Cleanup: useless reset of ret to zero
[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c
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1/*
2 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18#define _LGPL_SOURCE
19#include <lttng/trigger/trigger.h>
20#include <lttng/notification/channel-internal.h>
21#include <lttng/notification/notification-internal.h>
22#include <lttng/condition/condition-internal.h>
23#include <lttng/condition/buffer-usage-internal.h>
24#include <common/error.h>
25#include <common/config/session-config.h>
26#include <common/defaults.h>
27#include <common/utils.h>
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28#include <common/align.h>
29#include <common/time.h>
30#include <sys/eventfd.h>
31#include <sys/stat.h>
32#include <time.h>
33#include <signal.h>
34
35#include "notification-thread.h"
36#include "notification-thread-events.h"
37#include "notification-thread-commands.h"
38#include "lttng-sessiond.h"
39#include "health-sessiond.h"
40
41#include <urcu.h>
42#include <urcu/list.h>
43#include <urcu/rculfhash.h>
44
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45/*
46 * Destroy the thread data previously created by the init function.
47 */
48void notification_thread_handle_destroy(
49 struct notification_thread_handle *handle)
50{
51 int ret;
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52
53 if (!handle) {
54 goto end;
55 }
56
57 if (handle->cmd_queue.event_fd < 0) {
58 goto end;
59 }
60 ret = close(handle->cmd_queue.event_fd);
61 if (ret < 0) {
62 PERROR("close notification command queue event_fd");
63 }
64
8ada111f 65 assert(cds_list_empty(&handle->cmd_queue.list));
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66 pthread_mutex_destroy(&handle->cmd_queue.lock);
67
68 if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
69 ret = close(handle->channel_monitoring_pipes.ust32_consumer);
70 if (ret) {
71 PERROR("close 32-bit consumer channel monitoring pipe");
72 }
73 }
74 if (handle->channel_monitoring_pipes.ust64_consumer >= 0) {
75 ret = close(handle->channel_monitoring_pipes.ust64_consumer);
76 if (ret) {
77 PERROR("close 64-bit consumer channel monitoring pipe");
78 }
79 }
80 if (handle->channel_monitoring_pipes.kernel_consumer >= 0) {
81 ret = close(handle->channel_monitoring_pipes.kernel_consumer);
82 if (ret) {
83 PERROR("close kernel consumer channel monitoring pipe");
84 }
85 }
86end:
87 free(handle);
88}
89
90struct notification_thread_handle *notification_thread_handle_create(
91 struct lttng_pipe *ust32_channel_monitor_pipe,
92 struct lttng_pipe *ust64_channel_monitor_pipe,
93 struct lttng_pipe *kernel_channel_monitor_pipe)
94{
95 int ret;
96 struct notification_thread_handle *handle;
97
98 handle = zmalloc(sizeof(*handle));
99 if (!handle) {
100 goto end;
101 }
102
103 /* FIXME Replace eventfd by a pipe to support older kernels. */
d72c8834 104 handle->cmd_queue.event_fd = eventfd(0, EFD_CLOEXEC | EFD_SEMAPHORE);
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105 if (handle->cmd_queue.event_fd < 0) {
106 PERROR("eventfd notification command queue");
107 goto error;
108 }
109 CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
110 ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
111 if (ret) {
112 goto error;
113 }
114
115 if (ust32_channel_monitor_pipe) {
116 handle->channel_monitoring_pipes.ust32_consumer =
117 lttng_pipe_release_readfd(
118 ust32_channel_monitor_pipe);
119 if (handle->channel_monitoring_pipes.ust32_consumer < 0) {
120 goto error;
121 }
122 } else {
123 handle->channel_monitoring_pipes.ust32_consumer = -1;
124 }
125 if (ust64_channel_monitor_pipe) {
126 handle->channel_monitoring_pipes.ust64_consumer =
127 lttng_pipe_release_readfd(
128 ust64_channel_monitor_pipe);
129 if (handle->channel_monitoring_pipes.ust64_consumer < 0) {
130 goto error;
131 }
132 } else {
133 handle->channel_monitoring_pipes.ust64_consumer = -1;
134 }
135 if (kernel_channel_monitor_pipe) {
136 handle->channel_monitoring_pipes.kernel_consumer =
137 lttng_pipe_release_readfd(
138 kernel_channel_monitor_pipe);
139 if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
140 goto error;
141 }
142 } else {
143 handle->channel_monitoring_pipes.kernel_consumer = -1;
144 }
145end:
146 return handle;
147error:
148 notification_thread_handle_destroy(handle);
149 return NULL;
150}
151
152static
153char *get_notification_channel_sock_path(void)
154{
155 int ret;
156 bool is_root = !getuid();
157 char *sock_path;
158
159 sock_path = zmalloc(LTTNG_PATH_MAX);
160 if (!sock_path) {
161 goto error;
162 }
163
164 if (is_root) {
165 ret = snprintf(sock_path, LTTNG_PATH_MAX,
166 DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
167 if (ret < 0) {
168 goto error;
169 }
170 } else {
171 char *home_path = utils_get_home_dir();
172
173 if (!home_path) {
174 ERR("Can't get HOME directory for socket creation");
175 goto error;
176 }
177
178 ret = snprintf(sock_path, LTTNG_PATH_MAX,
179 DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
180 home_path);
181 if (ret < 0) {
182 goto error;
183 }
184 }
185
186 return sock_path;
187error:
188 free(sock_path);
189 return NULL;
190}
191
192static
193void notification_channel_socket_destroy(int fd)
194{
195 int ret;
196 char *sock_path = get_notification_channel_sock_path();
197
198 DBG("[notification-thread] Destroying notification channel socket");
199
200 if (sock_path) {
201 ret = unlink(sock_path);
202 free(sock_path);
203 if (ret < 0) {
204 PERROR("unlink notification channel socket");
205 }
206 }
207
208 ret = close(fd);
209 if (ret) {
210 PERROR("close notification channel socket");
211 }
212}
213
214static
215int notification_channel_socket_create(void)
216{
217 int fd = -1, ret;
218 char *sock_path = get_notification_channel_sock_path();
219
220 DBG("[notification-thread] Creating notification channel UNIX socket at %s",
221 sock_path);
222
223 ret = lttcomm_create_unix_sock(sock_path);
224 if (ret < 0) {
225 ERR("[notification-thread] Failed to create notification socket");
226 goto error;
227 }
228 fd = ret;
229
230 ret = chmod(sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
231 if (ret < 0) {
232 ERR("Set file permissions failed: %s", sock_path);
233 PERROR("chmod notification channel socket");
234 goto error;
235 }
236
237 if (getuid() == 0) {
238 ret = chown(sock_path, 0,
239 utils_get_group_id(tracing_group_name));
240 if (ret) {
241 ERR("Failed to set the notification channel socket's group");
242 ret = -1;
243 goto error;
244 }
245 }
246
247 DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
248 fd);
249 free(sock_path);
250 return fd;
251error:
252 if (fd >= 0 && close(fd) < 0) {
253 PERROR("close notification channel socket");
254 }
255 free(sock_path);
256 return ret;
257}
258
259static
260int init_poll_set(struct lttng_poll_event *poll_set,
261 struct notification_thread_handle *handle,
262 int notification_channel_socket)
263{
264 int ret;
265
266 /*
267 * Create pollset with size 5:
268 * - notification channel socket (listen for new connections),
269 * - command queue event fd (internal sessiond commands),
270 * - consumerd (32-bit user space) channel monitor pipe,
271 * - consumerd (64-bit user space) channel monitor pipe,
272 * - consumerd (kernel) channel monitor pipe.
273 */
274 ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
275 if (ret < 0) {
276 goto end;
277 }
278
279 ret = lttng_poll_add(poll_set, notification_channel_socket,
280 LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
281 if (ret < 0) {
282 ERR("[notification-thread] Failed to add notification channel socket to pollset");
283 goto error;
284 }
285 ret = lttng_poll_add(poll_set, handle->cmd_queue.event_fd,
286 LPOLLIN | LPOLLERR);
287 if (ret < 0) {
288 ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
289 goto error;
290 }
291 ret = lttng_poll_add(poll_set,
292 handle->channel_monitoring_pipes.ust32_consumer,
293 LPOLLIN | LPOLLERR);
294 if (ret < 0) {
295 ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset");
296 goto error;
297 }
298 ret = lttng_poll_add(poll_set,
299 handle->channel_monitoring_pipes.ust64_consumer,
300 LPOLLIN | LPOLLERR);
301 if (ret < 0) {
302 ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset");
303 goto error;
304 }
305 if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
306 goto end;
307 }
308 ret = lttng_poll_add(poll_set,
309 handle->channel_monitoring_pipes.kernel_consumer,
310 LPOLLIN | LPOLLERR);
311 if (ret < 0) {
312 ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
313 goto error;
314 }
315end:
316 return ret;
317error:
318 lttng_poll_clean(poll_set);
319 return ret;
320}
321
322static
323void fini_thread_state(struct notification_thread_state *state)
324{
325 int ret;
326
327 if (state->client_socket_ht) {
328 ret = handle_notification_thread_client_disconnect_all(state);
329 assert(!ret);
330 ret = cds_lfht_destroy(state->client_socket_ht, NULL);
331 assert(!ret);
332 }
333 if (state->triggers_ht) {
334 ret = handle_notification_thread_trigger_unregister_all(state);
335 assert(!ret);
336 ret = cds_lfht_destroy(state->triggers_ht, NULL);
337 assert(!ret);
338 }
339 if (state->channel_triggers_ht) {
340 ret = cds_lfht_destroy(state->channel_triggers_ht, NULL);
341 assert(!ret);
342 }
343 if (state->channel_state_ht) {
344 ret = cds_lfht_destroy(state->channel_state_ht, NULL);
345 assert(!ret);
346 }
347 if (state->notification_trigger_clients_ht) {
348 ret = cds_lfht_destroy(state->notification_trigger_clients_ht,
349 NULL);
350 assert(!ret);
351 }
352 if (state->channels_ht) {
353 ret = cds_lfht_destroy(state->channels_ht,
354 NULL);
355 assert(!ret);
356 }
357
358 if (state->notification_channel_socket >= 0) {
359 notification_channel_socket_destroy(
360 state->notification_channel_socket);
361 }
362 lttng_poll_clean(&state->events);
363}
364
365static
366int init_thread_state(struct notification_thread_handle *handle,
367 struct notification_thread_state *state)
368{
369 int ret;
370
371 memset(state, 0, sizeof(*state));
372 state->notification_channel_socket = -1;
373 lttng_poll_init(&state->events);
374
375 ret = notification_channel_socket_create();
376 if (ret < 0) {
377 goto end;
378 }
379 state->notification_channel_socket = ret;
380
381 ret = init_poll_set(&state->events, handle,
382 state->notification_channel_socket);
383 if (ret) {
384 goto end;
385 }
386
387 DBG("[notification-thread] Listening on notification channel socket");
388 ret = lttcomm_listen_unix_sock(state->notification_channel_socket);
389 if (ret < 0) {
390 ERR("[notification-thread] Listen failed on notification channel socket");
391 goto error;
392 }
393
394 state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
395 CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
396 if (!state->client_socket_ht) {
397 goto error;
398 }
399
400 state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
401 CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
402 if (!state->channel_triggers_ht) {
403 goto error;
404 }
405
406 state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
407 CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
408 if (!state->channel_state_ht) {
409 goto error;
410 }
411
412 state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE,
413 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
414 if (!state->notification_trigger_clients_ht) {
415 goto error;
416 }
417
418 state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE,
419 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
420 if (!state->channels_ht) {
421 goto error;
422 }
423
424 state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
425 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
426 if (!state->triggers_ht) {
427 goto error;
428 }
429end:
430 return 0;
431error:
432 fini_thread_state(state);
433 return -1;
434}
435
436static
437int handle_channel_monitoring_pipe(int fd, uint32_t revents,
438 struct notification_thread_handle *handle,
439 struct notification_thread_state *state)
440{
441 int ret = 0;
442 enum lttng_domain_type domain;
443
444 if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
445 fd == handle->channel_monitoring_pipes.ust64_consumer) {
446 domain = LTTNG_DOMAIN_UST;
447 } else if (fd == handle->channel_monitoring_pipes.kernel_consumer) {
448 domain = LTTNG_DOMAIN_KERNEL;
449 } else {
450 abort();
451 }
452
453 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
454 ret = lttng_poll_del(&state->events, fd);
455 if (ret) {
456 ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set");
457 }
458 goto end;
459 }
460
461 ret = handle_notification_thread_channel_sample(
462 state, fd, domain);
463 if (ret) {
4149ace8 464 ERR("[notification-thread] Consumer sample handling error occurred");
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465 ret = -1;
466 goto end;
467 }
468end:
469 return ret;
470}
471
472/*
473 * This thread services notification channel clients and commands received
474 * from various lttng-sessiond components over a command queue.
475 */
476void *thread_notification(void *data)
477{
478 int ret;
479 struct notification_thread_handle *handle = data;
480 struct notification_thread_state state;
481
482 DBG("[notification-thread] Started notification thread");
483
484 if (!handle) {
485 ERR("[notification-thread] Invalid thread context provided");
486 goto end;
487 }
488
489 rcu_register_thread();
490 rcu_thread_online();
491
492 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
493 health_code_update();
494
495 ret = init_thread_state(handle, &state);
496 if (ret) {
497 goto end;
498 }
499
500 /* Ready to handle client connections. */
501 sessiond_notify_ready();
502
503 while (true) {
504 int fd_count, i;
505
506 health_poll_entry();
507 DBG("[notification-thread] Entering poll wait");
508 ret = lttng_poll_wait(&state.events, -1);
509 DBG("[notification-thread] Poll wait returned (%i)", ret);
510 health_poll_exit();
511 if (ret < 0) {
512 /*
513 * Restart interrupted system call.
514 */
515 if (errno == EINTR) {
516 continue;
517 }
518 ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
519 goto error;
520 }
521
522 fd_count = ret;
523 for (i = 0; i < fd_count; i++) {
524 int fd = LTTNG_POLL_GETFD(&state.events, i);
525 uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
526
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527 if (!revents) {
528 continue;
529 }
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530 DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
531
532 if (fd == state.notification_channel_socket) {
533 if (revents & LPOLLIN) {
534 ret = handle_notification_thread_client_connect(
535 &state);
536 if (ret < 0) {
537 goto error;
538 }
539 } else if (revents &
540 (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
541 ERR("[notification-thread] Notification socket poll error");
542 goto error;
543 } else {
544 ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd);
545 goto error;
546 }
547 } else if (fd == handle->cmd_queue.event_fd) {
548 ret = handle_notification_thread_command(handle,
549 &state);
550 if (ret < 0) {
551 DBG("[notification-thread] Error encountered while servicing command queue");
552 goto error;
553 } else if (ret > 0) {
554 goto exit;
555 }
556 } else if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
557 fd == handle->channel_monitoring_pipes.ust64_consumer ||
558 fd == handle->channel_monitoring_pipes.kernel_consumer) {
559 ret = handle_channel_monitoring_pipe(fd,
560 revents, handle, &state);
561 if (ret) {
562 goto error;
563 }
564 } else {
565 /* Activity on a client's socket. */
566 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
567 /*
568 * It doesn't matter if a command was
569 * pending on the client socket at this
570 * point since it now has no way to
571 * receive the notifications to which
572 * it was subscribing or unsubscribing.
573 */
574 ret = handle_notification_thread_client_disconnect(
575 fd, &state);
576 if (ret) {
577 goto error;
578 }
579 } else {
580 if (revents & LPOLLIN) {
581 ret = handle_notification_thread_client_in(
582 &state, fd);
583 if (ret) {
584 goto error;
585 }
586 }
587
588 if (revents & LPOLLOUT) {
589 ret = handle_notification_thread_client_out(
590 &state, fd);
591 if (ret) {
592 goto error;
593 }
594 }
595 }
596 }
597 }
598 }
599exit:
600error:
601 fini_thread_state(&state);
602 health_unregister(health_sessiond);
603 rcu_thread_offline();
604 rcu_unregister_thread();
605end:
606 return NULL;
607}
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