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4892e353964aa72fe003966c220085f15b4f6e7d
[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 unsigned int session_id, struct consumer_output *consumer,
921 struct consumer_socket *sock, const char *session_name,
922 const char *hostname, const char *base_path, int session_live_timer,
923 const uint64_t *current_chunk_id, time_t session_creation_time,
924 bool session_name_contains_creation_time)
925 {
926 enum lttng_error_code status = LTTNG_OK;
927
928 LTTNG_ASSERT(consumer);
929 LTTNG_ASSERT(sock);
930
931 /* Sending control relayd socket. */
932 if (!sock->control_sock_sent) {
933 status = send_consumer_relayd_socket(session_id,
934 &consumer->dst.net.control, consumer, sock,
935 session_name, hostname, base_path, session_live_timer,
936 current_chunk_id, session_creation_time,
937 session_name_contains_creation_time);
938 if (status != LTTNG_OK) {
939 goto error;
940 }
941 }
942
943 /* Sending data relayd socket. */
944 if (!sock->data_sock_sent) {
945 status = send_consumer_relayd_socket(session_id,
946 &consumer->dst.net.data, consumer, sock,
947 session_name, hostname, base_path, session_live_timer,
948 current_chunk_id, session_creation_time,
949 session_name_contains_creation_time);
950 if (status != LTTNG_OK) {
951 goto error;
952 }
953 }
954
955 error:
956 return status;
957 }
958
959 /*
960 * Setup relayd connections for a tracing session. First creates the socket to
961 * the relayd and send them to the right domain consumer. Consumer type MUST be
962 * network.
963 */
964 int cmd_setup_relayd(struct ltt_session *session)
965 {
966 int ret = LTTNG_OK;
967 struct ltt_ust_session *usess;
968 struct ltt_kernel_session *ksess;
969 struct consumer_socket *socket;
970 struct lttng_ht_iter iter;
971 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
972
973 LTTNG_ASSERT(session);
974
975 usess = session->ust_session;
976 ksess = session->kernel_session;
977
978 DBG("Setting relayd for session %s", session->name);
979
980 rcu_read_lock();
981 if (session->current_trace_chunk) {
982 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
983 session->current_trace_chunk, &current_chunk_id.value);
984
985 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
986 current_chunk_id.is_set = true;
987 } else {
988 ERR("Failed to get current trace chunk id");
989 ret = LTTNG_ERR_UNK;
990 goto error;
991 }
992 }
993
994 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
995 && usess->consumer->enabled) {
996 /* For each consumer socket, send relayd sockets */
997 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
998 socket, node.node) {
999 pthread_mutex_lock(socket->lock);
1000 ret = send_consumer_relayd_sockets(session->id,
1001 usess->consumer, socket,
1002 session->name, session->hostname,
1003 session->base_path,
1004 session->live_timer,
1005 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1006 session->creation_time,
1007 session->name_contains_creation_time);
1008 pthread_mutex_unlock(socket->lock);
1009 if (ret != LTTNG_OK) {
1010 goto error;
1011 }
1012 /* Session is now ready for network streaming. */
1013 session->net_handle = 1;
1014 }
1015 session->consumer->relay_major_version =
1016 usess->consumer->relay_major_version;
1017 session->consumer->relay_minor_version =
1018 usess->consumer->relay_minor_version;
1019 session->consumer->relay_allows_clear =
1020 usess->consumer->relay_allows_clear;
1021 }
1022
1023 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1024 && ksess->consumer->enabled) {
1025 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1026 socket, node.node) {
1027 pthread_mutex_lock(socket->lock);
1028 ret = send_consumer_relayd_sockets(session->id,
1029 ksess->consumer, socket,
1030 session->name, session->hostname,
1031 session->base_path,
1032 session->live_timer,
1033 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1034 session->creation_time,
1035 session->name_contains_creation_time);
1036 pthread_mutex_unlock(socket->lock);
1037 if (ret != LTTNG_OK) {
1038 goto error;
1039 }
1040 /* Session is now ready for network streaming. */
1041 session->net_handle = 1;
1042 }
1043 session->consumer->relay_major_version =
1044 ksess->consumer->relay_major_version;
1045 session->consumer->relay_minor_version =
1046 ksess->consumer->relay_minor_version;
1047 session->consumer->relay_allows_clear =
1048 ksess->consumer->relay_allows_clear;
1049 }
1050
1051 error:
1052 rcu_read_unlock();
1053 return ret;
1054 }
1055
1056 /*
1057 * Start a kernel session by opening all necessary streams.
1058 */
1059 int start_kernel_session(struct ltt_kernel_session *ksess)
1060 {
1061 int ret;
1062 struct ltt_kernel_channel *kchan;
1063
1064 /* Open kernel metadata */
1065 if (ksess->metadata == NULL && ksess->output_traces) {
1066 ret = kernel_open_metadata(ksess);
1067 if (ret < 0) {
1068 ret = LTTNG_ERR_KERN_META_FAIL;
1069 goto error;
1070 }
1071 }
1072
1073 /* Open kernel metadata stream */
1074 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1075 ret = kernel_open_metadata_stream(ksess);
1076 if (ret < 0) {
1077 ERR("Kernel create metadata stream failed");
1078 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1079 goto error;
1080 }
1081 }
1082
1083 /* For each channel */
1084 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1085 if (kchan->stream_count == 0) {
1086 ret = kernel_open_channel_stream(kchan);
1087 if (ret < 0) {
1088 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1089 goto error;
1090 }
1091 /* Update the stream global counter */
1092 ksess->stream_count_global += ret;
1093 }
1094 }
1095
1096 /* Setup kernel consumer socket and send fds to it */
1097 ret = init_kernel_tracing(ksess);
1098 if (ret != 0) {
1099 ret = LTTNG_ERR_KERN_START_FAIL;
1100 goto error;
1101 }
1102
1103 /* This start the kernel tracing */
1104 ret = kernel_start_session(ksess);
1105 if (ret < 0) {
1106 ret = LTTNG_ERR_KERN_START_FAIL;
1107 goto error;
1108 }
1109
1110 /* Quiescent wait after starting trace */
1111 kernel_wait_quiescent();
1112
1113 ksess->active = 1;
1114
1115 ret = LTTNG_OK;
1116
1117 error:
1118 return ret;
1119 }
1120
1121 int stop_kernel_session(struct ltt_kernel_session *ksess)
1122 {
1123 struct ltt_kernel_channel *kchan;
1124 bool error_occurred = false;
1125 int ret;
1126
1127 if (!ksess || !ksess->active) {
1128 return LTTNG_OK;
1129 }
1130 DBG("Stopping kernel tracing");
1131
1132 ret = kernel_stop_session(ksess);
1133 if (ret < 0) {
1134 ret = LTTNG_ERR_KERN_STOP_FAIL;
1135 goto error;
1136 }
1137
1138 kernel_wait_quiescent();
1139
1140 /* Flush metadata after stopping (if exists) */
1141 if (ksess->metadata_stream_fd >= 0) {
1142 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1143 if (ret < 0) {
1144 ERR("Kernel metadata flush failed");
1145 error_occurred = true;
1146 }
1147 }
1148
1149 /* Flush all buffers after stopping */
1150 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1151 ret = kernel_flush_buffer(kchan);
1152 if (ret < 0) {
1153 ERR("Kernel flush buffer error");
1154 error_occurred = true;
1155 }
1156 }
1157
1158 ksess->active = 0;
1159 if (error_occurred) {
1160 ret = LTTNG_ERR_UNK;
1161 } else {
1162 ret = LTTNG_OK;
1163 }
1164 error:
1165 return ret;
1166 }
1167
1168 /*
1169 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1170 */
1171 int cmd_disable_channel(struct ltt_session *session,
1172 enum lttng_domain_type domain, char *channel_name)
1173 {
1174 int ret;
1175 struct ltt_ust_session *usess;
1176
1177 usess = session->ust_session;
1178
1179 rcu_read_lock();
1180
1181 switch (domain) {
1182 case LTTNG_DOMAIN_KERNEL:
1183 {
1184 ret = channel_kernel_disable(session->kernel_session,
1185 channel_name);
1186 if (ret != LTTNG_OK) {
1187 goto error;
1188 }
1189
1190 kernel_wait_quiescent();
1191 break;
1192 }
1193 case LTTNG_DOMAIN_UST:
1194 {
1195 struct ltt_ust_channel *uchan;
1196 struct lttng_ht *chan_ht;
1197
1198 chan_ht = usess->domain_global.channels;
1199
1200 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1201 if (uchan == NULL) {
1202 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1203 goto error;
1204 }
1205
1206 ret = channel_ust_disable(usess, uchan);
1207 if (ret != LTTNG_OK) {
1208 goto error;
1209 }
1210 break;
1211 }
1212 default:
1213 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1214 goto error;
1215 }
1216
1217 ret = LTTNG_OK;
1218
1219 error:
1220 rcu_read_unlock();
1221 return ret;
1222 }
1223
1224 /*
1225 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1226 *
1227 * The wpipe arguments is used as a notifier for the kernel thread.
1228 */
1229 int cmd_enable_channel(struct command_ctx *cmd_ctx, int sock, int wpipe)
1230 {
1231 int ret;
1232 size_t channel_len;
1233 ssize_t sock_recv_len;
1234 struct lttng_channel *channel = NULL;
1235 struct lttng_buffer_view view;
1236 struct lttng_dynamic_buffer channel_buffer;
1237 const struct lttng_domain command_domain = cmd_ctx->lsm.domain;
1238
1239 lttng_dynamic_buffer_init(&channel_buffer);
1240 channel_len = (size_t) cmd_ctx->lsm.u.channel.length;
1241 ret = lttng_dynamic_buffer_set_size(&channel_buffer, channel_len);
1242 if (ret) {
1243 ret = LTTNG_ERR_NOMEM;
1244 goto end;
1245 }
1246
1247 sock_recv_len = lttcomm_recv_unix_sock(sock, channel_buffer.data,
1248 channel_len);
1249 if (sock_recv_len < 0 || sock_recv_len != channel_len) {
1250 ERR("Failed to receive \"enable channel\" command payload");
1251 ret = LTTNG_ERR_INVALID;
1252 goto end;
1253 }
1254
1255 view = lttng_buffer_view_from_dynamic_buffer(&channel_buffer, 0, channel_len);
1256 if (!lttng_buffer_view_is_valid(&view)) {
1257 ret = LTTNG_ERR_INVALID;
1258 goto end;
1259 }
1260
1261 if (lttng_channel_create_from_buffer(&view, &channel) != channel_len) {
1262 ERR("Invalid channel payload received in \"enable channel\" command");
1263 ret = LTTNG_ERR_INVALID;
1264 goto end;
1265 }
1266
1267 ret = cmd_enable_channel_internal(
1268 cmd_ctx->session, &command_domain, channel, wpipe);
1269
1270 end:
1271 lttng_dynamic_buffer_reset(&channel_buffer);
1272 lttng_channel_destroy(channel);
1273 return ret;
1274 }
1275
1276 static int cmd_enable_channel_internal(struct ltt_session *session,
1277 const struct lttng_domain *domain,
1278 const struct lttng_channel *_attr,
1279 int wpipe)
1280 {
1281 int ret;
1282 struct ltt_ust_session *usess = session->ust_session;
1283 struct lttng_ht *chan_ht;
1284 size_t len;
1285 struct lttng_channel *attr = NULL;
1286
1287 LTTNG_ASSERT(session);
1288 LTTNG_ASSERT(_attr);
1289 LTTNG_ASSERT(domain);
1290
1291 attr = lttng_channel_copy(_attr);
1292 if (!attr) {
1293 ret = LTTNG_ERR_NOMEM;
1294 goto end;
1295 }
1296
1297 len = lttng_strnlen(attr->name, sizeof(attr->name));
1298
1299 /* Validate channel name */
1300 if (attr->name[0] == '.' ||
1301 memchr(attr->name, '/', len) != NULL) {
1302 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1303 goto end;
1304 }
1305
1306 DBG("Enabling channel %s for session %s", attr->name, session->name);
1307
1308 rcu_read_lock();
1309
1310 /*
1311 * If the session is a live session, remove the switch timer, the
1312 * live timer does the same thing but sends also synchronisation
1313 * beacons for inactive streams.
1314 */
1315 if (session->live_timer > 0) {
1316 attr->attr.live_timer_interval = session->live_timer;
1317 attr->attr.switch_timer_interval = 0;
1318 }
1319
1320 /* Check for feature support */
1321 switch (domain->type) {
1322 case LTTNG_DOMAIN_KERNEL:
1323 {
1324 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1325 /* Sampling position of buffer is not supported */
1326 WARN("Kernel tracer does not support buffer monitoring. "
1327 "Setting the monitor interval timer to 0 "
1328 "(disabled) for channel '%s' of session '%s'",
1329 attr->name, session->name);
1330 lttng_channel_set_monitor_timer_interval(attr, 0);
1331 }
1332 break;
1333 }
1334 case LTTNG_DOMAIN_UST:
1335 break;
1336 case LTTNG_DOMAIN_JUL:
1337 case LTTNG_DOMAIN_LOG4J:
1338 case LTTNG_DOMAIN_PYTHON:
1339 if (!agent_tracing_is_enabled()) {
1340 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1341 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1342 goto error;
1343 }
1344 break;
1345 default:
1346 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1347 goto error;
1348 }
1349
1350 switch (domain->type) {
1351 case LTTNG_DOMAIN_KERNEL:
1352 {
1353 struct ltt_kernel_channel *kchan;
1354
1355 kchan = trace_kernel_get_channel_by_name(
1356 attr->name, session->kernel_session);
1357 if (kchan == NULL) {
1358 /*
1359 * Don't try to create a channel if the session has been started at
1360 * some point in time before. The tracer does not allow it.
1361 */
1362 if (session->has_been_started) {
1363 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1364 goto error;
1365 }
1366
1367 if (session->snapshot.nb_output > 0 ||
1368 session->snapshot_mode) {
1369 /* Enforce mmap output for snapshot sessions. */
1370 attr->attr.output = LTTNG_EVENT_MMAP;
1371 }
1372 ret = channel_kernel_create(
1373 session->kernel_session, attr, wpipe);
1374 if (attr->name[0] != '\0') {
1375 session->kernel_session->has_non_default_channel = 1;
1376 }
1377 } else {
1378 ret = channel_kernel_enable(session->kernel_session, kchan);
1379 }
1380
1381 if (ret != LTTNG_OK) {
1382 goto error;
1383 }
1384
1385 kernel_wait_quiescent();
1386 break;
1387 }
1388 case LTTNG_DOMAIN_UST:
1389 case LTTNG_DOMAIN_JUL:
1390 case LTTNG_DOMAIN_LOG4J:
1391 case LTTNG_DOMAIN_PYTHON:
1392 {
1393 struct ltt_ust_channel *uchan;
1394
1395 /*
1396 * FIXME
1397 *
1398 * Current agent implementation limitations force us to allow
1399 * only one channel at once in "agent" subdomains. Each
1400 * subdomain has a default channel name which must be strictly
1401 * adhered to.
1402 */
1403 if (domain->type == LTTNG_DOMAIN_JUL) {
1404 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1405 LTTNG_SYMBOL_NAME_LEN)) {
1406 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1407 goto error;
1408 }
1409 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1410 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1411 LTTNG_SYMBOL_NAME_LEN)) {
1412 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1413 goto error;
1414 }
1415 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1416 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1417 LTTNG_SYMBOL_NAME_LEN)) {
1418 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1419 goto error;
1420 }
1421 }
1422
1423 chan_ht = usess->domain_global.channels;
1424
1425 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1426 if (uchan == NULL) {
1427 /*
1428 * Don't try to create a channel if the session has been started at
1429 * some point in time before. The tracer does not allow it.
1430 */
1431 if (session->has_been_started) {
1432 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1433 goto error;
1434 }
1435
1436 ret = channel_ust_create(usess, attr, domain->buf_type);
1437 if (attr->name[0] != '\0') {
1438 usess->has_non_default_channel = 1;
1439 }
1440 } else {
1441 ret = channel_ust_enable(usess, uchan);
1442 }
1443 break;
1444 }
1445 default:
1446 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1447 goto error;
1448 }
1449
1450 if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1451 session->has_non_mmap_channel = true;
1452 }
1453 error:
1454 rcu_read_unlock();
1455 end:
1456 lttng_channel_destroy(attr);
1457 return ret;
1458 }
1459
1460 enum lttng_error_code cmd_process_attr_tracker_get_tracking_policy(
1461 struct ltt_session *session,
1462 enum lttng_domain_type domain,
1463 enum lttng_process_attr process_attr,
1464 enum lttng_tracking_policy *policy)
1465 {
1466 enum lttng_error_code ret_code = LTTNG_OK;
1467 const struct process_attr_tracker *tracker;
1468
1469 switch (domain) {
1470 case LTTNG_DOMAIN_KERNEL:
1471 if (!session->kernel_session) {
1472 ret_code = LTTNG_ERR_INVALID;
1473 goto end;
1474 }
1475 tracker = kernel_get_process_attr_tracker(
1476 session->kernel_session, process_attr);
1477 break;
1478 case LTTNG_DOMAIN_UST:
1479 if (!session->ust_session) {
1480 ret_code = LTTNG_ERR_INVALID;
1481 goto end;
1482 }
1483 tracker = trace_ust_get_process_attr_tracker(
1484 session->ust_session, process_attr);
1485 break;
1486 default:
1487 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1488 goto end;
1489 }
1490 if (tracker) {
1491 *policy = process_attr_tracker_get_tracking_policy(tracker);
1492 } else {
1493 ret_code = LTTNG_ERR_INVALID;
1494 }
1495 end:
1496 return ret_code;
1497 }
1498
1499 enum lttng_error_code cmd_process_attr_tracker_set_tracking_policy(
1500 struct ltt_session *session,
1501 enum lttng_domain_type domain,
1502 enum lttng_process_attr process_attr,
1503 enum lttng_tracking_policy policy)
1504 {
1505 enum lttng_error_code ret_code = LTTNG_OK;
1506
1507 switch (policy) {
1508 case LTTNG_TRACKING_POLICY_INCLUDE_SET:
1509 case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
1510 case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
1511 break;
1512 default:
1513 ret_code = LTTNG_ERR_INVALID;
1514 goto end;
1515 }
1516
1517 switch (domain) {
1518 case LTTNG_DOMAIN_KERNEL:
1519 if (!session->kernel_session) {
1520 ret_code = LTTNG_ERR_INVALID;
1521 goto end;
1522 }
1523 ret_code = kernel_process_attr_tracker_set_tracking_policy(
1524 session->kernel_session, process_attr, policy);
1525 break;
1526 case LTTNG_DOMAIN_UST:
1527 if (!session->ust_session) {
1528 ret_code = LTTNG_ERR_INVALID;
1529 goto end;
1530 }
1531 ret_code = trace_ust_process_attr_tracker_set_tracking_policy(
1532 session->ust_session, process_attr, policy);
1533 break;
1534 default:
1535 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1536 break;
1537 }
1538 end:
1539 return ret_code;
1540 }
1541
1542 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_add_value(
1543 struct ltt_session *session,
1544 enum lttng_domain_type domain,
1545 enum lttng_process_attr process_attr,
1546 const struct process_attr_value *value)
1547 {
1548 enum lttng_error_code ret_code = LTTNG_OK;
1549
1550 switch (domain) {
1551 case LTTNG_DOMAIN_KERNEL:
1552 if (!session->kernel_session) {
1553 ret_code = LTTNG_ERR_INVALID;
1554 goto end;
1555 }
1556 ret_code = kernel_process_attr_tracker_inclusion_set_add_value(
1557 session->kernel_session, process_attr, value);
1558 break;
1559 case LTTNG_DOMAIN_UST:
1560 if (!session->ust_session) {
1561 ret_code = LTTNG_ERR_INVALID;
1562 goto end;
1563 }
1564 ret_code = trace_ust_process_attr_tracker_inclusion_set_add_value(
1565 session->ust_session, process_attr, value);
1566 break;
1567 default:
1568 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1569 break;
1570 }
1571 end:
1572 return ret_code;
1573 }
1574
1575 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_remove_value(
1576 struct ltt_session *session,
1577 enum lttng_domain_type domain,
1578 enum lttng_process_attr process_attr,
1579 const struct process_attr_value *value)
1580 {
1581 enum lttng_error_code ret_code = LTTNG_OK;
1582
1583 switch (domain) {
1584 case LTTNG_DOMAIN_KERNEL:
1585 if (!session->kernel_session) {
1586 ret_code = LTTNG_ERR_INVALID;
1587 goto end;
1588 }
1589 ret_code = kernel_process_attr_tracker_inclusion_set_remove_value(
1590 session->kernel_session, process_attr, value);
1591 break;
1592 case LTTNG_DOMAIN_UST:
1593 if (!session->ust_session) {
1594 ret_code = LTTNG_ERR_INVALID;
1595 goto end;
1596 }
1597 ret_code = trace_ust_process_attr_tracker_inclusion_set_remove_value(
1598 session->ust_session, process_attr, value);
1599 break;
1600 default:
1601 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1602 break;
1603 }
1604 end:
1605 return ret_code;
1606 }
1607
1608 enum lttng_error_code cmd_process_attr_tracker_get_inclusion_set(
1609 struct ltt_session *session,
1610 enum lttng_domain_type domain,
1611 enum lttng_process_attr process_attr,
1612 struct lttng_process_attr_values **values)
1613 {
1614 enum lttng_error_code ret_code = LTTNG_OK;
1615 const struct process_attr_tracker *tracker;
1616 enum process_attr_tracker_status status;
1617
1618 switch (domain) {
1619 case LTTNG_DOMAIN_KERNEL:
1620 if (!session->kernel_session) {
1621 ret_code = LTTNG_ERR_INVALID;
1622 goto end;
1623 }
1624 tracker = kernel_get_process_attr_tracker(
1625 session->kernel_session, process_attr);
1626 break;
1627 case LTTNG_DOMAIN_UST:
1628 if (!session->ust_session) {
1629 ret_code = LTTNG_ERR_INVALID;
1630 goto end;
1631 }
1632 tracker = trace_ust_get_process_attr_tracker(
1633 session->ust_session, process_attr);
1634 break;
1635 default:
1636 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1637 goto end;
1638 }
1639
1640 if (!tracker) {
1641 ret_code = LTTNG_ERR_INVALID;
1642 goto end;
1643 }
1644
1645 status = process_attr_tracker_get_inclusion_set(tracker, values);
1646 switch (status) {
1647 case PROCESS_ATTR_TRACKER_STATUS_OK:
1648 ret_code = LTTNG_OK;
1649 break;
1650 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1651 ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1652 break;
1653 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1654 ret_code = LTTNG_ERR_NOMEM;
1655 break;
1656 default:
1657 ret_code = LTTNG_ERR_UNK;
1658 break;
1659 }
1660
1661 end:
1662 return ret_code;
1663 }
1664
1665 /*
1666 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1667 */
1668 int cmd_disable_event(struct command_ctx *cmd_ctx,
1669 struct lttng_event *event,
1670 char *filter_expression,
1671 struct lttng_bytecode *bytecode,
1672 struct lttng_event_exclusion *exclusion)
1673 {
1674 int ret;
1675 const char *event_name;
1676 const struct ltt_session *session = cmd_ctx->session;
1677 const char *channel_name = cmd_ctx->lsm.u.disable.channel_name;
1678 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1679
1680 DBG("Disable event command for event \'%s\'", event->name);
1681
1682 /*
1683 * Filter and exclusions are simply not handled by the
1684 * disable event command at this time.
1685 *
1686 * FIXME
1687 */
1688 (void) filter_expression;
1689 (void) exclusion;
1690
1691 /* Ignore the presence of filter or exclusion for the event */
1692 event->filter = 0;
1693 event->exclusion = 0;
1694
1695 event_name = event->name;
1696
1697 /* Error out on unhandled search criteria */
1698 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1699 || event->pid || event->filter || event->exclusion) {
1700 ret = LTTNG_ERR_UNK;
1701 goto error;
1702 }
1703
1704 rcu_read_lock();
1705
1706 switch (domain) {
1707 case LTTNG_DOMAIN_KERNEL:
1708 {
1709 struct ltt_kernel_channel *kchan;
1710 struct ltt_kernel_session *ksess;
1711
1712 ksess = session->kernel_session;
1713
1714 /*
1715 * If a non-default channel has been created in the
1716 * session, explicitely require that -c chan_name needs
1717 * to be provided.
1718 */
1719 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1720 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1721 goto error_unlock;
1722 }
1723
1724 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1725 if (kchan == NULL) {
1726 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1727 goto error_unlock;
1728 }
1729
1730 switch (event->type) {
1731 case LTTNG_EVENT_ALL:
1732 case LTTNG_EVENT_TRACEPOINT:
1733 case LTTNG_EVENT_SYSCALL:
1734 case LTTNG_EVENT_PROBE:
1735 case LTTNG_EVENT_FUNCTION:
1736 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1737 if (event_name[0] == '\0') {
1738 ret = event_kernel_disable_event(kchan,
1739 NULL, event->type);
1740 } else {
1741 ret = event_kernel_disable_event(kchan,
1742 event_name, event->type);
1743 }
1744 if (ret != LTTNG_OK) {
1745 goto error_unlock;
1746 }
1747 break;
1748 default:
1749 ret = LTTNG_ERR_UNK;
1750 goto error_unlock;
1751 }
1752
1753 kernel_wait_quiescent();
1754 break;
1755 }
1756 case LTTNG_DOMAIN_UST:
1757 {
1758 struct ltt_ust_channel *uchan;
1759 struct ltt_ust_session *usess;
1760
1761 usess = session->ust_session;
1762
1763 if (validate_ust_event_name(event_name)) {
1764 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1765 goto error_unlock;
1766 }
1767
1768 /*
1769 * If a non-default channel has been created in the
1770 * session, explicitly require that -c chan_name needs
1771 * to be provided.
1772 */
1773 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1774 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1775 goto error_unlock;
1776 }
1777
1778 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1779 channel_name);
1780 if (uchan == NULL) {
1781 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1782 goto error_unlock;
1783 }
1784
1785 switch (event->type) {
1786 case LTTNG_EVENT_ALL:
1787 /*
1788 * An empty event name means that everything
1789 * should be disabled.
1790 */
1791 if (event->name[0] == '\0') {
1792 ret = event_ust_disable_all_tracepoints(usess, uchan);
1793 } else {
1794 ret = event_ust_disable_tracepoint(usess, uchan,
1795 event_name);
1796 }
1797 if (ret != LTTNG_OK) {
1798 goto error_unlock;
1799 }
1800 break;
1801 default:
1802 ret = LTTNG_ERR_UNK;
1803 goto error_unlock;
1804 }
1805
1806 DBG3("Disable UST event %s in channel %s completed", event_name,
1807 channel_name);
1808 break;
1809 }
1810 case LTTNG_DOMAIN_LOG4J:
1811 case LTTNG_DOMAIN_JUL:
1812 case LTTNG_DOMAIN_PYTHON:
1813 {
1814 struct agent *agt;
1815 struct ltt_ust_session *usess = session->ust_session;
1816
1817 LTTNG_ASSERT(usess);
1818
1819 switch (event->type) {
1820 case LTTNG_EVENT_ALL:
1821 break;
1822 default:
1823 ret = LTTNG_ERR_UNK;
1824 goto error_unlock;
1825 }
1826
1827 agt = trace_ust_find_agent(usess, domain);
1828 if (!agt) {
1829 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1830 goto error_unlock;
1831 }
1832 /*
1833 * An empty event name means that everything
1834 * should be disabled.
1835 */
1836 if (event->name[0] == '\0') {
1837 ret = event_agent_disable_all(usess, agt);
1838 } else {
1839 ret = event_agent_disable(usess, agt, event_name);
1840 }
1841 if (ret != LTTNG_OK) {
1842 goto error_unlock;
1843 }
1844
1845 break;
1846 }
1847 default:
1848 ret = LTTNG_ERR_UND;
1849 goto error_unlock;
1850 }
1851
1852 ret = LTTNG_OK;
1853
1854 error_unlock:
1855 rcu_read_unlock();
1856 error:
1857 free(exclusion);
1858 free(bytecode);
1859 free(filter_expression);
1860 return ret;
1861 }
1862
1863 /*
1864 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1865 */
1866 int cmd_add_context(struct command_ctx *cmd_ctx,
1867 const struct lttng_event_context *event_context, int kwpipe)
1868 {
1869 int ret, chan_kern_created = 0, chan_ust_created = 0;
1870 const enum lttng_domain_type domain = cmd_ctx->lsm.domain.type;
1871 const struct ltt_session *session = cmd_ctx->session;
1872 const char *channel_name = cmd_ctx->lsm.u.context.channel_name;
1873
1874 /*
1875 * Don't try to add a context if the session has been started at
1876 * some point in time before. The tracer does not allow it and would
1877 * result in a corrupted trace.
1878 */
1879 if (cmd_ctx->session->has_been_started) {
1880 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1881 goto end;
1882 }
1883
1884 switch (domain) {
1885 case LTTNG_DOMAIN_KERNEL:
1886 LTTNG_ASSERT(session->kernel_session);
1887
1888 if (session->kernel_session->channel_count == 0) {
1889 /* Create default channel */
1890 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1891 if (ret != LTTNG_OK) {
1892 goto error;
1893 }
1894 chan_kern_created = 1;
1895 }
1896 /* Add kernel context to kernel tracer */
1897 ret = context_kernel_add(session->kernel_session,
1898 event_context, channel_name);
1899 if (ret != LTTNG_OK) {
1900 goto error;
1901 }
1902 break;
1903 case LTTNG_DOMAIN_JUL:
1904 case LTTNG_DOMAIN_LOG4J:
1905 {
1906 /*
1907 * Validate channel name.
1908 * If no channel name is given and the domain is JUL or LOG4J,
1909 * set it to the appropriate domain-specific channel name. If
1910 * a name is provided but does not match the expexted channel
1911 * name, return an error.
1912 */
1913 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1914 strcmp(channel_name,
1915 DEFAULT_JUL_CHANNEL_NAME)) {
1916 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1917 goto error;
1918 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1919 strcmp(channel_name,
1920 DEFAULT_LOG4J_CHANNEL_NAME)) {
1921 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1922 goto error;
1923 }
1924 }
1925 /* fall through */
1926 case LTTNG_DOMAIN_UST:
1927 {
1928 struct ltt_ust_session *usess = session->ust_session;
1929 unsigned int chan_count;
1930
1931 LTTNG_ASSERT(usess);
1932
1933 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1934 if (chan_count == 0) {
1935 struct lttng_channel *attr;
1936 /* Create default channel */
1937 attr = channel_new_default_attr(domain, usess->buffer_type);
1938 if (attr == NULL) {
1939 ret = LTTNG_ERR_FATAL;
1940 goto error;
1941 }
1942
1943 ret = channel_ust_create(usess, attr, usess->buffer_type);
1944 if (ret != LTTNG_OK) {
1945 free(attr);
1946 goto error;
1947 }
1948 channel_attr_destroy(attr);
1949 chan_ust_created = 1;
1950 }
1951
1952 ret = context_ust_add(usess, domain, event_context,
1953 channel_name);
1954 if (ret != LTTNG_OK) {
1955 goto error;
1956 }
1957 break;
1958 }
1959 default:
1960 ret = LTTNG_ERR_UND;
1961 goto error;
1962 }
1963
1964 ret = LTTNG_OK;
1965 goto end;
1966
1967 error:
1968 if (chan_kern_created) {
1969 struct ltt_kernel_channel *kchan =
1970 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1971 session->kernel_session);
1972 /* Created previously, this should NOT fail. */
1973 LTTNG_ASSERT(kchan);
1974 kernel_destroy_channel(kchan);
1975 }
1976
1977 if (chan_ust_created) {
1978 struct ltt_ust_channel *uchan =
1979 trace_ust_find_channel_by_name(
1980 session->ust_session->domain_global.channels,
1981 DEFAULT_CHANNEL_NAME);
1982 /* Created previously, this should NOT fail. */
1983 LTTNG_ASSERT(uchan);
1984 /* Remove from the channel list of the session. */
1985 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1986 uchan);
1987 trace_ust_destroy_channel(uchan);
1988 }
1989 end:
1990 return ret;
1991 }
1992
1993 static inline bool name_starts_with(const char *name, const char *prefix)
1994 {
1995 const size_t max_cmp_len = std::min(strlen(prefix), (size_t) LTTNG_SYMBOL_NAME_LEN);
1996
1997 return !strncmp(name, prefix, max_cmp_len);
1998 }
1999
2000 /* Perform userspace-specific event name validation */
2001 static int validate_ust_event_name(const char *name)
2002 {
2003 int ret = 0;
2004
2005 if (!name) {
2006 ret = -1;
2007 goto end;
2008 }
2009
2010 /*
2011 * Check name against all internal UST event component namespaces used
2012 * by the agents.
2013 */
2014 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2015 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2016 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2017 ret = -1;
2018 }
2019
2020 end:
2021 return ret;
2022 }
2023
2024 /*
2025 * Internal version of cmd_enable_event() with a supplemental
2026 * "internal_event" flag which is used to enable internal events which should
2027 * be hidden from clients. Such events are used in the agent implementation to
2028 * enable the events through which all "agent" events are funeled.
2029 */
2030 static int _cmd_enable_event(struct ltt_session *session,
2031 const struct lttng_domain *domain,
2032 char *channel_name, struct lttng_event *event,
2033 char *filter_expression,
2034 struct lttng_bytecode *filter,
2035 struct lttng_event_exclusion *exclusion,
2036 int wpipe, bool internal_event)
2037 {
2038 int ret = 0, channel_created = 0;
2039 struct lttng_channel *attr = NULL;
2040
2041 LTTNG_ASSERT(session);
2042 LTTNG_ASSERT(event);
2043 LTTNG_ASSERT(channel_name);
2044
2045 /* If we have a filter, we must have its filter expression */
2046 LTTNG_ASSERT(!(!!filter_expression ^ !!filter));
2047
2048 /* Normalize event name as a globbing pattern */
2049 strutils_normalize_star_glob_pattern(event->name);
2050
2051 /* Normalize exclusion names as globbing patterns */
2052 if (exclusion) {
2053 size_t i;
2054
2055 for (i = 0; i < exclusion->count; i++) {
2056 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2057
2058 strutils_normalize_star_glob_pattern(name);
2059 }
2060 }
2061
2062 DBG("Enable event command for event \'%s\'", event->name);
2063
2064 rcu_read_lock();
2065
2066 switch (domain->type) {
2067 case LTTNG_DOMAIN_KERNEL:
2068 {
2069 struct ltt_kernel_channel *kchan;
2070
2071 /*
2072 * If a non-default channel has been created in the
2073 * session, explicitely require that -c chan_name needs
2074 * to be provided.
2075 */
2076 if (session->kernel_session->has_non_default_channel
2077 && channel_name[0] == '\0') {
2078 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2079 goto error;
2080 }
2081
2082 kchan = trace_kernel_get_channel_by_name(channel_name,
2083 session->kernel_session);
2084 if (kchan == NULL) {
2085 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2086 LTTNG_BUFFER_GLOBAL);
2087 if (attr == NULL) {
2088 ret = LTTNG_ERR_FATAL;
2089 goto error;
2090 }
2091 if (lttng_strncpy(attr->name, channel_name,
2092 sizeof(attr->name))) {
2093 ret = LTTNG_ERR_INVALID;
2094 goto error;
2095 }
2096
2097 ret = cmd_enable_channel_internal(
2098 session, domain, attr, wpipe);
2099 if (ret != LTTNG_OK) {
2100 goto error;
2101 }
2102 channel_created = 1;
2103 }
2104
2105 /* Get the newly created kernel channel pointer */
2106 kchan = trace_kernel_get_channel_by_name(channel_name,
2107 session->kernel_session);
2108 if (kchan == NULL) {
2109 /* This sould not happen... */
2110 ret = LTTNG_ERR_FATAL;
2111 goto error;
2112 }
2113
2114 switch (event->type) {
2115 case LTTNG_EVENT_ALL:
2116 {
2117 char *filter_expression_a = NULL;
2118 struct lttng_bytecode *filter_a = NULL;
2119
2120 /*
2121 * We need to duplicate filter_expression and filter,
2122 * because ownership is passed to first enable
2123 * event.
2124 */
2125 if (filter_expression) {
2126 filter_expression_a = strdup(filter_expression);
2127 if (!filter_expression_a) {
2128 ret = LTTNG_ERR_FATAL;
2129 goto error;
2130 }
2131 }
2132 if (filter) {
2133 filter_a = (lttng_bytecode *) zmalloc(sizeof(*filter_a) + filter->len);
2134 if (!filter_a) {
2135 free(filter_expression_a);
2136 ret = LTTNG_ERR_FATAL;
2137 goto error;
2138 }
2139 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2140 }
2141 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2142 ret = event_kernel_enable_event(kchan, event,
2143 filter_expression, filter);
2144 /* We have passed ownership */
2145 filter_expression = NULL;
2146 filter = NULL;
2147 if (ret != LTTNG_OK) {
2148 if (channel_created) {
2149 /* Let's not leak a useless channel. */
2150 kernel_destroy_channel(kchan);
2151 }
2152 free(filter_expression_a);
2153 free(filter_a);
2154 goto error;
2155 }
2156 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2157 ret = event_kernel_enable_event(kchan, event,
2158 filter_expression_a, filter_a);
2159 /* We have passed ownership */
2160 filter_expression_a = NULL;
2161 filter_a = NULL;
2162 if (ret != LTTNG_OK) {
2163 goto error;
2164 }
2165 break;
2166 }
2167 case LTTNG_EVENT_PROBE:
2168 case LTTNG_EVENT_USERSPACE_PROBE:
2169 case LTTNG_EVENT_FUNCTION:
2170 case LTTNG_EVENT_FUNCTION_ENTRY:
2171 case LTTNG_EVENT_TRACEPOINT:
2172 ret = event_kernel_enable_event(kchan, event,
2173 filter_expression, filter);
2174 /* We have passed ownership */
2175 filter_expression = NULL;
2176 filter = NULL;
2177 if (ret != LTTNG_OK) {
2178 if (channel_created) {
2179 /* Let's not leak a useless channel. */
2180 kernel_destroy_channel(kchan);
2181 }
2182 goto error;
2183 }
2184 break;
2185 case LTTNG_EVENT_SYSCALL:
2186 ret = event_kernel_enable_event(kchan, event,
2187 filter_expression, filter);
2188 /* We have passed ownership */
2189 filter_expression = NULL;
2190 filter = NULL;
2191 if (ret != LTTNG_OK) {
2192 goto error;
2193 }
2194 break;
2195 default:
2196 ret = LTTNG_ERR_UNK;
2197 goto error;
2198 }
2199
2200 kernel_wait_quiescent();
2201 break;
2202 }
2203 case LTTNG_DOMAIN_UST:
2204 {
2205 struct ltt_ust_channel *uchan;
2206 struct ltt_ust_session *usess = session->ust_session;
2207
2208 LTTNG_ASSERT(usess);
2209
2210 /*
2211 * If a non-default channel has been created in the
2212 * session, explicitely require that -c chan_name needs
2213 * to be provided.
2214 */
2215 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2216 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2217 goto error;
2218 }
2219
2220 /* Get channel from global UST domain */
2221 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2222 channel_name);
2223 if (uchan == NULL) {
2224 /* Create default channel */
2225 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2226 usess->buffer_type);
2227 if (attr == NULL) {
2228 ret = LTTNG_ERR_FATAL;
2229 goto error;
2230 }
2231 if (lttng_strncpy(attr->name, channel_name,
2232 sizeof(attr->name))) {
2233 ret = LTTNG_ERR_INVALID;
2234 goto error;
2235 }
2236
2237 ret = cmd_enable_channel_internal(
2238 session, domain, attr, wpipe);
2239 if (ret != LTTNG_OK) {
2240 goto error;
2241 }
2242
2243 /* Get the newly created channel reference back */
2244 uchan = trace_ust_find_channel_by_name(
2245 usess->domain_global.channels, channel_name);
2246 LTTNG_ASSERT(uchan);
2247 }
2248
2249 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2250 /*
2251 * Don't allow users to add UST events to channels which
2252 * are assigned to a userspace subdomain (JUL, Log4J,
2253 * Python, etc.).
2254 */
2255 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2256 goto error;
2257 }
2258
2259 if (!internal_event) {
2260 /*
2261 * Ensure the event name is not reserved for internal
2262 * use.
2263 */
2264 ret = validate_ust_event_name(event->name);
2265 if (ret) {
2266 WARN("Userspace event name %s failed validation.",
2267 event->name);
2268 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2269 goto error;
2270 }
2271 }
2272
2273 /* At this point, the session and channel exist on the tracer */
2274 ret = event_ust_enable_tracepoint(usess, uchan, event,
2275 filter_expression, filter, exclusion,
2276 internal_event);
2277 /* We have passed ownership */
2278 filter_expression = NULL;
2279 filter = NULL;
2280 exclusion = NULL;
2281 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2282 goto already_enabled;
2283 } else if (ret != LTTNG_OK) {
2284 goto error;
2285 }
2286 break;
2287 }
2288 case LTTNG_DOMAIN_LOG4J:
2289 case LTTNG_DOMAIN_JUL:
2290 case LTTNG_DOMAIN_PYTHON:
2291 {
2292 const char *default_event_name, *default_chan_name;
2293 struct agent *agt;
2294 struct lttng_event uevent;
2295 struct lttng_domain tmp_dom;
2296 struct ltt_ust_session *usess = session->ust_session;
2297
2298 LTTNG_ASSERT(usess);
2299
2300 if (!agent_tracing_is_enabled()) {
2301 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2302 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2303 goto error;
2304 }
2305
2306 agt = trace_ust_find_agent(usess, domain->type);
2307 if (!agt) {
2308 agt = agent_create(domain->type);
2309 if (!agt) {
2310 ret = LTTNG_ERR_NOMEM;
2311 goto error;
2312 }
2313 agent_add(agt, usess->agents);
2314 }
2315
2316 /* Create the default tracepoint. */
2317 memset(&uevent, 0, sizeof(uevent));
2318 uevent.type = LTTNG_EVENT_TRACEPOINT;
2319 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2320 default_event_name = event_get_default_agent_ust_name(
2321 domain->type);
2322 if (!default_event_name) {
2323 ret = LTTNG_ERR_FATAL;
2324 goto error;
2325 }
2326 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2327 uevent.name[sizeof(uevent.name) - 1] = '\0';
2328
2329 /*
2330 * The domain type is changed because we are about to enable the
2331 * default channel and event for the JUL domain that are hardcoded.
2332 * This happens in the UST domain.
2333 */
2334 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2335 tmp_dom.type = LTTNG_DOMAIN_UST;
2336
2337 switch (domain->type) {
2338 case LTTNG_DOMAIN_LOG4J:
2339 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2340 break;
2341 case LTTNG_DOMAIN_JUL:
2342 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2343 break;
2344 case LTTNG_DOMAIN_PYTHON:
2345 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2346 break;
2347 default:
2348 /* The switch/case we are in makes this impossible */
2349 abort();
2350 }
2351
2352 {
2353 char *filter_expression_copy = NULL;
2354 struct lttng_bytecode *filter_copy = NULL;
2355
2356 if (filter) {
2357 const size_t filter_size = sizeof(
2358 struct lttng_bytecode)
2359 + filter->len;
2360
2361 filter_copy = (lttng_bytecode *) zmalloc(filter_size);
2362 if (!filter_copy) {
2363 ret = LTTNG_ERR_NOMEM;
2364 goto error;
2365 }
2366 memcpy(filter_copy, filter, filter_size);
2367
2368 filter_expression_copy =
2369 strdup(filter_expression);
2370 if (!filter_expression) {
2371 ret = LTTNG_ERR_NOMEM;
2372 }
2373
2374 if (!filter_expression_copy || !filter_copy) {
2375 free(filter_expression_copy);
2376 free(filter_copy);
2377 goto error;
2378 }
2379 }
2380
2381 ret = cmd_enable_event_internal(session, &tmp_dom,
2382 (char *) default_chan_name,
2383 &uevent, filter_expression_copy,
2384 filter_copy, NULL, wpipe);
2385 }
2386
2387 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2388 goto already_enabled;
2389 } else if (ret != LTTNG_OK) {
2390 goto error;
2391 }
2392
2393 /* The wild card * means that everything should be enabled. */
2394 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2395 ret = event_agent_enable_all(usess, agt, event, filter,
2396 filter_expression);
2397 } else {
2398 ret = event_agent_enable(usess, agt, event, filter,
2399 filter_expression);
2400 }
2401 filter = NULL;
2402 filter_expression = NULL;
2403 if (ret != LTTNG_OK) {
2404 goto error;
2405 }
2406
2407 break;
2408 }
2409 default:
2410 ret = LTTNG_ERR_UND;
2411 goto error;
2412 }
2413
2414 ret = LTTNG_OK;
2415
2416 already_enabled:
2417 error:
2418 free(filter_expression);
2419 free(filter);
2420 free(exclusion);
2421 channel_attr_destroy(attr);
2422 rcu_read_unlock();
2423 return ret;
2424 }
2425
2426 /*
2427 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2428 * We own filter, exclusion, and filter_expression.
2429 */
2430 int cmd_enable_event(struct command_ctx *cmd_ctx,
2431 struct lttng_event *event,
2432 char *filter_expression,
2433 struct lttng_event_exclusion *exclusion,
2434 struct lttng_bytecode *bytecode,
2435 int wpipe)
2436 {
2437 int ret;
2438 /*
2439 * Copied to ensure proper alignment since 'lsm' is a packed structure.
2440 */
2441 const lttng_domain command_domain = cmd_ctx->lsm.domain;
2442
2443 /*
2444 * The ownership of the following parameters is transferred to
2445 * _cmd_enable_event:
2446 *
2447 * - filter_expression,
2448 * - bytecode,
2449 * - exclusion
2450 */
2451 ret = _cmd_enable_event(cmd_ctx->session,
2452 &command_domain,
2453 cmd_ctx->lsm.u.enable.channel_name, event,
2454 filter_expression, bytecode, exclusion, wpipe, false);
2455 filter_expression = NULL;
2456 bytecode = NULL;
2457 exclusion = NULL;
2458 return ret;
2459 }
2460
2461 /*
2462 * Enable an event which is internal to LTTng. An internal should
2463 * never be made visible to clients and are immune to checks such as
2464 * reserved names.
2465 */
2466 static int cmd_enable_event_internal(struct ltt_session *session,
2467 const struct lttng_domain *domain,
2468 char *channel_name, struct lttng_event *event,
2469 char *filter_expression,
2470 struct lttng_bytecode *filter,
2471 struct lttng_event_exclusion *exclusion,
2472 int wpipe)
2473 {
2474 return _cmd_enable_event(session, domain, channel_name, event,
2475 filter_expression, filter, exclusion, wpipe, true);
2476 }
2477
2478 /*
2479 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2480 */
2481 enum lttng_error_code cmd_list_tracepoints(enum lttng_domain_type domain,
2482 struct lttng_payload *reply_payload)
2483 {
2484 enum lttng_error_code ret_code;
2485 int ret;
2486 ssize_t i, nb_events = 0;
2487 struct lttng_event *events = NULL;
2488 struct lttcomm_list_command_header reply_command_header = {};
2489 size_t reply_command_header_offset;
2490
2491 assert(reply_payload);
2492
2493 /* Reserve space for command reply header. */
2494 reply_command_header_offset = reply_payload->buffer.size;
2495 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2496 reply_command_header_offset +
2497 sizeof(struct lttcomm_list_command_header));
2498 if (ret) {
2499 ret_code = LTTNG_ERR_NOMEM;
2500 goto error;
2501 }
2502
2503 switch (domain) {
2504 case LTTNG_DOMAIN_KERNEL:
2505 nb_events = kernel_list_events(&events);
2506 if (nb_events < 0) {
2507 ret_code = LTTNG_ERR_KERN_LIST_FAIL;
2508 goto error;
2509 }
2510 break;
2511 case LTTNG_DOMAIN_UST:
2512 nb_events = ust_app_list_events(&events);
2513 if (nb_events < 0) {
2514 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2515 goto error;
2516 }
2517 break;
2518 case LTTNG_DOMAIN_LOG4J:
2519 case LTTNG_DOMAIN_JUL:
2520 case LTTNG_DOMAIN_PYTHON:
2521 nb_events = agent_list_events(&events, domain);
2522 if (nb_events < 0) {
2523 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2524 goto error;
2525 }
2526 break;
2527 default:
2528 ret_code = LTTNG_ERR_UND;
2529 goto error;
2530 }
2531
2532 for (i = 0; i < nb_events; i++) {
2533 ret = lttng_event_serialize(&events[i], 0, NULL, NULL, 0, NULL,
2534 reply_payload);
2535 if (ret) {
2536 ret_code = LTTNG_ERR_NOMEM;
2537 goto error;
2538 }
2539 }
2540
2541 if (nb_events > UINT32_MAX) {
2542 ERR("Tracepoint count would overflow the tracepoint listing command's reply");
2543 ret_code = LTTNG_ERR_OVERFLOW;
2544 goto error;
2545 }
2546
2547 /* Update command reply header. */
2548 reply_command_header.count = (uint32_t) nb_events;
2549 memcpy(reply_payload->buffer.data + reply_command_header_offset, &reply_command_header,
2550 sizeof(reply_command_header));
2551
2552 ret_code = LTTNG_OK;
2553 error:
2554 free(events);
2555 return ret_code;
2556 }
2557
2558 /*
2559 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2560 */
2561 enum lttng_error_code cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2562 struct lttng_payload *reply)
2563 {
2564 enum lttng_error_code ret_code;
2565 int ret;
2566 unsigned int i, nb_fields;
2567 struct lttng_event_field *fields = NULL;
2568 struct lttcomm_list_command_header reply_command_header = {};
2569 size_t reply_command_header_offset;
2570
2571 assert(reply);
2572
2573 /* Reserve space for command reply header. */
2574 reply_command_header_offset = reply->buffer.size;
2575 ret = lttng_dynamic_buffer_set_size(&reply->buffer,
2576 reply_command_header_offset +
2577 sizeof(struct lttcomm_list_command_header));
2578 if (ret) {
2579 ret_code = LTTNG_ERR_NOMEM;
2580 goto error;
2581 }
2582
2583 switch (domain) {
2584 case LTTNG_DOMAIN_UST:
2585 ret = ust_app_list_event_fields(&fields);
2586 if (ret < 0) {
2587 ret_code = LTTNG_ERR_UST_LIST_FAIL;
2588 goto error;
2589 }
2590
2591 break;
2592 case LTTNG_DOMAIN_KERNEL:
2593 default: /* fall-through */
2594 ret_code = LTTNG_ERR_UND;
2595 goto error;
2596 }
2597
2598 nb_fields = ret;
2599
2600 for (i = 0; i < nb_fields; i++) {
2601 ret = lttng_event_field_serialize(&fields[i], reply);
2602 if (ret) {
2603 ret_code = LTTNG_ERR_NOMEM;
2604 goto error;
2605 }
2606 }
2607
2608 if (nb_fields > UINT32_MAX) {
2609 ERR("Tracepoint field count would overflow the tracepoint field listing command's reply");
2610 ret_code = LTTNG_ERR_OVERFLOW;
2611 goto error;
2612 }
2613
2614 /* Update command reply header. */
2615 reply_command_header.count = (uint32_t) nb_fields;
2616
2617 memcpy(reply->buffer.data + reply_command_header_offset, &reply_command_header,
2618 sizeof(reply_command_header));
2619
2620 ret_code = LTTNG_OK;
2621
2622 error:
2623 free(fields);
2624 return ret_code;
2625 }
2626
2627 enum lttng_error_code cmd_list_syscalls(
2628 struct lttng_payload *reply_payload)
2629 {
2630 enum lttng_error_code ret_code;
2631 ssize_t nb_events, i;
2632 int ret;
2633 struct lttng_event *events = NULL;
2634 struct lttcomm_list_command_header reply_command_header = {};
2635 size_t reply_command_header_offset;
2636
2637 assert(reply_payload);
2638
2639 /* Reserve space for command reply header. */
2640 reply_command_header_offset = reply_payload->buffer.size;
2641 ret = lttng_dynamic_buffer_set_size(&reply_payload->buffer,
2642 reply_command_header_offset +
2643 sizeof(struct lttcomm_list_command_header));
2644 if (ret) {
2645 ret_code = LTTNG_ERR_NOMEM;
2646 goto end;
2647 }
2648
2649 nb_events = syscall_table_list(&events);
2650 if (nb_events < 0) {
2651 ret_code = (enum lttng_error_code) -nb_events;
2652 goto end;
2653 }
2654
2655 for (i = 0; i < nb_events; i++) {
2656 ret = lttng_event_serialize(&events[i], 0, NULL, NULL, 0, NULL,
2657 reply_payload);
2658 if (ret) {
2659 ret_code = LTTNG_ERR_NOMEM;
2660 goto end;
2661 }
2662 }
2663
2664 if (nb_events > UINT32_MAX) {
2665 ERR("Syscall count would overflow the syscall listing command's reply");
2666 ret_code = LTTNG_ERR_OVERFLOW;
2667 goto end;
2668 }
2669
2670 /* Update command reply header. */
2671 reply_command_header.count = (uint32_t) nb_events;
2672 memcpy(reply_payload->buffer.data + reply_command_header_offset, &reply_command_header,
2673 sizeof(reply_command_header));
2674
2675 ret_code = LTTNG_OK;
2676 end:
2677 free(events);
2678 return ret_code;
2679 }
2680
2681 /*
2682 * Command LTTNG_START_TRACE processed by the client thread.
2683 *
2684 * Called with session mutex held.
2685 */
2686 int cmd_start_trace(struct ltt_session *session)
2687 {
2688 enum lttng_error_code ret;
2689 unsigned long nb_chan = 0;
2690 struct ltt_kernel_session *ksession;
2691 struct ltt_ust_session *usess;
2692 const bool session_rotated_after_last_stop =
2693 session->rotated_after_last_stop;
2694 const bool session_cleared_after_last_stop =
2695 session->cleared_after_last_stop;
2696
2697 LTTNG_ASSERT(session);
2698
2699 /* Ease our life a bit ;) */
2700 ksession = session->kernel_session;
2701 usess = session->ust_session;
2702
2703 /* Is the session already started? */
2704 if (session->active) {
2705 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2706 /* Perform nothing */
2707 goto end;
2708 }
2709
2710 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2711 !session->current_trace_chunk) {
2712 /*
2713 * A rotation was launched while the session was stopped and
2714 * it has not been completed yet. It is not possible to start
2715 * the session since starting the session here would require a
2716 * rotation from "NULL" to a new trace chunk. That rotation
2717 * would overlap with the ongoing rotation, which is not
2718 * supported.
2719 */
2720 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2721 session->name);
2722 ret = LTTNG_ERR_ROTATION_PENDING;
2723 goto error;
2724 }
2725
2726 /*
2727 * Starting a session without channel is useless since after that it's not
2728 * possible to enable channel thus inform the client.
2729 */
2730 if (usess && usess->domain_global.channels) {
2731 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2732 }
2733 if (ksession) {
2734 nb_chan += ksession->channel_count;
2735 }
2736 if (!nb_chan) {
2737 ret = LTTNG_ERR_NO_CHANNEL;
2738 goto error;
2739 }
2740
2741 session->active = 1;
2742 session->rotated_after_last_stop = false;
2743 session->cleared_after_last_stop = false;
2744 if (session->output_traces && !session->current_trace_chunk) {
2745 if (!session->has_been_started) {
2746 struct lttng_trace_chunk *trace_chunk;
2747
2748 DBG("Creating initial trace chunk of session \"%s\"",
2749 session->name);
2750 trace_chunk = session_create_new_trace_chunk(
2751 session, NULL, NULL, NULL);
2752 if (!trace_chunk) {
2753 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2754 goto error;
2755 }
2756 LTTNG_ASSERT(!session->current_trace_chunk);
2757 ret = (lttng_error_code) session_set_trace_chunk(session, trace_chunk,
2758 NULL);
2759 lttng_trace_chunk_put(trace_chunk);
2760 if (ret) {
2761 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2762 goto error;
2763 }
2764 } else {
2765 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2766 session->name);
2767 /*
2768 * Rotate existing streams into the new chunk.
2769 * This is a "quiet" rotation has no client has
2770 * explicitly requested this operation.
2771 *
2772 * There is also no need to wait for the rotation
2773 * to complete as it will happen immediately. No data
2774 * was produced as the session was stopped, so the
2775 * rotation should happen on reception of the command.
2776 */
2777 ret = (lttng_error_code) cmd_rotate_session(session, NULL, true,
2778 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2779 if (ret != LTTNG_OK) {
2780 goto error;
2781 }
2782 }
2783 }
2784
2785 /* Kernel tracing */
2786 if (ksession != NULL) {
2787 DBG("Start kernel tracing session %s", session->name);
2788 ret = (lttng_error_code) start_kernel_session(ksession);
2789 if (ret != LTTNG_OK) {
2790 goto error;
2791 }
2792 }
2793
2794 /* Flag session that trace should start automatically */
2795 if (usess) {
2796 int int_ret = ust_app_start_trace_all(usess);
2797
2798 if (int_ret < 0) {
2799 ret = LTTNG_ERR_UST_START_FAIL;
2800 goto error;
2801 }
2802 }
2803
2804 /*
2805 * Open a packet in every stream of the session to ensure that viewers
2806 * can correctly identify the boundaries of the periods during which
2807 * tracing was active for this session.
2808 */
2809 ret = session_open_packets(session);
2810 if (ret != LTTNG_OK) {
2811 goto error;
2812 }
2813
2814 /*
2815 * Clear the flag that indicates that a rotation was done while the
2816 * session was stopped.
2817 */
2818 session->rotated_after_last_stop = false;
2819
2820 if (session->rotate_timer_period && !session->rotation_schedule_timer_enabled) {
2821 int int_ret = timer_session_rotation_schedule_timer_start(
2822 session, session->rotate_timer_period);
2823
2824 if (int_ret < 0) {
2825 ERR("Failed to enable rotate timer");
2826 ret = LTTNG_ERR_UNK;
2827 goto error;
2828 }
2829 }
2830
2831 ret = LTTNG_OK;
2832
2833 error:
2834 if (ret == LTTNG_OK) {
2835 /* Flag this after a successful start. */
2836 session->has_been_started |= 1;
2837 } else {
2838 session->active = 0;
2839 /* Restore initial state on error. */
2840 session->rotated_after_last_stop =
2841 session_rotated_after_last_stop;
2842 session->cleared_after_last_stop =
2843 session_cleared_after_last_stop;
2844 }
2845 end:
2846 return ret;
2847 }
2848
2849 /*
2850 * Command LTTNG_STOP_TRACE processed by the client thread.
2851 */
2852 int cmd_stop_trace(struct ltt_session *session)
2853 {
2854 int ret;
2855 struct ltt_kernel_session *ksession;
2856 struct ltt_ust_session *usess;
2857
2858 LTTNG_ASSERT(session);
2859
2860 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2861 /* Short cut */
2862 ksession = session->kernel_session;
2863 usess = session->ust_session;
2864
2865 /* Session is not active. Skip everything and inform the client. */
2866 if (!session->active) {
2867 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2868 goto error;
2869 }
2870
2871 ret = stop_kernel_session(ksession);
2872 if (ret != LTTNG_OK) {
2873 goto error;
2874 }
2875
2876 if (usess && usess->active) {
2877 ret = ust_app_stop_trace_all(usess);
2878 if (ret < 0) {
2879 ret = LTTNG_ERR_UST_STOP_FAIL;
2880 goto error;
2881 }
2882 }
2883
2884 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2885 session->id);
2886 /* Flag inactive after a successful stop. */
2887 session->active = 0;
2888 ret = LTTNG_OK;
2889
2890 error:
2891 return ret;
2892 }
2893
2894 /*
2895 * Set the base_path of the session only if subdir of a control uris is set.
2896 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2897 */
2898 static int set_session_base_path_from_uris(struct ltt_session *session,
2899 size_t nb_uri,
2900 struct lttng_uri *uris)
2901 {
2902 int ret;
2903 size_t i;
2904
2905 for (i = 0; i < nb_uri; i++) {
2906 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2907 uris[i].subdir[0] == '\0') {
2908 /* Not interested in these URIs */
2909 continue;
2910 }
2911
2912 if (session->base_path != NULL) {
2913 free(session->base_path);
2914 session->base_path = NULL;
2915 }
2916
2917 /* Set session base_path */
2918 session->base_path = strdup(uris[i].subdir);
2919 if (!session->base_path) {
2920 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2921 uris[i].subdir, session->name);
2922 ret = LTTNG_ERR_NOMEM;
2923 goto error;
2924 }
2925 DBG2("Setting base path \"%s\" for session \"%s\"",
2926 session->base_path, session->name);
2927 }
2928 ret = LTTNG_OK;
2929 error:
2930 return ret;
2931 }
2932
2933 /*
2934 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2935 */
2936 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2937 struct lttng_uri *uris)
2938 {
2939 int ret, i;
2940 struct ltt_kernel_session *ksess = session->kernel_session;
2941 struct ltt_ust_session *usess = session->ust_session;
2942
2943 LTTNG_ASSERT(session);
2944 LTTNG_ASSERT(uris);
2945 LTTNG_ASSERT(nb_uri > 0);
2946
2947 /* Can't set consumer URI if the session is active. */
2948 if (session->active) {
2949 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2950 goto error;
2951 }
2952
2953 /*
2954 * Set the session base path if any. This is done inside
2955 * cmd_set_consumer_uri to preserve backward compatibility of the
2956 * previous session creation api vs the session descriptor api.
2957 */
2958 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2959 if (ret != LTTNG_OK) {
2960 goto error;
2961 }
2962
2963 /* Set the "global" consumer URIs */
2964 for (i = 0; i < nb_uri; i++) {
2965 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2966 LTTNG_DOMAIN_NONE);
2967 if (ret != LTTNG_OK) {
2968 goto error;
2969 }
2970 }
2971
2972 /* Set UST session URIs */
2973 if (session->ust_session) {
2974 for (i = 0; i < nb_uri; i++) {
2975 ret = add_uri_to_consumer(session,
2976 session->ust_session->consumer,
2977 &uris[i], LTTNG_DOMAIN_UST);
2978 if (ret != LTTNG_OK) {
2979 goto error;
2980 }
2981 }
2982 }
2983
2984 /* Set kernel session URIs */
2985 if (session->kernel_session) {
2986 for (i = 0; i < nb_uri; i++) {
2987 ret = add_uri_to_consumer(session,
2988 session->kernel_session->consumer,
2989 &uris[i], LTTNG_DOMAIN_KERNEL);
2990 if (ret != LTTNG_OK) {
2991 goto error;
2992 }
2993 }
2994 }
2995
2996 /*
2997 * Make sure to set the session in output mode after we set URI since a
2998 * session can be created without URL (thus flagged in no output mode).
2999 */
3000 session->output_traces = 1;
3001 if (ksess) {
3002 ksess->output_traces = 1;
3003 }
3004
3005 if (usess) {
3006 usess->output_traces = 1;
3007 }
3008
3009 /* All good! */
3010 ret = LTTNG_OK;
3011
3012 error:
3013 return ret;
3014 }
3015
3016 static
3017 enum lttng_error_code set_session_output_from_descriptor(
3018 struct ltt_session *session,
3019 const struct lttng_session_descriptor *descriptor)
3020 {
3021 int ret;
3022 enum lttng_error_code ret_code = LTTNG_OK;
3023 enum lttng_session_descriptor_type session_type =
3024 lttng_session_descriptor_get_type(descriptor);
3025 enum lttng_session_descriptor_output_type output_type =
3026 lttng_session_descriptor_get_output_type(descriptor);
3027 struct lttng_uri uris[2] = {};
3028 size_t uri_count = 0;
3029
3030 switch (output_type) {
3031 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
3032 goto end;
3033 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
3034 lttng_session_descriptor_get_local_output_uri(descriptor,
3035 &uris[0]);
3036 uri_count = 1;
3037 break;
3038 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
3039 lttng_session_descriptor_get_network_output_uris(descriptor,
3040 &uris[0], &uris[1]);
3041 uri_count = 2;
3042 break;
3043 default:
3044 ret_code = LTTNG_ERR_INVALID;
3045 goto end;
3046 }
3047
3048 switch (session_type) {
3049 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3050 {
3051 struct snapshot_output *new_output = NULL;
3052
3053 new_output = snapshot_output_alloc();
3054 if (!new_output) {
3055 ret_code = LTTNG_ERR_NOMEM;
3056 goto end;
3057 }
3058
3059 ret = snapshot_output_init_with_uri(session,
3060 DEFAULT_SNAPSHOT_MAX_SIZE,
3061 NULL, uris, uri_count, session->consumer,
3062 new_output, &session->snapshot);
3063 if (ret < 0) {
3064 ret_code = (ret == -ENOMEM) ?
3065 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
3066 snapshot_output_destroy(new_output);
3067 goto end;
3068 }
3069 snapshot_add_output(&session->snapshot, new_output);
3070 break;
3071 }
3072 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3073 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3074 {
3075 ret_code = (lttng_error_code) cmd_set_consumer_uri(session, uri_count, uris);
3076 break;
3077 }
3078 default:
3079 ret_code = LTTNG_ERR_INVALID;
3080 goto end;
3081 }
3082 end:
3083 return ret_code;
3084 }
3085
3086 static
3087 enum lttng_error_code cmd_create_session_from_descriptor(
3088 struct lttng_session_descriptor *descriptor,
3089 const lttng_sock_cred *creds,
3090 const char *home_path)
3091 {
3092 int ret;
3093 enum lttng_error_code ret_code;
3094 const char *session_name;
3095 struct ltt_session *new_session = NULL;
3096 enum lttng_session_descriptor_status descriptor_status;
3097
3098 session_lock_list();
3099 if (home_path) {
3100 if (*home_path != '/') {
3101 ERR("Home path provided by client is not absolute");
3102 ret_code = LTTNG_ERR_INVALID;
3103 goto end;
3104 }
3105 }
3106
3107 descriptor_status = lttng_session_descriptor_get_session_name(
3108 descriptor, &session_name);
3109 switch (descriptor_status) {
3110 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3111 break;
3112 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3113 session_name = NULL;
3114 break;
3115 default:
3116 ret_code = LTTNG_ERR_INVALID;
3117 goto end;
3118 }
3119
3120 ret_code = session_create(session_name, creds->uid, creds->gid,
3121 &new_session);
3122 if (ret_code != LTTNG_OK) {
3123 goto end;
3124 }
3125
3126 if (!session_name) {
3127 ret = lttng_session_descriptor_set_session_name(descriptor,
3128 new_session->name);
3129 if (ret) {
3130 ret_code = LTTNG_ERR_SESSION_FAIL;
3131 goto end;
3132 }
3133 }
3134
3135 if (!lttng_session_descriptor_is_output_destination_initialized(
3136 descriptor)) {
3137 /*
3138 * Only include the session's creation time in the output
3139 * destination if the name of the session itself was
3140 * not auto-generated.
3141 */
3142 ret_code = lttng_session_descriptor_set_default_output(
3143 descriptor,
3144 session_name ? &new_session->creation_time : NULL,
3145 home_path);
3146 if (ret_code != LTTNG_OK) {
3147 goto end;
3148 }
3149 } else {
3150 new_session->has_user_specified_directory =
3151 lttng_session_descriptor_has_output_directory(
3152 descriptor);
3153 }
3154
3155 switch (lttng_session_descriptor_get_type(descriptor)) {
3156 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3157 new_session->snapshot_mode = 1;
3158 break;
3159 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3160 new_session->live_timer =
3161 lttng_session_descriptor_live_get_timer_interval(
3162 descriptor);
3163 break;
3164 default:
3165 break;
3166 }
3167
3168 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3169 if (ret_code != LTTNG_OK) {
3170 goto end;
3171 }
3172 new_session->consumer->enabled = 1;
3173 ret_code = LTTNG_OK;
3174 end:
3175 /* Release reference provided by the session_create function. */
3176 session_put(new_session);
3177 if (ret_code != LTTNG_OK && new_session) {
3178 /* Release the global reference on error. */
3179 session_destroy(new_session);
3180 }
3181 session_unlock_list();
3182 return ret_code;
3183 }
3184
3185 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3186 struct lttng_session_descriptor **return_descriptor)
3187 {
3188 int ret;
3189 size_t payload_size;
3190 struct lttng_dynamic_buffer payload;
3191 struct lttng_buffer_view home_dir_view;
3192 struct lttng_buffer_view session_descriptor_view;
3193 struct lttng_session_descriptor *session_descriptor = NULL;
3194 enum lttng_error_code ret_code;
3195
3196 lttng_dynamic_buffer_init(&payload);
3197 if (cmd_ctx->lsm.u.create_session.home_dir_size >=
3198 LTTNG_PATH_MAX) {
3199 ret_code = LTTNG_ERR_INVALID;
3200 goto error;
3201 }
3202 if (cmd_ctx->lsm.u.create_session.session_descriptor_size >
3203 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3204 ret_code = LTTNG_ERR_INVALID;
3205 goto error;
3206 }
3207
3208 payload_size = cmd_ctx->lsm.u.create_session.home_dir_size +
3209 cmd_ctx->lsm.u.create_session.session_descriptor_size;
3210 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3211 if (ret) {
3212 ret_code = LTTNG_ERR_NOMEM;
3213 goto error;
3214 }
3215
3216 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3217 if (ret <= 0) {
3218 ERR("Reception of session descriptor failed, aborting.");
3219 ret_code = LTTNG_ERR_SESSION_FAIL;
3220 goto error;
3221 }
3222
3223 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3224 &payload,
3225 0,
3226 cmd_ctx->lsm.u.create_session.home_dir_size);
3227 if (cmd_ctx->lsm.u.create_session.home_dir_size > 0 &&
3228 !lttng_buffer_view_is_valid(&home_dir_view)) {
3229 ERR("Invalid payload in \"create session\" command: buffer too short to contain home directory");
3230 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3231 goto error;
3232 }
3233
3234 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3235 &payload,
3236 cmd_ctx->lsm.u.create_session.home_dir_size,
3237 cmd_ctx->lsm.u.create_session.session_descriptor_size);
3238 if (!lttng_buffer_view_is_valid(&session_descriptor_view)) {
3239 ERR("Invalid payload in \"create session\" command: buffer too short to contain session descriptor");
3240 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
3241 goto error;
3242 }
3243
3244 ret = lttng_session_descriptor_create_from_buffer(
3245 &session_descriptor_view, &session_descriptor);
3246 if (ret < 0) {
3247 ERR("Failed to create session descriptor from payload of \"create session\" command");
3248 ret_code = LTTNG_ERR_INVALID;
3249 goto error;
3250 }
3251
3252 /*
3253 * Sets the descriptor's auto-generated properties (name, output) if
3254 * needed.
3255 */
3256 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3257 &cmd_ctx->creds,
3258 home_dir_view.size ? home_dir_view.data : NULL);
3259 if (ret_code != LTTNG_OK) {
3260 goto error;
3261 }
3262
3263 ret_code = LTTNG_OK;
3264 *return_descriptor = session_descriptor;
3265 session_descriptor = NULL;
3266 error:
3267 lttng_dynamic_buffer_reset(&payload);
3268 lttng_session_descriptor_destroy(session_descriptor);
3269 return ret_code;
3270 }
3271
3272 static
3273 void cmd_destroy_session_reply(const struct ltt_session *session,
3274 void *_reply_context)
3275 {
3276 int ret;
3277 ssize_t comm_ret;
3278 const struct cmd_destroy_session_reply_context *reply_context =
3279 (cmd_destroy_session_reply_context *) _reply_context;
3280 struct lttng_dynamic_buffer payload;
3281 struct lttcomm_session_destroy_command_header cmd_header;
3282 struct lttng_trace_archive_location *location = NULL;
3283 struct lttcomm_lttng_msg llm = {
3284 .cmd_type = LTTNG_DESTROY_SESSION,
3285 .ret_code = reply_context->destruction_status,
3286 .pid = UINT32_MAX,
3287 .cmd_header_size =
3288 sizeof(struct lttcomm_session_destroy_command_header),
3289 .data_size = 0,
3290 .fd_count = 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(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 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, 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 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, 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)
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 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 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,
5372 int wait __attribute__((unused)))
5373 {
5374 enum lttng_error_code cmd_ret = LTTNG_OK;
5375 int ret;
5376 unsigned int snapshot_success = 0;
5377 char datetime[16];
5378 struct snapshot_output *tmp_output = NULL;
5379
5380 LTTNG_ASSERT(session);
5381 LTTNG_ASSERT(output);
5382
5383 DBG("Cmd snapshot record for session %s", session->name);
5384
5385 /* Get the datetime for the snapshot output directory. */
5386 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
5387 sizeof(datetime));
5388 if (!ret) {
5389 cmd_ret = LTTNG_ERR_INVALID;
5390 goto error;
5391 }
5392
5393 /*
5394 * Permission denied to create an output if the session is not
5395 * set in no output mode.
5396 */
5397 if (session->output_traces) {
5398 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
5399 goto error;
5400 }
5401
5402 /* The session needs to be started at least once. */
5403 if (!session->has_been_started) {
5404 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5405 goto error;
5406 }
5407
5408 /* Use temporary output for the session. */
5409 if (*output->ctrl_url != '\0') {
5410 tmp_output = snapshot_output_alloc();
5411 if (!tmp_output) {
5412 cmd_ret = LTTNG_ERR_NOMEM;
5413 goto error;
5414 }
5415
5416 ret = snapshot_output_init(session, output->max_size,
5417 output->name,
5418 output->ctrl_url, output->data_url,
5419 session->consumer,
5420 tmp_output, NULL);
5421 if (ret < 0) {
5422 if (ret == -ENOMEM) {
5423 cmd_ret = LTTNG_ERR_NOMEM;
5424 } else {
5425 cmd_ret = LTTNG_ERR_INVALID;
5426 }
5427 goto error;
5428 }
5429 /* Use the global session count for the temporary snapshot. */
5430 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
5431
5432 /* Use the global datetime */
5433 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
5434 cmd_ret = snapshot_record(session, tmp_output);
5435 if (cmd_ret != LTTNG_OK) {
5436 goto error;
5437 }
5438 snapshot_success = 1;
5439 } else {
5440 struct snapshot_output *sout;
5441 struct lttng_ht_iter iter;
5442
5443 rcu_read_lock();
5444 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
5445 &iter.iter, sout, node.node) {
5446 struct snapshot_output output_copy;
5447
5448 /*
5449 * Make a local copy of the output and override output
5450 * parameters with those provided as part of the
5451 * command.
5452 */
5453 memcpy(&output_copy, sout, sizeof(output_copy));
5454
5455 if (output->max_size != (uint64_t) -1ULL) {
5456 output_copy.max_size = output->max_size;
5457 }
5458
5459 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
5460 memcpy(output_copy.datetime, datetime,
5461 sizeof(datetime));
5462
5463 /* Use temporary name. */
5464 if (*output->name != '\0') {
5465 if (lttng_strncpy(output_copy.name,
5466 output->name,
5467 sizeof(output_copy.name))) {
5468 cmd_ret = LTTNG_ERR_INVALID;
5469 rcu_read_unlock();
5470 goto error;
5471 }
5472 }
5473
5474 cmd_ret = snapshot_record(session, &output_copy);
5475 if (cmd_ret != LTTNG_OK) {
5476 rcu_read_unlock();
5477 goto error;
5478 }
5479 snapshot_success = 1;
5480 }
5481 rcu_read_unlock();
5482 }
5483
5484 if (snapshot_success) {
5485 session->snapshot.nb_snapshot++;
5486 } else {
5487 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
5488 }
5489
5490 error:
5491 if (tmp_output) {
5492 snapshot_output_destroy(tmp_output);
5493 }
5494 return cmd_ret;
5495 }
5496
5497 /*
5498 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
5499 */
5500 int cmd_set_session_shm_path(struct ltt_session *session,
5501 const char *shm_path)
5502 {
5503 /* Safety net */
5504 LTTNG_ASSERT(session);
5505
5506 /*
5507 * Can only set shm path before session is started.
5508 */
5509 if (session->has_been_started) {
5510 return LTTNG_ERR_SESSION_STARTED;
5511 }
5512
5513 strncpy(session->shm_path, shm_path,
5514 sizeof(session->shm_path));
5515 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
5516
5517 return LTTNG_OK;
5518 }
5519
5520 /*
5521 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
5522 *
5523 * Ask the consumer to rotate the session output directory.
5524 * The session lock must be held.
5525 *
5526 * Returns LTTNG_OK on success or else a negative LTTng error code.
5527 */
5528 int cmd_rotate_session(struct ltt_session *session,
5529 struct lttng_rotate_session_return *rotate_return,
5530 bool quiet_rotation,
5531 enum lttng_trace_chunk_command_type command)
5532 {
5533 int ret;
5534 uint64_t ongoing_rotation_chunk_id;
5535 enum lttng_error_code cmd_ret = LTTNG_OK;
5536 struct lttng_trace_chunk *chunk_being_archived = NULL;
5537 struct lttng_trace_chunk *new_trace_chunk = NULL;
5538 enum lttng_trace_chunk_status chunk_status;
5539 bool failed_to_rotate = false;
5540 enum lttng_error_code rotation_fail_code = LTTNG_OK;
5541
5542 LTTNG_ASSERT(session);
5543
5544 if (!session->has_been_started) {
5545 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
5546 goto end;
5547 }
5548
5549 /*
5550 * Explicit rotation is not supported for live sessions.
5551 * However, live sessions can perform a quiet rotation on
5552 * destroy.
5553 * Rotation is not supported for snapshot traces (no output).
5554 */
5555 if ((!quiet_rotation && session->live_timer) ||
5556 !session->output_traces) {
5557 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5558 goto end;
5559 }
5560
5561 /* Unsupported feature in lttng-relayd before 2.11. */
5562 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
5563 (session->consumer->relay_major_version == 2 &&
5564 session->consumer->relay_minor_version < 11)) {
5565 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
5566 goto end;
5567 }
5568
5569 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
5570 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
5571 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
5572 goto end;
5573 }
5574
5575 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
5576 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
5577 session->name);
5578 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
5579 goto end;
5580 }
5581
5582 /*
5583 * After a stop, we only allow one rotation to occur, the other ones are
5584 * useless until a new start.
5585 */
5586 if (session->rotated_after_last_stop) {
5587 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
5588 session->name);
5589 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
5590 goto end;
5591 }
5592
5593 /*
5594 * After a stop followed by a clear, disallow following rotations a they would
5595 * generate empty chunks.
5596 */
5597 if (session->cleared_after_last_stop) {
5598 DBG("Session \"%s\" was already cleared after stop, refusing rotation",
5599 session->name);
5600 cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
5601 goto end;
5602 }
5603
5604 if (session->active) {
5605 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
5606 NULL, NULL);
5607 if (!new_trace_chunk) {
5608 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
5609 goto error;
5610 }
5611 }
5612
5613 /*
5614 * The current trace chunk becomes the chunk being archived.
5615 *
5616 * After this point, "chunk_being_archived" must absolutely
5617 * be closed on the consumer(s), otherwise it will never be
5618 * cleaned-up, which will result in a leak.
5619 */
5620 ret = session_set_trace_chunk(session, new_trace_chunk,
5621 &chunk_being_archived);
5622 if (ret) {
5623 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5624 goto error;
5625 }
5626
5627 if (session->kernel_session) {
5628 cmd_ret = kernel_rotate_session(session);
5629 if (cmd_ret != LTTNG_OK) {
5630 failed_to_rotate = true;
5631 rotation_fail_code = cmd_ret;
5632 }
5633 }
5634 if (session->ust_session) {
5635 cmd_ret = ust_app_rotate_session(session);
5636 if (cmd_ret != LTTNG_OK) {
5637 failed_to_rotate = true;
5638 rotation_fail_code = cmd_ret;
5639 }
5640 }
5641
5642 if (!session->active) {
5643 session->rotated_after_last_stop = true;
5644 }
5645
5646 if (!chunk_being_archived) {
5647 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
5648 session->name);
5649 if (failed_to_rotate) {
5650 cmd_ret = rotation_fail_code;
5651 goto error;
5652 }
5653 cmd_ret = LTTNG_OK;
5654 goto end;
5655 }
5656
5657 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5658 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
5659 &ongoing_rotation_chunk_id);
5660 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5661
5662 ret = session_close_trace_chunk(session, chunk_being_archived,
5663 command, session->last_chunk_path);
5664 if (ret) {
5665 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5666 goto error;
5667 }
5668
5669 if (failed_to_rotate) {
5670 cmd_ret = rotation_fail_code;
5671 goto error;
5672 }
5673
5674 session->quiet_rotation = quiet_rotation;
5675 ret = timer_session_rotation_pending_check_start(session,
5676 DEFAULT_ROTATE_PENDING_TIMER);
5677 if (ret) {
5678 cmd_ret = LTTNG_ERR_UNK;
5679 goto error;
5680 }
5681
5682 if (rotate_return) {
5683 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5684 }
5685
5686 session->chunk_being_archived = chunk_being_archived;
5687 chunk_being_archived = NULL;
5688 if (!quiet_rotation) {
5689 ret = notification_thread_command_session_rotation_ongoing(
5690 the_notification_thread_handle, session->name,
5691 session->uid, session->gid,
5692 ongoing_rotation_chunk_id);
5693 if (ret != LTTNG_OK) {
5694 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5695 session->name);
5696 cmd_ret = (lttng_error_code) ret;
5697 }
5698 }
5699
5700 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5701 session->name, ongoing_rotation_chunk_id);
5702 end:
5703 lttng_trace_chunk_put(new_trace_chunk);
5704 lttng_trace_chunk_put(chunk_being_archived);
5705 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5706 return ret;
5707 error:
5708 if (session_reset_rotation_state(session,
5709 LTTNG_ROTATION_STATE_ERROR)) {
5710 ERR("Failed to reset rotation state of session \"%s\"",
5711 session->name);
5712 }
5713 goto end;
5714 }
5715
5716 /*
5717 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5718 *
5719 * Check if the session has finished its rotation.
5720 *
5721 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5722 */
5723 int cmd_rotate_get_info(struct ltt_session *session,
5724 struct lttng_rotation_get_info_return *info_return,
5725 uint64_t rotation_id)
5726 {
5727 enum lttng_error_code cmd_ret = LTTNG_OK;
5728 enum lttng_rotation_state rotation_state;
5729
5730 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
5731 session->most_recent_chunk_id.value);
5732
5733 if (session->chunk_being_archived) {
5734 enum lttng_trace_chunk_status chunk_status;
5735 uint64_t chunk_id;
5736
5737 chunk_status = lttng_trace_chunk_get_id(
5738 session->chunk_being_archived,
5739 &chunk_id);
5740 LTTNG_ASSERT(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5741
5742 rotation_state = rotation_id == chunk_id ?
5743 LTTNG_ROTATION_STATE_ONGOING :
5744 LTTNG_ROTATION_STATE_EXPIRED;
5745 } else {
5746 if (session->last_archived_chunk_id.is_set &&
5747 rotation_id != session->last_archived_chunk_id.value) {
5748 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5749 } else {
5750 rotation_state = session->rotation_state;
5751 }
5752 }
5753
5754 switch (rotation_state) {
5755 case LTTNG_ROTATION_STATE_NO_ROTATION:
5756 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5757 session->name);
5758 goto end;
5759 case LTTNG_ROTATION_STATE_EXPIRED:
5760 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
5761 rotation_id, session->name);
5762 break;
5763 case LTTNG_ROTATION_STATE_ONGOING:
5764 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5765 rotation_id, session->name);
5766 break;
5767 case LTTNG_ROTATION_STATE_COMPLETED:
5768 {
5769 int fmt_ret;
5770 char *chunk_path;
5771 char *current_tracing_path_reply;
5772 size_t current_tracing_path_reply_len;
5773
5774 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5775 rotation_id, session->name);
5776
5777 switch (session_get_consumer_destination_type(session)) {
5778 case CONSUMER_DST_LOCAL:
5779 current_tracing_path_reply =
5780 info_return->location.local.absolute_path;
5781 current_tracing_path_reply_len =
5782 sizeof(info_return->location.local.absolute_path);
5783 info_return->location_type =
5784 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5785 fmt_ret = asprintf(&chunk_path,
5786 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5787 session_get_base_path(session),
5788 session->last_archived_chunk_name);
5789 if (fmt_ret == -1) {
5790 PERROR("Failed to format the path of the last archived trace chunk");
5791 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5792 cmd_ret = LTTNG_ERR_UNK;
5793 goto end;
5794 }
5795 break;
5796 case CONSUMER_DST_NET:
5797 {
5798 uint16_t ctrl_port, data_port;
5799
5800 current_tracing_path_reply =
5801 info_return->location.relay.relative_path;
5802 current_tracing_path_reply_len =
5803 sizeof(info_return->location.relay.relative_path);
5804 /* Currently the only supported relay protocol. */
5805 info_return->location.relay.protocol =
5806 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5807
5808 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5809 session_get_net_consumer_hostname(session),
5810 sizeof(info_return->location.relay.host));
5811 if (fmt_ret) {
5812 ERR("Failed to copy host name to rotate_get_info reply");
5813 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5814 cmd_ret = LTTNG_ERR_SET_URL;
5815 goto end;
5816 }
5817
5818 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5819 info_return->location.relay.ports.control = ctrl_port;
5820 info_return->location.relay.ports.data = data_port;
5821 info_return->location_type =
5822 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5823 chunk_path = strdup(session->last_chunk_path);
5824 if (!chunk_path) {
5825 ERR("Failed to allocate the path of the last archived trace chunk");
5826 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5827 cmd_ret = LTTNG_ERR_UNK;
5828 goto end;
5829 }
5830 break;
5831 }
5832 default:
5833 abort();
5834 }
5835
5836 fmt_ret = lttng_strncpy(current_tracing_path_reply,
5837 chunk_path, current_tracing_path_reply_len);
5838 free(chunk_path);
5839 if (fmt_ret) {
5840 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5841 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5842 cmd_ret = LTTNG_ERR_UNK;
5843 goto end;
5844 }
5845
5846 break;
5847 }
5848 case LTTNG_ROTATION_STATE_ERROR:
5849 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
5850 rotation_id, session->name);
5851 break;
5852 default:
5853 abort();
5854 }
5855
5856 cmd_ret = LTTNG_OK;
5857 end:
5858 info_return->status = (int32_t) rotation_state;
5859 return cmd_ret;
5860 }
5861
5862 /*
5863 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5864 *
5865 * Configure the automatic rotation parameters.
5866 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5867 * 'activate' to false means deactivate the rotation schedule and validate that
5868 * 'new_value' has the same value as the currently active value.
5869 *
5870 * Return LTTNG_OK on success or else a positive LTTNG_ERR code.
5871 */
5872 int cmd_rotation_set_schedule(struct ltt_session *session,
5873 bool activate, enum lttng_rotation_schedule_type schedule_type,
5874 uint64_t new_value,
5875 struct notification_thread_handle *notification_thread_handle)
5876 {
5877 int ret;
5878 uint64_t *parameter_value;
5879
5880 LTTNG_ASSERT(session);
5881
5882 DBG("Cmd rotate set schedule session %s", session->name);
5883
5884 if (session->live_timer || !session->output_traces) {
5885 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5886 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5887 goto end;
5888 }
5889
5890 switch (schedule_type) {
5891 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5892 parameter_value = &session->rotate_size;
5893 break;
5894 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5895 parameter_value = &session->rotate_timer_period;
5896 if (new_value >= UINT_MAX) {
5897 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5898 new_value, UINT_MAX);
5899 ret = LTTNG_ERR_INVALID;
5900 goto end;
5901 }
5902 break;
5903 default:
5904 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5905 ret = LTTNG_ERR_INVALID;
5906 goto end;
5907 }
5908
5909 /* Improper use of the API. */
5910 if (new_value == -1ULL) {
5911 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5912 ret = LTTNG_ERR_INVALID;
5913 goto end;
5914 }
5915
5916 /*
5917 * As indicated in struct ltt_session's comments, a value of == 0 means
5918 * this schedule rotation type is not in use.
5919 *
5920 * Reject the command if we were asked to activate a schedule that was
5921 * already active.
5922 */
5923 if (activate && *parameter_value != 0) {
5924 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5925 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5926 goto end;
5927 }
5928
5929 /*
5930 * Reject the command if we were asked to deactivate a schedule that was
5931 * not active.
5932 */
5933 if (!activate && *parameter_value == 0) {
5934 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5935 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5936 goto end;
5937 }
5938
5939 /*
5940 * Reject the command if we were asked to deactivate a schedule that
5941 * doesn't exist.
5942 */
5943 if (!activate && *parameter_value != new_value) {
5944 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5945 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5946 goto end;
5947 }
5948
5949 *parameter_value = activate ? new_value : 0;
5950
5951 switch (schedule_type) {
5952 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5953 if (activate && session->active) {
5954 /*
5955 * Only start the timer if the session is active,
5956 * otherwise it will be started when the session starts.
5957 */
5958 ret = timer_session_rotation_schedule_timer_start(
5959 session, new_value);
5960 if (ret) {
5961 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5962 ret = LTTNG_ERR_UNK;
5963 goto end;
5964 }
5965 } else {
5966 ret = timer_session_rotation_schedule_timer_stop(
5967 session);
5968 if (ret) {
5969 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5970 ret = LTTNG_ERR_UNK;
5971 goto end;
5972 }
5973 }
5974 break;
5975 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5976 if (activate) {
5977 ret = subscribe_session_consumed_size_rotation(session,
5978 new_value, notification_thread_handle);
5979 if (ret) {
5980 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5981 ret = LTTNG_ERR_UNK;
5982 goto end;
5983 }
5984 } else {
5985 ret = unsubscribe_session_consumed_size_rotation(session,
5986 notification_thread_handle);
5987 if (ret) {
5988 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5989 ret = LTTNG_ERR_UNK;
5990 goto end;
5991 }
5992
5993 }
5994 break;
5995 default:
5996 /* Would have been caught before. */
5997 abort();
5998 }
5999
6000 ret = LTTNG_OK;
6001
6002 goto end;
6003
6004 end:
6005 return ret;
6006 }
6007
6008 /* Wait for a given path to be removed before continuing. */
6009 static enum lttng_error_code wait_on_path(void *path_data)
6010 {
6011 const char *shm_path = (const char *) path_data;
6012
6013 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
6014 shm_path);
6015 while (true) {
6016 int ret;
6017 struct stat st;
6018
6019 ret = stat(shm_path, &st);
6020 if (ret) {
6021 if (errno != ENOENT) {
6022 PERROR("stat() returned an error while checking for the existence of the shm path");
6023 } else {
6024 DBG("shm path no longer exists, completing the destruction of session");
6025 }
6026 break;
6027 } else {
6028 if (!S_ISDIR(st.st_mode)) {
6029 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
6030 shm_path);
6031 break;
6032 }
6033 }
6034 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
6035 }
6036 return LTTNG_OK;
6037 }
6038
6039 /*
6040 * Returns a pointer to a handler to run on completion of a command.
6041 * Returns NULL if no handler has to be run for the last command executed.
6042 */
6043 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
6044 {
6045 struct cmd_completion_handler *handler = current_completion_handler;
6046
6047 current_completion_handler = NULL;
6048 return handler;
6049 }
6050
6051 /*
6052 * Init command subsystem.
6053 */
6054 void cmd_init(void)
6055 {
6056 /*
6057 * Set network sequence index to 1 for streams to match a relayd
6058 * socket on the consumer side.
6059 */
6060 pthread_mutex_lock(&relayd_net_seq_idx_lock);
6061 relayd_net_seq_idx = 1;
6062 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
6063
6064 DBG("Command subsystem initialized");
6065 }
LTTng 2.0 tools and control repository
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