Fix: add missing rcu lock for UST lookup
[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 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 /* Set URI into consumer output object */
380 ret = consumer_set_network_uri(consumer, uri);
381 if (ret < 0) {
382 ret = LTTNG_ERR_FATAL;
383 goto error;
384 } else if (ret == 1) {
385 /*
386 * URI was the same in the consumer so we do not append the subdir
387 * again so to not duplicate output dir.
388 */
389 goto error;
390 }
391
392 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
393 ret = consumer_set_subdir(consumer, session_name);
394 if (ret < 0) {
395 ret = LTTNG_ERR_FATAL;
396 goto error;
397 }
398 }
399
400 if (uri->stype == LTTNG_STREAM_CONTROL) {
401 /* On a new subdir, reappend the default trace dir. */
402 strncat(consumer->subdir, default_trace_dir,
403 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
404 DBG3("Append domain trace name to subdir %s", consumer->subdir);
405 }
406
407 break;
408 case LTTNG_DST_PATH:
409 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
410 memset(consumer->dst.trace_path, 0,
411 sizeof(consumer->dst.trace_path));
412 strncpy(consumer->dst.trace_path, uri->dst.path,
413 sizeof(consumer->dst.trace_path));
414 /* Append default trace dir */
415 strncat(consumer->dst.trace_path, default_trace_dir,
416 sizeof(consumer->dst.trace_path) -
417 strlen(consumer->dst.trace_path) - 1);
418 /* Flag consumer as local. */
419 consumer->type = CONSUMER_DST_LOCAL;
420 break;
421 }
422
423 error:
424 return ret;
425 }
426
427 /*
428 * Init tracing by creating trace directory and sending fds kernel consumer.
429 */
430 static int init_kernel_tracing(struct ltt_kernel_session *session)
431 {
432 int ret = 0;
433 struct lttng_ht_iter iter;
434 struct consumer_socket *socket;
435
436 assert(session);
437
438 rcu_read_lock();
439
440 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
441 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
442 socket, node.node) {
443 /* Code flow error */
444 assert(socket->fd >= 0);
445
446 pthread_mutex_lock(socket->lock);
447 ret = kernel_consumer_send_session(socket, session);
448 pthread_mutex_unlock(socket->lock);
449 if (ret < 0) {
450 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
451 goto error;
452 }
453 }
454 }
455
456 error:
457 rcu_read_unlock();
458 return ret;
459 }
460
461 /*
462 * Create a socket to the relayd using the URI.
463 *
464 * On success, the relayd_sock pointer is set to the created socket.
465 * Else, it's stays untouched and a lttcomm error code is returned.
466 */
467 static int create_connect_relayd(struct consumer_output *output,
468 const char *session_name, struct lttng_uri *uri,
469 struct lttcomm_sock **relayd_sock)
470 {
471 int ret;
472 struct lttcomm_sock *sock;
473
474 /* Create socket object from URI */
475 sock = lttcomm_alloc_sock_from_uri(uri);
476 if (sock == NULL) {
477 ret = LTTNG_ERR_FATAL;
478 goto error;
479 }
480
481 ret = lttcomm_create_sock(sock);
482 if (ret < 0) {
483 ret = LTTNG_ERR_FATAL;
484 goto error;
485 }
486
487 /* Connect to relayd so we can proceed with a session creation. */
488 ret = relayd_connect(sock);
489 if (ret < 0) {
490 ERR("Unable to reach lttng-relayd");
491 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
492 goto free_sock;
493 }
494
495 /* Create socket for control stream. */
496 if (uri->stype == LTTNG_STREAM_CONTROL) {
497 DBG3("Creating relayd stream socket from URI");
498
499 /* Check relayd version */
500 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
501 RELAYD_VERSION_COMM_MINOR);
502 if (ret < 0) {
503 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
504 goto close_sock;
505 }
506 } else if (uri->stype == LTTNG_STREAM_DATA) {
507 DBG3("Creating relayd data socket from URI");
508 } else {
509 /* Command is not valid */
510 ERR("Relayd invalid stream type: %d", uri->stype);
511 ret = LTTNG_ERR_INVALID;
512 goto close_sock;
513 }
514
515 *relayd_sock = sock;
516
517 return LTTNG_OK;
518
519 close_sock:
520 if (sock) {
521 (void) relayd_close(sock);
522 }
523 free_sock:
524 if (sock) {
525 lttcomm_destroy_sock(sock);
526 }
527 error:
528 return ret;
529 }
530
531 /*
532 * Connect to the relayd using URI and send the socket to the right consumer.
533 */
534 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
535 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
536 struct consumer_socket *consumer_sock)
537 {
538 int ret;
539 struct lttcomm_sock *sock = NULL;
540
541 /* Set the network sequence index if not set. */
542 if (consumer->net_seq_index == -1) {
543 /*
544 * Increment net_seq_idx because we are about to transfer the
545 * new relayd socket to the consumer.
546 */
547 uatomic_inc(&relayd_net_seq_idx);
548 /* Assign unique key so the consumer can match streams */
549 uatomic_set(&consumer->net_seq_index,
550 uatomic_read(&relayd_net_seq_idx));
551 }
552
553 /* Connect to relayd and make version check if uri is the control. */
554 ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
555 if (ret != LTTNG_OK) {
556 goto close_sock;
557 }
558
559 /* If the control socket is connected, network session is ready */
560 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
561 session->net_handle = 1;
562 }
563
564 /* Send relayd socket to consumer. */
565 ret = consumer_send_relayd_socket(consumer_sock, sock,
566 consumer, relayd_uri->stype, session->id);
567 if (ret < 0) {
568 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
569 goto close_sock;
570 }
571
572 /* Flag that the corresponding socket was sent. */
573 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
574 consumer->dst.net.control_sock_sent = 1;
575 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
576 consumer->dst.net.data_sock_sent = 1;
577 }
578
579 ret = LTTNG_OK;
580
581 /*
582 * Close socket which was dup on the consumer side. The session daemon does
583 * NOT keep track of the relayd socket(s) once transfer to the consumer.
584 */
585
586 close_sock:
587 if (sock) {
588 (void) relayd_close(sock);
589 lttcomm_destroy_sock(sock);
590 }
591
592 return ret;
593 }
594
595 /*
596 * Send both relayd sockets to a specific consumer and domain. This is a
597 * helper function to facilitate sending the information to the consumer for a
598 * session.
599 */
600 static int send_consumer_relayd_sockets(int domain,
601 struct ltt_session *session, struct consumer_output *consumer,
602 struct consumer_socket *sock)
603 {
604 int ret = LTTNG_OK;
605
606 assert(session);
607 assert(consumer);
608
609 /* Sending control relayd socket. */
610 if (!consumer->dst.net.control_sock_sent) {
611 ret = send_consumer_relayd_socket(domain, session,
612 &consumer->dst.net.control, consumer, sock);
613 if (ret != LTTNG_OK) {
614 goto error;
615 }
616 }
617
618 /* Sending data relayd socket. */
619 if (!consumer->dst.net.data_sock_sent) {
620 ret = send_consumer_relayd_socket(domain, session,
621 &consumer->dst.net.data, consumer, sock);
622 if (ret != LTTNG_OK) {
623 goto error;
624 }
625 }
626
627 error:
628 return ret;
629 }
630
631 /*
632 * Setup relayd connections for a tracing session. First creates the socket to
633 * the relayd and send them to the right domain consumer. Consumer type MUST be
634 * network.
635 */
636 static int setup_relayd(struct ltt_session *session)
637 {
638 int ret = LTTNG_OK;
639 struct ltt_ust_session *usess;
640 struct ltt_kernel_session *ksess;
641 struct consumer_socket *socket;
642 struct lttng_ht_iter iter;
643
644 assert(session);
645
646 usess = session->ust_session;
647 ksess = session->kernel_session;
648
649 DBG2("Setting relayd for session %s", session->name);
650
651 rcu_read_lock();
652
653 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
654 && usess->consumer->enabled) {
655 /* For each consumer socket, send relayd sockets */
656 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
657 socket, node.node) {
658 /* Code flow error */
659 assert(socket->fd >= 0);
660
661 pthread_mutex_lock(socket->lock);
662 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
663 usess->consumer, socket);
664 pthread_mutex_unlock(socket->lock);
665 if (ret != LTTNG_OK) {
666 goto error;
667 }
668 }
669 }
670
671 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
672 && ksess->consumer->enabled) {
673 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
674 socket, node.node) {
675 /* Code flow error */
676 assert(socket->fd >= 0);
677
678 pthread_mutex_lock(socket->lock);
679 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
680 ksess->consumer, socket);
681 pthread_mutex_unlock(socket->lock);
682 if (ret != LTTNG_OK) {
683 goto error;
684 }
685 }
686 }
687
688 error:
689 rcu_read_unlock();
690 return ret;
691 }
692
693 /*
694 * Start a kernel session by opening all necessary streams.
695 */
696 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
697 {
698 int ret;
699 struct ltt_kernel_channel *kchan;
700
701 /* Open kernel metadata */
702 if (ksess->metadata == NULL) {
703 ret = kernel_open_metadata(ksess);
704 if (ret < 0) {
705 ret = LTTNG_ERR_KERN_META_FAIL;
706 goto error;
707 }
708 }
709
710 /* Open kernel metadata stream */
711 if (ksess->metadata_stream_fd < 0) {
712 ret = kernel_open_metadata_stream(ksess);
713 if (ret < 0) {
714 ERR("Kernel create metadata stream failed");
715 ret = LTTNG_ERR_KERN_STREAM_FAIL;
716 goto error;
717 }
718 }
719
720 /* For each channel */
721 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
722 if (kchan->stream_count == 0) {
723 ret = kernel_open_channel_stream(kchan);
724 if (ret < 0) {
725 ret = LTTNG_ERR_KERN_STREAM_FAIL;
726 goto error;
727 }
728 /* Update the stream global counter */
729 ksess->stream_count_global += ret;
730 }
731 }
732
733 /* Setup kernel consumer socket and send fds to it */
734 ret = init_kernel_tracing(ksess);
735 if (ret < 0) {
736 ret = LTTNG_ERR_KERN_START_FAIL;
737 goto error;
738 }
739
740 /* This start the kernel tracing */
741 ret = kernel_start_session(ksess);
742 if (ret < 0) {
743 ret = LTTNG_ERR_KERN_START_FAIL;
744 goto error;
745 }
746
747 /* Quiescent wait after starting trace */
748 kernel_wait_quiescent(kernel_tracer_fd);
749
750 ksess->started = 1;
751
752 ret = LTTNG_OK;
753
754 error:
755 return ret;
756 }
757
758 /*
759 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
760 */
761 int cmd_disable_channel(struct ltt_session *session, int domain,
762 char *channel_name)
763 {
764 int ret;
765 struct ltt_ust_session *usess;
766
767 usess = session->ust_session;
768
769 rcu_read_lock();
770
771 switch (domain) {
772 case LTTNG_DOMAIN_KERNEL:
773 {
774 ret = channel_kernel_disable(session->kernel_session,
775 channel_name);
776 if (ret != LTTNG_OK) {
777 goto error;
778 }
779
780 kernel_wait_quiescent(kernel_tracer_fd);
781 break;
782 }
783 case LTTNG_DOMAIN_UST:
784 {
785 struct ltt_ust_channel *uchan;
786 struct lttng_ht *chan_ht;
787
788 chan_ht = usess->domain_global.channels;
789
790 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
791 if (uchan == NULL) {
792 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
793 goto error;
794 }
795
796 ret = channel_ust_disable(usess, domain, uchan);
797 if (ret != LTTNG_OK) {
798 goto error;
799 }
800 break;
801 }
802 #if 0
803 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
804 case LTTNG_DOMAIN_UST_EXEC_NAME:
805 case LTTNG_DOMAIN_UST_PID:
806 #endif
807 default:
808 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
809 goto error;
810 }
811
812 ret = LTTNG_OK;
813
814 error:
815 rcu_read_unlock();
816 return ret;
817 }
818
819 /*
820 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
821 *
822 * The wpipe arguments is used as a notifier for the kernel thread.
823 */
824 int cmd_enable_channel(struct ltt_session *session,
825 int domain, struct lttng_channel *attr, int wpipe)
826 {
827 int ret;
828 struct ltt_ust_session *usess = session->ust_session;
829 struct lttng_ht *chan_ht;
830
831 assert(session);
832 assert(attr);
833
834 DBG("Enabling channel %s for session %s", attr->name, session->name);
835
836 rcu_read_lock();
837
838 switch (domain) {
839 case LTTNG_DOMAIN_KERNEL:
840 {
841 struct ltt_kernel_channel *kchan;
842
843 kchan = trace_kernel_get_channel_by_name(attr->name,
844 session->kernel_session);
845 if (kchan == NULL) {
846 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
847 } else {
848 ret = channel_kernel_enable(session->kernel_session, kchan);
849 }
850
851 if (ret != LTTNG_OK) {
852 goto error;
853 }
854
855 kernel_wait_quiescent(kernel_tracer_fd);
856
857 /*
858 * If the session was previously started, start as well this newly
859 * created kernel session so the events/channels enabled *after* the
860 * start actually work.
861 */
862 if (session->started && !session->kernel_session->started) {
863 ret = start_kernel_session(session->kernel_session, wpipe);
864 if (ret != LTTNG_OK) {
865 goto error;
866 }
867 }
868 break;
869 }
870 case LTTNG_DOMAIN_UST:
871 {
872 struct ltt_ust_channel *uchan;
873
874 chan_ht = usess->domain_global.channels;
875
876 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
877 if (uchan == NULL) {
878 ret = channel_ust_create(usess, domain, attr);
879 } else {
880 ret = channel_ust_enable(usess, domain, uchan);
881 }
882
883 /* Start the UST session if the session was already started. */
884 if (session->started && !usess->start_trace) {
885 ret = ust_app_start_trace_all(usess);
886 if (ret < 0) {
887 ret = LTTNG_ERR_UST_START_FAIL;
888 goto error;
889 }
890 ret = LTTNG_OK;
891 usess->start_trace = 1;
892 }
893 break;
894 }
895 #if 0
896 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
897 case LTTNG_DOMAIN_UST_EXEC_NAME:
898 case LTTNG_DOMAIN_UST_PID:
899 #endif
900 default:
901 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
902 goto error;
903 }
904
905 error:
906 rcu_read_unlock();
907 return ret;
908 }
909
910
911 /*
912 * Command LTTNG_DISABLE_EVENT processed by the client thread.
913 */
914 int cmd_disable_event(struct ltt_session *session, int domain,
915 char *channel_name, char *event_name)
916 {
917 int ret;
918
919 rcu_read_lock();
920
921 switch (domain) {
922 case LTTNG_DOMAIN_KERNEL:
923 {
924 struct ltt_kernel_channel *kchan;
925 struct ltt_kernel_session *ksess;
926
927 ksess = session->kernel_session;
928
929 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
930 if (kchan == NULL) {
931 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
932 goto error;
933 }
934
935 ret = event_kernel_disable_tracepoint(kchan, event_name);
936 if (ret != LTTNG_OK) {
937 goto error;
938 }
939
940 kernel_wait_quiescent(kernel_tracer_fd);
941 break;
942 }
943 case LTTNG_DOMAIN_UST:
944 {
945 struct ltt_ust_channel *uchan;
946 struct ltt_ust_session *usess;
947
948 usess = session->ust_session;
949
950 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
951 channel_name);
952 if (uchan == NULL) {
953 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
954 goto error;
955 }
956
957 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
958 if (ret != LTTNG_OK) {
959 goto error;
960 }
961
962 DBG3("Disable UST event %s in channel %s completed", event_name,
963 channel_name);
964 break;
965 }
966 #if 0
967 case LTTNG_DOMAIN_UST_EXEC_NAME:
968 case LTTNG_DOMAIN_UST_PID:
969 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
970 #endif
971 default:
972 ret = LTTNG_ERR_UND;
973 goto error;
974 }
975
976 ret = LTTNG_OK;
977
978 error:
979 rcu_read_unlock();
980 return ret;
981 }
982
983 /*
984 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
985 */
986 int cmd_disable_event_all(struct ltt_session *session, int domain,
987 char *channel_name)
988 {
989 int ret;
990
991 rcu_read_lock();
992
993 switch (domain) {
994 case LTTNG_DOMAIN_KERNEL:
995 {
996 struct ltt_kernel_session *ksess;
997 struct ltt_kernel_channel *kchan;
998
999 ksess = session->kernel_session;
1000
1001 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1002 if (kchan == NULL) {
1003 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1004 goto error;
1005 }
1006
1007 ret = event_kernel_disable_all(kchan);
1008 if (ret != LTTNG_OK) {
1009 goto error;
1010 }
1011
1012 kernel_wait_quiescent(kernel_tracer_fd);
1013 break;
1014 }
1015 case LTTNG_DOMAIN_UST:
1016 {
1017 struct ltt_ust_session *usess;
1018 struct ltt_ust_channel *uchan;
1019
1020 usess = session->ust_session;
1021
1022 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1023 channel_name);
1024 if (uchan == NULL) {
1025 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1026 goto error;
1027 }
1028
1029 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
1030 if (ret != 0) {
1031 goto error;
1032 }
1033
1034 DBG3("Disable all UST events in channel %s completed", channel_name);
1035
1036 break;
1037 }
1038 #if 0
1039 case LTTNG_DOMAIN_UST_EXEC_NAME:
1040 case LTTNG_DOMAIN_UST_PID:
1041 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1042 #endif
1043 default:
1044 ret = LTTNG_ERR_UND;
1045 goto error;
1046 }
1047
1048 ret = LTTNG_OK;
1049
1050 error:
1051 rcu_read_unlock();
1052 return ret;
1053 }
1054
1055 /*
1056 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1057 */
1058 int cmd_add_context(struct ltt_session *session, int domain,
1059 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1060 {
1061 int ret;
1062
1063 switch (domain) {
1064 case LTTNG_DOMAIN_KERNEL:
1065 assert(session->kernel_session);
1066
1067 if (session->kernel_session->channel_count == 0) {
1068 /* Create default channel */
1069 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1070 if (ret != LTTNG_OK) {
1071 goto error;
1072 }
1073 }
1074
1075 /* Add kernel context to kernel tracer */
1076 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1077 if (ret != LTTNG_OK) {
1078 goto error;
1079 }
1080 break;
1081 case LTTNG_DOMAIN_UST:
1082 {
1083 struct ltt_ust_session *usess = session->ust_session;
1084 assert(usess);
1085
1086 unsigned int chan_count =
1087 lttng_ht_get_count(usess->domain_global.channels);
1088 if (chan_count == 0) {
1089 struct lttng_channel *attr;
1090 /* Create default channel */
1091 attr = channel_new_default_attr(domain);
1092 if (attr == NULL) {
1093 ret = LTTNG_ERR_FATAL;
1094 goto error;
1095 }
1096
1097 ret = channel_ust_create(usess, domain, attr);
1098 if (ret != LTTNG_OK) {
1099 free(attr);
1100 goto error;
1101 }
1102 free(attr);
1103 }
1104
1105 ret = context_ust_add(usess, domain, ctx, channel_name);
1106 if (ret != LTTNG_OK) {
1107 goto error;
1108 }
1109 break;
1110 }
1111 #if 0
1112 case LTTNG_DOMAIN_UST_EXEC_NAME:
1113 case LTTNG_DOMAIN_UST_PID:
1114 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1115 #endif
1116 default:
1117 ret = LTTNG_ERR_UND;
1118 goto error;
1119 }
1120
1121 ret = LTTNG_OK;
1122
1123 error:
1124 return ret;
1125 }
1126
1127 /*
1128 * Command LTTNG_ENABLE_EVENT processed by the client thread.
1129 */
1130 int cmd_enable_event(struct ltt_session *session, int domain,
1131 char *channel_name, struct lttng_event *event,
1132 struct lttng_filter_bytecode *filter, int wpipe)
1133 {
1134 int ret, channel_created = 0;
1135 struct lttng_channel *attr;
1136
1137 assert(session);
1138 assert(event);
1139 assert(channel_name);
1140
1141 rcu_read_lock();
1142
1143 switch (domain) {
1144 case LTTNG_DOMAIN_KERNEL:
1145 {
1146 struct ltt_kernel_channel *kchan;
1147
1148 kchan = trace_kernel_get_channel_by_name(channel_name,
1149 session->kernel_session);
1150 if (kchan == NULL) {
1151 attr = channel_new_default_attr(domain);
1152 if (attr == NULL) {
1153 ret = LTTNG_ERR_FATAL;
1154 goto error;
1155 }
1156 strncpy(attr->name, channel_name, sizeof(attr->name));
1157
1158 ret = cmd_enable_channel(session, domain, attr, wpipe);
1159 if (ret != LTTNG_OK) {
1160 free(attr);
1161 goto error;
1162 }
1163 free(attr);
1164
1165 channel_created = 1;
1166 }
1167
1168 /* Get the newly created kernel channel pointer */
1169 kchan = trace_kernel_get_channel_by_name(channel_name,
1170 session->kernel_session);
1171 if (kchan == NULL) {
1172 /* This sould not happen... */
1173 ret = LTTNG_ERR_FATAL;
1174 goto error;
1175 }
1176
1177 ret = event_kernel_enable_tracepoint(kchan, event);
1178 if (ret != LTTNG_OK) {
1179 if (channel_created) {
1180 /* Let's not leak a useless channel. */
1181 kernel_destroy_channel(kchan);
1182 }
1183 goto error;
1184 }
1185
1186 kernel_wait_quiescent(kernel_tracer_fd);
1187 break;
1188 }
1189 case LTTNG_DOMAIN_UST:
1190 {
1191 struct ltt_ust_channel *uchan;
1192 struct ltt_ust_session *usess = session->ust_session;
1193
1194 assert(usess);
1195
1196 /* Get channel from global UST domain */
1197 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1198 channel_name);
1199 if (uchan == NULL) {
1200 /* Create default channel */
1201 attr = channel_new_default_attr(domain);
1202 if (attr == NULL) {
1203 ret = LTTNG_ERR_FATAL;
1204 goto error;
1205 }
1206 strncpy(attr->name, channel_name, sizeof(attr->name));
1207
1208 ret = cmd_enable_channel(session, domain, attr, wpipe);
1209 if (ret != LTTNG_OK) {
1210 free(attr);
1211 goto error;
1212 }
1213 free(attr);
1214
1215 /* Get the newly created channel reference back */
1216 uchan = trace_ust_find_channel_by_name(
1217 usess->domain_global.channels, channel_name);
1218 assert(uchan);
1219 }
1220
1221 /* At this point, the session and channel exist on the tracer */
1222 ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
1223 if (ret != LTTNG_OK) {
1224 goto error;
1225 }
1226 break;
1227 }
1228 #if 0
1229 case LTTNG_DOMAIN_UST_EXEC_NAME:
1230 case LTTNG_DOMAIN_UST_PID:
1231 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1232 #endif
1233 default:
1234 ret = LTTNG_ERR_UND;
1235 goto error;
1236 }
1237
1238 ret = LTTNG_OK;
1239
1240 error:
1241 rcu_read_unlock();
1242 return ret;
1243 }
1244
1245 /*
1246 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1247 */
1248 int cmd_enable_event_all(struct ltt_session *session, int domain,
1249 char *channel_name, int event_type,
1250 struct lttng_filter_bytecode *filter, int wpipe)
1251 {
1252 int ret;
1253 struct lttng_channel *attr;
1254
1255 assert(session);
1256 assert(channel_name);
1257
1258 rcu_read_lock();
1259
1260 switch (domain) {
1261 case LTTNG_DOMAIN_KERNEL:
1262 {
1263 struct ltt_kernel_channel *kchan;
1264
1265 assert(session->kernel_session);
1266
1267 kchan = trace_kernel_get_channel_by_name(channel_name,
1268 session->kernel_session);
1269 if (kchan == NULL) {
1270 /* Create default channel */
1271 attr = channel_new_default_attr(domain);
1272 if (attr == NULL) {
1273 ret = LTTNG_ERR_FATAL;
1274 goto error;
1275 }
1276 strncpy(attr->name, channel_name, sizeof(attr->name));
1277
1278 ret = cmd_enable_channel(session, domain, attr, wpipe);
1279 if (ret != LTTNG_OK) {
1280 free(attr);
1281 goto error;
1282 }
1283 free(attr);
1284
1285 /* Get the newly created kernel channel pointer */
1286 kchan = trace_kernel_get_channel_by_name(channel_name,
1287 session->kernel_session);
1288 assert(kchan);
1289 }
1290
1291 switch (event_type) {
1292 case LTTNG_EVENT_SYSCALL:
1293 ret = event_kernel_enable_all_syscalls(kchan, kernel_tracer_fd);
1294 break;
1295 case LTTNG_EVENT_TRACEPOINT:
1296 /*
1297 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1298 * events already registered to the channel.
1299 */
1300 ret = event_kernel_enable_all_tracepoints(kchan, kernel_tracer_fd);
1301 break;
1302 case LTTNG_EVENT_ALL:
1303 /* Enable syscalls and tracepoints */
1304 ret = event_kernel_enable_all(kchan, kernel_tracer_fd);
1305 break;
1306 default:
1307 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1308 goto error;
1309 }
1310
1311 /* Manage return value */
1312 if (ret != LTTNG_OK) {
1313 /*
1314 * On error, cmd_enable_channel call will take care of destroying
1315 * the created channel if it was needed.
1316 */
1317 goto error;
1318 }
1319
1320 kernel_wait_quiescent(kernel_tracer_fd);
1321 break;
1322 }
1323 case LTTNG_DOMAIN_UST:
1324 {
1325 struct ltt_ust_channel *uchan;
1326 struct ltt_ust_session *usess = session->ust_session;
1327
1328 assert(usess);
1329
1330 /* Get channel from global UST domain */
1331 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1332 channel_name);
1333 if (uchan == NULL) {
1334 /* Create default channel */
1335 attr = channel_new_default_attr(domain);
1336 if (attr == NULL) {
1337 ret = LTTNG_ERR_FATAL;
1338 goto error;
1339 }
1340 strncpy(attr->name, channel_name, sizeof(attr->name));
1341
1342 ret = cmd_enable_channel(session, domain, attr, wpipe);
1343 if (ret != LTTNG_OK) {
1344 free(attr);
1345 goto error;
1346 }
1347 free(attr);
1348
1349 /* Get the newly created channel reference back */
1350 uchan = trace_ust_find_channel_by_name(
1351 usess->domain_global.channels, channel_name);
1352 assert(uchan);
1353 }
1354
1355 /* At this point, the session and channel exist on the tracer */
1356
1357 switch (event_type) {
1358 case LTTNG_EVENT_ALL:
1359 case LTTNG_EVENT_TRACEPOINT:
1360 ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
1361 filter);
1362 if (ret != LTTNG_OK) {
1363 goto error;
1364 }
1365 break;
1366 default:
1367 ret = LTTNG_ERR_UST_ENABLE_FAIL;
1368 goto error;
1369 }
1370
1371 /* Manage return value */
1372 if (ret != LTTNG_OK) {
1373 goto error;
1374 }
1375
1376 break;
1377 }
1378 #if 0
1379 case LTTNG_DOMAIN_UST_EXEC_NAME:
1380 case LTTNG_DOMAIN_UST_PID:
1381 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1382 #endif
1383 default:
1384 ret = LTTNG_ERR_UND;
1385 goto error;
1386 }
1387
1388 ret = LTTNG_OK;
1389
1390 error:
1391 rcu_read_unlock();
1392 return ret;
1393 }
1394
1395
1396 /*
1397 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1398 */
1399 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1400 {
1401 int ret;
1402 ssize_t nb_events = 0;
1403
1404 switch (domain) {
1405 case LTTNG_DOMAIN_KERNEL:
1406 nb_events = kernel_list_events(kernel_tracer_fd, events);
1407 if (nb_events < 0) {
1408 ret = LTTNG_ERR_KERN_LIST_FAIL;
1409 goto error;
1410 }
1411 break;
1412 case LTTNG_DOMAIN_UST:
1413 nb_events = ust_app_list_events(events);
1414 if (nb_events < 0) {
1415 ret = LTTNG_ERR_UST_LIST_FAIL;
1416 goto error;
1417 }
1418 break;
1419 default:
1420 ret = LTTNG_ERR_UND;
1421 goto error;
1422 }
1423
1424 return nb_events;
1425
1426 error:
1427 /* Return negative value to differentiate return code */
1428 return -ret;
1429 }
1430
1431 /*
1432 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1433 */
1434 ssize_t cmd_list_tracepoint_fields(int domain,
1435 struct lttng_event_field **fields)
1436 {
1437 int ret;
1438 ssize_t nb_fields = 0;
1439
1440 switch (domain) {
1441 case LTTNG_DOMAIN_UST:
1442 nb_fields = ust_app_list_event_fields(fields);
1443 if (nb_fields < 0) {
1444 ret = LTTNG_ERR_UST_LIST_FAIL;
1445 goto error;
1446 }
1447 break;
1448 case LTTNG_DOMAIN_KERNEL:
1449 default: /* fall-through */
1450 ret = LTTNG_ERR_UND;
1451 goto error;
1452 }
1453
1454 return nb_fields;
1455
1456 error:
1457 /* Return negative value to differentiate return code */
1458 return -ret;
1459 }
1460
1461 /*
1462 * Command LTTNG_START_TRACE processed by the client thread.
1463 */
1464 int cmd_start_trace(struct ltt_session *session)
1465 {
1466 int ret;
1467 struct ltt_kernel_session *ksession;
1468 struct ltt_ust_session *usess;
1469
1470 assert(session);
1471
1472 /* Ease our life a bit ;) */
1473 ksession = session->kernel_session;
1474 usess = session->ust_session;
1475
1476 if (session->enabled) {
1477 /* Already started. */
1478 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1479 goto error;
1480 }
1481
1482 session->enabled = 1;
1483
1484 ret = setup_relayd(session);
1485 if (ret != LTTNG_OK) {
1486 ERR("Error setting up relayd for session %s", session->name);
1487 goto error;
1488 }
1489
1490 /* Kernel tracing */
1491 if (ksession != NULL) {
1492 ret = start_kernel_session(ksession, kernel_tracer_fd);
1493 if (ret != LTTNG_OK) {
1494 goto error;
1495 }
1496 }
1497
1498 /* Flag session that trace should start automatically */
1499 if (usess) {
1500 usess->start_trace = 1;
1501
1502 ret = ust_app_start_trace_all(usess);
1503 if (ret < 0) {
1504 ret = LTTNG_ERR_UST_START_FAIL;
1505 goto error;
1506 }
1507 }
1508
1509 session->started = 1;
1510
1511 ret = LTTNG_OK;
1512
1513 error:
1514 return ret;
1515 }
1516
1517 /*
1518 * Command LTTNG_STOP_TRACE processed by the client thread.
1519 */
1520 int cmd_stop_trace(struct ltt_session *session)
1521 {
1522 int ret;
1523 struct ltt_kernel_channel *kchan;
1524 struct ltt_kernel_session *ksession;
1525 struct ltt_ust_session *usess;
1526
1527 assert(session);
1528
1529 /* Short cut */
1530 ksession = session->kernel_session;
1531 usess = session->ust_session;
1532
1533 if (!session->enabled) {
1534 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1535 goto error;
1536 }
1537
1538 session->enabled = 0;
1539
1540 /* Kernel tracer */
1541 if (ksession) {
1542 DBG("Stop kernel tracing");
1543
1544 /* Flush metadata if exist */
1545 if (ksession->metadata_stream_fd >= 0) {
1546 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1547 if (ret < 0) {
1548 ERR("Kernel metadata flush failed");
1549 }
1550 }
1551
1552 /* Flush all buffers before stopping */
1553 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1554 ret = kernel_flush_buffer(kchan);
1555 if (ret < 0) {
1556 ERR("Kernel flush buffer error");
1557 }
1558 }
1559
1560 ret = kernel_stop_session(ksession);
1561 if (ret < 0) {
1562 ret = LTTNG_ERR_KERN_STOP_FAIL;
1563 goto error;
1564 }
1565
1566 kernel_wait_quiescent(kernel_tracer_fd);
1567
1568 ksession->started = 0;
1569 }
1570
1571 if (usess) {
1572 usess->start_trace = 0;
1573
1574 ret = ust_app_stop_trace_all(usess);
1575 if (ret < 0) {
1576 ret = LTTNG_ERR_UST_STOP_FAIL;
1577 goto error;
1578 }
1579 }
1580
1581 session->started = 0;
1582
1583 ret = LTTNG_OK;
1584
1585 error:
1586 return ret;
1587 }
1588
1589 /*
1590 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1591 */
1592 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1593 size_t nb_uri, struct lttng_uri *uris)
1594 {
1595 int ret, i;
1596 struct ltt_kernel_session *ksess = session->kernel_session;
1597 struct ltt_ust_session *usess = session->ust_session;
1598 struct consumer_output *consumer = NULL;
1599
1600 assert(session);
1601 assert(uris);
1602 assert(nb_uri > 0);
1603
1604 /* Can't enable consumer after session started. */
1605 if (session->enabled) {
1606 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1607 goto error;
1608 }
1609
1610 /*
1611 * This case switch makes sure the domain session has a temporary consumer
1612 * so the URL can be set.
1613 */
1614 switch (domain) {
1615 case 0:
1616 /* Code flow error. A session MUST always have a consumer object */
1617 assert(session->consumer);
1618 /*
1619 * The URL will be added to the tracing session consumer instead of a
1620 * specific domain consumer.
1621 */
1622 consumer = session->consumer;
1623 break;
1624 case LTTNG_DOMAIN_KERNEL:
1625 /* Code flow error if we don't have a kernel session here. */
1626 assert(ksess);
1627
1628 /* Create consumer output if none exists */
1629 consumer = ksess->tmp_consumer;
1630 if (consumer == NULL) {
1631 consumer = consumer_copy_output(ksess->consumer);
1632 if (consumer == NULL) {
1633 ret = LTTNG_ERR_FATAL;
1634 goto error;
1635 }
1636 /* Trash the consumer subdir, we are about to set a new one. */
1637 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1638 ksess->tmp_consumer = consumer;
1639 }
1640
1641 break;
1642 case LTTNG_DOMAIN_UST:
1643 /* Code flow error if we don't have a kernel session here. */
1644 assert(usess);
1645
1646 /* Create consumer output if none exists */
1647 consumer = usess->tmp_consumer;
1648 if (consumer == NULL) {
1649 consumer = consumer_copy_output(usess->consumer);
1650 if (consumer == NULL) {
1651 ret = LTTNG_ERR_FATAL;
1652 goto error;
1653 }
1654 /* Trash the consumer subdir, we are about to set a new one. */
1655 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1656 usess->tmp_consumer = consumer;
1657 }
1658
1659 break;
1660 }
1661
1662 for (i = 0; i < nb_uri; i++) {
1663 struct consumer_socket *socket;
1664 struct lttng_ht_iter iter;
1665
1666 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1667 if (ret < 0) {
1668 goto error;
1669 }
1670
1671 /*
1672 * Don't send relayd socket if URI is NOT remote or if the relayd
1673 * socket for the session was already sent.
1674 */
1675 if (uris[i].dtype == LTTNG_DST_PATH ||
1676 (uris[i].stype == LTTNG_STREAM_CONTROL &&
1677 consumer->dst.net.control_sock_sent) ||
1678 (uris[i].stype == LTTNG_STREAM_DATA &&
1679 consumer->dst.net.data_sock_sent)) {
1680 continue;
1681 }
1682
1683 /* Try to send relayd URI to the consumer if exist. */
1684 rcu_read_lock();
1685 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1686 socket, node.node) {
1687
1688 /* A socket in the HT should never have a negative fd */
1689 assert(socket->fd >= 0);
1690
1691 pthread_mutex_lock(socket->lock);
1692 ret = send_consumer_relayd_socket(domain, session, &uris[i],
1693 consumer, socket);
1694 pthread_mutex_unlock(socket->lock);
1695 if (ret != LTTNG_OK) {
1696 rcu_read_unlock();
1697 goto error;
1698 }
1699 }
1700 rcu_read_unlock();
1701 }
1702
1703 /* All good! */
1704 ret = LTTNG_OK;
1705
1706 error:
1707 return ret;
1708 }
1709
1710 /*
1711 * Command LTTNG_CREATE_SESSION processed by the client thread.
1712 */
1713 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1714 size_t nb_uri, lttng_sock_cred *creds)
1715 {
1716 int ret;
1717 char *path = NULL;
1718 struct ltt_session *session;
1719
1720 assert(name);
1721
1722 /*
1723 * Verify if the session already exist
1724 *
1725 * XXX: There is no need for the session lock list here since the caller
1726 * (process_client_msg) is holding it. We might want to change that so a
1727 * single command does not lock the entire session list.
1728 */
1729 session = session_find_by_name(name);
1730 if (session != NULL) {
1731 ret = LTTNG_ERR_EXIST_SESS;
1732 goto find_error;
1733 }
1734
1735 /* Create tracing session in the registry */
1736 ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1737 LTTNG_SOCK_GET_GID_CRED(creds));
1738 if (ret != LTTNG_OK) {
1739 goto session_error;
1740 }
1741
1742 /*
1743 * Get the newly created session pointer back
1744 *
1745 * XXX: There is no need for the session lock list here since the caller
1746 * (process_client_msg) is holding it. We might want to change that so a
1747 * single command does not lock the entire session list.
1748 */
1749 session = session_find_by_name(name);
1750 assert(session);
1751
1752 /* Create default consumer output for the session not yet created. */
1753 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1754 if (session->consumer == NULL) {
1755 ret = LTTNG_ERR_FATAL;
1756 goto consumer_error;
1757 }
1758
1759 /*
1760 * This means that the lttng_create_session call was called with the _path_
1761 * argument set to NULL.
1762 */
1763 if (uris == NULL) {
1764 /*
1765 * At this point, we'll skip the consumer URI setup and create a
1766 * session with a NULL path which will flag the session to NOT spawn a
1767 * consumer.
1768 */
1769 DBG("Create session %s with NO uri, skipping consumer setup", name);
1770 goto end;
1771 }
1772
1773 session->start_consumer = 1;
1774
1775 ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1776 if (ret != LTTNG_OK) {
1777 goto consumer_error;
1778 }
1779
1780 session->consumer->enabled = 1;
1781
1782 end:
1783 return LTTNG_OK;
1784
1785 consumer_error:
1786 session_destroy(session);
1787 session_error:
1788 find_error:
1789 return ret;
1790 }
1791
1792 /*
1793 * Command LTTNG_DESTROY_SESSION processed by the client thread.
1794 */
1795 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1796 {
1797 int ret;
1798 struct ltt_ust_session *usess;
1799 struct ltt_kernel_session *ksess;
1800
1801 /* Safety net */
1802 assert(session);
1803
1804 usess = session->ust_session;
1805 ksess = session->kernel_session;
1806
1807 /* Clean kernel session teardown */
1808 kernel_destroy_session(ksess);
1809
1810 /* UST session teardown */
1811 if (usess) {
1812 /* Close any relayd session */
1813 consumer_output_send_destroy_relayd(usess->consumer);
1814
1815 /* Destroy every UST application related to this session. */
1816 ret = ust_app_destroy_trace_all(usess);
1817 if (ret) {
1818 ERR("Error in ust_app_destroy_trace_all");
1819 }
1820
1821 /* Clean up the rest. */
1822 trace_ust_destroy_session(usess);
1823 }
1824
1825 /*
1826 * Must notify the kernel thread here to update it's poll set in order to
1827 * remove the channel(s)' fd just destroyed.
1828 */
1829 ret = notify_thread_pipe(wpipe);
1830 if (ret < 0) {
1831 PERROR("write kernel poll pipe");
1832 }
1833
1834 ret = session_destroy(session);
1835
1836 return ret;
1837 }
1838
1839 /*
1840 * Command LTTNG_CALIBRATE processed by the client thread.
1841 */
1842 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1843 {
1844 int ret;
1845
1846 switch (domain) {
1847 case LTTNG_DOMAIN_KERNEL:
1848 {
1849 struct lttng_kernel_calibrate kcalibrate;
1850
1851 kcalibrate.type = calibrate->type;
1852 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1853 if (ret < 0) {
1854 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1855 goto error;
1856 }
1857 break;
1858 }
1859 case LTTNG_DOMAIN_UST:
1860 {
1861 struct lttng_ust_calibrate ucalibrate;
1862
1863 ucalibrate.type = calibrate->type;
1864 ret = ust_app_calibrate_glb(&ucalibrate);
1865 if (ret < 0) {
1866 ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1867 goto error;
1868 }
1869 break;
1870 }
1871 default:
1872 ret = LTTNG_ERR_UND;
1873 goto error;
1874 }
1875
1876 ret = LTTNG_OK;
1877
1878 error:
1879 return ret;
1880 }
1881
1882 /*
1883 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1884 */
1885 int cmd_register_consumer(struct ltt_session *session, int domain,
1886 const char *sock_path, struct consumer_data *cdata)
1887 {
1888 int ret, sock;
1889 struct consumer_socket *socket;
1890
1891 assert(session);
1892 assert(cdata);
1893 assert(sock_path);
1894
1895 switch (domain) {
1896 case LTTNG_DOMAIN_KERNEL:
1897 {
1898 struct ltt_kernel_session *ksess = session->kernel_session;
1899
1900 assert(ksess);
1901
1902 /* Can't register a consumer if there is already one */
1903 if (ksess->consumer_fds_sent != 0) {
1904 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1905 goto error;
1906 }
1907
1908 sock = lttcomm_connect_unix_sock(sock_path);
1909 if (sock < 0) {
1910 ret = LTTNG_ERR_CONNECT_FAIL;
1911 goto error;
1912 }
1913
1914 socket = consumer_allocate_socket(sock);
1915 if (socket == NULL) {
1916 ret = close(sock);
1917 if (ret < 0) {
1918 PERROR("close register consumer");
1919 }
1920 ret = LTTNG_ERR_FATAL;
1921 goto error;
1922 }
1923
1924 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1925 if (socket->lock == NULL) {
1926 PERROR("zmalloc pthread mutex");
1927 ret = LTTNG_ERR_FATAL;
1928 goto error;
1929 }
1930 pthread_mutex_init(socket->lock, NULL);
1931 socket->registered = 1;
1932
1933 rcu_read_lock();
1934 consumer_add_socket(socket, ksess->consumer);
1935 rcu_read_unlock();
1936
1937 pthread_mutex_lock(&cdata->pid_mutex);
1938 cdata->pid = -1;
1939 pthread_mutex_unlock(&cdata->pid_mutex);
1940
1941 break;
1942 }
1943 default:
1944 /* TODO: Userspace tracing */
1945 ret = LTTNG_ERR_UND;
1946 goto error;
1947 }
1948
1949 ret = LTTNG_OK;
1950
1951 error:
1952 return ret;
1953 }
1954
1955 /*
1956 * Command LTTNG_LIST_DOMAINS processed by the client thread.
1957 */
1958 ssize_t cmd_list_domains(struct ltt_session *session,
1959 struct lttng_domain **domains)
1960 {
1961 int ret, index = 0;
1962 ssize_t nb_dom = 0;
1963
1964 if (session->kernel_session != NULL) {
1965 DBG3("Listing domains found kernel domain");
1966 nb_dom++;
1967 }
1968
1969 if (session->ust_session != NULL) {
1970 DBG3("Listing domains found UST global domain");
1971 nb_dom++;
1972 }
1973
1974 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1975 if (*domains == NULL) {
1976 ret = LTTNG_ERR_FATAL;
1977 goto error;
1978 }
1979
1980 if (session->kernel_session != NULL) {
1981 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1982 index++;
1983 }
1984
1985 if (session->ust_session != NULL) {
1986 (*domains)[index].type = LTTNG_DOMAIN_UST;
1987 index++;
1988 }
1989
1990 return nb_dom;
1991
1992 error:
1993 /* Return negative value to differentiate return code */
1994 return -ret;
1995 }
1996
1997
1998 /*
1999 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2000 */
2001 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2002 struct lttng_channel **channels)
2003 {
2004 int ret;
2005 ssize_t nb_chan = 0;
2006
2007 switch (domain) {
2008 case LTTNG_DOMAIN_KERNEL:
2009 if (session->kernel_session != NULL) {
2010 nb_chan = session->kernel_session->channel_count;
2011 }
2012 DBG3("Number of kernel channels %zd", nb_chan);
2013 if (nb_chan <= 0) {
2014 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
2015 }
2016 break;
2017 case LTTNG_DOMAIN_UST:
2018 if (session->ust_session != NULL) {
2019 nb_chan = lttng_ht_get_count(
2020 session->ust_session->domain_global.channels);
2021 }
2022 DBG3("Number of UST global channels %zd", nb_chan);
2023 if (nb_chan <= 0) {
2024 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2025 }
2026 break;
2027 default:
2028 *channels = NULL;
2029 ret = LTTNG_ERR_UND;
2030 goto error;
2031 }
2032
2033 if (nb_chan > 0) {
2034 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2035 if (*channels == NULL) {
2036 ret = LTTNG_ERR_FATAL;
2037 goto error;
2038 }
2039
2040 list_lttng_channels(domain, session, *channels);
2041 } else {
2042 *channels = NULL;
2043 /* Ret value was set in the domain switch case */
2044 goto error;
2045 }
2046
2047 return nb_chan;
2048
2049 error:
2050 /* Return negative value to differentiate return code */
2051 return -ret;
2052 }
2053
2054 /*
2055 * Command LTTNG_LIST_EVENTS processed by the client thread.
2056 */
2057 ssize_t cmd_list_events(int domain, struct ltt_session *session,
2058 char *channel_name, struct lttng_event **events)
2059 {
2060 int ret = 0;
2061 ssize_t nb_event = 0;
2062
2063 switch (domain) {
2064 case LTTNG_DOMAIN_KERNEL:
2065 if (session->kernel_session != NULL) {
2066 nb_event = list_lttng_kernel_events(channel_name,
2067 session->kernel_session, events);
2068 }
2069 break;
2070 case LTTNG_DOMAIN_UST:
2071 {
2072 if (session->ust_session != NULL) {
2073 nb_event = list_lttng_ust_global_events(channel_name,
2074 &session->ust_session->domain_global, events);
2075 }
2076 break;
2077 }
2078 default:
2079 ret = LTTNG_ERR_UND;
2080 goto error;
2081 }
2082
2083 return nb_event;
2084
2085 error:
2086 /* Return negative value to differentiate return code */
2087 return -ret;
2088 }
2089
2090 /*
2091 * Using the session list, filled a lttng_session array to send back to the
2092 * client for session listing.
2093 *
2094 * The session list lock MUST be acquired before calling this function. Use
2095 * session_lock_list() and session_unlock_list().
2096 */
2097 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2098 gid_t gid)
2099 {
2100 int ret;
2101 unsigned int i = 0;
2102 struct ltt_session *session;
2103 struct ltt_session_list *list = session_get_list();
2104
2105 DBG("Getting all available session for UID %d GID %d",
2106 uid, gid);
2107 /*
2108 * Iterate over session list and append data after the control struct in
2109 * the buffer.
2110 */
2111 cds_list_for_each_entry(session, &list->head, list) {
2112 /*
2113 * Only list the sessions the user can control.
2114 */
2115 if (!session_access_ok(session, uid, gid)) {
2116 continue;
2117 }
2118
2119 struct ltt_kernel_session *ksess = session->kernel_session;
2120 struct ltt_ust_session *usess = session->ust_session;
2121
2122 if (session->consumer->type == CONSUMER_DST_NET ||
2123 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2124 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2125 ret = build_network_session_path(sessions[i].path,
2126 sizeof(session[i].path), session);
2127 } else {
2128 ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2129 session->consumer->dst.trace_path);
2130 }
2131 if (ret < 0) {
2132 PERROR("snprintf session path");
2133 continue;
2134 }
2135
2136 strncpy(sessions[i].name, session->name, NAME_MAX);
2137 sessions[i].name[NAME_MAX - 1] = '\0';
2138 sessions[i].enabled = session->enabled;
2139 i++;
2140 }
2141 }
2142
2143 /*
2144 * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2145 */
2146 int cmd_disable_consumer(int domain, struct ltt_session *session)
2147 {
2148 int ret;
2149 struct ltt_kernel_session *ksess = session->kernel_session;
2150 struct ltt_ust_session *usess = session->ust_session;
2151 struct consumer_output *consumer;
2152
2153 assert(session);
2154
2155 if (session->enabled) {
2156 /* Can't disable consumer on an already started session */
2157 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2158 goto error;
2159 }
2160
2161 if (!session->start_consumer) {
2162 ret = LTTNG_ERR_NO_CONSUMER;
2163 goto error;
2164 }
2165
2166 switch (domain) {
2167 case 0:
2168 DBG("Disable tracing session %s consumer", session->name);
2169 consumer = session->consumer;
2170 break;
2171 case LTTNG_DOMAIN_KERNEL:
2172 /* Code flow error if we don't have a kernel session here. */
2173 assert(ksess);
2174
2175 DBG("Disabling kernel consumer");
2176 consumer = ksess->consumer;
2177
2178 break;
2179 case LTTNG_DOMAIN_UST:
2180 /* Code flow error if we don't have a UST session here. */
2181 assert(usess);
2182
2183 DBG("Disabling UST consumer");
2184 consumer = usess->consumer;
2185
2186 break;
2187 default:
2188 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2189 goto error;
2190 }
2191
2192 if (consumer) {
2193 consumer->enabled = 0;
2194 /* Success at this point */
2195 ret = LTTNG_OK;
2196 } else {
2197 ret = LTTNG_ERR_NO_CONSUMER;
2198 }
2199
2200 error:
2201 return ret;
2202 }
2203
2204 /*
2205 * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2206 */
2207 int cmd_enable_consumer(int domain, struct ltt_session *session)
2208 {
2209 int ret;
2210 struct ltt_kernel_session *ksess = session->kernel_session;
2211 struct ltt_ust_session *usess = session->ust_session;
2212 struct consumer_output *consumer = NULL;
2213
2214 assert(session);
2215
2216 /* Can't enable consumer after session started. */
2217 if (session->enabled) {
2218 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2219 goto error;
2220 }
2221
2222 switch (domain) {
2223 case 0:
2224 assert(session->consumer);
2225 consumer = session->consumer;
2226 break;
2227 case LTTNG_DOMAIN_KERNEL:
2228 /* Code flow error if we don't have a kernel session here. */
2229 assert(ksess);
2230
2231 /*
2232 * Check if we have already sent fds to the consumer. In that case,
2233 * the enable-consumer command can't be used because a start trace
2234 * had previously occured.
2235 */
2236 if (ksess->consumer_fds_sent) {
2237 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2238 goto error;
2239 }
2240
2241 consumer = ksess->tmp_consumer;
2242 if (consumer == NULL) {
2243 ret = LTTNG_OK;
2244 /* No temp. consumer output exists. Using the current one. */
2245 DBG3("No temporary consumer. Using default");
2246 consumer = ksess->consumer;
2247 goto error;
2248 }
2249
2250 switch (consumer->type) {
2251 case CONSUMER_DST_LOCAL:
2252 DBG2("Consumer output is local. Creating directory(ies)");
2253
2254 /* Create directory(ies) */
2255 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2256 S_IRWXU | S_IRWXG, session->uid, session->gid);
2257 if (ret < 0) {
2258 if (ret != -EEXIST) {
2259 ERR("Trace directory creation error");
2260 ret = LTTNG_ERR_FATAL;
2261 goto error;
2262 }
2263 }
2264 break;
2265 case CONSUMER_DST_NET:
2266 DBG2("Consumer output is network. Validating URIs");
2267 /* Validate if we have both control and data path set. */
2268 if (!consumer->dst.net.control_isset) {
2269 ret = LTTNG_ERR_URL_CTRL_MISS;
2270 goto error;
2271 }
2272
2273 if (!consumer->dst.net.data_isset) {
2274 ret = LTTNG_ERR_URL_DATA_MISS;
2275 goto error;
2276 }
2277
2278 /* Check established network session state */
2279 if (session->net_handle == 0) {
2280 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2281 ERR("Session network handle is not set on enable-consumer");
2282 goto error;
2283 }
2284
2285 break;
2286 }
2287
2288 /*
2289 * @session-lock
2290 * This is race free for now since the session lock is acquired before
2291 * ending up in this function. No other threads can access this kernel
2292 * session without this lock hence freeing the consumer output object
2293 * is valid.
2294 */
2295 rcu_read_lock();
2296 /* Destroy current consumer. We are about to replace it */
2297 consumer_destroy_output(ksess->consumer);
2298 rcu_read_unlock();
2299 ksess->consumer = consumer;
2300 ksess->tmp_consumer = NULL;
2301
2302 break;
2303 case LTTNG_DOMAIN_UST:
2304 /* Code flow error if we don't have a UST session here. */
2305 assert(usess);
2306
2307 /*
2308 * Check if we have already sent fds to the consumer. In that case,
2309 * the enable-consumer command can't be used because a start trace
2310 * had previously occured.
2311 */
2312 if (usess->start_trace) {
2313 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2314 goto error;
2315 }
2316
2317 consumer = usess->tmp_consumer;
2318 if (consumer == NULL) {
2319 ret = LTTNG_OK;
2320 /* No temp. consumer output exists. Using the current one. */
2321 DBG3("No temporary consumer. Using default");
2322 consumer = usess->consumer;
2323 goto error;
2324 }
2325
2326 switch (consumer->type) {
2327 case CONSUMER_DST_LOCAL:
2328 DBG2("Consumer output is local. Creating directory(ies)");
2329
2330 /* Create directory(ies) */
2331 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2332 S_IRWXU | S_IRWXG, session->uid, session->gid);
2333 if (ret < 0) {
2334 if (ret != -EEXIST) {
2335 ERR("Trace directory creation error");
2336 ret = LTTNG_ERR_FATAL;
2337 goto error;
2338 }
2339 }
2340 break;
2341 case CONSUMER_DST_NET:
2342 DBG2("Consumer output is network. Validating URIs");
2343 /* Validate if we have both control and data path set. */
2344 if (!consumer->dst.net.control_isset) {
2345 ret = LTTNG_ERR_URL_CTRL_MISS;
2346 goto error;
2347 }
2348
2349 if (!consumer->dst.net.data_isset) {
2350 ret = LTTNG_ERR_URL_DATA_MISS;
2351 goto error;
2352 }
2353
2354 /* Check established network session state */
2355 if (session->net_handle == 0) {
2356 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2357 DBG2("Session network handle is not set on enable-consumer");
2358 goto error;
2359 }
2360
2361 if (consumer->net_seq_index == -1) {
2362 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2363 DBG2("Network index is not set on the consumer");
2364 goto error;
2365 }
2366
2367 break;
2368 }
2369
2370 /*
2371 * @session-lock
2372 * This is race free for now since the session lock is acquired before
2373 * ending up in this function. No other threads can access this kernel
2374 * session without this lock hence freeing the consumer output object
2375 * is valid.
2376 */
2377 rcu_read_lock();
2378 /* Destroy current consumer. We are about to replace it */
2379 consumer_destroy_output(usess->consumer);
2380 rcu_read_unlock();
2381 usess->consumer = consumer;
2382 usess->tmp_consumer = NULL;
2383
2384 break;
2385 }
2386
2387 session->start_consumer = 1;
2388
2389 /* Enable it */
2390 if (consumer) {
2391 consumer->enabled = 1;
2392 /* Success at this point */
2393 ret = LTTNG_OK;
2394 } else {
2395 /* Should not really happend... */
2396 ret = LTTNG_ERR_NO_CONSUMER;
2397 }
2398
2399 error:
2400 return ret;
2401 }
2402
2403 /*
2404 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
2405 * ready for trace analysis (or anykind of reader) or else 1 for pending data.
2406 */
2407 int cmd_data_pending(struct ltt_session *session)
2408 {
2409 int ret;
2410 struct ltt_kernel_session *ksess = session->kernel_session;
2411 struct ltt_ust_session *usess = session->ust_session;
2412
2413 assert(session);
2414
2415 /* Session MUST be stopped to ask for data availability. */
2416 if (session->enabled) {
2417 ret = LTTNG_ERR_SESSION_STARTED;
2418 goto error;
2419 }
2420
2421 if (ksess && ksess->consumer) {
2422 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
2423 if (ret == 1) {
2424 /* Data is still being extracted for the kernel. */
2425 goto error;
2426 }
2427 }
2428
2429 if (usess && usess->consumer) {
2430 ret = consumer_is_data_pending(usess->id, usess->consumer);
2431 if (ret == 1) {
2432 /* Data is still being extracted for the kernel. */
2433 goto error;
2434 }
2435 }
2436
2437 /* Data is ready to be read by a viewer */
2438 ret = 0;
2439
2440 error:
2441 return ret;
2442 }
2443
2444 /*
2445 * Init command subsystem.
2446 */
2447 void cmd_init(void)
2448 {
2449 /*
2450 * Set network sequence index to 1 for streams to match a relayd socket on
2451 * the consumer side.
2452 */
2453 uatomic_set(&relayd_net_seq_idx, 1);
2454
2455 DBG("Command subsystem initialized");
2456 }
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