d52dcb945bfe3cfbbfbd69a29b8f78700ac794f8
[lttng-tools.git] / lttng-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; only version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <grp.h>
23 #include <limits.h>
24 #include <pthread.h>
25 #include <semaphore.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sys/mman.h>
31 #include <sys/mount.h>
32 #include <sys/resource.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 #include <urcu/futex.h>
38 #include <unistd.h>
39 #include <config.h>
40
41 #include <lttng-consumerd.h>
42 #include <lttng-sessiond-comm.h>
43 #include <lttng/lttng-consumer.h>
44
45 #include <lttngerr.h>
46
47 #include "channel.h"
48 #include "compat/poll.h"
49 #include "context.h"
50 #include "event.h"
51 #include "futex.h"
52 #include "hashtable.h"
53 #include "kernel-ctl.h"
54 #include "lttng-sessiond.h"
55 #include "shm.h"
56 #include "ust-app.h"
57 #include "ust-ctl.h"
58 #include "utils.h"
59
60 struct consumer_data {
61 enum lttng_consumer_type type;
62
63 pthread_t thread; /* Worker thread interacting with the consumer */
64 sem_t sem;
65
66 /* Mutex to control consumerd pid assignation */
67 pthread_mutex_t pid_mutex;
68 pid_t pid;
69
70 int err_sock;
71 int cmd_sock;
72
73 /* consumer error and command Unix socket path */
74 char err_unix_sock_path[PATH_MAX];
75 char cmd_unix_sock_path[PATH_MAX];
76 };
77
78 /* Const values */
79 const char default_home_dir[] = DEFAULT_HOME_DIR;
80 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
81 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
82 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
83
84 /* Variables */
85 int opt_verbose; /* Not static for lttngerr.h */
86 int opt_verbose_consumer; /* Not static for lttngerr.h */
87 int opt_quiet; /* Not static for lttngerr.h */
88
89 const char *progname;
90 const char *opt_tracing_group;
91 static int opt_sig_parent;
92 static int opt_daemon;
93 static int is_root; /* Set to 1 if the daemon is running as root */
94 static pid_t ppid; /* Parent PID for --sig-parent option */
95
96 /* Consumer daemon specific control data */
97 static struct consumer_data kconsumer_data = {
98 .type = LTTNG_CONSUMER_KERNEL,
99 };
100 static struct consumer_data ustconsumer_data = {
101 .type = LTTNG_CONSUMER_UST,
102 };
103
104 static int dispatch_thread_exit;
105
106 /* Global application Unix socket path */
107 static char apps_unix_sock_path[PATH_MAX];
108 /* Global client Unix socket path */
109 static char client_unix_sock_path[PATH_MAX];
110 /* global wait shm path for UST */
111 static char wait_shm_path[PATH_MAX];
112
113 /* Sockets and FDs */
114 static int client_sock;
115 static int apps_sock;
116 static int kernel_tracer_fd;
117 static int kernel_poll_pipe[2];
118
119 /*
120 * Quit pipe for all threads. This permits a single cancellation point
121 * for all threads when receiving an event on the pipe.
122 */
123 static int thread_quit_pipe[2];
124
125 /*
126 * This pipe is used to inform the thread managing application communication
127 * that a command is queued and ready to be processed.
128 */
129 static int apps_cmd_pipe[2];
130
131 /* Pthread, Mutexes and Semaphores */
132 static pthread_t apps_thread;
133 static pthread_t reg_apps_thread;
134 static pthread_t client_thread;
135 static pthread_t kernel_thread;
136 static pthread_t dispatch_thread;
137
138
139 /*
140 * UST registration command queue. This queue is tied with a futex and uses a N
141 * wakers / 1 waiter implemented and detailed in futex.c/.h
142 *
143 * The thread_manage_apps and thread_dispatch_ust_registration interact with
144 * this queue and the wait/wake scheme.
145 */
146 static struct ust_cmd_queue ust_cmd_queue;
147
148 /*
149 * Pointer initialized before thread creation.
150 *
151 * This points to the tracing session list containing the session count and a
152 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
153 * MUST NOT be taken if you call a public function in session.c.
154 *
155 * The lock is nested inside the structure: session_list_ptr->lock. Please use
156 * session_lock_list and session_unlock_list for lock acquisition.
157 */
158 static struct ltt_session_list *session_list_ptr;
159
160 /*
161 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
162 */
163 static int create_thread_poll_set(struct lttng_poll_event *events,
164 unsigned int size)
165 {
166 int ret;
167
168 if (events == NULL || size == 0) {
169 ret = -1;
170 goto error;
171 }
172
173 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
174 if (ret < 0) {
175 goto error;
176 }
177
178 /* Add quit pipe */
179 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
180 if (ret < 0) {
181 goto error;
182 }
183
184 return 0;
185
186 error:
187 return ret;
188 }
189
190 /*
191 * Check if the thread quit pipe was triggered.
192 *
193 * Return 1 if it was triggered else 0;
194 */
195 static int check_thread_quit_pipe(int fd, uint32_t events)
196 {
197 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
198 return 1;
199 }
200
201 return 0;
202 }
203
204 /*
205 * Remove modules in reverse load order.
206 */
207 static int modprobe_remove_kernel_modules(void)
208 {
209 int ret = 0, i;
210 char modprobe[256];
211
212 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
213 ret = snprintf(modprobe, sizeof(modprobe),
214 "/sbin/modprobe -r -q %s",
215 kernel_modules_list[i].name);
216 if (ret < 0) {
217 perror("snprintf modprobe -r");
218 goto error;
219 }
220 modprobe[sizeof(modprobe) - 1] = '\0';
221 ret = system(modprobe);
222 if (ret == -1) {
223 ERR("Unable to launch modprobe -r for module %s",
224 kernel_modules_list[i].name);
225 } else if (kernel_modules_list[i].required
226 && WEXITSTATUS(ret) != 0) {
227 ERR("Unable to remove module %s",
228 kernel_modules_list[i].name);
229 } else {
230 DBG("Modprobe removal successful %s",
231 kernel_modules_list[i].name);
232 }
233 }
234
235 error:
236 return ret;
237 }
238
239 /*
240 * Return group ID of the tracing group or -1 if not found.
241 */
242 static gid_t allowed_group(void)
243 {
244 struct group *grp;
245
246 if (opt_tracing_group) {
247 grp = getgrnam(opt_tracing_group);
248 } else {
249 grp = getgrnam(default_tracing_group);
250 }
251 if (!grp) {
252 return -1;
253 } else {
254 return grp->gr_gid;
255 }
256 }
257
258 /*
259 * Init thread quit pipe.
260 *
261 * Return -1 on error or 0 if all pipes are created.
262 */
263 static int init_thread_quit_pipe(void)
264 {
265 int ret;
266
267 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
268 if (ret < 0) {
269 perror("thread quit pipe");
270 goto error;
271 }
272
273 error:
274 return ret;
275 }
276
277 /*
278 * Complete teardown of a kernel session. This free all data structure related
279 * to a kernel session and update counter.
280 */
281 static void teardown_kernel_session(struct ltt_session *session)
282 {
283 if (session->kernel_session != NULL) {
284 DBG("Tearing down kernel session");
285
286 /*
287 * If a custom kernel consumer was registered, close the socket before
288 * tearing down the complete kernel session structure
289 */
290 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
291 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
292 }
293
294 trace_kernel_destroy_session(session->kernel_session);
295 /* Extra precaution */
296 session->kernel_session = NULL;
297 }
298 }
299
300 /*
301 * Complete teardown of all UST sessions. This will free everything on his path
302 * and destroy the core essence of all ust sessions :)
303 */
304 static void teardown_ust_session(struct ltt_session *session)
305 {
306 DBG("Tearing down UST session(s)");
307
308 trace_ust_destroy_session(session->ust_session);
309 }
310
311 /*
312 * Stop all threads by closing the thread quit pipe.
313 */
314 static void stop_threads(void)
315 {
316 int ret;
317
318 /* Stopping all threads */
319 DBG("Terminating all threads");
320 ret = notify_thread_pipe(thread_quit_pipe[1]);
321 if (ret < 0) {
322 ERR("write error on thread quit pipe");
323 }
324
325 /* Dispatch thread */
326 dispatch_thread_exit = 1;
327 futex_nto1_wake(&ust_cmd_queue.futex);
328 }
329
330 /*
331 * Cleanup the daemon
332 */
333 static void cleanup(void)
334 {
335 int ret;
336 char *cmd;
337 struct ltt_session *sess, *stmp;
338
339 DBG("Cleaning up");
340
341 if (is_root) {
342 DBG("Removing %s directory", LTTNG_RUNDIR);
343 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
344 if (ret < 0) {
345 ERR("asprintf failed. Something is really wrong!");
346 }
347
348 /* Remove lttng run directory */
349 ret = system(cmd);
350 if (ret < 0) {
351 ERR("Unable to clean " LTTNG_RUNDIR);
352 }
353 }
354
355 DBG("Cleaning up all session");
356
357 /* Destroy session list mutex */
358 if (session_list_ptr != NULL) {
359 pthread_mutex_destroy(&session_list_ptr->lock);
360
361 /* Cleanup ALL session */
362 cds_list_for_each_entry_safe(sess, stmp,
363 &session_list_ptr->head, list) {
364 teardown_kernel_session(sess);
365 teardown_ust_session(sess);
366 free(sess);
367 }
368 }
369
370 DBG("Closing all UST sockets");
371 ust_app_clean_list();
372
373 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
374
375 DBG("Closing kernel fd");
376 close(kernel_tracer_fd);
377
378 if (is_root) {
379 DBG("Unloading kernel modules");
380 modprobe_remove_kernel_modules();
381 }
382
383 close(thread_quit_pipe[0]);
384 close(thread_quit_pipe[1]);
385
386 /* <fun> */
387 MSG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
388 "Matthew, BEET driven development works!%c[%dm",
389 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
390 /* </fun> */
391 }
392
393 /*
394 * Send data on a unix socket using the liblttsessiondcomm API.
395 *
396 * Return lttcomm error code.
397 */
398 static int send_unix_sock(int sock, void *buf, size_t len)
399 {
400 /* Check valid length */
401 if (len <= 0) {
402 return -1;
403 }
404
405 return lttcomm_send_unix_sock(sock, buf, len);
406 }
407
408 /*
409 * Free memory of a command context structure.
410 */
411 static void clean_command_ctx(struct command_ctx **cmd_ctx)
412 {
413 DBG("Clean command context structure");
414 if (*cmd_ctx) {
415 if ((*cmd_ctx)->llm) {
416 free((*cmd_ctx)->llm);
417 }
418 if ((*cmd_ctx)->lsm) {
419 free((*cmd_ctx)->lsm);
420 }
421 free(*cmd_ctx);
422 *cmd_ctx = NULL;
423 }
424 }
425
426 /*
427 * Send all stream fds of kernel channel to the consumer.
428 */
429 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
430 int sock, struct ltt_kernel_channel *channel)
431 {
432 int ret;
433 struct ltt_kernel_stream *stream;
434 struct lttcomm_consumer_msg lkm;
435
436 DBG("Sending streams of channel %s to kernel consumer",
437 channel->channel->name);
438
439 /* Send channel */
440 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
441 lkm.u.channel.channel_key = channel->fd;
442 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
443 lkm.u.channel.mmap_len = 0; /* for kernel */
444 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
445 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
446 if (ret < 0) {
447 perror("send consumer channel");
448 goto error;
449 }
450
451 /* Send streams */
452 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
453 if (!stream->fd) {
454 continue;
455 }
456 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
457 lkm.u.stream.channel_key = channel->fd;
458 lkm.u.stream.stream_key = stream->fd;
459 lkm.u.stream.state = stream->state;
460 lkm.u.stream.output = channel->channel->attr.output;
461 lkm.u.stream.mmap_len = 0; /* for kernel */
462 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
463 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
464 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
465 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
466 if (ret < 0) {
467 perror("send consumer stream");
468 goto error;
469 }
470 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
471 if (ret < 0) {
472 perror("send consumer stream ancillary data");
473 goto error;
474 }
475 }
476
477 DBG("consumer channel streams sent");
478
479 return 0;
480
481 error:
482 return ret;
483 }
484
485 /*
486 * Send all stream fds of the kernel session to the consumer.
487 */
488 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
489 struct ltt_kernel_session *session)
490 {
491 int ret;
492 struct ltt_kernel_channel *chan;
493 struct lttcomm_consumer_msg lkm;
494 int sock = session->consumer_fd;
495
496 DBG("Sending metadata stream fd");
497
498 /* Extra protection. It's NOT supposed to be set to 0 at this point */
499 if (session->consumer_fd == 0) {
500 session->consumer_fd = consumer_data->cmd_sock;
501 }
502
503 if (session->metadata_stream_fd != 0) {
504 /* Send metadata channel fd */
505 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
506 lkm.u.channel.channel_key = session->metadata->fd;
507 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
508 lkm.u.channel.mmap_len = 0; /* for kernel */
509 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
510 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
511 if (ret < 0) {
512 perror("send consumer channel");
513 goto error;
514 }
515
516 /* Send metadata stream fd */
517 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
518 lkm.u.stream.channel_key = session->metadata->fd;
519 lkm.u.stream.stream_key = session->metadata_stream_fd;
520 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
521 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
522 lkm.u.stream.mmap_len = 0; /* for kernel */
523 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
524 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
525 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
526 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
527 if (ret < 0) {
528 perror("send consumer stream");
529 goto error;
530 }
531 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
532 if (ret < 0) {
533 perror("send consumer stream");
534 goto error;
535 }
536 }
537
538 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
539 ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
540 if (ret < 0) {
541 goto error;
542 }
543 }
544
545 DBG("consumer fds (metadata and channel streams) sent");
546
547 return 0;
548
549 error:
550 return ret;
551 }
552
553 /*
554 * Notify UST applications using the shm mmap futex.
555 */
556 static int notify_ust_apps(int active)
557 {
558 char *wait_shm_mmap;
559
560 DBG("Notifying applications of session daemon state: %d", active);
561
562 /* See shm.c for this call implying mmap, shm and futex calls */
563 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
564 if (wait_shm_mmap == NULL) {
565 goto error;
566 }
567
568 /* Wake waiting process */
569 futex_wait_update((int32_t *) wait_shm_mmap, active);
570
571 /* Apps notified successfully */
572 return 0;
573
574 error:
575 return -1;
576 }
577
578 /*
579 * Setup the outgoing data buffer for the response (llm) by allocating the
580 * right amount of memory and copying the original information from the lsm
581 * structure.
582 *
583 * Return total size of the buffer pointed by buf.
584 */
585 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
586 {
587 int ret, buf_size;
588
589 buf_size = size;
590
591 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
592 if (cmd_ctx->llm == NULL) {
593 perror("malloc");
594 ret = -ENOMEM;
595 goto error;
596 }
597
598 /* Copy common data */
599 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
600 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
601
602 cmd_ctx->llm->data_size = size;
603 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
604
605 return buf_size;
606
607 error:
608 return ret;
609 }
610
611 /*
612 * Update the kernel poll set of all channel fd available over all tracing
613 * session. Add the wakeup pipe at the end of the set.
614 */
615 static int update_kernel_poll(struct lttng_poll_event *events)
616 {
617 int ret;
618 struct ltt_session *session;
619 struct ltt_kernel_channel *channel;
620
621 DBG("Updating kernel poll set");
622
623 session_lock_list();
624 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
625 session_lock(session);
626 if (session->kernel_session == NULL) {
627 session_unlock(session);
628 continue;
629 }
630
631 cds_list_for_each_entry(channel,
632 &session->kernel_session->channel_list.head, list) {
633 /* Add channel fd to the kernel poll set */
634 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
635 if (ret < 0) {
636 session_unlock(session);
637 goto error;
638 }
639 DBG("Channel fd %d added to kernel set", channel->fd);
640 }
641 session_unlock(session);
642 }
643 session_unlock_list();
644
645 return 0;
646
647 error:
648 session_unlock_list();
649 return -1;
650 }
651
652 /*
653 * Find the channel fd from 'fd' over all tracing session. When found, check
654 * for new channel stream and send those stream fds to the kernel consumer.
655 *
656 * Useful for CPU hotplug feature.
657 */
658 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
659 {
660 int ret = 0;
661 struct ltt_session *session;
662 struct ltt_kernel_channel *channel;
663
664 DBG("Updating kernel streams for channel fd %d", fd);
665
666 session_lock_list();
667 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
668 session_lock(session);
669 if (session->kernel_session == NULL) {
670 session_unlock(session);
671 continue;
672 }
673
674 /* This is not suppose to be 0 but this is an extra security check */
675 if (session->kernel_session->consumer_fd == 0) {
676 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
677 }
678
679 cds_list_for_each_entry(channel,
680 &session->kernel_session->channel_list.head, list) {
681 if (channel->fd == fd) {
682 DBG("Channel found, updating kernel streams");
683 ret = kernel_open_channel_stream(channel);
684 if (ret < 0) {
685 goto error;
686 }
687
688 /*
689 * Have we already sent fds to the consumer? If yes, it means
690 * that tracing is started so it is safe to send our updated
691 * stream fds.
692 */
693 if (session->kernel_session->consumer_fds_sent == 1) {
694 ret = send_kconsumer_channel_streams(consumer_data,
695 session->kernel_session->consumer_fd, channel);
696 if (ret < 0) {
697 goto error;
698 }
699 }
700 goto error;
701 }
702 }
703 session_unlock(session);
704 }
705 session_unlock_list();
706 return ret;
707
708 error:
709 session_unlock(session);
710 session_unlock_list();
711 return ret;
712 }
713
714 /*
715 * For each tracing session, update newly registered apps.
716 */
717 static void update_ust_app(int app_sock)
718 {
719 struct ltt_session *sess, *stmp;
720
721 /* For all tracing session(s) */
722 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
723 if (sess->ust_session) {
724 ust_app_global_update(sess->ust_session, app_sock);
725 }
726 }
727 }
728
729 /*
730 * This thread manage event coming from the kernel.
731 *
732 * Features supported in this thread:
733 * -) CPU Hotplug
734 */
735 static void *thread_manage_kernel(void *data)
736 {
737 int ret, i, pollfd, update_poll_flag = 1;
738 uint32_t revents, nb_fd;
739 char tmp;
740 struct lttng_poll_event events;
741
742 DBG("Thread manage kernel started");
743
744 ret = create_thread_poll_set(&events, 2);
745 if (ret < 0) {
746 goto error;
747 }
748
749 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
750 if (ret < 0) {
751 goto error;
752 }
753
754 while (1) {
755 if (update_poll_flag == 1) {
756 /*
757 * Reset number of fd in the poll set. Always 2 since there is the thread
758 * quit pipe and the kernel pipe.
759 */
760 events.nb_fd = 2;
761
762 ret = update_kernel_poll(&events);
763 if (ret < 0) {
764 goto error;
765 }
766 update_poll_flag = 0;
767 }
768
769 nb_fd = LTTNG_POLL_GETNB(&events);
770
771 DBG("Thread kernel polling on %d fds", nb_fd);
772
773 /* Zeroed the poll events */
774 lttng_poll_reset(&events);
775
776 /* Poll infinite value of time */
777 ret = lttng_poll_wait(&events, -1);
778 if (ret < 0) {
779 goto error;
780 } else if (ret == 0) {
781 /* Should not happen since timeout is infinite */
782 ERR("Return value of poll is 0 with an infinite timeout.\n"
783 "This should not have happened! Continuing...");
784 continue;
785 }
786
787 for (i = 0; i < nb_fd; i++) {
788 /* Fetch once the poll data */
789 revents = LTTNG_POLL_GETEV(&events, i);
790 pollfd = LTTNG_POLL_GETFD(&events, i);
791
792 /* Thread quit pipe has been closed. Killing thread. */
793 ret = check_thread_quit_pipe(pollfd, revents);
794 if (ret) {
795 goto error;
796 }
797
798 /* Check for data on kernel pipe */
799 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
800 ret = read(kernel_poll_pipe[0], &tmp, 1);
801 update_poll_flag = 1;
802 continue;
803 } else {
804 /*
805 * New CPU detected by the kernel. Adding kernel stream to
806 * kernel session and updating the kernel consumer
807 */
808 if (revents & LPOLLIN) {
809 ret = update_kernel_stream(&kconsumer_data, pollfd);
810 if (ret < 0) {
811 continue;
812 }
813 break;
814 /*
815 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
816 * and unregister kernel stream at this point.
817 */
818 }
819 }
820 }
821 }
822
823 error:
824 DBG("Kernel thread dying");
825 close(kernel_poll_pipe[0]);
826 close(kernel_poll_pipe[1]);
827
828 lttng_poll_clean(&events);
829
830 return NULL;
831 }
832
833 /*
834 * This thread manage the consumer error sent back to the session daemon.
835 */
836 static void *thread_manage_consumer(void *data)
837 {
838 int sock = 0, i, ret, pollfd;
839 uint32_t revents, nb_fd;
840 enum lttcomm_return_code code;
841 struct lttng_poll_event events;
842 struct consumer_data *consumer_data = data;
843
844 DBG("[thread] Manage consumer started");
845
846 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
847 if (ret < 0) {
848 goto error;
849 }
850
851 /*
852 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
853 * Nothing more will be added to this poll set.
854 */
855 ret = create_thread_poll_set(&events, 2);
856 if (ret < 0) {
857 goto error;
858 }
859
860 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
861 if (ret < 0) {
862 goto error;
863 }
864
865 nb_fd = LTTNG_POLL_GETNB(&events);
866
867 /* Inifinite blocking call, waiting for transmission */
868 ret = lttng_poll_wait(&events, -1);
869 if (ret < 0) {
870 goto error;
871 }
872
873 for (i = 0; i < nb_fd; i++) {
874 /* Fetch once the poll data */
875 revents = LTTNG_POLL_GETEV(&events, i);
876 pollfd = LTTNG_POLL_GETFD(&events, i);
877
878 /* Thread quit pipe has been closed. Killing thread. */
879 ret = check_thread_quit_pipe(pollfd, revents);
880 if (ret) {
881 goto error;
882 }
883
884 /* Event on the registration socket */
885 if (pollfd == consumer_data->err_sock) {
886 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
887 ERR("consumer err socket poll error");
888 goto error;
889 }
890 }
891 }
892
893 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
894 if (sock < 0) {
895 goto error;
896 }
897
898 DBG2("Receiving code from consumer err_sock");
899
900 /* Getting status code from kconsumerd */
901 ret = lttcomm_recv_unix_sock(sock, &code,
902 sizeof(enum lttcomm_return_code));
903 if (ret <= 0) {
904 goto error;
905 }
906
907 if (code == CONSUMERD_COMMAND_SOCK_READY) {
908 consumer_data->cmd_sock =
909 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
910 if (consumer_data->cmd_sock < 0) {
911 sem_post(&consumer_data->sem);
912 PERROR("consumer connect");
913 goto error;
914 }
915 /* Signal condition to tell that the kconsumerd is ready */
916 sem_post(&consumer_data->sem);
917 DBG("consumer command socket ready");
918 } else {
919 ERR("consumer error when waiting for SOCK_READY : %s",
920 lttcomm_get_readable_code(-code));
921 goto error;
922 }
923
924 /* Remove the kconsumerd error sock since we've established a connexion */
925 ret = lttng_poll_del(&events, consumer_data->err_sock);
926 if (ret < 0) {
927 goto error;
928 }
929
930 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
931 if (ret < 0) {
932 goto error;
933 }
934
935 /* Update number of fd */
936 nb_fd = LTTNG_POLL_GETNB(&events);
937
938 /* Inifinite blocking call, waiting for transmission */
939 ret = lttng_poll_wait(&events, -1);
940 if (ret < 0) {
941 goto error;
942 }
943
944 for (i = 0; i < nb_fd; i++) {
945 /* Fetch once the poll data */
946 revents = LTTNG_POLL_GETEV(&events, i);
947 pollfd = LTTNG_POLL_GETFD(&events, i);
948
949 /* Thread quit pipe has been closed. Killing thread. */
950 ret = check_thread_quit_pipe(pollfd, revents);
951 if (ret) {
952 goto error;
953 }
954
955 /* Event on the kconsumerd socket */
956 if (pollfd == sock) {
957 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
958 ERR("consumer err socket second poll error");
959 goto error;
960 }
961 }
962 }
963
964 /* Wait for any kconsumerd error */
965 ret = lttcomm_recv_unix_sock(sock, &code,
966 sizeof(enum lttcomm_return_code));
967 if (ret <= 0) {
968 ERR("consumer closed the command socket");
969 goto error;
970 }
971
972 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
973
974 error:
975 DBG("consumer thread dying");
976 close(consumer_data->err_sock);
977 close(consumer_data->cmd_sock);
978 close(sock);
979
980 unlink(consumer_data->err_unix_sock_path);
981 unlink(consumer_data->cmd_unix_sock_path);
982 consumer_data->pid = 0;
983
984 lttng_poll_clean(&events);
985
986 return NULL;
987 }
988
989 /*
990 * This thread manage application communication.
991 */
992 static void *thread_manage_apps(void *data)
993 {
994 int i, ret, pollfd;
995 uint32_t revents, nb_fd;
996 struct ust_command ust_cmd;
997 struct lttng_poll_event events;
998
999 DBG("[thread] Manage application started");
1000
1001 rcu_register_thread();
1002 rcu_thread_online();
1003
1004 ret = create_thread_poll_set(&events, 2);
1005 if (ret < 0) {
1006 goto error;
1007 }
1008
1009 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1010 if (ret < 0) {
1011 goto error;
1012 }
1013
1014 while (1) {
1015 /* Zeroed the events structure */
1016 lttng_poll_reset(&events);
1017
1018 nb_fd = LTTNG_POLL_GETNB(&events);
1019
1020 DBG("Apps thread polling on %d fds", nb_fd);
1021
1022 /* Inifinite blocking call, waiting for transmission */
1023 ret = lttng_poll_wait(&events, -1);
1024 if (ret < 0) {
1025 goto error;
1026 }
1027
1028 for (i = 0; i < nb_fd; i++) {
1029 /* Fetch once the poll data */
1030 revents = LTTNG_POLL_GETEV(&events, i);
1031 pollfd = LTTNG_POLL_GETFD(&events, i);
1032
1033 /* Thread quit pipe has been closed. Killing thread. */
1034 ret = check_thread_quit_pipe(pollfd, revents);
1035 if (ret) {
1036 goto error;
1037 }
1038
1039 /* Inspect the apps cmd pipe */
1040 if (pollfd == apps_cmd_pipe[0]) {
1041 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1042 ERR("Apps command pipe error");
1043 goto error;
1044 } else if (revents & LPOLLIN) {
1045 /* Empty pipe */
1046 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1047 if (ret < 0 || ret < sizeof(ust_cmd)) {
1048 perror("read apps cmd pipe");
1049 goto error;
1050 }
1051
1052 /* Register applicaton to the session daemon */
1053 ret = ust_app_register(&ust_cmd.reg_msg,
1054 ust_cmd.sock);
1055 if (ret < 0) {
1056 /* Only critical ENOMEM error can be returned here */
1057 goto error;
1058 }
1059
1060 /*
1061 * Add channel(s) and event(s) to newly registered apps
1062 * from lttng global UST domain.
1063 */
1064 update_ust_app(ust_cmd.sock);
1065
1066 ret = ustctl_register_done(ust_cmd.sock);
1067 if (ret < 0) {
1068 /*
1069 * If the registration is not possible, we simply
1070 * unregister the apps and continue
1071 */
1072 ust_app_unregister(ust_cmd.sock);
1073 } else {
1074 /*
1075 * We just need here to monitor the close of the UST
1076 * socket and poll set monitor those by default.
1077 */
1078 ret = lttng_poll_add(&events, ust_cmd.sock, 0);
1079 if (ret < 0) {
1080 goto error;
1081 }
1082
1083 DBG("Apps with sock %d added to poll set",
1084 ust_cmd.sock);
1085 }
1086
1087 break;
1088 }
1089 } else {
1090 /*
1091 * At this point, we know that a registered application made
1092 * the event at poll_wait.
1093 */
1094 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1095 /* Removing from the poll set */
1096 ret = lttng_poll_del(&events, pollfd);
1097 if (ret < 0) {
1098 goto error;
1099 }
1100
1101 /* Socket closed on remote end. */
1102 ust_app_unregister(pollfd);
1103 break;
1104 }
1105 }
1106 }
1107 }
1108
1109 error:
1110 DBG("Application communication apps dying");
1111 close(apps_cmd_pipe[0]);
1112 close(apps_cmd_pipe[1]);
1113
1114 lttng_poll_clean(&events);
1115
1116 rcu_thread_offline();
1117 rcu_unregister_thread();
1118 return NULL;
1119 }
1120
1121 /*
1122 * Dispatch request from the registration threads to the application
1123 * communication thread.
1124 */
1125 static void *thread_dispatch_ust_registration(void *data)
1126 {
1127 int ret;
1128 struct cds_wfq_node *node;
1129 struct ust_command *ust_cmd = NULL;
1130
1131 DBG("[thread] Dispatch UST command started");
1132
1133 while (!dispatch_thread_exit) {
1134 /* Atomically prepare the queue futex */
1135 futex_nto1_prepare(&ust_cmd_queue.futex);
1136
1137 do {
1138 /* Dequeue command for registration */
1139 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1140 if (node == NULL) {
1141 DBG("Woken up but nothing in the UST command queue");
1142 /* Continue thread execution */
1143 break;
1144 }
1145
1146 ust_cmd = caa_container_of(node, struct ust_command, node);
1147
1148 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1149 " gid:%d sock:%d name:%s (version %d.%d)",
1150 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1151 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1152 ust_cmd->sock, ust_cmd->reg_msg.name,
1153 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1154 /*
1155 * Inform apps thread of the new application registration. This
1156 * call is blocking so we can be assured that the data will be read
1157 * at some point in time or wait to the end of the world :)
1158 */
1159 ret = write(apps_cmd_pipe[1], ust_cmd,
1160 sizeof(struct ust_command));
1161 if (ret < 0) {
1162 perror("write apps cmd pipe");
1163 if (errno == EBADF) {
1164 /*
1165 * We can't inform the application thread to process
1166 * registration. We will exit or else application
1167 * registration will not occur and tracing will never
1168 * start.
1169 */
1170 goto error;
1171 }
1172 }
1173 free(ust_cmd);
1174 } while (node != NULL);
1175
1176 /* Futex wait on queue. Blocking call on futex() */
1177 futex_nto1_wait(&ust_cmd_queue.futex);
1178 }
1179
1180 error:
1181 DBG("Dispatch thread dying");
1182 return NULL;
1183 }
1184
1185 /*
1186 * This thread manage application registration.
1187 */
1188 static void *thread_registration_apps(void *data)
1189 {
1190 int sock = 0, i, ret, pollfd;
1191 uint32_t revents, nb_fd;
1192 struct lttng_poll_event events;
1193 /*
1194 * Get allocated in this thread, enqueued to a global queue, dequeued and
1195 * freed in the manage apps thread.
1196 */
1197 struct ust_command *ust_cmd = NULL;
1198
1199 DBG("[thread] Manage application registration started");
1200
1201 ret = lttcomm_listen_unix_sock(apps_sock);
1202 if (ret < 0) {
1203 goto error;
1204 }
1205
1206 /*
1207 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1208 * more will be added to this poll set.
1209 */
1210 ret = create_thread_poll_set(&events, 2);
1211 if (ret < 0) {
1212 goto error;
1213 }
1214
1215 /* Add the application registration socket */
1216 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1217 if (ret < 0) {
1218 goto error;
1219 }
1220
1221 /* Notify all applications to register */
1222 ret = notify_ust_apps(1);
1223 if (ret < 0) {
1224 ERR("Failed to notify applications or create the wait shared memory.\n"
1225 "Execution continues but there might be problem for already\n"
1226 "running applications that wishes to register.");
1227 }
1228
1229 while (1) {
1230 DBG("Accepting application registration");
1231
1232 nb_fd = LTTNG_POLL_GETNB(&events);
1233
1234 /* Inifinite blocking call, waiting for transmission */
1235 ret = lttng_poll_wait(&events, -1);
1236 if (ret < 0) {
1237 goto error;
1238 }
1239
1240 for (i = 0; i < nb_fd; i++) {
1241 /* Fetch once the poll data */
1242 revents = LTTNG_POLL_GETEV(&events, i);
1243 pollfd = LTTNG_POLL_GETFD(&events, i);
1244
1245 /* Thread quit pipe has been closed. Killing thread. */
1246 ret = check_thread_quit_pipe(pollfd, revents);
1247 if (ret) {
1248 goto error;
1249 }
1250
1251 /* Event on the registration socket */
1252 if (pollfd == apps_sock) {
1253 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1254 ERR("Register apps socket poll error");
1255 goto error;
1256 } else if (revents & LPOLLIN) {
1257 sock = lttcomm_accept_unix_sock(apps_sock);
1258 if (sock < 0) {
1259 goto error;
1260 }
1261
1262 /* Create UST registration command for enqueuing */
1263 ust_cmd = malloc(sizeof(struct ust_command));
1264 if (ust_cmd == NULL) {
1265 perror("ust command malloc");
1266 goto error;
1267 }
1268
1269 /*
1270 * Using message-based transmissions to ensure we don't
1271 * have to deal with partially received messages.
1272 */
1273 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1274 sizeof(struct ust_register_msg));
1275 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1276 if (ret < 0) {
1277 perror("lttcomm_recv_unix_sock register apps");
1278 } else {
1279 ERR("Wrong size received on apps register");
1280 }
1281 free(ust_cmd);
1282 close(sock);
1283 continue;
1284 }
1285
1286 ust_cmd->sock = sock;
1287
1288 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1289 " gid:%d sock:%d name:%s (version %d.%d)",
1290 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1291 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1292 ust_cmd->sock, ust_cmd->reg_msg.name,
1293 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1294
1295 /*
1296 * Lock free enqueue the registration request. The red pill
1297 * has been taken! This apps will be part of the *system*.
1298 */
1299 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1300
1301 /*
1302 * Wake the registration queue futex. Implicit memory
1303 * barrier with the exchange in cds_wfq_enqueue.
1304 */
1305 futex_nto1_wake(&ust_cmd_queue.futex);
1306 }
1307 }
1308 }
1309 }
1310
1311 error:
1312 DBG("UST Registration thread dying");
1313
1314 /* Notify that the registration thread is gone */
1315 notify_ust_apps(0);
1316
1317 close(apps_sock);
1318 close(sock);
1319 unlink(apps_unix_sock_path);
1320
1321 lttng_poll_clean(&events);
1322
1323 return NULL;
1324 }
1325
1326 /*
1327 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1328 * exec or it will fails.
1329 */
1330 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1331 {
1332 int ret;
1333 struct timespec timeout;
1334
1335 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1336 timeout.tv_nsec = 0;
1337
1338 /* Setup semaphore */
1339 ret = sem_init(&consumer_data->sem, 0, 0);
1340 if (ret < 0) {
1341 PERROR("sem_init consumer semaphore");
1342 goto error;
1343 }
1344
1345 ret = pthread_create(&consumer_data->thread, NULL,
1346 thread_manage_consumer, consumer_data);
1347 if (ret != 0) {
1348 PERROR("pthread_create consumer");
1349 ret = -1;
1350 goto error;
1351 }
1352
1353 /* Get time for sem_timedwait absolute timeout */
1354 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1355 if (ret < 0) {
1356 PERROR("clock_gettime spawn consumer");
1357 /* Infinite wait for the kconsumerd thread to be ready */
1358 ret = sem_wait(&consumer_data->sem);
1359 } else {
1360 /* Normal timeout if the gettime was successful */
1361 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1362 ret = sem_timedwait(&consumer_data->sem, &timeout);
1363 }
1364
1365 if (ret < 0) {
1366 if (errno == ETIMEDOUT) {
1367 /*
1368 * Call has timed out so we kill the kconsumerd_thread and return
1369 * an error.
1370 */
1371 ERR("The consumer thread was never ready. Killing it");
1372 ret = pthread_cancel(consumer_data->thread);
1373 if (ret < 0) {
1374 PERROR("pthread_cancel consumer thread");
1375 }
1376 } else {
1377 PERROR("semaphore wait failed consumer thread");
1378 }
1379 goto error;
1380 }
1381
1382 pthread_mutex_lock(&consumer_data->pid_mutex);
1383 if (consumer_data->pid == 0) {
1384 ERR("Kconsumerd did not start");
1385 pthread_mutex_unlock(&consumer_data->pid_mutex);
1386 goto error;
1387 }
1388 pthread_mutex_unlock(&consumer_data->pid_mutex);
1389
1390 return 0;
1391
1392 error:
1393 return ret;
1394 }
1395
1396 /*
1397 * Join consumer thread
1398 */
1399 static int join_consumer_thread(struct consumer_data *consumer_data)
1400 {
1401 void *status;
1402 int ret;
1403
1404 if (consumer_data->pid != 0) {
1405 ret = kill(consumer_data->pid, SIGTERM);
1406 if (ret) {
1407 ERR("Error killing consumer daemon");
1408 return ret;
1409 }
1410 return pthread_join(consumer_data->thread, &status);
1411 } else {
1412 return 0;
1413 }
1414 }
1415
1416 /*
1417 * Fork and exec a consumer daemon (consumerd).
1418 *
1419 * Return pid if successful else -1.
1420 */
1421 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1422 {
1423 int ret;
1424 pid_t pid;
1425 const char *verbosity;
1426
1427 DBG("Spawning consumerd");
1428
1429 pid = fork();
1430 if (pid == 0) {
1431 /*
1432 * Exec consumerd.
1433 */
1434 if (opt_verbose > 1 || opt_verbose_consumer) {
1435 verbosity = "--verbose";
1436 } else {
1437 verbosity = "--quiet";
1438 }
1439 switch (consumer_data->type) {
1440 case LTTNG_CONSUMER_KERNEL:
1441 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1442 "lttng-consumerd", verbosity, "-k", NULL);
1443 break;
1444 case LTTNG_CONSUMER_UST:
1445 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1446 "lttng-consumerd", verbosity, "-u", NULL);
1447 break;
1448 default:
1449 perror("unknown consumer type");
1450 exit(EXIT_FAILURE);
1451 }
1452 if (errno != 0) {
1453 perror("kernel start consumer exec");
1454 }
1455 exit(EXIT_FAILURE);
1456 } else if (pid > 0) {
1457 ret = pid;
1458 } else {
1459 perror("start consumer fork");
1460 ret = -errno;
1461 }
1462 return ret;
1463 }
1464
1465 /*
1466 * Spawn the consumerd daemon and session daemon thread.
1467 */
1468 static int start_consumerd(struct consumer_data *consumer_data)
1469 {
1470 int ret;
1471
1472 pthread_mutex_lock(&consumer_data->pid_mutex);
1473 if (consumer_data->pid != 0) {
1474 pthread_mutex_unlock(&consumer_data->pid_mutex);
1475 goto end;
1476 }
1477
1478 ret = spawn_consumerd(consumer_data);
1479 if (ret < 0) {
1480 ERR("Spawning consumerd failed");
1481 pthread_mutex_unlock(&consumer_data->pid_mutex);
1482 goto error;
1483 }
1484
1485 /* Setting up the consumer_data pid */
1486 consumer_data->pid = ret;
1487 DBG2("Consumer pid %d", consumer_data->pid);
1488 pthread_mutex_unlock(&consumer_data->pid_mutex);
1489
1490 DBG2("Spawning consumer control thread");
1491 ret = spawn_consumer_thread(consumer_data);
1492 if (ret < 0) {
1493 ERR("Fatal error spawning consumer control thread");
1494 goto error;
1495 }
1496
1497 end:
1498 return 0;
1499
1500 error:
1501 return ret;
1502 }
1503
1504 /*
1505 * modprobe_kernel_modules
1506 */
1507 static int modprobe_kernel_modules(void)
1508 {
1509 int ret = 0, i;
1510 char modprobe[256];
1511
1512 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1513 ret = snprintf(modprobe, sizeof(modprobe),
1514 "/sbin/modprobe %s%s",
1515 kernel_modules_list[i].required ? "" : "-q ",
1516 kernel_modules_list[i].name);
1517 if (ret < 0) {
1518 perror("snprintf modprobe");
1519 goto error;
1520 }
1521 modprobe[sizeof(modprobe) - 1] = '\0';
1522 ret = system(modprobe);
1523 if (ret == -1) {
1524 ERR("Unable to launch modprobe for module %s",
1525 kernel_modules_list[i].name);
1526 } else if (kernel_modules_list[i].required
1527 && WEXITSTATUS(ret) != 0) {
1528 ERR("Unable to load module %s",
1529 kernel_modules_list[i].name);
1530 } else {
1531 DBG("Modprobe successfully %s",
1532 kernel_modules_list[i].name);
1533 }
1534 }
1535
1536 error:
1537 return ret;
1538 }
1539
1540 /*
1541 * mount_debugfs
1542 */
1543 static int mount_debugfs(char *path)
1544 {
1545 int ret;
1546 char *type = "debugfs";
1547
1548 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1549 if (ret < 0) {
1550 PERROR("Cannot create debugfs path");
1551 goto error;
1552 }
1553
1554 ret = mount(type, path, type, 0, NULL);
1555 if (ret < 0) {
1556 PERROR("Cannot mount debugfs");
1557 goto error;
1558 }
1559
1560 DBG("Mounted debugfs successfully at %s", path);
1561
1562 error:
1563 return ret;
1564 }
1565
1566 /*
1567 * Setup necessary data for kernel tracer action.
1568 */
1569 static void init_kernel_tracer(void)
1570 {
1571 int ret;
1572 char *proc_mounts = "/proc/mounts";
1573 char line[256];
1574 char *debugfs_path = NULL, *lttng_path = NULL;
1575 FILE *fp;
1576
1577 /* Detect debugfs */
1578 fp = fopen(proc_mounts, "r");
1579 if (fp == NULL) {
1580 ERR("Unable to probe %s", proc_mounts);
1581 goto error;
1582 }
1583
1584 while (fgets(line, sizeof(line), fp) != NULL) {
1585 if (strstr(line, "debugfs") != NULL) {
1586 /* Remove first string */
1587 strtok(line, " ");
1588 /* Dup string here so we can reuse line later on */
1589 debugfs_path = strdup(strtok(NULL, " "));
1590 DBG("Got debugfs path : %s", debugfs_path);
1591 break;
1592 }
1593 }
1594
1595 fclose(fp);
1596
1597 /* Mount debugfs if needded */
1598 if (debugfs_path == NULL) {
1599 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1600 if (ret < 0) {
1601 perror("asprintf debugfs path");
1602 goto error;
1603 }
1604 ret = mount_debugfs(debugfs_path);
1605 if (ret < 0) {
1606 perror("Cannot mount debugfs");
1607 goto error;
1608 }
1609 }
1610
1611 /* Modprobe lttng kernel modules */
1612 ret = modprobe_kernel_modules();
1613 if (ret < 0) {
1614 goto error;
1615 }
1616
1617 /* Setup lttng kernel path */
1618 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1619 if (ret < 0) {
1620 perror("asprintf lttng path");
1621 goto error;
1622 }
1623
1624 /* Open debugfs lttng */
1625 kernel_tracer_fd = open(lttng_path, O_RDWR);
1626 if (kernel_tracer_fd < 0) {
1627 DBG("Failed to open %s", lttng_path);
1628 goto error;
1629 }
1630
1631 free(lttng_path);
1632 free(debugfs_path);
1633 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1634 return;
1635
1636 error:
1637 if (lttng_path) {
1638 free(lttng_path);
1639 }
1640 if (debugfs_path) {
1641 free(debugfs_path);
1642 }
1643 WARN("No kernel tracer available");
1644 kernel_tracer_fd = 0;
1645 return;
1646 }
1647
1648 /*
1649 * Init tracing by creating trace directory and sending fds kernel consumer.
1650 */
1651 static int init_kernel_tracing(struct ltt_kernel_session *session)
1652 {
1653 int ret = 0;
1654
1655 if (session->consumer_fds_sent == 0) {
1656 /*
1657 * Assign default kernel consumer socket if no consumer assigned to the
1658 * kernel session. At this point, it's NOT suppose to be 0 but this is
1659 * an extra security check.
1660 */
1661 if (session->consumer_fd == 0) {
1662 session->consumer_fd = kconsumer_data.cmd_sock;
1663 }
1664
1665 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1666 if (ret < 0) {
1667 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1668 goto error;
1669 }
1670
1671 session->consumer_fds_sent = 1;
1672 }
1673
1674 error:
1675 return ret;
1676 }
1677
1678 /*
1679 * Create an UST session and add it to the session ust list.
1680 */
1681 static int create_ust_session(struct ltt_session *session,
1682 struct lttng_domain *domain)
1683 {
1684 int ret;
1685 unsigned int uid;
1686 struct ltt_ust_session *lus = NULL;
1687
1688 switch (domain->type) {
1689 case LTTNG_DOMAIN_UST:
1690 break;
1691 default:
1692 ret = LTTCOMM_UNKNOWN_DOMAIN;
1693 goto error;
1694 }
1695
1696 DBG("Creating UST session");
1697
1698 session_lock_list();
1699 uid = session_list_ptr->count;
1700 session_unlock_list();
1701
1702 lus = trace_ust_create_session(session->path, uid, domain);
1703 if (lus == NULL) {
1704 ret = LTTCOMM_UST_SESS_FAIL;
1705 goto error;
1706 }
1707
1708 ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1709 geteuid(), allowed_group());
1710 if (ret < 0) {
1711 if (ret != -EEXIST) {
1712 ERR("Trace directory creation error");
1713 ret = LTTCOMM_UST_SESS_FAIL;
1714 goto error;
1715 }
1716 }
1717
1718 /* The domain type dictate different actions on session creation */
1719 switch (domain->type) {
1720 case LTTNG_DOMAIN_UST:
1721 /* No ustctl for the global UST domain */
1722 break;
1723 default:
1724 ERR("Unknown UST domain on create session %d", domain->type);
1725 goto error;
1726 }
1727 session->ust_session = lus;
1728
1729 return LTTCOMM_OK;
1730
1731 error:
1732 free(lus);
1733 return ret;
1734 }
1735
1736 /*
1737 * Create a kernel tracer session then create the default channel.
1738 */
1739 static int create_kernel_session(struct ltt_session *session)
1740 {
1741 int ret;
1742
1743 DBG("Creating kernel session");
1744
1745 ret = kernel_create_session(session, kernel_tracer_fd);
1746 if (ret < 0) {
1747 ret = LTTCOMM_KERN_SESS_FAIL;
1748 goto error;
1749 }
1750
1751 /* Set kernel consumer socket fd */
1752 if (kconsumer_data.cmd_sock) {
1753 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1754 }
1755
1756 ret = mkdir_recursive(session->kernel_session->trace_path,
1757 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1758 if (ret < 0) {
1759 if (ret != -EEXIST) {
1760 ERR("Trace directory creation error");
1761 goto error;
1762 }
1763 }
1764
1765 error:
1766 return ret;
1767 }
1768
1769 /*
1770 * Using the session list, filled a lttng_session array to send back to the
1771 * client for session listing.
1772 *
1773 * The session list lock MUST be acquired before calling this function. Use
1774 * session_lock_list() and session_unlock_list().
1775 */
1776 static void list_lttng_sessions(struct lttng_session *sessions)
1777 {
1778 int i = 0;
1779 struct ltt_session *session;
1780
1781 DBG("Getting all available session");
1782 /*
1783 * Iterate over session list and append data after the control struct in
1784 * the buffer.
1785 */
1786 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1787 strncpy(sessions[i].path, session->path, PATH_MAX);
1788 sessions[i].path[PATH_MAX - 1] = '\0';
1789 strncpy(sessions[i].name, session->name, NAME_MAX);
1790 sessions[i].name[NAME_MAX - 1] = '\0';
1791 i++;
1792 }
1793 }
1794
1795 /*
1796 * Fill lttng_channel array of all channels.
1797 */
1798 static void list_lttng_channels(int domain, struct ltt_session *session,
1799 struct lttng_channel *channels)
1800 {
1801 int i = 0;
1802 struct ltt_kernel_channel *kchan;
1803
1804 DBG("Listing channels for session %s", session->name);
1805
1806 switch (domain) {
1807 case LTTNG_DOMAIN_KERNEL:
1808 /* Kernel channels */
1809 if (session->kernel_session != NULL) {
1810 cds_list_for_each_entry(kchan,
1811 &session->kernel_session->channel_list.head, list) {
1812 /* Copy lttng_channel struct to array */
1813 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1814 channels[i].enabled = kchan->enabled;
1815 i++;
1816 }
1817 }
1818 break;
1819 case LTTNG_DOMAIN_UST:
1820 {
1821 struct cds_lfht_iter iter;
1822 struct ltt_ust_channel *uchan;
1823
1824 cds_lfht_for_each_entry(session->ust_session->domain_global.channels,
1825 &iter, uchan, node) {
1826 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
1827 channels[i].attr.overwrite = uchan->attr.overwrite;
1828 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
1829 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
1830 channels[i].attr.switch_timer_interval =
1831 uchan->attr.switch_timer_interval;
1832 channels[i].attr.read_timer_interval =
1833 uchan->attr.read_timer_interval;
1834 channels[i].attr.output = uchan->attr.output;
1835 }
1836 break;
1837 }
1838 default:
1839 break;
1840 }
1841 }
1842
1843 /*
1844 * Create a list of ust global domain events.
1845 */
1846 static int list_lttng_ust_global_events(char *channel_name,
1847 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
1848 {
1849 int i = 0, ret = 0;
1850 unsigned int nb_event = 0;
1851 struct cds_lfht_iter iter;
1852 struct ltt_ust_channel *uchan;
1853 struct ltt_ust_event *uevent;
1854 struct lttng_event *tmp;
1855
1856 DBG("Listing UST global events for channel %s", channel_name);
1857
1858 rcu_read_lock();
1859
1860 /* Count events in all channels */
1861 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1862 nb_event += hashtable_get_count(uchan->events);
1863 }
1864
1865 if (nb_event == 0) {
1866 ret = nb_event;
1867 goto error;
1868 }
1869
1870 DBG3("Listing UST global %d events", nb_event);
1871
1872 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
1873 if (tmp == NULL) {
1874 ret = -LTTCOMM_FATAL;
1875 goto error;
1876 }
1877
1878 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1879 cds_lfht_for_each_entry(uchan->events, &iter, uevent, node) {
1880 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
1881 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1882 switch (uevent->attr.instrumentation) {
1883 case LTTNG_UST_TRACEPOINT:
1884 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
1885 break;
1886 case LTTNG_UST_PROBE:
1887 tmp[i].type = LTTNG_EVENT_PROBE;
1888 break;
1889 case LTTNG_UST_FUNCTION:
1890 tmp[i].type = LTTNG_EVENT_FUNCTION;
1891 break;
1892 }
1893 i++;
1894 }
1895 }
1896
1897 ret = nb_event;
1898 *events = tmp;
1899
1900 error:
1901 rcu_read_unlock();
1902 return ret;
1903 }
1904
1905 /*
1906 * Fill lttng_event array of all kernel events in the channel.
1907 */
1908 static int list_lttng_kernel_events(char *channel_name,
1909 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
1910 {
1911 int i = 0, ret;
1912 unsigned int nb_event;
1913 struct ltt_kernel_event *event;
1914 struct ltt_kernel_channel *kchan;
1915
1916 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
1917 if (kchan == NULL) {
1918 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1919 goto error;
1920 }
1921
1922 nb_event = kchan->event_count;
1923
1924 DBG("Listing events for channel %s", kchan->channel->name);
1925
1926 if (nb_event == 0) {
1927 ret = nb_event;
1928 goto error;
1929 }
1930
1931 *events = zmalloc(nb_event * sizeof(struct lttng_event));
1932 if (*events == NULL) {
1933 ret = LTTCOMM_FATAL;
1934 goto error;
1935 }
1936
1937 /* Kernel channels */
1938 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1939 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1940 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1941 (*events)[i].enabled = event->enabled;
1942 switch (event->event->instrumentation) {
1943 case LTTNG_KERNEL_TRACEPOINT:
1944 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
1945 break;
1946 case LTTNG_KERNEL_KPROBE:
1947 case LTTNG_KERNEL_KRETPROBE:
1948 (*events)[i].type = LTTNG_EVENT_PROBE;
1949 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
1950 sizeof(struct lttng_kernel_kprobe));
1951 break;
1952 case LTTNG_KERNEL_FUNCTION:
1953 (*events)[i].type = LTTNG_EVENT_FUNCTION;
1954 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
1955 sizeof(struct lttng_kernel_function));
1956 break;
1957 case LTTNG_KERNEL_NOOP:
1958 (*events)[i].type = LTTNG_EVENT_NOOP;
1959 break;
1960 case LTTNG_KERNEL_SYSCALL:
1961 (*events)[i].type = LTTNG_EVENT_SYSCALL;
1962 break;
1963 case LTTNG_KERNEL_ALL:
1964 assert(0);
1965 break;
1966 }
1967 i++;
1968 }
1969
1970 return nb_event;
1971
1972 error:
1973 return ret;
1974 }
1975
1976 /*
1977 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1978 */
1979 static int cmd_disable_channel(struct ltt_session *session,
1980 int domain, char *channel_name)
1981 {
1982 int ret;
1983
1984 switch (domain) {
1985 case LTTNG_DOMAIN_KERNEL:
1986 ret = channel_kernel_disable(session->kernel_session,
1987 channel_name);
1988 if (ret != LTTCOMM_OK) {
1989 goto error;
1990 }
1991
1992 kernel_wait_quiescent(kernel_tracer_fd);
1993 break;
1994 case LTTNG_DOMAIN_UST_PID:
1995 break;
1996 default:
1997 ret = LTTCOMM_UNKNOWN_DOMAIN;
1998 goto error;
1999 }
2000
2001 ret = LTTCOMM_OK;
2002
2003 error:
2004 return ret;
2005 }
2006
2007 /*
2008 * Copy channel from attributes and set it in the application channel list.
2009 */
2010 /*
2011 static int copy_ust_channel_to_app(struct ltt_ust_session *usess,
2012 struct lttng_channel *attr, struct ust_app *app)
2013 {
2014 int ret;
2015 struct ltt_ust_channel *uchan, *new_chan;
2016
2017 uchan = trace_ust_get_channel_by_key(usess->channels, attr->name);
2018 if (uchan == NULL) {
2019 ret = LTTCOMM_FATAL;
2020 goto error;
2021 }
2022
2023 new_chan = trace_ust_create_channel(attr, usess->path);
2024 if (new_chan == NULL) {
2025 PERROR("malloc ltt_ust_channel");
2026 ret = LTTCOMM_FATAL;
2027 goto error;
2028 }
2029
2030 ret = channel_ust_copy(new_chan, uchan);
2031 if (ret < 0) {
2032 ret = LTTCOMM_FATAL;
2033 goto error;
2034 }
2035
2036 error:
2037 return ret;
2038 }
2039 */
2040
2041 /*
2042 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2043 */
2044 static int cmd_enable_channel(struct ltt_session *session,
2045 struct lttng_domain *domain, struct lttng_channel *attr)
2046 {
2047 int ret;
2048 struct ltt_ust_session *usess = session->ust_session;
2049
2050 DBG("Enabling channel %s for session %s", attr->name, session->name);
2051
2052 switch (domain->type) {
2053 case LTTNG_DOMAIN_KERNEL:
2054 {
2055 struct ltt_kernel_channel *kchan;
2056
2057 kchan = trace_kernel_get_channel_by_name(attr->name,
2058 session->kernel_session);
2059 if (kchan == NULL) {
2060 ret = channel_kernel_create(session->kernel_session,
2061 attr, kernel_poll_pipe[1]);
2062 } else {
2063 ret = channel_kernel_enable(session->kernel_session, kchan);
2064 }
2065
2066 if (ret != LTTCOMM_OK) {
2067 goto error;
2068 }
2069
2070 kernel_wait_quiescent(kernel_tracer_fd);
2071 break;
2072 }
2073 case LTTNG_DOMAIN_UST:
2074 {
2075 struct ltt_ust_channel *uchan;
2076
2077 DBG2("Enabling channel for LTTNG_DOMAIN_UST");
2078
2079 /* Get channel in global UST domain HT */
2080 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2081 attr->name);
2082 if (uchan == NULL) {
2083 uchan = trace_ust_create_channel(attr, usess->pathname);
2084 if (uchan == NULL) {
2085 ret = LTTCOMM_UST_CHAN_FAIL;
2086 goto error;
2087 }
2088
2089 rcu_read_lock();
2090 hashtable_add_unique(usess->domain_global.channels, &uchan->node);
2091 rcu_read_unlock();
2092 DBG2("UST channel %s added to global domain HT", attr->name);
2093 } else {
2094 ret = LTTCOMM_UST_CHAN_EXIST;
2095 goto error;
2096 }
2097
2098 /* Add channel to all registered applications */
2099 ret = ust_app_add_channel_all(usess, uchan);
2100 if (ret != 0) {
2101 goto error;
2102 }
2103
2104 break;
2105 }
2106 case LTTNG_DOMAIN_UST_PID:
2107 {
2108 /*
2109 int sock;
2110 struct ltt_ust_channel *uchan;
2111 struct ltt_ust_session *usess;
2112 struct ust_app *app;
2113
2114 usess = trace_ust_get_session_by_pid(&session->ust_session_list,
2115 domain->attr.pid);
2116 if (usess == NULL) {
2117 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2118 goto error;
2119 }
2120
2121 app = ust_app_get_by_pid(domain->attr.pid);
2122 if (app == NULL) {
2123 ret = LTTCOMM_APP_NOT_FOUND;
2124 goto error;
2125 }
2126 sock = app->sock;
2127
2128 uchan = trace_ust_get_channel_by_name(attr->name, usess);
2129 if (uchan == NULL) {
2130 ret = channel_ust_create(usess, attr, sock);
2131 } else {
2132 ret = channel_ust_enable(usess, uchan, sock);
2133 }
2134
2135 if (ret != LTTCOMM_OK) {
2136 goto error;
2137 }
2138
2139 ret = copy_ust_channel_to_app(usess, attr, app);
2140 if (ret != LTTCOMM_OK) {
2141 goto error;
2142 }
2143
2144 DBG("UST channel %s created for app sock %d with pid %d",
2145 attr->name, app->sock, domain->attr.pid);
2146 */
2147 ret = LTTCOMM_NOT_IMPLEMENTED;
2148 goto error;
2149 }
2150 default:
2151 ret = LTTCOMM_UNKNOWN_DOMAIN;
2152 goto error;
2153 }
2154
2155 ret = LTTCOMM_OK;
2156
2157 error:
2158 return ret;
2159 }
2160
2161 /*
2162 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2163 */
2164 static int cmd_disable_event(struct ltt_session *session, int domain,
2165 char *channel_name, char *event_name)
2166 {
2167 int ret;
2168
2169 switch (domain) {
2170 case LTTNG_DOMAIN_KERNEL:
2171 {
2172 struct ltt_kernel_channel *kchan;
2173
2174 kchan = trace_kernel_get_channel_by_name(channel_name,
2175 session->kernel_session);
2176 if (kchan == NULL) {
2177 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2178 goto error;
2179 }
2180
2181 ret = event_kernel_disable_tracepoint(session->kernel_session, kchan, event_name);
2182 if (ret != LTTCOMM_OK) {
2183 goto error;
2184 }
2185
2186 kernel_wait_quiescent(kernel_tracer_fd);
2187 break;
2188 }
2189 case LTTNG_DOMAIN_UST:
2190 case LTTNG_DOMAIN_UST_EXEC_NAME:
2191 case LTTNG_DOMAIN_UST_PID:
2192 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2193 default:
2194 /* TODO: Other UST domains */
2195 ret = LTTCOMM_NOT_IMPLEMENTED;
2196 goto error;
2197 }
2198
2199 ret = LTTCOMM_OK;
2200
2201 error:
2202 return ret;
2203 }
2204
2205 /*
2206 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2207 */
2208 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2209 char *channel_name)
2210 {
2211 int ret;
2212 struct ltt_kernel_channel *kchan;
2213
2214 switch (domain) {
2215 case LTTNG_DOMAIN_KERNEL:
2216 kchan = trace_kernel_get_channel_by_name(channel_name,
2217 session->kernel_session);
2218 if (kchan == NULL) {
2219 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2220 goto error;
2221 }
2222
2223 ret = event_kernel_disable_all(session->kernel_session, kchan);
2224 if (ret != LTTCOMM_OK) {
2225 goto error;
2226 }
2227
2228 kernel_wait_quiescent(kernel_tracer_fd);
2229 break;
2230 default:
2231 /* TODO: Userspace tracing */
2232 ret = LTTCOMM_NOT_IMPLEMENTED;
2233 goto error;
2234 }
2235
2236 ret = LTTCOMM_OK;
2237
2238 error:
2239 return ret;
2240 }
2241
2242 /*
2243 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2244 */
2245 static int cmd_add_context(struct ltt_session *session, int domain,
2246 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2247 {
2248 int ret;
2249
2250 switch (domain) {
2251 case LTTNG_DOMAIN_KERNEL:
2252 /* Add kernel context to kernel tracer */
2253 ret = context_kernel_add(session->kernel_session, ctx,
2254 event_name, channel_name);
2255 if (ret != LTTCOMM_OK) {
2256 goto error;
2257 }
2258 break;
2259 case LTTNG_DOMAIN_UST:
2260 {
2261 /*
2262 struct ltt_ust_session *usess;
2263
2264 cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2265 ret = context_ust_add(usess, ctx,
2266 event_name, channel_name, domain);
2267 if (ret != LTTCOMM_OK) {
2268 goto error;
2269 }
2270 }
2271 break;
2272 */
2273 }
2274 default:
2275 /* TODO: UST other domains */
2276 ret = LTTCOMM_NOT_IMPLEMENTED;
2277 goto error;
2278 }
2279
2280 ret = LTTCOMM_OK;
2281
2282 error:
2283 return ret;
2284 }
2285
2286 /*
2287 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2288 */
2289 static int cmd_enable_event(struct ltt_session *session, int domain,
2290 char *channel_name, struct lttng_event *event)
2291 {
2292 int ret;
2293 struct lttng_channel *attr;
2294 struct ltt_ust_session *usess = session->ust_session;
2295
2296 switch (domain) {
2297 case LTTNG_DOMAIN_KERNEL:
2298 {
2299 struct ltt_kernel_channel *kchan;
2300
2301 kchan = trace_kernel_get_channel_by_name(channel_name,
2302 session->kernel_session);
2303 if (kchan == NULL) {
2304 attr = channel_new_default_attr(domain);
2305 if (attr == NULL) {
2306 ret = LTTCOMM_FATAL;
2307 goto error;
2308 }
2309 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2310
2311 /* This call will notify the kernel thread */
2312 ret = channel_kernel_create(session->kernel_session,
2313 attr, kernel_poll_pipe[1]);
2314 if (ret != LTTCOMM_OK) {
2315 goto error;
2316 }
2317 }
2318
2319 /* Get the newly created kernel channel pointer */
2320 kchan = trace_kernel_get_channel_by_name(channel_name,
2321 session->kernel_session);
2322 if (kchan == NULL) {
2323 /* This sould not happen... */
2324 ret = LTTCOMM_FATAL;
2325 goto error;
2326 }
2327
2328 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2329 event);
2330 if (ret != LTTCOMM_OK) {
2331 goto error;
2332 }
2333
2334 kernel_wait_quiescent(kernel_tracer_fd);
2335 break;
2336 }
2337 case LTTNG_DOMAIN_UST:
2338 {
2339 struct ltt_ust_channel *uchan;
2340 struct ltt_ust_event *uevent;
2341
2342 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2343 channel_name);
2344 if (uchan == NULL) {
2345 /* TODO: Create default channel */
2346 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2347 goto error;
2348 }
2349
2350 uevent = trace_ust_find_event_by_name(uchan->events, event->name);
2351 if (uevent == NULL) {
2352 uevent = trace_ust_create_event(event);
2353 if (uevent == NULL) {
2354 ret = LTTCOMM_FATAL;
2355 goto error;
2356 }
2357
2358 }
2359
2360 ret = ust_app_add_event_all(usess, uchan, uevent);
2361 if (ret < 0) {
2362 ret = LTTCOMM_UST_ENABLE_FAIL;
2363 goto error;
2364 }
2365
2366 /* Add ltt ust event to channel */
2367 rcu_read_lock();
2368 hashtable_add_unique(uchan->events, &uevent->node);
2369 rcu_read_unlock();
2370
2371 DBG3("UST ltt event %s added to channel %s", uevent->attr.name,
2372 uchan->name);
2373 break;
2374 }
2375 case LTTNG_DOMAIN_UST_EXEC_NAME:
2376 case LTTNG_DOMAIN_UST_PID:
2377 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2378 default:
2379 ret = LTTCOMM_NOT_IMPLEMENTED;
2380 goto error;
2381 }
2382
2383 ret = LTTCOMM_OK;
2384
2385 error:
2386 return ret;
2387 }
2388
2389 /*
2390 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2391 */
2392 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2393 char *channel_name, int event_type)
2394 {
2395 int ret;
2396 struct ltt_kernel_channel *kchan;
2397
2398 switch (domain) {
2399 case LTTNG_DOMAIN_KERNEL:
2400 kchan = trace_kernel_get_channel_by_name(channel_name,
2401 session->kernel_session);
2402 if (kchan == NULL) {
2403 /* This call will notify the kernel thread */
2404 ret = channel_kernel_create(session->kernel_session, NULL,
2405 kernel_poll_pipe[1]);
2406 if (ret != LTTCOMM_OK) {
2407 goto error;
2408 }
2409 }
2410
2411 /* Get the newly created kernel channel pointer */
2412 kchan = trace_kernel_get_channel_by_name(channel_name,
2413 session->kernel_session);
2414 if (kchan == NULL) {
2415 /* This sould not happen... */
2416 ret = LTTCOMM_FATAL;
2417 goto error;
2418 }
2419
2420 switch (event_type) {
2421 case LTTNG_KERNEL_SYSCALL:
2422 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2423 kchan, kernel_tracer_fd);
2424 break;
2425 case LTTNG_KERNEL_TRACEPOINT:
2426 /*
2427 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2428 * events already registered to the channel.
2429 */
2430 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2431 kchan, kernel_tracer_fd);
2432 break;
2433 case LTTNG_KERNEL_ALL:
2434 /* Enable syscalls and tracepoints */
2435 ret = event_kernel_enable_all(session->kernel_session,
2436 kchan, kernel_tracer_fd);
2437 break;
2438 default:
2439 ret = LTTCOMM_KERN_ENABLE_FAIL;
2440 goto error;
2441 }
2442 if (ret != LTTCOMM_OK) {
2443 goto error;
2444 }
2445
2446 kernel_wait_quiescent(kernel_tracer_fd);
2447 break;
2448 default:
2449 /* TODO: Userspace tracing */
2450 ret = LTTCOMM_NOT_IMPLEMENTED;
2451 goto error;
2452 }
2453
2454 ret = LTTCOMM_OK;
2455
2456 error:
2457 return ret;
2458 }
2459
2460 /*
2461 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2462 */
2463 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2464 {
2465 int ret;
2466 ssize_t nb_events = 0;
2467
2468 switch (domain) {
2469 case LTTNG_DOMAIN_KERNEL:
2470 nb_events = kernel_list_events(kernel_tracer_fd, events);
2471 if (nb_events < 0) {
2472 ret = LTTCOMM_KERN_LIST_FAIL;
2473 goto error;
2474 }
2475 break;
2476 case LTTNG_DOMAIN_UST:
2477 nb_events = ust_app_list_events(events);
2478 if (nb_events < 0) {
2479 ret = LTTCOMM_UST_LIST_FAIL;
2480 goto error;
2481 }
2482 break;
2483 default:
2484 ret = LTTCOMM_NOT_IMPLEMENTED;
2485 goto error;
2486 }
2487
2488 return nb_events;
2489
2490 error:
2491 /* Return negative value to differentiate return code */
2492 return -ret;
2493 }
2494
2495 /*
2496 * Command LTTNG_START_TRACE processed by the client thread.
2497 */
2498 static int cmd_start_trace(struct ltt_session *session)
2499 {
2500 int ret;
2501 struct ltt_kernel_session *ksession;
2502 struct ltt_ust_session *usess;
2503
2504 /* Short cut */
2505 ksession = session->kernel_session;
2506 usess = session->ust_session;
2507
2508 /* Kernel tracing */
2509 if (ksession != NULL) {
2510 struct ltt_kernel_channel *kchan;
2511
2512 /* Open kernel metadata */
2513 if (ksession->metadata == NULL) {
2514 ret = kernel_open_metadata(ksession, ksession->trace_path);
2515 if (ret < 0) {
2516 ret = LTTCOMM_KERN_META_FAIL;
2517 goto error;
2518 }
2519 }
2520
2521 /* Open kernel metadata stream */
2522 if (ksession->metadata_stream_fd == 0) {
2523 ret = kernel_open_metadata_stream(ksession);
2524 if (ret < 0) {
2525 ERR("Kernel create metadata stream failed");
2526 ret = LTTCOMM_KERN_STREAM_FAIL;
2527 goto error;
2528 }
2529 }
2530
2531 /* For each channel */
2532 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2533 if (kchan->stream_count == 0) {
2534 ret = kernel_open_channel_stream(kchan);
2535 if (ret < 0) {
2536 ret = LTTCOMM_KERN_STREAM_FAIL;
2537 goto error;
2538 }
2539 /* Update the stream global counter */
2540 ksession->stream_count_global += ret;
2541 }
2542 }
2543
2544 /* Setup kernel consumer socket and send fds to it */
2545 ret = init_kernel_tracing(ksession);
2546 if (ret < 0) {
2547 ret = LTTCOMM_KERN_START_FAIL;
2548 goto error;
2549 }
2550
2551 /* This start the kernel tracing */
2552 ret = kernel_start_session(ksession);
2553 if (ret < 0) {
2554 ret = LTTCOMM_KERN_START_FAIL;
2555 goto error;
2556 }
2557
2558 /* Quiescent wait after starting trace */
2559 kernel_wait_quiescent(kernel_tracer_fd);
2560 }
2561
2562 /* Flag session that trace should start automatically */
2563 if (usess) {
2564 usess->start_trace = 1;
2565
2566 ret = ust_app_start_trace_all(usess);
2567 if (ret < 0) {
2568 ret = LTTCOMM_UST_START_FAIL;
2569 goto error;
2570 }
2571 }
2572
2573 ret = LTTCOMM_OK;
2574
2575 error:
2576 return ret;
2577 }
2578
2579 /*
2580 * Command LTTNG_STOP_TRACE processed by the client thread.
2581 */
2582 static int cmd_stop_trace(struct ltt_session *session)
2583 {
2584 int ret;
2585 struct ltt_kernel_channel *kchan;
2586 struct ltt_kernel_session *ksession;
2587 //struct ltt_ust_session *usess;
2588 //struct ltt_ust_channel *ustchan;
2589
2590 /* Short cut */
2591 ksession = session->kernel_session;
2592
2593 /* Kernel tracer */
2594 if (ksession != NULL) {
2595 DBG("Stop kernel tracing");
2596
2597 /* Flush all buffers before stopping */
2598 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2599 if (ret < 0) {
2600 ERR("Kernel metadata flush failed");
2601 }
2602
2603 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2604 ret = kernel_flush_buffer(kchan);
2605 if (ret < 0) {
2606 ERR("Kernel flush buffer error");
2607 }
2608 }
2609
2610 ret = kernel_stop_session(ksession);
2611 if (ret < 0) {
2612 ret = LTTCOMM_KERN_STOP_FAIL;
2613 goto error;
2614 }
2615
2616 kernel_wait_quiescent(kernel_tracer_fd);
2617 }
2618
2619 #ifdef DISABLE
2620 /* Stop each UST session */
2621 DBG("Stop UST tracing");
2622 cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2623 /* Flush all buffers before stopping */
2624 ret = ustctl_flush_buffer(usess->sock, usess->metadata->obj);
2625 if (ret < 0) {
2626 ERR("UST metadata flush failed");
2627 }
2628
2629 cds_list_for_each_entry(ustchan, &usess->channels.head, list) {
2630 ret = ustctl_flush_buffer(usess->sock, ustchan->obj);
2631 if (ret < 0) {
2632 ERR("UST flush buffer error");
2633 }
2634 }
2635
2636 ret = ustctl_stop_session(usess->sock, usess->handle);
2637 if (ret < 0) {
2638 ret = LTTCOMM_KERN_STOP_FAIL;
2639 goto error;
2640 }
2641
2642 ustctl_wait_quiescent(usess->sock);
2643 }
2644 #endif
2645
2646 ret = LTTCOMM_OK;
2647
2648 error:
2649 return ret;
2650 }
2651
2652 /*
2653 * Command LTTNG_CREATE_SESSION processed by the client thread.
2654 */
2655 static int cmd_create_session(char *name, char *path)
2656 {
2657 int ret;
2658
2659 ret = session_create(name, path);
2660 if (ret != LTTCOMM_OK) {
2661 goto error;
2662 }
2663
2664 ret = LTTCOMM_OK;
2665
2666 error:
2667 return ret;
2668 }
2669
2670 /*
2671 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2672 */
2673 static int cmd_destroy_session(struct ltt_session *session, char *name)
2674 {
2675 int ret;
2676
2677 /* Clean kernel session teardown */
2678 teardown_kernel_session(session);
2679
2680 /*
2681 * Must notify the kernel thread here to update it's poll setin order
2682 * to remove the channel(s)' fd just destroyed.
2683 */
2684 ret = notify_thread_pipe(kernel_poll_pipe[1]);
2685 if (ret < 0) {
2686 perror("write kernel poll pipe");
2687 }
2688
2689 ret = session_destroy(session);
2690
2691 return ret;
2692 }
2693
2694 /*
2695 * Command LTTNG_CALIBRATE processed by the client thread.
2696 */
2697 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2698 {
2699 int ret;
2700
2701 switch (domain) {
2702 case LTTNG_DOMAIN_KERNEL:
2703 {
2704 struct lttng_kernel_calibrate kcalibrate;
2705
2706 kcalibrate.type = calibrate->type;
2707 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2708 if (ret < 0) {
2709 ret = LTTCOMM_KERN_ENABLE_FAIL;
2710 goto error;
2711 }
2712 break;
2713 }
2714 default:
2715 /* TODO: Userspace tracing */
2716 ret = LTTCOMM_NOT_IMPLEMENTED;
2717 goto error;
2718 }
2719
2720 ret = LTTCOMM_OK;
2721
2722 error:
2723 return ret;
2724 }
2725
2726 /*
2727 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2728 */
2729 static int cmd_register_consumer(struct ltt_session *session, int domain,
2730 char *sock_path)
2731 {
2732 int ret, sock;
2733
2734 switch (domain) {
2735 case LTTNG_DOMAIN_KERNEL:
2736 /* Can't register a consumer if there is already one */
2737 if (session->kernel_session->consumer_fd != 0) {
2738 ret = LTTCOMM_KERN_CONSUMER_FAIL;
2739 goto error;
2740 }
2741
2742 sock = lttcomm_connect_unix_sock(sock_path);
2743 if (sock < 0) {
2744 ret = LTTCOMM_CONNECT_FAIL;
2745 goto error;
2746 }
2747
2748 session->kernel_session->consumer_fd = sock;
2749 break;
2750 default:
2751 /* TODO: Userspace tracing */
2752 ret = LTTCOMM_NOT_IMPLEMENTED;
2753 goto error;
2754 }
2755
2756 ret = LTTCOMM_OK;
2757
2758 error:
2759 return ret;
2760 }
2761
2762 /*
2763 * Command LTTNG_LIST_DOMAINS processed by the client thread.
2764 */
2765 static ssize_t cmd_list_domains(struct ltt_session *session,
2766 struct lttng_domain **domains)
2767 {
2768 int ret, index = 0;
2769 ssize_t nb_dom = 0;
2770
2771 if (session->kernel_session != NULL) {
2772 DBG3("Listing domains found kernel domain");
2773 nb_dom++;
2774 }
2775
2776 if (session->ust_session != NULL) {
2777 DBG3("Listing domains found UST global domain");
2778 nb_dom++;
2779 }
2780
2781 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
2782 if (*domains == NULL) {
2783 ret = -LTTCOMM_FATAL;
2784 goto error;
2785 }
2786
2787 if (session->kernel_session != NULL) {
2788 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
2789 index++;
2790 }
2791
2792 if (session->ust_session != NULL) {
2793 (*domains)[index].type = LTTNG_DOMAIN_UST;
2794 index++;
2795 }
2796
2797 return nb_dom;
2798
2799 error:
2800 return ret;
2801 }
2802
2803 /*
2804 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2805 */
2806 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2807 struct lttng_channel **channels)
2808 {
2809 int ret;
2810 ssize_t nb_chan = 0;
2811
2812 switch (domain) {
2813 case LTTNG_DOMAIN_KERNEL:
2814 if (session->kernel_session != NULL) {
2815 nb_chan = session->kernel_session->channel_count;
2816 }
2817 DBG3("Number of kernel channels %ld", nb_chan);
2818 break;
2819 case LTTNG_DOMAIN_UST:
2820 if (session->ust_session != NULL) {
2821 nb_chan = hashtable_get_count(
2822 session->ust_session->domain_global.channels);
2823 }
2824 DBG3("Number of UST global channels %ld", nb_chan);
2825 break;
2826 default:
2827 *channels = NULL;
2828 ret = -LTTCOMM_NOT_IMPLEMENTED;
2829 goto error;
2830 }
2831
2832 if (nb_chan > 0) {
2833 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2834 if (*channels == NULL) {
2835 ret = -LTTCOMM_FATAL;
2836 goto error;
2837 }
2838
2839 list_lttng_channels(domain, session, *channels);
2840 } else {
2841 *channels = NULL;
2842 }
2843
2844 return nb_chan;
2845
2846 error:
2847 return ret;
2848 }
2849
2850 /*
2851 * Command LTTNG_LIST_EVENTS processed by the client thread.
2852 */
2853 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
2854 char *channel_name, struct lttng_event **events)
2855 {
2856 int ret = 0;
2857 ssize_t nb_event = 0;
2858
2859 switch (domain) {
2860 case LTTNG_DOMAIN_KERNEL:
2861 if (session->kernel_session != NULL) {
2862 nb_event = list_lttng_kernel_events(channel_name,
2863 session->kernel_session, events);
2864 }
2865 break;
2866 case LTTNG_DOMAIN_UST:
2867 {
2868 if (session->ust_session != NULL) {
2869 nb_event = list_lttng_ust_global_events(channel_name,
2870 &session->ust_session->domain_global, events);
2871 }
2872 break;
2873 }
2874 default:
2875 ret = -LTTCOMM_NOT_IMPLEMENTED;
2876 goto error;
2877 }
2878
2879 ret = nb_event;
2880
2881 error:
2882 return ret;
2883 }
2884
2885 /*
2886 * Process the command requested by the lttng client within the command
2887 * context structure. This function make sure that the return structure (llm)
2888 * is set and ready for transmission before returning.
2889 *
2890 * Return any error encountered or 0 for success.
2891 */
2892 static int process_client_msg(struct command_ctx *cmd_ctx)
2893 {
2894 int ret = LTTCOMM_OK;
2895 int need_tracing_session = 1;
2896
2897 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
2898
2899 /*
2900 * Check for command that don't needs to allocate a returned payload. We do
2901 * this here so we don't have to make the call for no payload at each
2902 * command.
2903 */
2904 switch(cmd_ctx->lsm->cmd_type) {
2905 case LTTNG_LIST_SESSIONS:
2906 case LTTNG_LIST_TRACEPOINTS:
2907 case LTTNG_LIST_DOMAINS:
2908 case LTTNG_LIST_CHANNELS:
2909 case LTTNG_LIST_EVENTS:
2910 break;
2911 default:
2912 /* Setup lttng message with no payload */
2913 ret = setup_lttng_msg(cmd_ctx, 0);
2914 if (ret < 0) {
2915 /* This label does not try to unlock the session */
2916 goto init_setup_error;
2917 }
2918 }
2919
2920 /* Commands that DO NOT need a session. */
2921 switch (cmd_ctx->lsm->cmd_type) {
2922 case LTTNG_CALIBRATE:
2923 case LTTNG_CREATE_SESSION:
2924 case LTTNG_LIST_SESSIONS:
2925 case LTTNG_LIST_TRACEPOINTS:
2926 need_tracing_session = 0;
2927 break;
2928 default:
2929 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
2930 session_lock_list();
2931 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
2932 session_unlock_list();
2933 if (cmd_ctx->session == NULL) {
2934 if (cmd_ctx->lsm->session.name != NULL) {
2935 ret = LTTCOMM_SESS_NOT_FOUND;
2936 } else {
2937 /* If no session name specified */
2938 ret = LTTCOMM_SELECT_SESS;
2939 }
2940 goto error;
2941 } else {
2942 /* Acquire lock for the session */
2943 session_lock(cmd_ctx->session);
2944 }
2945 break;
2946 }
2947
2948 /*
2949 * Check domain type for specific "pre-action".
2950 */
2951 switch (cmd_ctx->lsm->domain.type) {
2952 case LTTNG_DOMAIN_KERNEL:
2953 /* Kernel tracer check */
2954 if (kernel_tracer_fd == 0) {
2955 /* Basically, load kernel tracer modules */
2956 init_kernel_tracer();
2957 if (kernel_tracer_fd == 0) {
2958 ret = LTTCOMM_KERN_NA;
2959 goto error;
2960 }
2961 }
2962
2963 /* Need a session for kernel command */
2964 if (need_tracing_session) {
2965 if (cmd_ctx->session->kernel_session == NULL) {
2966 ret = create_kernel_session(cmd_ctx->session);
2967 if (ret < 0) {
2968 ret = LTTCOMM_KERN_SESS_FAIL;
2969 goto error;
2970 }
2971 }
2972
2973 /* Start the kernel consumer daemon */
2974 pthread_mutex_lock(&kconsumer_data.pid_mutex);
2975 if (kconsumer_data.pid == 0 &&
2976 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
2977 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2978 ret = start_consumerd(&kconsumer_data);
2979 if (ret < 0) {
2980 ret = LTTCOMM_KERN_CONSUMER_FAIL;
2981 goto error;
2982 }
2983 }
2984 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2985 }
2986 break;
2987 case LTTNG_DOMAIN_UST:
2988 {
2989 if (need_tracing_session) {
2990 if (cmd_ctx->session->ust_session == NULL) {
2991 ret = create_ust_session(cmd_ctx->session,
2992 &cmd_ctx->lsm->domain);
2993 if (ret != LTTCOMM_OK) {
2994 goto error;
2995 }
2996 }
2997 /* Start the kernel consumer daemon */
2998 pthread_mutex_lock(&ustconsumer_data.pid_mutex);
2999 if (ustconsumer_data.pid == 0 &&
3000 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3001 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3002 ret = start_consumerd(&ustconsumer_data);
3003 if (ret < 0) {
3004 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3005 goto error;
3006 }
3007
3008 cmd_ctx->session->ust_session->consumer_fd =
3009 ustconsumer_data.cmd_sock;
3010 }
3011 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3012 }
3013 break;
3014 }
3015 default:
3016 break;
3017 }
3018
3019 /* Process by command type */
3020 switch (cmd_ctx->lsm->cmd_type) {
3021 case LTTNG_ADD_CONTEXT:
3022 {
3023 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3024 cmd_ctx->lsm->u.context.channel_name,
3025 cmd_ctx->lsm->u.context.event_name,
3026 &cmd_ctx->lsm->u.context.ctx);
3027 break;
3028 }
3029 case LTTNG_DISABLE_CHANNEL:
3030 {
3031 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3032 cmd_ctx->lsm->u.disable.channel_name);
3033 break;
3034 }
3035 case LTTNG_DISABLE_EVENT:
3036 {
3037 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3038 cmd_ctx->lsm->u.disable.channel_name,
3039 cmd_ctx->lsm->u.disable.name);
3040 ret = LTTCOMM_OK;
3041 break;
3042 }
3043 case LTTNG_DISABLE_ALL_EVENT:
3044 {
3045 DBG("Disabling all events");
3046
3047 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3048 cmd_ctx->lsm->u.disable.channel_name);
3049 break;
3050 }
3051 case LTTNG_ENABLE_CHANNEL:
3052 {
3053 ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
3054 &cmd_ctx->lsm->u.channel.chan);
3055 break;
3056 }
3057 case LTTNG_ENABLE_EVENT:
3058 {
3059 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3060 cmd_ctx->lsm->u.enable.channel_name,
3061 &cmd_ctx->lsm->u.enable.event);
3062 break;
3063 }
3064 case LTTNG_ENABLE_ALL_EVENT:
3065 {
3066 DBG("Enabling all events");
3067
3068 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3069 cmd_ctx->lsm->u.enable.channel_name,
3070 cmd_ctx->lsm->u.enable.event.type);
3071 break;
3072 }
3073 case LTTNG_LIST_TRACEPOINTS:
3074 {
3075 struct lttng_event *events;
3076 ssize_t nb_events;
3077
3078 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
3079 if (nb_events < 0) {
3080 ret = -nb_events;
3081 goto error;
3082 }
3083
3084 /*
3085 * Setup lttng message with payload size set to the event list size in
3086 * bytes and then copy list into the llm payload.
3087 */
3088 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
3089 if (ret < 0) {
3090 free(events);
3091 goto setup_error;
3092 }
3093
3094 /* Copy event list into message payload */
3095 memcpy(cmd_ctx->llm->payload, events,
3096 sizeof(struct lttng_event) * nb_events);
3097
3098 free(events);
3099
3100 ret = LTTCOMM_OK;
3101 break;
3102 }
3103 case LTTNG_START_TRACE:
3104 {
3105 ret = cmd_start_trace(cmd_ctx->session);
3106 break;
3107 }
3108 case LTTNG_STOP_TRACE:
3109 {
3110 ret = cmd_stop_trace(cmd_ctx->session);
3111 break;
3112 }
3113 case LTTNG_CREATE_SESSION:
3114 {
3115 ret = cmd_create_session(cmd_ctx->lsm->session.name,
3116 cmd_ctx->lsm->session.path);
3117 break;
3118 }
3119 case LTTNG_DESTROY_SESSION:
3120 {
3121 ret = cmd_destroy_session(cmd_ctx->session,
3122 cmd_ctx->lsm->session.name);
3123 break;
3124 }
3125 case LTTNG_LIST_DOMAINS:
3126 {
3127 ssize_t nb_dom;
3128 struct lttng_domain *domains;
3129
3130 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
3131 if (nb_dom < 0) {
3132 ret = -nb_dom;
3133 goto error;
3134 }
3135
3136 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
3137 if (ret < 0) {
3138 goto setup_error;
3139 }
3140
3141 /* Copy event list into message payload */
3142 memcpy(cmd_ctx->llm->payload, domains,
3143 nb_dom * sizeof(struct lttng_domain));
3144
3145 free(domains);
3146
3147 ret = LTTCOMM_OK;
3148 break;
3149 }
3150 case LTTNG_LIST_CHANNELS:
3151 {
3152 size_t nb_chan;
3153 struct lttng_channel *channels;
3154
3155 nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
3156 cmd_ctx->session, &channels);
3157 if (nb_chan < 0) {
3158 ret = -nb_chan;
3159 goto error;
3160 }
3161
3162 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3163 if (ret < 0) {
3164 goto setup_error;
3165 }
3166
3167 /* Copy event list into message payload */
3168 memcpy(cmd_ctx->llm->payload, channels,
3169 nb_chan * sizeof(struct lttng_channel));
3170
3171 free(channels);
3172
3173 ret = LTTCOMM_OK;
3174 break;
3175 }
3176 case LTTNG_LIST_EVENTS:
3177 {
3178 ssize_t nb_event;
3179 struct lttng_event *events = NULL;
3180
3181 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
3182 cmd_ctx->lsm->u.list.channel_name, &events);
3183 if (nb_event < 0) {
3184 ret = -nb_event;
3185 goto error;
3186 }
3187
3188 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3189 if (ret < 0) {
3190 goto setup_error;
3191 }
3192
3193 /* Copy event list into message payload */
3194 memcpy(cmd_ctx->llm->payload, events,
3195 nb_event * sizeof(struct lttng_event));
3196
3197 free(events);
3198
3199 ret = LTTCOMM_OK;
3200 break;
3201 }
3202 case LTTNG_LIST_SESSIONS:
3203 {
3204 session_lock_list();
3205
3206 if (session_list_ptr->count == 0) {
3207 ret = LTTCOMM_NO_SESSION;
3208 session_unlock_list();
3209 goto error;
3210 }
3211
3212 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
3213 session_list_ptr->count);
3214 if (ret < 0) {
3215 session_unlock_list();
3216 goto setup_error;
3217 }
3218
3219 /* Filled the session array */
3220 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
3221
3222 session_unlock_list();
3223
3224 ret = LTTCOMM_OK;
3225 break;
3226 }
3227 case LTTNG_CALIBRATE:
3228 {
3229 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3230 &cmd_ctx->lsm->u.calibrate);
3231 break;
3232 }
3233 case LTTNG_REGISTER_CONSUMER:
3234 {
3235 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3236 cmd_ctx->lsm->u.reg.path);
3237 break;
3238 }
3239 default:
3240 ret = LTTCOMM_UND;
3241 break;
3242 }
3243
3244 error:
3245 if (cmd_ctx->llm == NULL) {
3246 DBG("Missing llm structure. Allocating one.");
3247 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3248 goto setup_error;
3249 }
3250 }
3251 /* Set return code */
3252 cmd_ctx->llm->ret_code = ret;
3253 setup_error:
3254 if (cmd_ctx->session) {
3255 session_unlock(cmd_ctx->session);
3256 }
3257 init_setup_error:
3258 return ret;
3259 }
3260
3261 /*
3262 * This thread manage all clients request using the unix client socket for
3263 * communication.
3264 */
3265 static void *thread_manage_clients(void *data)
3266 {
3267 int sock = 0, ret, i, pollfd;
3268 uint32_t revents, nb_fd;
3269 struct command_ctx *cmd_ctx = NULL;
3270 struct lttng_poll_event events;
3271
3272 DBG("[thread] Manage client started");
3273
3274 rcu_register_thread();
3275
3276 ret = lttcomm_listen_unix_sock(client_sock);
3277 if (ret < 0) {
3278 goto error;
3279 }
3280
3281 /*
3282 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
3283 * more will be added to this poll set.
3284 */
3285 ret = create_thread_poll_set(&events, 2);
3286 if (ret < 0) {
3287 goto error;
3288 }
3289
3290 /* Add the application registration socket */
3291 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
3292 if (ret < 0) {
3293 goto error;
3294 }
3295
3296 /*
3297 * Notify parent pid that we are ready to accept command for client side.
3298 */
3299 if (opt_sig_parent) {
3300 kill(ppid, SIGCHLD);
3301 }
3302
3303 while (1) {
3304 DBG("Accepting client command ...");
3305
3306 nb_fd = LTTNG_POLL_GETNB(&events);
3307
3308 /* Inifinite blocking call, waiting for transmission */
3309 ret = lttng_poll_wait(&events, -1);
3310 if (ret < 0) {
3311 goto error;
3312 }
3313
3314 for (i = 0; i < nb_fd; i++) {
3315 /* Fetch once the poll data */
3316 revents = LTTNG_POLL_GETEV(&events, i);
3317 pollfd = LTTNG_POLL_GETFD(&events, i);
3318
3319 /* Thread quit pipe has been closed. Killing thread. */
3320 ret = check_thread_quit_pipe(pollfd, revents);
3321 if (ret) {
3322 goto error;
3323 }
3324
3325 /* Event on the registration socket */
3326 if (pollfd == client_sock) {
3327 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3328 ERR("Client socket poll error");
3329 goto error;
3330 }
3331 }
3332 }
3333
3334 DBG("Wait for client response");
3335
3336 sock = lttcomm_accept_unix_sock(client_sock);
3337 if (sock < 0) {
3338 goto error;
3339 }
3340
3341 /* Allocate context command to process the client request */
3342 cmd_ctx = malloc(sizeof(struct command_ctx));
3343 if (cmd_ctx == NULL) {
3344 perror("malloc cmd_ctx");
3345 goto error;
3346 }
3347
3348 /* Allocate data buffer for reception */
3349 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
3350 if (cmd_ctx->lsm == NULL) {
3351 perror("malloc cmd_ctx->lsm");
3352 goto error;
3353 }
3354
3355 cmd_ctx->llm = NULL;
3356 cmd_ctx->session = NULL;
3357
3358 /*
3359 * Data is received from the lttng client. The struct
3360 * lttcomm_session_msg (lsm) contains the command and data request of
3361 * the client.
3362 */
3363 DBG("Receiving data from client ...");
3364 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm,
3365 sizeof(struct lttcomm_session_msg));
3366 if (ret <= 0) {
3367 DBG("Nothing recv() from client... continuing");
3368 close(sock);
3369 free(cmd_ctx);
3370 continue;
3371 }
3372
3373 // TODO: Validate cmd_ctx including sanity check for
3374 // security purpose.
3375
3376 rcu_thread_online();
3377 /*
3378 * This function dispatch the work to the kernel or userspace tracer
3379 * libs and fill the lttcomm_lttng_msg data structure of all the needed
3380 * informations for the client. The command context struct contains
3381 * everything this function may needs.
3382 */
3383 ret = process_client_msg(cmd_ctx);
3384 rcu_thread_offline();
3385 if (ret < 0) {
3386 /*
3387 * TODO: Inform client somehow of the fatal error. At
3388 * this point, ret < 0 means that a malloc failed
3389 * (ENOMEM). Error detected but still accept command.
3390 */
3391 clean_command_ctx(&cmd_ctx);
3392 continue;
3393 }
3394
3395 DBG("Sending response (size: %d, retcode: %s)",
3396 cmd_ctx->lttng_msg_size,
3397 lttng_strerror(-cmd_ctx->llm->ret_code));
3398 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
3399 if (ret < 0) {
3400 ERR("Failed to send data back to client");
3401 }
3402
3403 clean_command_ctx(&cmd_ctx);
3404
3405 /* End of transmission */
3406 close(sock);
3407 }
3408
3409 error:
3410 DBG("Client thread dying");
3411 unlink(client_unix_sock_path);
3412 close(client_sock);
3413 close(sock);
3414
3415 lttng_poll_clean(&events);
3416 clean_command_ctx(&cmd_ctx);
3417
3418 rcu_unregister_thread();
3419 return NULL;
3420 }
3421
3422
3423 /*
3424 * usage function on stderr
3425 */
3426 static void usage(void)
3427 {
3428 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
3429 fprintf(stderr, " -h, --help Display this usage.\n");
3430 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
3431 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
3432 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
3433 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
3434 fprintf(stderr, " --ustconsumerd-err-sock PATH Specify path for the UST consumer error socket\n");
3435 fprintf(stderr, " --ustconsumerd-cmd-sock PATH Specify path for the UST consumer command socket\n");
3436 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
3437 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
3438 fprintf(stderr, " -V, --version Show version number.\n");
3439 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
3440 fprintf(stderr, " -q, --quiet No output at all.\n");
3441 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
3442 fprintf(stderr, " --verbose-consumer Verbose mode for consumer. Activate DBG() macro.\n");
3443 }
3444
3445 /*
3446 * daemon argument parsing
3447 */
3448 static int parse_args(int argc, char **argv)
3449 {
3450 int c;
3451
3452 static struct option long_options[] = {
3453 { "client-sock", 1, 0, 'c' },
3454 { "apps-sock", 1, 0, 'a' },
3455 { "kconsumerd-cmd-sock", 1, 0, 'C' },
3456 { "kconsumerd-err-sock", 1, 0, 'E' },
3457 { "ustconsumerd-cmd-sock", 1, 0, 'D' },
3458 { "ustconsumerd-err-sock", 1, 0, 'F' },
3459 { "daemonize", 0, 0, 'd' },
3460 { "sig-parent", 0, 0, 'S' },
3461 { "help", 0, 0, 'h' },
3462 { "group", 1, 0, 'g' },
3463 { "version", 0, 0, 'V' },
3464 { "quiet", 0, 0, 'q' },
3465 { "verbose", 0, 0, 'v' },
3466 { "verbose-consumer", 0, 0, 'Z' },
3467 { NULL, 0, 0, 0 }
3468 };
3469
3470 while (1) {
3471 int option_index = 0;
3472 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:C:E:D:F:Z",
3473 long_options, &option_index);
3474 if (c == -1) {
3475 break;
3476 }
3477
3478 switch (c) {
3479 case 0:
3480 fprintf(stderr, "option %s", long_options[option_index].name);
3481 if (optarg) {
3482 fprintf(stderr, " with arg %s\n", optarg);
3483 }
3484 break;
3485 case 'c':
3486 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
3487 break;
3488 case 'a':
3489 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
3490 break;
3491 case 'd':
3492 opt_daemon = 1;
3493 break;
3494 case 'g':
3495 opt_tracing_group = strdup(optarg);
3496 break;
3497 case 'h':
3498 usage();
3499 exit(EXIT_FAILURE);
3500 case 'V':
3501 fprintf(stdout, "%s\n", VERSION);
3502 exit(EXIT_SUCCESS);
3503 case 'S':
3504 opt_sig_parent = 1;
3505 break;
3506 case 'E':
3507 snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3508 break;
3509 case 'C':
3510 snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3511 break;
3512 case 'F':
3513 snprintf(ustconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3514 break;
3515 case 'D':
3516 snprintf(ustconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3517 break;
3518 case 'q':
3519 opt_quiet = 1;
3520 break;
3521 case 'v':
3522 /* Verbose level can increase using multiple -v */
3523 opt_verbose += 1;
3524 break;
3525 case 'Z':
3526 opt_verbose_consumer += 1;
3527 break;
3528 default:
3529 /* Unknown option or other error.
3530 * Error is printed by getopt, just return */
3531 return -1;
3532 }
3533 }
3534
3535 return 0;
3536 }
3537
3538 /*
3539 * Creates the two needed socket by the daemon.
3540 * apps_sock - The communication socket for all UST apps.
3541 * client_sock - The communication of the cli tool (lttng).
3542 */
3543 static int init_daemon_socket(void)
3544 {
3545 int ret = 0;
3546 mode_t old_umask;
3547
3548 old_umask = umask(0);
3549
3550 /* Create client tool unix socket */
3551 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
3552 if (client_sock < 0) {
3553 ERR("Create unix sock failed: %s", client_unix_sock_path);
3554 ret = -1;
3555 goto end;
3556 }
3557
3558 /* File permission MUST be 660 */
3559 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3560 if (ret < 0) {
3561 ERR("Set file permissions failed: %s", client_unix_sock_path);
3562 perror("chmod");
3563 goto end;
3564 }
3565
3566 /* Create the application unix socket */
3567 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
3568 if (apps_sock < 0) {
3569 ERR("Create unix sock failed: %s", apps_unix_sock_path);
3570 ret = -1;
3571 goto end;
3572 }
3573
3574 /* File permission MUST be 666 */
3575 ret = chmod(apps_unix_sock_path,
3576 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
3577 if (ret < 0) {
3578 ERR("Set file permissions failed: %s", apps_unix_sock_path);
3579 perror("chmod");
3580 goto end;
3581 }
3582
3583 end:
3584 umask(old_umask);
3585 return ret;
3586 }
3587
3588 /*
3589 * Check if the global socket is available, and if a daemon is answering at the
3590 * other side. If yes, error is returned.
3591 */
3592 static int check_existing_daemon(void)
3593 {
3594 if (access(client_unix_sock_path, F_OK) < 0 &&
3595 access(apps_unix_sock_path, F_OK) < 0) {
3596 return 0;
3597 }
3598
3599 /* Is there anybody out there ? */
3600 if (lttng_session_daemon_alive()) {
3601 return -EEXIST;
3602 } else {
3603 return 0;
3604 }
3605 }
3606
3607 /*
3608 * Set the tracing group gid onto the client socket.
3609 *
3610 * Race window between mkdir and chown is OK because we are going from more
3611 * permissive (root.root) to les permissive (root.tracing).
3612 */
3613 static int set_permissions(void)
3614 {
3615 int ret;
3616 gid_t gid;
3617
3618 gid = allowed_group();
3619 if (gid < 0) {
3620 if (is_root) {
3621 WARN("No tracing group detected");
3622 ret = 0;
3623 } else {
3624 ERR("Missing tracing group. Aborting execution.");
3625 ret = -1;
3626 }
3627 goto end;
3628 }
3629
3630 /* Set lttng run dir */
3631 ret = chown(LTTNG_RUNDIR, 0, gid);
3632 if (ret < 0) {
3633 ERR("Unable to set group on " LTTNG_RUNDIR);
3634 perror("chown");
3635 }
3636
3637 /* lttng client socket path */
3638 ret = chown(client_unix_sock_path, 0, gid);
3639 if (ret < 0) {
3640 ERR("Unable to set group on %s", client_unix_sock_path);
3641 perror("chown");
3642 }
3643
3644 /* kconsumer error socket path */
3645 ret = chown(kconsumer_data.err_unix_sock_path, 0, gid);
3646 if (ret < 0) {
3647 ERR("Unable to set group on %s", kconsumer_data.err_unix_sock_path);
3648 perror("chown");
3649 }
3650
3651 /* ustconsumer error socket path */
3652 ret = chown(ustconsumer_data.err_unix_sock_path, 0, gid);
3653 if (ret < 0) {
3654 ERR("Unable to set group on %s", ustconsumer_data.err_unix_sock_path);
3655 perror("chown");
3656 }
3657
3658 DBG("All permissions are set");
3659
3660 end:
3661 return ret;
3662 }
3663
3664 /*
3665 * Create the pipe used to wake up the kernel thread.
3666 */
3667 static int create_kernel_poll_pipe(void)
3668 {
3669 return pipe2(kernel_poll_pipe, O_CLOEXEC);
3670 }
3671
3672 /*
3673 * Create the application command pipe to wake thread_manage_apps.
3674 */
3675 static int create_apps_cmd_pipe(void)
3676 {
3677 return pipe2(apps_cmd_pipe, O_CLOEXEC);
3678 }
3679
3680 /*
3681 * Create the lttng run directory needed for all global sockets and pipe.
3682 */
3683 static int create_lttng_rundir(void)
3684 {
3685 int ret;
3686
3687 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
3688 if (ret < 0) {
3689 if (errno != EEXIST) {
3690 ERR("Unable to create " LTTNG_RUNDIR);
3691 goto error;
3692 } else {
3693 ret = 0;
3694 }
3695 }
3696
3697 error:
3698 return ret;
3699 }
3700
3701 /*
3702 * Setup sockets and directory needed by the kconsumerd communication with the
3703 * session daemon.
3704 */
3705 static int set_consumer_sockets(struct consumer_data *consumer_data)
3706 {
3707 int ret;
3708 const char *path = consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3709 KCONSUMERD_PATH : USTCONSUMERD_PATH;
3710
3711 if (strlen(consumer_data->err_unix_sock_path) == 0) {
3712 snprintf(consumer_data->err_unix_sock_path, PATH_MAX,
3713 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3714 KCONSUMERD_ERR_SOCK_PATH :
3715 USTCONSUMERD_ERR_SOCK_PATH);
3716 }
3717
3718 if (strlen(consumer_data->cmd_unix_sock_path) == 0) {
3719 snprintf(consumer_data->cmd_unix_sock_path, PATH_MAX,
3720 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3721 KCONSUMERD_CMD_SOCK_PATH :
3722 USTCONSUMERD_CMD_SOCK_PATH);
3723 }
3724
3725 ret = mkdir(path, S_IRWXU | S_IRWXG);
3726 if (ret < 0) {
3727 if (errno != EEXIST) {
3728 ERR("Failed to create %s", path);
3729 goto error;
3730 }
3731 ret = 0;
3732 }
3733
3734 /* Create the kconsumerd error unix socket */
3735 consumer_data->err_sock =
3736 lttcomm_create_unix_sock(consumer_data->err_unix_sock_path);
3737 if (consumer_data->err_sock < 0) {
3738 ERR("Create unix sock failed: %s", consumer_data->err_unix_sock_path);
3739 ret = -1;
3740 goto error;
3741 }
3742
3743 /* File permission MUST be 660 */
3744 ret = chmod(consumer_data->err_unix_sock_path,
3745 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3746 if (ret < 0) {
3747 ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
3748 perror("chmod");
3749 goto error;
3750 }
3751
3752 error:
3753 return ret;
3754 }
3755
3756 /*
3757 * Signal handler for the daemon
3758 *
3759 * Simply stop all worker threads, leaving main() return gracefully after
3760 * joining all threads and calling cleanup().
3761 */
3762 static void sighandler(int sig)
3763 {
3764 switch (sig) {
3765 case SIGPIPE:
3766 DBG("SIGPIPE catched");
3767 return;
3768 case SIGINT:
3769 DBG("SIGINT catched");
3770 stop_threads();
3771 break;
3772 case SIGTERM:
3773 DBG("SIGTERM catched");
3774 stop_threads();
3775 break;
3776 default:
3777 break;
3778 }
3779 }
3780
3781 /*
3782 * Setup signal handler for :
3783 * SIGINT, SIGTERM, SIGPIPE
3784 */
3785 static int set_signal_handler(void)
3786 {
3787 int ret = 0;
3788 struct sigaction sa;
3789 sigset_t sigset;
3790
3791 if ((ret = sigemptyset(&sigset)) < 0) {
3792 perror("sigemptyset");
3793 return ret;
3794 }
3795
3796 sa.sa_handler = sighandler;
3797 sa.sa_mask = sigset;
3798 sa.sa_flags = 0;
3799 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
3800 perror("sigaction");
3801 return ret;
3802 }
3803
3804 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
3805 perror("sigaction");
3806 return ret;
3807 }
3808
3809 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
3810 perror("sigaction");
3811 return ret;
3812 }
3813
3814 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
3815
3816 return ret;
3817 }
3818
3819 /*
3820 * Set open files limit to unlimited. This daemon can open a large number of
3821 * file descriptors in order to consumer multiple kernel traces.
3822 */
3823 static void set_ulimit(void)
3824 {
3825 int ret;
3826 struct rlimit lim;
3827
3828 /* The kernel does not allowed an infinite limit for open files */
3829 lim.rlim_cur = 65535;
3830 lim.rlim_max = 65535;
3831
3832 ret = setrlimit(RLIMIT_NOFILE, &lim);
3833 if (ret < 0) {
3834 perror("failed to set open files limit");
3835 }
3836 }
3837
3838 /*
3839 * main
3840 */
3841 int main(int argc, char **argv)
3842 {
3843 int ret = 0;
3844 void *status;
3845 const char *home_path;
3846
3847 rcu_register_thread();
3848
3849 /* Create thread quit pipe */
3850 if ((ret = init_thread_quit_pipe()) < 0) {
3851 goto error;
3852 }
3853
3854 /* Parse arguments */
3855 progname = argv[0];
3856 if ((ret = parse_args(argc, argv) < 0)) {
3857 goto error;
3858 }
3859
3860 /* Daemonize */
3861 if (opt_daemon) {
3862 ret = daemon(0, 0);
3863 if (ret < 0) {
3864 perror("daemon");
3865 goto error;
3866 }
3867 }
3868
3869 /* Check if daemon is UID = 0 */
3870 is_root = !getuid();
3871
3872 if (is_root) {
3873 ret = create_lttng_rundir();
3874 if (ret < 0) {
3875 goto error;
3876 }
3877
3878 if (strlen(apps_unix_sock_path) == 0) {
3879 snprintf(apps_unix_sock_path, PATH_MAX,
3880 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
3881 }
3882
3883 if (strlen(client_unix_sock_path) == 0) {
3884 snprintf(client_unix_sock_path, PATH_MAX,
3885 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
3886 }
3887
3888 /* Set global SHM for ust */
3889 if (strlen(wait_shm_path) == 0) {