain,
1503 enum lttng_process_attr process_attr,
1504 enum lttng_tracking_policy policy)
1505 {
1506 enum lttng_error_code ret_code = LTTNG_OK;
1507
1508 switch (policy) {
1509 case LTTNG_TRACKING_POLICY_INCLUDE_SET:
1510 case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
1511 case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
1512 break;
1513 default:
1514 ret_code = LTTNG_ERR_INVALID;
1515 goto end;
1516 }
1517
1518 switch (domain) {
1519 case LTTNG_DOMAIN_KERNEL:
1520 if (!session->kernel_session) {
1521 ret_code = LTTNG_ERR_INVALID;
1522 goto end;
1523 }
1524 ret_code = kernel_process_attr_tracker_set_tracking_policy(
1525 session->kernel_session, process_attr, policy);
1526 break;
1527 case LTTNG_DOMAIN_UST:
1528 if (!session->ust_session) {
1529 ret_code = LTTNG_ERR_INVALID;
1530 goto end;
1531 }
1532 ret_code = trace_ust_process_attr_tracker_set_tracking_policy(
1533 session->ust_session, process_attr, policy);
1534 break;
1535 default:
1536 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1537 break;
1538 }
1539 end:
1540 return ret_code;
1541 }
1542
1543 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_add_value(
1544 struct ltt_session *session,
1545 enum lttng_domain_type domain,
1546 enum lttng_process_attr process_attr,
1547 const struct process_attr_value *value)
1548 {
1549 enum lttng_error_code ret_code = LTTNG_OK;
1550
1551 switch (domain) {
1552 case LTTNG_DOMAIN_KERNEL:
1553 if (!session->kernel_session) {
1554 ret_code = LTTNG_ERR_INVALID;
1555 goto end;
1556 }
1557 ret_code = kernel_process_attr_tracker_inclusion_set_add_value(
1558 session->kernel_session, process_attr, value);
1559 break;
1560 case LTTNG_DOMAIN_UST:
1561 if (!session->ust_session) {
1562 ret_code = LTTNG_ERR_INVALID;
1563 goto end;
1564 }
1565 ret_code = trace_ust_process_attr_tracker_inclusion_set_add_value(
1566 session->ust_session, process_attr, value);
1567 break;
1568 default:
1569 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1570 break;
1571 }
1572 end:
1573 return ret_code;
1574 }
1575
1576 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_remove_value(
1577 struct ltt_session *session,
1578 enum lttng_domain_type domain,
1579 enum lttng_process_attr process_attr,
1580 const struct process_attr_value *value)
1581 {
1582 enum lttng_error_code ret_code = LTTNG_OK;
1583
1584 switch (domain) {
1585 case LTTNG_DOMAIN_KERNEL:
1586 if (!session->kernel_session) {
1587 ret_code = LTTNG_ERR_INVALID;
1588 goto end;
1589 }
1590 ret_code = kernel_process_attr_tracker_inclusion_set_remove_value(
1591 session->kernel_session, process_attr, value);
1592 break;
1593 case LTTNG_DOMAIN_UST:
1594 if (!session->ust_session) {
1595 ret_code = LTTNG_ERR_INVALID;
1596 goto end;
1597 }
1598 ret_code = trace_ust_process_attr_tracker_inclusion_set_remove_value(
1599 session->ust_session, process_attr, value);
1600 break;
1601 default:
1602 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1603 break;
1604 }
1605 end:
1606 return ret_code;
1607 }
1608
1609 enum lttng_error_code cmd_process_attr_tracker_get_inclusion_set(
1610 struct ltt_session *session,
1611 enum lttng_domain_type domain,
1612 enum lttng_process_attr process_attr,
1613 struct lttng_process_attr_values **values)
1614 {
1615 enum lttng_error_code ret_code = LTTNG_OK;
1616 const struct process_attr_tracker *tracker;
1617 enum process_attr_tracker_status status;
1618
1619 switch (domain) {
1620 case LTTNG_DOMAIN_KERNEL:
1621 if (!session->kernel_session) {
1622 ret_code = LTTNG_ERR_INVALID;
1623 goto end;
1624 }
1625 tracker = kernel_get_process_attr_tracker(
1626 session->kernel_session, process_attr);
1627 break;
1628 case LTTNG_DOMAIN_UST:
1629 if (!session->ust_session) {
1630 ret_code = LTTNG_ERR_INVALID;
1631 goto end;
1632 }
1633 tracker = trace_ust_get_process_attr_tracker(
1634 session->ust_session, process_attr);
1635 break;
1636 default:
1637 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1638 goto end;
1639 }
1640
1641 if (!tracker) {
1642 ret_code = LTTNG_ERR_INVALID;
1643 goto end;
1644 }
1645
1646 status = process_attr_tracker_get_inclusion_set(tracker, values);
1647 switch (status) {
1648 case PROCESS_ATTR_TRACKER_STATUS_OK:
1649 ret_code = LTTNG_OK;
1650 break;
1651 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1652 ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1653 break;
1654 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1655 ret_code = LTTNG_ERR_NOMEM;
1656 break;
1657 default:
1658 ret_code = LTTNG_ERR_UNK;
1659 break;
1660 }
1661
1662 end:
1663 return ret_code;
1664 }
1665
1666 /*
1667 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1668 */
1669 int cmd_disable_event(struct command_ctx *cmd_ctx,
1670 struct lttng_event *event,
1671 char *filter_expression,
1672 struct lttng_bytecode *bytecode,
1673 struct lttng_event_exclusion *exclusion)
1674 {
1675 int ret;
1676 const char *event_name;
1677 const struct ltt_session *session = cmd_ctx->session;
1678 const char *channel_name = cmd_ctx->lsm.u.disable.channel_name;
1679 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1680
1681 DBG("Disable event command for event \'%s\'", event->name);
1682
1683 /*
1684 * Filter and exclusions are simply not handled by the
1685 * disable event command at this time.
1686 *
1687 * FIXME
1688 */
1689 (void) filter_expression;
1690 (void) exclusion;
1691
1692 /* Ignore the presence of filter or exclusion for the event */
1693 event->filter = 0;
1694 event->exclusion = 0;
1695
1696 event_name = event->name;
1697
1698 /* Error out on unhandled search criteria */
1699 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1700 || event->pid || event->filter || event->exclusion) {
1701 ret = LTTNG_ERR_UNK;
1702 goto error;
1703 }
1704
1705 rcu_read_lock();
1706
1707 switch (domain) {
1708 case LTTNG_DOMAIN_KERNEL:
1709 {
1710 struct ltt_kernel_channel *kchan;
1711 struct ltt_kernel_session *ksess;
1712
1713 ksess = session->kernel_session;
1714
1715 /*
1716 * If a non-default channel has been created in the
1717 * session, explicitely require that -c chan_name needs
1718 * to be provided.
1719 */
1720 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1721 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1722 goto error_unlock;
1723 }
1724
1725 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1726 if (kchan == NULL) {
1727 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1728 goto error_unlock;
1729 }
1730
1731 switch (event->type) {
1732 case LTTNG_EVENT_ALL:
1733 case LTTNG_EVENT_TRACEPOINT:
1734 case LTTNG_EVENT_SYSCALL:
1735 case LTTNG_EVENT_PROBE:
1736 case LTTNG_EVENT_FUNCTION:
1737 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1738 if (event_name[0] == '\0') {
1739 ret = event_kernel_disable_event(kchan,
1740 NULL, event->type);
1741 } else {
1742 ret = event_kernel_disable_event(kchan,
1743 event_name, event->type);
1744 }
1745 if (ret != LTTNG_OK) {
1746 goto error_unlock;
1747 }
1748 break;
1749 default:
1750 ret = LTTNG_ERR_UNK;
1751 goto error_unlock;
1752 }
1753
1754 kernel_wait_quiescent();
1755 break;
1756 }
1757 case LTTNG_DOMAIN_UST:
1758 {
1759 struct ltt_ust_channel *uchan;
1760 struct ltt_ust_session *usess;
1761
1762 usess = session->ust_session;
1763
1764 if (validate_ust_event_name(event_name)) {
1765 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1766 goto error_unlock;
1767 }
1768
1769 /*
1770 * If a non-default channel has been created in the
1771 * session, explicitly require that -c chan_name needs
1772 * to be provided.
1773 */
1774 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1775 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1776 goto error_unlock;
1777 }
1778
1779 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1780 channel_name);
1781 if (uchan == NULL) {
1782 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1783 goto error_unlock;
1784 }
1785
1786 switch (event->type) {
1787 case LTTNG_EVENT_ALL:
1788 /*
1789 * An empty event name means that everything
1790 * should be disabled.
1791 */
1792 if (event->name[0] == '\0') {
1793 ret = event_ust_disable_all_tracepoints(usess, uchan);
1794 } else {
1795 ret = event_ust_disable_tracepoint(usess, uchan,
1796 event_name);
1797 }
1798 if (ret != LTTNG_OK) {
1799 goto error_unlock;
1800 }
1801 break;
1802 default:
1803 ret = LTTNG_ERR_UNK;
1804 goto error_unlock;
1805 }
1806
1807 DBG3("Disable UST event %s in channel %s completed", event_name,
1808 channel_name);
1809 break;
1810 }
1811 case LTTNG_DOMAIN_LOG4J:
1812 case LTTNG_DOMAIN_JUL:
1813 case LTTNG_DOMAIN_PYTHON:
1814 {
1815 struct agent *agt;
1816 struct ltt_ust_session *usess = session->ust_session;
1817
1818 LTTNG_ASSERT(usess);
1819
1820 switch (event->type) {
1821 case LTTNG_EVENT_ALL:
1822 break;
1823 default:
1824 ret = LTTNG_ERR_UNK;
1825 goto error_unlock;
1826 }
1827
1828 agt = trace_ust_find_agent(usess, domain);
1829 if (!agt) {
1830 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1831 goto error_unlock;
1832 }
1833 /*
1834 * An empty event name means that everything
1835 * should be disabled.
1836 */
1837 if (event->name[0] == '\0') {
1838 ret = event_agent_disable_all(usess, agt);
1839 } else {
1840 ret = event_agent_disable(usess, agt, event_name);
1841 }
1842 if (ret != LTTNG_OK) {
1843 goto error_unlock;
1844 }
1845
1846 break;
1847 }
1848 default:
1849 ret = LTTNG_ERR_UND;
1850 goto error_unlock;
1851 }
1852
1853 ret = LTTNG_OK;
1854
1855 error_unlock:
1856 rcu_read_unlock();
1857 error:
1858 free(exclusion);
1859 free(bytecode);
1860 free(filter_expression);
1861 return ret;
1862 }
1863
1864 /*
1865 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1866 */
1867 int cmd_add_context(struct command_ctx *cmd_ctx,
1868 const struct lttng_event_context *event_context, int kwpipe)
1869 {
1870 int ret, chan_kern_created = 0, chan_ust_created = 0;
1871 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1872 const struct ltt_session *session = cmd_ctx->session;
1873 const char *channel_name = cmd_ctx->lsm.u.context.channel_name;
1874
1875 /*
1876 * Don't try to add a context if the session has been started at
1877 * some point in time before. The tracer does not allow it and would
1878 * result in a corrupted trace.
1879 */
1880 if (cmd_ctx->session->has_been_started) {
1881 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1882 goto end;
1883 }
1884
1885 switch (domain) {
1886 case LTTNG_DOMAIN_KERNEL:
1887 LTTNG_ASSERT(session->kernel_session);
1888
1889 if (session->kernel_session->channel_count == 0) {
1890 /* Create default channel */
1891 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1892 if (ret != LTTNG_OK) {
1893 goto error;
1894 }
1895 chan_kern_created = 1;
1896 }
1897 /* Add kernel context to kernel tracer */
1898 ret = context_kernel_add(session->kernel_session,
1899 event_context, channel_name);
1900 if (ret != LTTNG_OK) {
1901 goto error;
1902 }
1903 break;
1904 case LTTNG_DOMAIN_JUL:
1905 case LTTNG_DOMAIN_LOG4J:
1906 {
1907 /*
1908 * Validate channel name.
1909 * If no channel name is given and the domain is JUL or LOG4J,
1910 * set it to the appropriate domain-specific channel name. If
1911 * a name is provided but does not match the expexted channel
1912 * name, return an error.
1913 */
1914 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1915 strcmp(channel_name,
1916 DEFAULT_JUL_CHANNEL_NAME)) {
1917 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1918 goto error;
1919 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1920 strcmp(channel_name,
1921 DEFAULT_LOG4J_CHANNEL_NAME)) {
1922 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1923 goto error;
1924 }
1925 /* break is _not_ missing here. */
1926 }
1927 case LTTNG_DOMAIN_UST:
1928 {
1929 struct ltt_ust_session *usess = session->ust_session;
1930 unsigned int chan_count;
1931
1932 LTTNG_ASSERT(usess);
1933
1934 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1935 if (chan_count == 0) {
1936 struct lttng_channel *attr;
1937 /* Create default channel */
1938 attr = channel_new_default_attr(domain, usess->buffer_type);
1939 if (attr == NULL) {
1940 ret = LTTNG_ERR_FATAL;
1941 goto error;
1942 }
1943
1944 ret = channel_ust_create(usess, attr, usess->buffer_type);
1945 if (ret != LTTNG_OK) {
1946 free(attr);
1947 goto error;
1948 }
1949 channel_attr_destroy(attr);
1950 chan_ust_created = 1;
1951 }
1952
1953 ret = context_ust_add(usess, domain, event_context,
1954 channel_name);
1955 if (ret != LTTNG_OK) {
1956 goto error;
1957 }
1958 break;
1959 }
1960 default:
1961 ret = LTTNG_ERR_UND;
1962 goto error;
1963 }
1964
1965 ret = LTTNG_OK;
1966 goto end;
1967
1968 error:
1969 if (chan_kern_created) {
1970 struct ltt_kernel_channel *kchan =
1971 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1972 session->kernel_session);
1973 /* Created previously, this should NOT fail. */
1974 LTTNG_ASSERT(kchan);
1975 kernel_destroy_channel(kchan);
1976 }
1977
1978 if (chan_ust_created) {
1979 struct ltt_ust_channel *uchan =
1980 trace_ust_find_channel_by_name(
1981 session->ust_session->domain_global.channels,
1982 DEFAULT_CHANNEL_NAME);
1983 /* Created previously, this should NOT fail. */
1984 LTTNG_ASSERT(uchan);
1985 /* Remove from the channel list of the session. */
1986 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1987 uchan);
1988 trace_ust_destroy_channel(uchan);
1989 }
1990 end:
1991 return ret;
1992 }
1993
1994 static inline bool name_starts_with(const char *name, const char *prefix)
1995 {
1996 const size_t max_cmp_len = std::min(strlen(prefix), (size_t) LTTNG_SYMBOL_NAME_LEN);
1997
1998 return !strncmp(name, prefix, max_cmp_len);
1999 }
2000
2001 /* Perform userspace-specific event name validation */
2002 static int validate_ust_event_name(const char *name)
2003 {
2004 int ret = 0;
2005
2006 if (!name) {
2007 ret = -1;
2008 goto end;
2009 }
2010
2011 /*
2012 * Check name against all internal UST event component namespaces used
2013 * by the agents.
2014 */
2015 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2016 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2017 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2018 ret = -1;
2019 }
2020
2021 end:
2022 return ret;
2023 }
2024
2025 /*
2026 * Internal version of cmd_enable_event() with a supplemental
2027 * "internal_event" flag which is used to enable internal events which should
2028 * be hidden from clients. Such events are used in the agent implementation to
2029 * enable the events through which all "agent" events are funeled.
2030 */
2031 static int _cmd_enable_event(struct ltt_session *session,
2032 const struct lttng_domain *domain,
2033 char *channel_name, struct lttng_event *event,
2034 char *filter_expression,
2035 struct lttng_bytecode *filter,
2036 struct lttng_event_exclusion *exclusion,
2037 int wpipe, bool internal_event)
2038 {
2039 int ret = 0, channel_created = 0;
2040 struct lttng_channel *attr = NULL;
2041
2042 LTTNG_ASSERT(session);
2043 LTTNG_ASSERT(event);
2044 LTTNG_ASSERT(channel_name);
2045
2046 /* If we have a filter, we must have its filter expression */
2047 LTTNG_ASSERT(!(!!filter_expression ^ !!filter));
2048
2049 /* Normalize event name as a globbing pattern */
2050 strutils_normalize_star_glob_pattern(event->name);
2051
2052 /* Normalize exclusion names as globbing patterns */
2053 if (exclusion) {
2054 size_t i;
2055
2056 for (i = 0; i < exclusion->count; i++) {
2057 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2058
2059 strutils_normalize_star_glob_pattern(name);
2060 }
2061 }
2062
2063 DBG("Enable event command for event \'%s\'", event->name);
2064
2065 rcu_read_lock();
2066
2067 switch (domain->type) {
2068 case LTTNG_DOMAIN_KERNEL:
2069 {
2070 struct ltt_kernel_channel *kchan;
2071
2072 /*
2073 * If a non-default channel has been created in the
2074 * session, explicitely require that -c chan_name needs
2075 * to be provided.
2076 */
2077 if (session->kernel_session->has_non_default_channel
2078 && channel_name[0] == '\0') {
2079 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2080 goto error;
2081 }
2082
2083 kchan = trace_kernel_get_channel_by_name(channel_name,
2084 session->kernel_session);
2085 if (kchan == NULL) {
2086 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2087 LTTNG_BUFFER_GLOBAL);
2088 if (attr == NULL) {
2089 ret = LTTNG_ERR_FATAL;
2090 goto error;
2091 }
2092 if (lttng_strncpy(attr->name, channel_name,
2093 sizeof(attr->name))) {
2094 ret = LTTNG_ERR_INVALID;
2095 goto error;
2096 }
2097
2098 ret = cmd_enable_channel_internal(
2099 session, domain, attr, wpipe);
2100 if (ret != LTTNG_OK) {
2101 goto error;
2102 }
2103 channel_created = 1;
2104 }
2105
2106 /* Get the newly created kernel channel pointer */
2107 kchan = trace_kernel_get_channel_by_name(channel_name,
2108 session->kernel_session);
2109 if (kchan == NULL) {
2110 /* This sould not happen... */
2111 ret = LTTNG_ERR_FATAL;
2112 goto error;
2113 }
2114
2115 switch (event->type) {
2116 case LTTNG_EVENT_ALL:
2117 {
2118 char *filter_expression_a = NULL;
2119 struct lttng_bytecode *filter_a = NULL;
2120
2121 /*
2122 * We need to duplicate filter_expression and filter,
2123 * because ownership is passed to first enable
2124 * event.
2125 */
2126 if (filter_expression) {
2127 filter_expression_a = strdup(filter_expression);
2128 if (!filter_expression_a) {
2129 ret = LTTNG_ERR_FATAL;
2130 goto error;
2131 }
2132 }
2133 if (filter) {
2134 filter_a = (lttng_bytecode *) zmalloc(sizeof(*filter_a) + filter->len);
2135 if (!filter_a) {
2136 free(filter_expression_a);
2137 ret = LTTNG_ERR_FATAL;
2138 goto error;
2139 }
2140 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2141 }
2142 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2143 ret = event_kernel_enable_event(kchan, event,
2144 filter_expression, filter);
2145 /* We have passed ownership */
2146 filter_expression = NULL;
2147 filter = NULL;
2148 if (ret != LTTNG_OK) {
2149 if (channel_created) {
2150 /* Let's not leak a useless channel. */
2151 kernel_destroy_channel(kchan);
2152 }
2153 free(filter_expression_a);
2154 free(filter_a);
2155 goto error;
2156 }
2157 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2158 ret = event_kernel_enable_event(kchan, event,
2159 filter_expression_a, filter_a);
2160 /* We have passed ownership */
2161 filter_expression_a = NULL;
2162 filter_a = NULL;
2163 if (ret != LTTNG_OK) {
2164 goto error;
2165 }
2166 break;
2167 }
2168 case LTTNG_EVENT_PROBE:
2169 case LTTNG_EVENT_USERSPACE_PROBE:
2170 case LTTNG_EVENT_FUNCTION:
2171 case LTTNG_EVENT_FUNCTION_ENTRY:
2172 case LTTNG_EVENT_TRACEPOINT:
2173 ret = event_kernel_enable_event(kchan, event,
2174 filter_expression, filter);
2175 /* We have passed ownership */
2176 filter_expression = NULL;
2177 filter = NULL;
2178 if (ret != LTTNG_OK) {
2179 if (channel_created) {
2180 /* Let's not leak a useless channel. */
2181 kernel_destroy_channel(kchan);
2182 }
2183 goto error;
2184 }
2185 break;
2186 case LTTNG_EVENT_SYSCALL:
2187 ret = event_kernel_enable_event(kchan, event,
2188 filter_expression, filter);
2189 /* We have passed ownership */
2190 filter_expression = NULL;
2191 filter = NULL;
2192 if (ret != LTTNG_OK) {
2193 goto error;
2194 }
2195 break;
2196 default:
2197 ret = LTTNG_ERR_UNK;
2198 goto error;
2199 }
2200
2201 kernel_wait_quiescent();
2202 break;
2203 }
2204 case LTTNG_DOMAIN_UST:
2205 {
2206 struct ltt_ust_channel *uchan;
2207 struct ltt_ust_session *usess = session->ust_session;
2208
2209 LTTNG_ASSERT(usess);
2210
2211 /*
2212 * If a non-default channel has been created in the
2213 * session, explicitely require that -c chan_name needs
2214 * to be provided.
2215 */
2216 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2217 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2218 goto error;
2219 }
2220
2221 /* Get channel from global UST domain */
2222 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2223 channel_name);
2224 if (uchan == NULL) {
2225 /* Create default channel */
2226 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2227 usess->buffer_type);
2228 if (attr == NULL) {
2229 ret = LTTNG_ERR_FATAL;
2230 goto error;
2231 }
2232 if (lttng_strncpy(attr->name, channel_name,
2233 sizeof(attr->name))) {
2234 ret = LTTNG_ERR_INVALID;
2235 goto error;
2236 }
2237
2238 ret = cmd_enable_channel_internal(
2239 session, domain, attr, wpipe);
2240 if (ret != LTTNG_OK) {
2241 goto error;
2242 }
2243
2244 /* Get the newly created channel reference back */
2245 uchan = trace_ust_find_channel_by_name(
2246 usess->domain_global.channels, channel_name);
2247 LTTNG_ASSERT(uchan);
2248 }
2249
2250 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2251 /*
2252 * Don't allow users to add UST events to channels which
2253 * are assigned to a userspace subdomain (JUL, Log4J,
2254 * Python, etc.).
2255 */
2256 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2257 goto error;
2258 }
2259
2260 if (!internal_event) {
2261 /*
2262 * Ensure the event name is not reserved for internal
2263 * use.
2264 */
2265 ret = validate_ust_event_name(event->name);
2266 if (ret) {
2267 WARN("Userspace event name %s failed validation.",
2268 event->name);
2269 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2270 goto error;
2271 }
2272 }
2273
2274 /* At this point, the session and channel exist on the tracer */
2275 ret = event_ust_enable_tracepoint(usess, uchan, event,
2276 filter_expression, filter, exclusion,
2277 internal_event);
2278 /* We have passed ownership */
2279 filter_expression = NULL;
2280 filter = NULL;
2281 exclusion = NULL;
2282 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2283 goto already_enabled;
2284 } else if (ret != LTTNG_OK) {
2285 goto error;
2286 }
2287 break;
2288 }
2289 case LTTNG_DOMAIN_LOG4J:
2290 case LTTNG_DOMAIN_JUL:
2291 case LTTNG_DOMAIN_PYTHON:
2292 {
2293 const char *default_event_name, *default_chan_name;
2294 struct agent *agt;
2295 struct lttng_event uevent;
2296 struct lttng_domain tmp_dom;
2297 struct ltt_ust_session *usess = session->ust_session;
2298
2299 LTTNG_ASSERT(usess);
2300
2301 if (!agent_tracing_is_enabled()) {
2302 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2303 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2304 goto error;
2305 }
2306
2307 agt = trace_ust_find_agent(usess, domain->type);
2308 if (!agt) {
2309 agt = agent_create(domain->type);
2310 if (!agt) {
2311 ret = LTTNG_ERR_NOMEM;
2312 goto error;
2313 }
2314 agent_add(agt, usess->agents);
2315 }
2316
2317 /* Create the default tracepoint. */
2318 memset(&uevent, 0, sizeof(uevent));
2319 uevent.type = LTTNG_EVENT_TRACEPOINT;
2320 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2321 default_event_name = event_get_default_agent_ust_name(
2322 domain->type);
2323 if (!default_event_name) {
2324 ret = LTTNG_ERR_FATAL;
2325 goto error;
2326 }
2327 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2328 uevent.name[sizeof(uevent.name) - 1] = '\0';
2329
2330 /*
2331 * The domain type is changed because we are about to enable the
2332 * default channel and event for the JUL domain that are hardcoded.
2333 * This happens in the UST domain.
2334 */
2335 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2336 tmp_dom.type = LTTNG_DOMAIN_UST;
2337
2338 switch (domain->type) {
2339 case LTTNG_DOMAIN_LOG4J:
2340 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2341 break;
2342 case LTTNG_DOMAIN_JUL:
2343 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2344 break;
2345 case LTTNG_DOMAIN_PYTHON:
2346 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2347 break;
2348 default:
2349 /* The switch/case we are in makes this impossible */
2350 abort();
2351 }
2352
2353 {
2354 char *filter_expression_copy = NULL;
2355 struct lttng_bytecode *filter_copy = NULL;
2356
2357 if (filter) {
2358 const size_t filter_size = sizeof(
2359 struct lttng_bytecode)
2360 + filter->len;
2361
2362 filter_copy = (lttng_bytecode *) zmalloc(filter_size);
2363 if (!filter_copy) {
2364 ret = LTTNG_ERR_NOMEM;
2365 goto error;
2366 }
2367 memcpy(filter_copy, filter, filter_size);
2368
2369 filter_expression_copy =
2370 strdup(filter_expression);
2371 if (!filter_expression) {
2372 ret = LTTNG_ERR_NOMEM;
2373 }
2374
2375 if (!filter_expression_copy || !filter_copy) {
2376 free(filter_expression_copy);
2377 free(filter_copy);
2378 goto error;
2379 }
2380 }
2381
2382 ret = cmd_enable_event_internal(session, &tmp_dom,
2383 (char *) default_chan_name,
2384 &uevent, filter_expression_copy,
2385 filter_copy, NULL, wpipe);
2386 }
2387
2388 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2389 goto already_enabled;
2390 } else if (ret != LTTNG_OK) {
2391 goto error;
2392 }
2393
2394 /* The wild card * means that everything should be enabled. */
2395 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2396 ret = event_agent_enable_all(usess, agt, event, filter,
2397 filter_expression);
2398 } else {
2399 ret = event_agent_enable(usess, agt, event, filter,
2400 filter_expression);
2401 }
2402 filter = NULL;
2403 filter_expression = NULL;
2404 if (ret != LTTNG_OK) {
2405 goto error;
2406 }
2407
2408 break;
2409 }
2410 default:
2411 ret = LTTNG_ERR_UND;
2412 goto error;
2413 }
2414
2415 ret = LTTNG_OK;
2416
2417 already_enabled:
2418 error:
2419 free(filter_expression);
2420 free(filter);
2421 free(exclusion);
2422 channel_attr_destroy(attr);
2423 rcu_read_unlock();
2424 return ret;
2425 }
2426
2427 /*
2428 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2429 * We own filter, exclusion, and filter_expression.
2430 */
2431 int cmd_enable_event(struct command_ctx *cmd_ctx,
2432 struct lttng_event *event,
2433 char *filter_expression,
2434 struct lttng_event_exclusion *exclusion,
2435 struct lttng_bytecode *bytecode,
2436 int wpipe)
2437 {
2438 int ret;
2439 /*
2440 * Copied to ensure proper alignment since 'lsm' is a packed structure.
2441 */
2442 const lttng_domain command_domain = cmd_ctx->lsm.domain;
2443
2444 /*
2445 * The ownership of the following parameters is transferred to
2446 * _cmd_enable_event:
2447 *
2448 * - filter_expression,
2449 * - bytecode,
2450 * - exclusion
2451 */
2452 ret = _cmd_enable_event(cmd_ctx->session,
2453 &command_domain,
2454 cmd_ctx->lsm.u.enable.channel_name, event,
2455 filter_expression, bytecode, exclusion, wpipe, false);
2456 filter_expression = NULL;
2457 bytecode = NULL;
2458 exclusion = NULL;
2459 return ret;
2460 }
2461
2462 /*
2463 * Enable an event which is internal to LTTng. An internal should
2464 * never be made visible to clients and are immune to checks such as
2465 * reserved names.
2466 */
2467 static int cmd_enable_event_internal(struct ltt_session *session,
2468 const struct lttng_domain *domain,
2469 char *channel_name, struct lttng_event *event,
2470 char *filter_expression,
2471 struct lttng_bytecode *filter,
2472 struct lttng_event_exclusion *exclusion,
2473 int wpipe)
2474 {
2475 return _cmd_enable_event(session, domain, channel_name, event,
2476 filter_expression, filter, exclusion, wpipe, true);
2477 }
2478
2479 /*
2480 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2481 */
2482 enum lttng_error_code cmd_list_tracepoints(enum lttng_domain_type domain,
2483 struct lttng_payload *reply_payload)
2484 {
2485 enum lttng_error_code ret_code;
2486 int ret;
2487 ssize_t i, nb_events = 0;
2488 struct lttng_event *events = NULL;
2489 struct lttcomm_list_command_header reply_command_header = {};
2490 size_t reply_command_header_offset;
2491
2492 assert(reply_payload);
2493
2494 /* Reserve space for command reply header. */
2495 reply_command_header_offset = reply_payload->buffer.size;
2496 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2497 reply_command_header_offset +
2498 sizeof(struct lttcomm_list_command_header));
2499 if (ret) {
2500 ret_code = LTTNG_ERR_NOMEM;
2501 goto error;
2502 }
2503
2504 switch (domain) {
2505 case LTTNG_DOMAIN_KERNEL:
2506 nb_events = kernel_list_events(&events);
2507 if (nb_events < 0) {
2508 ret_code = LTTNG_ERR_KERN_LIST_FAIL;
2509 goto error;
2510 }
2511 break;
2512 case LTTNG_DOMAIN_UST:
2513 nb_events = ust_app_list_events(&events);
2514 if (nb_events < 0) {
2515 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2516 goto error;
2517 }
2518 break;
2519 case LTTNG_DOMAIN_LOG4J:
2520 case LTTNG_DOMAIN_JUL:
2521 case LTTNG_DOMAIN_PYTHON:
2522 nb_events = agent_list_events(&events, domain);
2523 if (nb_events < 0) {
2524 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2525 goto error;
2526 }
2527 break;
2528 default:
2529 ret_code = LTTNG_ERR_UND;
2530 goto error;
2531 }
2532
2533 for (i = 0; i < nb_events; i++) {
2534 ret = lttng_event_serialize(&events[i], 0, NULL, NULL, 0, NULL,
2535 reply_payload);
2536 if (ret) {
2537 ret_code = LTTNG_ERR_NOMEM;
2538 goto error;
2539 }
2540 }
2541
2542 if (nb_events > UINT32_MAX) {
2543 ERR("Tracepoint count would overflow the tracepoint listing command's reply");
2544 ret_code = LTTNG_ERR_OVERFLOW;
2545 goto error;
2546 }
2547
2548 /* Update command reply header. */
2549 reply_command_header.count = (uint32_t) nb_events;
2550 memcpy(reply_payload->buffer.data + reply_command_header_offset, &reply_command_header,
2551 sizeof(reply_command_header));
2552
2553 ret_code = LTTNG_OK;
2554 error:
2555 free(events);
2556 return ret_code;
2557 }
2558
2559 /*
2560 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2561 */
2562 enum lttng_error_code cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2563 struct lttng_payload *reply)
2564 {
2565 enum lttng_error_code ret_code;
2566 int ret;
2567 unsigned int i, nb_fields;
2568 struct lttng_event_field *fields = NULL;
2569 struct lttcomm_list_command_header reply_command_header = {};
2570 size_t reply_command_header_offset;
2571
2572 assert(reply);
2573
2574 /* Reserve space for command reply header. */
2575 reply_command_header_offset = reply->buffer.size;
2576 ret = lttng_dynamic_buffer_set_size(&reply->buffer,
2577 reply_command_header_offset +
2578 sizeof(struct lttcomm_list_command_header));
2579 if (ret) {
2580 ret_code = LTTNG_ERR_NOMEM;
2581 goto error;
2582 }
2583
2584 switch (domain) {
2585 case LTTNG_DOMAIN_UST:
2586 ret = ust_app_list_event_fields(&fields);
2587 if (ret < 0) {
2588 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2589 goto error;
2590 }
2591
2592 break;
2593 case LTTNG_DOMAIN_KERNEL:
2594 default: /* fall-through */
2595 ret_code = LTTNG_ERR_UND;
2596 goto error;
2597 }
2598
2599 nb_fields = ret;
2600
2601 for (i = 0; i < nb_fields; i++) {
2602 ret = lttng_event_field_serialize(&fields[i], reply);
2603 if (ret) {
2604 ret_code = LTTNG_ERR_NOMEM;
2605 goto error;
2606 }
2607 }
2608
2609 if (nb_fields > UINT32_MAX) {
2610 ERR("Tracepoint field count would overflow the tracepoint field listing command's reply");
2611 ret_code = LTTNG_ERR_OVERFLOW;
2612 goto error;
2613 }
2614
2615 /* Update command reply header. */
2616 reply_command_header.count = (uint32_t) nb_fields;
2617
2618 memcpy(reply->buffer.data + reply_command_header_offset, &reply_command_header,
2619 sizeof(reply_command_header));
2620
2621 ret_code = LTTNG_OK;
2622
2623 error:
2624 free(fields);
2625 return ret_code;
2626 }
2627
2628 enum lttng_error_code cmd_list_syscalls(
2629 struct lttng_payload *reply_payload)
2630 {
2631 enum lttng_error_code ret_code;
2632 ssize_t nb_events, i;
2633 int ret;
2634 struct lttng_event *events = NULL;
2635 struct lttcomm_list_command_header reply_command_header = {};
2636 size_t reply_command_header_offset;
2637
2638 assert(reply_payload);
2639
2640 /* Reserve space for command reply header. */
2641 reply_command_header_offset = reply_payload->buffer.size;
2642 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2643 reply_command_header_offset +
2644 sizeof(struct lttcomm_list_command_header));
2645 if (ret) {
2646 ret_code = LTTNG_ERR_NOMEM;
2647 goto end;
2648 }
2649
2650 nb_events = syscall_table_list(&events);
2651 if (nb_events < 0) {
2652 ret_code = (enum lttng_error_code) -nb_events;
2653 goto end;
2654 }
2655
2656 for (i = 0; i < nb_events; i++) {
2657 ret = lttng_event_serialize(&events[i], 0, NULL, NULL, 0, NULL,
2658 reply_payload);
2659 if (ret) {
2660 ret_code = LTTNG_ERR_NOMEM;
2661 goto end;
2662 }
2663 }
2664
2665 if (nb_events > UINT32_MAX) {
2666 ERR("Syscall count would overflow the syscall listing command's reply");
2667 ret_code = LTTNG_ERR_OVERFLOW;
2668 goto end;
2669 }
2670
2671 /* Update command reply header. */
2672 reply_command_header.count = (uint32_t) nb_events;
2673 memcpy(reply_payload->buffer.data + reply_command_header_offset, &reply_command_header,
2674 sizeof(reply_command_header));
2675
2676 ret_code = LTTNG_OK;
2677 end:
2678 free(events);
2679 return ret_code;
2680 }
2681
2682 /*
2683 * Command LTTNG_START_TRACE processed by the client thread.
2684 *
2685 * Called with session mutex held.
2686 */
2687 int cmd_start_trace(struct ltt_session *session)
2688 {
2689 enum lttng_error_code ret;
2690 unsigned long nb_chan = 0;
2691 struct ltt_kernel_session *ksession;
2692 struct ltt_ust_session *usess;
2693 const bool session_rotated_after_last_stop =
2694 session->rotated_after_last_stop;
2695 const bool session_cleared_after_last_stop =
2696 session->cleared_after_last_stop;
2697
2698 LTTNG_ASSERT(session);
2699
2700 /* Ease our life a bit ;) */
2701 ksession = session->kernel_session;
2702 usess = session->ust_session;
2703
2704 /* Is the session already started? */
2705 if (session->active) {
2706 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2707 /* Perform nothing */
2708 goto end;
2709 }
2710
2711 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2712 !session->current_trace_chunk) {
2713 /*
2714 * A rotation was launched while the session was stopped and
2715 * it has not been completed yet. It is not possible to start
2716 * the session since starting the session here would require a
2717 * rotation from "NULL" to a new trace chunk. That rotation
2718 * would overlap with the ongoing rotation, which is not
2719 * supported.
2720 */
2721 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2722 session->name);
2723 ret = LTTNG_ERR_ROTATION_PENDING;
2724 goto error;
2725 }
2726
2727 /*
2728 * Starting a session without channel is useless since after that it's not
2729 * possible to enable channel thus inform the client.
2730 */
2731 if (usess && usess->domain_global.channels) {
2732 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2733 }
2734 if (ksession) {
2735 nb_chan += ksession->channel_count;
2736 }
2737 if (!nb_chan) {
2738 ret = LTTNG_ERR_NO_CHANNEL;
2739 goto error;
2740 }
2741
2742 session->active = 1;
2743 session->rotated_after_last_stop = false;
2744 session->cleared_after_last_stop = false;
2745 if (session->output_traces && !session->current_trace_chunk) {
2746 if (!session->has_been_started) {
2747 struct lttng_trace_chunk *trace_chunk;
2748
2749 DBG("Creating initial trace chunk of session \"%s\"",
2750 session->name);
2751 trace_chunk = session_create_new_trace_chunk(
2752 session, NULL, NULL, NULL);
2753 if (!trace_chunk) {
2754 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2755 goto error;
2756 }
2757 LTTNG_ASSERT(!session->current_trace_chunk);
2758 ret = (lttng_error_code) session_set_trace_chunk(session, trace_chunk,
2759 NULL);
2760 lttng_trace_chunk_put(trace_chunk);
2761 if (ret) {
2762 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2763 goto error;
2764 }
2765 } else {
2766 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2767 session->name);
2768 /*
2769 * Rotate existing streams into the new chunk.
2770 * This is a "quiet" rotation has no client has
2771 * explicitly requested this operation.
2772 *
2773 * There is also no need to wait for the rotation
2774 * to complete as it will happen immediately. No data
2775 * was produced as the session was stopped, so the
2776 * rotation should happen on reception of the command.
2777 */
2778 ret = (lttng_error_code) cmd_rotate_session(session, NULL, true,
2779 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2780 if (ret != LTTNG_OK) {
2781 goto error;
2782 }
2783 }
2784 }
2785
2786 /* Kernel tracing */
2787 if (ksession != NULL) {
2788 DBG("Start kernel tracing session %s", session->name);
2789 ret = (lttng_error_code) start_kernel_session(ksession);
2790 if (ret != LTTNG_OK) {
2791 goto error;
2792 }
2793 }
2794
2795 /* Flag session that trace should start automatically */
2796 if (usess) {
2797 int int_ret = ust_app_start_trace_all(usess);
2798
2799 if (int_ret < 0) {
2800 ret = LTTNG_ERR_UST_START_FAIL;
2801 goto error;
2802 }
2803 }
2804
2805 /*
2806 * Open a packet in every stream of the session to ensure that viewers
2807 * can correctly identify the boundaries of the periods during which
2808 * tracing was active for this session.
2809 */
2810 ret = session_open_packets(session);
2811 if (ret != LTTNG_OK) {
2812 goto error;
2813 }
2814
2815 /*
2816 * Clear the flag that indicates that a rotation was done while the
2817 * session was stopped.
2818 */
2819 session->rotated_after_last_stop = false;
2820
2821 if (session->rotate_timer_period && !session->rotation_schedule_timer_enabled) {
2822 int int_ret = timer_session_rotation_schedule_timer_start(
2823 session, session->rotate_timer_period);
2824
2825 if (int_ret < 0) {
2826 ERR("Failed to enable rotate timer");
2827 ret = LTTNG_ERR_UNK;
2828 goto error;
2829 }
2830 }
2831
2832 ret = LTTNG_OK;
2833
2834 error:
2835 if (ret == LTTNG_OK) {
2836 /* Flag this after a successful start. */
2837 session->has_been_started |= 1;
2838 } else {
2839 session->active = 0;
2840 /* Restore initial state on error. */
2841 session->rotated_after_last_stop =
2842 session_rotated_after_last_stop;
2843 session->cleared_after_last_stop =
2844 session_cleared_after_last_stop;
2845 }
2846 end:
2847 return ret;
2848 }
2849
2850 /*
2851 * Command LTTNG_STOP_TRACE processed by the client thread.
2852 */
2853 int cmd_stop_trace(struct ltt_session *session)
2854 {
2855 int ret;
2856 struct ltt_kernel_session *ksession;
2857 struct ltt_ust_session *usess;
2858
2859 LTTNG_ASSERT(session);
2860
2861 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2862 /* Short cut */
2863 ksession = session->kernel_session;
2864 usess = session->ust_session;
2865
2866 /* Session is not active. Skip everything and inform the client. */
2867 if (!session->active) {
2868 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2869 goto error;
2870 }
2871
2872 ret = stop_kernel_session(ksession);
2873 if (ret != LTTNG_OK) {
2874 goto error;
2875 }
2876
2877 if (usess && usess->active) {
2878 ret = ust_app_stop_trace_all(usess);
2879 if (ret < 0) {
2880 ret = LTTNG_ERR_UST_STOP_FAIL;
2881 goto error;
2882 }
2883 }
2884
2885 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2886 session->id);
2887 /* Flag inactive after a successful stop. */
2888 session->active = 0;
2889 ret = LTTNG_OK;
2890
2891 error:
2892 return ret;
2893 }
2894
2895 /*
2896 * Set the base_path of the session only if subdir of a control uris is set.
2897 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2898 */
2899 static int set_session_base_path_from_uris(struct ltt_session *session,
2900 size_t nb_uri,
2901 struct lttng_uri *uris)
2902 {
2903 int ret;
2904 size_t i;
2905
2906 for (i = 0; i < nb_uri; i++) {
2907 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2908 uris[i].subdir[0] == '\0') {
2909 /* Not interested in these URIs */
2910 continue;
2911 }
2912
2913 if (session->base_path != NULL) {
2914 free(session->base_path);
2915 session->base_path = NULL;
2916 }
2917
2918 /* Set session base_path */
2919 session->base_path = strdup(uris[i].subdir);
2920 if (!session->base_path) {
2921 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2922 uris[i].subdir, session->name);
2923 ret = LTTNG_ERR_NOMEM;
2924 goto error;
2925 }
2926 DBG2("Setting base path \"%s\" for session \"%s\"",
2927 session->base_path, session->name);
2928 }
2929 ret = LTTNG_OK;
2930 error:
2931 return ret;
2932 }
2933
2934 /*
2935 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2936 */
2937 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2938 struct lttng_uri *uris)
2939 {
2940 int ret, i;
2941 struct ltt_kernel_session *ksess = session->kernel_session;
2942 struct ltt_ust_session *usess = session->ust_session;
2943
2944 LTTNG_ASSERT(session);
2945 LTTNG_ASSERT(uris);
2946 LTTNG_ASSERT(nb_uri > 0);
2947
2948 /* Can't set consumer URI if the session is active. */
2949 if (session->active) {
2950 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2951 goto error;
2952 }
2953
2954 /*
2955 * Set the session base path if any. This is done inside
2956 * cmd_set_consumer_uri to preserve backward compatibility of the
2957 * previous session creation api vs the session descriptor api.
2958 */
2959 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2960 if (ret != LTTNG_OK) {
2961 goto error;
2962 }
2963
2964 /* Set the "global" consumer URIs */
2965 for (i = 0; i < nb_uri; i++) {
2966 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2967 LTTNG_DOMAIN_NONE);
2968 if (ret != LTTNG_OK) {
2969 goto error;
2970 }
2971 }
2972
2973 /* Set UST session URIs */
2974 if (session->ust_session) {
2975 for (i = 0; i < nb_uri; i++) {
2976 ret = add_uri_to_consumer(session,
2977 session->ust_session->consumer,
2978 &uris[i], LTTNG_DOMAIN_UST);
2979 if (ret != LTTNG_OK) {
2980 goto error;
2981 }
2982 }
2983 }
2984
2985 /* Set kernel session URIs */
2986 if (session->kernel_session) {
2987 for (i = 0; i < nb_uri; i++) {
2988 ret = add_uri_to_consumer(session,
2989 session->kernel_session->consumer,
2990 &uris[i], LTTNG_DOMAIN_KERNEL);
2991 if (ret != LTTNG_OK) {
2992 goto error;
2993 }
2994 }
2995 }
2996
2997 /*
2998 * Make sure to set the session in output mode after we set URI since a
2999 * session can be created without URL (thus flagged in no output mode).
3000 */
3001 session->output_traces = 1;
3002 if (ksess) {
3003 ksess->output_traces = 1;
3004 }
3005
3006 if (usess) {
3007 usess->output_traces = 1;
3008 }
3009
3010 /* All good! */
3011 ret = LTTNG_OK;
3012
3013 error:
3014 return ret;
3015 }
3016
3017 static
3018 enum lttng_error_code set_session_output_from_descriptor(
3019 struct ltt_session *session,
3020 const struct lttng_session_descriptor *descriptor)
3021 {
3022 int ret;
3023 enum lttng_error_code ret_code = LTTNG_OK;
3024 enum lttng_session_descriptor_type session_type =
3025 lttng_session_descriptor_get_type(descriptor);
3026 enum lttng_session_descriptor_output_type output_type =
3027 lttng_session_descriptor_get_output_type(descriptor);
3028 struct lttng_uri uris[2] = {};
3029 size_t uri_count = 0;
3030
3031 switch (output_type) {
3032 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
3033 goto end;
3034 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
3035 lttng_session_descriptor_get_local_output_uri(descriptor,
3036 &uris[0]);
3037 uri_count = 1;
3038 break;
3039 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
3040 lttng_session_descriptor_get_network_output_uris(descriptor,
3041 &uris[0], &uris[1]);
3042 uri_count = 2;
3043 break;
3044 default:
3045 ret_code = LTTNG_ERR_INVALID;
3046 goto end;
3047 }
3048
3049 switch (session_type) {
3050 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3051 {
3052 struct snapshot_output *new_output = NULL;
3053
3054 new_output = snapshot_output_alloc();
3055 if (!new_output) {
3056 ret_code = LTTNG_ERR_NOMEM;
3057 goto end;
3058 }
3059
3060 ret = snapshot_output_init_with_uri(session,
3061 DEFAULT_SNAPSHOT_MAX_SIZE,
3062 NULL, uris, uri_count, session->consumer,
3063 new_output, &session->snapshot);
3064 if (ret < 0) {
3065 ret_code = (ret == -ENOMEM) ?
3066 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
3067 snapshot_output_destroy(new_output);
3068 goto end;
3069 }
3070 snapshot_add_output(&session->snapshot, new_output);
3071 break;
3072 }
3073 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3074 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3075 {
3076 ret_code = (lttng_error_code) cmd_set_consumer_uri(session, uri_count, uris);
3077 break;
3078 }
3079 default:
3080 ret_code = LTTNG_ERR_INVALID;
3081 goto end;
3082 }
3083 end:
3084 return ret_code;
3085 }
3086
3087 static
3088 enum lttng_error_code cmd_create_session_from_descriptor(
3089 struct lttng_session_descriptor *descriptor,
3090 const lttng_sock_cred *creds,
3091 const char *home_path)
3092 {
3093 int ret;
3094 enum lttng_error_code ret_code;
3095 const char *session_name;
3096 struct ltt_session *new_session = NULL;
3097 enum lttng_session_descriptor_status descriptor_status;
3098
3099 session_lock_list();
3100 if (home_path) {
3101 if (*home_path != '/') {
3102 ERR("Home path provided by client is not absolute");
3103 ret_code = LTTNG_ERR_INVALID;
3104 goto end;
3105 }
3106 }
3107
3108 descriptor_status = lttng_session_descriptor_get_session_name(
3109 descriptor, &session_name);
3110 switch (descriptor_status) {
3111 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3112 break;
3113 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3114 session_name = NULL;
3115 break;
3116 default:
3117 ret_code = LTTNG_ERR_INVALID;
3118 goto end;
3119 }
3120
3121 ret_code = session_create(session_name, creds->uid, creds->gid,
3122 &new_session);
3123 if (ret_code != LTTNG_OK) {
3124 goto end;
3125 }
3126
3127 if (!session_name) {
3128 ret = lttng_session_descriptor_set_session_name(descriptor,
3129 new_session->name);
3130 if (ret) {
3131 ret_code = LTTNG_ERR_SESSION_FAIL;
3132 goto end;
3133 }
3134 }
3135
3136 if (!lttng_session_descriptor_is_output_destination_initialized(
3137 descriptor)) {
3138 /*
3139 * Only include the session's creation time in the output
3140 * destination if the name of the session itself was
3141 * not auto-generated.
3142 */
3143 ret_code = lttng_session_descriptor_set_default_output(
3144 descriptor,
3145 session_name ? &new_session->creation_time : NULL,
3146 home_path);
3147 if (ret_code != LTTNG_OK) {
3148 goto end;
3149 }
3150 } else {
3151 new_session->has_user_specified_directory =
3152 lttng_session_descriptor_has_output_directory(
3153 descriptor);
3154 }
3155
3156 switch (lttng_session_descriptor_get_type(descriptor)) {
3157 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3158 new_session->snapshot_mode = 1;
3159 break;
3160 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3161 new_session->live_timer =
3162 lttng_session_descriptor_live_get_timer_interval(
3163 descriptor);
3164 break;
3165 default:
3166 break;
3167 }
3168
3169 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3170 if (ret_code != LTTNG_OK) {
3171 goto end;
3172 }
3173 new_session->consumer->enabled = 1;
3174 ret_code = LTTNG_OK;
3175 end:
3176 /* Release reference provided by the session_create function. */
3177 session_put(new_session);
3178 if (ret_code != LTTNG_OK && new_session) {
3179 /* Release the global reference on error. */
3180 session_destroy(new_session);
3181 }
3182 session_unlock_list();
3183 return ret_code;
3184 }
3185
3186 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3187 struct lttng_session_descriptor **return_descriptor)
3188 {
3189 int ret;
3190 size_t payload_size;
3191 struct lttng_dynamic_buffer payload;
3192 struct lttng_buffer_view home_dir_view;
3193 struct lttng_buffer_view session_descriptor_view;
3194 struct lttng_session_descriptor *session_descriptor = NULL;
3195 enum lttng_error_code ret_code;
3196
3197 lttng_dynamic_buffer_init(&payload);
3198 if (cmd_ctx->lsm.u.create_session.home_dir_size >=
3199 LTTNG_PATH_MAX) {
3200 ret_code = LTTNG_ERR_INVALID;
3201 goto error;
3202 }
3203 if (cmd_ctx->lsm.u.create_session.session_descriptor_size >
3204 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3205 ret_code = LTTNG_ERR_INVALID;
3206 goto error;
3207 }
3208
3209 payload_size = cmd_ctx->lsm.u.create_session.home_dir_size +
3210 cmd_ctx->lsm.u.create_session.session_descriptor_size;
3211 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3212 if (ret) {
3213 ret_code = LTTNG_ERR_NOMEM;
3214 goto error;
3215 }
3216
3217 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3218 if (ret <= 0) {
3219 ERR("Reception of session descriptor failed, aborting.");
3220 ret_code = LTTNG_ERR_SESSION_FAIL;
3221 goto error;
3222 }
3223
3224 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3225 &payload,
3226 0,
3227 cmd_ctx->lsm.u.create_session.home_dir_size);
3228 if (cmd_ctx->lsm.u.create_session.home_dir_size > 0 &&
3229 !lttng_buffer_view_is_valid(&home_dir_view)) {
3230 ERR("Invalid payload in \"create session\" command: buffer too short to contain home directory");
3231 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3232 goto error;
3233 }
3234
3235 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3236 &payload,
3237 cmd_ctx->lsm.u.create_session.home_dir_size,
3238 cmd_ctx->lsm.u.create_session.session_descriptor_size);
3239 if (!lttng_buffer_view_is_valid(&session_descriptor_view)) {
3240 ERR("Invalid payload in \"create session\" command: buffer too short to contain session descriptor");
3241 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3242 goto error;
3243 }
3244
3245 ret = lttng_session_descriptor_create_from_buffer(
3246 &session_descriptor_view, &session_descriptor);
3247 if (ret < 0) {
3248 ERR("Failed to create session descriptor from payload of \"create session\" command");
3249 ret_code = LTTNG_ERR_INVALID;
3250 goto error;
3251 }
3252
3253 /*
3254 * Sets the descriptor's auto-generated properties (name, output) if
3255 * needed.
3256 */
3257 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3258 &cmd_ctx->creds,
3259 home_dir_view.size ? home_dir_view.data : NULL);
3260 if (ret_code != LTTNG_OK) {
3261 goto error;
3262 }
3263
3264 ret_code = LTTNG_OK;
3265 *return_descriptor = session_descriptor;
3266 session_descriptor = NULL;
3267 error:
3268 lttng_dynamic_buffer_reset(&payload);
3269 lttng_session_descriptor_destroy(session_descriptor);
3270 return ret_code;
3271 }
3272
3273 static
3274 void cmd_destroy_session_reply(const struct ltt_session *session,
3275 void *_reply_context)
3276 {
3277 int ret;
3278 ssize_t comm_ret;
3279 const struct cmd_destroy_session_reply_context *reply_context =
3280 (cmd_destroy_session_reply_context *) _reply_context;
3281 struct lttng_dynamic_buffer payload;
3282 struct lttcomm_session_destroy_command_header cmd_header;
3283 struct lttng_trace_archive_location *location = NULL;
3284 struct lttcomm_lttng_msg llm = {
3285 .cmd_type = LTTNG_DESTROY_SESSION,
3286 .ret_code = reply_context->destruction_status,
3287 .pid = UINT32_MAX,
3288 .cmd_header_size =
3289 sizeof(struct lttcomm_session_destroy_command_header),
3290 .data_size = 0,
3291 };
3292 size_t payload_size_before_location;
3293
3294 lttng_dynamic_buffer_init(&payload);
3295
3296 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3297 if (ret) {
3298 ERR("Failed to append session destruction message");
3299 goto error;
3300 }
3301
3302 cmd_header.rotation_state =
3303 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3304 session->rotation_state :
3305 LTTNG_ROTATION_STATE_NO_ROTATION);
3306 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3307 sizeof(cmd_header));
3308 if (ret) {
3309 ERR("Failed to append session destruction command header");
3310 goto error;
3311 }
3312
3313 if (!reply_context->implicit_rotation_on_destroy) {
3314 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3315 session->name);
3316 goto send_reply;
3317 }
3318 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3319 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3320 session->name);
3321 goto send_reply;
3322 }
3323
3324 location = session_get_trace_archive_location(session);
3325 if (!location) {
3326 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3327 session->name);
3328 goto error;
3329 }
3330
3331 payload_size_before_location = payload.size;
3332 comm_ret = lttng_trace_archive_location_serialize(location,
3333 &payload);
3334 lttng_trace_archive_location_put(location);
3335 if (comm_ret < 0) {
3336 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3337 session->name);
3338 goto error;
3339 }
3340 /* Update the message to indicate the location's length. */
3341 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3342 payload.size - payload_size_before_location;
3343 send_reply:
3344 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3345 payload.data, payload.size);
3346 if (comm_ret != (ssize_t) payload.size) {
3347 ERR("Failed to send result of the destruction of session \"%s\" to client",
3348 session->name);
3349 }
3350 error:
3351 ret = close(reply_context->reply_sock_fd);
3352 if (ret) {
3353 PERROR("Failed to close client socket in deferred session destroy reply");
3354 }
3355 lttng_dynamic_buffer_reset(&payload);
3356 free(_reply_context);
3357 }
3358
3359 /*
3360 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3361 *
3362 * Called with session lock held.
3363 */
3364 int cmd_destroy_session(struct ltt_session *session,
3365 struct notification_thread_handle *notification_thread_handle,
3366 int *sock_fd)
3367 {
3368 int ret;
3369 enum lttng_error_code destruction_last_error = LTTNG_OK;
3370 struct cmd_destroy_session_reply_context *reply_context = NULL;
3371
3372 if (sock_fd) {
3373 reply_context = (cmd_destroy_session_reply_context *) zmalloc(sizeof(*reply_context));
3374 if (!reply_context) {
3375 ret = LTTNG_ERR_NOMEM;
3376 goto end;
3377 }
3378 reply_context->reply_sock_fd = *sock_fd;
3379 }
3380
3381 /* Safety net */
3382 LTTNG_ASSERT(session);
3383
3384 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3385 session->id);
3386 if (session->active) {
3387 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3388 session->name);
3389 ret = cmd_stop_trace(session);
3390 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3391 /* Carry on with the destruction of the session. */
3392 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3393 session->name, lttng_strerror(-ret));
3394 destruction_last_error = (lttng_error_code) ret;
3395 }
3396 }
3397
3398 if (session->rotation_schedule_timer_enabled) {
3399 if (timer_session_rotation_schedule_timer_stop(
3400 session)) {
3401 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3402 session->name);
3403 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3404 }
3405 }
3406
3407 if (session->rotate_size) {
3408 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3409 session->rotate_size = 0;
3410 }
3411
3412 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3413 /*
3414 * Perform a last rotation on destruction if rotations have
3415 * occurred during the session's lifetime.
3416 */
3417 ret = cmd_rotate_session(session, NULL, false,
3418 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3419 if (ret != LTTNG_OK) {
3420 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3421 session->name, lttng_strerror(-ret));
3422 destruction_last_error = (lttng_error_code) -ret;
3423 }
3424 if (reply_context) {
3425 reply_context->implicit_rotation_on_destroy = true;
3426 }
3427 } else if (session->has_been_started && session->current_trace_chunk) {
3428 /*
3429 * The user has not triggered a session rotation. However, to
3430 * ensure all data has been consumed, the session is rotated
3431 * to a 'null' trace chunk before it is destroyed.
3432 *
3433 * This is a "quiet" rotation meaning that no notification is
3434 * emitted and no renaming of the current trace chunk takes
3435 * place.
3436 */
3437 ret = cmd_rotate_session(session, NULL, true,
3438 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3439 /*
3440 * Rotation operations may not be supported by the kernel
3441 * tracer. Hence, do not consider this implicit rotation as
3442 * a session destruction error. The library has already stopped
3443 * the session and waited for pending data; there is nothing
3444 * left to do but complete the destruction of the session.
3445 */
3446 if (ret != LTTNG_OK &&
3447 ret != -LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL) {
3448 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3449 session->name, lttng_strerror(ret));
3450 destruction_last_error = (lttng_error_code) -ret;
3451 }
3452 }
3453
3454 if (session->shm_path[0]) {
3455 /*
3456 * When a session is created with an explicit shm_path,
3457 * the consumer daemon will create its shared memory files
3458 * at that location and will *not* unlink them. This is normal
3459 * as the intention of that feature is to make it possible
3460 * to retrieve the content of those files should a crash occur.
3461 *
3462 * To ensure the content of those files can be used, the
3463 * sessiond daemon will replicate the content of the metadata
3464 * cache in a metadata file.
3465 *
3466 * On clean-up, it is expected that the consumer daemon will
3467 * unlink the shared memory files and that the session daemon
3468 * will unlink the metadata file. Then, the session's directory
3469 * in the shm path can be removed.
3470 *
3471 * Unfortunately, a flaw in the design of the sessiond's and
3472 * consumerd's tear down of channels makes it impossible to
3473 * determine when the sessiond _and_ the consumerd have both
3474 * destroyed their representation of a channel. For one, the
3475 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3476 * callbacks in both daemons.
3477 *
3478 * However, it is also impossible for the sessiond to know when
3479 * the consumer daemon is done destroying its channel(s) since
3480 * it occurs as a reaction to the closing of the channel's file
3481 * descriptor. There is no resulting communication initiated
3482 * from the consumerd to the sessiond to confirm that the
3483 * operation is completed (and was successful).
3484 *
3485 * Until this is all fixed, the session daemon checks for the
3486 * removal of the session's shm path which makes it possible
3487 * to safely advertise a session as having been destroyed.
3488 *
3489 * Prior to this fix, it was not possible to reliably save
3490 * a session making use of the --shm-path option, destroy it,
3491 * and load it again. This is because the creation of the
3492 * session would fail upon seeing the session's shm path
3493 * already in existence.
3494 *
3495 * Note that none of the error paths in the check for the
3496 * directory's existence return an error. This is normal
3497 * as there isn't much that can be done. The session will
3498 * be destroyed properly, except that we can't offer the
3499 * guarantee that the same session can be re-created.
3500 */
3501 current_completion_handler = &destroy_completion_handler.handler;
3502 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3503 session->shm_path,
3504 sizeof(destroy_completion_handler.shm_path));
3505 LTTNG_ASSERT(!ret);
3506 }
3507
3508 /*
3509 * The session is destroyed. However, note that the command context
3510 * still holds a reference to the session, thus delaying its destruction
3511 * _at least_ up to the point when that reference is released.
3512 */
3513 session_destroy(session);
3514 if (reply_context) {
3515 reply_context->destruction_status = destruction_last_error;
3516 ret = session_add_destroy_notifier(session,
3517 cmd_destroy_session_reply,
3518 (void *) reply_context);
3519 if (ret) {
3520 ret = LTTNG_ERR_FATAL;
3521 goto end;
3522 } else {
3523 *sock_fd = -1;
3524 }
3525 }
3526 ret = LTTNG_OK;
3527 end:
3528 return ret;
3529 }
3530
3531 /*
3532 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3533 */
3534 int cmd_register_consumer(struct ltt_session *session,
3535 enum lttng_domain_type domain, const char *sock_path,
3536 struct consumer_data *cdata)
3537 {
3538 int ret, sock;
3539 struct consumer_socket *socket = NULL;
3540
3541 LTTNG_ASSERT(session);
3542 LTTNG_ASSERT(cdata);
3543 LTTNG_ASSERT(sock_path);
3544
3545 switch (domain) {
3546 case LTTNG_DOMAIN_KERNEL:
3547 {
3548 struct ltt_kernel_session *ksess = session->kernel_session;
3549
3550 LTTNG_ASSERT(ksess);
3551
3552 /* Can't register a consumer if there is already one */
3553 if (ksess->consumer_fds_sent != 0) {
3554 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3555 goto error;
3556 }
3557
3558 sock = lttcomm_connect_unix_sock(sock_path);
3559 if (sock < 0) {
3560 ret = LTTNG_ERR_CONNECT_FAIL;
3561 goto error;
3562 }
3563 cdata->cmd_sock = sock;
3564
3565 socket = consumer_allocate_socket(&cdata->cmd_sock);
3566 if (socket == NULL) {
3567 ret = close(sock);
3568 if (ret < 0) {
3569 PERROR("close register consumer");
3570 }
3571 cdata->cmd_sock = -1;
3572 ret = LTTNG_ERR_FATAL;
3573 goto error;
3574 }
3575
3576 socket->lock = (pthread_mutex_t *) zmalloc(sizeof(pthread_mutex_t));
3577 if (socket->lock == NULL) {
3578 PERROR("zmalloc pthread mutex");
3579 ret = LTTNG_ERR_FATAL;
3580 goto error;
3581 }
3582 pthread_mutex_init(socket->lock, NULL);
3583 socket->registered = 1;
3584
3585 rcu_read_lock();
3586 consumer_add_socket(socket, ksess->consumer);
3587 rcu_read_unlock();
3588
3589 pthread_mutex_lock(&cdata->pid_mutex);
3590 cdata->pid = -1;
3591 pthread_mutex_unlock(&cdata->pid_mutex);
3592
3593 break;
3594 }
3595 default:
3596 /* TODO: Userspace tracing */
3597 ret = LTTNG_ERR_UND;
3598 goto error;
3599 }
3600
3601 return LTTNG_OK;
3602
3603 error:
3604 if (socket) {
3605 consumer_destroy_socket(socket);
3606 }
3607 return ret;
3608 }
3609
3610 /*
3611 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3612 */
3613 ssize_t cmd_list_domains(struct ltt_session *session,
3614 struct lttng_domain **domains)
3615 {
3616 int ret, index = 0;
3617 ssize_t nb_dom = 0;
3618 struct agent *agt;
3619 struct lttng_ht_iter iter;
3620
3621 if (session->kernel_session != NULL) {
3622 DBG3("Listing domains found kernel domain");
3623 nb_dom++;
3624 }
3625
3626 if (session->ust_session != NULL) {
3627 DBG3("Listing domains found UST global domain");
3628 nb_dom++;
3629
3630 rcu_read_lock();
3631 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3632 agt, node.node) {
3633 if (agt->being_used) {
3634 nb_dom++;
3635 }
3636 }
3637 rcu_read_unlock();
3638 }
3639
3640 if (!nb_dom) {
3641 goto end;
3642 }
3643
3644 *domains = (lttng_domain *) zmalloc(nb_dom * sizeof(struct lttng_domain));
3645 if (*domains == NULL) {
3646 ret = LTTNG_ERR_FATAL;
3647 goto error;
3648 }
3649
3650 if (session->kernel_session != NULL) {
3651 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3652
3653 /* Kernel session buffer type is always GLOBAL */
3654 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3655
3656 index++;
3657 }
3658
3659 if (session->ust_session != NULL) {
3660 (*domains)[index].type = LTTNG_DOMAIN_UST;
3661 (*domains)[index].buf_type = session->ust_session->buffer_type;
3662 index++;
3663
3664 rcu_read_lock();
3665 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3666 agt, node.node) {
3667 if (agt->being_used) {
3668 (*domains)[index].type = agt->domain;
3669 (*domains)[index].buf_type = session->ust_session->buffer_type;
3670 index++;
3671 }
3672 }
3673 rcu_read_unlock();
3674 }
3675 end:
3676 return nb_dom;
3677
3678 error:
3679 /* Return negative value to differentiate return code */
3680 return -ret;
3681 }
3682
3683
3684 /*
3685 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3686 */
3687 enum lttng_error_code cmd_list_channels(enum lttng_domain_type domain,
3688 struct ltt_session *session,
3689 struct lttng_payload *payload)
3690 {
3691 int ret = 0;
3692 unsigned int i = 0;
3693 struct lttcomm_list_command_header cmd_header = {};
3694 size_t cmd_header_offset;
3695 enum lttng_error_code ret_code;
3696
3697 assert(session);
3698 assert(payload);
3699
3700 DBG("Listing channels for session %s", session->name);
3701
3702 cmd_header_offset = payload->buffer.size;
3703
3704 /* Reserve space for command reply header. */
3705 ret = lttng_dynamic_buffer_set_size(&payload->buffer,
3706 cmd_header_offset + sizeof(cmd_header));
3707 if (ret) {
3708 ret_code = LTTNG_ERR_NOMEM;
3709 goto end;
3710 }
3711
3712 switch (domain) {
3713 case LTTNG_DOMAIN_KERNEL:
3714 {
3715 /* Kernel channels */
3716 struct ltt_kernel_channel *kchan;
3717 if (session->kernel_session != NULL) {
3718 cds_list_for_each_entry(kchan,
3719 &session->kernel_session->channel_list.head, list) {
3720 uint64_t discarded_events, lost_packets;
3721 struct lttng_channel_extended *extended;
3722
3723 extended = (struct lttng_channel_extended *)
3724 kchan->channel->attr.extended.ptr;
3725
3726 ret = get_kernel_runtime_stats(session, kchan,
3727 &discarded_events, &lost_packets);
3728 if (ret < 0) {
3729 ret_code = LTTNG_ERR_UNK;
3730 goto end;
3731 }
3732
3733 /*
3734 * Update the discarded_events and lost_packets
3735 * count for the channel
3736 */
3737 extended->discarded_events = discarded_events;
3738 extended->lost_packets = lost_packets;
3739
3740 ret = lttng_channel_serialize(
3741 kchan->channel, &payload->buffer);
3742 if (ret) {
3743 ERR("Failed to serialize lttng_channel: channel name = '%s'",
3744 kchan->channel->name);
3745 ret_code = LTTNG_ERR_UNK;
3746 goto end;
3747 }
3748
3749 i++;
3750 }
3751 }
3752 break;
3753 }
3754 case LTTNG_DOMAIN_UST:
3755 {
3756 struct lttng_ht_iter iter;
3757 struct ltt_ust_channel *uchan;
3758
3759 rcu_read_lock();
3760 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
3761 &iter.iter, uchan, node.node) {
3762 uint64_t discarded_events = 0, lost_packets = 0;
3763 struct lttng_channel *channel = NULL;
3764 struct lttng_channel_extended *extended;
3765
3766 channel = trace_ust_channel_to_lttng_channel(uchan);
3767 if (!channel) {
3768 ret_code = LTTNG_ERR_NOMEM;
3769 goto end;
3770 }
3771
3772 extended = (struct lttng_channel_extended *)
3773 channel->attr.extended.ptr;
3774
3775 ret = get_ust_runtime_stats(session, uchan,
3776 &discarded_events, &lost_packets);
3777 if (ret < 0) {
3778 lttng_channel_destroy(channel);
3779 ret_code = LTTNG_ERR_UNK;
3780 goto end;
3781 }
3782
3783 extended->discarded_events = discarded_events;
3784 extended->lost_packets = lost_packets;
3785
3786 ret = lttng_channel_serialize(
3787 channel, &payload->buffer);
3788 if (ret) {
3789 ERR("Failed to serialize lttng_channel: channel name = '%s'",
3790 channel->name);
3791 lttng_channel_destroy(channel);
3792 ret_code = LTTNG_ERR_UNK;
3793 goto end;
3794 }
3795
3796 lttng_channel_destroy(channel);
3797 i++;
3798 }
3799 rcu_read_unlock();
3800 break;
3801 }
3802 default:
3803 break;
3804 }
3805
3806 if (i > UINT32_MAX) {
3807 ERR("Channel count would overflow the channel listing command's reply");
3808 ret_code = LTTNG_ERR_OVERFLOW;
3809 goto end;
3810 }
3811
3812 /* Update command reply header. */
3813 cmd_header.count = (uint32_t) i;
3814 memcpy(payload->buffer.data + cmd_header_offset, &cmd_header,
3815 sizeof(cmd_header));
3816 ret_code = LTTNG_OK;
3817
3818 end:
3819 return ret_code;
3820 }
3821
3822 /*
3823 * Command LTTNG_LIST_EVENTS processed by the client thread.
3824 */
3825 enum lttng_error_code cmd_list_events(enum lttng_domain_type domain,
3826 struct ltt_session *session,
3827 char *channel_name,
3828 struct lttng_payload *reply_payload)
3829 {
3830 int buffer_resize_ret;
3831 enum lttng_error_code ret_code = LTTNG_OK;
3832 struct lttcomm_list_command_header reply_command_header = {};
3833 size_t reply_command_header_offset;
3834 unsigned int nb_events = 0;
3835
3836 assert(reply_payload);
3837
3838 /* Reserve space for command reply header. */
3839 reply_command_header_offset = reply_payload->buffer.size;
3840 buffer_resize_ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
3841 reply_command_header_offset +
3842 sizeof(struct lttcomm_list_command_header));
3843 if (buffer_resize_ret) {
3844 ret_code = LTTNG_ERR_NOMEM;
3845 goto end;
3846 }
3847
3848 switch (domain) {
3849 case LTTNG_DOMAIN_KERNEL:
3850 if (session->kernel_session != NULL) {
3851 ret_code = list_lttng_kernel_events(channel_name,
3852 session->kernel_session, reply_payload, &nb_events);
3853 }
3854
3855 break;
3856 case LTTNG_DOMAIN_UST:
3857 {
3858 if (session->ust_session != NULL) {
3859 ret_code = list_lttng_ust_global_events(channel_name,
3860 &session->ust_session->domain_global,
3861 reply_payload, &nb_events);
3862 }
3863
3864 break;
3865 }
3866 case LTTNG_DOMAIN_LOG4J:
3867 case LTTNG_DOMAIN_JUL:
3868 case LTTNG_DOMAIN_PYTHON:
3869 if (session->ust_session) {
3870 struct lttng_ht_iter iter;
3871 struct agent *agt;
3872
3873 rcu_read_lock();
3874 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3875 &iter.iter, agt, node.node) {
3876 if (agt->domain == domain) {
3877 ret_code = list_lttng_agent_events(
3878 agt, reply_payload, &nb_events);
3879 break;
3880 }
3881 }
3882
3883 rcu_read_unlock();
3884 }
3885 break;
3886 default:
3887 ret_code = LTTNG_ERR_UND;
3888 break;
3889 }
3890
3891 if (nb_events > UINT32_MAX) {
3892 ret_code = LTTNG_ERR_OVERFLOW;
3893 goto end;
3894 }
3895
3896 /* Update command reply header. */
3897 reply_command_header.count = (uint32_t) nb_events;
3898 memcpy(reply_payload->buffer.data + reply_command_header_offset, &reply_command_header,
3899 sizeof(reply_command_header));
3900
3901 end:
3902 return ret_code;
3903 }
3904
3905 /*
3906 * Using the session list, filled a lttng_session array to send back to the
3907 * client for session listing.
3908 *
3909 * The session list lock MUST be acquired before calling this function. Use
3910 * session_lock_list() and session_unlock_list().
3911 */
3912 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3913 size_t session_count, uid_t uid, gid_t gid)
3914 {
3915 int ret;
3916 unsigned int i = 0;
3917 struct ltt_session *session;
3918 struct ltt_session_list *list = session_get_list();
3919 struct lttng_session_extended *extended =
3920 (typeof(extended)) (&sessions[session_count]);
3921
3922 DBG("Getting all available session for UID %d GID %d",
3923 uid, gid);
3924 /*
3925 * Iterate over session list and append data after the control struct in
3926 * the buffer.
3927 */
3928 cds_list_for_each_entry(session, &list->head, list) {
3929 if (!session_get(session)) {
3930 continue;
3931 }
3932 /*
3933 * Only list the sessions the user can control.
3934 */
3935 if (!session_access_ok(session, uid) ||
3936 session->destroyed) {
3937 session_put(session);
3938 continue;
3939 }
3940
3941 struct ltt_kernel_session *ksess = session->kernel_session;
3942 struct ltt_ust_session *usess = session->ust_session;
3943
3944 if (session->consumer->type == CONSUMER_DST_NET ||
3945 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3946 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3947 ret = build_network_session_path(sessions[i].path,
3948 sizeof(sessions[i].path), session);
3949 } else {
3950 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3951 session->consumer->dst.session_root_path);
3952 }
3953 if (ret < 0) {
3954 PERROR("snprintf session path");
3955 session_put(session);
3956 continue;
3957 }
3958
3959 strncpy(sessions[i].name, session->name, NAME_MAX);
3960 sessions[i].name[NAME_MAX - 1] = '\0';
3961 sessions[i].enabled = session->active;
3962 sessions[i].snapshot_mode = session->snapshot_mode;
3963 sessions[i].live_timer_interval = session->live_timer;
3964 extended[i].creation_time.value = (uint64_t) session->creation_time;
3965 extended[i].creation_time.is_set = 1;
3966 i++;
3967 session_put(session);
3968 }
3969 }
3970
3971 /*
3972 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3973 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3974 */
3975 int cmd_data_pending(struct ltt_session *session)
3976 {
3977 int ret;
3978 struct ltt_kernel_session *ksess = session->kernel_session;
3979 struct ltt_ust_session *usess = session->ust_session;
3980
3981 LTTNG_ASSERT(session);
3982
3983 DBG("Data pending for session %s", session->name);
3984
3985 /* Session MUST be stopped to ask for data availability. */
3986 if (session->active) {
3987 ret = LTTNG_ERR_SESSION_STARTED;
3988 goto error;
3989 } else {
3990 /*
3991 * If stopped, just make sure we've started before else the above call
3992 * will always send that there is data pending.
3993 *
3994 * The consumer assumes that when the data pending command is received,
3995 * the trace has been started before or else no output data is written
3996 * by the streams which is a condition for data pending. So, this is
3997 * *VERY* important that we don't ask the consumer before a start
3998 * trace.
3999 */
4000 if (!session->has_been_started) {
4001 ret = 0;
4002 goto error;
4003 }
4004 }
4005
4006 /* A rotation is still pending, we have to wait. */
4007 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
4008 DBG("Rotate still pending for session %s", session->name);
4009 ret = 1;
4010 goto error;
4011 }
4012
4013 if (ksess && ksess->consumer) {
4014 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
4015 if (ret == 1) {
4016 /* Data is still being extracted for the kernel. */
4017 goto error;
4018 }
4019 }
4020
4021 if (usess && usess->consumer) {
4022 ret = consumer_is_data_pending(usess->id, usess->consumer);
4023 if (ret == 1) {
4024 /* Data is still being extracted for the kernel. */
4025 goto error;
4026 }
4027 }
4028
4029 /* Data is ready to be read by a viewer */
4030 ret = 0;
4031
4032 error:
4033 return ret;
4034 }
4035
4036 /*
4037 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
4038 *
4039 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4040 */
4041 int cmd_snapshot_add_output(struct ltt_session *session,
4042 const struct lttng_snapshot_output *output, uint32_t *id)
4043 {
4044 int ret;
4045 struct snapshot_output *new_output;
4046
4047 LTTNG_ASSERT(session);
4048 LTTNG_ASSERT(output);
4049
4050 DBG("Cmd snapshot add output for session %s", session->name);
4051
4052 /*
4053 * Can't create an output if the session is not set in no-output mode.
4054 */
4055 if (session->output_traces) {
4056 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4057 goto error;
4058 }
4059
4060 if (session->has_non_mmap_channel) {
4061 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
4062 goto error;
4063 }
4064
4065 /* Only one output is allowed until we have the "tee" feature. */
4066 if (session->snapshot.nb_output == 1) {
4067 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
4068 goto error;
4069 }
4070
4071 new_output = snapshot_output_alloc();
4072 if (!new_output) {
4073 ret = LTTNG_ERR_NOMEM;
4074 goto error;
4075 }
4076
4077 ret = snapshot_output_init(session, output->max_size, output->name,
4078 output->ctrl_url, output->data_url, session->consumer, new_output,
4079 &session->snapshot);
4080 if (ret < 0) {
4081 if (ret == -ENOMEM) {
4082 ret = LTTNG_ERR_NOMEM;
4083 } else {
4084 ret = LTTNG_ERR_INVALID;
4085 }
4086 goto free_error;
4087 }
4088
4089 rcu_read_lock();
4090 snapshot_add_output(&session->snapshot, new_output);
4091 if (id) {
4092 *id = new_output->id;
4093 }
4094 rcu_read_unlock();
4095
4096 return LTTNG_OK;
4097
4098 free_error:
4099 snapshot_output_destroy(new_output);
4100 error:
4101 return ret;
4102 }
4103
4104 /*
4105 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
4106 *
4107 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4108 */
4109 int cmd_snapshot_del_output(struct ltt_session *session,
4110 const struct lttng_snapshot_output *output)
4111 {
4112 int ret;
4113 struct snapshot_output *sout = NULL;
4114
4115 LTTNG_ASSERT(session);
4116 LTTNG_ASSERT(output);
4117
4118 rcu_read_lock();
4119
4120 /*
4121 * Permission denied to create an output if the session is not
4122 * set in no output mode.
4123 */
4124 if (session->output_traces) {
4125 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4126 goto error;
4127 }
4128
4129 if (output->id) {
4130 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
4131 session->name);
4132 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
4133 } else if (*output->name != '\0') {
4134 DBG("Cmd snapshot del output name %s for session %s", output->name,
4135 session->name);
4136 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
4137 }
4138 if (!sout) {
4139 ret = LTTNG_ERR_INVALID;
4140 goto error;
4141 }
4142
4143 snapshot_delete_output(&session->snapshot, sout);
4144 snapshot_output_destroy(sout);
4145 ret = LTTNG_OK;
4146
4147 error:
4148 rcu_read_unlock();
4149 return ret;
4150 }
4151
4152 /*
4153 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
4154 *
4155 * If no output is available, outputs is untouched and 0 is returned.
4156 *
4157 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
4158 */
4159 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
4160 struct lttng_snapshot_output **outputs)
4161 {
4162 int ret, idx = 0;
4163 struct lttng_snapshot_output *list = NULL;
4164 struct lttng_ht_iter iter;
4165 struct snapshot_output *output;
4166
4167 LTTNG_ASSERT(session);
4168 LTTNG_ASSERT(outputs);
4169
4170 DBG("Cmd snapshot list outputs for session %s", session->name);
4171
4172 /*
4173 * Permission denied to create an output if the session is not
4174 * set in no output mode.
4175 */
4176 if (session->output_traces) {
4177 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4178 goto end;
4179 }
4180
4181 if (session->snapshot.nb_output == 0) {
4182 ret = 0;
4183 goto end;
4184 }
4185
4186 list = (lttng_snapshot_output *) zmalloc(session->snapshot.nb_output * sizeof(*list));
4187 if (!list) {
4188 ret = -LTTNG_ERR_NOMEM;
4189 goto end;
4190 }
4191
4192 /* Copy list from session to the new list object. */
4193 rcu_read_lock();
4194 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
4195 output, node.node) {
4196 LTTNG_ASSERT(output->consumer);
4197 list[idx].id = output->id;
4198 list[idx].max_size = output->max_size;
4199 if (lttng_strncpy(list[idx].name, output->name,
4200 sizeof(list[idx].name))) {
4201 ret = -LTTNG_ERR_INVALID;
4202 goto error;
4203 }
4204 if (output->consumer->type == CONSUMER_DST_LOCAL) {
4205 if (lttng_strncpy(list[idx].ctrl_url,
4206 output->consumer->dst.session_root_path,
4207 sizeof(list[idx].ctrl_url))) {
4208 ret = -LTTNG_ERR_INVALID;
4209 goto error;
4210 }
4211 } else {
4212 /* Control URI. */
4213 ret = uri_to_str_url(&output->consumer->dst.net.control,
4214 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
4215 if (ret < 0) {
4216 ret = -LTTNG_ERR_NOMEM;
4217 goto error;
4218 }
4219
4220 /* Data URI. */
4221 ret = uri_to_str_url(&output->consumer->dst.net.data,
4222 list[idx].data_url, sizeof(list[idx].data_url));
4223 if (ret < 0) {
4224 ret = -LTTNG_ERR_NOMEM;
4225 goto error;
4226 }
4227 }
4228 idx++;
4229 }
4230
4231 *outputs = list;
4232 list = NULL;
4233 ret = session->snapshot.nb_output;
4234 error:
4235 rcu_read_unlock();
4236 free(list);
4237 end:
4238 return ret;
4239 }
4240
4241 /*
4242 * Check if we can regenerate the metadata for this session.
4243 * Only kernel, UST per-uid and non-live sessions are supported.
4244 *
4245 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
4246 */
4247 static
4248 int check_regenerate_metadata_support(struct ltt_session *session)
4249 {
4250 int ret;
4251
4252 LTTNG_ASSERT(session);
4253
4254 if (session->live_timer != 0) {
4255 ret = LTTNG_ERR_LIVE_SESSION;
4256 goto end;
4257 }
4258 if (!session->active) {
4259 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4260 goto end;
4261 }
4262 if (session->ust_session) {
4263 switch (session->ust_session->buffer_type) {
4264 case LTTNG_BUFFER_PER_UID:
4265 break;
4266 case LTTNG_BUFFER_PER_PID:
4267 ret = LTTNG_ERR_PER_PID_SESSION;
4268 goto end;
4269 default:
4270 abort();
4271 ret = LTTNG_ERR_UNK;
4272 goto end;
4273 }
4274 }
4275 if (session->consumer->type == CONSUMER_DST_NET &&
4276 session->consumer->relay_minor_version < 8) {
4277 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
4278 goto end;
4279 }
4280 ret = 0;
4281
4282 end:
4283 return ret;
4284 }
4285
4286 static
4287 int clear_metadata_file(int fd)
4288 {
4289 int ret;
4290 off_t lseek_ret;
4291
4292 lseek_ret = lseek(fd, 0, SEEK_SET);
4293 if (lseek_ret < 0) {
4294 PERROR("lseek");
4295 ret = -1;
4296 goto end;
4297 }
4298
4299 ret = ftruncate(fd, 0);
4300 if (ret < 0) {
4301 PERROR("ftruncate");
4302 goto end;
4303 }
4304
4305 end:
4306 return ret;
4307 }
4308
4309 static
4310 int ust_regenerate_metadata(struct ltt_ust_session *usess)
4311 {
4312 int ret = 0;
4313 struct buffer_reg_uid *uid_reg = NULL;
4314 struct buffer_reg_session *session_reg = NULL;
4315
4316 rcu_read_lock();
4317 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
4318 struct ust_registry_session *registry;
4319 struct ust_registry_channel *chan;
4320 struct lttng_ht_iter iter_chan;
4321
4322 session_reg = uid_reg->registry;
4323 registry = session_reg->reg.ust;
4324
4325 pthread_mutex_lock(&registry->lock);
4326 registry->metadata_len_sent = 0;
4327 memset(registry->metadata, 0, registry->metadata_alloc_len);
4328 registry->metadata_len = 0;
4329 registry->metadata_version++;
4330 if (registry->metadata_fd > 0) {
4331 /* Clear the metadata file's content. */
4332 ret = clear_metadata_file(registry->metadata_fd);
4333 if (ret) {
4334 pthread_mutex_unlock(&registry->lock);
4335 goto end;
4336 }
4337 }
4338
4339 ret = ust_metadata_session_statedump(registry, NULL,
4340 registry->major, registry->minor);
4341 if (ret) {
4342 pthread_mutex_unlock(&registry->lock);
4343 ERR("Failed to generate session metadata (err = %d)",
4344 ret);
4345 goto end;
4346 }
4347 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
4348 chan, node.node) {
4349 struct ust_registry_event *event;
4350 struct lttng_ht_iter iter_event;
4351
4352 ret = ust_metadata_channel_statedump(registry, chan);
4353 if (ret) {
4354 pthread_mutex_unlock(&registry->lock);
4355 ERR("Failed to generate channel metadata "
4356 "(err = %d)", ret);
4357 goto end;
4358 }
4359 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
4360 event, node.node) {
4361 ret = ust_metadata_event_statedump(registry,
4362 chan, event);
4363 if (ret) {
4364 pthread_mutex_unlock(&registry->lock);
4365 ERR("Failed to generate event metadata "
4366 "(err = %d)", ret);
4367 goto end;
4368 }
4369 }
4370 }
4371 pthread_mutex_unlock(&registry->lock);
4372 }
4373
4374 end:
4375 rcu_read_unlock();
4376 return ret;
4377 }
4378
4379 /*
4380 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4381 *
4382 * Ask the consumer to truncate the existing metadata file(s) and
4383 * then regenerate the metadata. Live and per-pid sessions are not
4384 * supported and return an error.
4385 *
4386 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4387 */
4388 int cmd_regenerate_metadata(struct ltt_session *session)
4389 {
4390 int ret;
4391
4392 LTTNG_ASSERT(session);
4393
4394 ret = check_regenerate_metadata_support(session);
4395 if (ret) {
4396 goto end;
4397 }
4398
4399 if (session->kernel_session) {
4400 ret = kernctl_session_regenerate_metadata(
4401 session->kernel_session->fd);
4402 if (ret < 0) {
4403 ERR("Failed to regenerate the kernel metadata");
4404 goto end;
4405 }
4406 }
4407
4408 if (session->ust_session) {
4409 ret = ust_regenerate_metadata(session->ust_session);
4410 if (ret < 0) {
4411 ERR("Failed to regenerate the UST metadata");
4412 goto end;
4413 }
4414 }
4415 DBG("Cmd metadata regenerate for session %s", session->name);
4416 ret = LTTNG_OK;
4417
4418 end:
4419 return ret;
4420 }
4421
4422 /*
4423 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4424 *
4425 * Ask the tracer to regenerate a new statedump.
4426 *
4427 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4428 */
4429 int cmd_regenerate_statedump(struct ltt_session *session)
4430 {
4431 int ret;
4432
4433 LTTNG_ASSERT(session);
4434
4435 if (!session->active) {
4436 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4437 goto end;
4438 }
4439
4440 if (session->kernel_session) {
4441 ret = kernctl_session_regenerate_statedump(
4442 session->kernel_session->fd);
4443 /*
4444 * Currently, the statedump in kernel can only fail if out
4445 * of memory.
4446 */
4447 if (ret < 0) {
4448 if (ret == -ENOMEM) {
4449 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4450 } else {
4451 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4452 }
4453 ERR("Failed to regenerate the kernel statedump");
4454 goto end;
4455 }
4456 }
4457
4458 if (session->ust_session) {
4459 ret = ust_app_regenerate_statedump_all(session->ust_session);
4460 /*
4461 * Currently, the statedump in UST always returns 0.
4462 */
4463 if (ret < 0) {
4464 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4465 ERR("Failed to regenerate the UST statedump");
4466 goto end;
4467 }
4468 }
4469 DBG("Cmd regenerate statedump for session %s", session->name);
4470 ret = LTTNG_OK;
4471
4472 end:
4473 return ret;
4474 }
4475
4476 static
4477 enum lttng_error_code synchronize_tracer_notifier_register(
4478 struct notification_thread_handle *notification_thread,
4479 struct lttng_trigger *trigger, const struct lttng_credentials *cmd_creds)
4480 {
4481 enum lttng_error_code ret_code;
4482 const struct lttng_condition *condition =
4483 lttng_trigger_get_const_condition(trigger);
4484 const char *trigger_name;
4485 uid_t trigger_owner;
4486 enum lttng_trigger_status trigger_status;
4487 const enum lttng_domain_type trigger_domain =
4488 lttng_trigger_get_underlying_domain_type_restriction(
4489 trigger);
4490
4491 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner);
4492 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4493
4494 LTTNG_ASSERT(condition);
4495 LTTNG_ASSERT(lttng_condition_get_type(condition) ==
4496 LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES);
4497
4498 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4499 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4500 trigger_name : "(anonymous)";
4501
4502 session_lock_list();
4503 switch (trigger_domain) {
4504 case LTTNG_DOMAIN_KERNEL:
4505 {
4506 ret_code = kernel_register_event_notifier(trigger, cmd_creds);
4507 if (ret_code != LTTNG_OK) {
4508 enum lttng_error_code notif_thread_unregister_ret;
4509
4510 notif_thread_unregister_ret =
4511 notification_thread_command_unregister_trigger(
4512 notification_thread, trigger);
4513
4514 if (notif_thread_unregister_ret != LTTNG_OK) {
4515 /* Return the original error code. */
4516 ERR("Failed to unregister trigger from notification thread during error recovery: trigger name = '%s', trigger owner uid = %d, error code = %d",
4517 trigger_name,
4518 (int) trigger_owner,
4519 ret_code);
4520 }
4521 }
4522 break;
4523 }
4524 case LTTNG_DOMAIN_UST:
4525 ust_app_global_update_all_event_notifier_rules();
4526 break;
4527 case LTTNG_DOMAIN_JUL:
4528 case LTTNG_DOMAIN_LOG4J:
4529 case LTTNG_DOMAIN_PYTHON:
4530 {
4531 /* Agent domains. */
4532 struct agent *agt = agent_find_by_event_notifier_domain(
4533 trigger_domain);
4534
4535 if (!agt) {
4536 agt = agent_create(trigger_domain);
4537 if (!agt) {
4538 ret_code = LTTNG_ERR_NOMEM;
4539 goto end_unlock_session_list;
4540 }
4541
4542 agent_add(agt, the_trigger_agents_ht_by_domain);
4543 }
4544
4545 ret_code = (lttng_error_code) trigger_agent_enable(trigger, agt);
4546 if (ret_code != LTTNG_OK) {
4547 goto end_unlock_session_list;
4548 }
4549
4550 break;
4551 }
4552 case LTTNG_DOMAIN_NONE:
4553 default:
4554 abort();
4555 }
4556
4557 ret_code = LTTNG_OK;
4558 end_unlock_session_list:
4559 session_unlock_list();
4560 return ret_code;
4561 }
4562
4563 enum lttng_error_code cmd_register_trigger(const struct lttng_credentials *cmd_creds,
4564 struct lttng_trigger *trigger,
4565 bool is_trigger_anonymous,
4566 struct notification_thread_handle *notification_thread,
4567 struct lttng_trigger **return_trigger)
4568 {
4569 enum lttng_error_code ret_code;
4570 const char *trigger_name;
4571 uid_t trigger_owner;
4572 enum lttng_trigger_status trigger_status;
4573
4574 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4575 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4576 trigger_name : "(anonymous)";
4577
4578 trigger_status = lttng_trigger_get_owner_uid(
4579 trigger, &trigger_owner);
4580 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4581
4582 DBG("Running register trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4583 trigger_name, (int) trigger_owner,
4584 (int) lttng_credentials_get_uid(cmd_creds));
4585
4586 /*
4587 * Validate the trigger credentials against the command credentials.
4588 * Only the root user can register a trigger with non-matching
4589 * credentials.
4590 */
4591 if (!lttng_credentials_is_equal_uid(
4592 lttng_trigger_get_credentials(trigger),
4593 cmd_creds)) {
4594 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4595 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4596 trigger_name, (int) trigger_owner,
4597 (int) lttng_credentials_get_uid(cmd_creds));
4598 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4599 goto end;
4600 }
4601 }
4602
4603 /*
4604 * The bytecode generation also serves as a validation step for the
4605 * bytecode expressions.
4606 */
4607 ret_code = lttng_trigger_generate_bytecode(trigger, cmd_creds);
4608 if (ret_code != LTTNG_OK) {
4609 ERR("Failed to generate bytecode of trigger: trigger name = '%s', trigger owner uid = %d, error code = %d",
4610 trigger_name, (int) trigger_owner, ret_code);
4611 goto end;
4612 }
4613
4614 /*
4615 * A reference to the trigger is acquired by the notification thread.
4616 * It is safe to return the same trigger to the caller since it the
4617 * other user holds a reference.
4618 *
4619 * The trigger is modified during the execution of the
4620 * "register trigger" command. However, by the time the command returns,
4621 * it is safe to use without any locking as its properties are
4622 * immutable.
4623 */
4624 ret_code = notification_thread_command_register_trigger(
4625 notification_thread, trigger, is_trigger_anonymous);
4626 if (ret_code != LTTNG_OK) {
4627 DBG("Failed to register trigger to notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4628 trigger_name, (int) trigger_owner, ret_code);
4629 goto end;
4630 }
4631
4632 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4633 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4634 trigger_name : "(anonymous)";
4635
4636 /*
4637 * Synchronize tracers if the trigger adds an event notifier.
4638 */
4639 if (lttng_trigger_needs_tracer_notifier(trigger)) {
4640 ret_code = synchronize_tracer_notifier_register(notification_thread,
4641 trigger, cmd_creds);
4642 if (ret_code != LTTNG_OK) {
4643 ERR("Error registering tracer notifier: %s",
4644 lttng_strerror(-ret_code));
4645 goto end;
4646 }
4647 }
4648
4649 /*
4650 * Return an updated trigger to the client.
4651 *
4652 * Since a modified version of the same trigger is returned, acquire a
4653 * reference to the trigger so the caller doesn't have to care if those
4654 * are distinct instances or not.
4655 */
4656 if (ret_code == LTTNG_OK) {
4657 lttng_trigger_get(trigger);
4658 *return_trigger = trigger;
4659 /* Ownership of trigger was transferred to caller. */
4660 trigger = NULL;
4661 }
4662 end:
4663 return ret_code;
4664 }
4665
4666 static
4667 enum lttng_error_code synchronize_tracer_notifier_unregister(
4668 const struct lttng_trigger *trigger)
4669 {
4670 enum lttng_error_code ret_code;
4671 const struct lttng_condition *condition =
4672 lttng_trigger_get_const_condition(trigger);
4673 const enum lttng_domain_type trigger_domain =
4674 lttng_trigger_get_underlying_domain_type_restriction(
4675 trigger);
4676
4677 LTTNG_ASSERT(condition);
4678 LTTNG_ASSERT(lttng_condition_get_type(condition) ==
4679 LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES);
4680
4681 session_lock_list();
4682 switch (trigger_domain) {
4683 case LTTNG_DOMAIN_KERNEL:
4684 ret_code = kernel_unregister_event_notifier(trigger);
4685 if (ret_code != LTTNG_OK) {
4686 goto end_unlock_session_list;
4687 }
4688
4689 break;
4690 case LTTNG_DOMAIN_UST:
4691 ust_app_global_update_all_event_notifier_rules();
4692 break;
4693 case LTTNG_DOMAIN_JUL:
4694 case LTTNG_DOMAIN_LOG4J:
4695 case LTTNG_DOMAIN_PYTHON:
4696 {
4697 /* Agent domains. */
4698 struct agent *agt = agent_find_by_event_notifier_domain(
4699 trigger_domain);
4700
4701 /*
4702 * This trigger was never registered in the first place. Calling
4703 * this function under those circumstances is an internal error.
4704 */
4705 LTTNG_ASSERT(agt);
4706 ret_code = (lttng_error_code) trigger_agent_disable(trigger, agt);
4707 if (ret_code != LTTNG_OK) {
4708 goto end_unlock_session_list;
4709 }
4710
4711 break;
4712 }
4713 case LTTNG_DOMAIN_NONE:
4714 default:
4715 abort();
4716 }
4717
4718 ret_code = LTTNG_OK;
4719
4720 end_unlock_session_list:
4721 session_unlock_list();
4722 return ret_code;
4723 }
4724
4725 enum lttng_error_code cmd_unregister_trigger(const struct lttng_credentials *cmd_creds,
4726 const struct lttng_trigger *trigger,
4727 struct notification_thread_handle *notification_thread)
4728 {
4729 enum lttng_error_code ret_code;
4730 const char *trigger_name;
4731 uid_t trigger_owner;
4732 enum lttng_trigger_status trigger_status;
4733 struct lttng_trigger *sessiond_trigger = NULL;
4734
4735 trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
4736 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ? trigger_name : "(anonymous)";
4737 trigger_status = lttng_trigger_get_owner_uid(trigger, &trigger_owner);
4738 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4739
4740 DBG("Running unregister trigger command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4741 trigger_name, (int) trigger_owner,
4742 (int) lttng_credentials_get_uid(cmd_creds));
4743
4744 /*
4745 * Validate the trigger credentials against the command credentials.
4746 * Only the root user can unregister a trigger with non-matching
4747 * credentials.
4748 */
4749 if (!lttng_credentials_is_equal_uid(
4750 lttng_trigger_get_credentials(trigger),
4751 cmd_creds)) {
4752 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4753 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4754 trigger_name, (int) trigger_owner,
4755 (int) lttng_credentials_get_uid(cmd_creds));
4756 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4757 goto end;
4758 }
4759 }
4760
4761 /* Fetch the sessiond side trigger object. */
4762 ret_code = notification_thread_command_get_trigger(
4763 notification_thread, trigger, &sessiond_trigger);
4764 if (ret_code != LTTNG_OK) {
4765 DBG("Failed to get trigger from notification thread during unregister: trigger name = '%s', trigger owner uid = %d, error code = %d",
4766 trigger_name, (int) trigger_owner, ret_code);
4767 goto end;
4768 }
4769
4770 LTTNG_ASSERT(sessiond_trigger);
4771
4772 /*
4773 * From this point on, no matter what, consider the trigger
4774 * unregistered.
4775 *
4776 * We set the unregistered state of the sessiond side trigger object in
4777 * the client thread since we want to minimize the possibility of the
4778 * notification thread being stalled due to a long execution of an
4779 * action that required the trigger lock.
4780 */
4781 lttng_trigger_set_as_unregistered(sessiond_trigger);
4782
4783 ret_code = notification_thread_command_unregister_trigger(notification_thread,
4784 trigger);
4785 if (ret_code != LTTNG_OK) {
4786 DBG("Failed to unregister trigger from notification thread: trigger name = '%s', trigger owner uid = %d, error code = %d",
4787 trigger_name, (int) trigger_owner, ret_code);
4788 goto end;
4789 }
4790
4791 /*
4792 * Synchronize tracers if the trigger removes an event notifier.
4793 * Do this even if the trigger unregistration failed to at least stop
4794 * the tracers from producing notifications associated with this
4795 * event notifier.
4796 */
4797 if (lttng_trigger_needs_tracer_notifier(trigger)) {
4798 ret_code = synchronize_tracer_notifier_unregister(trigger);
4799 if (ret_code != LTTNG_OK) {
4800 ERR("Error unregistering trigger to tracer.");
4801 goto end;
4802 }
4803
4804 }
4805
4806 end:
4807 lttng_trigger_put(sessiond_trigger);
4808 return ret_code;
4809 }
4810
4811 enum lttng_error_code cmd_list_triggers(struct command_ctx *cmd_ctx,
4812 struct notification_thread_handle *notification_thread,
4813 struct lttng_triggers **return_triggers)
4814 {
4815 int ret;
4816 enum lttng_error_code ret_code;
4817 struct lttng_triggers *triggers = NULL;
4818
4819 /* Get the set of triggers from the notification thread. */
4820 ret_code = notification_thread_command_list_triggers(
4821 notification_thread, cmd_ctx->creds.uid, &triggers);
4822 if (ret_code != LTTNG_OK) {
4823 goto end;
4824 }
4825
4826 ret = lttng_triggers_remove_hidden_triggers(triggers);
4827 if (ret) {
4828 ret_code = LTTNG_ERR_UNK;
4829 goto end;
4830 }
4831
4832 *return_triggers = triggers;
4833 triggers = NULL;
4834 ret_code = LTTNG_OK;
4835 end:
4836 lttng_triggers_destroy(triggers);
4837 return ret_code;
4838 }
4839
4840 enum lttng_error_code cmd_execute_error_query(const struct lttng_credentials *cmd_creds,
4841 const struct lttng_error_query *query,
4842 struct lttng_error_query_results **_results,
4843 struct notification_thread_handle *notification_thread)
4844 {
4845 enum lttng_error_code ret_code;
4846 const struct lttng_trigger *query_target_trigger;
4847 const struct lttng_action *query_target_action = NULL;
4848 struct lttng_trigger *matching_trigger = NULL;
4849 const char *trigger_name;
4850 uid_t trigger_owner;
4851 enum lttng_trigger_status trigger_status;
4852 struct lttng_error_query_results *results = NULL;
4853
4854 switch (lttng_error_query_get_target_type(query)) {
4855 case LTTNG_ERROR_QUERY_TARGET_TYPE_TRIGGER:
4856 query_target_trigger = lttng_error_query_trigger_borrow_target(query);
4857 break;
4858 case LTTNG_ERROR_QUERY_TARGET_TYPE_CONDITION:
4859 query_target_trigger =
4860 lttng_error_query_condition_borrow_target(query);
4861 break;
4862 case LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION:
4863 query_target_trigger = lttng_error_query_action_borrow_trigger_target(
4864 query);
4865 break;
4866 default:
4867 abort();
4868 }
4869
4870 LTTNG_ASSERT(query_target_trigger);
4871
4872 ret_code = notification_thread_command_get_trigger(notification_thread,
4873 query_target_trigger, &matching_trigger);
4874 if (ret_code != LTTNG_OK) {
4875 goto end;
4876 }
4877
4878 /* No longer needed. */
4879 query_target_trigger = NULL;
4880
4881 if (lttng_error_query_get_target_type(query) ==
4882 LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION) {
4883 /* Get the sessiond-side version of the target action. */
4884 query_target_action =
4885 lttng_error_query_action_borrow_action_target(
4886 query, matching_trigger);
4887 }
4888
4889 trigger_status = lttng_trigger_get_name(matching_trigger, &trigger_name);
4890 trigger_name = trigger_status == LTTNG_TRIGGER_STATUS_OK ?
4891 trigger_name : "(anonymous)";
4892 trigger_status = lttng_trigger_get_owner_uid(matching_trigger,
4893 &trigger_owner);
4894 LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
4895
4896 results = lttng_error_query_results_create();
4897 if (!results) {
4898 ret_code = LTTNG_ERR_NOMEM;
4899 goto end;
4900 }
4901
4902 DBG("Running \"execute error query\" command: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4903 trigger_name, (int) trigger_owner,
4904 (int) lttng_credentials_get_uid(cmd_creds));
4905
4906 /*
4907 * Validate the trigger credentials against the command credentials.
4908 * Only the root user can target a trigger with non-matching
4909 * credentials.
4910 */
4911 if (!lttng_credentials_is_equal_uid(
4912 lttng_trigger_get_credentials(matching_trigger),
4913 cmd_creds)) {
4914 if (lttng_credentials_get_uid(cmd_creds) != 0) {
4915 ERR("Trigger credentials do not match the command credentials: trigger name = '%s', trigger owner uid = %d, command creds uid = %d",
4916 trigger_name, (int) trigger_owner,
4917 (int) lttng_credentials_get_uid(cmd_creds));
4918 ret_code = LTTNG_ERR_INVALID_TRIGGER;
4919 goto end;
4920 }
4921 }
4922
4923 switch (lttng_error_query_get_target_type(query)) {
4924 case LTTNG_ERROR_QUERY_TARGET_TYPE_TRIGGER:
4925 trigger_status = lttng_trigger_add_error_results(
4926 matching_trigger, results);
4927
4928 switch (trigger_status) {
4929 case LTTNG_TRIGGER_STATUS_OK:
4930 break;
4931 default:
4932 ret_code = LTTNG_ERR_UNK;
4933 goto end;
4934 }
4935
4936 break;
4937 case LTTNG_ERROR_QUERY_TARGET_TYPE_CONDITION:
4938 {
4939 trigger_status = lttng_trigger_condition_add_error_results(
4940 matching_trigger, results);
4941
4942 switch (trigger_status) {
4943 case LTTNG_TRIGGER_STATUS_OK:
4944 break;
4945 default:
4946 ret_code = LTTNG_ERR_UNK;
4947 goto end;
4948 }
4949
4950 break;
4951 }
4952 case LTTNG_ERROR_QUERY_TARGET_TYPE_ACTION:
4953 {
4954 const enum lttng_action_status action_status =
4955 lttng_action_add_error_query_results(
4956 query_target_action, results);
4957
4958 switch (action_status) {
4959 case LTTNG_ACTION_STATUS_OK:
4960 break;
4961 default:
4962 ret_code = LTTNG_ERR_UNK;
4963 goto end;
4964 }
4965
4966 break;
4967 }
4968 default:
4969 abort();
4970 break;
4971 }
4972
4973 *_results = results;
4974 results = NULL;
4975 ret_code = LTTNG_OK;
4976 end:
4977 lttng_trigger_put(matching_trigger);
4978 lttng_error_query_results_destroy(results);
4979 return ret_code;
4980 }
4981
4982 /*
4983 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4984 * snapshot output is *not* set with a remote destination.
4985 *
4986 * Return LTTNG_OK on success or a LTTNG_ERR code.
4987 */
4988 static enum lttng_error_code set_relayd_for_snapshot(
4989 struct consumer_output *output,
4990 const struct ltt_session *session)
4991 {
4992 enum lttng_error_code status = LTTNG_OK;
4993 struct lttng_ht_iter iter;
4994 struct consumer_socket *socket;
4995 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4996 const char *base_path;
4997
4998 LTTNG_ASSERT(output);
4999 LTTNG_ASSERT(session);
5000
5001 DBG2("Set relayd object from snapshot output");
5002
5003 if (session->current_trace_chunk) {
5004 enum lttng_trace_chunk_status chunk_status =
5005 lttng_trace_chunk_get_id(
5006 session->current_trace_chunk,
5007 &current_chunk_id.value);
5008
5009 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
5010 current_chunk_id.is_set = true;
5011 } else {
5012 ERR("Failed to get current trace chunk id");
5013 status = LTTNG_ERR_UNK;
5014 goto error;
5015 }
5016 }
5017
5018 /* Ignore if snapshot consumer output is not network. */
5019 if (output->type != CONSUMER_DST_NET) {
5020 goto error;
5021 }
5022
5023 /*
5024 * The snapshot record URI base path overrides the session
5025 * base path.
5026 */
5027 if (output->dst.net.control.subdir[0] != '\0') {
5028 base_path = output->dst.net.control.subdir;
5029 } else {
5030 base_path = session->base_path;
5031 }
5032
5033 /*
5034 * For each consumer socket, create and send the relayd object of the
5035 * snapshot output.
5036 */
5037 rcu_read_lock();
5038 cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
5039 socket, node.node) {
5040 pthread_mutex_lock(socket->lock);
5041 status = send_consumer_relayd_sockets(LTTNG_DOMAIN_NONE, session->id,
5042 output, socket,
5043 session->name, session->hostname,
5044 base_path,
5045 session->live_timer,
5046 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
5047 session->creation_time,
5048 session->name_contains_creation_time);
5049 pthread_mutex_unlock(socket->lock);
5050 if (status != LTTNG_OK) {
5051 rcu_read_unlock();
5052 goto error;
5053 }
5054 }
5055 rcu_read_unlock();
5056
5057 error:
5058 return status;
5059 }
5060
5061 /*
5062 * Record a kernel snapshot.
5063 *
5064 * Return LTTNG_OK on success or a LTTNG_ERR code.
5065 */
5066 static enum lttng_error_code record_kernel_snapshot(
5067 struct ltt_kernel_session *ksess,
5068 const struct consumer_output *output,
5069 const struct ltt_session *session,
5070 int wait, uint64_t nb_packets_per_stream)
5071 {
5072 enum lttng_error_code status;
5073
5074 LTTNG_ASSERT(ksess);
5075 LTTNG_ASSERT(output);
5076 LTTNG_ASSERT(session);
5077
5078 status = kernel_snapshot_record(
5079 ksess, output, wait, nb_packets_per_stream);
5080 return status;
5081 }
5082
5083 /*
5084 * Record a UST snapshot.
5085 *
5086 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
5087 */
5088 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
5089 const struct consumer_output *output,
5090 const struct ltt_session *session,
5091 int wait, uint64_t nb_packets_per_stream)
5092 {
5093 enum lttng_error_code status;
5094
5095 LTTNG_ASSERT(usess);
5096 LTTNG_ASSERT(output);
5097 LTTNG_ASSERT(session);
5098
5099 status = ust_app_snapshot_record(
5100 usess, output, wait, nb_packets_per_stream);
5101 return status;
5102 }
5103
5104 static
5105 uint64_t get_session_size_one_more_packet_per_stream(
5106 const struct ltt_session *session, uint64_t cur_nr_packets)
5107 {
5108 uint64_t tot_size = 0;
5109
5110 if (session->kernel_session) {
5111 struct ltt_kernel_channel *chan;
5112 const struct ltt_kernel_session *ksess =
5113 session->kernel_session;
5114
5115 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
5116 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
5117 /*
5118 * Don't take channel into account if we
5119 * already grab all its packets.
5120 */
5121 continue;
5122 }
5123 tot_size += chan->channel->attr.subbuf_size
5124 * chan->stream_count;
5125 }
5126 }
5127
5128 if (session->ust_session) {
5129 const struct ltt_ust_session *usess = session->ust_session;
5130
5131 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
5132 cur_nr_packets);
5133 }
5134
5135 return tot_size;
5136 }
5137
5138 /*
5139 * Calculate the number of packets we can grab from each stream that
5140 * fits within the overall snapshot max size.
5141 *
5142 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
5143 * the number of packets per stream.
5144 *
5145 * TODO: this approach is not perfect: we consider the worse case
5146 * (packet filling the sub-buffers) as an upper bound, but we could do
5147 * better if we do this calculation while we actually grab the packet
5148 * content: we would know how much padding we don't actually store into
5149 * the file.
5150 *
5151 * This algorithm is currently bounded by the number of packets per
5152 * stream.
5153 *
5154 * Since we call this algorithm before actually grabbing the data, it's
5155 * an approximation: for instance, applications could appear/disappear
5156 * in between this call and actually grabbing data.
5157 */
5158 static
5159 int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
5160 uint64_t max_size)
5161 {
5162 int64_t size_left;
5163 uint64_t cur_nb_packets = 0;
5164
5165 if (!max_size) {
5166 return 0; /* Infinite */
5167 }
5168
5169 size_left = max_size;
5170 for (;;) {
5171 uint64_t one_more_packet_tot_size;
5172
5173 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(
5174 session, cur_nb_packets);
5175 if (!one_more_packet_tot_size) {
5176 /* We are already grabbing all packets. */
5177 break;
5178 }
5179 size_left -= one_more_packet_tot_size;
5180 if (size_left < 0) {
5181 break;
5182 }
5183 cur_nb_packets++;
5184 }
5185 if (!cur_nb_packets && size_left != max_size) {
5186 /* Not enough room to grab one packet of each stream, error. */
5187 return -1;
5188 }
5189 return cur_nb_packets;
5190 }
5191
5192 static
5193 enum lttng_error_code snapshot_record(struct ltt_session *session,
5194 const struct snapshot_output *snapshot_output, int wait)
5195 {
5196 int64_t nb_packets_per_stream;
5197 char snapshot_chunk_name[LTTNG_NAME_MAX];
5198 int ret;
5199 enum lttng_error_code ret_code = LTTNG_OK;
5200 struct lttng_trace_chunk *snapshot_trace_chunk;
5201 struct consumer_output *original_ust_consumer_output = NULL;
5202 struct consumer_output *original_kernel_consumer_output = NULL;
5203 struct consumer_output *snapshot_ust_consumer_output = NULL;
5204 struct consumer_output *snapshot_kernel_consumer_output = NULL;
5205
5206 ret = snprintf(snapshot_chunk_name, sizeof(snapshot_chunk_name),
5207 "%s-%s-%" PRIu64,
5208 snapshot_output->name,
5209 snapshot_output->datetime,
5210 snapshot_output->nb_snapshot);
5211 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
5212 ERR("Failed to format snapshot name");
5213 ret_code = LTTNG_ERR_INVALID;
5214 goto error;
5215 }
5216 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
5217 snapshot_output->name, session->name,
5218 snapshot_chunk_name);
5219 if (!session->kernel_session && !session->ust_session) {
5220 ERR("Failed to record snapshot as no channels exist");
5221 ret_code = LTTNG_ERR_NO_CHANNEL;
5222 goto error;
5223 }
5224
5225 if (session->kernel_session) {
5226 original_kernel_consumer_output =
5227 session->kernel_session->consumer;
5228 snapshot_kernel_consumer_output =
5229 consumer_copy_output(snapshot_output->consumer);
5230 strcpy(snapshot_kernel_consumer_output->chunk_path,
5231 snapshot_chunk_name);
5232
5233 /* Copy the original domain subdir. */
5234 strcpy(snapshot_kernel_consumer_output->domain_subdir,
5235 original_kernel_consumer_output->domain_subdir);
5236
5237 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
5238 original_kernel_consumer_output);
5239 if (ret < 0) {
5240 ERR("Failed to copy consumer sockets from snapshot output configuration");
5241 ret_code = LTTNG_ERR_NOMEM;
5242 goto error;
5243 }
5244 ret_code = set_relayd_for_snapshot(
5245 snapshot_kernel_consumer_output, session);
5246 if (ret_code != LTTNG_OK) {
5247 ERR("Failed to setup relay daemon for kernel tracer snapshot");
5248 goto error;
5249 }
5250 session->kernel_session->consumer =
5251 snapshot_kernel_consumer_output;
5252 }
5253 if (session->ust_session) {
5254 original_ust_consumer_output = session->ust_session->consumer;
5255 snapshot_ust_consumer_output =
5256 consumer_copy_output(snapshot_output->consumer);
5257 strcpy(snapshot_ust_consumer_output->chunk_path,
5258 snapshot_chunk_name);
5259
5260 /* Copy the original domain subdir. */
5261 strcpy(snapshot_ust_consumer_output->domain_subdir,
5262 original_ust_consumer_output->domain_subdir);
5263
5264 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
5265 original_ust_consumer_output);
5266 if (ret < 0) {
5267 ERR("Failed to copy consumer sockets from snapshot output configuration");
5268 ret_code = LTTNG_ERR_NOMEM;
5269 goto error;
5270 }
5271 ret_code = set_relayd_for_snapshot(
5272 snapshot_ust_consumer_output, session);
5273 if (ret_code != LTTNG_OK) {
5274 ERR("Failed to setup relay daemon for userspace tracer snapshot");
5275 goto error;
5276 }
5277 session->ust_session->consumer =
5278 snapshot_ust_consumer_output;
5279 }
5280
5281 snapshot_trace_chunk = session_create_new_trace_chunk(session,
5282 snapshot_kernel_consumer_output ?:
5283 snapshot_ust_consumer_output,
5284 consumer_output_get_base_path(
5285 snapshot_output->consumer),
5286 snapshot_chunk_name);
5287 if (!snapshot_trace_chunk) {
5288 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
5289 session->name);
5290 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
5291 goto error;
5292 }
5293 LTTNG_ASSERT(!session->current_trace_chunk);
5294 ret = session_set_trace_chunk(session, snapshot_trace_chunk, NULL);
5295 lttng_trace_chunk_put(snapshot_trace_chunk);
5296 snapshot_trace_chunk = NULL;
5297 if (ret) {
5298 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
5299 session->name);
5300 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5301 goto error;
5302 }
5303
5304 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
5305 snapshot_output->max_size);
5306 if (nb_packets_per_stream < 0) {
5307 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
5308 goto error_close_trace_chunk;
5309 }
5310
5311 if (session->kernel_session) {
5312 ret_code = record_kernel_snapshot(session->kernel_session,
5313 snapshot_kernel_consumer_output, session,
5314 wait, nb_packets_per_stream);
5315 if (ret_code != LTTNG_OK) {
5316 goto error_close_trace_chunk;
5317 }
5318 }
5319
5320 if (session->ust_session) {
5321 ret_code = record_ust_snapshot(session->ust_session,
5322 snapshot_ust_consumer_output, session,
5323 wait, nb_packets_per_stream);
5324 if (ret_code != LTTNG_OK) {
5325 goto error_close_trace_chunk;
5326 }
5327 }
5328
5329 error_close_trace_chunk:
5330 if (session_set_trace_chunk(session, NULL, &snapshot_trace_chunk)) {
5331 ERR("Failed to release the current trace chunk of session \"%s\"",
5332 session->name);
5333 ret_code = LTTNG_ERR_UNK;
5334 }
5335
5336 if (session_close_trace_chunk(session, snapshot_trace_chunk,
5337 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION, NULL)) {
5338 /*
5339 * Don't goto end; make sure the chunk is closed for the session
5340 * to allow future snapshots.
5341 */
5342 ERR("Failed to close snapshot trace chunk of session \"%s\"",
5343 session->name);
5344 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5345 }
5346
5347 lttng_trace_chunk_put(snapshot_trace_chunk);
5348 snapshot_trace_chunk = NULL;
5349 error:
5350 if (original_ust_consumer_output) {
5351 session->ust_session->consumer = original_ust_consumer_output;
5352 }
5353 if (original_kernel_consumer_output) {
5354 session->kernel_session->consumer =
5355 original_kernel_consumer_output;
5356 }
5357 consumer_output_put(snapshot_ust_consumer_output);
5358 consumer_output_put(snapshot_kernel_consumer_output);
5359 return ret_code;
5360 }
5361
5362 /*
5363 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
5364 *
5365 * The wait parameter is ignored so this call always wait for the snapshot to
5366 * complete before returning.
5367 *
5368 * Return LTTNG_OK on success or else a LTTNG_ERR code.
5369 */
5370 int cmd_snapshot_record(struct ltt_session *session,
5371 const struct lttng_snapshot_output *output, int wait)
5372 {
5373 enum lttng_error_code cmd_ret = LTTNG_OK;
5374 int ret;
5375 unsigned int snapshot_success = 0;
5376 char datetime[16];
5377 struct snapshot_output *tmp_output = NULL;
5378
5379 LTTNG_ASSERT(session);
5380 LTTNG_ASSERT(output);
5381
5382 DBG("Cmd snapshot record for session %s", session->name);
5383
5384 /* Get the datetime for the snapshot output directory. */
5385 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
5386 sizeof(datetime));
5387 if (!ret) {
5388 cmd_ret = LTTNG_ERR_INVALID;
5389 goto error;
5390 }
5391
5392 /*
5393 * Permission denied to create an output if the session is not
5394 * set in no output mode.
5395 */
5396 if (session->output_traces) {
5397 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
5398 goto error;
5399 }
5400
5401 /* The session needs to be started at least once. */
5402 if (!session->has_been_started) {
5403 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5404 goto error;
5405 }
5406
5407 /* Use temporary output for the session. */
5408 if (*output->ctrl_url != '\0') {
5409 tmp_output = snapshot_output_alloc();
5410 if (!tmp_output) {
5411 cmd_ret = LTTNG_ERR_NOMEM;
5412 goto error;
5413 }
5414
5415 ret = snapshot_output_init(session, output->max_size,
5416 output->name,
5417 output->ctrl_url, output->data_url,
5418 session->consumer,
5419 tmp_output, NULL);
5420 if (ret < 0) {
5421 if (ret == -ENOMEM) {
5422 cmd_ret = LTTNG_ERR_NOMEM;
5423 } else {
5424 cmd_ret = LTTNG_ERR_INVALID;
5425 }
5426 goto error;
5427 }
5428 /* Use the global session count for the temporary snapshot. */
5429 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
5430
5431 /* Use the global datetime */
5432 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
5433 cmd_ret = snapshot_record(session, tmp_output, wait);
5434 if (cmd_ret != LTTNG_OK) {
5435 goto error;
5436 }
5437 snapshot_success = 1;
5438 } else {
5439 struct snapshot_output *sout;
5440 struct lttng_ht_iter iter;
5441
5442 rcu_read_lock();
5443 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
5444 &iter.iter, sout, node.node) {
5445 struct snapshot_output output_copy;
5446
5447 /*
5448 * Make a local copy of the output and override output
5449 * parameters with those provided as part of the
5450 * command.
5451 */
5452 memcpy(&output_copy, sout, sizeof(output_copy));
5453
5454 if (output->max_size != (uint64_t) -1ULL) {
5455 output_copy.max_size = output->max_size;
5456 }
5457
5458 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
5459 memcpy(output_copy.datetime, datetime,
5460 sizeof(datetime));
5461
5462 /* Use temporary name. */
5463 if (*output->name != '\0') {
5464 if (lttng_strncpy(output_copy.name,
5465 output->name,
5466 sizeof(output_copy.name))) {
5467 cmd_ret = LTTNG_ERR_INVALID;
5468 rcu_read_unlock();
5469 goto error;
5470 }
5471 }
5472
5473 cmd_ret = snapshot_record(session, &output_copy, wait);
5474 if (cmd_ret != LTTNG_OK) {
5475 rcu_read_unlock();
5476 goto error;
5477 }
5478 snapshot_success = 1;
5479 }
5480 rcu_read_unlock();
5481 }
5482
5483 if (snapshot_success) {
5484 session->snapshot.nb_snapshot++;
5485 } else {
5486 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
5487 }
5488
5489 error:
5490 if (tmp_output) {
5491 snapshot_output_destroy(tmp_output);
5492 }
5493 return cmd_ret;
5494 }
5495
5496 /*
5497 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
5498 */
5499 int cmd_set_session_shm_path(struct ltt_session *session,
5500 const char *shm_path)
5501 {
5502 /* Safety net */
5503 LTTNG_ASSERT(session);
5504
5505 /*
5506 * Can only set shm path before session is started.
5507 */
5508 if (session->has_been_started) {
5509 return LTTNG_ERR_SESSION_STARTED;
5510 }
5511
5512 strncpy(session->shm_path, shm_path,
5513 sizeof(session->shm_path));
5514 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
5515
5516 return LTTNG_OK;
5517 }
5518
5519 /*
5520 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
5521 *
5522 * Ask the consumer to rotate the session output directory.
5523 * The session lock must be held.
5524 *
5525 * Returns LTTNG_OK on success or else a negative LTTng error code.
5526 */
5527 int cmd_rotate_session(struct ltt_session *session,
5528 struct lttng_rotate_session_return *rotate_return,
5529 bool quiet_rotation,
5530 enum lttng_trace_chunk_command_type command)
5531 {
5532 int ret;
5533 uint64_t ongoing_rotation_chunk_id;
5534 enum lttng_error_code cmd_ret = LTTNG_OK;
5535 struct lttng_trace_chunk *chunk_being_archived = NULL;
5536 struct lttng_trace_chunk *new_trace_chunk = NULL;
5537 enum lttng_trace_chunk_status chunk_status;
5538 bool failed_to_rotate = false;
5539 enum lttng_error_code rotation_fail_code = LTTNG_OK;
5540
5541 LTTNG_ASSERT(session);
5542
5543 if (!session->has_been_started) {
5544 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5545 goto end;
5546 }
5547
5548 /*
5549 * Explicit rotation is not supported for live sessions.
5550 * However, live sessions can perform a quiet rotation on
5551 * destroy.
5552 * Rotation is not supported for snapshot traces (no output).
5553 */
5554 if ((!quiet_rotation && session->live_timer) ||
5555 !session->output_traces) {
5556 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5557 goto end;
5558 }
5559
5560 /* Unsupported feature in lttng-relayd before 2.11. */
5561 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
5562 (session->consumer->relay_major_version == 2 &&
5563 session->consumer->relay_minor_version < 11)) {
5564 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
5565 goto end;
5566 }
5567
5568 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
5569 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
5570 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
5571 goto end;
5572 }
5573
5574 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
5575 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
5576 session->name);
5577 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
5578 goto end;
5579 }
5580
5581 /*
5582 * After a stop, we only allow one rotation to occur, the other ones are
5583 * useless until a new start.
5584 */
5585 if (session->rotated_after_last_stop) {
5586 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
5587 session->name);
5588 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
5589 goto end;
5590 }
5591
5592 /*
5593 * After a stop followed by a clear, disallow following rotations a they would
5594 * generate empty chunks.
5595 */
5596 if (session->cleared_after_last_stop) {
5597 DBG("Session \"%s\" was already cleared after stop, refusing rotation",
5598 session->name);
5599 cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
5600 goto end;
5601 }
5602
5603 if (session->active) {
5604 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
5605 NULL, NULL);
5606 if (!new_trace_chunk) {
5607 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
5608 goto error;
5609 }
5610 }
5611
5612 /*
5613 * The current trace chunk becomes the chunk being archived.
5614 *
5615 * After this point, "chunk_being_archived" must absolutely
5616 * be closed on the consumer(s), otherwise it will never be
5617 * cleaned-up, which will result in a leak.
5618 */
5619 ret = session_set_trace_chunk(session, new_trace_chunk,
5620 &chunk_being_archived);
5621 if (ret) {
5622 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5623 goto error;
5624 }
5625
5626 if (session->kernel_session) {
5627 cmd_ret = kernel_rotate_session(session);
5628 if (cmd_ret != LTTNG_OK) {
5629 failed_to_rotate = true;
5630 rotation_fail_code = cmd_ret;
5631 }
5632 }
5633 if (session->ust_session) {
5634 cmd_ret = ust_app_rotate_session(session);
5635 if (cmd_ret != LTTNG_OK) {
5636 failed_to_rotate = true;
5637 rotation_fail_code = cmd_ret;
5638 }
5639 }
5640
5641 if (!session->active) {
5642 session->rotated_after_last_stop = true;
5643 }
5644
5645 if (!chunk_being_archived) {
5646 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
5647 session->name);
5648 if (failed_to_rotate) {
5649 cmd_ret = rotation_fail_code;
5650 goto error;
5651 }
5652 cmd_ret = LTTNG_OK;
5653 goto end;
5654 }
5655
5656 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5657 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
5658 &ongoing_rotation_chunk_id);
5659 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5660
5661 ret = session_close_trace_chunk(session, chunk_being_archived,
5662 command, session->last_chunk_path);
5663 if (ret) {
5664 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5665 goto error;
5666 }
5667
5668 if (failed_to_rotate) {
5669 cmd_ret = rotation_fail_code;
5670 goto error;
5671 }
5672
5673 session->quiet_rotation = quiet_rotation;
5674 ret = timer_session_rotation_pending_check_start(session,
5675 DEFAULT_ROTATE_PENDING_TIMER);
5676 if (ret) {
5677 cmd_ret = LTTNG_ERR_UNK;
5678 goto error;
5679 }
5680
5681 if (rotate_return) {
5682 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5683 }
5684
5685 session->chunk_being_archived = chunk_being_archived;
5686 chunk_being_archived = NULL;
5687 if (!quiet_rotation) {
5688 ret = notification_thread_command_session_rotation_ongoing(
5689 the_notification_thread_handle, session->name,
5690 session->uid, session->gid,
5691 ongoing_rotation_chunk_id);
5692 if (ret != LTTNG_OK) {
5693 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5694 session->name);
5695 cmd_ret = (lttng_error_code) ret;
5696 }
5697 }
5698
5699 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5700 session->name, ongoing_rotation_chunk_id);
5701 end:
5702 lttng_trace_chunk_put(new_trace_chunk);
5703 lttng_trace_chunk_put(chunk_being_archived);
5704 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5705 return ret;
5706 error:
5707 if (session_reset_rotation_state(session,
5708 LTTNG_ROTATION_STATE_ERROR)) {
5709 ERR("Failed to reset rotation state of session \"%s\"",
5710 session->name);
5711 }
5712 goto end;
5713 }
5714
5715 /*
5716 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5717 *
5718 * Check if the session has finished its rotation.
5719 *
5720 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5721 */
5722 int cmd_rotate_get_info(struct ltt_session *session,
5723 struct lttng_rotation_get_info_return *info_return,
5724 uint64_t rotation_id)
5725 {
5726 enum lttng_error_code cmd_ret = LTTNG_OK;
5727 enum lttng_rotation_state rotation_state;
5728
5729 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
5730 session->most_recent_chunk_id.value);
5731
5732 if (session->chunk_being_archived) {
5733 enum lttng_trace_chunk_status chunk_status;
5734 uint64_t chunk_id;
5735
5736 chunk_status = lttng_trace_chunk_get_id(
5737 session->chunk_being_archived,
5738 &chunk_id);
5739 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5740
5741 rotation_state = rotation_id == chunk_id ?
5742 LTTNG_ROTATION_STATE_ONGOING :
5743 LTTNG_ROTATION_STATE_EXPIRED;
5744 } else {
5745 if (session->last_archived_chunk_id.is_set &&
5746 rotation_id != session->last_archived_chunk_id.value) {
5747 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5748 } else {
5749 rotation_state = session->rotation_state;
5750 }
5751 }
5752
5753 switch (rotation_state) {
5754 case LTTNG_ROTATION_STATE_NO_ROTATION:
5755 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5756 session->name);
5757 goto end;
5758 case LTTNG_ROTATION_STATE_EXPIRED:
5759 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
5760 rotation_id, session->name);
5761 break;
5762 case LTTNG_ROTATION_STATE_ONGOING:
5763 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5764 rotation_id, session->name);
5765 break;
5766 case LTTNG_ROTATION_STATE_COMPLETED:
5767 {
5768 int fmt_ret;
5769 char *chunk_path;
5770 char *current_tracing_path_reply;
5771 size_t current_tracing_path_reply_len;
5772
5773 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5774 rotation_id, session->name);
5775
5776 switch (session_get_consumer_destination_type(session)) {
5777 case CONSUMER_DST_LOCAL:
5778 current_tracing_path_reply =
5779 info_return->location.local.absolute_path;
5780 current_tracing_path_reply_len =
5781 sizeof(info_return->location.local.absolute_path);
5782 info_return->location_type =
5783 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5784 fmt_ret = asprintf(&chunk_path,
5785 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5786 session_get_base_path(session),
5787 session->last_archived_chunk_name);
5788 if (fmt_ret == -1) {
5789 PERROR("Failed to format the path of the last archived trace chunk");
5790 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5791 cmd_ret = LTTNG_ERR_UNK;
5792 goto end;
5793 }
5794 break;
5795 case CONSUMER_DST_NET:
5796 {
5797 uint16_t ctrl_port, data_port;
5798
5799 current_tracing_path_reply =
5800 info_return->location.relay.relative_path;
5801 current_tracing_path_reply_len =
5802 sizeof(info_return->location.relay.relative_path);
5803 /* Currently the only supported relay protocol. */
5804 info_return->location.relay.protocol =
5805 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5806
5807 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5808 session_get_net_consumer_hostname(session),
5809 sizeof(info_return->location.relay.host));
5810 if (fmt_ret) {
5811 ERR("Failed to copy host name to rotate_get_info reply");
5812 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5813 cmd_ret = LTTNG_ERR_SET_URL;
5814 goto end;
5815 }
5816
5817 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5818 info_return->location.relay.ports.control = ctrl_port;
5819 info_return->location.relay.ports.data = data_port;
5820 info_return->location_type =
5821 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5822 chunk_path = strdup(session->last_chunk_path);
5823 if (!chunk_path) {
5824 ERR("Failed to allocate the path of the last archived trace chunk");
5825 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5826 cmd_ret = LTTNG_ERR_UNK;
5827 goto end;
5828 }
5829 break;
5830 }
5831 default:
5832 abort();
5833 }
5834
5835 fmt_ret = lttng_strncpy(current_tracing_path_reply,
5836 chunk_path, current_tracing_path_reply_len);
5837 free(chunk_path);
5838 if (fmt_ret) {
5839 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5840 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5841 cmd_ret = LTTNG_ERR_UNK;
5842 goto end;
5843 }
5844
5845 break;
5846 }
5847 case LTTNG_ROTATION_STATE_ERROR:
5848 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
5849 rotation_id, session->name);
5850 break;
5851 default:
5852 abort();
5853 }
5854
5855 cmd_ret = LTTNG_OK;
5856 end:
5857 info_return->status = (int32_t) rotation_state;
5858 return cmd_ret;
5859 }
5860
5861 /*
5862 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5863 *
5864 * Configure the automatic rotation parameters.
5865 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5866 * 'activate' to false means deactivate the rotation schedule and validate that
5867 * 'new_value' has the same value as the currently active value.
5868 *
5869 * Return LTTNG_OK on success or else a positive LTTNG_ERR code.
5870 */
5871 int cmd_rotation_set_schedule(struct ltt_session *session,
5872 bool activate, enum lttng_rotation_schedule_type schedule_type,
5873 uint64_t new_value,
5874 struct notification_thread_handle *notification_thread_handle)
5875 {
5876 int ret;
5877 uint64_t *parameter_value;
5878
5879 LTTNG_ASSERT(session);
5880
5881 DBG("Cmd rotate set schedule session %s", session->name);
5882
5883 if (session->live_timer || !session->output_traces) {
5884 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5885 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5886 goto end;
5887 }
5888
5889 switch (schedule_type) {
5890 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5891 parameter_value = &session->rotate_size;
5892 break;
5893 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5894 parameter_value = &session->rotate_timer_period;
5895 if (new_value >= UINT_MAX) {
5896 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5897 new_value, UINT_MAX);
5898 ret = LTTNG_ERR_INVALID;
5899 goto end;
5900 }
5901 break;
5902 default:
5903 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5904 ret = LTTNG_ERR_INVALID;
5905 goto end;
5906 }
5907
5908 /* Improper use of the API. */
5909 if (new_value == -1ULL) {
5910 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5911 ret = LTTNG_ERR_INVALID;
5912 goto end;
5913 }
5914
5915 /*
5916 * As indicated in struct ltt_session's comments, a value of == 0 means
5917 * this schedule rotation type is not in use.
5918 *
5919 * Reject the command if we were asked to activate a schedule that was
5920 * already active.
5921 */
5922 if (activate && *parameter_value != 0) {
5923 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5924 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5925 goto end;
5926 }
5927
5928 /*
5929 * Reject the command if we were asked to deactivate a schedule that was
5930 * not active.
5931 */
5932 if (!activate && *parameter_value == 0) {
5933 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5934 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5935 goto end;
5936 }
5937
5938 /*
5939 * Reject the command if we were asked to deactivate a schedule that
5940 * doesn't exist.
5941 */
5942 if (!activate && *parameter_value != new_value) {
5943 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5944 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5945 goto end;
5946 }
5947
5948 *parameter_value = activate ? new_value : 0;
5949
5950 switch (schedule_type) {
5951 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5952 if (activate && session->active) {
5953 /*
5954 * Only start the timer if the session is active,
5955 * otherwise it will be started when the session starts.
5956 */
5957 ret = timer_session_rotation_schedule_timer_start(
5958 session, new_value);
5959 if (ret) {
5960 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5961 ret = LTTNG_ERR_UNK;
5962 goto end;
5963 }
5964 } else {
5965 ret = timer_session_rotation_schedule_timer_stop(
5966 session);
5967 if (ret) {
5968 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5969 ret = LTTNG_ERR_UNK;
5970 goto end;
5971 }
5972 }
5973 break;
5974 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5975 if (activate) {
5976 ret = subscribe_session_consumed_size_rotation(session,
5977 new_value, notification_thread_handle);
5978 if (ret) {
5979 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5980 ret = LTTNG_ERR_UNK;
5981 goto end;
5982 }
5983 } else {
5984 ret = unsubscribe_session_consumed_size_rotation(session,
5985 notification_thread_handle);
5986 if (ret) {
5987 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5988 ret = LTTNG_ERR_UNK;
5989 goto end;
5990 }
5991
5992 }
5993 break;
5994 default:
5995 /* Would have been caught before. */
5996 abort();
5997 }
5998
5999 ret = LTTNG_OK;
6000
6001 goto end;
6002
6003 end:
6004 return ret;
6005 }
6006
6007 /* Wait for a given path to be removed before continuing. */
6008 static enum lttng_error_code wait_on_path(void *path_data)
6009 {
6010 const char *shm_path = (const char *) path_data;
6011
6012 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
6013 shm_path);
6014 while (true) {
6015 int ret;
6016 struct stat st;
6017
6018 ret = stat(shm_path, &st);
6019 if (ret) {
6020 if (errno != ENOENT) {
6021 PERROR("stat() returned an error while checking for the existence of the shm path");
6022 } else {
6023 DBG("shm path no longer exists, completing the destruction of session");
6024 }
6025 break;
6026 } else {
6027 if (!S_ISDIR(st.st_mode)) {
6028 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
6029 shm_path);
6030 break;
6031 }
6032 }
6033 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
6034 }
6035 return LTTNG_OK;
6036 }
6037
6038 /*
6039 * Returns a pointer to a handler to run on completion of a command.
6040 * Returns NULL if no handler has to be run for the last command executed.
6041 */
6042 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
6043 {
6044 struct cmd_completion_handler *handler = current_completion_handler;
6045
6046 current_completion_handler = NULL;
6047 return handler;
6048 }
6049
6050 /*
6051 * Init command subsystem.
6052 */
6053 void cmd_init(void)
6054 {
6055 /*
6056 * Set network sequence index to 1 for streams to match a relayd
6057 * socket on the consumer side.
6058 */
6059 pthread_mutex_lock(&relayd_net_seq_idx_lock);
6060 relayd_net_seq_idx = 1;
6061 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
6062
6063 DBG("Command subsystem initialized");
6064 }
LTTng 2.0 tools and control repository
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