relayd: Implement custom EfficiOS session clear
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <lttng/ust-ctl.h>
23 #include <poll.h>
24 #include <pthread.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/mman.h>
28 #include <sys/socket.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31 #include <inttypes.h>
32 #include <unistd.h>
33 #include <urcu/list.h>
34 #include <signal.h>
35
36 #include <bin/lttng-consumerd/health-consumerd.h>
37 #include <common/common.h>
38 #include <common/sessiond-comm/sessiond-comm.h>
39 #include <common/relayd/relayd.h>
40 #include <common/compat/fcntl.h>
41 #include <common/compat/endian.h>
42 #include <common/consumer/consumer-metadata-cache.h>
43 #include <common/consumer/consumer-stream.h>
44 #include <common/consumer/consumer-timer.h>
45 #include <common/utils.h>
46 #include <common/index/index.h>
47
48 #include "ust-consumer.h"
49
50 #define INT_MAX_STR_LEN 12 /* includes \0 */
51
52 extern struct lttng_consumer_global_data consumer_data;
53 extern int consumer_poll_timeout;
54
55 /*
56 * Free channel object and all streams associated with it. This MUST be used
57 * only and only if the channel has _NEVER_ been added to the global channel
58 * hash table.
59 */
60 static void destroy_channel(struct lttng_consumer_channel *channel)
61 {
62 struct lttng_consumer_stream *stream, *stmp;
63
64 assert(channel);
65
66 DBG("UST consumer cleaning stream list");
67
68 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
69 send_node) {
70
71 health_code_update();
72
73 cds_list_del(&stream->send_node);
74 ustctl_destroy_stream(stream->ustream);
75 free(stream);
76 }
77
78 /*
79 * If a channel is available meaning that was created before the streams
80 * were, delete it.
81 */
82 if (channel->uchan) {
83 lttng_ustconsumer_del_channel(channel);
84 lttng_ustconsumer_free_channel(channel);
85 }
86 free(channel);
87 }
88
89 /*
90 * Add channel to internal consumer state.
91 *
92 * Returns 0 on success or else a negative value.
93 */
94 static int add_channel(struct lttng_consumer_channel *channel,
95 struct lttng_consumer_local_data *ctx)
96 {
97 int ret = 0;
98
99 assert(channel);
100 assert(ctx);
101
102 if (ctx->on_recv_channel != NULL) {
103 ret = ctx->on_recv_channel(channel);
104 if (ret == 0) {
105 ret = consumer_add_channel(channel, ctx);
106 } else if (ret < 0) {
107 /* Most likely an ENOMEM. */
108 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
109 goto error;
110 }
111 } else {
112 ret = consumer_add_channel(channel, ctx);
113 }
114
115 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
116
117 error:
118 return ret;
119 }
120
121 /*
122 * Allocate and return a consumer channel object.
123 */
124 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
125 const char *pathname, const char *name, uid_t uid, gid_t gid,
126 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
127 uint64_t tracefile_size, uint64_t tracefile_count,
128 uint64_t session_id_per_pid, unsigned int monitor,
129 unsigned int live_timer_interval,
130 const char *root_shm_path, const char *shm_path)
131 {
132 assert(pathname);
133 assert(name);
134
135 return consumer_allocate_channel(key, session_id, pathname, name, uid,
136 gid, relayd_id, output, tracefile_size,
137 tracefile_count, session_id_per_pid, monitor,
138 live_timer_interval, root_shm_path, shm_path);
139 }
140
141 /*
142 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
143 * error value if applicable is set in it else it is kept untouched.
144 *
145 * Return NULL on error else the newly allocated stream object.
146 */
147 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
148 struct lttng_consumer_channel *channel,
149 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
150 {
151 int alloc_ret;
152 struct lttng_consumer_stream *stream = NULL;
153
154 assert(channel);
155 assert(ctx);
156
157 stream = consumer_allocate_stream(channel->key,
158 key,
159 LTTNG_CONSUMER_ACTIVE_STREAM,
160 channel->name,
161 channel->uid,
162 channel->gid,
163 channel->relayd_id,
164 channel->session_id,
165 cpu,
166 &alloc_ret,
167 channel->type,
168 channel->monitor);
169 if (stream == NULL) {
170 switch (alloc_ret) {
171 case -ENOENT:
172 /*
173 * We could not find the channel. Can happen if cpu hotplug
174 * happens while tearing down.
175 */
176 DBG3("Could not find channel");
177 break;
178 case -ENOMEM:
179 case -EINVAL:
180 default:
181 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
182 break;
183 }
184 goto error;
185 }
186
187 stream->chan = channel;
188
189 error:
190 if (_alloc_ret) {
191 *_alloc_ret = alloc_ret;
192 }
193 return stream;
194 }
195
196 /*
197 * Send the given stream pointer to the corresponding thread.
198 *
199 * Returns 0 on success else a negative value.
200 */
201 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
202 struct lttng_consumer_local_data *ctx)
203 {
204 int ret;
205 struct lttng_pipe *stream_pipe;
206
207 /* Get the right pipe where the stream will be sent. */
208 if (stream->metadata_flag) {
209 ret = consumer_add_metadata_stream(stream);
210 if (ret) {
211 ERR("Consumer add metadata stream %" PRIu64 " failed.",
212 stream->key);
213 goto error;
214 }
215 stream_pipe = ctx->consumer_metadata_pipe;
216 } else {
217 ret = consumer_add_data_stream(stream);
218 if (ret) {
219 ERR("Consumer add stream %" PRIu64 " failed.",
220 stream->key);
221 goto error;
222 }
223 stream_pipe = ctx->consumer_data_pipe;
224 }
225
226 /*
227 * From this point on, the stream's ownership has been moved away from
228 * the channel and becomes globally visible.
229 */
230 stream->globally_visible = 1;
231
232 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
233 if (ret < 0) {
234 ERR("Consumer write %s stream to pipe %d",
235 stream->metadata_flag ? "metadata" : "data",
236 lttng_pipe_get_writefd(stream_pipe));
237 if (stream->metadata_flag) {
238 consumer_del_stream_for_metadata(stream);
239 } else {
240 consumer_del_stream_for_data(stream);
241 }
242 }
243 error:
244 return ret;
245 }
246
247 static
248 int get_stream_shm_path(char *stream_shm_path, const char *shm_path, int cpu)
249 {
250 char cpu_nr[INT_MAX_STR_LEN]; /* int max len */
251 int ret;
252
253 strncpy(stream_shm_path, shm_path, PATH_MAX);
254 stream_shm_path[PATH_MAX - 1] = '\0';
255 ret = snprintf(cpu_nr, INT_MAX_STR_LEN, "%i", cpu);
256 if (ret < 0) {
257 PERROR("snprintf");
258 goto end;
259 }
260 strncat(stream_shm_path, cpu_nr,
261 PATH_MAX - strlen(stream_shm_path) - 1);
262 ret = 0;
263 end:
264 return ret;
265 }
266
267 /*
268 * Create streams for the given channel using liblttng-ust-ctl.
269 *
270 * Return 0 on success else a negative value.
271 */
272 static int create_ust_streams(struct lttng_consumer_channel *channel,
273 struct lttng_consumer_local_data *ctx)
274 {
275 int ret, cpu = 0;
276 struct ustctl_consumer_stream *ustream;
277 struct lttng_consumer_stream *stream;
278
279 assert(channel);
280 assert(ctx);
281
282 /*
283 * While a stream is available from ustctl. When NULL is returned, we've
284 * reached the end of the possible stream for the channel.
285 */
286 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
287 int wait_fd;
288 int ust_metadata_pipe[2];
289
290 health_code_update();
291
292 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
293 ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
294 if (ret < 0) {
295 ERR("Create ust metadata poll pipe");
296 goto error;
297 }
298 wait_fd = ust_metadata_pipe[0];
299 } else {
300 wait_fd = ustctl_stream_get_wait_fd(ustream);
301 }
302
303 /* Allocate consumer stream object. */
304 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
305 if (!stream) {
306 goto error_alloc;
307 }
308 stream->ustream = ustream;
309 /*
310 * Store it so we can save multiple function calls afterwards since
311 * this value is used heavily in the stream threads. This is UST
312 * specific so this is why it's done after allocation.
313 */
314 stream->wait_fd = wait_fd;
315
316 /*
317 * Increment channel refcount since the channel reference has now been
318 * assigned in the allocation process above.
319 */
320 if (stream->chan->monitor) {
321 uatomic_inc(&stream->chan->refcount);
322 }
323
324 /*
325 * Order is important this is why a list is used. On error, the caller
326 * should clean this list.
327 */
328 cds_list_add_tail(&stream->send_node, &channel->streams.head);
329
330 ret = ustctl_get_max_subbuf_size(stream->ustream,
331 &stream->max_sb_size);
332 if (ret < 0) {
333 ERR("ustctl_get_max_subbuf_size failed for stream %s",
334 stream->name);
335 goto error;
336 }
337
338 /* Do actions once stream has been received. */
339 if (ctx->on_recv_stream) {
340 ret = ctx->on_recv_stream(stream);
341 if (ret < 0) {
342 goto error;
343 }
344 }
345
346 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
347 stream->name, stream->key, stream->relayd_stream_id);
348
349 /* Set next CPU stream. */
350 channel->streams.count = ++cpu;
351
352 /* Keep stream reference when creating metadata. */
353 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
354 channel->metadata_stream = stream;
355 if (channel->monitor) {
356 /* Set metadata poll pipe if we created one */
357 memcpy(stream->ust_metadata_poll_pipe,
358 ust_metadata_pipe,
359 sizeof(ust_metadata_pipe));
360 }
361 }
362 }
363
364 return 0;
365
366 error:
367 error_alloc:
368 return ret;
369 }
370
371 /*
372 * create_posix_shm is never called concurrently within a process.
373 */
374 static
375 int create_posix_shm(void)
376 {
377 char tmp_name[NAME_MAX];
378 int shmfd, ret;
379
380 ret = snprintf(tmp_name, NAME_MAX, "/ust-shm-consumer-%d", getpid());
381 if (ret < 0) {
382 PERROR("snprintf");
383 return -1;
384 }
385 /*
386 * Allocate shm, and immediately unlink its shm oject, keeping
387 * only the file descriptor as a reference to the object.
388 * We specifically do _not_ use the / at the beginning of the
389 * pathname so that some OS implementations can keep it local to
390 * the process (POSIX leaves this implementation-defined).
391 */
392 shmfd = shm_open(tmp_name, O_CREAT | O_EXCL | O_RDWR, 0700);
393 if (shmfd < 0) {
394 PERROR("shm_open");
395 goto error_shm_open;
396 }
397 ret = shm_unlink(tmp_name);
398 if (ret < 0 && errno != ENOENT) {
399 PERROR("shm_unlink");
400 goto error_shm_release;
401 }
402 return shmfd;
403
404 error_shm_release:
405 ret = close(shmfd);
406 if (ret) {
407 PERROR("close");
408 }
409 error_shm_open:
410 return -1;
411 }
412
413 static int open_ust_stream_fd(struct lttng_consumer_channel *channel,
414 struct ustctl_consumer_channel_attr *attr,
415 int cpu)
416 {
417 char shm_path[PATH_MAX];
418 int ret;
419
420 if (!channel->shm_path[0]) {
421 return create_posix_shm();
422 }
423 ret = get_stream_shm_path(shm_path, channel->shm_path, cpu);
424 if (ret) {
425 goto error_shm_path;
426 }
427 return run_as_open(shm_path,
428 O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR,
429 channel->uid, channel->gid);
430
431 error_shm_path:
432 return -1;
433 }
434
435 /*
436 * Create an UST channel with the given attributes and send it to the session
437 * daemon using the ust ctl API.
438 *
439 * Return 0 on success or else a negative value.
440 */
441 static int create_ust_channel(struct lttng_consumer_channel *channel,
442 struct ustctl_consumer_channel_attr *attr,
443 struct ustctl_consumer_channel **ust_chanp)
444 {
445 int ret, nr_stream_fds, i, j;
446 int *stream_fds;
447 struct ustctl_consumer_channel *ust_channel;
448
449 assert(channel);
450 assert(attr);
451 assert(ust_chanp);
452
453 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
454 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
455 "switch_timer_interval: %u, read_timer_interval: %u, "
456 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
457 attr->num_subbuf, attr->switch_timer_interval,
458 attr->read_timer_interval, attr->output, attr->type);
459
460 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA)
461 nr_stream_fds = 1;
462 else
463 nr_stream_fds = ustctl_get_nr_stream_per_channel();
464 stream_fds = zmalloc(nr_stream_fds * sizeof(*stream_fds));
465 if (!stream_fds) {
466 ret = -1;
467 goto error_alloc;
468 }
469 for (i = 0; i < nr_stream_fds; i++) {
470 stream_fds[i] = open_ust_stream_fd(channel, attr, i);
471 if (stream_fds[i] < 0) {
472 ret = -1;
473 goto error_open;
474 }
475 }
476 ust_channel = ustctl_create_channel(attr, stream_fds, nr_stream_fds);
477 if (!ust_channel) {
478 ret = -1;
479 goto error_create;
480 }
481 channel->nr_stream_fds = nr_stream_fds;
482 channel->stream_fds = stream_fds;
483 *ust_chanp = ust_channel;
484
485 return 0;
486
487 error_create:
488 error_open:
489 for (j = i - 1; j >= 0; j--) {
490 int closeret;
491
492 closeret = close(stream_fds[j]);
493 if (closeret) {
494 PERROR("close");
495 }
496 if (channel->shm_path[0]) {
497 char shm_path[PATH_MAX];
498
499 closeret = get_stream_shm_path(shm_path,
500 channel->shm_path, j);
501 if (closeret) {
502 ERR("Cannot get stream shm path");
503 }
504 closeret = run_as_unlink(shm_path,
505 channel->uid, channel->gid);
506 if (closeret) {
507 PERROR("unlink %s", shm_path);
508 }
509 }
510 }
511 /* Try to rmdir all directories under shm_path root. */
512 if (channel->root_shm_path[0]) {
513 (void) run_as_rmdir_recursive(channel->root_shm_path,
514 channel->uid, channel->gid);
515 }
516 free(stream_fds);
517 error_alloc:
518 return ret;
519 }
520
521 /*
522 * Send a single given stream to the session daemon using the sock.
523 *
524 * Return 0 on success else a negative value.
525 */
526 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
527 {
528 int ret;
529
530 assert(stream);
531 assert(sock >= 0);
532
533 DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
534
535 /* Send stream to session daemon. */
536 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
537 if (ret < 0) {
538 goto error;
539 }
540
541 error:
542 return ret;
543 }
544
545 /*
546 * Send channel to sessiond.
547 *
548 * Return 0 on success or else a negative value.
549 */
550 static int send_sessiond_channel(int sock,
551 struct lttng_consumer_channel *channel,
552 struct lttng_consumer_local_data *ctx, int *relayd_error)
553 {
554 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
555 struct lttng_consumer_stream *stream;
556 uint64_t net_seq_idx = -1ULL;
557
558 assert(channel);
559 assert(ctx);
560 assert(sock >= 0);
561
562 DBG("UST consumer sending channel %s to sessiond", channel->name);
563
564 if (channel->relayd_id != (uint64_t) -1ULL) {
565 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
566
567 health_code_update();
568
569 /* Try to send the stream to the relayd if one is available. */
570 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
571 if (ret < 0) {
572 /*
573 * Flag that the relayd was the problem here probably due to a
574 * communicaton error on the socket.
575 */
576 if (relayd_error) {
577 *relayd_error = 1;
578 }
579 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
580 }
581 if (net_seq_idx == -1ULL) {
582 net_seq_idx = stream->net_seq_idx;
583 }
584 }
585 }
586
587 /* Inform sessiond that we are about to send channel and streams. */
588 ret = consumer_send_status_msg(sock, ret_code);
589 if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
590 /*
591 * Either the session daemon is not responding or the relayd died so we
592 * stop now.
593 */
594 goto error;
595 }
596
597 /* Send channel to sessiond. */
598 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
599 if (ret < 0) {
600 goto error;
601 }
602
603 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
604 if (ret < 0) {
605 goto error;
606 }
607
608 /* The channel was sent successfully to the sessiond at this point. */
609 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
610
611 health_code_update();
612
613 /* Send stream to session daemon. */
614 ret = send_sessiond_stream(sock, stream);
615 if (ret < 0) {
616 goto error;
617 }
618 }
619
620 /* Tell sessiond there is no more stream. */
621 ret = ustctl_send_stream_to_sessiond(sock, NULL);
622 if (ret < 0) {
623 goto error;
624 }
625
626 DBG("UST consumer NULL stream sent to sessiond");
627
628 return 0;
629
630 error:
631 if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
632 ret = -1;
633 }
634 return ret;
635 }
636
637 /*
638 * Creates a channel and streams and add the channel it to the channel internal
639 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
640 * received.
641 *
642 * Return 0 on success or else, a negative value is returned and the channel
643 * MUST be destroyed by consumer_del_channel().
644 */
645 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
646 struct lttng_consumer_channel *channel,
647 struct ustctl_consumer_channel_attr *attr)
648 {
649 int ret;
650
651 assert(ctx);
652 assert(channel);
653 assert(attr);
654
655 /*
656 * This value is still used by the kernel consumer since for the kernel,
657 * the stream ownership is not IN the consumer so we need to have the
658 * number of left stream that needs to be initialized so we can know when
659 * to delete the channel (see consumer.c).
660 *
661 * As for the user space tracer now, the consumer creates and sends the
662 * stream to the session daemon which only sends them to the application
663 * once every stream of a channel is received making this value useless
664 * because we they will be added to the poll thread before the application
665 * receives them. This ensures that a stream can not hang up during
666 * initilization of a channel.
667 */
668 channel->nb_init_stream_left = 0;
669
670 /* The reply msg status is handled in the following call. */
671 ret = create_ust_channel(channel, attr, &channel->uchan);
672 if (ret < 0) {
673 goto end;
674 }
675
676 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
677
678 /*
679 * For the snapshots (no monitor), we create the metadata streams
680 * on demand, not during the channel creation.
681 */
682 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
683 ret = 0;
684 goto end;
685 }
686
687 /* Open all streams for this channel. */
688 ret = create_ust_streams(channel, ctx);
689 if (ret < 0) {
690 goto end;
691 }
692
693 end:
694 return ret;
695 }
696
697 /*
698 * Send all stream of a channel to the right thread handling it.
699 *
700 * On error, return a negative value else 0 on success.
701 */
702 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
703 struct lttng_consumer_local_data *ctx)
704 {
705 int ret = 0;
706 struct lttng_consumer_stream *stream, *stmp;
707
708 assert(channel);
709 assert(ctx);
710
711 /* Send streams to the corresponding thread. */
712 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
713 send_node) {
714
715 health_code_update();
716
717 /* Sending the stream to the thread. */
718 ret = send_stream_to_thread(stream, ctx);
719 if (ret < 0) {
720 /*
721 * If we are unable to send the stream to the thread, there is
722 * a big problem so just stop everything.
723 */
724 /* Remove node from the channel stream list. */
725 cds_list_del(&stream->send_node);
726 goto error;
727 }
728
729 /* Remove node from the channel stream list. */
730 cds_list_del(&stream->send_node);
731
732 }
733
734 error:
735 return ret;
736 }
737
738 /*
739 * Flush channel's streams using the given key to retrieve the channel.
740 *
741 * Return 0 on success else an LTTng error code.
742 */
743 static int flush_channel(uint64_t chan_key)
744 {
745 int ret = 0;
746 struct lttng_consumer_channel *channel;
747 struct lttng_consumer_stream *stream;
748 struct lttng_ht *ht;
749 struct lttng_ht_iter iter;
750
751 DBG("UST consumer flush channel key %" PRIu64, chan_key);
752
753 rcu_read_lock();
754 channel = consumer_find_channel(chan_key);
755 if (!channel) {
756 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
757 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
758 goto error;
759 }
760
761 ht = consumer_data.stream_per_chan_id_ht;
762
763 /* For each stream of the channel id, flush it. */
764 cds_lfht_for_each_entry_duplicate(ht->ht,
765 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
766 &channel->key, &iter.iter, stream, node_channel_id.node) {
767
768 health_code_update();
769
770 pthread_mutex_lock(&stream->lock);
771 if (!stream->quiescent) {
772 ustctl_flush_buffer(stream->ustream, 0);
773 stream->quiescent = true;
774 }
775 pthread_mutex_unlock(&stream->lock);
776 }
777 error:
778 rcu_read_unlock();
779 return ret;
780 }
781
782 /*
783 * Clear quiescent state from channel's streams using the given key to
784 * retrieve the channel.
785 *
786 * Return 0 on success else an LTTng error code.
787 */
788 static int clear_quiescent_channel(uint64_t chan_key)
789 {
790 int ret = 0;
791 struct lttng_consumer_channel *channel;
792 struct lttng_consumer_stream *stream;
793 struct lttng_ht *ht;
794 struct lttng_ht_iter iter;
795
796 DBG("UST consumer clear quiescent channel key %" PRIu64, chan_key);
797
798 rcu_read_lock();
799 channel = consumer_find_channel(chan_key);
800 if (!channel) {
801 ERR("UST consumer clear quiescent channel %" PRIu64 " not found", chan_key);
802 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
803 goto error;
804 }
805
806 ht = consumer_data.stream_per_chan_id_ht;
807
808 /* For each stream of the channel id, clear quiescent state. */
809 cds_lfht_for_each_entry_duplicate(ht->ht,
810 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
811 &channel->key, &iter.iter, stream, node_channel_id.node) {
812
813 health_code_update();
814
815 pthread_mutex_lock(&stream->lock);
816 stream->quiescent = false;
817 pthread_mutex_unlock(&stream->lock);
818 }
819 error:
820 rcu_read_unlock();
821 return ret;
822 }
823
824 /*
825 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
826 * RCU read side lock MUST be acquired before calling this function.
827 *
828 * Return 0 on success else an LTTng error code.
829 */
830 static int close_metadata(uint64_t chan_key)
831 {
832 int ret = 0;
833 struct lttng_consumer_channel *channel;
834 unsigned int channel_monitor;
835
836 DBG("UST consumer close metadata key %" PRIu64, chan_key);
837
838 channel = consumer_find_channel(chan_key);
839 if (!channel) {
840 /*
841 * This is possible if the metadata thread has issue a delete because
842 * the endpoint point of the stream hung up. There is no way the
843 * session daemon can know about it thus use a DBG instead of an actual
844 * error.
845 */
846 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
847 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
848 goto error;
849 }
850
851 pthread_mutex_lock(&consumer_data.lock);
852 pthread_mutex_lock(&channel->lock);
853 channel_monitor = channel->monitor;
854 if (cds_lfht_is_node_deleted(&channel->node.node)) {
855 goto error_unlock;
856 }
857
858 lttng_ustconsumer_close_metadata(channel);
859 pthread_mutex_unlock(&channel->lock);
860 pthread_mutex_unlock(&consumer_data.lock);
861
862 /*
863 * The ownership of a metadata channel depends on the type of
864 * session to which it belongs. In effect, the monitor flag is checked
865 * to determine if this metadata channel is in "snapshot" mode or not.
866 *
867 * In the non-snapshot case, the metadata channel is created along with
868 * a single stream which will remain present until the metadata channel
869 * is destroyed (on the destruction of its session). In this case, the
870 * metadata stream in "monitored" by the metadata poll thread and holds
871 * the ownership of its channel.
872 *
873 * Closing the metadata will cause the metadata stream's "metadata poll
874 * pipe" to be closed. Closing this pipe will wake-up the metadata poll
875 * thread which will teardown the metadata stream which, in return,
876 * deletes the metadata channel.
877 *
878 * In the snapshot case, the metadata stream is created and destroyed
879 * on every snapshot record. Since the channel doesn't have an owner
880 * other than the session daemon, it is safe to destroy it immediately
881 * on reception of the CLOSE_METADATA command.
882 */
883 if (!channel_monitor) {
884 /*
885 * The channel and consumer_data locks must be
886 * released before this call since consumer_del_channel
887 * re-acquires the channel and consumer_data locks to teardown
888 * the channel and queue its reclamation by the "call_rcu"
889 * worker thread.
890 */
891 consumer_del_channel(channel);
892 }
893
894 return ret;
895 error_unlock:
896 pthread_mutex_unlock(&channel->lock);
897 pthread_mutex_unlock(&consumer_data.lock);
898 error:
899 return ret;
900 }
901
902 /*
903 * RCU read side lock MUST be acquired before calling this function.
904 *
905 * Return 0 on success else an LTTng error code.
906 */
907 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
908 {
909 int ret;
910 struct lttng_consumer_channel *metadata;
911
912 DBG("UST consumer setup metadata key %" PRIu64, key);
913
914 metadata = consumer_find_channel(key);
915 if (!metadata) {
916 ERR("UST consumer push metadata %" PRIu64 " not found", key);
917 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
918 goto end;
919 }
920
921 /*
922 * In no monitor mode, the metadata channel has no stream(s) so skip the
923 * ownership transfer to the metadata thread.
924 */
925 if (!metadata->monitor) {
926 DBG("Metadata channel in no monitor");
927 ret = 0;
928 goto end;
929 }
930
931 /*
932 * Send metadata stream to relayd if one available. Availability is
933 * known if the stream is still in the list of the channel.
934 */
935 if (cds_list_empty(&metadata->streams.head)) {
936 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
937 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
938 goto error_no_stream;
939 }
940
941 /* Send metadata stream to relayd if needed. */
942 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
943 ret = consumer_send_relayd_stream(metadata->metadata_stream,
944 metadata->pathname);
945 if (ret < 0) {
946 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
947 goto error;
948 }
949 ret = consumer_send_relayd_streams_sent(
950 metadata->metadata_stream->net_seq_idx);
951 if (ret < 0) {
952 ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
953 goto error;
954 }
955 }
956
957 ret = send_streams_to_thread(metadata, ctx);
958 if (ret < 0) {
959 /*
960 * If we are unable to send the stream to the thread, there is
961 * a big problem so just stop everything.
962 */
963 ret = LTTCOMM_CONSUMERD_FATAL;
964 goto error;
965 }
966 /* List MUST be empty after or else it could be reused. */
967 assert(cds_list_empty(&metadata->streams.head));
968
969 ret = 0;
970 goto end;
971
972 error:
973 /*
974 * Delete metadata channel on error. At this point, the metadata stream can
975 * NOT be monitored by the metadata thread thus having the guarantee that
976 * the stream is still in the local stream list of the channel. This call
977 * will make sure to clean that list.
978 */
979 consumer_stream_destroy(metadata->metadata_stream, NULL);
980 cds_list_del(&metadata->metadata_stream->send_node);
981 metadata->metadata_stream = NULL;
982 error_no_stream:
983 end:
984 return ret;
985 }
986
987 /*
988 * Snapshot the whole metadata.
989 *
990 * Returns 0 on success, < 0 on error
991 */
992 static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
993 struct lttng_consumer_local_data *ctx)
994 {
995 int ret = 0;
996 struct lttng_consumer_channel *metadata_channel;
997 struct lttng_consumer_stream *metadata_stream;
998
999 assert(path);
1000 assert(ctx);
1001
1002 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
1003 key, path);
1004
1005 rcu_read_lock();
1006
1007 metadata_channel = consumer_find_channel(key);
1008 if (!metadata_channel) {
1009 ERR("UST snapshot metadata channel not found for key %" PRIu64,
1010 key);
1011 ret = -1;
1012 goto error;
1013 }
1014 assert(!metadata_channel->monitor);
1015
1016 health_code_update();
1017
1018 /*
1019 * Ask the sessiond if we have new metadata waiting and update the
1020 * consumer metadata cache.
1021 */
1022 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
1023 if (ret < 0) {
1024 goto error;
1025 }
1026
1027 health_code_update();
1028
1029 /*
1030 * The metadata stream is NOT created in no monitor mode when the channel
1031 * is created on a sessiond ask channel command.
1032 */
1033 ret = create_ust_streams(metadata_channel, ctx);
1034 if (ret < 0) {
1035 goto error;
1036 }
1037
1038 metadata_stream = metadata_channel->metadata_stream;
1039 assert(metadata_stream);
1040
1041 if (relayd_id != (uint64_t) -1ULL) {
1042 metadata_stream->net_seq_idx = relayd_id;
1043 ret = consumer_send_relayd_stream(metadata_stream, path);
1044 if (ret < 0) {
1045 goto error_stream;
1046 }
1047 } else {
1048 ret = utils_create_stream_file(path, metadata_stream->name,
1049 metadata_stream->chan->tracefile_size,
1050 metadata_stream->tracefile_count_current,
1051 metadata_stream->uid, metadata_stream->gid, NULL);
1052 if (ret < 0) {
1053 goto error_stream;
1054 }
1055 metadata_stream->out_fd = ret;
1056 metadata_stream->tracefile_size_current = 0;
1057 }
1058
1059 do {
1060 health_code_update();
1061
1062 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
1063 if (ret < 0) {
1064 goto error_stream;
1065 }
1066 } while (ret > 0);
1067
1068 error_stream:
1069 /*
1070 * Clean up the stream completly because the next snapshot will use a new
1071 * metadata stream.
1072 */
1073 consumer_stream_destroy(metadata_stream, NULL);
1074 cds_list_del(&metadata_stream->send_node);
1075 metadata_channel->metadata_stream = NULL;
1076
1077 error:
1078 rcu_read_unlock();
1079 return ret;
1080 }
1081
1082 /*
1083 * Take a snapshot of all the stream of a channel.
1084 *
1085 * Returns 0 on success, < 0 on error
1086 */
1087 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
1088 uint64_t nb_packets_per_stream, struct lttng_consumer_local_data *ctx)
1089 {
1090 int ret;
1091 unsigned use_relayd = 0;
1092 unsigned long consumed_pos, produced_pos;
1093 struct lttng_consumer_channel *channel;
1094 struct lttng_consumer_stream *stream;
1095
1096 assert(path);
1097 assert(ctx);
1098
1099 rcu_read_lock();
1100
1101 if (relayd_id != (uint64_t) -1ULL) {
1102 use_relayd = 1;
1103 }
1104
1105 channel = consumer_find_channel(key);
1106 if (!channel) {
1107 ERR("UST snapshot channel not found for key %" PRIu64, key);
1108 ret = -1;
1109 goto error;
1110 }
1111 assert(!channel->monitor);
1112 DBG("UST consumer snapshot channel %" PRIu64, key);
1113
1114 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
1115 health_code_update();
1116
1117 /* Lock stream because we are about to change its state. */
1118 pthread_mutex_lock(&stream->lock);
1119 stream->net_seq_idx = relayd_id;
1120
1121 if (use_relayd) {
1122 ret = consumer_send_relayd_stream(stream, path);
1123 if (ret < 0) {
1124 goto error_unlock;
1125 }
1126 } else {
1127 ret = utils_create_stream_file(path, stream->name,
1128 stream->chan->tracefile_size,
1129 stream->tracefile_count_current,
1130 stream->uid, stream->gid, NULL);
1131 if (ret < 0) {
1132 goto error_unlock;
1133 }
1134 stream->out_fd = ret;
1135 stream->tracefile_size_current = 0;
1136
1137 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
1138 stream->name, stream->key);
1139 }
1140
1141 /*
1142 * If tracing is active, we want to perform a "full" buffer flush.
1143 * Else, if quiescent, it has already been done by the prior stop.
1144 */
1145 if (!stream->quiescent) {
1146 ustctl_flush_buffer(stream->ustream, 0);
1147 }
1148
1149 ret = lttng_ustconsumer_take_snapshot(stream);
1150 if (ret < 0) {
1151 ERR("Taking UST snapshot");
1152 goto error_unlock;
1153 }
1154
1155 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
1156 if (ret < 0) {
1157 ERR("Produced UST snapshot position");
1158 goto error_unlock;
1159 }
1160
1161 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
1162 if (ret < 0) {
1163 ERR("Consumerd UST snapshot position");
1164 goto error_unlock;
1165 }
1166
1167 /*
1168 * The original value is sent back if max stream size is larger than
1169 * the possible size of the snapshot. Also, we assume that the session
1170 * daemon should never send a maximum stream size that is lower than
1171 * subbuffer size.
1172 */
1173 consumed_pos = consumer_get_consume_start_pos(consumed_pos,
1174 produced_pos, nb_packets_per_stream,
1175 stream->max_sb_size);
1176
1177 while (consumed_pos < produced_pos) {
1178 ssize_t read_len;
1179 unsigned long len, padded_len;
1180
1181 health_code_update();
1182
1183 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
1184
1185 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
1186 if (ret < 0) {
1187 if (ret != -EAGAIN) {
1188 PERROR("ustctl_get_subbuf snapshot");
1189 goto error_close_stream;
1190 }
1191 DBG("UST consumer get subbuf failed. Skipping it.");
1192 consumed_pos += stream->max_sb_size;
1193 stream->chan->lost_packets++;
1194 continue;
1195 }
1196
1197 ret = ustctl_get_subbuf_size(stream->ustream, &len);
1198 if (ret < 0) {
1199 ERR("Snapshot ustctl_get_subbuf_size");
1200 goto error_put_subbuf;
1201 }
1202
1203 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
1204 if (ret < 0) {
1205 ERR("Snapshot ustctl_get_padded_subbuf_size");
1206 goto error_put_subbuf;
1207 }
1208
1209 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
1210 padded_len - len, NULL);
1211 if (use_relayd) {
1212 if (read_len != len) {
1213 ret = -EPERM;
1214 goto error_put_subbuf;
1215 }
1216 } else {
1217 if (read_len != padded_len) {
1218 ret = -EPERM;
1219 goto error_put_subbuf;
1220 }
1221 }
1222
1223 ret = ustctl_put_subbuf(stream->ustream);
1224 if (ret < 0) {
1225 ERR("Snapshot ustctl_put_subbuf");
1226 goto error_close_stream;
1227 }
1228 consumed_pos += stream->max_sb_size;
1229 }
1230
1231 /* Simply close the stream so we can use it on the next snapshot. */
1232 consumer_stream_close(stream);
1233 pthread_mutex_unlock(&stream->lock);
1234 }
1235
1236 rcu_read_unlock();
1237 return 0;
1238
1239 error_put_subbuf:
1240 if (ustctl_put_subbuf(stream->ustream) < 0) {
1241 ERR("Snapshot ustctl_put_subbuf");
1242 }
1243 error_close_stream:
1244 consumer_stream_close(stream);
1245 error_unlock:
1246 pthread_mutex_unlock(&stream->lock);
1247 error:
1248 rcu_read_unlock();
1249 return ret;
1250 }
1251
1252 /*
1253 * Receive the metadata updates from the sessiond. Supports receiving
1254 * overlapping metadata, but is needs to always belong to a contiguous
1255 * range starting from 0.
1256 * Be careful about the locks held when calling this function: it needs
1257 * the metadata cache flush to concurrently progress in order to
1258 * complete.
1259 */
1260 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1261 uint64_t len, uint64_t version,
1262 struct lttng_consumer_channel *channel, int timer, int wait)
1263 {
1264 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1265 char *metadata_str;
1266
1267 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
1268
1269 metadata_str = zmalloc(len * sizeof(char));
1270 if (!metadata_str) {
1271 PERROR("zmalloc metadata string");
1272 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1273 goto end;
1274 }
1275
1276 health_code_update();
1277
1278 /* Receive metadata string. */
1279 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1280 if (ret < 0) {
1281 /* Session daemon is dead so return gracefully. */
1282 ret_code = ret;
1283 goto end_free;
1284 }
1285
1286 health_code_update();
1287
1288 pthread_mutex_lock(&channel->metadata_cache->lock);
1289 ret = consumer_metadata_cache_write(channel, offset, len, version,
1290 metadata_str);
1291 if (ret < 0) {
1292 /* Unable to handle metadata. Notify session daemon. */
1293 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1294 /*
1295 * Skip metadata flush on write error since the offset and len might
1296 * not have been updated which could create an infinite loop below when
1297 * waiting for the metadata cache to be flushed.
1298 */
1299 pthread_mutex_unlock(&channel->metadata_cache->lock);
1300 goto end_free;
1301 }
1302 pthread_mutex_unlock(&channel->metadata_cache->lock);
1303
1304 if (!wait) {
1305 goto end_free;
1306 }
1307 while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
1308 DBG("Waiting for metadata to be flushed");
1309
1310 health_code_update();
1311
1312 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1313 }
1314
1315 end_free:
1316 free(metadata_str);
1317 end:
1318 return ret_code;
1319 }
1320
1321 /*
1322 * Receive command from session daemon and process it.
1323 *
1324 * Return 1 on success else a negative value or 0.
1325 */
1326 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1327 int sock, struct pollfd *consumer_sockpoll)
1328 {
1329 ssize_t ret;
1330 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1331 struct lttcomm_consumer_msg msg;
1332 struct lttng_consumer_channel *channel = NULL;
1333
1334 health_code_update();
1335
1336 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1337 if (ret != sizeof(msg)) {
1338 DBG("Consumer received unexpected message size %zd (expects %zu)",
1339 ret, sizeof(msg));
1340 /*
1341 * The ret value might 0 meaning an orderly shutdown but this is ok
1342 * since the caller handles this.
1343 */
1344 if (ret > 0) {
1345 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1346 ret = -1;
1347 }
1348 return ret;
1349 }
1350
1351 health_code_update();
1352
1353 /* deprecated */
1354 assert(msg.cmd_type != LTTNG_CONSUMER_STOP);
1355
1356 health_code_update();
1357
1358 /* relayd needs RCU read-side lock */
1359 rcu_read_lock();
1360
1361 switch (msg.cmd_type) {
1362 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1363 {
1364 /* Session daemon status message are handled in the following call. */
1365 consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1366 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1367 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
1368 msg.u.relayd_sock.relayd_session_id);
1369 goto end_nosignal;
1370 }
1371 case LTTNG_CONSUMER_DESTROY_RELAYD:
1372 {
1373 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1374 struct consumer_relayd_sock_pair *relayd;
1375
1376 DBG("UST consumer destroying relayd %" PRIu64, index);
1377
1378 /* Get relayd reference if exists. */
1379 relayd = consumer_find_relayd(index);
1380 if (relayd == NULL) {
1381 DBG("Unable to find relayd %" PRIu64, index);
1382 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
1383 }
1384
1385 /*
1386 * Each relayd socket pair has a refcount of stream attached to it
1387 * which tells if the relayd is still active or not depending on the
1388 * refcount value.
1389 *
1390 * This will set the destroy flag of the relayd object and destroy it
1391 * if the refcount reaches zero when called.
1392 *
1393 * The destroy can happen either here or when a stream fd hangs up.
1394 */
1395 if (relayd) {
1396 consumer_flag_relayd_for_destroy(relayd);
1397 }
1398
1399 goto end_msg_sessiond;
1400 }
1401 case LTTNG_CONSUMER_UPDATE_STREAM:
1402 {
1403 rcu_read_unlock();
1404 return -ENOSYS;
1405 }
1406 case LTTNG_CONSUMER_DATA_PENDING:
1407 {
1408 int ret, is_data_pending;
1409 uint64_t id = msg.u.data_pending.session_id;
1410
1411 DBG("UST consumer data pending command for id %" PRIu64, id);
1412
1413 is_data_pending = consumer_data_pending(id);
1414
1415 /* Send back returned value to session daemon */
1416 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1417 sizeof(is_data_pending));
1418 if (ret < 0) {
1419 DBG("Error when sending the data pending ret code: %d", ret);
1420 goto error_fatal;
1421 }
1422
1423 /*
1424 * No need to send back a status message since the data pending
1425 * returned value is the response.
1426 */
1427 break;
1428 }
1429 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1430 {
1431 int ret;
1432 struct ustctl_consumer_channel_attr attr;
1433
1434 /* Create a plain object and reserve a channel key. */
1435 channel = allocate_channel(msg.u.ask_channel.session_id,
1436 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1437 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1438 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1439 (enum lttng_event_output) msg.u.ask_channel.output,
1440 msg.u.ask_channel.tracefile_size,
1441 msg.u.ask_channel.tracefile_count,
1442 msg.u.ask_channel.session_id_per_pid,
1443 msg.u.ask_channel.monitor,
1444 msg.u.ask_channel.live_timer_interval,
1445 msg.u.ask_channel.root_shm_path,
1446 msg.u.ask_channel.shm_path);
1447 if (!channel) {
1448 goto end_channel_error;
1449 }
1450
1451 /*
1452 * Assign UST application UID to the channel. This value is ignored for
1453 * per PID buffers. This is specific to UST thus setting this after the
1454 * allocation.
1455 */
1456 channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
1457
1458 /* Build channel attributes from received message. */
1459 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1460 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1461 attr.overwrite = msg.u.ask_channel.overwrite;
1462 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1463 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1464 attr.chan_id = msg.u.ask_channel.chan_id;
1465 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1466 attr.blocking_timeout= msg.u.ask_channel.blocking_timeout;
1467
1468 /* Match channel buffer type to the UST abi. */
1469 switch (msg.u.ask_channel.output) {
1470 case LTTNG_EVENT_MMAP:
1471 default:
1472 attr.output = LTTNG_UST_MMAP;
1473 break;
1474 }
1475
1476 /* Translate and save channel type. */
1477 switch (msg.u.ask_channel.type) {
1478 case LTTNG_UST_CHAN_PER_CPU:
1479 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1480 attr.type = LTTNG_UST_CHAN_PER_CPU;
1481 /*
1482 * Set refcount to 1 for owner. Below, we will
1483 * pass ownership to the
1484 * consumer_thread_channel_poll() thread.
1485 */
1486 channel->refcount = 1;
1487 break;
1488 case LTTNG_UST_CHAN_METADATA:
1489 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1490 attr.type = LTTNG_UST_CHAN_METADATA;
1491 break;
1492 default:
1493 assert(0);
1494 goto error_fatal;
1495 };
1496
1497 health_code_update();
1498
1499 ret = ask_channel(ctx, sock, channel, &attr);
1500 if (ret < 0) {
1501 goto end_channel_error;
1502 }
1503
1504 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1505 ret = consumer_metadata_cache_allocate(channel);
1506 if (ret < 0) {
1507 ERR("Allocating metadata cache");
1508 goto end_channel_error;
1509 }
1510 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1511 attr.switch_timer_interval = 0;
1512 } else {
1513 int monitor_start_ret;
1514
1515 consumer_timer_live_start(channel,
1516 msg.u.ask_channel.live_timer_interval);
1517 monitor_start_ret = consumer_timer_monitor_start(
1518 channel,
1519 msg.u.ask_channel.monitor_timer_interval);
1520 if (monitor_start_ret < 0) {
1521 ERR("Starting channel monitoring timer failed");
1522 goto end_channel_error;
1523 }
1524 }
1525
1526 health_code_update();
1527
1528 /*
1529 * Add the channel to the internal state AFTER all streams were created
1530 * and successfully sent to session daemon. This way, all streams must
1531 * be ready before this channel is visible to the threads.
1532 * If add_channel succeeds, ownership of the channel is
1533 * passed to consumer_thread_channel_poll().
1534 */
1535 ret = add_channel(channel, ctx);
1536 if (ret < 0) {
1537 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1538 if (channel->switch_timer_enabled == 1) {
1539 consumer_timer_switch_stop(channel);
1540 }
1541 consumer_metadata_cache_destroy(channel);
1542 }
1543 if (channel->live_timer_enabled == 1) {
1544 consumer_timer_live_stop(channel);
1545 }
1546 if (channel->monitor_timer_enabled == 1) {
1547 consumer_timer_monitor_stop(channel);
1548 }
1549 goto end_channel_error;
1550 }
1551
1552 health_code_update();
1553
1554 /*
1555 * Channel and streams are now created. Inform the session daemon that
1556 * everything went well and should wait to receive the channel and
1557 * streams with ustctl API.
1558 */
1559 ret = consumer_send_status_channel(sock, channel);
1560 if (ret < 0) {
1561 /*
1562 * There is probably a problem on the socket.
1563 */
1564 goto error_fatal;
1565 }
1566
1567 break;
1568 }
1569 case LTTNG_CONSUMER_GET_CHANNEL:
1570 {
1571 int ret, relayd_err = 0;
1572 uint64_t key = msg.u.get_channel.key;
1573 struct lttng_consumer_channel *channel;
1574
1575 channel = consumer_find_channel(key);
1576 if (!channel) {
1577 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1578 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1579 goto end_msg_sessiond;
1580 }
1581
1582 health_code_update();
1583
1584 /* Send everything to sessiond. */
1585 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1586 if (ret < 0) {
1587 if (relayd_err) {
1588 /*
1589 * We were unable to send to the relayd the stream so avoid
1590 * sending back a fatal error to the thread since this is OK
1591 * and the consumer can continue its work. The above call
1592 * has sent the error status message to the sessiond.
1593 */
1594 goto end_nosignal;
1595 }
1596 /*
1597 * The communicaton was broken hence there is a bad state between
1598 * the consumer and sessiond so stop everything.
1599 */
1600 goto error_fatal;
1601 }
1602
1603 health_code_update();
1604
1605 /*
1606 * In no monitor mode, the streams ownership is kept inside the channel
1607 * so don't send them to the data thread.
1608 */
1609 if (!channel->monitor) {
1610 goto end_msg_sessiond;
1611 }
1612
1613 ret = send_streams_to_thread(channel, ctx);
1614 if (ret < 0) {
1615 /*
1616 * If we are unable to send the stream to the thread, there is
1617 * a big problem so just stop everything.
1618 */
1619 goto error_fatal;
1620 }
1621 /* List MUST be empty after or else it could be reused. */
1622 assert(cds_list_empty(&channel->streams.head));
1623 goto end_msg_sessiond;
1624 }
1625 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1626 {
1627 uint64_t key = msg.u.destroy_channel.key;
1628
1629 /*
1630 * Only called if streams have not been sent to stream
1631 * manager thread. However, channel has been sent to
1632 * channel manager thread.
1633 */
1634 notify_thread_del_channel(ctx, key);
1635 goto end_msg_sessiond;
1636 }
1637 case LTTNG_CONSUMER_CLOSE_METADATA:
1638 {
1639 int ret;
1640
1641 ret = close_metadata(msg.u.close_metadata.key);
1642 if (ret != 0) {
1643 ret_code = ret;
1644 }
1645
1646 goto end_msg_sessiond;
1647 }
1648 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1649 {
1650 int ret;
1651
1652 ret = flush_channel(msg.u.flush_channel.key);
1653 if (ret != 0) {
1654 ret_code = ret;
1655 }
1656
1657 goto end_msg_sessiond;
1658 }
1659 case LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL:
1660 {
1661 int ret;
1662
1663 ret = clear_quiescent_channel(
1664 msg.u.clear_quiescent_channel.key);
1665 if (ret != 0) {
1666 ret_code = ret;
1667 }
1668
1669 goto end_msg_sessiond;
1670 }
1671 case LTTNG_CONSUMER_PUSH_METADATA:
1672 {
1673 int ret;
1674 uint64_t len = msg.u.push_metadata.len;
1675 uint64_t key = msg.u.push_metadata.key;
1676 uint64_t offset = msg.u.push_metadata.target_offset;
1677 uint64_t version = msg.u.push_metadata.version;
1678 struct lttng_consumer_channel *channel;
1679
1680 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1681 len);
1682
1683 channel = consumer_find_channel(key);
1684 if (!channel) {
1685 /*
1686 * This is possible if the metadata creation on the consumer side
1687 * is in flight vis-a-vis a concurrent push metadata from the
1688 * session daemon. Simply return that the channel failed and the
1689 * session daemon will handle that message correctly considering
1690 * that this race is acceptable thus the DBG() statement here.
1691 */
1692 DBG("UST consumer push metadata %" PRIu64 " not found", key);
1693 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1694 goto end_msg_sessiond;
1695 }
1696
1697 health_code_update();
1698
1699 if (!len) {
1700 /*
1701 * There is nothing to receive. We have simply
1702 * checked whether the channel can be found.
1703 */
1704 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1705 goto end_msg_sessiond;
1706 }
1707
1708 /* Tell session daemon we are ready to receive the metadata. */
1709 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
1710 if (ret < 0) {
1711 /* Somehow, the session daemon is not responding anymore. */
1712 goto error_fatal;
1713 }
1714
1715 health_code_update();
1716
1717 /* Wait for more data. */
1718 health_poll_entry();
1719 ret = lttng_consumer_poll_socket(consumer_sockpoll);
1720 health_poll_exit();
1721 if (ret) {
1722 goto error_fatal;
1723 }
1724
1725 health_code_update();
1726
1727 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1728 len, version, channel, 0, 1);
1729 if (ret < 0) {
1730 /* error receiving from sessiond */
1731 goto error_fatal;
1732 } else {
1733 ret_code = ret;
1734 goto end_msg_sessiond;
1735 }
1736 }
1737 case LTTNG_CONSUMER_SETUP_METADATA:
1738 {
1739 int ret;
1740
1741 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1742 if (ret) {
1743 ret_code = ret;
1744 }
1745 goto end_msg_sessiond;
1746 }
1747 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1748 {
1749 if (msg.u.snapshot_channel.metadata) {
1750 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1751 msg.u.snapshot_channel.pathname,
1752 msg.u.snapshot_channel.relayd_id,
1753 ctx);
1754 if (ret < 0) {
1755 ERR("Snapshot metadata failed");
1756 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1757 }
1758 } else {
1759 ret = snapshot_channel(msg.u.snapshot_channel.key,
1760 msg.u.snapshot_channel.pathname,
1761 msg.u.snapshot_channel.relayd_id,
1762 msg.u.snapshot_channel.nb_packets_per_stream,
1763 ctx);
1764 if (ret < 0) {
1765 ERR("Snapshot channel failed");
1766 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1767 }
1768 }
1769
1770 health_code_update();
1771 ret = consumer_send_status_msg(sock, ret_code);
1772 if (ret < 0) {
1773 /* Somehow, the session daemon is not responding anymore. */
1774 goto end_nosignal;
1775 }
1776 health_code_update();
1777 break;
1778 }
1779 case LTTNG_CONSUMER_DISCARDED_EVENTS:
1780 {
1781 int ret = 0;
1782 uint64_t discarded_events;
1783 struct lttng_ht_iter iter;
1784 struct lttng_ht *ht;
1785 struct lttng_consumer_stream *stream;
1786 uint64_t id = msg.u.discarded_events.session_id;
1787 uint64_t key = msg.u.discarded_events.channel_key;
1788
1789 DBG("UST consumer discarded events command for session id %"
1790 PRIu64, id);
1791 rcu_read_lock();
1792 pthread_mutex_lock(&consumer_data.lock);
1793
1794 ht = consumer_data.stream_list_ht;
1795
1796 /*
1797 * We only need a reference to the channel, but they are not
1798 * directly indexed, so we just use the first matching stream
1799 * to extract the information we need, we default to 0 if not
1800 * found (no events are dropped if the channel is not yet in
1801 * use).
1802 */
1803 discarded_events = 0;
1804 cds_lfht_for_each_entry_duplicate(ht->ht,
1805 ht->hash_fct(&id, lttng_ht_seed),
1806 ht->match_fct, &id,
1807 &iter.iter, stream, node_session_id.node) {
1808 if (stream->chan->key == key) {
1809 discarded_events = stream->chan->discarded_events;
1810 break;
1811 }
1812 }
1813 pthread_mutex_unlock(&consumer_data.lock);
1814 rcu_read_unlock();
1815
1816 DBG("UST consumer discarded events command for session id %"
1817 PRIu64 ", channel key %" PRIu64, id, key);
1818
1819 health_code_update();
1820
1821 /* Send back returned value to session daemon */
1822 ret = lttcomm_send_unix_sock(sock, &discarded_events, sizeof(discarded_events));
1823 if (ret < 0) {
1824 PERROR("send discarded events");
1825 goto error_fatal;
1826 }
1827
1828 break;
1829 }
1830 case LTTNG_CONSUMER_LOST_PACKETS:
1831 {
1832 int ret;
1833 uint64_t lost_packets;
1834 struct lttng_ht_iter iter;
1835 struct lttng_ht *ht;
1836 struct lttng_consumer_stream *stream;
1837 uint64_t id = msg.u.lost_packets.session_id;
1838 uint64_t key = msg.u.lost_packets.channel_key;
1839
1840 DBG("UST consumer lost packets command for session id %"
1841 PRIu64, id);
1842 rcu_read_lock();
1843 pthread_mutex_lock(&consumer_data.lock);
1844
1845 ht = consumer_data.stream_list_ht;
1846
1847 /*
1848 * We only need a reference to the channel, but they are not
1849 * directly indexed, so we just use the first matching stream
1850 * to extract the information we need, we default to 0 if not
1851 * found (no packets lost if the channel is not yet in use).
1852 */
1853 lost_packets = 0;
1854 cds_lfht_for_each_entry_duplicate(ht->ht,
1855 ht->hash_fct(&id, lttng_ht_seed),
1856 ht->match_fct, &id,
1857 &iter.iter, stream, node_session_id.node) {
1858 if (stream->chan->key == key) {
1859 lost_packets = stream->chan->lost_packets;
1860 break;
1861 }
1862 }
1863 pthread_mutex_unlock(&consumer_data.lock);
1864 rcu_read_unlock();
1865
1866 DBG("UST consumer lost packets command for session id %"
1867 PRIu64 ", channel key %" PRIu64, id, key);
1868
1869 health_code_update();
1870
1871 /* Send back returned value to session daemon */
1872 ret = lttcomm_send_unix_sock(sock, &lost_packets,
1873 sizeof(lost_packets));
1874 if (ret < 0) {
1875 PERROR("send lost packets");
1876 goto error_fatal;
1877 }
1878
1879 break;
1880 }
1881 case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE:
1882 {
1883 int channel_monitor_pipe;
1884
1885 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1886 /* Successfully received the command's type. */
1887 ret = consumer_send_status_msg(sock, ret_code);
1888 if (ret < 0) {
1889 goto error_fatal;
1890 }
1891
1892 ret = lttcomm_recv_fds_unix_sock(sock, &channel_monitor_pipe,
1893 1);
1894 if (ret != sizeof(channel_monitor_pipe)) {
1895 ERR("Failed to receive channel monitor pipe");
1896 goto error_fatal;
1897 }
1898
1899 DBG("Received channel monitor pipe (%d)", channel_monitor_pipe);
1900 ret = consumer_timer_thread_set_channel_monitor_pipe(
1901 channel_monitor_pipe);
1902 if (!ret) {
1903 int flags;
1904
1905 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1906 /* Set the pipe as non-blocking. */
1907 ret = fcntl(channel_monitor_pipe, F_GETFL, 0);
1908 if (ret == -1) {
1909 PERROR("fcntl get flags of the channel monitoring pipe");
1910 goto error_fatal;
1911 }
1912 flags = ret;
1913
1914 ret = fcntl(channel_monitor_pipe, F_SETFL,
1915 flags | O_NONBLOCK);
1916 if (ret == -1) {
1917 PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
1918 goto error_fatal;
1919 }
1920 DBG("Channel monitor pipe set as non-blocking");
1921 } else {
1922 ret_code = LTTCOMM_CONSUMERD_ALREADY_SET;
1923 }
1924 goto end_msg_sessiond;
1925 }
1926 case LTTNG_CONSUMER_CLEAR_CHANNEL:
1927 {
1928 struct lttng_consumer_channel *channel;
1929 uint64_t key = msg.u.clear_channel.key;
1930
1931 channel = consumer_find_channel(key);
1932 if (!channel) {
1933 DBG("Channel %" PRIu64 " not found", key);
1934 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1935 } else {
1936 ret = lttng_consumer_clear_channel(channel);
1937 if (ret) {
1938 ERR("Clear channel failed key %" PRIu64, key);
1939 ret_code = ret;
1940 }
1941
1942 health_code_update();
1943 }
1944 ret = consumer_send_status_msg(sock, ret_code);
1945 if (ret < 0) {
1946 /* Somehow, the session daemon is not responding anymore. */
1947 goto end_nosignal;
1948 }
1949 break;
1950 }
1951 default:
1952 break;
1953 }
1954
1955 end_nosignal:
1956 rcu_read_unlock();
1957
1958 health_code_update();
1959
1960 /*
1961 * Return 1 to indicate success since the 0 value can be a socket
1962 * shutdown during the recv() or send() call.
1963 */
1964 return 1;
1965
1966 end_msg_sessiond:
1967 /*
1968 * The returned value here is not useful since either way we'll return 1 to
1969 * the caller because the session daemon socket management is done
1970 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1971 */
1972 ret = consumer_send_status_msg(sock, ret_code);
1973 if (ret < 0) {
1974 goto error_fatal;
1975 }
1976 rcu_read_unlock();
1977
1978 health_code_update();
1979
1980 return 1;
1981 end_channel_error:
1982 if (channel) {
1983 /*
1984 * Free channel here since no one has a reference to it. We don't
1985 * free after that because a stream can store this pointer.
1986 */
1987 destroy_channel(channel);
1988 }
1989 /* We have to send a status channel message indicating an error. */
1990 ret = consumer_send_status_channel(sock, NULL);
1991 if (ret < 0) {
1992 /* Stop everything if session daemon can not be notified. */
1993 goto error_fatal;
1994 }
1995 rcu_read_unlock();
1996
1997 health_code_update();
1998
1999 return 1;
2000 error_fatal:
2001 rcu_read_unlock();
2002 /* This will issue a consumer stop. */
2003 return -1;
2004 }
2005
2006 /*
2007 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
2008 * compiled out, we isolate it in this library.
2009 */
2010 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
2011 unsigned long *off)
2012 {
2013 assert(stream);
2014 assert(stream->ustream);
2015
2016 return ustctl_get_mmap_read_offset(stream->ustream, off);
2017 }
2018
2019 /*
2020 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
2021 * compiled out, we isolate it in this library.
2022 */
2023 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
2024 {
2025 assert(stream);
2026 assert(stream->ustream);
2027
2028 return ustctl_get_mmap_base(stream->ustream);
2029 }
2030
2031 /*
2032 * Take a snapshot for a specific stream.
2033 *
2034 * Returns 0 on success, < 0 on error
2035 */
2036 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
2037 {
2038 assert(stream);
2039 assert(stream->ustream);
2040
2041 return ustctl_snapshot(stream->ustream);
2042 }
2043
2044 /*
2045 * Sample consumed and produced positions for a specific stream.
2046 *
2047 * Returns 0 on success, < 0 on error.
2048 */
2049 int lttng_ustconsumer_sample_snapshot_positions(
2050 struct lttng_consumer_stream *stream)
2051 {
2052 assert(stream);
2053 assert(stream->ustream);
2054
2055 return ustctl_snapshot_sample_positions(stream->ustream);
2056 }
2057
2058 /*
2059 * Get the produced position
2060 *
2061 * Returns 0 on success, < 0 on error
2062 */
2063 int lttng_ustconsumer_get_produced_snapshot(
2064 struct lttng_consumer_stream *stream, unsigned long *pos)
2065 {
2066 assert(stream);
2067 assert(stream->ustream);
2068 assert(pos);
2069
2070 return ustctl_snapshot_get_produced(stream->ustream, pos);
2071 }
2072
2073 /*
2074 * Get the consumed position
2075 *
2076 * Returns 0 on success, < 0 on error
2077 */
2078 int lttng_ustconsumer_get_consumed_snapshot(
2079 struct lttng_consumer_stream *stream, unsigned long *pos)
2080 {
2081 assert(stream);
2082 assert(stream->ustream);
2083 assert(pos);
2084
2085 return ustctl_snapshot_get_consumed(stream->ustream, pos);
2086 }
2087
2088 void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
2089 int producer)
2090 {
2091 assert(stream);
2092 assert(stream->ustream);
2093
2094 ustctl_flush_buffer(stream->ustream, producer);
2095 }
2096
2097 void lttng_ustconsumer_clear_buffer(struct lttng_consumer_stream *stream)
2098 {
2099 assert(stream);
2100 assert(stream->ustream);
2101
2102 ustctl_clear_buffer(stream->ustream);
2103 }
2104
2105 int lttng_ustconsumer_get_current_timestamp(
2106 struct lttng_consumer_stream *stream, uint64_t *ts)
2107 {
2108 assert(stream);
2109 assert(stream->ustream);
2110 assert(ts);
2111
2112 return ustctl_get_current_timestamp(stream->ustream, ts);
2113 }
2114
2115 int lttng_ustconsumer_get_sequence_number(
2116 struct lttng_consumer_stream *stream, uint64_t *seq)
2117 {
2118 assert(stream);
2119 assert(stream->ustream);
2120 assert(seq);
2121
2122 return ustctl_get_sequence_number(stream->ustream, seq);
2123 }
2124
2125 /*
2126 * Called when the stream signals the consumer that it has hung up.
2127 */
2128 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
2129 {
2130 assert(stream);
2131 assert(stream->ustream);
2132
2133 pthread_mutex_lock(&stream->lock);
2134 if (!stream->quiescent) {
2135 ustctl_flush_buffer(stream->ustream, 0);
2136 stream->quiescent = true;
2137 }
2138 pthread_mutex_unlock(&stream->lock);
2139 stream->hangup_flush_done = 1;
2140 }
2141
2142 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
2143 {
2144 int i;
2145
2146 assert(chan);
2147 assert(chan->uchan);
2148
2149 if (chan->switch_timer_enabled == 1) {
2150 consumer_timer_switch_stop(chan);
2151 }
2152 for (i = 0; i < chan->nr_stream_fds; i++) {
2153 int ret;
2154
2155 ret = close(chan->stream_fds[i]);
2156 if (ret) {
2157 PERROR("close");
2158 }
2159 if (chan->shm_path[0]) {
2160 char shm_path[PATH_MAX];
2161
2162 ret = get_stream_shm_path(shm_path, chan->shm_path, i);
2163 if (ret) {
2164 ERR("Cannot get stream shm path");
2165 }
2166 ret = run_as_unlink(shm_path, chan->uid, chan->gid);
2167 if (ret) {
2168 PERROR("unlink %s", shm_path);
2169 }
2170 }
2171 }
2172 }
2173
2174 void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
2175 {
2176 assert(chan);
2177 assert(chan->uchan);
2178
2179 consumer_metadata_cache_destroy(chan);
2180 ustctl_destroy_channel(chan->uchan);
2181 /* Try to rmdir all directories under shm_path root. */
2182 if (chan->root_shm_path[0]) {
2183 (void) run_as_rmdir_recursive(chan->root_shm_path,
2184 chan->uid, chan->gid);
2185 }
2186 free(chan->stream_fds);
2187 }
2188
2189 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
2190 {
2191 assert(stream);
2192 assert(stream->ustream);
2193
2194 if (stream->chan->switch_timer_enabled == 1) {
2195 consumer_timer_switch_stop(stream->chan);
2196 }
2197 ustctl_destroy_stream(stream->ustream);
2198 }
2199
2200 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
2201 {
2202 assert(stream);
2203 assert(stream->ustream);
2204
2205 return ustctl_stream_get_wakeup_fd(stream->ustream);
2206 }
2207
2208 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
2209 {
2210 assert(stream);
2211 assert(stream->ustream);
2212
2213 return ustctl_stream_close_wakeup_fd(stream->ustream);
2214 }
2215
2216 /*
2217 * Populate index values of a UST stream. Values are set in big endian order.
2218 *
2219 * Return 0 on success or else a negative value.
2220 */
2221 static int get_index_values(struct ctf_packet_index *index,
2222 struct ustctl_consumer_stream *ustream)
2223 {
2224 int ret;
2225
2226 ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
2227 if (ret < 0) {
2228 PERROR("ustctl_get_timestamp_begin");
2229 goto error;
2230 }
2231 index->timestamp_begin = htobe64(index->timestamp_begin);
2232
2233 ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
2234 if (ret < 0) {
2235 PERROR("ustctl_get_timestamp_end");
2236 goto error;
2237 }
2238 index->timestamp_end = htobe64(index->timestamp_end);
2239
2240 ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
2241 if (ret < 0) {
2242 PERROR("ustctl_get_events_discarded");
2243 goto error;
2244 }
2245 index->events_discarded = htobe64(index->events_discarded);
2246
2247 ret = ustctl_get_content_size(ustream, &index->content_size);
2248 if (ret < 0) {
2249 PERROR("ustctl_get_content_size");
2250 goto error;
2251 }
2252 index->content_size = htobe64(index->content_size);
2253
2254 ret = ustctl_get_packet_size(ustream, &index->packet_size);
2255 if (ret < 0) {
2256 PERROR("ustctl_get_packet_size");
2257 goto error;
2258 }
2259 index->packet_size = htobe64(index->packet_size);
2260
2261 ret = ustctl_get_stream_id(ustream, &index->stream_id);
2262 if (ret < 0) {
2263 PERROR("ustctl_get_stream_id");
2264 goto error;
2265 }
2266 index->stream_id = htobe64(index->stream_id);
2267
2268 ret = ustctl_get_instance_id(ustream, &index->stream_instance_id);
2269 if (ret < 0) {
2270 PERROR("ustctl_get_instance_id");
2271 goto error;
2272 }
2273 index->stream_instance_id = htobe64(index->stream_instance_id);
2274
2275 ret = ustctl_get_sequence_number(ustream, &index->packet_seq_num);
2276 if (ret < 0) {
2277 PERROR("ustctl_get_sequence_number");
2278 goto error;
2279 }
2280 index->packet_seq_num = htobe64(index->packet_seq_num);
2281
2282 error:
2283 return ret;
2284 }
2285
2286 static
2287 void metadata_stream_reset_cache(struct lttng_consumer_stream *stream,
2288 struct consumer_metadata_cache *cache)
2289 {
2290 DBG("Metadata stream update to version %" PRIu64,
2291 cache->version);
2292 stream->ust_metadata_pushed = 0;
2293 stream->metadata_version = cache->version;
2294 stream->reset_metadata_flag = 1;
2295 }
2296
2297 /*
2298 * Check if the version of the metadata stream and metadata cache match.
2299 * If the cache got updated, reset the metadata stream.
2300 * The stream lock and metadata cache lock MUST be held.
2301 * Return 0 on success, a negative value on error.
2302 */
2303 static
2304 int metadata_stream_check_version(struct lttng_consumer_stream *stream)
2305 {
2306 int ret = 0;
2307 struct consumer_metadata_cache *cache = stream->chan->metadata_cache;
2308
2309 if (cache->version == stream->metadata_version) {
2310 goto end;
2311 }
2312 metadata_stream_reset_cache(stream, cache);
2313
2314 end:
2315 return ret;
2316 }
2317
2318 /*
2319 * Write up to one packet from the metadata cache to the channel.
2320 *
2321 * Returns the number of bytes pushed in the cache, or a negative value
2322 * on error.
2323 */
2324 static
2325 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
2326 {
2327 ssize_t write_len;
2328 int ret;
2329
2330 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
2331 ret = metadata_stream_check_version(stream);
2332 if (ret < 0) {
2333 goto end;
2334 }
2335 if (stream->chan->metadata_cache->max_offset
2336 == stream->ust_metadata_pushed) {
2337 ret = 0;
2338 goto end;
2339 }
2340
2341 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
2342 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
2343 stream->chan->metadata_cache->max_offset
2344 - stream->ust_metadata_pushed);
2345 assert(write_len != 0);
2346 if (write_len < 0) {
2347 ERR("Writing one metadata packet");
2348 ret = -1;
2349 goto end;
2350 }
2351 stream->ust_metadata_pushed += write_len;
2352
2353 assert(stream->chan->metadata_cache->max_offset >=
2354 stream->ust_metadata_pushed);
2355 ret = write_len;
2356
2357 end:
2358 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
2359 return ret;
2360 }
2361
2362
2363 /*
2364 * Sync metadata meaning request them to the session daemon and snapshot to the
2365 * metadata thread can consumer them.
2366 *
2367 * Metadata stream lock is held here, but we need to release it when
2368 * interacting with sessiond, else we cause a deadlock with live
2369 * awaiting on metadata to be pushed out.
2370 *
2371 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
2372 * is empty or a negative value on error.
2373 */
2374 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
2375 struct lttng_consumer_stream *metadata)
2376 {
2377 int ret;
2378 int retry = 0;
2379
2380 assert(ctx);
2381 assert(metadata);
2382
2383 pthread_mutex_unlock(&metadata->lock);
2384 /*
2385 * Request metadata from the sessiond, but don't wait for the flush
2386 * because we locked the metadata thread.
2387 */
2388 ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
2389 pthread_mutex_lock(&metadata->lock);
2390 if (ret < 0) {
2391 goto end;
2392 }
2393
2394 ret = commit_one_metadata_packet(metadata);
2395 if (ret <= 0) {
2396 goto end;
2397 } else if (ret > 0) {
2398 retry = 1;
2399 }
2400
2401 ustctl_flush_buffer(metadata->ustream, 1);
2402 ret = ustctl_snapshot(metadata->ustream);
2403 if (ret < 0) {
2404 if (errno != EAGAIN) {
2405 ERR("Sync metadata, taking UST snapshot");
2406 goto end;
2407 }
2408 DBG("No new metadata when syncing them.");
2409 /* No new metadata, exit. */
2410 ret = ENODATA;
2411 goto end;
2412 }
2413
2414 /*
2415 * After this flush, we still need to extract metadata.
2416 */
2417 if (retry) {
2418 ret = EAGAIN;
2419 }
2420
2421 end:
2422 return ret;
2423 }
2424
2425 /*
2426 * Return 0 on success else a negative value.
2427 */
2428 static int notify_if_more_data(struct lttng_consumer_stream *stream,
2429 struct lttng_consumer_local_data *ctx)
2430 {
2431 int ret;
2432 struct ustctl_consumer_stream *ustream;
2433
2434 assert(stream);
2435 assert(ctx);
2436
2437 ustream = stream->ustream;
2438
2439 /*
2440 * First, we are going to check if there is a new subbuffer available
2441 * before reading the stream wait_fd.
2442 */
2443 /* Get the next subbuffer */
2444 ret = ustctl_get_next_subbuf(ustream);
2445 if (ret) {
2446 /* No more data found, flag the stream. */
2447 stream->has_data = 0;
2448 ret = 0;
2449 goto end;
2450 }
2451
2452 ret = ustctl_put_subbuf(ustream);
2453 assert(!ret);
2454
2455 /* This stream still has data. Flag it and wake up the data thread. */
2456 stream->has_data = 1;
2457
2458 if (stream->monitor && !stream->hangup_flush_done && !ctx->has_wakeup) {
2459 ssize_t writelen;
2460
2461 writelen = lttng_pipe_write(ctx->consumer_wakeup_pipe, "!", 1);
2462 if (writelen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2463 ret = writelen;
2464 goto end;
2465 }
2466
2467 /* The wake up pipe has been notified. */
2468 ctx->has_wakeup = 1;
2469 }
2470 ret = 0;
2471
2472 end:
2473 return ret;
2474 }
2475
2476 static
2477 int update_stream_stats(struct lttng_consumer_stream *stream)
2478 {
2479 int ret;
2480 uint64_t seq, discarded;
2481
2482 ret = ustctl_get_sequence_number(stream->ustream, &seq);
2483 if (ret < 0) {
2484 PERROR("ustctl_get_sequence_number");
2485 goto end;
2486 }
2487 /*
2488 * Start the sequence when we extract the first packet in case we don't
2489 * start at 0 (for example if a consumer is not connected to the
2490 * session immediately after the beginning).
2491 */
2492 if (stream->last_sequence_number == -1ULL) {
2493 stream->last_sequence_number = seq;
2494 } else if (seq > stream->last_sequence_number) {
2495 stream->chan->lost_packets += seq -
2496 stream->last_sequence_number - 1;
2497 } else {
2498 /* seq <= last_sequence_number */
2499 ERR("Sequence number inconsistent : prev = %" PRIu64
2500 ", current = %" PRIu64,
2501 stream->last_sequence_number, seq);
2502 ret = -1;
2503 goto end;
2504 }
2505 stream->last_sequence_number = seq;
2506
2507 ret = ustctl_get_events_discarded(stream->ustream, &discarded);
2508 if (ret < 0) {
2509 PERROR("kernctl_get_events_discarded");
2510 goto end;
2511 }
2512 if (discarded < stream->last_discarded_events) {
2513 /*
2514 * Overflow has occurred. We assume only one wrap-around
2515 * has occurred.
2516 */
2517 stream->chan->discarded_events +=
2518 (1ULL << (CAA_BITS_PER_LONG - 1)) -
2519 stream->last_discarded_events + discarded;
2520 } else {
2521 stream->chan->discarded_events += discarded -
2522 stream->last_discarded_events;
2523 }
2524 stream->last_discarded_events = discarded;
2525 ret = 0;
2526
2527 end:
2528 return ret;
2529 }
2530
2531 /*
2532 * Read subbuffer from the given stream.
2533 *
2534 * Stream lock MUST be acquired.
2535 *
2536 * Return 0 on success else a negative value.
2537 */
2538 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
2539 struct lttng_consumer_local_data *ctx)
2540 {
2541 unsigned long len, subbuf_size, padding;
2542 int err, write_index = 1;
2543 long ret = 0;
2544 struct ustctl_consumer_stream *ustream;
2545 struct ctf_packet_index index;
2546
2547 assert(stream);
2548 assert(stream->ustream);
2549 assert(ctx);
2550
2551 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
2552 stream->name);
2553
2554 /* Ease our life for what's next. */
2555 ustream = stream->ustream;
2556
2557 /*
2558 * We can consume the 1 byte written into the wait_fd by UST. Don't trigger
2559 * error if we cannot read this one byte (read returns 0), or if the error
2560 * is EAGAIN or EWOULDBLOCK.
2561 *
2562 * This is only done when the stream is monitored by a thread, before the
2563 * flush is done after a hangup and if the stream is not flagged with data
2564 * since there might be nothing to consume in the wait fd but still have
2565 * data available flagged by the consumer wake up pipe.
2566 */
2567 if (stream->monitor && !stream->hangup_flush_done && !stream->has_data) {
2568 char dummy;
2569 ssize_t readlen;
2570
2571 readlen = lttng_read(stream->wait_fd, &dummy, 1);
2572 if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2573 ret = readlen;
2574 goto end;
2575 }
2576 }
2577
2578 retry:
2579 /* Get the next subbuffer */
2580 err = ustctl_get_next_subbuf(ustream);
2581 if (err != 0) {
2582 /*
2583 * Populate metadata info if the existing info has
2584 * already been read.
2585 */
2586 if (stream->metadata_flag) {
2587 ret = commit_one_metadata_packet(stream);
2588 if (ret <= 0) {
2589 goto end;
2590 }
2591 ustctl_flush_buffer(stream->ustream, 1);
2592 goto retry;
2593 }
2594
2595 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
2596 /*
2597 * This is a debug message even for single-threaded consumer,
2598 * because poll() have more relaxed criterions than get subbuf,
2599 * so get_subbuf may fail for short race windows where poll()
2600 * would issue wakeups.
2601 */
2602 DBG("Reserving sub buffer failed (everything is normal, "
2603 "it is due to concurrency) [ret: %d]", err);
2604 goto end;
2605 }
2606 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
2607
2608 if (!stream->metadata_flag) {
2609 index.offset = htobe64(stream->out_fd_offset);
2610 ret = get_index_values(&index, ustream);
2611 if (ret < 0) {
2612 err = ustctl_put_subbuf(ustream);
2613 assert(err == 0);
2614 goto end;
2615 }
2616
2617 /* Update the stream's sequence and discarded events count. */
2618 ret = update_stream_stats(stream);
2619 if (ret < 0) {
2620 PERROR("kernctl_get_events_discarded");
2621 err = ustctl_put_subbuf(ustream);
2622 assert(err == 0);
2623 goto end;
2624 }
2625 } else {
2626 write_index = 0;
2627 }
2628
2629 /* Get the full padded subbuffer size */
2630 err = ustctl_get_padded_subbuf_size(ustream, &len);
2631 assert(err == 0);
2632
2633 /* Get subbuffer data size (without padding) */
2634 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
2635 assert(err == 0);
2636
2637 /* Make sure we don't get a subbuffer size bigger than the padded */
2638 assert(len >= subbuf_size);
2639
2640 padding = len - subbuf_size;
2641 /* write the subbuffer to the tracefile */
2642 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
2643 /*
2644 * The mmap operation should write subbuf_size amount of data when network
2645 * streaming or the full padding (len) size when we are _not_ streaming.
2646 */
2647 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
2648 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
2649 /*
2650 * Display the error but continue processing to try to release the
2651 * subbuffer. This is a DBG statement since any unexpected kill or
2652 * signal, the application gets unregistered, relayd gets closed or
2653 * anything that affects the buffer lifetime will trigger this error.
2654 * So, for the sake of the user, don't print this error since it can
2655 * happen and it is OK with the code flow.
2656 */
2657 DBG("Error writing to tracefile "
2658 "(ret: %ld != len: %lu != subbuf_size: %lu)",
2659 ret, len, subbuf_size);
2660 write_index = 0;
2661 }
2662 err = ustctl_put_next_subbuf(ustream);
2663 assert(err == 0);
2664
2665 /*
2666 * This will consumer the byte on the wait_fd if and only if there is not
2667 * next subbuffer to be acquired.
2668 */
2669 if (!stream->metadata_flag) {
2670 ret = notify_if_more_data(stream, ctx);
2671 if (ret < 0) {
2672 goto end;
2673 }
2674 }
2675
2676 /* Write index if needed. */
2677 if (!write_index) {
2678 goto end;
2679 }
2680
2681 if (stream->chan->live_timer_interval && !stream->metadata_flag) {
2682 /*
2683 * In live, block until all the metadata is sent.
2684 */
2685 pthread_mutex_lock(&stream->metadata_timer_lock);
2686 assert(!stream->missed_metadata_flush);
2687 stream->waiting_on_metadata = true;
2688 pthread_mutex_unlock(&stream->metadata_timer_lock);
2689
2690 err = consumer_stream_sync_metadata(ctx, stream->session_id);
2691
2692 pthread_mutex_lock(&stream->metadata_timer_lock);
2693 stream->waiting_on_metadata = false;
2694 if (stream->missed_metadata_flush) {
2695 stream->missed_metadata_flush = false;
2696 pthread_mutex_unlock(&stream->metadata_timer_lock);
2697 (void) consumer_flush_ust_index(stream);
2698 } else {
2699 pthread_mutex_unlock(&stream->metadata_timer_lock);
2700 }
2701
2702 if (err < 0) {
2703 goto end;
2704 }
2705 }
2706
2707 assert(!stream->metadata_flag);
2708 err = consumer_stream_write_index(stream, &index);
2709 if (err < 0) {
2710 goto end;
2711 }
2712
2713 end:
2714 return ret;
2715 }
2716
2717 /*
2718 * Called when a stream is created.
2719 *
2720 * Return 0 on success or else a negative value.
2721 */
2722 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
2723 {
2724 int ret;
2725
2726 assert(stream);
2727
2728 /* Don't create anything if this is set for streaming. */
2729 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
2730 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
2731 stream->chan->tracefile_size, stream->tracefile_count_current,
2732 stream->uid, stream->gid, NULL);
2733 if (ret < 0) {
2734 goto error;
2735 }
2736 stream->out_fd = ret;
2737 stream->tracefile_size_current = 0;
2738
2739 if (!stream->metadata_flag) {
2740 struct lttng_index_file *index_file;
2741
2742 index_file = lttng_index_file_create(stream->chan->pathname,
2743 stream->name, stream->uid, stream->gid,
2744 stream->chan->tracefile_size,
2745 stream->tracefile_count_current,
2746 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
2747 if (!index_file) {
2748 goto error;
2749 }
2750 assert(!stream->index_file);
2751 stream->index_file = index_file;
2752 }
2753 }
2754 ret = 0;
2755
2756 error:
2757 return ret;
2758 }
2759
2760 /*
2761 * Check if data is still being extracted from the buffers for a specific
2762 * stream. Consumer data lock MUST be acquired before calling this function
2763 * and the stream lock.
2764 *
2765 * Return 1 if the traced data are still getting read else 0 meaning that the
2766 * data is available for trace viewer reading.
2767 */
2768 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
2769 {
2770 int ret;
2771
2772 assert(stream);
2773 assert(stream->ustream);
2774
2775 DBG("UST consumer checking data pending");
2776
2777 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
2778 ret = 0;
2779 goto end;
2780 }
2781
2782 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
2783 uint64_t contiguous, pushed;
2784
2785 /* Ease our life a bit. */
2786 contiguous = stream->chan->metadata_cache->max_offset;
2787 pushed = stream->ust_metadata_pushed;
2788
2789 /*
2790 * We can simply check whether all contiguously available data
2791 * has been pushed to the ring buffer, since the push operation
2792 * is performed within get_next_subbuf(), and because both
2793 * get_next_subbuf() and put_next_subbuf() are issued atomically
2794 * thanks to the stream lock within
2795 * lttng_ustconsumer_read_subbuffer(). This basically means that
2796 * whetnever ust_metadata_pushed is incremented, the associated
2797 * metadata has been consumed from the metadata stream.
2798 */
2799 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
2800 contiguous, pushed);
2801 assert(((int64_t) (contiguous - pushed)) >= 0);
2802 if ((contiguous != pushed) ||
2803 (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
2804 ret = 1; /* Data is pending */
2805 goto end;
2806 }
2807 } else {
2808 ret = ustctl_get_next_subbuf(stream->ustream);
2809 if (ret == 0) {
2810 /*
2811 * There is still data so let's put back this
2812 * subbuffer.
2813 */
2814 ret = ustctl_put_subbuf(stream->ustream);
2815 assert(ret == 0);
2816 ret = 1; /* Data is pending */
2817 goto end;
2818 }
2819 }
2820
2821 /* Data is NOT pending so ready to be read. */
2822 ret = 0;
2823
2824 end:
2825 return ret;
2826 }
2827
2828 /*
2829 * Stop a given metadata channel timer if enabled and close the wait fd which
2830 * is the poll pipe of the metadata stream.
2831 *
2832 * This MUST be called with the metadata channel acquired.
2833 */
2834 void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata)
2835 {
2836 int ret;
2837
2838 assert(metadata);
2839 assert(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA);
2840
2841 DBG("Closing metadata channel key %" PRIu64, metadata->key);
2842
2843 if (metadata->switch_timer_enabled == 1) {
2844 consumer_timer_switch_stop(metadata);
2845 }
2846
2847 if (!metadata->metadata_stream) {
2848 goto end;
2849 }
2850
2851 /*
2852 * Closing write side so the thread monitoring the stream wakes up if any
2853 * and clean the metadata stream.
2854 */
2855 if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) {
2856 ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]);
2857 if (ret < 0) {
2858 PERROR("closing metadata pipe write side");
2859 }
2860 metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1;
2861 }
2862
2863 end:
2864 return;
2865 }
2866
2867 /*
2868 * Close every metadata stream wait fd of the metadata hash table. This
2869 * function MUST be used very carefully so not to run into a race between the
2870 * metadata thread handling streams and this function closing their wait fd.
2871 *
2872 * For UST, this is used when the session daemon hangs up. Its the metadata
2873 * producer so calling this is safe because we are assured that no state change
2874 * can occur in the metadata thread for the streams in the hash table.
2875 */
2876 void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht)
2877 {
2878 struct lttng_ht_iter iter;
2879 struct lttng_consumer_stream *stream;
2880
2881 assert(metadata_ht);
2882 assert(metadata_ht->ht);
2883
2884 DBG("UST consumer closing all metadata streams");
2885
2886 rcu_read_lock();
2887 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
2888 node.node) {
2889
2890 health_code_update();
2891
2892 pthread_mutex_lock(&stream->chan->lock);
2893 lttng_ustconsumer_close_metadata(stream->chan);
2894 pthread_mutex_unlock(&stream->chan->lock);
2895
2896 }
2897 rcu_read_unlock();
2898 }
2899
2900 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
2901 {
2902 int ret;
2903
2904 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
2905 if (ret < 0) {
2906 ERR("Unable to close wakeup fd");
2907 }
2908 }
2909
2910 /*
2911 * Please refer to consumer-timer.c before adding any lock within this
2912 * function or any of its callees. Timers have a very strict locking
2913 * semantic with respect to teardown. Failure to respect this semantic
2914 * introduces deadlocks.
2915 *
2916 * DON'T hold the metadata lock when calling this function, else this
2917 * can cause deadlock involving consumer awaiting for metadata to be
2918 * pushed out due to concurrent interaction with the session daemon.
2919 */
2920 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
2921 struct lttng_consumer_channel *channel, int timer, int wait)
2922 {
2923 struct lttcomm_metadata_request_msg request;
2924 struct lttcomm_consumer_msg msg;
2925 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
2926 uint64_t len, key, offset, version;
2927 int ret;
2928
2929 assert(channel);
2930 assert(channel->metadata_cache);
2931
2932 memset(&request, 0, sizeof(request));
2933
2934 /* send the metadata request to sessiond */
2935 switch (consumer_data.type) {
2936 case LTTNG_CONSUMER64_UST:
2937 request.bits_per_long = 64;
2938 break;
2939 case LTTNG_CONSUMER32_UST:
2940 request.bits_per_long = 32;
2941 break;
2942 default:
2943 request.bits_per_long = 0;
2944 break;
2945 }
2946
2947 request.session_id = channel->session_id;
2948 request.session_id_per_pid = channel->session_id_per_pid;
2949 /*
2950 * Request the application UID here so the metadata of that application can
2951 * be sent back. The channel UID corresponds to the user UID of the session
2952 * used for the rights on the stream file(s).
2953 */
2954 request.uid = channel->ust_app_uid;
2955 request.key = channel->key;
2956
2957 DBG("Sending metadata request to sessiond, session id %" PRIu64
2958 ", per-pid %" PRIu64 ", app UID %u and channel key %" PRIu64,
2959 request.session_id, request.session_id_per_pid, request.uid,
2960 request.key);
2961
2962 pthread_mutex_lock(&ctx->metadata_socket_lock);
2963
2964 health_code_update();
2965
2966 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
2967 sizeof(request));
2968 if (ret < 0) {
2969 ERR("Asking metadata to sessiond");
2970 goto end;
2971 }
2972
2973 health_code_update();
2974
2975 /* Receive the metadata from sessiond */
2976 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
2977 sizeof(msg));
2978 if (ret != sizeof(msg)) {
2979 DBG("Consumer received unexpected message size %d (expects %zu)",
2980 ret, sizeof(msg));
2981 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
2982 /*
2983 * The ret value might 0 meaning an orderly shutdown but this is ok
2984 * since the caller handles this.
2985 */
2986 goto end;
2987 }
2988
2989 health_code_update();
2990
2991 if (msg.cmd_type == LTTNG_ERR_UND) {
2992 /* No registry found */
2993 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
2994 ret_code);
2995 ret = 0;
2996 goto end;
2997 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
2998 ERR("Unexpected cmd_type received %d", msg.cmd_type);
2999 ret = -1;
3000 goto end;
3001 }
3002
3003 len = msg.u.push_metadata.len;
3004 key = msg.u.push_metadata.key;
3005 offset = msg.u.push_metadata.target_offset;
3006 version = msg.u.push_metadata.version;
3007
3008 assert(key == channel->key);
3009 if (len == 0) {
3010 DBG("No new metadata to receive for key %" PRIu64, key);
3011 }
3012
3013 health_code_update();
3014
3015 /* Tell session daemon we are ready to receive the metadata. */
3016 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
3017 LTTCOMM_CONSUMERD_SUCCESS);
3018 if (ret < 0 || len == 0) {
3019 /*
3020 * Somehow, the session daemon is not responding anymore or there is
3021 * nothing to receive.
3022 */
3023 goto end;
3024 }
3025
3026 health_code_update();
3027
3028 ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
3029 key, offset, len, version, channel, timer, wait);
3030 if (ret >= 0) {
3031 /*
3032 * Only send the status msg if the sessiond is alive meaning a positive
3033 * ret code.
3034 */
3035 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret);
3036 }
3037 ret = 0;
3038
3039 end:
3040 health_code_update();
3041
3042 pthread_mutex_unlock(&ctx->metadata_socket_lock);
3043 return ret;
3044 }
3045
3046 /*
3047 * Return the ustctl call for the get stream id.
3048 */
3049 int lttng_ustconsumer_get_stream_id(struct lttng_consumer_stream *stream,
3050 uint64_t *stream_id)
3051 {
3052 assert(stream);
3053 assert(stream_id);
3054
3055 return ustctl_get_stream_id(stream->ustream, stream_id);
3056 }
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