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