b558988dcf1a2ba4fcf6b6cabdff46c7166bbf25
[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 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <assert.h>
21 #include <lttng/ust-ctl.h>
22 #include <poll.h>
23 #include <pthread.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/mman.h>
27 #include <sys/socket.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <inttypes.h>
31 #include <unistd.h>
32 #include <urcu/list.h>
33 #include <signal.h>
34
35 #include <common/common.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/relayd/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/consumer-metadata-cache.h>
40 #include <common/consumer-timer.h>
41
42 #include "ust-consumer.h"
43
44 extern struct lttng_consumer_global_data consumer_data;
45 extern int consumer_poll_timeout;
46 extern volatile int consumer_quit;
47
48 /*
49 * Free channel object and all streams associated with it. This MUST be used
50 * only and only if the channel has _NEVER_ been added to the global channel
51 * hash table.
52 */
53 static void destroy_channel(struct lttng_consumer_channel *channel)
54 {
55 struct lttng_consumer_stream *stream, *stmp;
56
57 assert(channel);
58
59 DBG("UST consumer cleaning stream list");
60
61 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
62 send_node) {
63 cds_list_del(&stream->send_node);
64 ustctl_destroy_stream(stream->ustream);
65 free(stream);
66 }
67
68 /*
69 * If a channel is available meaning that was created before the streams
70 * were, delete it.
71 */
72 if (channel->uchan) {
73 lttng_ustconsumer_del_channel(channel);
74 }
75 free(channel);
76 }
77
78 /*
79 * Add channel to internal consumer state.
80 *
81 * Returns 0 on success or else a negative value.
82 */
83 static int add_channel(struct lttng_consumer_channel *channel,
84 struct lttng_consumer_local_data *ctx)
85 {
86 int ret = 0;
87
88 assert(channel);
89 assert(ctx);
90
91 if (ctx->on_recv_channel != NULL) {
92 ret = ctx->on_recv_channel(channel);
93 if (ret == 0) {
94 ret = consumer_add_channel(channel, ctx);
95 } else if (ret < 0) {
96 /* Most likely an ENOMEM. */
97 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
98 goto error;
99 }
100 } else {
101 ret = consumer_add_channel(channel, ctx);
102 }
103
104 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
105
106 error:
107 return ret;
108 }
109
110 /*
111 * Allocate and return a consumer channel object.
112 */
113 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
114 const char *pathname, const char *name, uid_t uid, gid_t gid,
115 int relayd_id, uint64_t key, enum lttng_event_output output,
116 uint64_t tracefile_size, uint64_t tracefile_count)
117 {
118 assert(pathname);
119 assert(name);
120
121 return consumer_allocate_channel(key, session_id, pathname, name, uid, gid,
122 relayd_id, output, tracefile_size, tracefile_count);
123 }
124
125 /*
126 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
127 * error value if applicable is set in it else it is kept untouched.
128 *
129 * Return NULL on error else the newly allocated stream object.
130 */
131 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
132 struct lttng_consumer_channel *channel,
133 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
134 {
135 int alloc_ret;
136 struct lttng_consumer_stream *stream = NULL;
137
138 assert(channel);
139 assert(ctx);
140
141 stream = consumer_allocate_stream(channel->key,
142 key,
143 LTTNG_CONSUMER_ACTIVE_STREAM,
144 channel->name,
145 channel->uid,
146 channel->gid,
147 channel->relayd_id,
148 channel->session_id,
149 cpu,
150 &alloc_ret,
151 channel->type);
152 if (stream == NULL) {
153 switch (alloc_ret) {
154 case -ENOENT:
155 /*
156 * We could not find the channel. Can happen if cpu hotplug
157 * happens while tearing down.
158 */
159 DBG3("Could not find channel");
160 break;
161 case -ENOMEM:
162 case -EINVAL:
163 default:
164 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
165 break;
166 }
167 goto error;
168 }
169
170 stream->chan = channel;
171
172 error:
173 if (_alloc_ret) {
174 *_alloc_ret = alloc_ret;
175 }
176 return stream;
177 }
178
179 /*
180 * Send the given stream pointer to the corresponding thread.
181 *
182 * Returns 0 on success else a negative value.
183 */
184 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
185 struct lttng_consumer_local_data *ctx)
186 {
187 int ret, stream_pipe;
188
189 /* Get the right pipe where the stream will be sent. */
190 if (stream->metadata_flag) {
191 stream_pipe = ctx->consumer_metadata_pipe[1];
192 } else {
193 stream_pipe = ctx->consumer_data_pipe[1];
194 }
195
196 do {
197 ret = write(stream_pipe, &stream, sizeof(stream));
198 } while (ret < 0 && errno == EINTR);
199 if (ret < 0) {
200 PERROR("Consumer write %s stream to pipe %d",
201 stream->metadata_flag ? "metadata" : "data", stream_pipe);
202 }
203
204 return ret;
205 }
206
207 /*
208 * Search for a relayd object related to the stream. If found, send the stream
209 * to the relayd.
210 *
211 * On success, returns 0 else a negative value.
212 */
213 static int send_stream_to_relayd(struct lttng_consumer_stream *stream)
214 {
215 int ret = 0;
216 struct consumer_relayd_sock_pair *relayd;
217
218 assert(stream);
219
220 relayd = consumer_find_relayd(stream->net_seq_idx);
221 if (relayd != NULL) {
222 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
223 /* Add stream on the relayd */
224 ret = relayd_add_stream(&relayd->control_sock, stream->name,
225 stream->chan->pathname, &stream->relayd_stream_id);
226 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
227 if (ret < 0) {
228 goto error;
229 }
230 } else if (stream->net_seq_idx != (uint64_t) -1ULL) {
231 ERR("Network sequence index %" PRIu64 " unknown. Not adding stream.",
232 stream->net_seq_idx);
233 ret = -1;
234 goto error;
235 }
236
237 error:
238 return ret;
239 }
240
241 /*
242 * Create streams for the given channel using liblttng-ust-ctl.
243 *
244 * Return 0 on success else a negative value.
245 */
246 static int create_ust_streams(struct lttng_consumer_channel *channel,
247 struct lttng_consumer_local_data *ctx)
248 {
249 int ret, cpu = 0;
250 struct ustctl_consumer_stream *ustream;
251 struct lttng_consumer_stream *stream;
252
253 assert(channel);
254 assert(ctx);
255
256 /*
257 * While a stream is available from ustctl. When NULL is returned, we've
258 * reached the end of the possible stream for the channel.
259 */
260 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
261 int wait_fd;
262
263 wait_fd = ustctl_stream_get_wait_fd(ustream);
264
265 /* Allocate consumer stream object. */
266 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
267 if (!stream) {
268 goto error_alloc;
269 }
270 stream->ustream = ustream;
271 /*
272 * Store it so we can save multiple function calls afterwards since
273 * this value is used heavily in the stream threads. This is UST
274 * specific so this is why it's done after allocation.
275 */
276 stream->wait_fd = wait_fd;
277
278 /*
279 * Order is important this is why a list is used. On error, the caller
280 * should clean this list.
281 */
282 cds_list_add_tail(&stream->send_node, &channel->streams.head);
283
284 ret = ustctl_get_max_subbuf_size(stream->ustream,
285 &stream->max_sb_size);
286 if (ret < 0) {
287 ERR("ustctl_get_max_subbuf_size failed for stream %s",
288 stream->name);
289 goto error;
290 }
291
292 /* Do actions once stream has been received. */
293 if (ctx->on_recv_stream) {
294 ret = ctx->on_recv_stream(stream);
295 if (ret < 0) {
296 goto error;
297 }
298 }
299
300 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
301 stream->name, stream->key, stream->relayd_stream_id);
302
303 /* Set next CPU stream. */
304 channel->streams.count = ++cpu;
305
306 /* Keep stream reference when creating metadata. */
307 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
308 channel->metadata_stream = stream;
309 }
310 }
311
312 return 0;
313
314 error:
315 error_alloc:
316 return ret;
317 }
318
319 /*
320 * Create an UST channel with the given attributes and send it to the session
321 * daemon using the ust ctl API.
322 *
323 * Return 0 on success or else a negative value.
324 */
325 static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
326 struct ustctl_consumer_channel **chanp)
327 {
328 int ret;
329 struct ustctl_consumer_channel *channel;
330
331 assert(attr);
332 assert(chanp);
333
334 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
335 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
336 "switch_timer_interval: %u, read_timer_interval: %u, "
337 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
338 attr->num_subbuf, attr->switch_timer_interval,
339 attr->read_timer_interval, attr->output, attr->type);
340
341 channel = ustctl_create_channel(attr);
342 if (!channel) {
343 ret = -1;
344 goto error_create;
345 }
346
347 *chanp = channel;
348
349 return 0;
350
351 error_create:
352 return ret;
353 }
354
355 /*
356 * Send a single given stream to the session daemon using the sock.
357 *
358 * Return 0 on success else a negative value.
359 */
360 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
361 {
362 int ret;
363
364 assert(stream);
365 assert(sock >= 0);
366
367 DBG2("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
368
369 /* Send stream to session daemon. */
370 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
371 if (ret < 0) {
372 goto error;
373 }
374
375 error:
376 return ret;
377 }
378
379 /*
380 * Send channel to sessiond.
381 *
382 * Return 0 on success or else a negative value.
383 */
384 static int send_sessiond_channel(int sock,
385 struct lttng_consumer_channel *channel,
386 struct lttng_consumer_local_data *ctx, int *relayd_error)
387 {
388 int ret;
389 struct lttng_consumer_stream *stream;
390
391 assert(channel);
392 assert(ctx);
393 assert(sock >= 0);
394
395 DBG("UST consumer sending channel %s to sessiond", channel->name);
396
397 /* Send channel to sessiond. */
398 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
399 if (ret < 0) {
400 goto error;
401 }
402
403 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
404 if (ret < 0) {
405 goto error;
406 }
407
408 /* The channel was sent successfully to the sessiond at this point. */
409 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
410 /* Try to send the stream to the relayd if one is available. */
411 ret = send_stream_to_relayd(stream);
412 if (ret < 0) {
413 /*
414 * Flag that the relayd was the problem here probably due to a
415 * communicaton error on the socket.
416 */
417 if (relayd_error) {
418 *relayd_error = 1;
419 }
420 goto error;
421 }
422
423 /* Send stream to session daemon. */
424 ret = send_sessiond_stream(sock, stream);
425 if (ret < 0) {
426 goto error;
427 }
428 }
429
430 /* Tell sessiond there is no more stream. */
431 ret = ustctl_send_stream_to_sessiond(sock, NULL);
432 if (ret < 0) {
433 goto error;
434 }
435
436 DBG("UST consumer NULL stream sent to sessiond");
437
438 return 0;
439
440 error:
441 return ret;
442 }
443
444 /*
445 * Creates a channel and streams and add the channel it to the channel internal
446 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
447 * received.
448 *
449 * Return 0 on success or else, a negative value is returned and the channel
450 * MUST be destroyed by consumer_del_channel().
451 */
452 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
453 struct lttng_consumer_channel *channel,
454 struct ustctl_consumer_channel_attr *attr)
455 {
456 int ret;
457
458 assert(ctx);
459 assert(channel);
460 assert(attr);
461
462 /*
463 * This value is still used by the kernel consumer since for the kernel,
464 * the stream ownership is not IN the consumer so we need to have the
465 * number of left stream that needs to be initialized so we can know when
466 * to delete the channel (see consumer.c).
467 *
468 * As for the user space tracer now, the consumer creates and sends the
469 * stream to the session daemon which only sends them to the application
470 * once every stream of a channel is received making this value useless
471 * because we they will be added to the poll thread before the application
472 * receives them. This ensures that a stream can not hang up during
473 * initilization of a channel.
474 */
475 channel->nb_init_stream_left = 0;
476
477 /* The reply msg status is handled in the following call. */
478 ret = create_ust_channel(attr, &channel->uchan);
479 if (ret < 0) {
480 goto error;
481 }
482
483 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
484
485 if (ret < 0) {
486 goto error;
487 }
488
489 /* Open all streams for this channel. */
490 ret = create_ust_streams(channel, ctx);
491 if (ret < 0) {
492 goto error;
493 }
494
495 error:
496 return ret;
497 }
498
499 /*
500 * Send all stream of a channel to the right thread handling it.
501 *
502 * On error, return a negative value else 0 on success.
503 */
504 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
505 struct lttng_consumer_local_data *ctx)
506 {
507 int ret = 0;
508 struct lttng_consumer_stream *stream, *stmp;
509
510 assert(channel);
511 assert(ctx);
512
513 /* Send streams to the corresponding thread. */
514 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
515 send_node) {
516 /* Sending the stream to the thread. */
517 ret = send_stream_to_thread(stream, ctx);
518 if (ret < 0) {
519 /*
520 * If we are unable to send the stream to the thread, there is
521 * a big problem so just stop everything.
522 */
523 goto error;
524 }
525
526 /* Remove node from the channel stream list. */
527 cds_list_del(&stream->send_node);
528 }
529
530 error:
531 return ret;
532 }
533
534 /*
535 * Write metadata to the given channel using ustctl to convert the string to
536 * the ringbuffer.
537 * Called only from consumer_metadata_cache_write.
538 * The metadata cache lock MUST be acquired to write in the cache.
539 *
540 * Return 0 on success else a negative value.
541 */
542 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel *metadata,
543 const char *metadata_str, uint64_t target_offset, uint64_t len)
544 {
545 int ret;
546
547 assert(metadata);
548 assert(metadata_str);
549
550 DBG("UST consumer writing metadata to channel %s", metadata->name);
551
552 assert(target_offset <= metadata->metadata_cache->max_offset);
553 ret = ustctl_write_metadata_to_channel(metadata->uchan,
554 metadata_str + target_offset, len);
555 if (ret < 0) {
556 ERR("ustctl write metadata fail with ret %d, len %ld", ret, len);
557 goto error;
558 }
559
560 ustctl_flush_buffer(metadata->metadata_stream->ustream, 1);
561
562 error:
563 return ret;
564 }
565
566 /*
567 * Flush channel's streams using the given key to retrieve the channel.
568 *
569 * Return 0 on success else an LTTng error code.
570 */
571 static int flush_channel(uint64_t chan_key)
572 {
573 int ret = 0;
574 struct lttng_consumer_channel *channel;
575 struct lttng_consumer_stream *stream;
576 struct lttng_ht *ht;
577 struct lttng_ht_iter iter;
578
579 DBG("UST consumer flush channel key %lu", chan_key);
580
581 channel = consumer_find_channel(chan_key);
582 if (!channel) {
583 ERR("UST consumer flush channel %lu not found", chan_key);
584 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
585 goto error;
586 }
587
588 ht = consumer_data.stream_per_chan_id_ht;
589
590 /* For each stream of the channel id, flush it. */
591 rcu_read_lock();
592 cds_lfht_for_each_entry_duplicate(ht->ht,
593 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
594 &channel->key, &iter.iter, stream, node_channel_id.node) {
595 ustctl_flush_buffer(stream->ustream, 1);
596 }
597 rcu_read_unlock();
598
599 error:
600 return ret;
601 }
602
603 /*
604 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
605 *
606 * Return 0 on success else an LTTng error code.
607 */
608 static int close_metadata(uint64_t chan_key)
609 {
610 int ret;
611 struct lttng_consumer_channel *channel;
612
613 DBG("UST consumer close metadata key %lu", chan_key);
614
615 channel = consumer_find_channel(chan_key);
616 if (!channel) {
617 ERR("UST consumer close metadata %lu not found", chan_key);
618 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
619 goto error;
620 }
621
622 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
623 if (ret < 0) {
624 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
625 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
626 goto error;
627 }
628 if (channel->switch_timer_enabled == 1) {
629 DBG("Deleting timer on metadata channel");
630 consumer_timer_switch_stop(channel);
631 }
632 consumer_metadata_cache_destroy(channel);
633
634 error:
635 return ret;
636 }
637
638 /*
639 * RCU read side lock MUST be acquired before calling this function.
640 *
641 * Return 0 on success else an LTTng error code.
642 */
643 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
644 {
645 int ret;
646 struct lttng_consumer_channel *metadata;
647
648 DBG("UST consumer setup metadata key %lu", key);
649
650 metadata = consumer_find_channel(key);
651 if (!metadata) {
652 ERR("UST consumer push metadata %" PRIu64 " not found", key);
653 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
654 goto error;
655 }
656
657 /*
658 * Send metadata stream to relayd if one available. Availability is
659 * known if the stream is still in the list of the channel.
660 */
661 if (cds_list_empty(&metadata->streams.head)) {
662 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
663 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
664 goto error;
665 }
666
667 /* Send metadata stream to relayd if needed. */
668 ret = send_stream_to_relayd(metadata->metadata_stream);
669 if (ret < 0) {
670 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
671 goto error;
672 }
673
674 ret = send_streams_to_thread(metadata, ctx);
675 if (ret < 0) {
676 /*
677 * If we are unable to send the stream to the thread, there is
678 * a big problem so just stop everything.
679 */
680 ret = LTTCOMM_CONSUMERD_FATAL;
681 goto error;
682 }
683 /* List MUST be empty after or else it could be reused. */
684 assert(cds_list_empty(&metadata->streams.head));
685
686 ret = 0;
687
688 error:
689 return ret;
690 }
691
692 /*
693 * Receive the metadata updates from the sessiond.
694 */
695 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
696 uint64_t len, struct lttng_consumer_channel *channel)
697 {
698 int ret, ret_code = LTTNG_OK;
699 char *metadata_str;
700
701 DBG("UST consumer push metadata key %lu of len %lu", key, len);
702
703 metadata_str = zmalloc(len * sizeof(char));
704 if (!metadata_str) {
705 PERROR("zmalloc metadata string");
706 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
707 goto end;
708 }
709
710 /* Receive metadata string. */
711 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
712 if (ret < 0) {
713 /* Session daemon is dead so return gracefully. */
714 ret_code = ret;
715 goto end_free;
716 }
717
718 pthread_mutex_lock(&channel->metadata_cache->lock);
719 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
720 if (ret < 0) {
721 /* Unable to handle metadata. Notify session daemon. */
722 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
723 }
724 pthread_mutex_unlock(&channel->metadata_cache->lock);
725
726 while (consumer_metadata_cache_flushed(channel, offset + len)) {
727 DBG("Waiting for metadata to be flushed");
728 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
729 }
730
731 end_free:
732 free(metadata_str);
733 end:
734 return ret_code;
735 }
736
737 /*
738 * Receive command from session daemon and process it.
739 *
740 * Return 1 on success else a negative value or 0.
741 */
742 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
743 int sock, struct pollfd *consumer_sockpoll)
744 {
745 ssize_t ret;
746 enum lttng_error_code ret_code = LTTNG_OK;
747 struct lttcomm_consumer_msg msg;
748 struct lttng_consumer_channel *channel = NULL;
749
750 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
751 if (ret != sizeof(msg)) {
752 DBG("Consumer received unexpected message size %zd (expects %zu)",
753 ret, sizeof(msg));
754 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
755 /*
756 * The ret value might 0 meaning an orderly shutdown but this is ok
757 * since the caller handles this.
758 */
759 return ret;
760 }
761 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
762 /*
763 * Notify the session daemon that the command is completed.
764 *
765 * On transport layer error, the function call will print an error
766 * message so handling the returned code is a bit useless since we
767 * return an error code anyway.
768 */
769 (void) consumer_send_status_msg(sock, ret_code);
770 return -ENOENT;
771 }
772
773 /* relayd needs RCU read-side lock */
774 rcu_read_lock();
775
776 switch (msg.cmd_type) {
777 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
778 {
779 /* Session daemon status message are handled in the following call. */
780 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
781 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
782 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
783 goto end_nosignal;
784 }
785 case LTTNG_CONSUMER_DESTROY_RELAYD:
786 {
787 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
788 struct consumer_relayd_sock_pair *relayd;
789
790 DBG("UST consumer destroying relayd %" PRIu64, index);
791
792 /* Get relayd reference if exists. */
793 relayd = consumer_find_relayd(index);
794 if (relayd == NULL) {
795 DBG("Unable to find relayd %" PRIu64, index);
796 ret_code = LTTNG_ERR_NO_CONSUMER;
797 }
798
799 /*
800 * Each relayd socket pair has a refcount of stream attached to it
801 * which tells if the relayd is still active or not depending on the
802 * refcount value.
803 *
804 * This will set the destroy flag of the relayd object and destroy it
805 * if the refcount reaches zero when called.
806 *
807 * The destroy can happen either here or when a stream fd hangs up.
808 */
809 if (relayd) {
810 consumer_flag_relayd_for_destroy(relayd);
811 }
812
813 goto end_msg_sessiond;
814 }
815 case LTTNG_CONSUMER_UPDATE_STREAM:
816 {
817 rcu_read_unlock();
818 return -ENOSYS;
819 }
820 case LTTNG_CONSUMER_DATA_PENDING:
821 {
822 int ret, is_data_pending;
823 uint64_t id = msg.u.data_pending.session_id;
824
825 DBG("UST consumer data pending command for id %" PRIu64, id);
826
827 is_data_pending = consumer_data_pending(id);
828
829 /* Send back returned value to session daemon */
830 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
831 sizeof(is_data_pending));
832 if (ret < 0) {
833 DBG("Error when sending the data pending ret code: %d", ret);
834 }
835
836 /*
837 * No need to send back a status message since the data pending
838 * returned value is the response.
839 */
840 break;
841 }
842 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
843 {
844 int ret;
845 struct ustctl_consumer_channel_attr attr;
846
847 /* Create a plain object and reserve a channel key. */
848 channel = allocate_channel(msg.u.ask_channel.session_id,
849 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
850 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
851 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
852 (enum lttng_event_output) msg.u.ask_channel.output,
853 msg.u.ask_channel.tracefile_size,
854 msg.u.ask_channel.tracefile_count);
855 if (!channel) {
856 goto end_channel_error;
857 }
858
859 /* Build channel attributes from received message. */
860 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
861 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
862 attr.overwrite = msg.u.ask_channel.overwrite;
863 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
864 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
865 attr.chan_id = msg.u.ask_channel.chan_id;
866 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
867
868 /* Translate the event output type to UST. */
869 switch (channel->output) {
870 case LTTNG_EVENT_SPLICE:
871 /* Splice not supported so fallback on mmap(). */
872 case LTTNG_EVENT_MMAP:
873 default:
874 attr.output = CONSUMER_CHANNEL_MMAP;
875 break;
876 };
877
878 /* Translate and save channel type. */
879 switch (msg.u.ask_channel.type) {
880 case LTTNG_UST_CHAN_PER_CPU:
881 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
882 attr.type = LTTNG_UST_CHAN_PER_CPU;
883 break;
884 case LTTNG_UST_CHAN_METADATA:
885 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
886 attr.type = LTTNG_UST_CHAN_METADATA;
887 break;
888 default:
889 assert(0);
890 goto error_fatal;
891 };
892
893 ret = ask_channel(ctx, sock, channel, &attr);
894 if (ret < 0) {
895 goto end_channel_error;
896 }
897
898 /*
899 * Add the channel to the internal state AFTER all streams were created
900 * and successfully sent to session daemon. This way, all streams must
901 * be ready before this channel is visible to the threads.
902 */
903 ret = add_channel(channel, ctx);
904 if (ret < 0) {
905 goto end_channel_error;
906 }
907
908
909 /*
910 * Channel and streams are now created. Inform the session daemon that
911 * everything went well and should wait to receive the channel and
912 * streams with ustctl API.
913 */
914 ret = consumer_send_status_channel(sock, channel);
915 if (ret < 0) {
916 /*
917 * There is probably a problem on the socket so the poll will get
918 * it and clean everything up.
919 */
920 goto end_nosignal;
921 }
922
923 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
924 ret = consumer_metadata_cache_allocate(channel);
925 if (ret < 0) {
926 ERR("Allocating metadata cache");
927 goto end_channel_error;
928 }
929 consumer_timer_switch_start(channel, attr.switch_timer_interval);
930 attr.switch_timer_interval = 0;
931 }
932
933 break;
934 }
935 case LTTNG_CONSUMER_GET_CHANNEL:
936 {
937 int ret, relayd_err = 0;
938 uint64_t key = msg.u.get_channel.key;
939 struct lttng_consumer_channel *channel;
940
941 channel = consumer_find_channel(key);
942 if (!channel) {
943 ERR("UST consumer get channel key %lu not found", key);
944 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
945 goto end_msg_sessiond;
946 }
947
948 /* Inform sessiond that we are about to send channel and streams. */
949 ret = consumer_send_status_msg(sock, LTTNG_OK);
950 if (ret < 0) {
951 /* Somehow, the session daemon is not responding anymore. */
952 goto end_nosignal;
953 }
954
955 /* Send everything to sessiond. */
956 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
957 if (ret < 0) {
958 if (relayd_err) {
959 /*
960 * We were unable to send to the relayd the stream so avoid
961 * sending back a fatal error to the thread since this is OK
962 * and the consumer can continue its work.
963 */
964 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
965 goto end_msg_sessiond;
966 }
967 /*
968 * The communicaton was broken hence there is a bad state between
969 * the consumer and sessiond so stop everything.
970 */
971 goto error_fatal;
972 }
973
974 ret = send_streams_to_thread(channel, ctx);
975 if (ret < 0) {
976 /*
977 * If we are unable to send the stream to the thread, there is
978 * a big problem so just stop everything.
979 */
980 goto error_fatal;
981 }
982 /* List MUST be empty after or else it could be reused. */
983 assert(cds_list_empty(&channel->streams.head));
984
985 goto end_msg_sessiond;
986 }
987 case LTTNG_CONSUMER_DESTROY_CHANNEL:
988 {
989 uint64_t key = msg.u.destroy_channel.key;
990 struct lttng_consumer_channel *channel;
991
992 channel = consumer_find_channel(key);
993 if (!channel) {
994 ERR("UST consumer get channel key %lu not found", key);
995 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
996 goto end_msg_sessiond;
997 }
998
999 destroy_channel(channel);
1000
1001 goto end_msg_sessiond;
1002 }
1003 case LTTNG_CONSUMER_CLOSE_METADATA:
1004 {
1005 int ret;
1006
1007 ret = close_metadata(msg.u.close_metadata.key);
1008 if (ret != 0) {
1009 ret_code = ret;
1010 }
1011
1012 goto end_msg_sessiond;
1013 }
1014 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1015 {
1016 int ret;
1017
1018 ret = flush_channel(msg.u.flush_channel.key);
1019 if (ret != 0) {
1020 ret_code = ret;
1021 }
1022
1023 goto end_msg_sessiond;
1024 }
1025 case LTTNG_CONSUMER_PUSH_METADATA:
1026 {
1027 int ret;
1028 uint64_t len = msg.u.push_metadata.len;
1029 uint64_t key = msg.u.push_metadata.key;
1030 uint64_t offset = msg.u.push_metadata.target_offset;
1031 struct lttng_consumer_channel *channel;
1032
1033 DBG("UST consumer push metadata key %lu of len %lu", key, len);
1034
1035 channel = consumer_find_channel(key);
1036 if (!channel) {
1037 ERR("UST consumer push metadata %lu not found", key);
1038 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1039 }
1040
1041 /* Tell session daemon we are ready to receive the metadata. */
1042 ret = consumer_send_status_msg(sock, LTTNG_OK);
1043 if (ret < 0) {
1044 /* Somehow, the session daemon is not responding anymore. */
1045 goto error_fatal;
1046 }
1047
1048 /* Wait for more data. */
1049 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
1050 goto end_nosignal;
1051 }
1052
1053 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1054 len, channel);
1055 if (ret < 0) {
1056 /* error receiving from sessiond */
1057 goto end_nosignal;
1058 } else {
1059 ret_code = ret;
1060 goto end_msg_sessiond;
1061 }
1062 }
1063 case LTTNG_CONSUMER_SETUP_METADATA:
1064 {
1065 int ret;
1066
1067 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1068 if (ret) {
1069 ret_code = ret;
1070 }
1071 goto end_msg_sessiond;
1072 }
1073 default:
1074 break;
1075 }
1076
1077 end_nosignal:
1078 rcu_read_unlock();
1079
1080 /*
1081 * Return 1 to indicate success since the 0 value can be a socket
1082 * shutdown during the recv() or send() call.
1083 */
1084 return 1;
1085
1086 end_msg_sessiond:
1087 /*
1088 * The returned value here is not useful since either way we'll return 1 to
1089 * the caller because the session daemon socket management is done
1090 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1091 */
1092 (void) consumer_send_status_msg(sock, ret_code);
1093 rcu_read_unlock();
1094 return 1;
1095 end_channel_error:
1096 if (channel) {
1097 /*
1098 * Free channel here since no one has a reference to it. We don't
1099 * free after that because a stream can store this pointer.
1100 */
1101 destroy_channel(channel);
1102 }
1103 /* We have to send a status channel message indicating an error. */
1104 ret = consumer_send_status_channel(sock, NULL);
1105 if (ret < 0) {
1106 /* Stop everything if session daemon can not be notified. */
1107 goto error_fatal;
1108 }
1109 rcu_read_unlock();
1110 return 1;
1111 error_fatal:
1112 rcu_read_unlock();
1113 /* This will issue a consumer stop. */
1114 return -1;
1115 }
1116
1117 /*
1118 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1119 * compiled out, we isolate it in this library.
1120 */
1121 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1122 unsigned long *off)
1123 {
1124 assert(stream);
1125 assert(stream->ustream);
1126
1127 return ustctl_get_mmap_read_offset(stream->ustream, off);
1128 }
1129
1130 /*
1131 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1132 * compiled out, we isolate it in this library.
1133 */
1134 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1135 {
1136 assert(stream);
1137 assert(stream->ustream);
1138
1139 return ustctl_get_mmap_base(stream->ustream);
1140 }
1141
1142 /*
1143 * Take a snapshot for a specific fd
1144 *
1145 * Returns 0 on success, < 0 on error
1146 */
1147 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1148 {
1149 assert(stream);
1150 assert(stream->ustream);
1151
1152 return ustctl_snapshot(stream->ustream);
1153 }
1154
1155 /*
1156 * Get the produced position
1157 *
1158 * Returns 0 on success, < 0 on error
1159 */
1160 int lttng_ustconsumer_get_produced_snapshot(
1161 struct lttng_consumer_stream *stream, unsigned long *pos)
1162 {
1163 assert(stream);
1164 assert(stream->ustream);
1165 assert(pos);
1166
1167 return ustctl_snapshot_get_produced(stream->ustream, pos);
1168 }
1169
1170 /*
1171 * Called when the stream signal the consumer that it has hang up.
1172 */
1173 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1174 {
1175 assert(stream);
1176 assert(stream->ustream);
1177
1178 ustctl_flush_buffer(stream->ustream, 0);
1179 stream->hangup_flush_done = 1;
1180 }
1181
1182 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1183 {
1184 assert(chan);
1185 assert(chan->uchan);
1186
1187 ustctl_destroy_channel(chan->uchan);
1188 }
1189
1190 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1191 {
1192 assert(stream);
1193 assert(stream->ustream);
1194
1195 ustctl_destroy_stream(stream->ustream);
1196 }
1197
1198 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1199 struct lttng_consumer_local_data *ctx)
1200 {
1201 unsigned long len, subbuf_size, padding;
1202 int err;
1203 long ret = 0;
1204 char dummy;
1205 struct ustctl_consumer_stream *ustream;
1206
1207 assert(stream);
1208 assert(stream->ustream);
1209 assert(ctx);
1210
1211 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1212 stream->name);
1213
1214 /* Ease our life for what's next. */
1215 ustream = stream->ustream;
1216
1217 /* We can consume the 1 byte written into the wait_fd by UST */
1218 if (!stream->hangup_flush_done) {
1219 ssize_t readlen;
1220
1221 do {
1222 readlen = read(stream->wait_fd, &dummy, 1);
1223 } while (readlen == -1 && errno == EINTR);
1224 if (readlen == -1) {
1225 ret = readlen;
1226 goto end;
1227 }
1228 }
1229
1230 /* Get the next subbuffer */
1231 err = ustctl_get_next_subbuf(ustream);
1232 if (err != 0) {
1233 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1234 /*
1235 * This is a debug message even for single-threaded consumer,
1236 * because poll() have more relaxed criterions than get subbuf,
1237 * so get_subbuf may fail for short race windows where poll()
1238 * would issue wakeups.
1239 */
1240 DBG("Reserving sub buffer failed (everything is normal, "
1241 "it is due to concurrency) [ret: %d]", err);
1242 goto end;
1243 }
1244 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1245 /* Get the full padded subbuffer size */
1246 err = ustctl_get_padded_subbuf_size(ustream, &len);
1247 assert(err == 0);
1248
1249 /* Get subbuffer data size (without padding) */
1250 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1251 assert(err == 0);
1252
1253 /* Make sure we don't get a subbuffer size bigger than the padded */
1254 assert(len >= subbuf_size);
1255
1256 padding = len - subbuf_size;
1257 /* write the subbuffer to the tracefile */
1258 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
1259 /*
1260 * The mmap operation should write subbuf_size amount of data when network
1261 * streaming or the full padding (len) size when we are _not_ streaming.
1262 */
1263 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1264 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
1265 /*
1266 * Display the error but continue processing to try to release the
1267 * subbuffer. This is a DBG statement since any unexpected kill or
1268 * signal, the application gets unregistered, relayd gets closed or
1269 * anything that affects the buffer lifetime will trigger this error.
1270 * So, for the sake of the user, don't print this error since it can
1271 * happen and it is OK with the code flow.
1272 */
1273 DBG("Error writing to tracefile "
1274 "(ret: %zd != len: %lu != subbuf_size: %lu)",
1275 ret, len, subbuf_size);
1276 }
1277 err = ustctl_put_next_subbuf(ustream);
1278 assert(err == 0);
1279
1280 end:
1281 return ret;
1282 }
1283
1284 /*
1285 * Called when a stream is created.
1286 */
1287 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
1288 {
1289 return lttng_create_output_file(stream);
1290 }
1291
1292 /*
1293 * Check if data is still being extracted from the buffers for a specific
1294 * stream. Consumer data lock MUST be acquired before calling this function
1295 * and the stream lock.
1296 *
1297 * Return 1 if the traced data are still getting read else 0 meaning that the
1298 * data is available for trace viewer reading.
1299 */
1300 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
1301 {
1302 int ret;
1303
1304 assert(stream);
1305 assert(stream->ustream);
1306
1307 DBG("UST consumer checking data pending");
1308
1309 ret = ustctl_get_next_subbuf(stream->ustream);
1310 if (ret == 0) {
1311 /* There is still data so let's put back this subbuffer. */
1312 ret = ustctl_put_subbuf(stream->ustream);
1313 assert(ret == 0);
1314 ret = 1; /* Data is pending */
1315 goto end;
1316 }
1317
1318 /* Data is NOT pending so ready to be read. */
1319 ret = 0;
1320
1321 end:
1322 return ret;
1323 }
1324
1325 /*
1326 * Close every metadata stream wait fd of the metadata hash table. This
1327 * function MUST be used very carefully so not to run into a race between the
1328 * metadata thread handling streams and this function closing their wait fd.
1329 *
1330 * For UST, this is used when the session daemon hangs up. Its the metadata
1331 * producer so calling this is safe because we are assured that no state change
1332 * can occur in the metadata thread for the streams in the hash table.
1333 */
1334 void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
1335 {
1336 int ret;
1337 struct lttng_ht_iter iter;
1338 struct lttng_consumer_stream *stream;
1339
1340 assert(metadata_ht);
1341 assert(metadata_ht->ht);
1342
1343 DBG("UST consumer closing all metadata streams");
1344
1345 rcu_read_lock();
1346 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
1347 node.node) {
1348 int fd = stream->wait_fd;
1349
1350 /*
1351 * Whatever happens here we have to continue to try to close every
1352 * streams. Let's report at least the error on failure.
1353 */
1354 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1355 if (ret) {
1356 ERR("Unable to close metadata stream fd %d ret %d", fd, ret);
1357 }
1358 DBG("Metadata wait fd %d closed", fd);
1359 }
1360 rcu_read_unlock();
1361 }
1362
1363 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
1364 {
1365 int ret;
1366
1367 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1368 if (ret < 0) {
1369 ERR("Unable to close wakeup fd");
1370 }
1371 }
1372
1373 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
1374 struct lttng_consumer_channel *channel)
1375 {
1376 struct lttcomm_metadata_request_msg request;
1377 struct lttcomm_consumer_msg msg;
1378 enum lttng_error_code ret_code = LTTNG_OK;
1379 uint64_t len, key, offset;
1380 int ret;
1381
1382 assert(channel);
1383 assert(channel->metadata_cache);
1384
1385 /* send the metadata request to sessiond */
1386 switch (consumer_data.type) {
1387 case LTTNG_CONSUMER64_UST:
1388 request.bits_per_long = 64;
1389 break;
1390 case LTTNG_CONSUMER32_UST:
1391 request.bits_per_long = 32;
1392 break;
1393 default:
1394 request.bits_per_long = 0;
1395 break;
1396 }
1397
1398 request.session_id = channel->session_id;
1399 request.uid = channel->uid;
1400 request.key = channel->key;
1401 DBG("Sending metadata request to sessiond, session %" PRIu64,
1402 channel->session_id);
1403
1404 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
1405 sizeof(request));
1406 if (ret < 0) {
1407 ERR("Asking metadata to sessiond");
1408 goto end;
1409 }
1410
1411 /* Receive the metadata from sessiond */
1412 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
1413 sizeof(msg));
1414 if (ret != sizeof(msg)) {
1415 DBG("Consumer received unexpected message size %d (expects %lu)",
1416 ret, sizeof(msg));
1417 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1418 /*
1419 * The ret value might 0 meaning an orderly shutdown but this is ok
1420 * since the caller handles this.
1421 */
1422 goto end;
1423 }
1424
1425 if (msg.cmd_type == LTTNG_ERR_UND) {
1426 /* No registry found */
1427 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
1428 ret_code);
1429 ret = 0;
1430 goto end;
1431 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
1432 ERR("Unexpected cmd_type received %d", msg.cmd_type);
1433 ret = -1;
1434 goto end;
1435 }
1436
1437 len = msg.u.push_metadata.len;
1438 key = msg.u.push_metadata.key;
1439 offset = msg.u.push_metadata.target_offset;
1440
1441 assert(key == channel->key);
1442 if (len == 0) {
1443 DBG("No new metadata to receive for key %" PRIu64, key);
1444 }
1445
1446 /* Tell session daemon we are ready to receive the metadata. */
1447 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
1448 LTTNG_OK);
1449 if (ret < 0 || len == 0) {
1450 /*
1451 * Somehow, the session daemon is not responding anymore or there is
1452 * nothing to receive.
1453 */
1454 goto end;
1455 }
1456
1457 ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
1458 key, offset, len, channel);
1459 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
1460 ret = 0;
1461
1462 end:
1463 return ret;
1464 }
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