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Fix: list_lttng_agent_events: unbalanced RCU read-side lock on error
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * SPDX-License-Identifier: GPL-2.0-only
6 *
7 */
8
9 #include "bin/lttng-sessiond/tracker.h"
10 #include "lttng/lttng-error.h"
11 #include "lttng/tracker.h"
12 #define _LGPL_SOURCE
13 #include <assert.h>
14 #include <inttypes.h>
15 #include <urcu/list.h>
16 #include <urcu/uatomic.h>
17 #include <sys/stat.h>
18 #include <stdio.h>
19
20 #include <common/defaults.h>
21 #include <common/common.h>
22 #include <common/sessiond-comm/sessiond-comm.h>
23 #include <common/relayd/relayd.h>
24 #include <common/utils.h>
25 #include <common/compat/string.h>
26 #include <common/kernel-ctl/kernel-ctl.h>
27 #include <common/dynamic-buffer.h>
28 #include <common/buffer-view.h>
29 #include <common/trace-chunk.h>
30 #include <lttng/location-internal.h>
31 #include <lttng/trigger/trigger-internal.h>
32 #include <lttng/condition/condition.h>
33 #include <lttng/action/action.h>
34 #include <lttng/channel.h>
35 #include <lttng/channel-internal.h>
36 #include <lttng/rotate-internal.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/session-internal.h>
39 #include <lttng/userspace-probe-internal.h>
40 #include <lttng/session-descriptor-internal.h>
41 #include <common/string-utils/string-utils.h>
42
43 #include "channel.h"
44 #include "consumer.h"
45 #include "event.h"
46 #include "health-sessiond.h"
47 #include "kernel.h"
48 #include "kernel-consumer.h"
49 #include "lttng-sessiond.h"
50 #include "utils.h"
51 #include "lttng-syscall.h"
52 #include "agent.h"
53 #include "buffer-registry.h"
54 #include "notification-thread.h"
55 #include "notification-thread-commands.h"
56 #include "rotate.h"
57 #include "rotation-thread.h"
58 #include "timer.h"
59 #include "agent-thread.h"
60
61 #include "cmd.h"
62
63 /* Sleep for 100ms between each check for the shm path's deletion. */
64 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
65
66 struct cmd_destroy_session_reply_context {
67 int reply_sock_fd;
68 bool implicit_rotation_on_destroy;
69 /*
70 * Indicates whether or not an error occurred while launching the
71 * destruction of a session.
72 */
73 enum lttng_error_code destruction_status;
74 };
75
76 static enum lttng_error_code wait_on_path(void *path);
77
78 /*
79 * Command completion handler that is used by the destroy command
80 * when a session that has a non-default shm_path is being destroyed.
81 *
82 * See comment in cmd_destroy_session() for the rationale.
83 */
84 static struct destroy_completion_handler {
85 struct cmd_completion_handler handler;
86 char shm_path[member_sizeof(struct ltt_session, shm_path)];
87 } destroy_completion_handler = {
88 .handler = {
89 .run = wait_on_path,
90 .data = destroy_completion_handler.shm_path
91 },
92 .shm_path = { 0 },
93 };
94
95 static struct cmd_completion_handler *current_completion_handler;
96
97 /*
98 * Used to keep a unique index for each relayd socket created where this value
99 * is associated with streams on the consumer so it can match the right relayd
100 * to send to. It must be accessed with the relayd_net_seq_idx_lock
101 * held.
102 */
103 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
104 static uint64_t relayd_net_seq_idx;
105
106 static int validate_ust_event_name(const char *);
107 static int cmd_enable_event_internal(struct ltt_session *session,
108 const struct lttng_domain *domain,
109 char *channel_name, struct lttng_event *event,
110 char *filter_expression,
111 struct lttng_filter_bytecode *filter,
112 struct lttng_event_exclusion *exclusion,
113 int wpipe);
114
115 /*
116 * Create a session path used by list_lttng_sessions for the case that the
117 * session consumer is on the network.
118 */
119 static int build_network_session_path(char *dst, size_t size,
120 struct ltt_session *session)
121 {
122 int ret, kdata_port, udata_port;
123 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
124 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
125
126 assert(session);
127 assert(dst);
128
129 memset(tmp_urls, 0, sizeof(tmp_urls));
130 memset(tmp_uurl, 0, sizeof(tmp_uurl));
131
132 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
133
134 if (session->kernel_session && session->kernel_session->consumer) {
135 kuri = &session->kernel_session->consumer->dst.net.control;
136 kdata_port = session->kernel_session->consumer->dst.net.data.port;
137 }
138
139 if (session->ust_session && session->ust_session->consumer) {
140 uuri = &session->ust_session->consumer->dst.net.control;
141 udata_port = session->ust_session->consumer->dst.net.data.port;
142 }
143
144 if (uuri == NULL && kuri == NULL) {
145 uri = &session->consumer->dst.net.control;
146 kdata_port = session->consumer->dst.net.data.port;
147 } else if (kuri && uuri) {
148 ret = uri_compare(kuri, uuri);
149 if (ret) {
150 /* Not Equal */
151 uri = kuri;
152 /* Build uuri URL string */
153 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
154 if (ret < 0) {
155 goto error;
156 }
157 } else {
158 uri = kuri;
159 }
160 } else if (kuri && uuri == NULL) {
161 uri = kuri;
162 } else if (uuri && kuri == NULL) {
163 uri = uuri;
164 }
165
166 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
167 if (ret < 0) {
168 goto error;
169 }
170
171 /*
172 * Do we have a UST url set. If yes, this means we have both kernel and UST
173 * to print.
174 */
175 if (*tmp_uurl != '\0') {
176 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
177 tmp_urls, kdata_port, tmp_uurl, udata_port);
178 } else {
179 int dport;
180 if (kuri || (!kuri && !uuri)) {
181 dport = kdata_port;
182 } else {
183 /* No kernel URI, use the UST port. */
184 dport = udata_port;
185 }
186 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
187 }
188
189 error:
190 return ret;
191 }
192
193 /*
194 * Get run-time attributes if the session has been started (discarded events,
195 * lost packets).
196 */
197 static int get_kernel_runtime_stats(struct ltt_session *session,
198 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
199 uint64_t *lost_packets)
200 {
201 int ret;
202
203 if (!session->has_been_started) {
204 ret = 0;
205 *discarded_events = 0;
206 *lost_packets = 0;
207 goto end;
208 }
209
210 ret = consumer_get_discarded_events(session->id, kchan->key,
211 session->kernel_session->consumer,
212 discarded_events);
213 if (ret < 0) {
214 goto end;
215 }
216
217 ret = consumer_get_lost_packets(session->id, kchan->key,
218 session->kernel_session->consumer,
219 lost_packets);
220 if (ret < 0) {
221 goto end;
222 }
223
224 end:
225 return ret;
226 }
227
228 /*
229 * Get run-time attributes if the session has been started (discarded events,
230 * lost packets).
231 */
232 static int get_ust_runtime_stats(struct ltt_session *session,
233 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
234 uint64_t *lost_packets)
235 {
236 int ret;
237 struct ltt_ust_session *usess;
238
239 if (!discarded_events || !lost_packets) {
240 ret = -1;
241 goto end;
242 }
243
244 usess = session->ust_session;
245 assert(discarded_events);
246 assert(lost_packets);
247
248 if (!usess || !session->has_been_started) {
249 *discarded_events = 0;
250 *lost_packets = 0;
251 ret = 0;
252 goto end;
253 }
254
255 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
256 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
257 &usess->buffer_reg_uid_list,
258 usess->consumer, uchan->id,
259 uchan->attr.overwrite,
260 discarded_events,
261 lost_packets);
262 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
263 ret = ust_app_pid_get_channel_runtime_stats(usess,
264 uchan, usess->consumer,
265 uchan->attr.overwrite,
266 discarded_events,
267 lost_packets);
268 if (ret < 0) {
269 goto end;
270 }
271 *discarded_events += uchan->per_pid_closed_app_discarded;
272 *lost_packets += uchan->per_pid_closed_app_lost;
273 } else {
274 ERR("Unsupported buffer type");
275 assert(0);
276 ret = -1;
277 goto end;
278 }
279
280 end:
281 return ret;
282 }
283
284 /*
285 * Fill lttng_channel array of all channels.
286 */
287 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
288 struct ltt_session *session, struct lttng_channel *channels,
289 struct lttng_channel_extended *chan_exts)
290 {
291 int i = 0, ret = 0;
292 struct ltt_kernel_channel *kchan;
293
294 DBG("Listing channels for session %s", session->name);
295
296 switch (domain) {
297 case LTTNG_DOMAIN_KERNEL:
298 /* Kernel channels */
299 if (session->kernel_session != NULL) {
300 cds_list_for_each_entry(kchan,
301 &session->kernel_session->channel_list.head, list) {
302 uint64_t discarded_events, lost_packets;
303 struct lttng_channel_extended *extended;
304
305 extended = (struct lttng_channel_extended *)
306 kchan->channel->attr.extended.ptr;
307
308 ret = get_kernel_runtime_stats(session, kchan,
309 &discarded_events, &lost_packets);
310 if (ret < 0) {
311 goto end;
312 }
313 /* Copy lttng_channel struct to array */
314 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
315 channels[i].enabled = kchan->enabled;
316 chan_exts[i].discarded_events =
317 discarded_events;
318 chan_exts[i].lost_packets = lost_packets;
319 chan_exts[i].monitor_timer_interval =
320 extended->monitor_timer_interval;
321 chan_exts[i].blocking_timeout = 0;
322 i++;
323 }
324 }
325 break;
326 case LTTNG_DOMAIN_UST:
327 {
328 struct lttng_ht_iter iter;
329 struct ltt_ust_channel *uchan;
330
331 rcu_read_lock();
332 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
333 &iter.iter, uchan, node.node) {
334 uint64_t discarded_events = 0, lost_packets = 0;
335
336 if (lttng_strncpy(channels[i].name, uchan->name,
337 LTTNG_SYMBOL_NAME_LEN)) {
338 break;
339 }
340 channels[i].attr.overwrite = uchan->attr.overwrite;
341 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
342 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
343 channels[i].attr.switch_timer_interval =
344 uchan->attr.switch_timer_interval;
345 channels[i].attr.read_timer_interval =
346 uchan->attr.read_timer_interval;
347 channels[i].enabled = uchan->enabled;
348 channels[i].attr.tracefile_size = uchan->tracefile_size;
349 channels[i].attr.tracefile_count = uchan->tracefile_count;
350
351 /*
352 * Map enum lttng_ust_output to enum lttng_event_output.
353 */
354 switch (uchan->attr.output) {
355 case LTTNG_UST_MMAP:
356 channels[i].attr.output = LTTNG_EVENT_MMAP;
357 break;
358 default:
359 /*
360 * LTTNG_UST_MMAP is the only supported UST
361 * output mode.
362 */
363 assert(0);
364 break;
365 }
366
367 chan_exts[i].monitor_timer_interval =
368 uchan->monitor_timer_interval;
369 chan_exts[i].blocking_timeout =
370 uchan->attr.u.s.blocking_timeout;
371
372 ret = get_ust_runtime_stats(session, uchan,
373 &discarded_events, &lost_packets);
374 if (ret < 0) {
375 break;
376 }
377 chan_exts[i].discarded_events = discarded_events;
378 chan_exts[i].lost_packets = lost_packets;
379 i++;
380 }
381 rcu_read_unlock();
382 break;
383 }
384 default:
385 break;
386 }
387
388 end:
389 if (ret < 0) {
390 return -LTTNG_ERR_FATAL;
391 } else {
392 return LTTNG_OK;
393 }
394 }
395
396 static int increment_extended_len(const char *filter_expression,
397 struct lttng_event_exclusion *exclusion,
398 const struct lttng_userspace_probe_location *probe_location,
399 size_t *extended_len)
400 {
401 int ret = 0;
402
403 *extended_len += sizeof(struct lttcomm_event_extended_header);
404
405 if (filter_expression) {
406 *extended_len += strlen(filter_expression) + 1;
407 }
408
409 if (exclusion) {
410 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
411 }
412
413 if (probe_location) {
414 ret = lttng_userspace_probe_location_serialize(probe_location,
415 NULL, NULL);
416 if (ret < 0) {
417 goto end;
418 }
419 *extended_len += ret;
420 }
421 ret = 0;
422 end:
423 return ret;
424 }
425
426 static int append_extended_info(const char *filter_expression,
427 struct lttng_event_exclusion *exclusion,
428 struct lttng_userspace_probe_location *probe_location,
429 void **extended_at)
430 {
431 int ret = 0;
432 size_t filter_len = 0;
433 size_t nb_exclusions = 0;
434 size_t userspace_probe_location_len = 0;
435 struct lttng_dynamic_buffer location_buffer;
436 struct lttcomm_event_extended_header extended_header;
437
438 if (filter_expression) {
439 filter_len = strlen(filter_expression) + 1;
440 }
441
442 if (exclusion) {
443 nb_exclusions = exclusion->count;
444 }
445
446 if (probe_location) {
447 lttng_dynamic_buffer_init(&location_buffer);
448 ret = lttng_userspace_probe_location_serialize(probe_location,
449 &location_buffer, NULL);
450 if (ret < 0) {
451 ret = -1;
452 goto end;
453 }
454 userspace_probe_location_len = location_buffer.size;
455 }
456
457 /* Set header fields */
458 extended_header.filter_len = filter_len;
459 extended_header.nb_exclusions = nb_exclusions;
460 extended_header.userspace_probe_location_len = userspace_probe_location_len;
461
462 /* Copy header */
463 memcpy(*extended_at, &extended_header, sizeof(extended_header));
464 *extended_at += sizeof(extended_header);
465
466 /* Copy filter string */
467 if (filter_expression) {
468 memcpy(*extended_at, filter_expression, filter_len);
469 *extended_at += filter_len;
470 }
471
472 /* Copy exclusion names */
473 if (exclusion) {
474 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
475
476 memcpy(*extended_at, &exclusion->names, len);
477 *extended_at += len;
478 }
479
480 if (probe_location) {
481 memcpy(*extended_at, location_buffer.data, location_buffer.size);
482 *extended_at += location_buffer.size;
483 lttng_dynamic_buffer_reset(&location_buffer);
484 }
485 ret = 0;
486 end:
487 return ret;
488 }
489
490 /*
491 * Create a list of agent domain events.
492 *
493 * Return number of events in list on success or else a negative value.
494 */
495 static int list_lttng_agent_events(struct agent *agt,
496 struct lttng_event **events, size_t *total_size)
497 {
498 int i = 0, ret = 0;
499 unsigned int nb_event = 0;
500 struct agent_event *event;
501 struct lttng_event *tmp_events = NULL;
502 struct lttng_ht_iter iter;
503 size_t extended_len = 0;
504 void *extended_at;
505
506 assert(agt);
507 assert(events);
508
509 DBG3("Listing agent events");
510
511 rcu_read_lock();
512 nb_event = lttng_ht_get_count(agt->events);
513 if (nb_event == 0) {
514 ret = nb_event;
515 *total_size = 0;
516 goto error;
517 }
518
519 /* Compute required extended infos size */
520 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
521
522 /*
523 * This is only valid because the commands which add events are
524 * processed in the same thread as the listing.
525 */
526 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
527 ret = increment_extended_len(event->filter_expression, NULL, NULL,
528 &extended_len);
529 if (ret) {
530 DBG("Error computing the length of extended info message");
531 ret = -LTTNG_ERR_FATAL;
532 goto error;
533 }
534 }
535
536 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
537 tmp_events = zmalloc(*total_size);
538 if (!tmp_events) {
539 PERROR("zmalloc agent events session");
540 ret = -LTTNG_ERR_FATAL;
541 goto error;
542 }
543
544 extended_at = ((uint8_t *) tmp_events) +
545 nb_event * sizeof(struct lttng_event);
546
547 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
548 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
549 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
550 tmp_events[i].enabled = event->enabled;
551 tmp_events[i].loglevel = event->loglevel_value;
552 tmp_events[i].loglevel_type = event->loglevel_type;
553 i++;
554
555 /* Append extended info */
556 ret = append_extended_info(event->filter_expression, NULL, NULL,
557 &extended_at);
558 if (ret) {
559 DBG("Error appending extended info message");
560 ret = -LTTNG_ERR_FATAL;
561 goto error;
562 }
563 }
564
565 *events = tmp_events;
566 ret = nb_event;
567 assert(nb_event == i);
568
569 end:
570 rcu_read_unlock();
571 return ret;
572 error:
573 free(tmp_events);
574 goto end;
575 }
576
577 /*
578 * Create a list of ust global domain events.
579 */
580 static int list_lttng_ust_global_events(char *channel_name,
581 struct ltt_ust_domain_global *ust_global,
582 struct lttng_event **events, size_t *total_size)
583 {
584 int i = 0, ret = 0;
585 unsigned int nb_event = 0;
586 struct lttng_ht_iter iter;
587 struct lttng_ht_node_str *node;
588 struct ltt_ust_channel *uchan;
589 struct ltt_ust_event *uevent;
590 struct lttng_event *tmp;
591 size_t extended_len = 0;
592 void *extended_at;
593
594 DBG("Listing UST global events for channel %s", channel_name);
595
596 rcu_read_lock();
597
598 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
599 node = lttng_ht_iter_get_node_str(&iter);
600 if (node == NULL) {
601 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
602 goto end;
603 }
604
605 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
606
607 nb_event = lttng_ht_get_count(uchan->events);
608 if (nb_event == 0) {
609 ret = nb_event;
610 *total_size = 0;
611 goto end;
612 }
613
614 DBG3("Listing UST global %d events", nb_event);
615
616 /* Compute required extended infos size */
617 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
618 if (uevent->internal) {
619 nb_event--;
620 continue;
621 }
622
623 ret = increment_extended_len(uevent->filter_expression,
624 uevent->exclusion, NULL, &extended_len);
625 if (ret) {
626 DBG("Error computing the length of extended info message");
627 ret = -LTTNG_ERR_FATAL;
628 goto end;
629 }
630 }
631 if (nb_event == 0) {
632 /* All events are internal, skip. */
633 ret = 0;
634 *total_size = 0;
635 goto end;
636 }
637
638 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
639 tmp = zmalloc(*total_size);
640 if (tmp == NULL) {
641 ret = -LTTNG_ERR_FATAL;
642 goto end;
643 }
644
645 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
646
647 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
648 if (uevent->internal) {
649 /* This event should remain hidden from clients */
650 continue;
651 }
652 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
653 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
654 tmp[i].enabled = uevent->enabled;
655
656 switch (uevent->attr.instrumentation) {
657 case LTTNG_UST_TRACEPOINT:
658 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
659 break;
660 case LTTNG_UST_PROBE:
661 tmp[i].type = LTTNG_EVENT_PROBE;
662 break;
663 case LTTNG_UST_FUNCTION:
664 tmp[i].type = LTTNG_EVENT_FUNCTION;
665 break;
666 }
667
668 tmp[i].loglevel = uevent->attr.loglevel;
669 switch (uevent->attr.loglevel_type) {
670 case LTTNG_UST_LOGLEVEL_ALL:
671 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
672 break;
673 case LTTNG_UST_LOGLEVEL_RANGE:
674 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
675 break;
676 case LTTNG_UST_LOGLEVEL_SINGLE:
677 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
678 break;
679 }
680 if (uevent->filter) {
681 tmp[i].filter = 1;
682 }
683 if (uevent->exclusion) {
684 tmp[i].exclusion = 1;
685 }
686 i++;
687
688 /* Append extended info */
689 ret = append_extended_info(uevent->filter_expression,
690 uevent->exclusion, NULL, &extended_at);
691 if (ret) {
692 DBG("Error appending extended info message");
693 ret = -LTTNG_ERR_FATAL;
694 goto end;
695 }
696 }
697
698 ret = nb_event;
699 *events = tmp;
700 end:
701 rcu_read_unlock();
702 return ret;
703 }
704
705 /*
706 * Fill lttng_event array of all kernel events in the channel.
707 */
708 static int list_lttng_kernel_events(char *channel_name,
709 struct ltt_kernel_session *kernel_session,
710 struct lttng_event **events, size_t *total_size)
711 {
712 int i = 0, ret;
713 unsigned int nb_event;
714 struct ltt_kernel_event *event;
715 struct ltt_kernel_channel *kchan;
716 size_t extended_len = 0;
717 void *extended_at;
718
719 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
720 if (kchan == NULL) {
721 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
722 goto error;
723 }
724
725 nb_event = kchan->event_count;
726
727 DBG("Listing events for channel %s", kchan->channel->name);
728
729 if (nb_event == 0) {
730 *total_size = 0;
731 *events = NULL;
732 goto end;
733 }
734
735 /* Compute required extended infos size */
736 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
737 ret = increment_extended_len(event->filter_expression, NULL,
738 event->userspace_probe_location,
739 &extended_len);
740 if (ret) {
741 DBG("Error computing the length of extended info message");
742 ret = -LTTNG_ERR_FATAL;
743 goto error;
744 }
745 }
746
747 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
748 *events = zmalloc(*total_size);
749 if (*events == NULL) {
750 ret = -LTTNG_ERR_FATAL;
751 goto error;
752 }
753
754 extended_at = ((void *) *events) +
755 nb_event * sizeof(struct lttng_event);
756
757 /* Kernel channels */
758 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
759 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
760 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
761 (*events)[i].enabled = event->enabled;
762 (*events)[i].filter =
763 (unsigned char) !!event->filter_expression;
764
765 switch (event->event->instrumentation) {
766 case LTTNG_KERNEL_TRACEPOINT:
767 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
768 break;
769 case LTTNG_KERNEL_KRETPROBE:
770 (*events)[i].type = LTTNG_EVENT_FUNCTION;
771 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
772 sizeof(struct lttng_kernel_kprobe));
773 break;
774 case LTTNG_KERNEL_KPROBE:
775 (*events)[i].type = LTTNG_EVENT_PROBE;
776 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
777 sizeof(struct lttng_kernel_kprobe));
778 break;
779 case LTTNG_KERNEL_UPROBE:
780 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
781 break;
782 case LTTNG_KERNEL_FUNCTION:
783 (*events)[i].type = LTTNG_EVENT_FUNCTION;
784 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
785 sizeof(struct lttng_kernel_function));
786 break;
787 case LTTNG_KERNEL_NOOP:
788 (*events)[i].type = LTTNG_EVENT_NOOP;
789 break;
790 case LTTNG_KERNEL_SYSCALL:
791 (*events)[i].type = LTTNG_EVENT_SYSCALL;
792 break;
793 case LTTNG_KERNEL_ALL:
794 /* fall-through. */
795 default:
796 assert(0);
797 break;
798 }
799 i++;
800
801 /* Append extended info */
802 ret = append_extended_info(event->filter_expression, NULL,
803 event->userspace_probe_location, &extended_at);
804 if (ret) {
805 DBG("Error appending extended info message");
806 ret = -LTTNG_ERR_FATAL;
807 goto error;
808 }
809 }
810
811 end:
812 return nb_event;
813
814 error:
815 return ret;
816 }
817
818 /*
819 * Add URI so the consumer output object. Set the correct path depending on the
820 * domain adding the default trace directory.
821 */
822 static enum lttng_error_code add_uri_to_consumer(
823 const struct ltt_session *session,
824 struct consumer_output *consumer,
825 struct lttng_uri *uri, enum lttng_domain_type domain)
826 {
827 int ret;
828 enum lttng_error_code ret_code = LTTNG_OK;
829
830 assert(uri);
831
832 if (consumer == NULL) {
833 DBG("No consumer detected. Don't add URI. Stopping.");
834 ret_code = LTTNG_ERR_NO_CONSUMER;
835 goto error;
836 }
837
838 switch (domain) {
839 case LTTNG_DOMAIN_KERNEL:
840 ret = lttng_strncpy(consumer->domain_subdir,
841 DEFAULT_KERNEL_TRACE_DIR,
842 sizeof(consumer->domain_subdir));
843 break;
844 case LTTNG_DOMAIN_UST:
845 ret = lttng_strncpy(consumer->domain_subdir,
846 DEFAULT_UST_TRACE_DIR,
847 sizeof(consumer->domain_subdir));
848 break;
849 default:
850 /*
851 * This case is possible is we try to add the URI to the global
852 * tracing session consumer object which in this case there is
853 * no subdir.
854 */
855 memset(consumer->domain_subdir, 0,
856 sizeof(consumer->domain_subdir));
857 ret = 0;
858 }
859 if (ret) {
860 ERR("Failed to initialize consumer output domain subdirectory");
861 ret_code = LTTNG_ERR_FATAL;
862 goto error;
863 }
864
865 switch (uri->dtype) {
866 case LTTNG_DST_IPV4:
867 case LTTNG_DST_IPV6:
868 DBG2("Setting network URI to consumer");
869
870 if (consumer->type == CONSUMER_DST_NET) {
871 if ((uri->stype == LTTNG_STREAM_CONTROL &&
872 consumer->dst.net.control_isset) ||
873 (uri->stype == LTTNG_STREAM_DATA &&
874 consumer->dst.net.data_isset)) {
875 ret_code = LTTNG_ERR_URL_EXIST;
876 goto error;
877 }
878 } else {
879 memset(&consumer->dst, 0, sizeof(consumer->dst));
880 }
881
882 /* Set URI into consumer output object */
883 ret = consumer_set_network_uri(session, consumer, uri);
884 if (ret < 0) {
885 ret_code = -ret;
886 goto error;
887 } else if (ret == 1) {
888 /*
889 * URI was the same in the consumer so we do not append the subdir
890 * again so to not duplicate output dir.
891 */
892 ret_code = LTTNG_OK;
893 goto error;
894 }
895 break;
896 case LTTNG_DST_PATH:
897 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
898 ret_code = LTTNG_ERR_INVALID;
899 goto error;
900 }
901 DBG2("Setting trace directory path from URI to %s",
902 uri->dst.path);
903 memset(&consumer->dst, 0, sizeof(consumer->dst));
904
905 ret = lttng_strncpy(consumer->dst.session_root_path,
906 uri->dst.path,
907 sizeof(consumer->dst.session_root_path));
908 if (ret) {
909 ret_code = LTTNG_ERR_FATAL;
910 goto error;
911 }
912 consumer->type = CONSUMER_DST_LOCAL;
913 break;
914 }
915
916 ret_code = LTTNG_OK;
917 error:
918 return ret_code;
919 }
920
921 /*
922 * Init tracing by creating trace directory and sending fds kernel consumer.
923 */
924 static int init_kernel_tracing(struct ltt_kernel_session *session)
925 {
926 int ret = 0;
927 struct lttng_ht_iter iter;
928 struct consumer_socket *socket;
929
930 assert(session);
931
932 rcu_read_lock();
933
934 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
935 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
936 socket, node.node) {
937 pthread_mutex_lock(socket->lock);
938 ret = kernel_consumer_send_session(socket, session);
939 pthread_mutex_unlock(socket->lock);
940 if (ret < 0) {
941 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
942 goto error;
943 }
944 }
945 }
946
947 error:
948 rcu_read_unlock();
949 return ret;
950 }
951
952 /*
953 * Create a socket to the relayd using the URI.
954 *
955 * On success, the relayd_sock pointer is set to the created socket.
956 * Else, it remains untouched and an LTTng error code is returned.
957 */
958 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
959 struct lttcomm_relayd_sock **relayd_sock,
960 struct consumer_output *consumer)
961 {
962 int ret;
963 enum lttng_error_code status = LTTNG_OK;
964 struct lttcomm_relayd_sock *rsock;
965
966 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
967 RELAYD_VERSION_COMM_MINOR);
968 if (!rsock) {
969 status = LTTNG_ERR_FATAL;
970 goto error;
971 }
972
973 /*
974 * Connect to relayd so we can proceed with a session creation. This call
975 * can possibly block for an arbitrary amount of time to set the health
976 * state to be in poll execution.
977 */
978 health_poll_entry();
979 ret = relayd_connect(rsock);
980 health_poll_exit();
981 if (ret < 0) {
982 ERR("Unable to reach lttng-relayd");
983 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
984 goto free_sock;
985 }
986
987 /* Create socket for control stream. */
988 if (uri->stype == LTTNG_STREAM_CONTROL) {
989 uint64_t result_flags;
990
991 DBG3("Creating relayd stream socket from URI");
992
993 /* Check relayd version */
994 ret = relayd_version_check(rsock);
995 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
996 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
997 goto close_sock;
998 } else if (ret < 0) {
999 ERR("Unable to reach lttng-relayd");
1000 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1001 goto close_sock;
1002 }
1003 consumer->relay_major_version = rsock->major;
1004 consumer->relay_minor_version = rsock->minor;
1005 ret = relayd_get_configuration(rsock, 0,
1006 &result_flags);
1007 if (ret < 0) {
1008 ERR("Unable to get relayd configuration");
1009 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1010 goto close_sock;
1011 }
1012 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
1013 consumer->relay_allows_clear = true;
1014 }
1015 } else if (uri->stype == LTTNG_STREAM_DATA) {
1016 DBG3("Creating relayd data socket from URI");
1017 } else {
1018 /* Command is not valid */
1019 ERR("Relayd invalid stream type: %d", uri->stype);
1020 status = LTTNG_ERR_INVALID;
1021 goto close_sock;
1022 }
1023
1024 *relayd_sock = rsock;
1025
1026 return status;
1027
1028 close_sock:
1029 /* The returned value is not useful since we are on an error path. */
1030 (void) relayd_close(rsock);
1031 free_sock:
1032 free(rsock);
1033 error:
1034 return status;
1035 }
1036
1037 /*
1038 * Connect to the relayd using URI and send the socket to the right consumer.
1039 *
1040 * The consumer socket lock must be held by the caller.
1041 *
1042 * Returns LTTNG_OK on success or an LTTng error code on failure.
1043 */
1044 static enum lttng_error_code send_consumer_relayd_socket(
1045 unsigned int session_id,
1046 struct lttng_uri *relayd_uri,
1047 struct consumer_output *consumer,
1048 struct consumer_socket *consumer_sock,
1049 const char *session_name, const char *hostname,
1050 const char *base_path, int session_live_timer,
1051 const uint64_t *current_chunk_id,
1052 time_t session_creation_time,
1053 bool session_name_contains_creation_time)
1054 {
1055 int ret;
1056 struct lttcomm_relayd_sock *rsock = NULL;
1057 enum lttng_error_code status;
1058
1059 /* Connect to relayd and make version check if uri is the control. */
1060 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1061 if (status != LTTNG_OK) {
1062 goto relayd_comm_error;
1063 }
1064 assert(rsock);
1065
1066 /* Set the network sequence index if not set. */
1067 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1068 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1069 /*
1070 * Increment net_seq_idx because we are about to transfer the
1071 * new relayd socket to the consumer.
1072 * Assign unique key so the consumer can match streams.
1073 */
1074 consumer->net_seq_index = ++relayd_net_seq_idx;
1075 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1076 }
1077
1078 /* Send relayd socket to consumer. */
1079 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1080 relayd_uri->stype, session_id,
1081 session_name, hostname, base_path,
1082 session_live_timer, current_chunk_id,
1083 session_creation_time, session_name_contains_creation_time);
1084 if (ret < 0) {
1085 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1086 goto close_sock;
1087 }
1088
1089 /* Flag that the corresponding socket was sent. */
1090 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1091 consumer_sock->control_sock_sent = 1;
1092 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1093 consumer_sock->data_sock_sent = 1;
1094 }
1095
1096 /*
1097 * Close socket which was dup on the consumer side. The session daemon does
1098 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1099 */
1100
1101 close_sock:
1102 if (status != LTTNG_OK) {
1103 /*
1104 * The consumer output for this session should not be used anymore
1105 * since the relayd connection failed thus making any tracing or/and
1106 * streaming not usable.
1107 */
1108 consumer->enabled = 0;
1109 }
1110 (void) relayd_close(rsock);
1111 free(rsock);
1112
1113 relayd_comm_error:
1114 return status;
1115 }
1116
1117 /*
1118 * Send both relayd sockets to a specific consumer and domain. This is a
1119 * helper function to facilitate sending the information to the consumer for a
1120 * session.
1121 *
1122 * The consumer socket lock must be held by the caller.
1123 *
1124 * Returns LTTNG_OK, or an LTTng error code on failure.
1125 */
1126 static enum lttng_error_code send_consumer_relayd_sockets(
1127 enum lttng_domain_type domain,
1128 unsigned int session_id, struct consumer_output *consumer,
1129 struct consumer_socket *sock, const char *session_name,
1130 const char *hostname, const char *base_path, int session_live_timer,
1131 const uint64_t *current_chunk_id, time_t session_creation_time,
1132 bool session_name_contains_creation_time)
1133 {
1134 enum lttng_error_code status = LTTNG_OK;
1135
1136 assert(consumer);
1137 assert(sock);
1138
1139 /* Sending control relayd socket. */
1140 if (!sock->control_sock_sent) {
1141 status = send_consumer_relayd_socket(session_id,
1142 &consumer->dst.net.control, consumer, sock,
1143 session_name, hostname, base_path, session_live_timer,
1144 current_chunk_id, session_creation_time,
1145 session_name_contains_creation_time);
1146 if (status != LTTNG_OK) {
1147 goto error;
1148 }
1149 }
1150
1151 /* Sending data relayd socket. */
1152 if (!sock->data_sock_sent) {
1153 status = send_consumer_relayd_socket(session_id,
1154 &consumer->dst.net.data, consumer, sock,
1155 session_name, hostname, base_path, session_live_timer,
1156 current_chunk_id, session_creation_time,
1157 session_name_contains_creation_time);
1158 if (status != LTTNG_OK) {
1159 goto error;
1160 }
1161 }
1162
1163 error:
1164 return status;
1165 }
1166
1167 /*
1168 * Setup relayd connections for a tracing session. First creates the socket to
1169 * the relayd and send them to the right domain consumer. Consumer type MUST be
1170 * network.
1171 */
1172 int cmd_setup_relayd(struct ltt_session *session)
1173 {
1174 int ret = LTTNG_OK;
1175 struct ltt_ust_session *usess;
1176 struct ltt_kernel_session *ksess;
1177 struct consumer_socket *socket;
1178 struct lttng_ht_iter iter;
1179 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1180
1181 assert(session);
1182
1183 usess = session->ust_session;
1184 ksess = session->kernel_session;
1185
1186 DBG("Setting relayd for session %s", session->name);
1187
1188 rcu_read_lock();
1189 if (session->current_trace_chunk) {
1190 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1191 session->current_trace_chunk, &current_chunk_id.value);
1192
1193 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1194 current_chunk_id.is_set = true;
1195 } else {
1196 ERR("Failed to get current trace chunk id");
1197 ret = LTTNG_ERR_UNK;
1198 goto error;
1199 }
1200 }
1201
1202 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1203 && usess->consumer->enabled) {
1204 /* For each consumer socket, send relayd sockets */
1205 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1206 socket, node.node) {
1207 pthread_mutex_lock(socket->lock);
1208 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1209 usess->consumer, socket,
1210 session->name, session->hostname,
1211 session->base_path,
1212 session->live_timer,
1213 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1214 session->creation_time,
1215 session->name_contains_creation_time);
1216 pthread_mutex_unlock(socket->lock);
1217 if (ret != LTTNG_OK) {
1218 goto error;
1219 }
1220 /* Session is now ready for network streaming. */
1221 session->net_handle = 1;
1222 }
1223 session->consumer->relay_major_version =
1224 usess->consumer->relay_major_version;
1225 session->consumer->relay_minor_version =
1226 usess->consumer->relay_minor_version;
1227 session->consumer->relay_allows_clear =
1228 usess->consumer->relay_allows_clear;
1229 }
1230
1231 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1232 && ksess->consumer->enabled) {
1233 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1234 socket, node.node) {
1235 pthread_mutex_lock(socket->lock);
1236 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1237 ksess->consumer, socket,
1238 session->name, session->hostname,
1239 session->base_path,
1240 session->live_timer,
1241 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1242 session->creation_time,
1243 session->name_contains_creation_time);
1244 pthread_mutex_unlock(socket->lock);
1245 if (ret != LTTNG_OK) {
1246 goto error;
1247 }
1248 /* Session is now ready for network streaming. */
1249 session->net_handle = 1;
1250 }
1251 session->consumer->relay_major_version =
1252 ksess->consumer->relay_major_version;
1253 session->consumer->relay_minor_version =
1254 ksess->consumer->relay_minor_version;
1255 session->consumer->relay_allows_clear =
1256 ksess->consumer->relay_allows_clear;
1257 }
1258
1259 error:
1260 rcu_read_unlock();
1261 return ret;
1262 }
1263
1264 /*
1265 * Start a kernel session by opening all necessary streams.
1266 */
1267 int start_kernel_session(struct ltt_kernel_session *ksess)
1268 {
1269 int ret;
1270 struct ltt_kernel_channel *kchan;
1271
1272 /* Open kernel metadata */
1273 if (ksess->metadata == NULL && ksess->output_traces) {
1274 ret = kernel_open_metadata(ksess);
1275 if (ret < 0) {
1276 ret = LTTNG_ERR_KERN_META_FAIL;
1277 goto error;
1278 }
1279 }
1280
1281 /* Open kernel metadata stream */
1282 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1283 ret = kernel_open_metadata_stream(ksess);
1284 if (ret < 0) {
1285 ERR("Kernel create metadata stream failed");
1286 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1287 goto error;
1288 }
1289 }
1290
1291 /* For each channel */
1292 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1293 if (kchan->stream_count == 0) {
1294 ret = kernel_open_channel_stream(kchan);
1295 if (ret < 0) {
1296 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1297 goto error;
1298 }
1299 /* Update the stream global counter */
1300 ksess->stream_count_global += ret;
1301 }
1302 }
1303
1304 /* Setup kernel consumer socket and send fds to it */
1305 ret = init_kernel_tracing(ksess);
1306 if (ret != 0) {
1307 ret = LTTNG_ERR_KERN_START_FAIL;
1308 goto error;
1309 }
1310
1311 /* This start the kernel tracing */
1312 ret = kernel_start_session(ksess);
1313 if (ret < 0) {
1314 ret = LTTNG_ERR_KERN_START_FAIL;
1315 goto error;
1316 }
1317
1318 /* Quiescent wait after starting trace */
1319 kernel_wait_quiescent();
1320
1321 ksess->active = 1;
1322
1323 ret = LTTNG_OK;
1324
1325 error:
1326 return ret;
1327 }
1328
1329 int stop_kernel_session(struct ltt_kernel_session *ksess)
1330 {
1331 struct ltt_kernel_channel *kchan;
1332 bool error_occurred = false;
1333 int ret;
1334
1335 if (!ksess || !ksess->active) {
1336 return LTTNG_OK;
1337 }
1338 DBG("Stopping kernel tracing");
1339
1340 ret = kernel_stop_session(ksess);
1341 if (ret < 0) {
1342 ret = LTTNG_ERR_KERN_STOP_FAIL;
1343 goto error;
1344 }
1345
1346 kernel_wait_quiescent();
1347
1348 /* Flush metadata after stopping (if exists) */
1349 if (ksess->metadata_stream_fd >= 0) {
1350 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1351 if (ret < 0) {
1352 ERR("Kernel metadata flush failed");
1353 error_occurred = true;
1354 }
1355 }
1356
1357 /* Flush all buffers after stopping */
1358 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1359 ret = kernel_flush_buffer(kchan);
1360 if (ret < 0) {
1361 ERR("Kernel flush buffer error");
1362 error_occurred = true;
1363 }
1364 }
1365
1366 ksess->active = 0;
1367 if (error_occurred) {
1368 ret = LTTNG_ERR_UNK;
1369 } else {
1370 ret = LTTNG_OK;
1371 }
1372 error:
1373 return ret;
1374 }
1375
1376 /*
1377 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1378 */
1379 int cmd_disable_channel(struct ltt_session *session,
1380 enum lttng_domain_type domain, char *channel_name)
1381 {
1382 int ret;
1383 struct ltt_ust_session *usess;
1384
1385 usess = session->ust_session;
1386
1387 rcu_read_lock();
1388
1389 switch (domain) {
1390 case LTTNG_DOMAIN_KERNEL:
1391 {
1392 ret = channel_kernel_disable(session->kernel_session,
1393 channel_name);
1394 if (ret != LTTNG_OK) {
1395 goto error;
1396 }
1397
1398 kernel_wait_quiescent();
1399 break;
1400 }
1401 case LTTNG_DOMAIN_UST:
1402 {
1403 struct ltt_ust_channel *uchan;
1404 struct lttng_ht *chan_ht;
1405
1406 chan_ht = usess->domain_global.channels;
1407
1408 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1409 if (uchan == NULL) {
1410 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1411 goto error;
1412 }
1413
1414 ret = channel_ust_disable(usess, uchan);
1415 if (ret != LTTNG_OK) {
1416 goto error;
1417 }
1418 break;
1419 }
1420 default:
1421 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1422 goto error;
1423 }
1424
1425 ret = LTTNG_OK;
1426
1427 error:
1428 rcu_read_unlock();
1429 return ret;
1430 }
1431
1432 /*
1433 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1434 *
1435 * The wpipe arguments is used as a notifier for the kernel thread.
1436 */
1437 int cmd_enable_channel(struct ltt_session *session,
1438 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1439 {
1440 int ret;
1441 struct ltt_ust_session *usess = session->ust_session;
1442 struct lttng_ht *chan_ht;
1443 size_t len;
1444 struct lttng_channel attr;
1445
1446 assert(session);
1447 assert(_attr);
1448 assert(domain);
1449
1450 attr = *_attr;
1451 len = lttng_strnlen(attr.name, sizeof(attr.name));
1452
1453 /* Validate channel name */
1454 if (attr.name[0] == '.' ||
1455 memchr(attr.name, '/', len) != NULL) {
1456 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1457 goto end;
1458 }
1459
1460 DBG("Enabling channel %s for session %s", attr.name, session->name);
1461
1462 rcu_read_lock();
1463
1464 /*
1465 * Don't try to enable a channel if the session has been started at
1466 * some point in time before. The tracer does not allow it.
1467 */
1468 if (session->has_been_started) {
1469 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1470 goto error;
1471 }
1472
1473 /*
1474 * If the session is a live session, remove the switch timer, the
1475 * live timer does the same thing but sends also synchronisation
1476 * beacons for inactive streams.
1477 */
1478 if (session->live_timer > 0) {
1479 attr.attr.live_timer_interval = session->live_timer;
1480 attr.attr.switch_timer_interval = 0;
1481 }
1482
1483 /* Check for feature support */
1484 switch (domain->type) {
1485 case LTTNG_DOMAIN_KERNEL:
1486 {
1487 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1488 /* Sampling position of buffer is not supported */
1489 WARN("Kernel tracer does not support buffer monitoring. "
1490 "Setting the monitor interval timer to 0 "
1491 "(disabled) for channel '%s' of session '%s'",
1492 attr.name, session->name);
1493 lttng_channel_set_monitor_timer_interval(&attr, 0);
1494 }
1495 break;
1496 }
1497 case LTTNG_DOMAIN_UST:
1498 break;
1499 case LTTNG_DOMAIN_JUL:
1500 case LTTNG_DOMAIN_LOG4J:
1501 case LTTNG_DOMAIN_PYTHON:
1502 if (!agent_tracing_is_enabled()) {
1503 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1504 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1505 goto error;
1506 }
1507 break;
1508 default:
1509 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1510 goto error;
1511 }
1512
1513 switch (domain->type) {
1514 case LTTNG_DOMAIN_KERNEL:
1515 {
1516 struct ltt_kernel_channel *kchan;
1517
1518 kchan = trace_kernel_get_channel_by_name(attr.name,
1519 session->kernel_session);
1520 if (kchan == NULL) {
1521 if (session->snapshot.nb_output > 0 ||
1522 session->snapshot_mode) {
1523 /* Enforce mmap output for snapshot sessions. */
1524 attr.attr.output = LTTNG_EVENT_MMAP;
1525 }
1526 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1527 if (attr.name[0] != '\0') {
1528 session->kernel_session->has_non_default_channel = 1;
1529 }
1530 } else {
1531 ret = channel_kernel_enable(session->kernel_session, kchan);
1532 }
1533
1534 if (ret != LTTNG_OK) {
1535 goto error;
1536 }
1537
1538 kernel_wait_quiescent();
1539 break;
1540 }
1541 case LTTNG_DOMAIN_UST:
1542 case LTTNG_DOMAIN_JUL:
1543 case LTTNG_DOMAIN_LOG4J:
1544 case LTTNG_DOMAIN_PYTHON:
1545 {
1546 struct ltt_ust_channel *uchan;
1547
1548 /*
1549 * FIXME
1550 *
1551 * Current agent implementation limitations force us to allow
1552 * only one channel at once in "agent" subdomains. Each
1553 * subdomain has a default channel name which must be strictly
1554 * adhered to.
1555 */
1556 if (domain->type == LTTNG_DOMAIN_JUL) {
1557 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1558 LTTNG_SYMBOL_NAME_LEN)) {
1559 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1560 goto error;
1561 }
1562 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1563 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1564 LTTNG_SYMBOL_NAME_LEN)) {
1565 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1566 goto error;
1567 }
1568 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1569 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1570 LTTNG_SYMBOL_NAME_LEN)) {
1571 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1572 goto error;
1573 }
1574 }
1575
1576 chan_ht = usess->domain_global.channels;
1577
1578 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1579 if (uchan == NULL) {
1580 ret = channel_ust_create(usess, &attr, domain->buf_type);
1581 if (attr.name[0] != '\0') {
1582 usess->has_non_default_channel = 1;
1583 }
1584 } else {
1585 ret = channel_ust_enable(usess, uchan);
1586 }
1587 break;
1588 }
1589 default:
1590 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1591 goto error;
1592 }
1593
1594 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1595 session->has_non_mmap_channel = true;
1596 }
1597 error:
1598 rcu_read_unlock();
1599 end:
1600 return ret;
1601 }
1602
1603 enum lttng_error_code cmd_process_attr_tracker_get_tracking_policy(
1604 struct ltt_session *session,
1605 enum lttng_domain_type domain,
1606 enum lttng_process_attr process_attr,
1607 enum lttng_tracking_policy *policy)
1608 {
1609 enum lttng_error_code ret_code = LTTNG_OK;
1610 const struct process_attr_tracker *tracker;
1611
1612 switch (domain) {
1613 case LTTNG_DOMAIN_KERNEL:
1614 if (!session->kernel_session) {
1615 ret_code = LTTNG_ERR_INVALID;
1616 goto end;
1617 }
1618 tracker = kernel_get_process_attr_tracker(
1619 session->kernel_session, process_attr);
1620 break;
1621 case LTTNG_DOMAIN_UST:
1622 if (!session->ust_session) {
1623 ret_code = LTTNG_ERR_INVALID;
1624 goto end;
1625 }
1626 tracker = trace_ust_get_process_attr_tracker(
1627 session->ust_session, process_attr);
1628 break;
1629 default:
1630 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1631 goto end;
1632 }
1633 if (tracker) {
1634 *policy = process_attr_tracker_get_tracking_policy(tracker);
1635 } else {
1636 ret_code = LTTNG_ERR_INVALID;
1637 }
1638 end:
1639 return ret_code;
1640 }
1641
1642 enum lttng_error_code cmd_process_attr_tracker_set_tracking_policy(
1643 struct ltt_session *session,
1644 enum lttng_domain_type domain,
1645 enum lttng_process_attr process_attr,
1646 enum lttng_tracking_policy policy)
1647 {
1648 enum lttng_error_code ret_code = LTTNG_OK;
1649
1650 switch (policy) {
1651 case LTTNG_TRACKING_POLICY_INCLUDE_SET:
1652 case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
1653 case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
1654 break;
1655 default:
1656 ret_code = LTTNG_ERR_INVALID;
1657 goto end;
1658 }
1659
1660 switch (domain) {
1661 case LTTNG_DOMAIN_KERNEL:
1662 if (!session->kernel_session) {
1663 ret_code = LTTNG_ERR_INVALID;
1664 goto end;
1665 }
1666 ret_code = kernel_process_attr_tracker_set_tracking_policy(
1667 session->kernel_session, process_attr, policy);
1668 break;
1669 case LTTNG_DOMAIN_UST:
1670 if (!session->ust_session) {
1671 ret_code = LTTNG_ERR_INVALID;
1672 goto end;
1673 }
1674 ret_code = trace_ust_process_attr_tracker_set_tracking_policy(
1675 session->ust_session, process_attr, policy);
1676 break;
1677 default:
1678 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1679 break;
1680 }
1681 end:
1682 return ret_code;
1683 }
1684
1685 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_add_value(
1686 struct ltt_session *session,
1687 enum lttng_domain_type domain,
1688 enum lttng_process_attr process_attr,
1689 const struct process_attr_value *value)
1690 {
1691 enum lttng_error_code ret_code = LTTNG_OK;
1692
1693 switch (domain) {
1694 case LTTNG_DOMAIN_KERNEL:
1695 if (!session->kernel_session) {
1696 ret_code = LTTNG_ERR_INVALID;
1697 goto end;
1698 }
1699 ret_code = kernel_process_attr_tracker_inclusion_set_add_value(
1700 session->kernel_session, process_attr, value);
1701 break;
1702 case LTTNG_DOMAIN_UST:
1703 if (!session->ust_session) {
1704 ret_code = LTTNG_ERR_INVALID;
1705 goto end;
1706 }
1707 ret_code = trace_ust_process_attr_tracker_inclusion_set_add_value(
1708 session->ust_session, process_attr, value);
1709 break;
1710 default:
1711 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1712 break;
1713 }
1714 end:
1715 return ret_code;
1716 }
1717
1718 enum lttng_error_code cmd_process_attr_tracker_inclusion_set_remove_value(
1719 struct ltt_session *session,
1720 enum lttng_domain_type domain,
1721 enum lttng_process_attr process_attr,
1722 const struct process_attr_value *value)
1723 {
1724 enum lttng_error_code ret_code = LTTNG_OK;
1725
1726 switch (domain) {
1727 case LTTNG_DOMAIN_KERNEL:
1728 if (!session->kernel_session) {
1729 ret_code = LTTNG_ERR_INVALID;
1730 goto end;
1731 }
1732 ret_code = kernel_process_attr_tracker_inclusion_set_remove_value(
1733 session->kernel_session, process_attr, value);
1734 break;
1735 case LTTNG_DOMAIN_UST:
1736 if (!session->ust_session) {
1737 ret_code = LTTNG_ERR_INVALID;
1738 goto end;
1739 }
1740 ret_code = trace_ust_process_attr_tracker_inclusion_set_remove_value(
1741 session->ust_session, process_attr, value);
1742 break;
1743 default:
1744 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1745 break;
1746 }
1747 end:
1748 return ret_code;
1749 }
1750
1751 enum lttng_error_code cmd_process_attr_tracker_get_inclusion_set(
1752 struct ltt_session *session,
1753 enum lttng_domain_type domain,
1754 enum lttng_process_attr process_attr,
1755 struct lttng_process_attr_values **values)
1756 {
1757 enum lttng_error_code ret_code = LTTNG_OK;
1758 const struct process_attr_tracker *tracker;
1759 enum process_attr_tracker_status status;
1760
1761 switch (domain) {
1762 case LTTNG_DOMAIN_KERNEL:
1763 if (!session->kernel_session) {
1764 ret_code = LTTNG_ERR_INVALID;
1765 goto end;
1766 }
1767 tracker = kernel_get_process_attr_tracker(
1768 session->kernel_session, process_attr);
1769 break;
1770 case LTTNG_DOMAIN_UST:
1771 if (!session->ust_session) {
1772 ret_code = LTTNG_ERR_INVALID;
1773 goto end;
1774 }
1775 tracker = trace_ust_get_process_attr_tracker(
1776 session->ust_session, process_attr);
1777 break;
1778 default:
1779 ret_code = LTTNG_ERR_UNSUPPORTED_DOMAIN;
1780 goto end;
1781 }
1782
1783 if (!tracker) {
1784 ret_code = LTTNG_ERR_INVALID;
1785 goto end;
1786 }
1787
1788 status = process_attr_tracker_get_inclusion_set(tracker, values);
1789 switch (status) {
1790 case PROCESS_ATTR_TRACKER_STATUS_OK:
1791 ret_code = LTTNG_OK;
1792 break;
1793 case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
1794 ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
1795 break;
1796 case PROCESS_ATTR_TRACKER_STATUS_ERROR:
1797 ret_code = LTTNG_ERR_NOMEM;
1798 break;
1799 default:
1800 ret_code = LTTNG_ERR_UNK;
1801 break;
1802 }
1803
1804 end:
1805 return ret_code;
1806 }
1807
1808 /*
1809 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1810 */
1811 int cmd_disable_event(struct ltt_session *session,
1812 enum lttng_domain_type domain, const char *channel_name,
1813 const struct lttng_event *event)
1814 {
1815 int ret;
1816 const char *event_name;
1817
1818 DBG("Disable event command for event \'%s\'", event->name);
1819
1820 event_name = event->name;
1821
1822 /* Error out on unhandled search criteria */
1823 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1824 || event->pid || event->filter || event->exclusion) {
1825 ret = LTTNG_ERR_UNK;
1826 goto error;
1827 }
1828
1829 rcu_read_lock();
1830
1831 switch (domain) {
1832 case LTTNG_DOMAIN_KERNEL:
1833 {
1834 struct ltt_kernel_channel *kchan;
1835 struct ltt_kernel_session *ksess;
1836
1837 ksess = session->kernel_session;
1838
1839 /*
1840 * If a non-default channel has been created in the
1841 * session, explicitely require that -c chan_name needs
1842 * to be provided.
1843 */
1844 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1845 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1846 goto error_unlock;
1847 }
1848
1849 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1850 if (kchan == NULL) {
1851 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1852 goto error_unlock;
1853 }
1854
1855 switch (event->type) {
1856 case LTTNG_EVENT_ALL:
1857 case LTTNG_EVENT_TRACEPOINT:
1858 case LTTNG_EVENT_SYSCALL:
1859 case LTTNG_EVENT_PROBE:
1860 case LTTNG_EVENT_FUNCTION:
1861 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1862 if (event_name[0] == '\0') {
1863 ret = event_kernel_disable_event(kchan,
1864 NULL, event->type);
1865 } else {
1866 ret = event_kernel_disable_event(kchan,
1867 event_name, event->type);
1868 }
1869 if (ret != LTTNG_OK) {
1870 goto error_unlock;
1871 }
1872 break;
1873 default:
1874 ret = LTTNG_ERR_UNK;
1875 goto error_unlock;
1876 }
1877
1878 kernel_wait_quiescent();
1879 break;
1880 }
1881 case LTTNG_DOMAIN_UST:
1882 {
1883 struct ltt_ust_channel *uchan;
1884 struct ltt_ust_session *usess;
1885
1886 usess = session->ust_session;
1887
1888 if (validate_ust_event_name(event_name)) {
1889 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1890 goto error_unlock;
1891 }
1892
1893 /*
1894 * If a non-default channel has been created in the
1895 * session, explicitly require that -c chan_name needs
1896 * to be provided.
1897 */
1898 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1899 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1900 goto error_unlock;
1901 }
1902
1903 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1904 channel_name);
1905 if (uchan == NULL) {
1906 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1907 goto error_unlock;
1908 }
1909
1910 switch (event->type) {
1911 case LTTNG_EVENT_ALL:
1912 /*
1913 * An empty event name means that everything
1914 * should be disabled.
1915 */
1916 if (event->name[0] == '\0') {
1917 ret = event_ust_disable_all_tracepoints(usess, uchan);
1918 } else {
1919 ret = event_ust_disable_tracepoint(usess, uchan,
1920 event_name);
1921 }
1922 if (ret != LTTNG_OK) {
1923 goto error_unlock;
1924 }
1925 break;
1926 default:
1927 ret = LTTNG_ERR_UNK;
1928 goto error_unlock;
1929 }
1930
1931 DBG3("Disable UST event %s in channel %s completed", event_name,
1932 channel_name);
1933 break;
1934 }
1935 case LTTNG_DOMAIN_LOG4J:
1936 case LTTNG_DOMAIN_JUL:
1937 case LTTNG_DOMAIN_PYTHON:
1938 {
1939 struct agent *agt;
1940 struct ltt_ust_session *usess = session->ust_session;
1941
1942 assert(usess);
1943
1944 switch (event->type) {
1945 case LTTNG_EVENT_ALL:
1946 break;
1947 default:
1948 ret = LTTNG_ERR_UNK;
1949 goto error_unlock;
1950 }
1951
1952 agt = trace_ust_find_agent(usess, domain);
1953 if (!agt) {
1954 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1955 goto error_unlock;
1956 }
1957 /*
1958 * An empty event name means that everything
1959 * should be disabled.
1960 */
1961 if (event->name[0] == '\0') {
1962 ret = event_agent_disable_all(usess, agt);
1963 } else {
1964 ret = event_agent_disable(usess, agt, event_name);
1965 }
1966 if (ret != LTTNG_OK) {
1967 goto error_unlock;
1968 }
1969
1970 break;
1971 }
1972 default:
1973 ret = LTTNG_ERR_UND;
1974 goto error_unlock;
1975 }
1976
1977 ret = LTTNG_OK;
1978
1979 error_unlock:
1980 rcu_read_unlock();
1981 error:
1982 return ret;
1983 }
1984
1985 /*
1986 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1987 */
1988 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1989 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1990 {
1991 int ret, chan_kern_created = 0, chan_ust_created = 0;
1992 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1993
1994 /*
1995 * Don't try to add a context if the session has been started at
1996 * some point in time before. The tracer does not allow it and would
1997 * result in a corrupted trace.
1998 */
1999 if (session->has_been_started) {
2000 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2001 goto end;
2002 }
2003
2004 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
2005 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
2006 app_ctx_name = ctx->u.app_ctx.ctx_name;
2007 }
2008
2009 switch (domain) {
2010 case LTTNG_DOMAIN_KERNEL:
2011 assert(session->kernel_session);
2012
2013 if (session->kernel_session->channel_count == 0) {
2014 /* Create default channel */
2015 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
2016 if (ret != LTTNG_OK) {
2017 goto error;
2018 }
2019 chan_kern_created = 1;
2020 }
2021 /* Add kernel context to kernel tracer */
2022 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
2023 if (ret != LTTNG_OK) {
2024 goto error;
2025 }
2026 break;
2027 case LTTNG_DOMAIN_JUL:
2028 case LTTNG_DOMAIN_LOG4J:
2029 {
2030 /*
2031 * Validate channel name.
2032 * If no channel name is given and the domain is JUL or LOG4J,
2033 * set it to the appropriate domain-specific channel name. If
2034 * a name is provided but does not match the expexted channel
2035 * name, return an error.
2036 */
2037 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
2038 strcmp(channel_name,
2039 DEFAULT_JUL_CHANNEL_NAME)) {
2040 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2041 goto error;
2042 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
2043 strcmp(channel_name,
2044 DEFAULT_LOG4J_CHANNEL_NAME)) {
2045 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2046 goto error;
2047 }
2048 /* break is _not_ missing here. */
2049 }
2050 case LTTNG_DOMAIN_UST:
2051 {
2052 struct ltt_ust_session *usess = session->ust_session;
2053 unsigned int chan_count;
2054
2055 assert(usess);
2056
2057 chan_count = lttng_ht_get_count(usess->domain_global.channels);
2058 if (chan_count == 0) {
2059 struct lttng_channel *attr;
2060 /* Create default channel */
2061 attr = channel_new_default_attr(domain, usess->buffer_type);
2062 if (attr == NULL) {
2063 ret = LTTNG_ERR_FATAL;
2064 goto error;
2065 }
2066
2067 ret = channel_ust_create(usess, attr, usess->buffer_type);
2068 if (ret != LTTNG_OK) {
2069 free(attr);
2070 goto error;
2071 }
2072 channel_attr_destroy(attr);
2073 chan_ust_created = 1;
2074 }
2075
2076 ret = context_ust_add(usess, domain, ctx, channel_name);
2077 free(app_ctx_provider_name);
2078 free(app_ctx_name);
2079 app_ctx_name = NULL;
2080 app_ctx_provider_name = NULL;
2081 if (ret != LTTNG_OK) {
2082 goto error;
2083 }
2084 break;
2085 }
2086 default:
2087 ret = LTTNG_ERR_UND;
2088 goto error;
2089 }
2090
2091 ret = LTTNG_OK;
2092 goto end;
2093
2094 error:
2095 if (chan_kern_created) {
2096 struct ltt_kernel_channel *kchan =
2097 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
2098 session->kernel_session);
2099 /* Created previously, this should NOT fail. */
2100 assert(kchan);
2101 kernel_destroy_channel(kchan);
2102 }
2103
2104 if (chan_ust_created) {
2105 struct ltt_ust_channel *uchan =
2106 trace_ust_find_channel_by_name(
2107 session->ust_session->domain_global.channels,
2108 DEFAULT_CHANNEL_NAME);
2109 /* Created previously, this should NOT fail. */
2110 assert(uchan);
2111 /* Remove from the channel list of the session. */
2112 trace_ust_delete_channel(session->ust_session->domain_global.channels,
2113 uchan);
2114 trace_ust_destroy_channel(uchan);
2115 }
2116 end:
2117 free(app_ctx_provider_name);
2118 free(app_ctx_name);
2119 return ret;
2120 }
2121
2122 static inline bool name_starts_with(const char *name, const char *prefix)
2123 {
2124 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
2125
2126 return !strncmp(name, prefix, max_cmp_len);
2127 }
2128
2129 /* Perform userspace-specific event name validation */
2130 static int validate_ust_event_name(const char *name)
2131 {
2132 int ret = 0;
2133
2134 if (!name) {
2135 ret = -1;
2136 goto end;
2137 }
2138
2139 /*
2140 * Check name against all internal UST event component namespaces used
2141 * by the agents.
2142 */
2143 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2144 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2145 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2146 ret = -1;
2147 }
2148
2149 end:
2150 return ret;
2151 }
2152
2153 /*
2154 * Internal version of cmd_enable_event() with a supplemental
2155 * "internal_event" flag which is used to enable internal events which should
2156 * be hidden from clients. Such events are used in the agent implementation to
2157 * enable the events through which all "agent" events are funeled.
2158 */
2159 static int _cmd_enable_event(struct ltt_session *session,
2160 const struct lttng_domain *domain,
2161 char *channel_name, struct lttng_event *event,
2162 char *filter_expression,
2163 struct lttng_filter_bytecode *filter,
2164 struct lttng_event_exclusion *exclusion,
2165 int wpipe, bool internal_event)
2166 {
2167 int ret = 0, channel_created = 0;
2168 struct lttng_channel *attr = NULL;
2169
2170 assert(session);
2171 assert(event);
2172 assert(channel_name);
2173
2174 /* If we have a filter, we must have its filter expression */
2175 assert(!(!!filter_expression ^ !!filter));
2176
2177 /* Normalize event name as a globbing pattern */
2178 strutils_normalize_star_glob_pattern(event->name);
2179
2180 /* Normalize exclusion names as globbing patterns */
2181 if (exclusion) {
2182 size_t i;
2183
2184 for (i = 0; i < exclusion->count; i++) {
2185 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2186
2187 strutils_normalize_star_glob_pattern(name);
2188 }
2189 }
2190
2191 DBG("Enable event command for event \'%s\'", event->name);
2192
2193 rcu_read_lock();
2194
2195 switch (domain->type) {
2196 case LTTNG_DOMAIN_KERNEL:
2197 {
2198 struct ltt_kernel_channel *kchan;
2199
2200 /*
2201 * If a non-default channel has been created in the
2202 * session, explicitely require that -c chan_name needs
2203 * to be provided.
2204 */
2205 if (session->kernel_session->has_non_default_channel
2206 && channel_name[0] == '\0') {
2207 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2208 goto error;
2209 }
2210
2211 kchan = trace_kernel_get_channel_by_name(channel_name,
2212 session->kernel_session);
2213 if (kchan == NULL) {
2214 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2215 LTTNG_BUFFER_GLOBAL);
2216 if (attr == NULL) {
2217 ret = LTTNG_ERR_FATAL;
2218 goto error;
2219 }
2220 if (lttng_strncpy(attr->name, channel_name,
2221 sizeof(attr->name))) {
2222 ret = LTTNG_ERR_INVALID;
2223 goto error;
2224 }
2225
2226 ret = cmd_enable_channel(session, domain, attr, wpipe);
2227 if (ret != LTTNG_OK) {
2228 goto error;
2229 }
2230 channel_created = 1;
2231 }
2232
2233 /* Get the newly created kernel channel pointer */
2234 kchan = trace_kernel_get_channel_by_name(channel_name,
2235 session->kernel_session);
2236 if (kchan == NULL) {
2237 /* This sould not happen... */
2238 ret = LTTNG_ERR_FATAL;
2239 goto error;
2240 }
2241
2242 switch (event->type) {
2243 case LTTNG_EVENT_ALL:
2244 {
2245 char *filter_expression_a = NULL;
2246 struct lttng_filter_bytecode *filter_a = NULL;
2247
2248 /*
2249 * We need to duplicate filter_expression and filter,
2250 * because ownership is passed to first enable
2251 * event.
2252 */
2253 if (filter_expression) {
2254 filter_expression_a = strdup(filter_expression);
2255 if (!filter_expression_a) {
2256 ret = LTTNG_ERR_FATAL;
2257 goto error;
2258 }
2259 }
2260 if (filter) {
2261 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2262 if (!filter_a) {
2263 free(filter_expression_a);
2264 ret = LTTNG_ERR_FATAL;
2265 goto error;
2266 }
2267 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2268 }
2269 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2270 ret = event_kernel_enable_event(kchan, event,
2271 filter_expression, filter);
2272 /* We have passed ownership */
2273 filter_expression = NULL;
2274 filter = NULL;
2275 if (ret != LTTNG_OK) {
2276 if (channel_created) {
2277 /* Let's not leak a useless channel. */
2278 kernel_destroy_channel(kchan);
2279 }
2280 free(filter_expression_a);
2281 free(filter_a);
2282 goto error;
2283 }
2284 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2285 ret = event_kernel_enable_event(kchan, event,
2286 filter_expression_a, filter_a);
2287 /* We have passed ownership */
2288 filter_expression_a = NULL;
2289 filter_a = NULL;
2290 if (ret != LTTNG_OK) {
2291 goto error;
2292 }
2293 break;
2294 }
2295 case LTTNG_EVENT_PROBE:
2296 case LTTNG_EVENT_USERSPACE_PROBE:
2297 case LTTNG_EVENT_FUNCTION:
2298 case LTTNG_EVENT_FUNCTION_ENTRY:
2299 case LTTNG_EVENT_TRACEPOINT:
2300 ret = event_kernel_enable_event(kchan, event,
2301 filter_expression, filter);
2302 /* We have passed ownership */
2303 filter_expression = NULL;
2304 filter = NULL;
2305 if (ret != LTTNG_OK) {
2306 if (channel_created) {
2307 /* Let's not leak a useless channel. */
2308 kernel_destroy_channel(kchan);
2309 }
2310 goto error;
2311 }
2312 break;
2313 case LTTNG_EVENT_SYSCALL:
2314 ret = event_kernel_enable_event(kchan, event,
2315 filter_expression, filter);
2316 /* We have passed ownership */
2317 filter_expression = NULL;
2318 filter = NULL;
2319 if (ret != LTTNG_OK) {
2320 goto error;
2321 }
2322 break;
2323 default:
2324 ret = LTTNG_ERR_UNK;
2325 goto error;
2326 }
2327
2328 kernel_wait_quiescent();
2329 break;
2330 }
2331 case LTTNG_DOMAIN_UST:
2332 {
2333 struct ltt_ust_channel *uchan;
2334 struct ltt_ust_session *usess = session->ust_session;
2335
2336 assert(usess);
2337
2338 /*
2339 * If a non-default channel has been created in the
2340 * session, explicitely require that -c chan_name needs
2341 * to be provided.
2342 */
2343 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2344 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2345 goto error;
2346 }
2347
2348 /* Get channel from global UST domain */
2349 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2350 channel_name);
2351 if (uchan == NULL) {
2352 /* Create default channel */
2353 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2354 usess->buffer_type);
2355 if (attr == NULL) {
2356 ret = LTTNG_ERR_FATAL;
2357 goto error;
2358 }
2359 if (lttng_strncpy(attr->name, channel_name,
2360 sizeof(attr->name))) {
2361 ret = LTTNG_ERR_INVALID;
2362 goto error;
2363 }
2364
2365 ret = cmd_enable_channel(session, domain, attr, wpipe);
2366 if (ret != LTTNG_OK) {
2367 goto error;
2368 }
2369
2370 /* Get the newly created channel reference back */
2371 uchan = trace_ust_find_channel_by_name(
2372 usess->domain_global.channels, channel_name);
2373 assert(uchan);
2374 }
2375
2376 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2377 /*
2378 * Don't allow users to add UST events to channels which
2379 * are assigned to a userspace subdomain (JUL, Log4J,
2380 * Python, etc.).
2381 */
2382 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2383 goto error;
2384 }
2385
2386 if (!internal_event) {
2387 /*
2388 * Ensure the event name is not reserved for internal
2389 * use.
2390 */
2391 ret = validate_ust_event_name(event->name);
2392 if (ret) {
2393 WARN("Userspace event name %s failed validation.",
2394 event->name);
2395 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2396 goto error;
2397 }
2398 }
2399
2400 /* At this point, the session and channel exist on the tracer */
2401 ret = event_ust_enable_tracepoint(usess, uchan, event,
2402 filter_expression, filter, exclusion,
2403 internal_event);
2404 /* We have passed ownership */
2405 filter_expression = NULL;
2406 filter = NULL;
2407 exclusion = NULL;
2408 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2409 goto already_enabled;
2410 } else if (ret != LTTNG_OK) {
2411 goto error;
2412 }
2413 break;
2414 }
2415 case LTTNG_DOMAIN_LOG4J:
2416 case LTTNG_DOMAIN_JUL:
2417 case LTTNG_DOMAIN_PYTHON:
2418 {
2419 const char *default_event_name, *default_chan_name;
2420 struct agent *agt;
2421 struct lttng_event uevent;
2422 struct lttng_domain tmp_dom;
2423 struct ltt_ust_session *usess = session->ust_session;
2424
2425 assert(usess);
2426
2427 if (!agent_tracing_is_enabled()) {
2428 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2429 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2430 goto error;
2431 }
2432
2433 agt = trace_ust_find_agent(usess, domain->type);
2434 if (!agt) {
2435 agt = agent_create(domain->type);
2436 if (!agt) {
2437 ret = LTTNG_ERR_NOMEM;
2438 goto error;
2439 }
2440 agent_add(agt, usess->agents);
2441 }
2442
2443 /* Create the default tracepoint. */
2444 memset(&uevent, 0, sizeof(uevent));
2445 uevent.type = LTTNG_EVENT_TRACEPOINT;
2446 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2447 default_event_name = event_get_default_agent_ust_name(
2448 domain->type);
2449 if (!default_event_name) {
2450 ret = LTTNG_ERR_FATAL;
2451 goto error;
2452 }
2453 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2454 uevent.name[sizeof(uevent.name) - 1] = '\0';
2455
2456 /*
2457 * The domain type is changed because we are about to enable the
2458 * default channel and event for the JUL domain that are hardcoded.
2459 * This happens in the UST domain.
2460 */
2461 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2462 tmp_dom.type = LTTNG_DOMAIN_UST;
2463
2464 switch (domain->type) {
2465 case LTTNG_DOMAIN_LOG4J:
2466 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2467 break;
2468 case LTTNG_DOMAIN_JUL:
2469 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2470 break;
2471 case LTTNG_DOMAIN_PYTHON:
2472 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2473 break;
2474 default:
2475 /* The switch/case we are in makes this impossible */
2476 assert(0);
2477 }
2478
2479 {
2480 char *filter_expression_copy = NULL;
2481 struct lttng_filter_bytecode *filter_copy = NULL;
2482
2483 if (filter) {
2484 const size_t filter_size = sizeof(
2485 struct lttng_filter_bytecode)
2486 + filter->len;
2487
2488 filter_copy = zmalloc(filter_size);
2489 if (!filter_copy) {
2490 ret = LTTNG_ERR_NOMEM;
2491 goto error;
2492 }
2493 memcpy(filter_copy, filter, filter_size);
2494
2495 filter_expression_copy =
2496 strdup(filter_expression);
2497 if (!filter_expression) {
2498 ret = LTTNG_ERR_NOMEM;
2499 }
2500
2501 if (!filter_expression_copy || !filter_copy) {
2502 free(filter_expression_copy);
2503 free(filter_copy);
2504 goto error;
2505 }
2506 }
2507
2508 ret = cmd_enable_event_internal(session, &tmp_dom,
2509 (char *) default_chan_name,
2510 &uevent, filter_expression_copy,
2511 filter_copy, NULL, wpipe);
2512 }
2513
2514 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2515 goto already_enabled;
2516 } else if (ret != LTTNG_OK) {
2517 goto error;
2518 }
2519
2520 /* The wild card * means that everything should be enabled. */
2521 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2522 ret = event_agent_enable_all(usess, agt, event, filter,
2523 filter_expression);
2524 } else {
2525 ret = event_agent_enable(usess, agt, event, filter,
2526 filter_expression);
2527 }
2528 filter = NULL;
2529 filter_expression = NULL;
2530 if (ret != LTTNG_OK) {
2531 goto error;
2532 }
2533
2534 break;
2535 }
2536 default:
2537 ret = LTTNG_ERR_UND;
2538 goto error;
2539 }
2540
2541 ret = LTTNG_OK;
2542
2543 already_enabled:
2544 error:
2545 free(filter_expression);
2546 free(filter);
2547 free(exclusion);
2548 channel_attr_destroy(attr);
2549 rcu_read_unlock();
2550 return ret;
2551 }
2552
2553 /*
2554 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2555 * We own filter, exclusion, and filter_expression.
2556 */
2557 int cmd_enable_event(struct ltt_session *session,
2558 const struct lttng_domain *domain,
2559 char *channel_name, struct lttng_event *event,
2560 char *filter_expression,
2561 struct lttng_filter_bytecode *filter,
2562 struct lttng_event_exclusion *exclusion,
2563 int wpipe)
2564 {
2565 return _cmd_enable_event(session, domain, channel_name, event,
2566 filter_expression, filter, exclusion, wpipe, false);
2567 }
2568
2569 /*
2570 * Enable an event which is internal to LTTng. An internal should
2571 * never be made visible to clients and are immune to checks such as
2572 * reserved names.
2573 */
2574 static int cmd_enable_event_internal(struct ltt_session *session,
2575 const struct lttng_domain *domain,
2576 char *channel_name, struct lttng_event *event,
2577 char *filter_expression,
2578 struct lttng_filter_bytecode *filter,
2579 struct lttng_event_exclusion *exclusion,
2580 int wpipe)
2581 {
2582 return _cmd_enable_event(session, domain, channel_name, event,
2583 filter_expression, filter, exclusion, wpipe, true);
2584 }
2585
2586 /*
2587 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2588 */
2589 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2590 struct lttng_event **events)
2591 {
2592 int ret;
2593 ssize_t nb_events = 0;
2594
2595 switch (domain) {
2596 case LTTNG_DOMAIN_KERNEL:
2597 nb_events = kernel_list_events(events);
2598 if (nb_events < 0) {
2599 ret = LTTNG_ERR_KERN_LIST_FAIL;
2600 goto error;
2601 }
2602 break;
2603 case LTTNG_DOMAIN_UST:
2604 nb_events = ust_app_list_events(events);
2605 if (nb_events < 0) {
2606 ret = LTTNG_ERR_UST_LIST_FAIL;
2607 goto error;
2608 }
2609 break;
2610 case LTTNG_DOMAIN_LOG4J:
2611 case LTTNG_DOMAIN_JUL:
2612 case LTTNG_DOMAIN_PYTHON:
2613 nb_events = agent_list_events(events, domain);
2614 if (nb_events < 0) {
2615 ret = LTTNG_ERR_UST_LIST_FAIL;
2616 goto error;
2617 }
2618 break;
2619 default:
2620 ret = LTTNG_ERR_UND;
2621 goto error;
2622 }
2623
2624 return nb_events;
2625
2626 error:
2627 /* Return negative value to differentiate return code */
2628 return -ret;
2629 }
2630
2631 /*
2632 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2633 */
2634 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2635 struct lttng_event_field **fields)
2636 {
2637 int ret;
2638 ssize_t nb_fields = 0;
2639
2640 switch (domain) {
2641 case LTTNG_DOMAIN_UST:
2642 nb_fields = ust_app_list_event_fields(fields);
2643 if (nb_fields < 0) {
2644 ret = LTTNG_ERR_UST_LIST_FAIL;
2645 goto error;
2646 }
2647 break;
2648 case LTTNG_DOMAIN_KERNEL:
2649 default: /* fall-through */
2650 ret = LTTNG_ERR_UND;
2651 goto error;
2652 }
2653
2654 return nb_fields;
2655
2656 error:
2657 /* Return negative value to differentiate return code */
2658 return -ret;
2659 }
2660
2661 ssize_t cmd_list_syscalls(struct lttng_event **events)
2662 {
2663 return syscall_table_list(events);
2664 }
2665
2666 /*
2667 * Command LTTNG_START_TRACE processed by the client thread.
2668 *
2669 * Called with session mutex held.
2670 */
2671 int cmd_start_trace(struct ltt_session *session)
2672 {
2673 enum lttng_error_code ret;
2674 unsigned long nb_chan = 0;
2675 struct ltt_kernel_session *ksession;
2676 struct ltt_ust_session *usess;
2677 const bool session_rotated_after_last_stop =
2678 session->rotated_after_last_stop;
2679 const bool session_cleared_after_last_stop =
2680 session->cleared_after_last_stop;
2681
2682 assert(session);
2683
2684 /* Ease our life a bit ;) */
2685 ksession = session->kernel_session;
2686 usess = session->ust_session;
2687
2688 /* Is the session already started? */
2689 if (session->active) {
2690 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2691 /* Perform nothing */
2692 goto end;
2693 }
2694
2695 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2696 !session->current_trace_chunk) {
2697 /*
2698 * A rotation was launched while the session was stopped and
2699 * it has not been completed yet. It is not possible to start
2700 * the session since starting the session here would require a
2701 * rotation from "NULL" to a new trace chunk. That rotation
2702 * would overlap with the ongoing rotation, which is not
2703 * supported.
2704 */
2705 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2706 session->name);
2707 ret = LTTNG_ERR_ROTATION_PENDING;
2708 goto error;
2709 }
2710
2711 /*
2712 * Starting a session without channel is useless since after that it's not
2713 * possible to enable channel thus inform the client.
2714 */
2715 if (usess && usess->domain_global.channels) {
2716 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2717 }
2718 if (ksession) {
2719 nb_chan += ksession->channel_count;
2720 }
2721 if (!nb_chan) {
2722 ret = LTTNG_ERR_NO_CHANNEL;
2723 goto error;
2724 }
2725
2726 session->active = 1;
2727 session->rotated_after_last_stop = false;
2728 session->cleared_after_last_stop = false;
2729 if (session->output_traces && !session->current_trace_chunk) {
2730 if (!session->has_been_started) {
2731 struct lttng_trace_chunk *trace_chunk;
2732
2733 DBG("Creating initial trace chunk of session \"%s\"",
2734 session->name);
2735 trace_chunk = session_create_new_trace_chunk(
2736 session, NULL, NULL, NULL);
2737 if (!trace_chunk) {
2738 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2739 goto error;
2740 }
2741 assert(!session->current_trace_chunk);
2742 ret = session_set_trace_chunk(session, trace_chunk,
2743 NULL);
2744 lttng_trace_chunk_put(trace_chunk);
2745 if (ret) {
2746 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2747 goto error;
2748 }
2749 } else {
2750 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2751 session->name);
2752 /*
2753 * Rotate existing streams into the new chunk.
2754 * This is a "quiet" rotation has no client has
2755 * explicitly requested this operation.
2756 *
2757 * There is also no need to wait for the rotation
2758 * to complete as it will happen immediately. No data
2759 * was produced as the session was stopped, so the
2760 * rotation should happen on reception of the command.
2761 */
2762 ret = cmd_rotate_session(session, NULL, true,
2763 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2764 if (ret != LTTNG_OK) {
2765 goto error;
2766 }
2767 }
2768 }
2769
2770 /* Kernel tracing */
2771 if (ksession != NULL) {
2772 DBG("Start kernel tracing session %s", session->name);
2773 ret = start_kernel_session(ksession);
2774 if (ret != LTTNG_OK) {
2775 goto error;
2776 }
2777 }
2778
2779 /* Flag session that trace should start automatically */
2780 if (usess) {
2781 int int_ret = ust_app_start_trace_all(usess);
2782
2783 if (int_ret < 0) {
2784 ret = LTTNG_ERR_UST_START_FAIL;
2785 goto error;
2786 }
2787 }
2788
2789 /*
2790 * Open a packet in every stream of the session to ensure that viewers
2791 * can correctly identify the boundaries of the periods during which
2792 * tracing was active for this session.
2793 */
2794 ret = session_open_packets(session);
2795 if (ret != LTTNG_OK) {
2796 goto error;
2797 }
2798
2799 /*
2800 * Clear the flag that indicates that a rotation was done while the
2801 * session was stopped.
2802 */
2803 session->rotated_after_last_stop = false;
2804
2805 if (session->rotate_timer_period) {
2806 int int_ret = timer_session_rotation_schedule_timer_start(
2807 session, session->rotate_timer_period);
2808
2809 if (int_ret < 0) {
2810 ERR("Failed to enable rotate timer");
2811 ret = LTTNG_ERR_UNK;
2812 goto error;
2813 }
2814 }
2815
2816 ret = LTTNG_OK;
2817
2818 error:
2819 if (ret == LTTNG_OK) {
2820 /* Flag this after a successful start. */
2821 session->has_been_started |= 1;
2822 } else {
2823 session->active = 0;
2824 /* Restore initial state on error. */
2825 session->rotated_after_last_stop =
2826 session_rotated_after_last_stop;
2827 session->cleared_after_last_stop =
2828 session_cleared_after_last_stop;
2829 }
2830 end:
2831 return ret;
2832 }
2833
2834 /*
2835 * Command LTTNG_STOP_TRACE processed by the client thread.
2836 */
2837 int cmd_stop_trace(struct ltt_session *session)
2838 {
2839 int ret;
2840 struct ltt_kernel_session *ksession;
2841 struct ltt_ust_session *usess;
2842
2843 assert(session);
2844
2845 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2846 /* Short cut */
2847 ksession = session->kernel_session;
2848 usess = session->ust_session;
2849
2850 /* Session is not active. Skip everythong and inform the client. */
2851 if (!session->active) {
2852 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2853 goto error;
2854 }
2855
2856 ret = stop_kernel_session(ksession);
2857 if (ret != LTTNG_OK) {
2858 goto error;
2859 }
2860
2861 if (usess && usess->active) {
2862 ret = ust_app_stop_trace_all(usess);
2863 if (ret < 0) {
2864 ret = LTTNG_ERR_UST_STOP_FAIL;
2865 goto error;
2866 }
2867 }
2868
2869 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2870 session->id);
2871 /* Flag inactive after a successful stop. */
2872 session->active = 0;
2873 ret = LTTNG_OK;
2874
2875 error:
2876 return ret;
2877 }
2878
2879 /*
2880 * Set the base_path of the session only if subdir of a control uris is set.
2881 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2882 */
2883 static int set_session_base_path_from_uris(struct ltt_session *session,
2884 size_t nb_uri,
2885 struct lttng_uri *uris)
2886 {
2887 int ret;
2888 size_t i;
2889
2890 for (i = 0; i < nb_uri; i++) {
2891 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2892 uris[i].subdir[0] == '\0') {
2893 /* Not interested in these URIs */
2894 continue;
2895 }
2896
2897 if (session->base_path != NULL) {
2898 free(session->base_path);
2899 session->base_path = NULL;
2900 }
2901
2902 /* Set session base_path */
2903 session->base_path = strdup(uris[i].subdir);
2904 if (!session->base_path) {
2905 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2906 uris[i].subdir, session->name);
2907 ret = LTTNG_ERR_NOMEM;
2908 goto error;
2909 }
2910 DBG2("Setting base path \"%s\" for session \"%s\"",
2911 session->base_path, session->name);
2912 }
2913 ret = LTTNG_OK;
2914 error:
2915 return ret;
2916 }
2917
2918 /*
2919 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2920 */
2921 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2922 struct lttng_uri *uris)
2923 {
2924 int ret, i;
2925 struct ltt_kernel_session *ksess = session->kernel_session;
2926 struct ltt_ust_session *usess = session->ust_session;
2927
2928 assert(session);
2929 assert(uris);
2930 assert(nb_uri > 0);
2931
2932 /* Can't set consumer URI if the session is active. */
2933 if (session->active) {
2934 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2935 goto error;
2936 }
2937
2938 /*
2939 * Set the session base path if any. This is done inside
2940 * cmd_set_consumer_uri to preserve backward compatibility of the
2941 * previous session creation api vs the session descriptor api.
2942 */
2943 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2944 if (ret != LTTNG_OK) {
2945 goto error;
2946 }
2947
2948 /* Set the "global" consumer URIs */
2949 for (i = 0; i < nb_uri; i++) {
2950 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2951 LTTNG_DOMAIN_NONE);
2952 if (ret != LTTNG_OK) {
2953 goto error;
2954 }
2955 }
2956
2957 /* Set UST session URIs */
2958 if (session->ust_session) {
2959 for (i = 0; i < nb_uri; i++) {
2960 ret = add_uri_to_consumer(session,
2961 session->ust_session->consumer,
2962 &uris[i], LTTNG_DOMAIN_UST);
2963 if (ret != LTTNG_OK) {
2964 goto error;
2965 }
2966 }
2967 }
2968
2969 /* Set kernel session URIs */
2970 if (session->kernel_session) {
2971 for (i = 0; i < nb_uri; i++) {
2972 ret = add_uri_to_consumer(session,
2973 session->kernel_session->consumer,
2974 &uris[i], LTTNG_DOMAIN_KERNEL);
2975 if (ret != LTTNG_OK) {
2976 goto error;
2977 }
2978 }
2979 }
2980
2981 /*
2982 * Make sure to set the session in output mode after we set URI since a
2983 * session can be created without URL (thus flagged in no output mode).
2984 */
2985 session->output_traces = 1;
2986 if (ksess) {
2987 ksess->output_traces = 1;
2988 }
2989
2990 if (usess) {
2991 usess->output_traces = 1;
2992 }
2993
2994 /* All good! */
2995 ret = LTTNG_OK;
2996
2997 error:
2998 return ret;
2999 }
3000
3001 static
3002 enum lttng_error_code set_session_output_from_descriptor(
3003 struct ltt_session *session,
3004 const struct lttng_session_descriptor *descriptor)
3005 {
3006 int ret;
3007 enum lttng_error_code ret_code = LTTNG_OK;
3008 enum lttng_session_descriptor_type session_type =
3009 lttng_session_descriptor_get_type(descriptor);
3010 enum lttng_session_descriptor_output_type output_type =
3011 lttng_session_descriptor_get_output_type(descriptor);
3012 struct lttng_uri uris[2] = {};
3013 size_t uri_count = 0;
3014
3015 switch (output_type) {
3016 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
3017 goto end;
3018 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
3019 lttng_session_descriptor_get_local_output_uri(descriptor,
3020 &uris[0]);
3021 uri_count = 1;
3022 break;
3023 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
3024 lttng_session_descriptor_get_network_output_uris(descriptor,
3025 &uris[0], &uris[1]);
3026 uri_count = 2;
3027 break;
3028 default:
3029 ret_code = LTTNG_ERR_INVALID;
3030 goto end;
3031 }
3032
3033 switch (session_type) {
3034 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3035 {
3036 struct snapshot_output *new_output = NULL;
3037
3038 new_output = snapshot_output_alloc();
3039 if (!new_output) {
3040 ret_code = LTTNG_ERR_NOMEM;
3041 goto end;
3042 }
3043
3044 ret = snapshot_output_init_with_uri(session,
3045 DEFAULT_SNAPSHOT_MAX_SIZE,
3046 NULL, uris, uri_count, session->consumer,
3047 new_output, &session->snapshot);
3048 if (ret < 0) {
3049 ret_code = (ret == -ENOMEM) ?
3050 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
3051 snapshot_output_destroy(new_output);
3052 goto end;
3053 }
3054 snapshot_add_output(&session->snapshot, new_output);
3055 break;
3056 }
3057 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3058 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3059 {
3060 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
3061 break;
3062 }
3063 default:
3064 ret_code = LTTNG_ERR_INVALID;
3065 goto end;
3066 }
3067 end:
3068 return ret_code;
3069 }
3070
3071 static
3072 enum lttng_error_code cmd_create_session_from_descriptor(
3073 struct lttng_session_descriptor *descriptor,
3074 const lttng_sock_cred *creds,
3075 const char *home_path)
3076 {
3077 int ret;
3078 enum lttng_error_code ret_code;
3079 const char *session_name;
3080 struct ltt_session *new_session = NULL;
3081 enum lttng_session_descriptor_status descriptor_status;
3082
3083 session_lock_list();
3084 if (home_path) {
3085 if (*home_path != '/') {
3086 ERR("Home path provided by client is not absolute");
3087 ret_code = LTTNG_ERR_INVALID;
3088 goto end;
3089 }
3090 }
3091
3092 descriptor_status = lttng_session_descriptor_get_session_name(
3093 descriptor, &session_name);
3094 switch (descriptor_status) {
3095 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3096 break;
3097 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3098 session_name = NULL;
3099 break;
3100 default:
3101 ret_code = LTTNG_ERR_INVALID;
3102 goto end;
3103 }
3104
3105 ret_code = session_create(session_name, creds->uid, creds->gid,
3106 &new_session);
3107 if (ret_code != LTTNG_OK) {
3108 goto end;
3109 }
3110
3111 if (!session_name) {
3112 ret = lttng_session_descriptor_set_session_name(descriptor,
3113 new_session->name);
3114 if (ret) {
3115 ret_code = LTTNG_ERR_SESSION_FAIL;
3116 goto end;
3117 }
3118 }
3119
3120 if (!lttng_session_descriptor_is_output_destination_initialized(
3121 descriptor)) {
3122 /*
3123 * Only include the session's creation time in the output
3124 * destination if the name of the session itself was
3125 * not auto-generated.
3126 */
3127 ret_code = lttng_session_descriptor_set_default_output(
3128 descriptor,
3129 session_name ? &new_session->creation_time : NULL,
3130 home_path);
3131 if (ret_code != LTTNG_OK) {
3132 goto end;
3133 }
3134 } else {
3135 new_session->has_user_specified_directory =
3136 lttng_session_descriptor_has_output_directory(
3137 descriptor);
3138 }
3139
3140 switch (lttng_session_descriptor_get_type(descriptor)) {
3141 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3142 new_session->snapshot_mode = 1;
3143 break;
3144 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3145 new_session->live_timer =
3146 lttng_session_descriptor_live_get_timer_interval(
3147 descriptor);
3148 break;
3149 default:
3150 break;
3151 }
3152
3153 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3154 if (ret_code != LTTNG_OK) {
3155 goto end;
3156 }
3157 new_session->consumer->enabled = 1;
3158 ret_code = LTTNG_OK;
3159 end:
3160 /* Release reference provided by the session_create function. */
3161 session_put(new_session);
3162 if (ret_code != LTTNG_OK && new_session) {
3163 /* Release the global reference on error. */
3164 session_destroy(new_session);
3165 }
3166 session_unlock_list();
3167 return ret_code;
3168 }
3169
3170 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3171 struct lttng_session_descriptor **return_descriptor)
3172 {
3173 int ret;
3174 size_t payload_size;
3175 struct lttng_dynamic_buffer payload;
3176 struct lttng_buffer_view home_dir_view;
3177 struct lttng_buffer_view session_descriptor_view;
3178 struct lttng_session_descriptor *session_descriptor = NULL;
3179 enum lttng_error_code ret_code;
3180
3181 lttng_dynamic_buffer_init(&payload);
3182 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
3183 LTTNG_PATH_MAX) {
3184 ret_code = LTTNG_ERR_INVALID;
3185 goto error;
3186 }
3187 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3188 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3189 ret_code = LTTNG_ERR_INVALID;
3190 goto error;
3191 }
3192
3193 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3194 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3195 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3196 if (ret) {
3197 ret_code = LTTNG_ERR_NOMEM;
3198 goto error;
3199 }
3200
3201 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3202 if (ret <= 0) {
3203 ERR("Reception of session descriptor failed, aborting.");
3204 ret_code = LTTNG_ERR_SESSION_FAIL;
3205 goto error;
3206 }
3207
3208 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3209 &payload,
3210 0,
3211 cmd_ctx->lsm->u.create_session.home_dir_size);
3212 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3213 &payload,
3214 cmd_ctx->lsm->u.create_session.home_dir_size,
3215 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3216
3217 ret = lttng_session_descriptor_create_from_buffer(
3218 &session_descriptor_view, &session_descriptor);
3219 if (ret < 0) {
3220 ERR("Failed to create session descriptor from payload of \"create session\" command");
3221 ret_code = LTTNG_ERR_INVALID;
3222 goto error;
3223 }
3224
3225 /*
3226 * Sets the descriptor's auto-generated properties (name, output) if
3227 * needed.
3228 */
3229 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3230 &cmd_ctx->creds,
3231 home_dir_view.size ? home_dir_view.data : NULL);
3232 if (ret_code != LTTNG_OK) {
3233 goto error;
3234 }
3235
3236 ret_code = LTTNG_OK;
3237 *return_descriptor = session_descriptor;
3238 session_descriptor = NULL;
3239 error:
3240 lttng_dynamic_buffer_reset(&payload);
3241 lttng_session_descriptor_destroy(session_descriptor);
3242 return ret_code;
3243 }
3244
3245 static
3246 void cmd_destroy_session_reply(const struct ltt_session *session,
3247 void *_reply_context)
3248 {
3249 int ret;
3250 ssize_t comm_ret;
3251 const struct cmd_destroy_session_reply_context *reply_context =
3252 _reply_context;
3253 struct lttng_dynamic_buffer payload;
3254 struct lttcomm_session_destroy_command_header cmd_header;
3255 struct lttng_trace_archive_location *location = NULL;
3256 struct lttcomm_lttng_msg llm = {
3257 .cmd_type = LTTNG_DESTROY_SESSION,
3258 .ret_code = reply_context->destruction_status,
3259 .pid = UINT32_MAX,
3260 .cmd_header_size =
3261 sizeof(struct lttcomm_session_destroy_command_header),
3262 .data_size = 0,
3263 };
3264 size_t payload_size_before_location;
3265
3266 lttng_dynamic_buffer_init(&payload);
3267
3268 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3269 if (ret) {
3270 ERR("Failed to append session destruction message");
3271 goto error;
3272 }
3273
3274 cmd_header.rotation_state =
3275 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3276 session->rotation_state :
3277 LTTNG_ROTATION_STATE_NO_ROTATION);
3278 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3279 sizeof(cmd_header));
3280 if (ret) {
3281 ERR("Failed to append session destruction command header");
3282 goto error;
3283 }
3284
3285 if (!reply_context->implicit_rotation_on_destroy) {
3286 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3287 session->name);
3288 goto send_reply;
3289 }
3290 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3291 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3292 session->name);
3293 goto send_reply;
3294 }
3295
3296 location = session_get_trace_archive_location(session);
3297 if (!location) {
3298 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3299 session->name);
3300 goto error;
3301 }
3302
3303 payload_size_before_location = payload.size;
3304 comm_ret = lttng_trace_archive_location_serialize(location,
3305 &payload);
3306 if (comm_ret < 0) {
3307 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3308 session->name);
3309 goto error;
3310 }
3311 /* Update the message to indicate the location's length. */
3312 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3313 payload.size - payload_size_before_location;
3314 send_reply:
3315 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3316 payload.data, payload.size);
3317 if (comm_ret != (ssize_t) payload.size) {
3318 ERR("Failed to send result of the destruction of session \"%s\" to client",
3319 session->name);
3320 }
3321 error:
3322 ret = close(reply_context->reply_sock_fd);
3323 if (ret) {
3324 PERROR("Failed to close client socket in deferred session destroy reply");
3325 }
3326 lttng_dynamic_buffer_reset(&payload);
3327 free(_reply_context);
3328 }
3329
3330 /*
3331 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3332 *
3333 * Called with session lock held.
3334 */
3335 int cmd_destroy_session(struct ltt_session *session,
3336 struct notification_thread_handle *notification_thread_handle,
3337 int *sock_fd)
3338 {
3339 int ret;
3340 enum lttng_error_code destruction_last_error = LTTNG_OK;
3341 struct cmd_destroy_session_reply_context *reply_context = NULL;
3342
3343 if (sock_fd) {
3344 reply_context = zmalloc(sizeof(*reply_context));
3345 if (!reply_context) {
3346 ret = LTTNG_ERR_NOMEM;
3347 goto end;
3348 }
3349 reply_context->reply_sock_fd = *sock_fd;
3350 }
3351
3352 /* Safety net */
3353 assert(session);
3354
3355 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3356 session->id);
3357 if (session->active) {
3358 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3359 session->name);
3360 ret = cmd_stop_trace(session);
3361 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3362 /* Carry on with the destruction of the session. */
3363 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3364 session->name, lttng_strerror(-ret));
3365 destruction_last_error = ret;
3366 }
3367 }
3368
3369 if (session->rotation_schedule_timer_enabled) {
3370 if (timer_session_rotation_schedule_timer_stop(
3371 session)) {
3372 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3373 session->name);
3374 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3375 }
3376 }
3377
3378 if (session->rotate_size) {
3379 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3380 session->rotate_size = 0;
3381 }
3382
3383 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3384 /*
3385 * Perform a last rotation on destruction if rotations have
3386 * occurred during the session's lifetime.
3387 */
3388 ret = cmd_rotate_session(session, NULL, false,
3389 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3390 if (ret != LTTNG_OK) {
3391 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3392 session->name, lttng_strerror(-ret));
3393 destruction_last_error = -ret;
3394 }
3395 if (reply_context) {
3396 reply_context->implicit_rotation_on_destroy = true;
3397 }
3398 } else if (session->has_been_started && session->current_trace_chunk) {
3399 /*
3400 * The user has not triggered a session rotation. However, to
3401 * ensure all data has been consumed, the session is rotated
3402 * to a 'null' trace chunk before it is destroyed.
3403 *
3404 * This is a "quiet" rotation meaning that no notification is
3405 * emitted and no renaming of the current trace chunk takes
3406 * place.
3407 */
3408 ret = cmd_rotate_session(session, NULL, true,
3409 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3410 /*
3411 * Rotation operations may not be supported by the kernel
3412 * tracer. Hence, do not consider this implicit rotation as
3413 * a session destruction error. The library has already stopped
3414 * the session and waited for pending data; there is nothing
3415 * left to do but complete the destruction of the session.
3416 */
3417 if (ret != LTTNG_OK &&
3418 ret != -LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL) {
3419 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3420 session->name, lttng_strerror(ret));
3421 destruction_last_error = -ret;
3422 }
3423 }
3424
3425 if (session->shm_path[0]) {
3426 /*
3427 * When a session is created with an explicit shm_path,
3428 * the consumer daemon will create its shared memory files
3429 * at that location and will *not* unlink them. This is normal
3430 * as the intention of that feature is to make it possible
3431 * to retrieve the content of those files should a crash occur.
3432 *
3433 * To ensure the content of those files can be used, the
3434 * sessiond daemon will replicate the content of the metadata
3435 * cache in a metadata file.
3436 *
3437 * On clean-up, it is expected that the consumer daemon will
3438 * unlink the shared memory files and that the session daemon
3439 * will unlink the metadata file. Then, the session's directory
3440 * in the shm path can be removed.
3441 *
3442 * Unfortunately, a flaw in the design of the sessiond's and
3443 * consumerd's tear down of channels makes it impossible to
3444 * determine when the sessiond _and_ the consumerd have both
3445 * destroyed their representation of a channel. For one, the
3446 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3447 * callbacks in both daemons.
3448 *
3449 * However, it is also impossible for the sessiond to know when
3450 * the consumer daemon is done destroying its channel(s) since
3451 * it occurs as a reaction to the closing of the channel's file
3452 * descriptor. There is no resulting communication initiated
3453 * from the consumerd to the sessiond to confirm that the
3454 * operation is completed (and was successful).
3455 *
3456 * Until this is all fixed, the session daemon checks for the
3457 * removal of the session's shm path which makes it possible
3458 * to safely advertise a session as having been destroyed.
3459 *
3460 * Prior to this fix, it was not possible to reliably save
3461 * a session making use of the --shm-path option, destroy it,
3462 * and load it again. This is because the creation of the
3463 * session would fail upon seeing the session's shm path
3464 * already in existence.
3465 *
3466 * Note that none of the error paths in the check for the
3467 * directory's existence return an error. This is normal
3468 * as there isn't much that can be done. The session will
3469 * be destroyed properly, except that we can't offer the
3470 * guarantee that the same session can be re-created.
3471 */
3472 current_completion_handler = &destroy_completion_handler.handler;
3473 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3474 session->shm_path,
3475 sizeof(destroy_completion_handler.shm_path));
3476 assert(!ret);
3477 }
3478
3479 /*
3480 * The session is destroyed. However, note that the command context
3481 * still holds a reference to the session, thus delaying its destruction
3482 * _at least_ up to the point when that reference is released.
3483 */
3484 session_destroy(session);
3485 if (reply_context) {
3486 reply_context->destruction_status = destruction_last_error;
3487 ret = session_add_destroy_notifier(session,
3488 cmd_destroy_session_reply,
3489 (void *) reply_context);
3490 if (ret) {
3491 ret = LTTNG_ERR_FATAL;
3492 goto end;
3493 } else {
3494 *sock_fd = -1;
3495 }
3496 }
3497 ret = LTTNG_OK;
3498 end:
3499 return ret;
3500 }
3501
3502 /*
3503 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3504 */
3505 int cmd_register_consumer(struct ltt_session *session,
3506 enum lttng_domain_type domain, const char *sock_path,
3507 struct consumer_data *cdata)
3508 {
3509 int ret, sock;
3510 struct consumer_socket *socket = NULL;
3511
3512 assert(session);
3513 assert(cdata);
3514 assert(sock_path);
3515
3516 switch (domain) {
3517 case LTTNG_DOMAIN_KERNEL:
3518 {
3519 struct ltt_kernel_session *ksess = session->kernel_session;
3520
3521 assert(ksess);
3522
3523 /* Can't register a consumer if there is already one */
3524 if (ksess->consumer_fds_sent != 0) {
3525 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3526 goto error;
3527 }
3528
3529 sock = lttcomm_connect_unix_sock(sock_path);
3530 if (sock < 0) {
3531 ret = LTTNG_ERR_CONNECT_FAIL;
3532 goto error;
3533 }
3534 cdata->cmd_sock = sock;
3535
3536 socket = consumer_allocate_socket(&cdata->cmd_sock);
3537 if (socket == NULL) {
3538 ret = close(sock);
3539 if (ret < 0) {
3540 PERROR("close register consumer");
3541 }
3542 cdata->cmd_sock = -1;
3543 ret = LTTNG_ERR_FATAL;
3544 goto error;
3545 }
3546
3547 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3548 if (socket->lock == NULL) {
3549 PERROR("zmalloc pthread mutex");
3550 ret = LTTNG_ERR_FATAL;
3551 goto error;
3552 }
3553 pthread_mutex_init(socket->lock, NULL);
3554 socket->registered = 1;
3555
3556 rcu_read_lock();
3557 consumer_add_socket(socket, ksess->consumer);
3558 rcu_read_unlock();
3559
3560 pthread_mutex_lock(&cdata->pid_mutex);
3561 cdata->pid = -1;
3562 pthread_mutex_unlock(&cdata->pid_mutex);
3563
3564 break;
3565 }
3566 default:
3567 /* TODO: Userspace tracing */
3568 ret = LTTNG_ERR_UND;
3569 goto error;
3570 }
3571
3572 return LTTNG_OK;
3573
3574 error:
3575 if (socket) {
3576 consumer_destroy_socket(socket);
3577 }
3578 return ret;
3579 }
3580
3581 /*
3582 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3583 */
3584 ssize_t cmd_list_domains(struct ltt_session *session,
3585 struct lttng_domain **domains)
3586 {
3587 int ret, index = 0;
3588 ssize_t nb_dom = 0;
3589 struct agent *agt;
3590 struct lttng_ht_iter iter;
3591
3592 if (session->kernel_session != NULL) {
3593 DBG3("Listing domains found kernel domain");
3594 nb_dom++;
3595 }
3596
3597 if (session->ust_session != NULL) {
3598 DBG3("Listing domains found UST global domain");
3599 nb_dom++;
3600
3601 rcu_read_lock();
3602 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3603 agt, node.node) {
3604 if (agt->being_used) {
3605 nb_dom++;
3606 }
3607 }
3608 rcu_read_unlock();
3609 }
3610
3611 if (!nb_dom) {
3612 goto end;
3613 }
3614
3615 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3616 if (*domains == NULL) {
3617 ret = LTTNG_ERR_FATAL;
3618 goto error;
3619 }
3620
3621 if (session->kernel_session != NULL) {
3622 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3623
3624 /* Kernel session buffer type is always GLOBAL */
3625 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3626
3627 index++;
3628 }
3629
3630 if (session->ust_session != NULL) {
3631 (*domains)[index].type = LTTNG_DOMAIN_UST;
3632 (*domains)[index].buf_type = session->ust_session->buffer_type;
3633 index++;
3634
3635 rcu_read_lock();
3636 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3637 agt, node.node) {
3638 if (agt->being_used) {
3639 (*domains)[index].type = agt->domain;
3640 (*domains)[index].buf_type = session->ust_session->buffer_type;
3641 index++;
3642 }
3643 }
3644 rcu_read_unlock();
3645 }
3646 end:
3647 return nb_dom;
3648
3649 error:
3650 /* Return negative value to differentiate return code */
3651 return -ret;
3652 }
3653
3654
3655 /*
3656 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3657 */
3658 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3659 struct ltt_session *session, struct lttng_channel **channels)
3660 {
3661 ssize_t nb_chan = 0, payload_size = 0, ret;
3662
3663 switch (domain) {
3664 case LTTNG_DOMAIN_KERNEL:
3665 if (session->kernel_session != NULL) {
3666 nb_chan = session->kernel_session->channel_count;
3667 }
3668 DBG3("Number of kernel channels %zd", nb_chan);
3669 if (nb_chan <= 0) {
3670 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3671 goto end;
3672 }
3673 break;
3674 case LTTNG_DOMAIN_UST:
3675 if (session->ust_session != NULL) {
3676 rcu_read_lock();
3677 nb_chan = lttng_ht_get_count(
3678 session->ust_session->domain_global.channels);
3679 rcu_read_unlock();
3680 }
3681 DBG3("Number of UST global channels %zd", nb_chan);
3682 if (nb_chan < 0) {
3683 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3684 goto end;
3685 }
3686 break;
3687 default:
3688 ret = -LTTNG_ERR_UND;
3689 goto end;
3690 }
3691
3692 if (nb_chan > 0) {
3693 const size_t channel_size = sizeof(struct lttng_channel) +
3694 sizeof(struct lttng_channel_extended);
3695 struct lttng_channel_extended *channel_exts;
3696
3697 payload_size = nb_chan * channel_size;
3698 *channels = zmalloc(payload_size);
3699 if (*channels == NULL) {
3700 ret = -LTTNG_ERR_FATAL;
3701 goto end;
3702 }
3703
3704 channel_exts = ((void *) *channels) +
3705 (nb_chan * sizeof(struct lttng_channel));
3706 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3707 if (ret != LTTNG_OK) {
3708 free(*channels);
3709 *channels = NULL;
3710 goto end;
3711 }
3712 } else {
3713 *channels = NULL;
3714 }
3715
3716 ret = payload_size;
3717 end:
3718 return ret;
3719 }
3720
3721 /*
3722 * Command LTTNG_LIST_EVENTS processed by the client thread.
3723 */
3724 ssize_t cmd_list_events(enum lttng_domain_type domain,
3725 struct ltt_session *session, char *channel_name,
3726 struct lttng_event **events, size_t *total_size)
3727 {
3728 int ret = 0;
3729 ssize_t nb_event = 0;
3730
3731 switch (domain) {
3732 case LTTNG_DOMAIN_KERNEL:
3733 if (session->kernel_session != NULL) {
3734 nb_event = list_lttng_kernel_events(channel_name,
3735 session->kernel_session, events,
3736 total_size);
3737 }
3738 break;
3739 case LTTNG_DOMAIN_UST:
3740 {
3741 if (session->ust_session != NULL) {
3742 nb_event = list_lttng_ust_global_events(channel_name,
3743 &session->ust_session->domain_global, events,
3744 total_size);
3745 }
3746 break;
3747 }
3748 case LTTNG_DOMAIN_LOG4J:
3749 case LTTNG_DOMAIN_JUL:
3750 case LTTNG_DOMAIN_PYTHON:
3751 if (session->ust_session) {
3752 struct lttng_ht_iter iter;
3753 struct agent *agt;
3754
3755 rcu_read_lock();
3756 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3757 &iter.iter, agt, node.node) {
3758 if (agt->domain == domain) {
3759 nb_event = list_lttng_agent_events(
3760 agt, events,
3761 total_size);
3762 break;
3763 }
3764 }
3765 rcu_read_unlock();
3766 }
3767 break;
3768 default:
3769 ret = LTTNG_ERR_UND;
3770 goto error;
3771 }
3772
3773 return nb_event;
3774
3775 error:
3776 /* Return negative value to differentiate return code */
3777 return -ret;
3778 }
3779
3780 /*
3781 * Using the session list, filled a lttng_session array to send back to the
3782 * client for session listing.
3783 *
3784 * The session list lock MUST be acquired before calling this function. Use
3785 * session_lock_list() and session_unlock_list().
3786 */
3787 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3788 size_t session_count, uid_t uid, gid_t gid)
3789 {
3790 int ret;
3791 unsigned int i = 0;
3792 struct ltt_session *session;
3793 struct ltt_session_list *list = session_get_list();
3794 struct lttng_session_extended *extended =
3795 (typeof(extended)) (&sessions[session_count]);
3796
3797 DBG("Getting all available session for UID %d GID %d",
3798 uid, gid);
3799 /*
3800 * Iterate over session list and append data after the control struct in
3801 * the buffer.
3802 */
3803 cds_list_for_each_entry(session, &list->head, list) {
3804 if (!session_get(session)) {
3805 continue;
3806 }
3807 /*
3808 * Only list the sessions the user can control.
3809 */
3810 if (!session_access_ok(session, uid, gid) ||
3811 session->destroyed) {
3812 session_put(session);
3813 continue;
3814 }
3815
3816 struct ltt_kernel_session *ksess = session->kernel_session;
3817 struct ltt_ust_session *usess = session->ust_session;
3818
3819 if (session->consumer->type == CONSUMER_DST_NET ||
3820 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3821 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3822 ret = build_network_session_path(sessions[i].path,
3823 sizeof(sessions[i].path), session);
3824 } else {
3825 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3826 session->consumer->dst.session_root_path);
3827 }
3828 if (ret < 0) {
3829 PERROR("snprintf session path");
3830 session_put(session);
3831 continue;
3832 }
3833
3834 strncpy(sessions[i].name, session->name, NAME_MAX);
3835 sessions[i].name[NAME_MAX - 1] = '\0';
3836 sessions[i].enabled = session->active;
3837 sessions[i].snapshot_mode = session->snapshot_mode;
3838 sessions[i].live_timer_interval = session->live_timer;
3839 extended[i].creation_time.value = (uint64_t) session->creation_time;
3840 extended[i].creation_time.is_set = 1;
3841 i++;
3842 session_put(session);
3843 }
3844 }
3845
3846 /*
3847 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3848 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3849 */
3850 int cmd_data_pending(struct ltt_session *session)
3851 {
3852 int ret;
3853 struct ltt_kernel_session *ksess = session->kernel_session;
3854 struct ltt_ust_session *usess = session->ust_session;
3855
3856 assert(session);
3857
3858 DBG("Data pending for session %s", session->name);
3859
3860 /* Session MUST be stopped to ask for data availability. */
3861 if (session->active) {
3862 ret = LTTNG_ERR_SESSION_STARTED;
3863 goto error;
3864 } else {
3865 /*
3866 * If stopped, just make sure we've started before else the above call
3867 * will always send that there is data pending.
3868 *
3869 * The consumer assumes that when the data pending command is received,
3870 * the trace has been started before or else no output data is written
3871 * by the streams which is a condition for data pending. So, this is
3872 * *VERY* important that we don't ask the consumer before a start
3873 * trace.
3874 */
3875 if (!session->has_been_started) {
3876 ret = 0;
3877 goto error;
3878 }
3879 }
3880
3881 /* A rotation is still pending, we have to wait. */
3882 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3883 DBG("Rotate still pending for session %s", session->name);
3884 ret = 1;
3885 goto error;
3886 }
3887
3888 if (ksess && ksess->consumer) {
3889 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3890 if (ret == 1) {
3891 /* Data is still being extracted for the kernel. */
3892 goto error;
3893 }
3894 }
3895
3896 if (usess && usess->consumer) {
3897 ret = consumer_is_data_pending(usess->id, usess->consumer);
3898 if (ret == 1) {
3899 /* Data is still being extracted for the kernel. */
3900 goto error;
3901 }
3902 }
3903
3904 /* Data is ready to be read by a viewer */
3905 ret = 0;
3906
3907 error:
3908 return ret;
3909 }
3910
3911 /*
3912 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3913 *
3914 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3915 */
3916 int cmd_snapshot_add_output(struct ltt_session *session,
3917 const struct lttng_snapshot_output *output, uint32_t *id)
3918 {
3919 int ret;
3920 struct snapshot_output *new_output;
3921
3922 assert(session);
3923 assert(output);
3924
3925 DBG("Cmd snapshot add output for session %s", session->name);
3926
3927 /*
3928 * Can't create an output if the session is not set in no-output mode.
3929 */
3930 if (session->output_traces) {
3931 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3932 goto error;
3933 }
3934
3935 if (session->has_non_mmap_channel) {
3936 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3937 goto error;
3938 }
3939
3940 /* Only one output is allowed until we have the "tee" feature. */
3941 if (session->snapshot.nb_output == 1) {
3942 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3943 goto error;
3944 }
3945
3946 new_output = snapshot_output_alloc();
3947 if (!new_output) {
3948 ret = LTTNG_ERR_NOMEM;
3949 goto error;
3950 }
3951
3952 ret = snapshot_output_init(session, output->max_size, output->name,
3953 output->ctrl_url, output->data_url, session->consumer, new_output,
3954 &session->snapshot);
3955 if (ret < 0) {
3956 if (ret == -ENOMEM) {
3957 ret = LTTNG_ERR_NOMEM;
3958 } else {
3959 ret = LTTNG_ERR_INVALID;
3960 }
3961 goto free_error;
3962 }
3963
3964 rcu_read_lock();
3965 snapshot_add_output(&session->snapshot, new_output);
3966 if (id) {
3967 *id = new_output->id;
3968 }
3969 rcu_read_unlock();
3970
3971 return LTTNG_OK;
3972
3973 free_error:
3974 snapshot_output_destroy(new_output);
3975 error:
3976 return ret;
3977 }
3978
3979 /*
3980 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3981 *
3982 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3983 */
3984 int cmd_snapshot_del_output(struct ltt_session *session,
3985 const struct lttng_snapshot_output *output)
3986 {
3987 int ret;
3988 struct snapshot_output *sout = NULL;
3989
3990 assert(session);
3991 assert(output);
3992
3993 rcu_read_lock();
3994
3995 /*
3996 * Permission denied to create an output if the session is not
3997 * set in no output mode.
3998 */
3999 if (session->output_traces) {
4000 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4001 goto error;
4002 }
4003
4004 if (output->id) {
4005 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
4006 session->name);
4007 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
4008 } else if (*output->name != '\0') {
4009 DBG("Cmd snapshot del output name %s for session %s", output->name,
4010 session->name);
4011 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
4012 }
4013 if (!sout) {
4014 ret = LTTNG_ERR_INVALID;
4015 goto error;
4016 }
4017
4018 snapshot_delete_output(&session->snapshot, sout);
4019 snapshot_output_destroy(sout);
4020 ret = LTTNG_OK;
4021
4022 error:
4023 rcu_read_unlock();
4024 return ret;
4025 }
4026
4027 /*
4028 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
4029 *
4030 * If no output is available, outputs is untouched and 0 is returned.
4031 *
4032 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
4033 */
4034 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
4035 struct lttng_snapshot_output **outputs)
4036 {
4037 int ret, idx = 0;
4038 struct lttng_snapshot_output *list = NULL;
4039 struct lttng_ht_iter iter;
4040 struct snapshot_output *output;
4041
4042 assert(session);
4043 assert(outputs);
4044
4045 DBG("Cmd snapshot list outputs for session %s", session->name);
4046
4047 /*
4048 * Permission denied to create an output if the session is not
4049 * set in no output mode.
4050 */
4051 if (session->output_traces) {
4052 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4053 goto end;
4054 }
4055
4056 if (session->snapshot.nb_output == 0) {
4057 ret = 0;
4058 goto end;
4059 }
4060
4061 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
4062 if (!list) {
4063 ret = -LTTNG_ERR_NOMEM;
4064 goto end;
4065 }
4066
4067 /* Copy list from session to the new list object. */
4068 rcu_read_lock();
4069 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
4070 output, node.node) {
4071 assert(output->consumer);
4072 list[idx].id = output->id;
4073 list[idx].max_size = output->max_size;
4074 if (lttng_strncpy(list[idx].name, output->name,
4075 sizeof(list[idx].name))) {
4076 ret = -LTTNG_ERR_INVALID;
4077 goto error;
4078 }
4079 if (output->consumer->type == CONSUMER_DST_LOCAL) {
4080 if (lttng_strncpy(list[idx].ctrl_url,
4081 output->consumer->dst.session_root_path,
4082 sizeof(list[idx].ctrl_url))) {
4083 ret = -LTTNG_ERR_INVALID;
4084 goto error;
4085 }
4086 } else {
4087 /* Control URI. */
4088 ret = uri_to_str_url(&output->consumer->dst.net.control,
4089 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
4090 if (ret < 0) {
4091 ret = -LTTNG_ERR_NOMEM;
4092 goto error;
4093 }
4094
4095 /* Data URI. */
4096 ret = uri_to_str_url(&output->consumer->dst.net.data,
4097 list[idx].data_url, sizeof(list[idx].data_url));
4098 if (ret < 0) {
4099 ret = -LTTNG_ERR_NOMEM;
4100 goto error;
4101 }
4102 }
4103 idx++;
4104 }
4105
4106 *outputs = list;
4107 list = NULL;
4108 ret = session->snapshot.nb_output;
4109 error:
4110 rcu_read_unlock();
4111 free(list);
4112 end:
4113 return ret;
4114 }
4115
4116 /*
4117 * Check if we can regenerate the metadata for this session.
4118 * Only kernel, UST per-uid and non-live sessions are supported.
4119 *
4120 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
4121 */
4122 static
4123 int check_regenerate_metadata_support(struct ltt_session *session)
4124 {
4125 int ret;
4126
4127 assert(session);
4128
4129 if (session->live_timer != 0) {
4130 ret = LTTNG_ERR_LIVE_SESSION;
4131 goto end;
4132 }
4133 if (!session->active) {
4134 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4135 goto end;
4136 }
4137 if (session->ust_session) {
4138 switch (session->ust_session->buffer_type) {
4139 case LTTNG_BUFFER_PER_UID:
4140 break;
4141 case LTTNG_BUFFER_PER_PID:
4142 ret = LTTNG_ERR_PER_PID_SESSION;
4143 goto end;
4144 default:
4145 assert(0);
4146 ret = LTTNG_ERR_UNK;
4147 goto end;
4148 }
4149 }
4150 if (session->consumer->type == CONSUMER_DST_NET &&
4151 session->consumer->relay_minor_version < 8) {
4152 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
4153 goto end;
4154 }
4155 ret = 0;
4156
4157 end:
4158 return ret;
4159 }
4160
4161 static
4162 int clear_metadata_file(int fd)
4163 {
4164 int ret;
4165 off_t lseek_ret;
4166
4167 lseek_ret = lseek(fd, 0, SEEK_SET);
4168 if (lseek_ret < 0) {
4169 PERROR("lseek");
4170 ret = -1;
4171 goto end;
4172 }
4173
4174 ret = ftruncate(fd, 0);
4175 if (ret < 0) {
4176 PERROR("ftruncate");
4177 goto end;
4178 }
4179
4180 end:
4181 return ret;
4182 }
4183
4184 static
4185 int ust_regenerate_metadata(struct ltt_ust_session *usess)
4186 {
4187 int ret = 0;
4188 struct buffer_reg_uid *uid_reg = NULL;
4189 struct buffer_reg_session *session_reg = NULL;
4190
4191 rcu_read_lock();
4192 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
4193 struct ust_registry_session *registry;
4194 struct ust_registry_channel *chan;
4195 struct lttng_ht_iter iter_chan;
4196
4197 session_reg = uid_reg->registry;
4198 registry = session_reg->reg.ust;
4199
4200 pthread_mutex_lock(&registry->lock);
4201 registry->metadata_len_sent = 0;
4202 memset(registry->metadata, 0, registry->metadata_alloc_len);
4203 registry->metadata_len = 0;
4204 registry->metadata_version++;
4205 if (registry->metadata_fd > 0) {
4206 /* Clear the metadata file's content. */
4207 ret = clear_metadata_file(registry->metadata_fd);
4208 if (ret) {
4209 pthread_mutex_unlock(&registry->lock);
4210 goto end;
4211 }
4212 }
4213
4214 ret = ust_metadata_session_statedump(registry, NULL,
4215 registry->major, registry->minor);
4216 if (ret) {
4217 pthread_mutex_unlock(&registry->lock);
4218 ERR("Failed to generate session metadata (err = %d)",
4219 ret);
4220 goto end;
4221 }
4222 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
4223 chan, node.node) {
4224 struct ust_registry_event *event;
4225 struct lttng_ht_iter iter_event;
4226
4227 ret = ust_metadata_channel_statedump(registry, chan);
4228 if (ret) {
4229 pthread_mutex_unlock(&registry->lock);
4230 ERR("Failed to generate channel metadata "
4231 "(err = %d)", ret);
4232 goto end;
4233 }
4234 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
4235 event, node.node) {
4236 ret = ust_metadata_event_statedump(registry,
4237 chan, event);
4238 if (ret) {
4239 pthread_mutex_unlock(&registry->lock);
4240 ERR("Failed to generate event metadata "
4241 "(err = %d)", ret);
4242 goto end;
4243 }
4244 }
4245 }
4246 pthread_mutex_unlock(&registry->lock);
4247 }
4248
4249 end:
4250 rcu_read_unlock();
4251 return ret;
4252 }
4253
4254 /*
4255 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
4256 *
4257 * Ask the consumer to truncate the existing metadata file(s) and
4258 * then regenerate the metadata. Live and per-pid sessions are not
4259 * supported and return an error.
4260 *
4261 * Return 0 on success or else a LTTNG_ERR code.
4262 */
4263 int cmd_regenerate_metadata(struct ltt_session *session)
4264 {
4265 int ret;
4266
4267 assert(session);
4268
4269 ret = check_regenerate_metadata_support(session);
4270 if (ret) {
4271 goto end;
4272 }
4273
4274 if (session->kernel_session) {
4275 ret = kernctl_session_regenerate_metadata(
4276 session->kernel_session->fd);
4277 if (ret < 0) {
4278 ERR("Failed to regenerate the kernel metadata");
4279 goto end;
4280 }
4281 }
4282
4283 if (session->ust_session) {
4284 ret = ust_regenerate_metadata(session->ust_session);
4285 if (ret < 0) {
4286 ERR("Failed to regenerate the UST metadata");
4287 goto end;
4288 }
4289 }
4290 DBG("Cmd metadata regenerate for session %s", session->name);
4291 ret = LTTNG_OK;
4292
4293 end:
4294 return ret;
4295 }
4296
4297 /*
4298 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
4299 *
4300 * Ask the tracer to regenerate a new statedump.
4301 *
4302 * Return 0 on success or else a LTTNG_ERR code.
4303 */
4304 int cmd_regenerate_statedump(struct ltt_session *session)
4305 {
4306 int ret;
4307
4308 assert(session);
4309
4310 if (!session->active) {
4311 ret = LTTNG_ERR_SESSION_NOT_STARTED;
4312 goto end;
4313 }
4314
4315 if (session->kernel_session) {
4316 ret = kernctl_session_regenerate_statedump(
4317 session->kernel_session->fd);
4318 /*
4319 * Currently, the statedump in kernel can only fail if out
4320 * of memory.
4321 */
4322 if (ret < 0) {
4323 if (ret == -ENOMEM) {
4324 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
4325 } else {
4326 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4327 }
4328 ERR("Failed to regenerate the kernel statedump");
4329 goto end;
4330 }
4331 }
4332
4333 if (session->ust_session) {
4334 ret = ust_app_regenerate_statedump_all(session->ust_session);
4335 /*
4336 * Currently, the statedump in UST always returns 0.
4337 */
4338 if (ret < 0) {
4339 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
4340 ERR("Failed to regenerate the UST statedump");
4341 goto end;
4342 }
4343 }
4344 DBG("Cmd regenerate statedump for session %s", session->name);
4345 ret = LTTNG_OK;
4346
4347 end:
4348 return ret;
4349 }
4350
4351 int cmd_register_trigger(struct command_ctx *cmd_ctx, int sock,
4352 struct notification_thread_handle *notification_thread)
4353 {
4354 int ret;
4355 size_t trigger_len;
4356 ssize_t sock_recv_len;
4357 struct lttng_trigger *trigger = NULL;
4358 struct lttng_buffer_view view;
4359 struct lttng_dynamic_buffer trigger_buffer;
4360
4361 lttng_dynamic_buffer_init(&trigger_buffer);
4362 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4363 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4364 if (ret) {
4365 ret = LTTNG_ERR_NOMEM;
4366 goto end;
4367 }
4368
4369 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4370 trigger_len);
4371 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4372 ERR("Failed to receive \"register trigger\" command payload");
4373 /* TODO: should this be a new error enum ? */
4374 ret = LTTNG_ERR_INVALID_TRIGGER;
4375 goto end;
4376 }
4377
4378 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4379 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4380 trigger_len) {
4381 ERR("Invalid trigger payload received in \"register trigger\" command");
4382 ret = LTTNG_ERR_INVALID_TRIGGER;
4383 goto end;
4384 }
4385
4386 ret = notification_thread_command_register_trigger(notification_thread,
4387 trigger);
4388 /* Ownership of trigger was transferred. */
4389 trigger = NULL;
4390 end:
4391 lttng_trigger_destroy(trigger);
4392 lttng_dynamic_buffer_reset(&trigger_buffer);
4393 return ret;
4394 }
4395
4396 int cmd_unregister_trigger(struct command_ctx *cmd_ctx, int sock,
4397 struct notification_thread_handle *notification_thread)
4398 {
4399 int ret;
4400 size_t trigger_len;
4401 ssize_t sock_recv_len;
4402 struct lttng_trigger *trigger = NULL;
4403 struct lttng_buffer_view view;
4404 struct lttng_dynamic_buffer trigger_buffer;
4405
4406 lttng_dynamic_buffer_init(&trigger_buffer);
4407 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4408 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4409 if (ret) {
4410 ret = LTTNG_ERR_NOMEM;
4411 goto end;
4412 }
4413
4414 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4415 trigger_len);
4416 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4417 ERR("Failed to receive \"unregister trigger\" command payload");
4418 /* TODO: should this be a new error enum ? */
4419 ret = LTTNG_ERR_INVALID_TRIGGER;
4420 goto end;
4421 }
4422
4423 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4424 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4425 trigger_len) {
4426 ERR("Invalid trigger payload received in \"unregister trigger\" command");
4427 ret = LTTNG_ERR_INVALID_TRIGGER;
4428 goto end;
4429 }
4430
4431 ret = notification_thread_command_unregister_trigger(notification_thread,
4432 trigger);
4433 end:
4434 lttng_trigger_destroy(trigger);
4435 lttng_dynamic_buffer_reset(&trigger_buffer);
4436 return ret;
4437 }
4438
4439 /*
4440 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4441 * snapshot output is *not* set with a remote destination.
4442 *
4443 * Return LTTNG_OK on success or a LTTNG_ERR code.
4444 */
4445 static enum lttng_error_code set_relayd_for_snapshot(
4446 struct consumer_output *output,
4447 const struct ltt_session *session)
4448 {
4449 enum lttng_error_code status = LTTNG_OK;
4450 struct lttng_ht_iter iter;
4451 struct consumer_socket *socket;
4452 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
4453 const char *base_path;
4454
4455 assert(output);
4456 assert(session);
4457
4458 DBG2("Set relayd object from snapshot output");
4459
4460 if (session->current_trace_chunk) {
4461 enum lttng_trace_chunk_status chunk_status =
4462 lttng_trace_chunk_get_id(
4463 session->current_trace_chunk,
4464 &current_chunk_id.value);
4465
4466 if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK) {
4467 current_chunk_id.is_set = true;
4468 } else {
4469 ERR("Failed to get current trace chunk id");
4470 status = LTTNG_ERR_UNK;
4471 goto error;
4472 }
4473 }
4474
4475 /* Ignore if snapshot consumer output is not network. */
4476 if (output->type != CONSUMER_DST_NET) {
4477 goto error;
4478 }
4479
4480 /*
4481 * The snapshot record URI base path overrides the session
4482 * base path.
4483 */
4484 if (output->dst.net.control.subdir[0] != '\0') {
4485 base_path = output->dst.net.control.subdir;
4486 } else {
4487 base_path = session->base_path;
4488 }
4489
4490 /*
4491 * For each consumer socket, create and send the relayd object of the
4492 * snapshot output.
4493 */
4494 rcu_read_lock();
4495 cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
4496 socket, node.node) {
4497 pthread_mutex_lock(socket->lock);
4498 status = send_consumer_relayd_sockets(0, session->id,
4499 output, socket,
4500 session->name, session->hostname,
4501 base_path,
4502 session->live_timer,
4503 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
4504 session->creation_time,
4505 session->name_contains_creation_time);
4506 pthread_mutex_unlock(socket->lock);
4507 if (status != LTTNG_OK) {
4508 rcu_read_unlock();
4509 goto error;
4510 }
4511 }
4512 rcu_read_unlock();
4513
4514 error:
4515 return status;
4516 }
4517
4518 /*
4519 * Record a kernel snapshot.
4520 *
4521 * Return LTTNG_OK on success or a LTTNG_ERR code.
4522 */
4523 static enum lttng_error_code record_kernel_snapshot(
4524 struct ltt_kernel_session *ksess,
4525 const struct consumer_output *output,
4526 const struct ltt_session *session,
4527 int wait, uint64_t nb_packets_per_stream)
4528 {
4529 enum lttng_error_code status;
4530
4531 assert(ksess);
4532 assert(output);
4533 assert(session);
4534
4535 status = kernel_snapshot_record(
4536 ksess, output, wait, nb_packets_per_stream);
4537 return status;
4538 }
4539
4540 /*
4541 * Record a UST snapshot.
4542 *
4543 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
4544 */
4545 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
4546 const struct consumer_output *output,
4547 const struct ltt_session *session,
4548 int wait, uint64_t nb_packets_per_stream)
4549 {
4550 enum lttng_error_code status;
4551
4552 assert(usess);
4553 assert(output);
4554 assert(session);
4555
4556 status = ust_app_snapshot_record(
4557 usess, output, wait, nb_packets_per_stream);
4558 return status;
4559 }
4560
4561 static
4562 uint64_t get_session_size_one_more_packet_per_stream(
4563 const struct ltt_session *session, uint64_t cur_nr_packets)
4564 {
4565 uint64_t tot_size = 0;
4566
4567 if (session->kernel_session) {
4568 struct ltt_kernel_channel *chan;
4569 const struct ltt_kernel_session *ksess =
4570 session->kernel_session;
4571
4572 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
4573 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
4574 /*
4575 * Don't take channel into account if we
4576 * already grab all its packets.
4577 */
4578 continue;
4579 }
4580 tot_size += chan->channel->attr.subbuf_size
4581 * chan->stream_count;
4582 }
4583 }
4584
4585 if (session->ust_session) {
4586 const struct ltt_ust_session *usess = session->ust_session;
4587
4588 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
4589 cur_nr_packets);
4590 }
4591
4592 return tot_size;
4593 }
4594
4595 /*
4596 * Calculate the number of packets we can grab from each stream that
4597 * fits within the overall snapshot max size.
4598 *
4599 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
4600 * the number of packets per stream.
4601 *
4602 * TODO: this approach is not perfect: we consider the worse case
4603 * (packet filling the sub-buffers) as an upper bound, but we could do
4604 * better if we do this calculation while we actually grab the packet
4605 * content: we would know how much padding we don't actually store into
4606 * the file.
4607 *
4608 * This algorithm is currently bounded by the number of packets per
4609 * stream.
4610 *
4611 * Since we call this algorithm before actually grabbing the data, it's
4612 * an approximation: for instance, applications could appear/disappear
4613 * in between this call and actually grabbing data.
4614 */
4615 static
4616 int64_t get_session_nb_packets_per_stream(const struct ltt_session *session,
4617 uint64_t max_size)
4618 {
4619 int64_t size_left;
4620 uint64_t cur_nb_packets = 0;
4621
4622 if (!max_size) {
4623 return 0; /* Infinite */
4624 }
4625
4626 size_left = max_size;
4627 for (;;) {
4628 uint64_t one_more_packet_tot_size;
4629
4630 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(
4631 session, cur_nb_packets);
4632 if (!one_more_packet_tot_size) {
4633 /* We are already grabbing all packets. */
4634 break;
4635 }
4636 size_left -= one_more_packet_tot_size;
4637 if (size_left < 0) {
4638 break;
4639 }
4640 cur_nb_packets++;
4641 }
4642 if (!cur_nb_packets && size_left != max_size) {
4643 /* Not enough room to grab one packet of each stream, error. */
4644 return -1;
4645 }
4646 return cur_nb_packets;
4647 }
4648
4649 static
4650 enum lttng_error_code snapshot_record(struct ltt_session *session,
4651 const struct snapshot_output *snapshot_output, int wait)
4652 {
4653 int64_t nb_packets_per_stream;
4654 char snapshot_chunk_name[LTTNG_NAME_MAX];
4655 int ret;
4656 enum lttng_error_code ret_code = LTTNG_OK;
4657 struct lttng_trace_chunk *snapshot_trace_chunk;
4658 struct consumer_output *original_ust_consumer_output = NULL;
4659 struct consumer_output *original_kernel_consumer_output = NULL;
4660 struct consumer_output *snapshot_ust_consumer_output = NULL;
4661 struct consumer_output *snapshot_kernel_consumer_output = NULL;
4662
4663 ret = snprintf(snapshot_chunk_name, sizeof(snapshot_chunk_name),
4664 "%s-%s-%" PRIu64,
4665 snapshot_output->name,
4666 snapshot_output->datetime,
4667 snapshot_output->nb_snapshot);
4668 if (ret < 0 || ret >= sizeof(snapshot_chunk_name)) {
4669 ERR("Failed to format snapshot name");
4670 ret_code = LTTNG_ERR_INVALID;
4671 goto error;
4672 }
4673 DBG("Recording snapshot \"%s\" for session \"%s\" with chunk name \"%s\"",
4674 snapshot_output->name, session->name,
4675 snapshot_chunk_name);
4676 if (!session->kernel_session && !session->ust_session) {
4677 ERR("Failed to record snapshot as no channels exist");
4678 ret_code = LTTNG_ERR_NO_CHANNEL;
4679 goto error;
4680 }
4681
4682 if (session->kernel_session) {
4683 original_kernel_consumer_output =
4684 session->kernel_session->consumer;
4685 snapshot_kernel_consumer_output =
4686 consumer_copy_output(snapshot_output->consumer);
4687 strcpy(snapshot_kernel_consumer_output->chunk_path,
4688 snapshot_chunk_name);
4689
4690 /* Copy the original domain subdir. */
4691 strcpy(snapshot_kernel_consumer_output->domain_subdir,
4692 original_kernel_consumer_output->domain_subdir);
4693
4694 ret = consumer_copy_sockets(snapshot_kernel_consumer_output,
4695 original_kernel_consumer_output);
4696 if (ret < 0) {
4697 ERR("Failed to copy consumer sockets from snapshot output configuration");
4698 ret_code = LTTNG_ERR_NOMEM;
4699 goto error;
4700 }
4701 ret_code = set_relayd_for_snapshot(
4702 snapshot_kernel_consumer_output, session);
4703 if (ret_code != LTTNG_OK) {
4704 ERR("Failed to setup relay daemon for kernel tracer snapshot");
4705 goto error;
4706 }
4707 session->kernel_session->consumer =
4708 snapshot_kernel_consumer_output;
4709 }
4710 if (session->ust_session) {
4711 original_ust_consumer_output = session->ust_session->consumer;
4712 snapshot_ust_consumer_output =
4713 consumer_copy_output(snapshot_output->consumer);
4714 strcpy(snapshot_ust_consumer_output->chunk_path,
4715 snapshot_chunk_name);
4716
4717 /* Copy the original domain subdir. */
4718 strcpy(snapshot_ust_consumer_output->domain_subdir,
4719 original_ust_consumer_output->domain_subdir);
4720
4721 ret = consumer_copy_sockets(snapshot_ust_consumer_output,
4722 original_ust_consumer_output);
4723 if (ret < 0) {
4724 ERR("Failed to copy consumer sockets from snapshot output configuration");
4725 ret_code = LTTNG_ERR_NOMEM;
4726 goto error;
4727 }
4728 ret_code = set_relayd_for_snapshot(
4729 snapshot_ust_consumer_output, session);
4730 if (ret_code != LTTNG_OK) {
4731 ERR("Failed to setup relay daemon for userspace tracer snapshot");
4732 goto error;
4733 }
4734 session->ust_session->consumer =
4735 snapshot_ust_consumer_output;
4736 }
4737
4738 snapshot_trace_chunk = session_create_new_trace_chunk(session,
4739 snapshot_kernel_consumer_output ?:
4740 snapshot_ust_consumer_output,
4741 consumer_output_get_base_path(
4742 snapshot_output->consumer),
4743 snapshot_chunk_name);
4744 if (!snapshot_trace_chunk) {
4745 ERR("Failed to create temporary trace chunk to record a snapshot of session \"%s\"",
4746 session->name);
4747 ret_code = LTTNG_ERR_CREATE_DIR_FAIL;
4748 goto error;
4749 }
4750 assert(!session->current_trace_chunk);
4751 ret = session_set_trace_chunk(session, snapshot_trace_chunk, NULL);
4752 lttng_trace_chunk_put(snapshot_trace_chunk);
4753 snapshot_trace_chunk = NULL;
4754 if (ret) {
4755 ERR("Failed to set temporary trace chunk to record a snapshot of session \"%s\"",
4756 session->name);
4757 ret_code = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
4758 goto error;
4759 }
4760
4761 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4762 snapshot_output->max_size);
4763 if (nb_packets_per_stream < 0) {
4764 ret_code = LTTNG_ERR_MAX_SIZE_INVALID;
4765 goto error_close_trace_chunk;
4766 }
4767
4768 if (session->kernel_session) {
4769 ret_code = record_kernel_snapshot(session->kernel_session,
4770 snapshot_kernel_consumer_output, session,
4771 wait, nb_packets_per_stream);
4772 if (ret_code != LTTNG_OK) {
4773 goto error_close_trace_chunk;
4774 }
4775 }
4776
4777 if (session->ust_session) {
4778 ret_code = record_ust_snapshot(session->ust_session,
4779 snapshot_ust_consumer_output, session,
4780 wait, nb_packets_per_stream);
4781 if (ret_code != LTTNG_OK) {
4782 goto error_close_trace_chunk;
4783 }
4784 }
4785
4786 error_close_trace_chunk:
4787 if (session_set_trace_chunk(session, NULL, &snapshot_trace_chunk)) {
4788 ERR("Failed to release the current trace chunk of session \"%s\"",
4789 session->name);
4790 ret_code = LTTNG_ERR_UNK;
4791 }
4792
4793 if (session_close_trace_chunk(session, snapshot_trace_chunk,
4794 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION, NULL)) {
4795 /*
4796 * Don't goto end; make sure the chunk is closed for the session
4797 * to allow future snapshots.
4798 */
4799 ERR("Failed to close snapshot trace chunk of session \"%s\"",
4800 session->name);
4801 ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
4802 }
4803 error:
4804 if (original_ust_consumer_output) {
4805 session->ust_session->consumer = original_ust_consumer_output;
4806 }
4807 if (original_kernel_consumer_output) {
4808 session->kernel_session->consumer =
4809 original_kernel_consumer_output;
4810 }
4811 consumer_output_put(snapshot_ust_consumer_output);
4812 consumer_output_put(snapshot_kernel_consumer_output);
4813 return ret_code;
4814 }
4815
4816 /*
4817 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
4818 *
4819 * The wait parameter is ignored so this call always wait for the snapshot to
4820 * complete before returning.
4821 *
4822 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4823 */
4824 int cmd_snapshot_record(struct ltt_session *session,
4825 const struct lttng_snapshot_output *output, int wait)
4826 {
4827 enum lttng_error_code cmd_ret = LTTNG_OK;
4828 int ret;
4829 unsigned int snapshot_success = 0;
4830 char datetime[16];
4831 struct snapshot_output *tmp_output = NULL;
4832
4833 assert(session);
4834 assert(output);
4835
4836 DBG("Cmd snapshot record for session %s", session->name);
4837
4838 /* Get the datetime for the snapshot output directory. */
4839 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
4840 sizeof(datetime));
4841 if (!ret) {
4842 cmd_ret = LTTNG_ERR_INVALID;
4843 goto error;
4844 }
4845
4846 /*
4847 * Permission denied to create an output if the session is not
4848 * set in no output mode.
4849 */
4850 if (session->output_traces) {
4851 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4852 goto error;
4853 }
4854
4855 /* The session needs to be started at least once. */
4856 if (!session->has_been_started) {
4857 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4858 goto error;
4859 }
4860
4861 /* Use temporary output for the session. */
4862 if (*output->ctrl_url != '\0') {
4863 tmp_output = snapshot_output_alloc();
4864 if (!tmp_output) {
4865 cmd_ret = LTTNG_ERR_NOMEM;
4866 goto error;
4867 }
4868
4869 ret = snapshot_output_init(session, output->max_size,
4870 output->name,
4871 output->ctrl_url, output->data_url,
4872 session->consumer,
4873 tmp_output, NULL);
4874 if (ret < 0) {
4875 if (ret == -ENOMEM) {
4876 cmd_ret = LTTNG_ERR_NOMEM;
4877 } else {
4878 cmd_ret = LTTNG_ERR_INVALID;
4879 }
4880 goto error;
4881 }
4882 /* Use the global session count for the temporary snapshot. */
4883 tmp_output->nb_snapshot = session->snapshot.nb_snapshot;
4884
4885 /* Use the global datetime */
4886 memcpy(tmp_output->datetime, datetime, sizeof(datetime));
4887 cmd_ret = snapshot_record(session, tmp_output, wait);
4888 if (cmd_ret != LTTNG_OK) {
4889 goto error;
4890 }
4891 snapshot_success = 1;
4892 } else {
4893 struct snapshot_output *sout;
4894 struct lttng_ht_iter iter;
4895
4896 rcu_read_lock();
4897 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
4898 &iter.iter, sout, node.node) {
4899 struct snapshot_output output_copy;
4900
4901 /*
4902 * Make a local copy of the output and override output
4903 * parameters with those provided as part of the
4904 * command.
4905 */
4906 memcpy(&output_copy, sout, sizeof(output_copy));
4907
4908 if (output->max_size != (uint64_t) -1ULL) {
4909 output_copy.max_size = output->max_size;
4910 }
4911
4912 output_copy.nb_snapshot = session->snapshot.nb_snapshot;
4913 memcpy(output_copy.datetime, datetime,
4914 sizeof(datetime));
4915
4916 /* Use temporary name. */
4917 if (*output->name != '\0') {
4918 if (lttng_strncpy(output_copy.name,
4919 output->name,
4920 sizeof(output_copy.name))) {
4921 cmd_ret = LTTNG_ERR_INVALID;
4922 rcu_read_unlock();
4923 goto error;
4924 }
4925 }
4926
4927 cmd_ret = snapshot_record(session, &output_copy, wait);
4928 if (cmd_ret != LTTNG_OK) {
4929 rcu_read_unlock();
4930 goto error;
4931 }
4932 snapshot_success = 1;
4933 }
4934 rcu_read_unlock();
4935 }
4936
4937 if (snapshot_success) {
4938 session->snapshot.nb_snapshot++;
4939 } else {
4940 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
4941 }
4942
4943 error:
4944 if (tmp_output) {
4945 snapshot_output_destroy(tmp_output);
4946 }
4947 return cmd_ret;
4948 }
4949
4950 /*
4951 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
4952 */
4953 int cmd_set_session_shm_path(struct ltt_session *session,
4954 const char *shm_path)
4955 {
4956 /* Safety net */
4957 assert(session);
4958
4959 /*
4960 * Can only set shm path before session is started.
4961 */
4962 if (session->has_been_started) {
4963 return LTTNG_ERR_SESSION_STARTED;
4964 }
4965
4966 strncpy(session->shm_path, shm_path,
4967 sizeof(session->shm_path));
4968 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
4969
4970 return 0;
4971 }
4972
4973 /*
4974 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
4975 *
4976 * Ask the consumer to rotate the session output directory.
4977 * The session lock must be held.
4978 *
4979 * Returns LTTNG_OK on success or else a negative LTTng error code.
4980 */
4981 int cmd_rotate_session(struct ltt_session *session,
4982 struct lttng_rotate_session_return *rotate_return,
4983 bool quiet_rotation,
4984 enum lttng_trace_chunk_command_type command)
4985 {
4986 int ret;
4987 uint64_t ongoing_rotation_chunk_id;
4988 enum lttng_error_code cmd_ret = LTTNG_OK;
4989 struct lttng_trace_chunk *chunk_being_archived = NULL;
4990 struct lttng_trace_chunk *new_trace_chunk = NULL;
4991 enum lttng_trace_chunk_status chunk_status;
4992 bool failed_to_rotate = false;
4993 enum lttng_error_code rotation_fail_code = LTTNG_OK;
4994
4995 assert(session);
4996
4997 if (!session->has_been_started) {
4998 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4999 goto end;
5000 }
5001
5002 /*
5003 * Explicit rotation is not supported for live sessions.
5004 * However, live sessions can perform a quiet rotation on
5005 * destroy.
5006 * Rotation is not supported for snapshot traces (no output).
5007 */
5008 if ((!quiet_rotation && session->live_timer) ||
5009 !session->output_traces) {
5010 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5011 goto end;
5012 }
5013
5014 /* Unsupported feature in lttng-relayd before 2.11. */
5015 if (!quiet_rotation && session->consumer->type == CONSUMER_DST_NET &&
5016 (session->consumer->relay_major_version == 2 &&
5017 session->consumer->relay_minor_version < 11)) {
5018 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
5019 goto end;
5020 }
5021
5022 /* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
5023 if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
5024 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
5025 goto end;
5026 }
5027
5028 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
5029 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
5030 session->name);
5031 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
5032 goto end;
5033 }
5034
5035 /*
5036 * After a stop, we only allow one rotation to occur, the other ones are
5037 * useless until a new start.
5038 */
5039 if (session->rotated_after_last_stop) {
5040 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
5041 session->name);
5042 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
5043 goto end;
5044 }
5045
5046 /*
5047 * After a stop followed by a clear, disallow following rotations a they would
5048 * generate empty chunks.
5049 */
5050 if (session->cleared_after_last_stop) {
5051 DBG("Session \"%s\" was already cleared after stop, refusing rotation",
5052 session->name);
5053 cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
5054 goto end;
5055 }
5056
5057 if (session->active) {
5058 new_trace_chunk = session_create_new_trace_chunk(session, NULL,
5059 NULL, NULL);
5060 if (!new_trace_chunk) {
5061 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
5062 goto error;
5063 }
5064 }
5065
5066 /*
5067 * The current trace chunk becomes the chunk being archived.
5068 *
5069 * After this point, "chunk_being_archived" must absolutely
5070 * be closed on the consumer(s), otherwise it will never be
5071 * cleaned-up, which will result in a leak.
5072 */
5073 ret = session_set_trace_chunk(session, new_trace_chunk,
5074 &chunk_being_archived);
5075 if (ret) {
5076 cmd_ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
5077 goto error;
5078 }
5079
5080 if (session->kernel_session) {
5081 cmd_ret = kernel_rotate_session(session);
5082 if (cmd_ret != LTTNG_OK) {
5083 failed_to_rotate = true;
5084 rotation_fail_code = cmd_ret;
5085 }
5086 }
5087 if (session->ust_session) {
5088 cmd_ret = ust_app_rotate_session(session);
5089 if (cmd_ret != LTTNG_OK) {
5090 failed_to_rotate = true;
5091 rotation_fail_code = cmd_ret;
5092 }
5093 }
5094
5095 if (!session->active) {
5096 session->rotated_after_last_stop = true;
5097 }
5098
5099 if (!chunk_being_archived) {
5100 DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
5101 session->name);
5102 if (failed_to_rotate) {
5103 cmd_ret = rotation_fail_code;
5104 goto error;
5105 }
5106 cmd_ret = LTTNG_OK;
5107 goto end;
5108 }
5109
5110 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
5111 chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
5112 &ongoing_rotation_chunk_id);
5113 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5114
5115 ret = session_close_trace_chunk(session, chunk_being_archived,
5116 command, session->last_chunk_path);
5117 if (ret) {
5118 cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
5119 goto error;
5120 }
5121
5122 if (failed_to_rotate) {
5123 cmd_ret = rotation_fail_code;
5124 goto error;
5125 }
5126
5127 session->quiet_rotation = quiet_rotation;
5128 ret = timer_session_rotation_pending_check_start(session,
5129 DEFAULT_ROTATE_PENDING_TIMER);
5130 if (ret) {
5131 cmd_ret = LTTNG_ERR_UNK;
5132 goto error;
5133 }
5134
5135 if (rotate_return) {
5136 rotate_return->rotation_id = ongoing_rotation_chunk_id;
5137 }
5138
5139 session->chunk_being_archived = chunk_being_archived;
5140 chunk_being_archived = NULL;
5141 if (!quiet_rotation) {
5142 ret = notification_thread_command_session_rotation_ongoing(
5143 notification_thread_handle,
5144 session->name, session->uid, session->gid,
5145 ongoing_rotation_chunk_id);
5146 if (ret != LTTNG_OK) {
5147 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
5148 session->name);
5149 cmd_ret = ret;
5150 }
5151 }
5152
5153 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
5154 session->name, ongoing_rotation_chunk_id);
5155 end:
5156 lttng_trace_chunk_put(new_trace_chunk);
5157 lttng_trace_chunk_put(chunk_being_archived);
5158 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
5159 return ret;
5160 error:
5161 if (session_reset_rotation_state(session,
5162 LTTNG_ROTATION_STATE_ERROR)) {
5163 ERR("Failed to reset rotation state of session \"%s\"",
5164 session->name);
5165 }
5166 goto end;
5167 }
5168
5169 /*
5170 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
5171 *
5172 * Check if the session has finished its rotation.
5173 *
5174 * Return LTTNG_OK on success or else an LTTNG_ERR code.
5175 */
5176 int cmd_rotate_get_info(struct ltt_session *session,
5177 struct lttng_rotation_get_info_return *info_return,
5178 uint64_t rotation_id)
5179 {
5180 enum lttng_error_code cmd_ret = LTTNG_OK;
5181 enum lttng_rotation_state rotation_state;
5182
5183 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
5184 session->most_recent_chunk_id.value);
5185
5186 if (session->chunk_being_archived) {
5187 enum lttng_trace_chunk_status chunk_status;
5188 uint64_t chunk_id;
5189
5190 chunk_status = lttng_trace_chunk_get_id(
5191 session->chunk_being_archived,
5192 &chunk_id);
5193 assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
5194
5195 rotation_state = rotation_id == chunk_id ?
5196 LTTNG_ROTATION_STATE_ONGOING :
5197 LTTNG_ROTATION_STATE_EXPIRED;
5198 } else {
5199 if (session->last_archived_chunk_id.is_set &&
5200 rotation_id != session->last_archived_chunk_id.value) {
5201 rotation_state = LTTNG_ROTATION_STATE_EXPIRED;
5202 } else {
5203 rotation_state = session->rotation_state;
5204 }
5205 }
5206
5207 switch (rotation_state) {
5208 case LTTNG_ROTATION_STATE_NO_ROTATION:
5209 DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
5210 session->name);
5211 goto end;
5212 case LTTNG_ROTATION_STATE_EXPIRED:
5213 DBG("Reporting that the rotation state of rotation id %" PRIu64 " of session \"%s\" has expired",
5214 rotation_id, session->name);
5215 break;
5216 case LTTNG_ROTATION_STATE_ONGOING:
5217 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is still pending",
5218 rotation_id, session->name);
5219 break;
5220 case LTTNG_ROTATION_STATE_COMPLETED:
5221 {
5222 int fmt_ret;
5223 char *chunk_path;
5224 char *current_tracing_path_reply;
5225 size_t current_tracing_path_reply_len;
5226
5227 DBG("Reporting that rotation id %" PRIu64 " of session \"%s\" is completed",
5228 rotation_id, session->name);
5229
5230 switch (session_get_consumer_destination_type(session)) {
5231 case CONSUMER_DST_LOCAL:
5232 current_tracing_path_reply =
5233 info_return->location.local.absolute_path;
5234 current_tracing_path_reply_len =
5235 sizeof(info_return->location.local.absolute_path);
5236 info_return->location_type =
5237 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
5238 fmt_ret = asprintf(&chunk_path,
5239 "%s/" DEFAULT_ARCHIVED_TRACE_CHUNKS_DIRECTORY "/%s",
5240 session_get_base_path(session),
5241 session->last_archived_chunk_name);
5242 if (fmt_ret == -1) {
5243 PERROR("Failed to format the path of the last archived trace chunk");
5244 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5245 cmd_ret = LTTNG_ERR_UNK;
5246 goto end;
5247 }
5248 break;
5249 case CONSUMER_DST_NET:
5250 {
5251 uint16_t ctrl_port, data_port;
5252
5253 current_tracing_path_reply =
5254 info_return->location.relay.relative_path;
5255 current_tracing_path_reply_len =
5256 sizeof(info_return->location.relay.relative_path);
5257 /* Currently the only supported relay protocol. */
5258 info_return->location.relay.protocol =
5259 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
5260
5261 fmt_ret = lttng_strncpy(info_return->location.relay.host,
5262 session_get_net_consumer_hostname(session),
5263 sizeof(info_return->location.relay.host));
5264 if (fmt_ret) {
5265 ERR("Failed to copy host name to rotate_get_info reply");
5266 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5267 cmd_ret = LTTNG_ERR_SET_URL;
5268 goto end;
5269 }
5270
5271 session_get_net_consumer_ports(session, &ctrl_port, &data_port);
5272 info_return->location.relay.ports.control = ctrl_port;
5273 info_return->location.relay.ports.data = data_port;
5274 info_return->location_type =
5275 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
5276 chunk_path = strdup(session->last_chunk_path);
5277 if (!chunk_path) {
5278 ERR("Failed to allocate the path of the last archived trace chunk");
5279 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5280 cmd_ret = LTTNG_ERR_UNK;
5281 goto end;
5282 }
5283 break;
5284 }
5285 default:
5286 abort();
5287 }
5288
5289 fmt_ret = lttng_strncpy(current_tracing_path_reply,
5290 chunk_path, current_tracing_path_reply_len);
5291 free(chunk_path);
5292 if (fmt_ret) {
5293 ERR("Failed to copy path of the last archived trace chunk to rotate_get_info reply");
5294 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
5295 cmd_ret = LTTNG_ERR_UNK;
5296 goto end;
5297 }
5298
5299 break;
5300 }
5301 case LTTNG_ROTATION_STATE_ERROR:
5302 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session \"%s\"",
5303 rotation_id, session->name);
5304 break;
5305 default:
5306 abort();
5307 }
5308
5309 cmd_ret = LTTNG_OK;
5310 end:
5311 info_return->status = (int32_t) rotation_state;
5312 return cmd_ret;
5313 }
5314
5315 /*
5316 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
5317 *
5318 * Configure the automatic rotation parameters.
5319 * 'activate' to true means activate the rotation schedule type with 'new_value'.
5320 * 'activate' to false means deactivate the rotation schedule and validate that
5321 * 'new_value' has the same value as the currently active value.
5322 *
5323 * Return 0 on success or else a positive LTTNG_ERR code.
5324 */
5325 int cmd_rotation_set_schedule(struct ltt_session *session,
5326 bool activate, enum lttng_rotation_schedule_type schedule_type,
5327 uint64_t new_value,
5328 struct notification_thread_handle *notification_thread_handle)
5329 {
5330 int ret;
5331 uint64_t *parameter_value;
5332
5333 assert(session);
5334
5335 DBG("Cmd rotate set schedule session %s", session->name);
5336
5337 if (session->live_timer || !session->output_traces) {
5338 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
5339 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
5340 goto end;
5341 }
5342
5343 switch (schedule_type) {
5344 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5345 parameter_value = &session->rotate_size;
5346 break;
5347 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5348 parameter_value = &session->rotate_timer_period;
5349 if (new_value >= UINT_MAX) {
5350 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
5351 new_value, UINT_MAX);
5352 ret = LTTNG_ERR_INVALID;
5353 goto end;
5354 }
5355 break;
5356 default:
5357 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
5358 ret = LTTNG_ERR_INVALID;
5359 goto end;
5360 }
5361
5362 /* Improper use of the API. */
5363 if (new_value == -1ULL) {
5364 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
5365 ret = LTTNG_ERR_INVALID;
5366 goto end;
5367 }
5368
5369 /*
5370 * As indicated in struct ltt_session's comments, a value of == 0 means
5371 * this schedule rotation type is not in use.
5372 *
5373 * Reject the command if we were asked to activate a schedule that was
5374 * already active.
5375 */
5376 if (activate && *parameter_value != 0) {
5377 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
5378 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
5379 goto end;
5380 }
5381
5382 /*
5383 * Reject the command if we were asked to deactivate a schedule that was
5384 * not active.
5385 */
5386 if (!activate && *parameter_value == 0) {
5387 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
5388 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5389 goto end;
5390 }
5391
5392 /*
5393 * Reject the command if we were asked to deactivate a schedule that
5394 * doesn't exist.
5395 */
5396 if (!activate && *parameter_value != new_value) {
5397 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
5398 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
5399 goto end;
5400 }
5401
5402 *parameter_value = activate ? new_value : 0;
5403
5404 switch (schedule_type) {
5405 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
5406 if (activate && session->active) {
5407 /*
5408 * Only start the timer if the session is active,
5409 * otherwise it will be started when the session starts.
5410 */
5411 ret = timer_session_rotation_schedule_timer_start(
5412 session, new_value);
5413 if (ret) {
5414 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
5415 ret = LTTNG_ERR_UNK;
5416 goto end;
5417 }
5418 } else {
5419 ret = timer_session_rotation_schedule_timer_stop(
5420 session);
5421 if (ret) {
5422 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
5423 ret = LTTNG_ERR_UNK;
5424 goto end;
5425 }
5426 }
5427 break;
5428 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
5429 if (activate) {
5430 ret = subscribe_session_consumed_size_rotation(session,
5431 new_value, notification_thread_handle);
5432 if (ret) {
5433 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
5434 ret = LTTNG_ERR_UNK;
5435 goto end;
5436 }
5437 } else {
5438 ret = unsubscribe_session_consumed_size_rotation(session,
5439 notification_thread_handle);
5440 if (ret) {
5441 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
5442 ret = LTTNG_ERR_UNK;
5443 goto end;
5444 }
5445
5446 }
5447 break;
5448 default:
5449 /* Would have been caught before. */
5450 abort();
5451 }
5452
5453 ret = LTTNG_OK;
5454
5455 goto end;
5456
5457 end:
5458 return ret;
5459 }
5460
5461 /* Wait for a given path to be removed before continuing. */
5462 static enum lttng_error_code wait_on_path(void *path_data)
5463 {
5464 const char *shm_path = path_data;
5465
5466 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
5467 shm_path);
5468 while (true) {
5469 int ret;
5470 struct stat st;
5471
5472 ret = stat(shm_path, &st);
5473 if (ret) {
5474 if (errno != ENOENT) {
5475 PERROR("stat() returned an error while checking for the existence of the shm path");
5476 } else {
5477 DBG("shm path no longer exists, completing the destruction of session");
5478 }
5479 break;
5480 } else {
5481 if (!S_ISDIR(st.st_mode)) {
5482 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5483 shm_path);
5484 break;
5485 }
5486 }
5487 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5488 }
5489 return LTTNG_OK;
5490 }
5491
5492 /*
5493 * Returns a pointer to a handler to run on completion of a command.
5494 * Returns NULL if no handler has to be run for the last command executed.
5495 */
5496 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
5497 {
5498 struct cmd_completion_handler *handler = current_completion_handler;
5499
5500 current_completion_handler = NULL;
5501 return handler;
5502 }
5503
5504 /*
5505 * Init command subsystem.
5506 */
5507 void cmd_init(void)
5508 {
5509 /*
5510 * Set network sequence index to 1 for streams to match a relayd
5511 * socket on the consumer side.
5512 */
5513 pthread_mutex_lock(&relayd_net_seq_idx_lock);
5514 relayd_net_seq_idx = 1;
5515 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
5516
5517 DBG("Command subsystem initialized");
5518 }
LTTng tools - Deliverables
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