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Move LTTng-UST buffer ownership from application to consumer
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <assert.h>
20 #include <urcu/list.h>
21 #include <urcu/uatomic.h>
22
23 #include <common/defaults.h>
24 #include <common/common.h>
25 #include <common/sessiond-comm/sessiond-comm.h>
26 #include <common/relayd/relayd.h>
27
28 #include "channel.h"
29 #include "consumer.h"
30 #include "event.h"
31 #include "kernel.h"
32 #include "kernel-consumer.h"
33 #include "lttng-sessiond.h"
34 #include "utils.h"
35
36 #include "cmd.h"
37
38 /*
39 * Used to keep a unique index for each relayd socket created where this value
40 * is associated with streams on the consumer so it can match the right relayd
41 * to send to.
42 *
43 * This value should be incremented atomically for safety purposes and future
44 * possible concurrent access.
45 */
46 static unsigned int relayd_net_seq_idx;
47
48 /*
49 * Create a session path used by list_lttng_sessions for the case that the
50 * session consumer is on the network.
51 */
52 static int build_network_session_path(char *dst, size_t size,
53 struct ltt_session *session)
54 {
55 int ret, kdata_port, udata_port;
56 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
57 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
58
59 assert(session);
60 assert(dst);
61
62 memset(tmp_urls, 0, sizeof(tmp_urls));
63 memset(tmp_uurl, 0, sizeof(tmp_uurl));
64
65 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
66
67 if (session->kernel_session && session->kernel_session->consumer) {
68 kuri = &session->kernel_session->consumer->dst.net.control;
69 kdata_port = session->kernel_session->consumer->dst.net.data.port;
70 }
71
72 if (session->ust_session && session->ust_session->consumer) {
73 uuri = &session->ust_session->consumer->dst.net.control;
74 udata_port = session->ust_session->consumer->dst.net.data.port;
75 }
76
77 if (uuri == NULL && kuri == NULL) {
78 uri = &session->consumer->dst.net.control;
79 kdata_port = session->consumer->dst.net.data.port;
80 } else if (kuri && uuri) {
81 ret = uri_compare(kuri, uuri);
82 if (ret) {
83 /* Not Equal */
84 uri = kuri;
85 /* Build uuri URL string */
86 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
87 if (ret < 0) {
88 goto error;
89 }
90 } else {
91 uri = kuri;
92 }
93 } else if (kuri && uuri == NULL) {
94 uri = kuri;
95 } else if (uuri && kuri == NULL) {
96 uri = uuri;
97 }
98
99 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
100 if (ret < 0) {
101 goto error;
102 }
103
104 /*
105 * Do we have a UST url set. If yes, this means we have both kernel and UST
106 * to print.
107 */
108 if (*tmp_uurl != '\0') {
109 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
110 tmp_urls, kdata_port, tmp_uurl, udata_port);
111 } else {
112 int dport;
113 if (kuri) {
114 dport = kdata_port;
115 } else {
116 /* No kernel URI, use the UST port. */
117 dport = udata_port;
118 }
119 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
120 }
121
122 error:
123 return ret;
124 }
125
126 /*
127 * Fill lttng_channel array of all channels.
128 */
129 static void list_lttng_channels(int domain, struct ltt_session *session,
130 struct lttng_channel *channels)
131 {
132 int i = 0;
133 struct ltt_kernel_channel *kchan;
134
135 DBG("Listing channels for session %s", session->name);
136
137 switch (domain) {
138 case LTTNG_DOMAIN_KERNEL:
139 /* Kernel channels */
140 if (session->kernel_session != NULL) {
141 cds_list_for_each_entry(kchan,
142 &session->kernel_session->channel_list.head, list) {
143 /* Copy lttng_channel struct to array */
144 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
145 channels[i].enabled = kchan->enabled;
146 i++;
147 }
148 }
149 break;
150 case LTTNG_DOMAIN_UST:
151 {
152 struct lttng_ht_iter iter;
153 struct ltt_ust_channel *uchan;
154
155 rcu_read_lock();
156 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
157 &iter.iter, uchan, node.node) {
158 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
159 channels[i].attr.overwrite = uchan->attr.overwrite;
160 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
161 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
162 channels[i].attr.switch_timer_interval =
163 uchan->attr.switch_timer_interval;
164 channels[i].attr.read_timer_interval =
165 uchan->attr.read_timer_interval;
166 channels[i].enabled = uchan->enabled;
167 switch (uchan->attr.output) {
168 case LTTNG_UST_MMAP:
169 default:
170 channels[i].attr.output = LTTNG_EVENT_MMAP;
171 break;
172 }
173 i++;
174 }
175 rcu_read_unlock();
176 break;
177 }
178 default:
179 break;
180 }
181 }
182
183 /*
184 * Create a list of ust global domain events.
185 */
186 static int list_lttng_ust_global_events(char *channel_name,
187 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
188 {
189 int i = 0, ret = 0;
190 unsigned int nb_event = 0;
191 struct lttng_ht_iter iter;
192 struct lttng_ht_node_str *node;
193 struct ltt_ust_channel *uchan;
194 struct ltt_ust_event *uevent;
195 struct lttng_event *tmp;
196
197 DBG("Listing UST global events for channel %s", channel_name);
198
199 rcu_read_lock();
200
201 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
202 node = lttng_ht_iter_get_node_str(&iter);
203 if (node == NULL) {
204 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
205 goto error;
206 }
207
208 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
209
210 nb_event += lttng_ht_get_count(uchan->events);
211
212 if (nb_event == 0) {
213 ret = nb_event;
214 goto error;
215 }
216
217 DBG3("Listing UST global %d events", nb_event);
218
219 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
220 if (tmp == NULL) {
221 ret = LTTNG_ERR_FATAL;
222 goto error;
223 }
224
225 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
226 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
227 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
228 tmp[i].enabled = uevent->enabled;
229
230 switch (uevent->attr.instrumentation) {
231 case LTTNG_UST_TRACEPOINT:
232 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
233 break;
234 case LTTNG_UST_PROBE:
235 tmp[i].type = LTTNG_EVENT_PROBE;
236 break;
237 case LTTNG_UST_FUNCTION:
238 tmp[i].type = LTTNG_EVENT_FUNCTION;
239 break;
240 }
241
242 tmp[i].loglevel = uevent->attr.loglevel;
243 switch (uevent->attr.loglevel_type) {
244 case LTTNG_UST_LOGLEVEL_ALL:
245 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
246 break;
247 case LTTNG_UST_LOGLEVEL_RANGE:
248 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
249 break;
250 case LTTNG_UST_LOGLEVEL_SINGLE:
251 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
252 break;
253 }
254 if (uevent->filter) {
255 tmp[i].filter = 1;
256 }
257 i++;
258 }
259
260 ret = nb_event;
261 *events = tmp;
262
263 error:
264 rcu_read_unlock();
265 return ret;
266 }
267
268 /*
269 * Fill lttng_event array of all kernel events in the channel.
270 */
271 static int list_lttng_kernel_events(char *channel_name,
272 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
273 {
274 int i = 0, ret;
275 unsigned int nb_event;
276 struct ltt_kernel_event *event;
277 struct ltt_kernel_channel *kchan;
278
279 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
280 if (kchan == NULL) {
281 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
282 goto error;
283 }
284
285 nb_event = kchan->event_count;
286
287 DBG("Listing events for channel %s", kchan->channel->name);
288
289 if (nb_event == 0) {
290 goto end;
291 }
292
293 *events = zmalloc(nb_event * sizeof(struct lttng_event));
294 if (*events == NULL) {
295 ret = LTTNG_ERR_FATAL;
296 goto error;
297 }
298
299 /* Kernel channels */
300 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
301 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
302 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
303 (*events)[i].enabled = event->enabled;
304
305 switch (event->event->instrumentation) {
306 case LTTNG_KERNEL_TRACEPOINT:
307 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
308 break;
309 case LTTNG_KERNEL_KPROBE:
310 case LTTNG_KERNEL_KRETPROBE:
311 (*events)[i].type = LTTNG_EVENT_PROBE;
312 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
313 sizeof(struct lttng_kernel_kprobe));
314 break;
315 case LTTNG_KERNEL_FUNCTION:
316 (*events)[i].type = LTTNG_EVENT_FUNCTION;
317 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
318 sizeof(struct lttng_kernel_function));
319 break;
320 case LTTNG_KERNEL_NOOP:
321 (*events)[i].type = LTTNG_EVENT_NOOP;
322 break;
323 case LTTNG_KERNEL_SYSCALL:
324 (*events)[i].type = LTTNG_EVENT_SYSCALL;
325 break;
326 case LTTNG_KERNEL_ALL:
327 assert(0);
328 break;
329 }
330 i++;
331 }
332
333 end:
334 return nb_event;
335
336 error:
337 /* Negate the error code to differentiate the size from an error */
338 return -ret;
339 }
340
341 /*
342 * Add URI so the consumer output object. Set the correct path depending on the
343 * domain adding the default trace directory.
344 */
345 static int add_uri_to_consumer(struct consumer_output *consumer,
346 struct lttng_uri *uri, int domain, const char *session_name)
347 {
348 int ret = LTTNG_OK;
349 const char *default_trace_dir;
350
351 assert(uri);
352
353 if (consumer == NULL) {
354 DBG("No consumer detected. Don't add URI. Stopping.");
355 ret = LTTNG_ERR_NO_CONSUMER;
356 goto error;
357 }
358
359 switch (domain) {
360 case LTTNG_DOMAIN_KERNEL:
361 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
362 break;
363 case LTTNG_DOMAIN_UST:
364 default_trace_dir = DEFAULT_UST_TRACE_DIR;
365 break;
366 default:
367 /*
368 * This case is possible is we try to add the URI to the global tracing
369 * session consumer object which in this case there is no subdir.
370 */
371 default_trace_dir = "";
372 }
373
374 switch (uri->dtype) {
375 case LTTNG_DST_IPV4:
376 case LTTNG_DST_IPV6:
377 DBG2("Setting network URI to consumer");
378
379 consumer->type = CONSUMER_DST_NET;
380
381 /* Set URI into consumer output object */
382 ret = consumer_set_network_uri(consumer, uri);
383 if (ret < 0) {
384 ret = LTTNG_ERR_FATAL;
385 goto error;
386 } else if (ret == 1) {
387 /*
388 * URI was the same in the consumer so we do not append the subdir
389 * again so to not duplicate output dir.
390 */
391 goto error;
392 }
393
394 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
395 ret = consumer_set_subdir(consumer, session_name);
396 if (ret < 0) {
397 ret = LTTNG_ERR_FATAL;
398 goto error;
399 }
400 }
401
402 if (uri->stype == LTTNG_STREAM_CONTROL) {
403 /* On a new subdir, reappend the default trace dir. */
404 strncat(consumer->subdir, default_trace_dir,
405 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
406 DBG3("Append domain trace name to subdir %s", consumer->subdir);
407 }
408
409 break;
410 case LTTNG_DST_PATH:
411 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
412 memset(consumer->dst.trace_path, 0,
413 sizeof(consumer->dst.trace_path));
414 strncpy(consumer->dst.trace_path, uri->dst.path,
415 sizeof(consumer->dst.trace_path));
416 /* Append default trace dir */
417 strncat(consumer->dst.trace_path, default_trace_dir,
418 sizeof(consumer->dst.trace_path) -
419 strlen(consumer->dst.trace_path) - 1);
420 /* Flag consumer as local. */
421 consumer->type = CONSUMER_DST_LOCAL;
422 break;
423 }
424
425 error:
426 return ret;
427 }
428
429 /*
430 * Init tracing by creating trace directory and sending fds kernel consumer.
431 */
432 static int init_kernel_tracing(struct ltt_kernel_session *session)
433 {
434 int ret = 0;
435 struct lttng_ht_iter iter;
436 struct consumer_socket *socket;
437
438 assert(session);
439
440 rcu_read_lock();
441
442 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
443 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
444 socket, node.node) {
445 /* Code flow error */
446 assert(socket->fd >= 0);
447
448 pthread_mutex_lock(socket->lock);
449 ret = kernel_consumer_send_session(socket, session);
450 pthread_mutex_unlock(socket->lock);
451 if (ret < 0) {
452 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
453 goto error;
454 }
455 }
456 }
457
458 error:
459 rcu_read_unlock();
460 return ret;
461 }
462
463 /*
464 * Create a socket to the relayd using the URI.
465 *
466 * On success, the relayd_sock pointer is set to the created socket.
467 * Else, it's stays untouched and a lttcomm error code is returned.
468 */
469 static int create_connect_relayd(struct consumer_output *output,
470 const char *session_name, struct lttng_uri *uri,
471 struct lttcomm_sock **relayd_sock)
472 {
473 int ret;
474 struct lttcomm_sock *sock;
475
476 /* Create socket object from URI */
477 sock = lttcomm_alloc_sock_from_uri(uri);
478 if (sock == NULL) {
479 ret = LTTNG_ERR_FATAL;
480 goto error;
481 }
482
483 ret = lttcomm_create_sock(sock);
484 if (ret < 0) {
485 ret = LTTNG_ERR_FATAL;
486 goto error;
487 }
488
489 /*
490 * Connect to relayd so we can proceed with a session creation. This call
491 * can possibly block for an arbitrary amount of time to set the health
492 * state to be in poll execution.
493 */
494 health_poll_entry();
495 ret = relayd_connect(sock);
496 health_poll_exit();
497 if (ret < 0) {
498 ERR("Unable to reach lttng-relayd");
499 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
500 goto free_sock;
501 }
502
503 /* Create socket for control stream. */
504 if (uri->stype == LTTNG_STREAM_CONTROL) {
505 DBG3("Creating relayd stream socket from URI");
506
507 /* Check relayd version */
508 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
509 RELAYD_VERSION_COMM_MINOR);
510 if (ret < 0) {
511 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
512 goto close_sock;
513 }
514 } else if (uri->stype == LTTNG_STREAM_DATA) {
515 DBG3("Creating relayd data socket from URI");
516 } else {
517 /* Command is not valid */
518 ERR("Relayd invalid stream type: %d", uri->stype);
519 ret = LTTNG_ERR_INVALID;
520 goto close_sock;
521 }
522
523 *relayd_sock = sock;
524
525 return LTTNG_OK;
526
527 close_sock:
528 if (sock) {
529 (void) relayd_close(sock);
530 }
531 free_sock:
532 if (sock) {
533 lttcomm_destroy_sock(sock);
534 }
535 error:
536 return ret;
537 }
538
539 /*
540 * Connect to the relayd using URI and send the socket to the right consumer.
541 */
542 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
543 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
544 struct consumer_socket *consumer_sock)
545 {
546 int ret;
547 struct lttcomm_sock *sock = NULL;
548
549 /* Connect to relayd and make version check if uri is the control. */
550 ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
551 if (ret != LTTNG_OK) {
552 goto close_sock;
553 }
554
555 /* If the control socket is connected, network session is ready */
556 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
557 session->net_handle = 1;
558 }
559
560 /* Set the network sequence index if not set. */
561 if (consumer->net_seq_index == -1) {
562 /*
563 * Increment net_seq_idx because we are about to transfer the
564 * new relayd socket to the consumer.
565 */
566 uatomic_inc(&relayd_net_seq_idx);
567 /* Assign unique key so the consumer can match streams */
568 uatomic_set(&consumer->net_seq_index,
569 uatomic_read(&relayd_net_seq_idx));
570 }
571
572 /* Send relayd socket to consumer. */
573 ret = consumer_send_relayd_socket(consumer_sock, sock,
574 consumer, relayd_uri->stype, session->id);
575 if (ret < 0) {
576 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
577 goto close_sock;
578 }
579
580 /* Flag that the corresponding socket was sent. */
581 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
582 consumer_sock->control_sock_sent = 1;
583 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
584 consumer_sock->data_sock_sent = 1;
585 }
586
587 ret = LTTNG_OK;
588
589 /*
590 * Close socket which was dup on the consumer side. The session daemon does
591 * NOT keep track of the relayd socket(s) once transfer to the consumer.
592 */
593
594 close_sock:
595 if (sock) {
596 (void) relayd_close(sock);
597 lttcomm_destroy_sock(sock);
598 }
599
600 if (ret != LTTNG_OK) {
601 /*
602 * On error, nullify the consumer sequence index so streams are not
603 * associated with it once sent to the consumer.
604 */
605 uatomic_set(&consumer->net_seq_index, -1);
606 }
607
608 return ret;
609 }
610
611 /*
612 * Send both relayd sockets to a specific consumer and domain. This is a
613 * helper function to facilitate sending the information to the consumer for a
614 * session.
615 */
616 static int send_consumer_relayd_sockets(int domain,
617 struct ltt_session *session, struct consumer_output *consumer,
618 struct consumer_socket *sock)
619 {
620 int ret = LTTNG_OK;
621
622 assert(session);
623 assert(consumer);
624
625 /* Sending control relayd socket. */
626 if (!sock->control_sock_sent) {
627 ret = send_consumer_relayd_socket(domain, session,
628 &consumer->dst.net.control, consumer, sock);
629 if (ret != LTTNG_OK) {
630 goto error;
631 }
632 }
633
634 /* Sending data relayd socket. */
635 if (!sock->data_sock_sent) {
636 ret = send_consumer_relayd_socket(domain, session,
637 &consumer->dst.net.data, consumer, sock);
638 if (ret != LTTNG_OK) {
639 goto error;
640 }
641 }
642
643 error:
644 return ret;
645 }
646
647 /*
648 * Setup relayd connections for a tracing session. First creates the socket to
649 * the relayd and send them to the right domain consumer. Consumer type MUST be
650 * network.
651 */
652 int cmd_setup_relayd(struct ltt_session *session)
653 {
654 int ret = LTTNG_OK;
655 struct ltt_ust_session *usess;
656 struct ltt_kernel_session *ksess;
657 struct consumer_socket *socket;
658 struct lttng_ht_iter iter;
659
660 assert(session);
661
662 usess = session->ust_session;
663 ksess = session->kernel_session;
664
665 DBG2("Setting relayd for session %s", session->name);
666
667 rcu_read_lock();
668
669 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
670 && usess->consumer->enabled) {
671 /* For each consumer socket, send relayd sockets */
672 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
673 socket, node.node) {
674 /* Code flow error */
675 assert(socket->fd >= 0);
676
677 pthread_mutex_lock(socket->lock);
678 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
679 usess->consumer, socket);
680 pthread_mutex_unlock(socket->lock);
681 if (ret != LTTNG_OK) {
682 goto error;
683 }
684 }
685 }
686
687 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
688 && ksess->consumer->enabled) {
689 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
690 socket, node.node) {
691 /* Code flow error */
692 assert(socket->fd >= 0);
693
694 pthread_mutex_lock(socket->lock);
695 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
696 ksess->consumer, socket);
697 pthread_mutex_unlock(socket->lock);
698 if (ret != LTTNG_OK) {
699 goto error;
700 }
701 }
702 }
703
704 error:
705 rcu_read_unlock();
706 return ret;
707 }
708
709 /*
710 * Start a kernel session by opening all necessary streams.
711 */
712 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
713 {
714 int ret;
715 struct ltt_kernel_channel *kchan;
716
717 /* Open kernel metadata */
718 if (ksess->metadata == NULL) {
719 ret = kernel_open_metadata(ksess);
720 if (ret < 0) {
721 ret = LTTNG_ERR_KERN_META_FAIL;
722 goto error;
723 }
724 }
725
726 /* Open kernel metadata stream */
727 if (ksess->metadata_stream_fd < 0) {
728 ret = kernel_open_metadata_stream(ksess);
729 if (ret < 0) {
730 ERR("Kernel create metadata stream failed");
731 ret = LTTNG_ERR_KERN_STREAM_FAIL;
732 goto error;
733 }
734 }
735
736 /* For each channel */
737 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
738 if (kchan->stream_count == 0) {
739 ret = kernel_open_channel_stream(kchan);
740 if (ret < 0) {
741 ret = LTTNG_ERR_KERN_STREAM_FAIL;
742 goto error;
743 }
744 /* Update the stream global counter */
745 ksess->stream_count_global += ret;
746 }
747 }
748
749 /* Setup kernel consumer socket and send fds to it */
750 ret = init_kernel_tracing(ksess);
751 if (ret < 0) {
752 ret = LTTNG_ERR_KERN_START_FAIL;
753 goto error;
754 }
755
756 /* This start the kernel tracing */
757 ret = kernel_start_session(ksess);
758 if (ret < 0) {
759 ret = LTTNG_ERR_KERN_START_FAIL;
760 goto error;
761 }
762
763 /* Quiescent wait after starting trace */
764 kernel_wait_quiescent(kernel_tracer_fd);
765
766 ksess->started = 1;
767
768 ret = LTTNG_OK;
769
770 error:
771 return ret;
772 }
773
774 /*
775 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
776 */
777 int cmd_disable_channel(struct ltt_session *session, int domain,
778 char *channel_name)
779 {
780 int ret;
781 struct ltt_ust_session *usess;
782
783 usess = session->ust_session;
784
785 rcu_read_lock();
786
787 switch (domain) {
788 case LTTNG_DOMAIN_KERNEL:
789 {
790 ret = channel_kernel_disable(session->kernel_session,
791 channel_name);
792 if (ret != LTTNG_OK) {
793 goto error;
794 }
795
796 kernel_wait_quiescent(kernel_tracer_fd);
797 break;
798 }
799 case LTTNG_DOMAIN_UST:
800 {
801 struct ltt_ust_channel *uchan;
802 struct lttng_ht *chan_ht;
803
804 chan_ht = usess->domain_global.channels;
805
806 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
807 if (uchan == NULL) {
808 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
809 goto error;
810 }
811
812 ret = channel_ust_disable(usess, domain, uchan);
813 if (ret != LTTNG_OK) {
814 goto error;
815 }
816 break;
817 }
818 #if 0
819 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
820 case LTTNG_DOMAIN_UST_EXEC_NAME:
821 case LTTNG_DOMAIN_UST_PID:
822 #endif
823 default:
824 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
825 goto error;
826 }
827
828 ret = LTTNG_OK;
829
830 error:
831 rcu_read_unlock();
832 return ret;
833 }
834
835 /*
836 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
837 *
838 * The wpipe arguments is used as a notifier for the kernel thread.
839 */
840 int cmd_enable_channel(struct ltt_session *session,
841 int domain, struct lttng_channel *attr, int wpipe)
842 {
843 int ret;
844 struct ltt_ust_session *usess = session->ust_session;
845 struct lttng_ht *chan_ht;
846
847 assert(session);
848 assert(attr);
849
850 DBG("Enabling channel %s for session %s", attr->name, session->name);
851
852 rcu_read_lock();
853
854 switch (domain) {
855 case LTTNG_DOMAIN_KERNEL:
856 {
857 struct ltt_kernel_channel *kchan;
858
859 kchan = trace_kernel_get_channel_by_name(attr->name,
860 session->kernel_session);
861 if (kchan == NULL) {
862 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
863 } else {
864 ret = channel_kernel_enable(session->kernel_session, kchan);
865 }
866
867 if (ret != LTTNG_OK) {
868 goto error;
869 }
870
871 kernel_wait_quiescent(kernel_tracer_fd);
872
873 /*
874 * If the session was previously started, start as well this newly
875 * created kernel session so the events/channels enabled *after* the
876 * start actually work.
877 */
878 if (session->started && !session->kernel_session->started) {
879 ret = start_kernel_session(session->kernel_session, wpipe);
880 if (ret != LTTNG_OK) {
881 goto error;
882 }
883 }
884 break;
885 }
886 case LTTNG_DOMAIN_UST:
887 {
888 struct ltt_ust_channel *uchan;
889
890 chan_ht = usess->domain_global.channels;
891
892 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
893 if (uchan == NULL) {
894 ret = channel_ust_create(usess, domain, attr);
895 } else {
896 ret = channel_ust_enable(usess, domain, uchan);
897 }
898
899 /* Start the UST session if the session was already started. */
900 if (session->started && !usess->start_trace) {
901 ret = ust_app_start_trace_all(usess);
902 if (ret < 0) {
903 ret = LTTNG_ERR_UST_START_FAIL;
904 goto error;
905 }
906 ret = LTTNG_OK;
907 usess->start_trace = 1;
908 }
909 break;
910 }
911 #if 0
912 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
913 case LTTNG_DOMAIN_UST_EXEC_NAME:
914 case LTTNG_DOMAIN_UST_PID:
915 #endif
916 default:
917 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
918 goto error;
919 }
920
921 error:
922 rcu_read_unlock();
923 return ret;
924 }
925
926
927 /*
928 * Command LTTNG_DISABLE_EVENT processed by the client thread.
929 */
930 int cmd_disable_event(struct ltt_session *session, int domain,
931 char *channel_name, char *event_name)
932 {
933 int ret;
934
935 rcu_read_lock();
936
937 switch (domain) {
938 case LTTNG_DOMAIN_KERNEL:
939 {
940 struct ltt_kernel_channel *kchan;
941 struct ltt_kernel_session *ksess;
942
943 ksess = session->kernel_session;
944
945 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
946 if (kchan == NULL) {
947 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
948 goto error;
949 }
950
951 ret = event_kernel_disable_tracepoint(kchan, event_name);
952 if (ret != LTTNG_OK) {
953 goto error;
954 }
955
956 kernel_wait_quiescent(kernel_tracer_fd);
957 break;
958 }
959 case LTTNG_DOMAIN_UST:
960 {
961 struct ltt_ust_channel *uchan;
962 struct ltt_ust_session *usess;
963
964 usess = session->ust_session;
965
966 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
967 channel_name);
968 if (uchan == NULL) {
969 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
970 goto error;
971 }
972
973 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
974 if (ret != LTTNG_OK) {
975 goto error;
976 }
977
978 DBG3("Disable UST event %s in channel %s completed", event_name,
979 channel_name);
980 break;
981 }
982 #if 0
983 case LTTNG_DOMAIN_UST_EXEC_NAME:
984 case LTTNG_DOMAIN_UST_PID:
985 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
986 #endif
987 default:
988 ret = LTTNG_ERR_UND;
989 goto error;
990 }
991
992 ret = LTTNG_OK;
993
994 error:
995 rcu_read_unlock();
996 return ret;
997 }
998
999 /*
1000 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
1001 */
1002 int cmd_disable_event_all(struct ltt_session *session, int domain,
1003 char *channel_name)
1004 {
1005 int ret;
1006
1007 rcu_read_lock();
1008
1009 switch (domain) {
1010 case LTTNG_DOMAIN_KERNEL:
1011 {
1012 struct ltt_kernel_session *ksess;
1013 struct ltt_kernel_channel *kchan;
1014
1015 ksess = session->kernel_session;
1016
1017 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1018 if (kchan == NULL) {
1019 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1020 goto error;
1021 }
1022
1023 ret = event_kernel_disable_all(kchan);
1024 if (ret != LTTNG_OK) {
1025 goto error;
1026 }
1027
1028 kernel_wait_quiescent(kernel_tracer_fd);
1029 break;
1030 }
1031 case LTTNG_DOMAIN_UST:
1032 {
1033 struct ltt_ust_session *usess;
1034 struct ltt_ust_channel *uchan;
1035
1036 usess = session->ust_session;
1037
1038 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1039 channel_name);
1040 if (uchan == NULL) {
1041 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1042 goto error;
1043 }
1044
1045 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1046 if (ret != 0) {
1047 goto error;
1048 }
1049
1050 DBG3("Disable all UST events in channel %s completed", channel_name);
1051
1052 break;
1053 }
1054 #if 0
1055 case LTTNG_DOMAIN_UST_EXEC_NAME:
1056 case LTTNG_DOMAIN_UST_PID:
1057 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1058 #endif
1059 default:
1060 ret = LTTNG_ERR_UND;
1061 goto error;
1062 }
1063
1064 ret = LTTNG_OK;
1065
1066 error:
1067 rcu_read_unlock();
1068 return ret;
1069 }
1070
1071 /*
1072 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1073 */
1074 int cmd_add_context(struct ltt_session *session, int domain,
1075 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1076 {
1077 int ret;
1078
1079 switch (domain) {
1080 case LTTNG_DOMAIN_KERNEL:
1081 assert(session->kernel_session);
1082
1083 if (session->kernel_session->channel_count == 0) {
1084 /* Create default channel */
1085 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1086 if (ret != LTTNG_OK) {
1087 goto error;
1088 }
1089 }
1090
1091 /* Add kernel context to kernel tracer */
1092 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1093 if (ret != LTTNG_OK) {
1094 goto error;
1095 }
1096 break;
1097 case LTTNG_DOMAIN_UST:
1098 {
1099 struct ltt_ust_session *usess = session->ust_session;
1100 assert(usess);
1101
1102 unsigned int chan_count =
1103 lttng_ht_get_count(usess->domain_global.channels);
1104 if (chan_count == 0) {
1105 struct lttng_channel *attr;
1106 /* Create default channel */
1107 attr = channel_new_default_attr(domain);
1108 if (attr == NULL) {
1109 ret = LTTNG_ERR_FATAL;
1110 goto error;
1111 }
1112
1113 ret = channel_ust_create(usess, domain, attr);
1114 if (ret != LTTNG_OK) {
1115 free(attr);
1116 goto error;
1117 }
1118 free(attr);
1119 }
1120
1121 ret = context_ust_add(usess, domain, ctx, channel_name);
1122 if (ret != LTTNG_OK) {
1123 goto error;
1124 }
1125 break;
1126 }
1127 #if 0
1128 case LTTNG_DOMAIN_UST_EXEC_NAME:
1129 case LTTNG_DOMAIN_UST_PID:
1130 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1131 #endif
1132 default:
1133 ret = LTTNG_ERR_UND;
1134 goto error;
1135 }
1136
1137 ret = LTTNG_OK;
1138
1139 error:
1140 return ret;
1141 }
1142
1143 /*
1144 * Command LTTNG_ENABLE_EVENT processed by the client thread.
1145 */
1146 int cmd_enable_event(struct ltt_session *session, int domain,
1147 char *channel_name, struct lttng_event *event,
1148 struct lttng_filter_bytecode *filter, int wpipe)
1149 {
1150 int ret, channel_created = 0;
1151 struct lttng_channel *attr;
1152
1153 assert(session);
1154 assert(event);
1155 assert(channel_name);
1156
1157 rcu_read_lock();
1158
1159 switch (domain) {
1160 case LTTNG_DOMAIN_KERNEL:
1161 {
1162 struct ltt_kernel_channel *kchan;
1163
1164 kchan = trace_kernel_get_channel_by_name(channel_name,
1165 session->kernel_session);
1166 if (kchan == NULL) {
1167 attr = channel_new_default_attr(domain);
1168 if (attr == NULL) {
1169 ret = LTTNG_ERR_FATAL;
1170 goto error;
1171 }
1172 strncpy(attr->name, channel_name, sizeof(attr->name));
1173
1174 ret = cmd_enable_channel(session, domain, attr, wpipe);
1175 if (ret != LTTNG_OK) {
1176 free(attr);
1177 goto error;
1178 }
1179 free(attr);
1180
1181 channel_created = 1;
1182 }
1183
1184 /* Get the newly created kernel channel pointer */
1185 kchan = trace_kernel_get_channel_by_name(channel_name,
1186 session->kernel_session);
1187 if (kchan == NULL) {
1188 /* This sould not happen... */
1189 ret = LTTNG_ERR_FATAL;
1190 goto error;
1191 }
1192
1193 ret = event_kernel_enable_tracepoint(kchan, event);
1194 if (ret != LTTNG_OK) {
1195 if (channel_created) {
1196 /* Let's not leak a useless channel. */
1197 kernel_destroy_channel(kchan);
1198 }
1199 goto error;
1200 }
1201
1202 kernel_wait_quiescent(kernel_tracer_fd);
1203 break;
1204 }
1205 case LTTNG_DOMAIN_UST:
1206 {
1207 struct ltt_ust_channel *uchan;
1208 struct ltt_ust_session *usess = session->ust_session;
1209
1210 assert(usess);
1211
1212 /* Get channel from global UST domain */
1213 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1214 channel_name);
1215 if (uchan == NULL) {
1216 /* Create default channel */
1217 attr = channel_new_default_attr(domain);
1218 if (attr == NULL) {
1219 ret = LTTNG_ERR_FATAL;
1220 goto error;
1221 }
1222 strncpy(attr->name, channel_name, sizeof(attr->name));
1223
1224 ret = cmd_enable_channel(session, domain, attr, wpipe);
1225 if (ret != LTTNG_OK) {
1226 free(attr);
1227 goto error;
1228 }
1229 free(attr);
1230
1231 /* Get the newly created channel reference back */
1232 uchan = trace_ust_find_channel_by_name(
1233 usess->domain_global.channels, channel_name);
1234 assert(uchan);
1235 }
1236
1237 /* At this point, the session and channel exist on the tracer */
1238 ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
1239 if (ret != LTTNG_OK) {
1240 goto error;
1241 }
1242 break;
1243 }
1244 #if 0
1245 case LTTNG_DOMAIN_UST_EXEC_NAME:
1246 case LTTNG_DOMAIN_UST_PID:
1247 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1248 #endif
1249 default:
1250 ret = LTTNG_ERR_UND;
1251 goto error;
1252 }
1253
1254 ret = LTTNG_OK;
1255
1256 error:
1257 rcu_read_unlock();
1258 return ret;
1259 }
1260
1261 /*
1262 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1263 */
1264 int cmd_enable_event_all(struct ltt_session *session, int domain,
1265 char *channel_name, int event_type,
1266 struct lttng_filter_bytecode *filter, int wpipe)
1267 {
1268 int ret;
1269 struct lttng_channel *attr;
1270
1271 assert(session);
1272 assert(channel_name);
1273
1274 rcu_read_lock();
1275
1276 switch (domain) {
1277 case LTTNG_DOMAIN_KERNEL:
1278 {
1279 struct ltt_kernel_channel *kchan;
1280
1281 assert(session->kernel_session);
1282
1283 kchan = trace_kernel_get_channel_by_name(channel_name,
1284 session->kernel_session);
1285 if (kchan == NULL) {
1286 /* Create default channel */
1287 attr = channel_new_default_attr(domain);
1288 if (attr == NULL) {
1289 ret = LTTNG_ERR_FATAL;
1290 goto error;
1291 }
1292 strncpy(attr->name, channel_name, sizeof(attr->name));
1293
1294 ret = cmd_enable_channel(session, domain, attr, wpipe);
1295 if (ret != LTTNG_OK) {
1296 free(attr);
1297 goto error;
1298 }
1299 free(attr);
1300
1301 /* Get the newly created kernel channel pointer */
1302 kchan = trace_kernel_get_channel_by_name(channel_name,
1303 session->kernel_session);
1304 assert(kchan);
1305 }
1306
1307 switch (event_type) {
1308 case LTTNG_EVENT_SYSCALL:
1309 ret = event_kernel_enable_all_syscalls(kchan, kernel_tracer_fd);
1310 break;
1311 case LTTNG_EVENT_TRACEPOINT:
1312 /*
1313 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1314 * events already registered to the channel.
1315 */
1316 ret = event_kernel_enable_all_tracepoints(kchan, kernel_tracer_fd);
1317 break;
1318 case LTTNG_EVENT_ALL:
1319 /* Enable syscalls and tracepoints */
1320 ret = event_kernel_enable_all(kchan, kernel_tracer_fd);
1321 break;
1322 default:
1323 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1324 goto error;
1325 }
1326
1327 /* Manage return value */
1328 if (ret != LTTNG_OK) {
1329 /*
1330 * On error, cmd_enable_channel call will take care of destroying
1331 * the created channel if it was needed.
1332 */
1333 goto error;
1334 }
1335
1336 kernel_wait_quiescent(kernel_tracer_fd);
1337 break;
1338 }
1339 case LTTNG_DOMAIN_UST:
1340 {
1341 struct ltt_ust_channel *uchan;
1342 struct ltt_ust_session *usess = session->ust_session;
1343
1344 assert(usess);
1345
1346 /* Get channel from global UST domain */
1347 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1348 channel_name);
1349 if (uchan == NULL) {
1350 /* Create default channel */
1351 attr = channel_new_default_attr(domain);
1352 if (attr == NULL) {
1353 ret = LTTNG_ERR_FATAL;
1354 goto error;
1355 }
1356 strncpy(attr->name, channel_name, sizeof(attr->name));
1357
1358 ret = cmd_enable_channel(session, domain, attr, wpipe);
1359 if (ret != LTTNG_OK) {
1360 free(attr);
1361 goto error;
1362 }
1363 free(attr);
1364
1365 /* Get the newly created channel reference back */
1366 uchan = trace_ust_find_channel_by_name(
1367 usess->domain_global.channels, channel_name);
1368 assert(uchan);
1369 }
1370
1371 /* At this point, the session and channel exist on the tracer */
1372
1373 switch (event_type) {
1374 case LTTNG_EVENT_ALL:
1375 case LTTNG_EVENT_TRACEPOINT:
1376 ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
1377 filter);
1378 if (ret != LTTNG_OK) {
1379 goto error;
1380 }
1381 break;
1382 default:
1383 ret = LTTNG_ERR_UST_ENABLE_FAIL;
1384 goto error;
1385 }
1386
1387 /* Manage return value */
1388 if (ret != LTTNG_OK) {
1389 goto error;
1390 }
1391
1392 break;
1393 }
1394 #if 0
1395 case LTTNG_DOMAIN_UST_EXEC_NAME:
1396 case LTTNG_DOMAIN_UST_PID:
1397 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1398 #endif
1399 default:
1400 ret = LTTNG_ERR_UND;
1401 goto error;
1402 }
1403
1404 ret = LTTNG_OK;
1405
1406 error:
1407 rcu_read_unlock();
1408 return ret;
1409 }
1410
1411
1412 /*
1413 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1414 */
1415 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1416 {
1417 int ret;
1418 ssize_t nb_events = 0;
1419
1420 switch (domain) {
1421 case LTTNG_DOMAIN_KERNEL:
1422 nb_events = kernel_list_events(kernel_tracer_fd, events);
1423 if (nb_events < 0) {
1424 ret = LTTNG_ERR_KERN_LIST_FAIL;
1425 goto error;
1426 }
1427 break;
1428 case LTTNG_DOMAIN_UST:
1429 nb_events = ust_app_list_events(events);
1430 if (nb_events < 0) {
1431 ret = LTTNG_ERR_UST_LIST_FAIL;
1432 goto error;
1433 }
1434 break;
1435 default:
1436 ret = LTTNG_ERR_UND;
1437 goto error;
1438 }
1439
1440 return nb_events;
1441
1442 error:
1443 /* Return negative value to differentiate return code */
1444 return -ret;
1445 }
1446
1447 /*
1448 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1449 */
1450 ssize_t cmd_list_tracepoint_fields(int domain,
1451 struct lttng_event_field **fields)
1452 {
1453 int ret;
1454 ssize_t nb_fields = 0;
1455
1456 switch (domain) {
1457 case LTTNG_DOMAIN_UST:
1458 nb_fields = ust_app_list_event_fields(fields);
1459 if (nb_fields < 0) {
1460 ret = LTTNG_ERR_UST_LIST_FAIL;
1461 goto error;
1462 }
1463 break;
1464 case LTTNG_DOMAIN_KERNEL:
1465 default: /* fall-through */
1466 ret = LTTNG_ERR_UND;
1467 goto error;
1468 }
1469
1470 return nb_fields;
1471
1472 error:
1473 /* Return negative value to differentiate return code */
1474 return -ret;
1475 }
1476
1477 /*
1478 * Command LTTNG_START_TRACE processed by the client thread.
1479 */
1480 int cmd_start_trace(struct ltt_session *session)
1481 {
1482 int ret;
1483 struct ltt_kernel_session *ksession;
1484 struct ltt_ust_session *usess;
1485
1486 assert(session);
1487
1488 /* Ease our life a bit ;) */
1489 ksession = session->kernel_session;
1490 usess = session->ust_session;
1491
1492 if (session->enabled) {
1493 /* Already started. */
1494 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1495 goto error;
1496 }
1497
1498 session->enabled = 1;
1499
1500 /* Kernel tracing */
1501 if (ksession != NULL) {
1502 ret = start_kernel_session(ksession, kernel_tracer_fd);
1503 if (ret != LTTNG_OK) {
1504 goto error;
1505 }
1506 }
1507
1508 /* Flag session that trace should start automatically */
1509 if (usess) {
1510 usess->start_trace = 1;
1511
1512 ret = ust_app_start_trace_all(usess);
1513 if (ret < 0) {
1514 ret = LTTNG_ERR_UST_START_FAIL;
1515 goto error;
1516 }
1517 }
1518
1519 session->started = 1;
1520
1521 ret = LTTNG_OK;
1522
1523 error:
1524 return ret;
1525 }
1526
1527 /*
1528 * Command LTTNG_STOP_TRACE processed by the client thread.
1529 */
1530 int cmd_stop_trace(struct ltt_session *session)
1531 {
1532 int ret;
1533 struct ltt_kernel_channel *kchan;
1534 struct ltt_kernel_session *ksession;
1535 struct ltt_ust_session *usess;
1536
1537 assert(session);
1538
1539 /* Short cut */
1540 ksession = session->kernel_session;
1541 usess = session->ust_session;
1542
1543 if (!session->enabled) {
1544 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1545 goto error;
1546 }
1547
1548 session->enabled = 0;
1549
1550 /* Kernel tracer */
1551 if (ksession) {
1552 DBG("Stop kernel tracing");
1553
1554 /* Flush metadata if exist */
1555 if (ksession->metadata_stream_fd >= 0) {
1556 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1557 if (ret < 0) {
1558 ERR("Kernel metadata flush failed");
1559 }
1560 }
1561
1562 /* Flush all buffers before stopping */
1563 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1564 ret = kernel_flush_buffer(kchan);
1565 if (ret < 0) {
1566 ERR("Kernel flush buffer error");
1567 }
1568 }
1569
1570 ret = kernel_stop_session(ksession);
1571 if (ret < 0) {
1572 ret = LTTNG_ERR_KERN_STOP_FAIL;
1573 goto error;
1574 }
1575
1576 kernel_wait_quiescent(kernel_tracer_fd);
1577
1578 ksession->started = 0;
1579 }
1580
1581 if (usess) {
1582 usess->start_trace = 0;
1583
1584 ret = ust_app_stop_trace_all(usess);
1585 if (ret < 0) {
1586 ret = LTTNG_ERR_UST_STOP_FAIL;
1587 goto error;
1588 }
1589 }
1590
1591 session->started = 0;
1592
1593 ret = LTTNG_OK;
1594
1595 error:
1596 return ret;
1597 }
1598
1599 /*
1600 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1601 */
1602 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1603 size_t nb_uri, struct lttng_uri *uris)
1604 {
1605 int ret, i;
1606 struct ltt_kernel_session *ksess = session->kernel_session;
1607 struct ltt_ust_session *usess = session->ust_session;
1608 struct consumer_output *consumer = NULL;
1609
1610 assert(session);
1611 assert(uris);
1612 assert(nb_uri > 0);
1613
1614 /* Can't enable consumer after session started. */
1615 if (session->enabled) {
1616 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1617 goto error;
1618 }
1619
1620 /*
1621 * This case switch makes sure the domain session has a temporary consumer
1622 * so the URL can be set.
1623 */
1624 switch (domain) {
1625 case 0:
1626 /* Code flow error. A session MUST always have a consumer object */
1627 assert(session->consumer);
1628 /*
1629 * The URL will be added to the tracing session consumer instead of a
1630 * specific domain consumer.
1631 */
1632 consumer = session->consumer;
1633 break;
1634 case LTTNG_DOMAIN_KERNEL:
1635 /* Code flow error if we don't have a kernel session here. */
1636 assert(ksess);
1637
1638 /* Create consumer output if none exists */
1639 consumer = ksess->tmp_consumer;
1640 if (consumer == NULL) {
1641 consumer = consumer_copy_output(ksess->consumer);
1642 if (consumer == NULL) {
1643 ret = LTTNG_ERR_FATAL;
1644 goto error;
1645 }
1646 /* Trash the consumer subdir, we are about to set a new one. */
1647 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1648 ksess->tmp_consumer = consumer;
1649 }
1650
1651 break;
1652 case LTTNG_DOMAIN_UST:
1653 /* Code flow error if we don't have a kernel session here. */
1654 assert(usess);
1655
1656 /* Create consumer output if none exists */
1657 consumer = usess->tmp_consumer;
1658 if (consumer == NULL) {
1659 consumer = consumer_copy_output(usess->consumer);
1660 if (consumer == NULL) {
1661 ret = LTTNG_ERR_FATAL;
1662 goto error;
1663 }
1664 /* Trash the consumer subdir, we are about to set a new one. */
1665 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1666 usess->tmp_consumer = consumer;
1667 }
1668
1669 break;
1670 }
1671
1672 for (i = 0; i < nb_uri; i++) {
1673 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1674 if (ret < 0) {
1675 goto error;
1676 }
1677 }
1678
1679 /* All good! */
1680 ret = LTTNG_OK;
1681
1682 error:
1683 return ret;
1684 }
1685
1686 /*
1687 * Command LTTNG_CREATE_SESSION processed by the client thread.
1688 */
1689 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1690 size_t nb_uri, lttng_sock_cred *creds)
1691 {
1692 int ret;
1693 char *path = NULL;
1694 struct ltt_session *session;
1695
1696 assert(name);
1697
1698 /*
1699 * Verify if the session already exist
1700 *
1701 * XXX: There is no need for the session lock list here since the caller
1702 * (process_client_msg) is holding it. We might want to change that so a
1703 * single command does not lock the entire session list.
1704 */
1705 session = session_find_by_name(name);
1706 if (session != NULL) {
1707 ret = LTTNG_ERR_EXIST_SESS;
1708 goto find_error;
1709 }
1710
1711 /* Create tracing session in the registry */
1712 ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1713 LTTNG_SOCK_GET_GID_CRED(creds));
1714 if (ret != LTTNG_OK) {
1715 goto session_error;
1716 }
1717
1718 /*
1719 * Get the newly created session pointer back
1720 *
1721 * XXX: There is no need for the session lock list here since the caller
1722 * (process_client_msg) is holding it. We might want to change that so a
1723 * single command does not lock the entire session list.
1724 */
1725 session = session_find_by_name(name);
1726 assert(session);
1727
1728 /* Create default consumer output for the session not yet created. */
1729 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1730 if (session->consumer == NULL) {
1731 ret = LTTNG_ERR_FATAL;
1732 goto consumer_error;
1733 }
1734
1735 /*
1736 * This means that the lttng_create_session call was called with the _path_
1737 * argument set to NULL.
1738 */
1739 if (uris == NULL) {
1740 /*
1741 * At this point, we'll skip the consumer URI setup and create a
1742 * session with a NULL path which will flag the session to NOT spawn a
1743 * consumer.
1744 */
1745 DBG("Create session %s with NO uri, skipping consumer setup", name);
1746 goto end;
1747 }
1748
1749 session->start_consumer = 1;
1750
1751 ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1752 if (ret != LTTNG_OK) {
1753 goto consumer_error;
1754 }
1755
1756 session->consumer->enabled = 1;
1757
1758 end:
1759 return LTTNG_OK;
1760
1761 consumer_error:
1762 session_destroy(session);
1763 session_error:
1764 find_error:
1765 return ret;
1766 }
1767
1768 /*
1769 * Command LTTNG_DESTROY_SESSION processed by the client thread.
1770 */
1771 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1772 {
1773 int ret;
1774 struct ltt_ust_session *usess;
1775 struct ltt_kernel_session *ksess;
1776
1777 /* Safety net */
1778 assert(session);
1779
1780 usess = session->ust_session;
1781 ksess = session->kernel_session;
1782
1783 /* Clean kernel session teardown */
1784 kernel_destroy_session(ksess);
1785
1786 /* UST session teardown */
1787 if (usess) {
1788 /* Close any relayd session */
1789 consumer_output_send_destroy_relayd(usess->consumer);
1790
1791 /* Destroy every UST application related to this session. */
1792 ret = ust_app_destroy_trace_all(usess);
1793 if (ret) {
1794 ERR("Error in ust_app_destroy_trace_all");
1795 }
1796
1797 /* Clean up the rest. */
1798 trace_ust_destroy_session(usess);
1799 }
1800
1801 /*
1802 * Must notify the kernel thread here to update it's poll set in order to
1803 * remove the channel(s)' fd just destroyed.
1804 */
1805 ret = notify_thread_pipe(wpipe);
1806 if (ret < 0) {
1807 PERROR("write kernel poll pipe");
1808 }
1809
1810 ret = session_destroy(session);
1811
1812 return ret;
1813 }
1814
1815 /*
1816 * Command LTTNG_CALIBRATE processed by the client thread.
1817 */
1818 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1819 {
1820 int ret;
1821
1822 switch (domain) {
1823 case LTTNG_DOMAIN_KERNEL:
1824 {
1825 struct lttng_kernel_calibrate kcalibrate;
1826
1827 kcalibrate.type = calibrate->type;
1828 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1829 if (ret < 0) {
1830 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1831 goto error;
1832 }
1833 break;
1834 }
1835 case LTTNG_DOMAIN_UST:
1836 {
1837 struct lttng_ust_calibrate ucalibrate;
1838
1839 ucalibrate.type = calibrate->type;
1840 ret = ust_app_calibrate_glb(&ucalibrate);
1841 if (ret < 0) {
1842 ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1843 goto error;
1844 }
1845 break;
1846 }
1847 default:
1848 ret = LTTNG_ERR_UND;
1849 goto error;
1850 }
1851
1852 ret = LTTNG_OK;
1853
1854 error:
1855 return ret;
1856 }
1857
1858 /*
1859 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1860 */
1861 int cmd_register_consumer(struct ltt_session *session, int domain,
1862 const char *sock_path, struct consumer_data *cdata)
1863 {
1864 int ret, sock;
1865 struct consumer_socket *socket;
1866
1867 assert(session);
1868 assert(cdata);
1869 assert(sock_path);
1870
1871 switch (domain) {
1872 case LTTNG_DOMAIN_KERNEL:
1873 {
1874 struct ltt_kernel_session *ksess = session->kernel_session;
1875
1876 assert(ksess);
1877
1878 /* Can't register a consumer if there is already one */
1879 if (ksess->consumer_fds_sent != 0) {
1880 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1881 goto error;
1882 }
1883
1884 sock = lttcomm_connect_unix_sock(sock_path);
1885 if (sock < 0) {
1886 ret = LTTNG_ERR_CONNECT_FAIL;
1887 goto error;
1888 }
1889
1890 socket = consumer_allocate_socket(sock);
1891 if (socket == NULL) {
1892 ret = close(sock);
1893 if (ret < 0) {
1894 PERROR("close register consumer");
1895 }
1896 ret = LTTNG_ERR_FATAL;
1897 goto error;
1898 }
1899
1900 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1901 if (socket->lock == NULL) {
1902 PERROR("zmalloc pthread mutex");
1903 ret = LTTNG_ERR_FATAL;
1904 goto error;
1905 }
1906 pthread_mutex_init(socket->lock, NULL);
1907 socket->registered = 1;
1908
1909 rcu_read_lock();
1910 consumer_add_socket(socket, ksess->consumer);
1911 rcu_read_unlock();
1912
1913 pthread_mutex_lock(&cdata->pid_mutex);
1914 cdata->pid = -1;
1915 pthread_mutex_unlock(&cdata->pid_mutex);
1916
1917 break;
1918 }
1919 default:
1920 /* TODO: Userspace tracing */
1921 ret = LTTNG_ERR_UND;
1922 goto error;
1923 }
1924
1925 ret = LTTNG_OK;
1926
1927 error:
1928 return ret;
1929 }
1930
1931 /*
1932 * Command LTTNG_LIST_DOMAINS processed by the client thread.
1933 */
1934 ssize_t cmd_list_domains(struct ltt_session *session,
1935 struct lttng_domain **domains)
1936 {
1937 int ret, index = 0;
1938 ssize_t nb_dom = 0;
1939
1940 if (session->kernel_session != NULL) {
1941 DBG3("Listing domains found kernel domain");
1942 nb_dom++;
1943 }
1944
1945 if (session->ust_session != NULL) {
1946 DBG3("Listing domains found UST global domain");
1947 nb_dom++;
1948 }
1949
1950 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1951 if (*domains == NULL) {
1952 ret = LTTNG_ERR_FATAL;
1953 goto error;
1954 }
1955
1956 if (session->kernel_session != NULL) {
1957 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1958 index++;
1959 }
1960
1961 if (session->ust_session != NULL) {
1962 (*domains)[index].type = LTTNG_DOMAIN_UST;
1963 index++;
1964 }
1965
1966 return nb_dom;
1967
1968 error:
1969 /* Return negative value to differentiate return code */
1970 return -ret;
1971 }
1972
1973
1974 /*
1975 * Command LTTNG_LIST_CHANNELS processed by the client thread.
1976 */
1977 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1978 struct lttng_channel **channels)
1979 {
1980 int ret;
1981 ssize_t nb_chan = 0;
1982
1983 switch (domain) {
1984 case LTTNG_DOMAIN_KERNEL:
1985 if (session->kernel_session != NULL) {
1986 nb_chan = session->kernel_session->channel_count;
1987 }
1988 DBG3("Number of kernel channels %zd", nb_chan);
1989 if (nb_chan <= 0) {
1990 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1991 }
1992 break;
1993 case LTTNG_DOMAIN_UST:
1994 if (session->ust_session != NULL) {
1995 nb_chan = lttng_ht_get_count(
1996 session->ust_session->domain_global.channels);
1997 }
1998 DBG3("Number of UST global channels %zd", nb_chan);
1999 if (nb_chan <= 0) {
2000 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2001 }
2002 break;
2003 default:
2004 *channels = NULL;
2005 ret = LTTNG_ERR_UND;
2006 goto error;
2007 }
2008
2009 if (nb_chan > 0) {
2010 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2011 if (*channels == NULL) {
2012 ret = LTTNG_ERR_FATAL;
2013 goto error;
2014 }
2015
2016 list_lttng_channels(domain, session, *channels);
2017 } else {
2018 *channels = NULL;
2019 /* Ret value was set in the domain switch case */
2020 goto error;
2021 }
2022
2023 return nb_chan;
2024
2025 error:
2026 /* Return negative value to differentiate return code */
2027 return -ret;
2028 }
2029
2030 /*
2031 * Command LTTNG_LIST_EVENTS processed by the client thread.
2032 */
2033 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2034 char *channel_name, struct lttng_event **events)
2035 {
2036 int ret = 0;
2037 ssize_t nb_event = 0;
2038
2039 switch (domain) {
2040 case LTTNG_DOMAIN_KERNEL:
2041 if (session->kernel_session != NULL) {
2042 nb_event = list_lttng_kernel_events(channel_name,
2043 session->kernel_session, events);
2044 }
2045 break;
2046 case LTTNG_DOMAIN_UST:
2047 {
2048 if (session->ust_session != NULL) {
2049 nb_event = list_lttng_ust_global_events(channel_name,
2050 &session->ust_session->domain_global, events);
2051 }
2052 break;
2053 }
2054 default:
2055 ret = LTTNG_ERR_UND;
2056 goto error;
2057 }
2058
2059 return nb_event;
2060
2061 error:
2062 /* Return negative value to differentiate return code */
2063 return -ret;
2064 }
2065
2066 /*
2067 * Using the session list, filled a lttng_session array to send back to the
2068 * client for session listing.
2069 *
2070 * The session list lock MUST be acquired before calling this function. Use
2071 * session_lock_list() and session_unlock_list().
2072 */
2073 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2074 gid_t gid)
2075 {
2076 int ret;
2077 unsigned int i = 0;
2078 struct ltt_session *session;
2079 struct ltt_session_list *list = session_get_list();
2080
2081 DBG("Getting all available session for UID %d GID %d",
2082 uid, gid);
2083 /*
2084 * Iterate over session list and append data after the control struct in
2085 * the buffer.
2086 */
2087 cds_list_for_each_entry(session, &list->head, list) {
2088 /*
2089 * Only list the sessions the user can control.
2090 */
2091 if (!session_access_ok(session, uid, gid)) {
2092 continue;
2093 }
2094
2095 struct ltt_kernel_session *ksess = session->kernel_session;
2096 struct ltt_ust_session *usess = session->ust_session;
2097
2098 if (session->consumer->type == CONSUMER_DST_NET ||
2099 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2100 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2101 ret = build_network_session_path(sessions[i].path,
2102 sizeof(session[i].path), session);
2103 } else {
2104 ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2105 session->consumer->dst.trace_path);
2106 }
2107 if (ret < 0) {
2108 PERROR("snprintf session path");
2109 continue;
2110 }
2111
2112 strncpy(sessions[i].name, session->name, NAME_MAX);
2113 sessions[i].name[NAME_MAX - 1] = '\0';
2114 sessions[i].enabled = session->enabled;
2115 i++;
2116 }
2117 }
2118
2119 /*
2120 * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2121 */
2122 int cmd_disable_consumer(int domain, struct ltt_session *session)
2123 {
2124 int ret;
2125 struct ltt_kernel_session *ksess = session->kernel_session;
2126 struct ltt_ust_session *usess = session->ust_session;
2127 struct consumer_output *consumer;
2128
2129 assert(session);
2130
2131 if (session->enabled) {
2132 /* Can't disable consumer on an already started session */
2133 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2134 goto error;
2135 }
2136
2137 if (!session->start_consumer) {
2138 ret = LTTNG_ERR_NO_CONSUMER;
2139 goto error;
2140 }
2141
2142 switch (domain) {
2143 case 0:
2144 DBG("Disable tracing session %s consumer", session->name);
2145 consumer = session->consumer;
2146 break;
2147 case LTTNG_DOMAIN_KERNEL:
2148 /* Code flow error if we don't have a kernel session here. */
2149 assert(ksess);
2150
2151 DBG("Disabling kernel consumer");
2152 consumer = ksess->consumer;
2153
2154 break;
2155 case LTTNG_DOMAIN_UST:
2156 /* Code flow error if we don't have a UST session here. */
2157 assert(usess);
2158
2159 DBG("Disabling UST consumer");
2160 consumer = usess->consumer;
2161
2162 break;
2163 default:
2164 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2165 goto error;
2166 }
2167
2168 if (consumer) {
2169 consumer->enabled = 0;
2170 /* Success at this point */
2171 ret = LTTNG_OK;
2172 } else {
2173 ret = LTTNG_ERR_NO_CONSUMER;
2174 }
2175
2176 error:
2177 return ret;
2178 }
2179
2180 /*
2181 * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2182 */
2183 int cmd_enable_consumer(int domain, struct ltt_session *session)
2184 {
2185 int ret;
2186 struct ltt_kernel_session *ksess = session->kernel_session;
2187 struct ltt_ust_session *usess = session->ust_session;
2188 struct consumer_output *consumer = NULL;
2189
2190 assert(session);
2191
2192 /* Can't enable consumer after session started. */
2193 if (session->enabled) {
2194 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2195 goto error;
2196 }
2197
2198 switch (domain) {
2199 case 0:
2200 assert(session->consumer);
2201 consumer = session->consumer;
2202 break;
2203 case LTTNG_DOMAIN_KERNEL:
2204 /* Code flow error if we don't have a kernel session here. */
2205 assert(ksess);
2206
2207 /*
2208 * Check if we have already sent fds to the consumer. In that case,
2209 * the enable-consumer command can't be used because a start trace
2210 * had previously occured.
2211 */
2212 if (ksess->consumer_fds_sent) {
2213 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2214 goto error;
2215 }
2216
2217 consumer = ksess->tmp_consumer;
2218 if (consumer == NULL) {
2219 ret = LTTNG_OK;
2220 /* No temp. consumer output exists. Using the current one. */
2221 DBG3("No temporary consumer. Using default");
2222 consumer = ksess->consumer;
2223 goto error;
2224 }
2225
2226 switch (consumer->type) {
2227 case CONSUMER_DST_LOCAL:
2228 DBG2("Consumer output is local. Creating directory(ies)");
2229
2230 /* Create directory(ies) */
2231 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2232 S_IRWXU | S_IRWXG, session->uid, session->gid);
2233 if (ret < 0) {
2234 if (ret != -EEXIST) {
2235 ERR("Trace directory creation error");
2236 ret = LTTNG_ERR_FATAL;
2237 goto error;
2238 }
2239 }
2240 break;
2241 case CONSUMER_DST_NET:
2242 DBG2("Consumer output is network. Validating URIs");
2243 /* Validate if we have both control and data path set. */
2244 if (!consumer->dst.net.control_isset) {
2245 ret = LTTNG_ERR_URL_CTRL_MISS;
2246 goto error;
2247 }
2248
2249 if (!consumer->dst.net.data_isset) {
2250 ret = LTTNG_ERR_URL_DATA_MISS;
2251 goto error;
2252 }
2253
2254 /* Check established network session state */
2255 if (session->net_handle == 0) {
2256 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2257 ERR("Session network handle is not set on enable-consumer");
2258 goto error;
2259 }
2260
2261 break;
2262 }
2263
2264 /*
2265 * @session-lock
2266 * This is race free for now since the session lock is acquired before
2267 * ending up in this function. No other threads can access this kernel
2268 * session without this lock hence freeing the consumer output object
2269 * is valid.
2270 */
2271 rcu_read_lock();
2272 /* Destroy current consumer. We are about to replace it */
2273 consumer_destroy_output(ksess->consumer);
2274 rcu_read_unlock();
2275 ksess->consumer = consumer;
2276 ksess->tmp_consumer = NULL;
2277
2278 break;
2279 case LTTNG_DOMAIN_UST:
2280 /* Code flow error if we don't have a UST session here. */
2281 assert(usess);
2282
2283 /*
2284 * Check if we have already sent fds to the consumer. In that case,
2285 * the enable-consumer command can't be used because a start trace
2286 * had previously occured.
2287 */
2288 if (usess->start_trace) {
2289 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2290 goto error;
2291 }
2292
2293 consumer = usess->tmp_consumer;
2294 if (consumer == NULL) {
2295 ret = LTTNG_OK;
2296 /* No temp. consumer output exists. Using the current one. */
2297 DBG3("No temporary consumer. Using default");
2298 consumer = usess->consumer;
2299 goto error;
2300 }
2301
2302 switch (consumer->type) {
2303 case CONSUMER_DST_LOCAL:
2304 DBG2("Consumer output is local. Creating directory(ies)");
2305
2306 /* Create directory(ies) */
2307 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2308 S_IRWXU | S_IRWXG, session->uid, session->gid);
2309 if (ret < 0) {
2310 if (ret != -EEXIST) {
2311 ERR("Trace directory creation error");
2312 ret = LTTNG_ERR_FATAL;
2313 goto error;
2314 }
2315 }
2316 break;
2317 case CONSUMER_DST_NET:
2318 DBG2("Consumer output is network. Validating URIs");
2319 /* Validate if we have both control and data path set. */
2320 if (!consumer->dst.net.control_isset) {
2321 ret = LTTNG_ERR_URL_CTRL_MISS;
2322 goto error;
2323 }
2324
2325 if (!consumer->dst.net.data_isset) {
2326 ret = LTTNG_ERR_URL_DATA_MISS;
2327 goto error;
2328 }
2329
2330 /* Check established network session state */
2331 if (session->net_handle == 0) {
2332 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2333 DBG2("Session network handle is not set on enable-consumer");
2334 goto error;
2335 }
2336
2337 if (consumer->net_seq_index == -1) {
2338 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2339 DBG2("Network index is not set on the consumer");
2340 goto error;
2341 }
2342
2343 break;
2344 }
2345
2346 /*
2347 * @session-lock
2348 * This is race free for now since the session lock is acquired before
2349 * ending up in this function. No other threads can access this kernel
2350 * session without this lock hence freeing the consumer output object
2351 * is valid.
2352 */
2353 rcu_read_lock();
2354 /* Destroy current consumer. We are about to replace it */
2355 consumer_destroy_output(usess->consumer);
2356 rcu_read_unlock();
2357 usess->consumer = consumer;
2358 usess->tmp_consumer = NULL;
2359
2360 break;
2361 }
2362
2363 session->start_consumer = 1;
2364
2365 /* Enable it */
2366 if (consumer) {
2367 consumer->enabled = 1;
2368 /* Success at this point */
2369 ret = LTTNG_OK;
2370 } else {
2371 /* Should not really happend... */
2372 ret = LTTNG_ERR_NO_CONSUMER;
2373 }
2374
2375 error:
2376 return ret;
2377 }
2378
2379 /*
2380 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2381 * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2382 */
2383 int cmd_data_pending(struct ltt_session *session)
2384 {
2385 int ret;
2386 struct ltt_kernel_session *ksess = session->kernel_session;
2387 struct ltt_ust_session *usess = session->ust_session;
2388
2389 assert(session);
2390
2391 /* Session MUST be stopped to ask for data availability. */
2392 if (session->enabled) {
2393 ret = LTTNG_ERR_SESSION_STARTED;
2394 goto error;
2395 }
2396
2397 if (ksess && ksess->consumer) {
2398 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2399 if (ret == 1) {
2400 /* Data is still being extracted for the kernel. */
2401 goto error;
2402 }
2403 }
2404
2405 if (usess && usess->consumer) {
2406 ret = consumer_is_data_pending(usess->id, usess->consumer);
2407 if (ret == 1) {
2408 /* Data is still being extracted for the kernel. */
2409 goto error;
2410 }
2411 }
2412
2413 /* Data is ready to be read by a viewer */
2414 ret = 0;
2415
2416 error:
2417 return ret;
2418 }
2419
2420 /*
2421 * Init command subsystem.
2422 */
2423 void cmd_init(void)
2424 {
2425 /*
2426 * Set network sequence index to 1 for streams to match a relayd socket on
2427 * the consumer side.
2428 */
2429 uatomic_set(&relayd_net_seq_idx, 1);
2430
2431 DBG("Command subsystem initialized");
2432 }
LTTng 2.0 tools and control repository
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