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