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0acf230e0d09c9553be4e0f2a688b3c8ca8bc244
[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 int ust_consumer_fd;
161
162 /*
163 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
164 */
165 static int create_thread_poll_set(struct lttng_poll_event *events,
166 unsigned int size)
167 {
168 int ret;
169
170 if (events == NULL || size == 0) {
171 ret = -1;
172 goto error;
173 }
174
175 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
176 if (ret < 0) {
177 goto error;
178 }
179
180 /* Add quit pipe */
181 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
182 if (ret < 0) {
183 goto error;
184 }
185
186 return 0;
187
188 error:
189 return ret;
190 }
191
192 /*
193 * Check if the thread quit pipe was triggered.
194 *
195 * Return 1 if it was triggered else 0;
196 */
197 static int check_thread_quit_pipe(int fd, uint32_t events)
198 {
199 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
200 return 1;
201 }
202
203 return 0;
204 }
205
206 /*
207 * Remove modules in reverse load order.
208 */
209 static int modprobe_remove_kernel_modules(void)
210 {
211 int ret = 0, i;
212 char modprobe[256];
213
214 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
215 ret = snprintf(modprobe, sizeof(modprobe),
216 "/sbin/modprobe -r -q %s",
217 kernel_modules_list[i].name);
218 if (ret < 0) {
219 perror("snprintf modprobe -r");
220 goto error;
221 }
222 modprobe[sizeof(modprobe) - 1] = '\0';
223 ret = system(modprobe);
224 if (ret == -1) {
225 ERR("Unable to launch modprobe -r for module %s",
226 kernel_modules_list[i].name);
227 } else if (kernel_modules_list[i].required
228 && WEXITSTATUS(ret) != 0) {
229 ERR("Unable to remove module %s",
230 kernel_modules_list[i].name);
231 } else {
232 DBG("Modprobe removal successful %s",
233 kernel_modules_list[i].name);
234 }
235 }
236
237 error:
238 return ret;
239 }
240
241 /*
242 * Return group ID of the tracing group or -1 if not found.
243 */
244 static gid_t allowed_group(void)
245 {
246 struct group *grp;
247
248 if (opt_tracing_group) {
249 grp = getgrnam(opt_tracing_group);
250 } else {
251 grp = getgrnam(default_tracing_group);
252 }
253 if (!grp) {
254 return -1;
255 } else {
256 return grp->gr_gid;
257 }
258 }
259
260 /*
261 * Init thread quit pipe.
262 *
263 * Return -1 on error or 0 if all pipes are created.
264 */
265 static int init_thread_quit_pipe(void)
266 {
267 int ret;
268
269 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
270 if (ret < 0) {
271 perror("thread quit pipe");
272 goto error;
273 }
274
275 error:
276 return ret;
277 }
278
279 /*
280 * Complete teardown of a kernel session. This free all data structure related
281 * to a kernel session and update counter.
282 */
283 static void teardown_kernel_session(struct ltt_session *session)
284 {
285 if (session->kernel_session != NULL) {
286 DBG("Tearing down kernel session");
287
288 /*
289 * If a custom kernel consumer was registered, close the socket before
290 * tearing down the complete kernel session structure
291 */
292 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
293 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
294 }
295
296 trace_kernel_destroy_session(session->kernel_session);
297 /* Extra precaution */
298 session->kernel_session = NULL;
299 }
300 }
301
302 /*
303 * Complete teardown of all UST sessions. This will free everything on his path
304 * and destroy the core essence of all ust sessions :)
305 */
306 static void teardown_ust_session(struct ltt_session *session)
307 {
308 int ret;
309
310 DBG("Tearing down UST session(s)");
311
312 ret = ust_app_destroy_trace_all(session->ust_session);
313 if (ret) {
314 ERR("Error in ust_app_destroy_trace_all");
315 }
316 trace_ust_destroy_session(session->ust_session);
317 }
318
319 /*
320 * Stop all threads by closing the thread quit pipe.
321 */
322 static void stop_threads(void)
323 {
324 int ret;
325
326 /* Stopping all threads */
327 DBG("Terminating all threads");
328 ret = notify_thread_pipe(thread_quit_pipe[1]);
329 if (ret < 0) {
330 ERR("write error on thread quit pipe");
331 }
332
333 /* Dispatch thread */
334 dispatch_thread_exit = 1;
335 futex_nto1_wake(&ust_cmd_queue.futex);
336 }
337
338 /*
339 * Cleanup the daemon
340 */
341 static void cleanup(void)
342 {
343 int ret;
344 char *cmd;
345 struct ltt_session *sess, *stmp;
346
347 DBG("Cleaning up");
348
349 if (is_root) {
350 DBG("Removing %s directory", LTTNG_RUNDIR);
351 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
352 if (ret < 0) {
353 ERR("asprintf failed. Something is really wrong!");
354 }
355
356 /* Remove lttng run directory */
357 ret = system(cmd);
358 if (ret < 0) {
359 ERR("Unable to clean " LTTNG_RUNDIR);
360 }
361 }
362
363 DBG("Cleaning up all session");
364
365 /* Destroy session list mutex */
366 if (session_list_ptr != NULL) {
367 pthread_mutex_destroy(&session_list_ptr->lock);
368
369 /* Cleanup ALL session */
370 cds_list_for_each_entry_safe(sess, stmp,
371 &session_list_ptr->head, list) {
372 teardown_kernel_session(sess);
373 teardown_ust_session(sess);
374 free(sess);
375 }
376 }
377
378 DBG("Closing all UST sockets");
379 ust_app_clean_list();
380
381 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
382
383 DBG("Closing kernel fd");
384 close(kernel_tracer_fd);
385
386 if (is_root) {
387 DBG("Unloading kernel modules");
388 modprobe_remove_kernel_modules();
389 }
390
391 close(thread_quit_pipe[0]);
392 close(thread_quit_pipe[1]);
393
394 /* <fun> */
395 MSG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
396 "Matthew, BEET driven development works!%c[%dm",
397 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
398 /* </fun> */
399 }
400
401 /*
402 * Send data on a unix socket using the liblttsessiondcomm API.
403 *
404 * Return lttcomm error code.
405 */
406 static int send_unix_sock(int sock, void *buf, size_t len)
407 {
408 /* Check valid length */
409 if (len <= 0) {
410 return -1;
411 }
412
413 return lttcomm_send_unix_sock(sock, buf, len);
414 }
415
416 /*
417 * Free memory of a command context structure.
418 */
419 static void clean_command_ctx(struct command_ctx **cmd_ctx)
420 {
421 DBG("Clean command context structure");
422 if (*cmd_ctx) {
423 if ((*cmd_ctx)->llm) {
424 free((*cmd_ctx)->llm);
425 }
426 if ((*cmd_ctx)->lsm) {
427 free((*cmd_ctx)->lsm);
428 }
429 free(*cmd_ctx);
430 *cmd_ctx = NULL;
431 }
432 }
433
434 /*
435 * Send all stream fds of kernel channel to the consumer.
436 */
437 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
438 int sock, struct ltt_kernel_channel *channel)
439 {
440 int ret;
441 struct ltt_kernel_stream *stream;
442 struct lttcomm_consumer_msg lkm;
443
444 DBG("Sending streams of channel %s to kernel consumer",
445 channel->channel->name);
446
447 /* Send channel */
448 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
449 lkm.u.channel.channel_key = channel->fd;
450 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
451 lkm.u.channel.mmap_len = 0; /* for kernel */
452 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
453 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
454 if (ret < 0) {
455 perror("send consumer channel");
456 goto error;
457 }
458
459 /* Send streams */
460 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
461 if (!stream->fd) {
462 continue;
463 }
464 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
465 lkm.u.stream.channel_key = channel->fd;
466 lkm.u.stream.stream_key = stream->fd;
467 lkm.u.stream.state = stream->state;
468 lkm.u.stream.output = channel->channel->attr.output;
469 lkm.u.stream.mmap_len = 0; /* for kernel */
470 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
471 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
472 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
473 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
474 if (ret < 0) {
475 perror("send consumer stream");
476 goto error;
477 }
478 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
479 if (ret < 0) {
480 perror("send consumer stream ancillary data");
481 goto error;
482 }
483 }
484
485 DBG("consumer channel streams sent");
486
487 return 0;
488
489 error:
490 return ret;
491 }
492
493 /*
494 * Send all stream fds of the kernel session to the consumer.
495 */
496 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
497 struct ltt_kernel_session *session)
498 {
499 int ret;
500 struct ltt_kernel_channel *chan;
501 struct lttcomm_consumer_msg lkm;
502 int sock = session->consumer_fd;
503
504 DBG("Sending metadata stream fd");
505
506 /* Extra protection. It's NOT supposed to be set to 0 at this point */
507 if (session->consumer_fd == 0) {
508 session->consumer_fd = consumer_data->cmd_sock;
509 }
510
511 if (session->metadata_stream_fd != 0) {
512 /* Send metadata channel fd */
513 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
514 lkm.u.channel.channel_key = session->metadata->fd;
515 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
516 lkm.u.channel.mmap_len = 0; /* for kernel */
517 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
518 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
519 if (ret < 0) {
520 perror("send consumer channel");
521 goto error;
522 }
523
524 /* Send metadata stream fd */
525 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
526 lkm.u.stream.channel_key = session->metadata->fd;
527 lkm.u.stream.stream_key = session->metadata_stream_fd;
528 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
529 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
530 lkm.u.stream.mmap_len = 0; /* for kernel */
531 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
532 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
533 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
534 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
535 if (ret < 0) {
536 perror("send consumer stream");
537 goto error;
538 }
539 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
540 if (ret < 0) {
541 perror("send consumer stream");
542 goto error;
543 }
544 }
545
546 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
547 ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
548 if (ret < 0) {
549 goto error;
550 }
551 }
552
553 DBG("consumer fds (metadata and channel streams) sent");
554
555 return 0;
556
557 error:
558 return ret;
559 }
560
561 /*
562 * Notify UST applications using the shm mmap futex.
563 */
564 static int notify_ust_apps(int active)
565 {
566 char *wait_shm_mmap;
567
568 DBG("Notifying applications of session daemon state: %d", active);
569
570 /* See shm.c for this call implying mmap, shm and futex calls */
571 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
572 if (wait_shm_mmap == NULL) {
573 goto error;
574 }
575
576 /* Wake waiting process */
577 futex_wait_update((int32_t *) wait_shm_mmap, active);
578
579 /* Apps notified successfully */
580 return 0;
581
582 error:
583 return -1;
584 }
585
586 /*
587 * Setup the outgoing data buffer for the response (llm) by allocating the
588 * right amount of memory and copying the original information from the lsm
589 * structure.
590 *
591 * Return total size of the buffer pointed by buf.
592 */
593 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
594 {
595 int ret, buf_size;
596
597 buf_size = size;
598
599 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
600 if (cmd_ctx->llm == NULL) {
601 perror("zmalloc");
602 ret = -ENOMEM;
603 goto error;
604 }
605
606 /* Copy common data */
607 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
608 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
609
610 cmd_ctx->llm->data_size = size;
611 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
612
613 return buf_size;
614
615 error:
616 return ret;
617 }
618
619 /*
620 * Update the kernel poll set of all channel fd available over all tracing
621 * session. Add the wakeup pipe at the end of the set.
622 */
623 static int update_kernel_poll(struct lttng_poll_event *events)
624 {
625 int ret;
626 struct ltt_session *session;
627 struct ltt_kernel_channel *channel;
628
629 DBG("Updating kernel poll set");
630
631 session_lock_list();
632 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
633 session_lock(session);
634 if (session->kernel_session == NULL) {
635 session_unlock(session);
636 continue;
637 }
638
639 cds_list_for_each_entry(channel,
640 &session->kernel_session->channel_list.head, list) {
641 /* Add channel fd to the kernel poll set */
642 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
643 if (ret < 0) {
644 session_unlock(session);
645 goto error;
646 }
647 DBG("Channel fd %d added to kernel set", channel->fd);
648 }
649 session_unlock(session);
650 }
651 session_unlock_list();
652
653 return 0;
654
655 error:
656 session_unlock_list();
657 return -1;
658 }
659
660 /*
661 * Find the channel fd from 'fd' over all tracing session. When found, check
662 * for new channel stream and send those stream fds to the kernel consumer.
663 *
664 * Useful for CPU hotplug feature.
665 */
666 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
667 {
668 int ret = 0;
669 struct ltt_session *session;
670 struct ltt_kernel_channel *channel;
671
672 DBG("Updating kernel streams for channel fd %d", fd);
673
674 session_lock_list();
675 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
676 session_lock(session);
677 if (session->kernel_session == NULL) {
678 session_unlock(session);
679 continue;
680 }
681
682 /* This is not suppose to be 0 but this is an extra security check */
683 if (session->kernel_session->consumer_fd == 0) {
684 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
685 }
686
687 cds_list_for_each_entry(channel,
688 &session->kernel_session->channel_list.head, list) {
689 if (channel->fd == fd) {
690 DBG("Channel found, updating kernel streams");
691 ret = kernel_open_channel_stream(channel);
692 if (ret < 0) {
693 goto error;
694 }
695
696 /*
697 * Have we already sent fds to the consumer? If yes, it means
698 * that tracing is started so it is safe to send our updated
699 * stream fds.
700 */
701 if (session->kernel_session->consumer_fds_sent == 1) {
702 ret = send_kconsumer_channel_streams(consumer_data,
703 session->kernel_session->consumer_fd, channel);
704 if (ret < 0) {
705 goto error;
706 }
707 }
708 goto error;
709 }
710 }
711 session_unlock(session);
712 }
713 session_unlock_list();
714 return ret;
715
716 error:
717 session_unlock(session);
718 session_unlock_list();
719 return ret;
720 }
721
722 /*
723 * For each tracing session, update newly registered apps.
724 */
725 static void update_ust_app(int app_sock)
726 {
727 struct ltt_session *sess, *stmp;
728
729 /* For all tracing session(s) */
730 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
731 if (sess->ust_session) {
732 ust_app_global_update(sess->ust_session, app_sock);
733 }
734 }
735 }
736
737 /*
738 * This thread manage event coming from the kernel.
739 *
740 * Features supported in this thread:
741 * -) CPU Hotplug
742 */
743 static void *thread_manage_kernel(void *data)
744 {
745 int ret, i, pollfd, update_poll_flag = 1;
746 uint32_t revents, nb_fd;
747 char tmp;
748 struct lttng_poll_event events;
749
750 DBG("Thread manage kernel started");
751
752 ret = create_thread_poll_set(&events, 2);
753 if (ret < 0) {
754 goto error;
755 }
756
757 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
758 if (ret < 0) {
759 goto error;
760 }
761
762 while (1) {
763 if (update_poll_flag == 1) {
764 /*
765 * Reset number of fd in the poll set. Always 2 since there is the thread
766 * quit pipe and the kernel pipe.
767 */
768 events.nb_fd = 2;
769
770 ret = update_kernel_poll(&events);
771 if (ret < 0) {
772 goto error;
773 }
774 update_poll_flag = 0;
775 }
776
777 nb_fd = LTTNG_POLL_GETNB(&events);
778
779 DBG("Thread kernel polling on %d fds", nb_fd);
780
781 /* Zeroed the poll events */
782 lttng_poll_reset(&events);
783
784 /* Poll infinite value of time */
785 ret = lttng_poll_wait(&events, -1);
786 if (ret < 0) {
787 goto error;
788 } else if (ret == 0) {
789 /* Should not happen since timeout is infinite */
790 ERR("Return value of poll is 0 with an infinite timeout.\n"
791 "This should not have happened! Continuing...");
792 continue;
793 }
794
795 for (i = 0; i < nb_fd; i++) {
796 /* Fetch once the poll data */
797 revents = LTTNG_POLL_GETEV(&events, i);
798 pollfd = LTTNG_POLL_GETFD(&events, i);
799
800 /* Thread quit pipe has been closed. Killing thread. */
801 ret = check_thread_quit_pipe(pollfd, revents);
802 if (ret) {
803 goto error;
804 }
805
806 /* Check for data on kernel pipe */
807 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
808 ret = read(kernel_poll_pipe[0], &tmp, 1);
809 update_poll_flag = 1;
810 continue;
811 } else {
812 /*
813 * New CPU detected by the kernel. Adding kernel stream to
814 * kernel session and updating the kernel consumer
815 */
816 if (revents & LPOLLIN) {
817 ret = update_kernel_stream(&kconsumer_data, pollfd);
818 if (ret < 0) {
819 continue;
820 }
821 break;
822 /*
823 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
824 * and unregister kernel stream at this point.
825 */
826 }
827 }
828 }
829 }
830
831 error:
832 DBG("Kernel thread dying");
833 close(kernel_poll_pipe[0]);
834 close(kernel_poll_pipe[1]);
835
836 lttng_poll_clean(&events);
837
838 return NULL;
839 }
840
841 /*
842 * This thread manage the consumer error sent back to the session daemon.
843 */
844 static void *thread_manage_consumer(void *data)
845 {
846 int sock = 0, i, ret, pollfd;
847 uint32_t revents, nb_fd;
848 enum lttcomm_return_code code;
849 struct lttng_poll_event events;
850 struct consumer_data *consumer_data = data;
851
852 DBG("[thread] Manage consumer started");
853
854 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
855 if (ret < 0) {
856 goto error;
857 }
858
859 /*
860 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
861 * Nothing more will be added to this poll set.
862 */
863 ret = create_thread_poll_set(&events, 2);
864 if (ret < 0) {
865 goto error;
866 }
867
868 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
869 if (ret < 0) {
870 goto error;
871 }
872
873 nb_fd = LTTNG_POLL_GETNB(&events);
874
875 /* Inifinite blocking call, waiting for transmission */
876 ret = lttng_poll_wait(&events, -1);
877 if (ret < 0) {
878 goto error;
879 }
880
881 for (i = 0; i < nb_fd; i++) {
882 /* Fetch once the poll data */
883 revents = LTTNG_POLL_GETEV(&events, i);
884 pollfd = LTTNG_POLL_GETFD(&events, i);
885
886 /* Thread quit pipe has been closed. Killing thread. */
887 ret = check_thread_quit_pipe(pollfd, revents);
888 if (ret) {
889 goto error;
890 }
891
892 /* Event on the registration socket */
893 if (pollfd == consumer_data->err_sock) {
894 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
895 ERR("consumer err socket poll error");
896 goto error;
897 }
898 }
899 }
900
901 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
902 if (sock < 0) {
903 goto error;
904 }
905
906 DBG2("Receiving code from consumer err_sock");
907
908 /* Getting status code from kconsumerd */
909 ret = lttcomm_recv_unix_sock(sock, &code,
910 sizeof(enum lttcomm_return_code));
911 if (ret <= 0) {
912 goto error;
913 }
914
915 if (code == CONSUMERD_COMMAND_SOCK_READY) {
916 consumer_data->cmd_sock =
917 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
918 if (consumer_data->cmd_sock < 0) {
919 sem_post(&consumer_data->sem);
920 PERROR("consumer connect");
921 goto error;
922 }
923 /* Signal condition to tell that the kconsumerd is ready */
924 sem_post(&consumer_data->sem);
925 DBG("consumer command socket ready");
926 } else {
927 ERR("consumer error when waiting for SOCK_READY : %s",
928 lttcomm_get_readable_code(-code));
929 goto error;
930 }
931
932 /* Remove the kconsumerd error sock since we've established a connexion */
933 ret = lttng_poll_del(&events, consumer_data->err_sock);
934 if (ret < 0) {
935 goto error;
936 }
937
938 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
939 if (ret < 0) {
940 goto error;
941 }
942
943 /* Update number of fd */
944 nb_fd = LTTNG_POLL_GETNB(&events);
945
946 /* Inifinite blocking call, waiting for transmission */
947 ret = lttng_poll_wait(&events, -1);
948 if (ret < 0) {
949 goto error;
950 }
951
952 for (i = 0; i < nb_fd; i++) {
953 /* Fetch once the poll data */
954 revents = LTTNG_POLL_GETEV(&events, i);
955 pollfd = LTTNG_POLL_GETFD(&events, i);
956
957 /* Thread quit pipe has been closed. Killing thread. */
958 ret = check_thread_quit_pipe(pollfd, revents);
959 if (ret) {
960 goto error;
961 }
962
963 /* Event on the kconsumerd socket */
964 if (pollfd == sock) {
965 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
966 ERR("consumer err socket second poll error");
967 goto error;
968 }
969 }
970 }
971
972 /* Wait for any kconsumerd error */
973 ret = lttcomm_recv_unix_sock(sock, &code,
974 sizeof(enum lttcomm_return_code));
975 if (ret <= 0) {
976 ERR("consumer closed the command socket");
977 goto error;
978 }
979
980 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
981
982 error:
983 DBG("consumer thread dying");
984 close(consumer_data->err_sock);
985 close(consumer_data->cmd_sock);
986 close(sock);
987
988 unlink(consumer_data->err_unix_sock_path);
989 unlink(consumer_data->cmd_unix_sock_path);
990 consumer_data->pid = 0;
991
992 lttng_poll_clean(&events);
993
994 return NULL;
995 }
996
997 /*
998 * This thread manage application communication.
999 */
1000 static void *thread_manage_apps(void *data)
1001 {
1002 int i, ret, pollfd;
1003 uint32_t revents, nb_fd;
1004 struct ust_command ust_cmd;
1005 struct lttng_poll_event events;
1006
1007 DBG("[thread] Manage application started");
1008
1009 rcu_register_thread();
1010 rcu_thread_online();
1011
1012 ret = create_thread_poll_set(&events, 2);
1013 if (ret < 0) {
1014 goto error;
1015 }
1016
1017 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1018 if (ret < 0) {
1019 goto error;
1020 }
1021
1022 while (1) {
1023 /* Zeroed the events structure */
1024 lttng_poll_reset(&events);
1025
1026 nb_fd = LTTNG_POLL_GETNB(&events);
1027
1028 DBG("Apps thread polling on %d fds", nb_fd);
1029
1030 /* Inifinite blocking call, waiting for transmission */
1031 ret = lttng_poll_wait(&events, -1);
1032 if (ret < 0) {
1033 goto error;
1034 }
1035
1036 for (i = 0; i < nb_fd; i++) {
1037 /* Fetch once the poll data */
1038 revents = LTTNG_POLL_GETEV(&events, i);
1039 pollfd = LTTNG_POLL_GETFD(&events, i);
1040
1041 /* Thread quit pipe has been closed. Killing thread. */
1042 ret = check_thread_quit_pipe(pollfd, revents);
1043 if (ret) {
1044 goto error;
1045 }
1046
1047 /* Inspect the apps cmd pipe */
1048 if (pollfd == apps_cmd_pipe[0]) {
1049 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1050 ERR("Apps command pipe error");
1051 goto error;
1052 } else if (revents & LPOLLIN) {
1053 /* Empty pipe */
1054 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1055 if (ret < 0 || ret < sizeof(ust_cmd)) {
1056 perror("read apps cmd pipe");
1057 goto error;
1058 }
1059
1060 /* Register applicaton to the session daemon */
1061 ret = ust_app_register(&ust_cmd.reg_msg,
1062 ust_cmd.sock);
1063 if (ret < 0) {
1064 /* Only critical ENOMEM error can be returned here */
1065 goto error;
1066 }
1067
1068 /*
1069 * Add channel(s) and event(s) to newly registered apps
1070 * from lttng global UST domain.
1071 */
1072 update_ust_app(ust_cmd.sock);
1073
1074 ret = ustctl_register_done(ust_cmd.sock);
1075 if (ret < 0) {
1076 /*
1077 * If the registration is not possible, we simply
1078 * unregister the apps and continue
1079 */
1080 ust_app_unregister(ust_cmd.sock);
1081 } else {
1082 /*
1083 * We just need here to monitor the close of the UST
1084 * socket and poll set monitor those by default.
1085 */
1086 ret = lttng_poll_add(&events, ust_cmd.sock, 0);
1087 if (ret < 0) {
1088 goto error;
1089 }
1090
1091 DBG("Apps with sock %d added to poll set",
1092 ust_cmd.sock);
1093 }
1094
1095 break;
1096 }
1097 } else {
1098 /*
1099 * At this point, we know that a registered application made
1100 * the event at poll_wait.
1101 */
1102 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1103 /* Removing from the poll set */
1104 ret = lttng_poll_del(&events, pollfd);
1105 if (ret < 0) {
1106 goto error;
1107 }
1108
1109 /* Socket closed on remote end. */
1110 ust_app_unregister(pollfd);
1111 break;
1112 }
1113 }
1114 }
1115 }
1116
1117 error:
1118 DBG("Application communication apps dying");
1119 close(apps_cmd_pipe[0]);
1120 close(apps_cmd_pipe[1]);
1121
1122 lttng_poll_clean(&events);
1123
1124 rcu_thread_offline();
1125 rcu_unregister_thread();
1126 return NULL;
1127 }
1128
1129 /*
1130 * Dispatch request from the registration threads to the application
1131 * communication thread.
1132 */
1133 static void *thread_dispatch_ust_registration(void *data)
1134 {
1135 int ret;
1136 struct cds_wfq_node *node;
1137 struct ust_command *ust_cmd = NULL;
1138
1139 DBG("[thread] Dispatch UST command started");
1140
1141 while (!dispatch_thread_exit) {
1142 /* Atomically prepare the queue futex */
1143 futex_nto1_prepare(&ust_cmd_queue.futex);
1144
1145 do {
1146 /* Dequeue command for registration */
1147 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1148 if (node == NULL) {
1149 DBG("Woken up but nothing in the UST command queue");
1150 /* Continue thread execution */
1151 break;
1152 }
1153
1154 ust_cmd = caa_container_of(node, struct ust_command, node);
1155
1156 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1157 " gid:%d sock:%d name:%s (version %d.%d)",
1158 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1159 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1160 ust_cmd->sock, ust_cmd->reg_msg.name,
1161 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1162 /*
1163 * Inform apps thread of the new application registration. This
1164 * call is blocking so we can be assured that the data will be read
1165 * at some point in time or wait to the end of the world :)
1166 */
1167 ret = write(apps_cmd_pipe[1], ust_cmd,
1168 sizeof(struct ust_command));
1169 if (ret < 0) {
1170 perror("write apps cmd pipe");
1171 if (errno == EBADF) {
1172 /*
1173 * We can't inform the application thread to process
1174 * registration. We will exit or else application
1175 * registration will not occur and tracing will never
1176 * start.
1177 */
1178 goto error;
1179 }
1180 }
1181 free(ust_cmd);
1182 } while (node != NULL);
1183
1184 /* Futex wait on queue. Blocking call on futex() */
1185 futex_nto1_wait(&ust_cmd_queue.futex);
1186 }
1187
1188 error:
1189 DBG("Dispatch thread dying");
1190 return NULL;
1191 }
1192
1193 /*
1194 * This thread manage application registration.
1195 */
1196 static void *thread_registration_apps(void *data)
1197 {
1198 int sock = 0, i, ret, pollfd;
1199 uint32_t revents, nb_fd;
1200 struct lttng_poll_event events;
1201 /*
1202 * Get allocated in this thread, enqueued to a global queue, dequeued and
1203 * freed in the manage apps thread.
1204 */
1205 struct ust_command *ust_cmd = NULL;
1206
1207 DBG("[thread] Manage application registration started");
1208
1209 ret = lttcomm_listen_unix_sock(apps_sock);
1210 if (ret < 0) {
1211 goto error;
1212 }
1213
1214 /*
1215 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1216 * more will be added to this poll set.
1217 */
1218 ret = create_thread_poll_set(&events, 2);
1219 if (ret < 0) {
1220 goto error;
1221 }
1222
1223 /* Add the application registration socket */
1224 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1225 if (ret < 0) {
1226 goto error;
1227 }
1228
1229 /* Notify all applications to register */
1230 ret = notify_ust_apps(1);
1231 if (ret < 0) {
1232 ERR("Failed to notify applications or create the wait shared memory.\n"
1233 "Execution continues but there might be problem for already\n"
1234 "running applications that wishes to register.");
1235 }
1236
1237 while (1) {
1238 DBG("Accepting application registration");
1239
1240 nb_fd = LTTNG_POLL_GETNB(&events);
1241
1242 /* Inifinite blocking call, waiting for transmission */
1243 ret = lttng_poll_wait(&events, -1);
1244 if (ret < 0) {
1245 goto error;
1246 }
1247
1248 for (i = 0; i < nb_fd; i++) {
1249 /* Fetch once the poll data */
1250 revents = LTTNG_POLL_GETEV(&events, i);
1251 pollfd = LTTNG_POLL_GETFD(&events, i);
1252
1253 /* Thread quit pipe has been closed. Killing thread. */
1254 ret = check_thread_quit_pipe(pollfd, revents);
1255 if (ret) {
1256 goto error;
1257 }
1258
1259 /* Event on the registration socket */
1260 if (pollfd == apps_sock) {
1261 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1262 ERR("Register apps socket poll error");
1263 goto error;
1264 } else if (revents & LPOLLIN) {
1265 sock = lttcomm_accept_unix_sock(apps_sock);
1266 if (sock < 0) {
1267 goto error;
1268 }
1269
1270 /* Create UST registration command for enqueuing */
1271 ust_cmd = zmalloc(sizeof(struct ust_command));
1272 if (ust_cmd == NULL) {
1273 perror("ust command zmalloc");
1274 goto error;
1275 }
1276
1277 /*
1278 * Using message-based transmissions to ensure we don't
1279 * have to deal with partially received messages.
1280 */
1281 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1282 sizeof(struct ust_register_msg));
1283 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1284 if (ret < 0) {
1285 perror("lttcomm_recv_unix_sock register apps");
1286 } else {
1287 ERR("Wrong size received on apps register");
1288 }
1289 free(ust_cmd);
1290 close(sock);
1291 continue;
1292 }
1293
1294 ust_cmd->sock = sock;
1295
1296 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1297 " gid:%d sock:%d name:%s (version %d.%d)",
1298 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1299 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1300 ust_cmd->sock, ust_cmd->reg_msg.name,
1301 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1302
1303 /*
1304 * Lock free enqueue the registration request. The red pill
1305 * has been taken! This apps will be part of the *system*.
1306 */
1307 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1308
1309 /*
1310 * Wake the registration queue futex. Implicit memory
1311 * barrier with the exchange in cds_wfq_enqueue.
1312 */
1313 futex_nto1_wake(&ust_cmd_queue.futex);
1314 }
1315 }
1316 }
1317 }
1318
1319 error:
1320 DBG("UST Registration thread dying");
1321
1322 /* Notify that the registration thread is gone */
1323 notify_ust_apps(0);
1324
1325 close(apps_sock);
1326 close(sock);
1327 unlink(apps_unix_sock_path);
1328
1329 lttng_poll_clean(&events);
1330
1331 return NULL;
1332 }
1333
1334 /*
1335 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1336 * exec or it will fails.
1337 */
1338 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1339 {
1340 int ret;
1341 struct timespec timeout;
1342
1343 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1344 timeout.tv_nsec = 0;
1345
1346 /* Setup semaphore */
1347 ret = sem_init(&consumer_data->sem, 0, 0);
1348 if (ret < 0) {
1349 PERROR("sem_init consumer semaphore");
1350 goto error;
1351 }
1352
1353 ret = pthread_create(&consumer_data->thread, NULL,
1354 thread_manage_consumer, consumer_data);
1355 if (ret != 0) {
1356 PERROR("pthread_create consumer");
1357 ret = -1;
1358 goto error;
1359 }
1360
1361 /* Get time for sem_timedwait absolute timeout */
1362 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1363 if (ret < 0) {
1364 PERROR("clock_gettime spawn consumer");
1365 /* Infinite wait for the kconsumerd thread to be ready */
1366 ret = sem_wait(&consumer_data->sem);
1367 } else {
1368 /* Normal timeout if the gettime was successful */
1369 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1370 ret = sem_timedwait(&consumer_data->sem, &timeout);
1371 }
1372
1373 if (ret < 0) {
1374 if (errno == ETIMEDOUT) {
1375 /*
1376 * Call has timed out so we kill the kconsumerd_thread and return
1377 * an error.
1378 */
1379 ERR("The consumer thread was never ready. Killing it");
1380 ret = pthread_cancel(consumer_data->thread);
1381 if (ret < 0) {
1382 PERROR("pthread_cancel consumer thread");
1383 }
1384 } else {
1385 PERROR("semaphore wait failed consumer thread");
1386 }
1387 goto error;
1388 }
1389
1390 pthread_mutex_lock(&consumer_data->pid_mutex);
1391 if (consumer_data->pid == 0) {
1392 ERR("Kconsumerd did not start");
1393 pthread_mutex_unlock(&consumer_data->pid_mutex);
1394 goto error;
1395 }
1396 pthread_mutex_unlock(&consumer_data->pid_mutex);
1397
1398 return 0;
1399
1400 error:
1401 return ret;
1402 }
1403
1404 /*
1405 * Join consumer thread
1406 */
1407 static int join_consumer_thread(struct consumer_data *consumer_data)
1408 {
1409 void *status;
1410 int ret;
1411
1412 if (consumer_data->pid != 0) {
1413 ret = kill(consumer_data->pid, SIGTERM);
1414 if (ret) {
1415 ERR("Error killing consumer daemon");
1416 return ret;
1417 }
1418 return pthread_join(consumer_data->thread, &status);
1419 } else {
1420 return 0;
1421 }
1422 }
1423
1424 /*
1425 * Fork and exec a consumer daemon (consumerd).
1426 *
1427 * Return pid if successful else -1.
1428 */
1429 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1430 {
1431 int ret;
1432 pid_t pid;
1433 const char *verbosity;
1434
1435 DBG("Spawning consumerd");
1436
1437 pid = fork();
1438 if (pid == 0) {
1439 /*
1440 * Exec consumerd.
1441 */
1442 if (opt_verbose > 1 || opt_verbose_consumer) {
1443 verbosity = "--verbose";
1444 } else {
1445 verbosity = "--quiet";
1446 }
1447 switch (consumer_data->type) {
1448 case LTTNG_CONSUMER_KERNEL:
1449 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1450 "lttng-consumerd", verbosity, "-k", NULL);
1451 break;
1452 case LTTNG_CONSUMER_UST:
1453 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1454 "lttng-consumerd", verbosity, "-u", NULL);
1455 break;
1456 default:
1457 perror("unknown consumer type");
1458 exit(EXIT_FAILURE);
1459 }
1460 if (errno != 0) {
1461 perror("kernel start consumer exec");
1462 }
1463 exit(EXIT_FAILURE);
1464 } else if (pid > 0) {
1465 ret = pid;
1466 } else {
1467 perror("start consumer fork");
1468 ret = -errno;
1469 }
1470 return ret;
1471 }
1472
1473 /*
1474 * Spawn the consumerd daemon and session daemon thread.
1475 */
1476 static int start_consumerd(struct consumer_data *consumer_data)
1477 {
1478 int ret;
1479
1480 pthread_mutex_lock(&consumer_data->pid_mutex);
1481 if (consumer_data->pid != 0) {
1482 pthread_mutex_unlock(&consumer_data->pid_mutex);
1483 goto end;
1484 }
1485
1486 ret = spawn_consumerd(consumer_data);
1487 if (ret < 0) {
1488 ERR("Spawning consumerd failed");
1489 pthread_mutex_unlock(&consumer_data->pid_mutex);
1490 goto error;
1491 }
1492
1493 /* Setting up the consumer_data pid */
1494 consumer_data->pid = ret;
1495 DBG2("Consumer pid %d", consumer_data->pid);
1496 pthread_mutex_unlock(&consumer_data->pid_mutex);
1497
1498 DBG2("Spawning consumer control thread");
1499 ret = spawn_consumer_thread(consumer_data);
1500 if (ret < 0) {
1501 ERR("Fatal error spawning consumer control thread");
1502 goto error;
1503 }
1504
1505 end:
1506 return 0;
1507
1508 error:
1509 return ret;
1510 }
1511
1512 /*
1513 * modprobe_kernel_modules
1514 */
1515 static int modprobe_kernel_modules(void)
1516 {
1517 int ret = 0, i;
1518 char modprobe[256];
1519
1520 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1521 ret = snprintf(modprobe, sizeof(modprobe),
1522 "/sbin/modprobe %s%s",
1523 kernel_modules_list[i].required ? "" : "-q ",
1524 kernel_modules_list[i].name);
1525 if (ret < 0) {
1526 perror("snprintf modprobe");
1527 goto error;
1528 }
1529 modprobe[sizeof(modprobe) - 1] = '\0';
1530 ret = system(modprobe);
1531 if (ret == -1) {
1532 ERR("Unable to launch modprobe for module %s",
1533 kernel_modules_list[i].name);
1534 } else if (kernel_modules_list[i].required
1535 && WEXITSTATUS(ret) != 0) {
1536 ERR("Unable to load module %s",
1537 kernel_modules_list[i].name);
1538 } else {
1539 DBG("Modprobe successfully %s",
1540 kernel_modules_list[i].name);
1541 }
1542 }
1543
1544 error:
1545 return ret;
1546 }
1547
1548 /*
1549 * mount_debugfs
1550 */
1551 static int mount_debugfs(char *path)
1552 {
1553 int ret;
1554 char *type = "debugfs";
1555
1556 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1557 if (ret < 0) {
1558 PERROR("Cannot create debugfs path");
1559 goto error;
1560 }
1561
1562 ret = mount(type, path, type, 0, NULL);
1563 if (ret < 0) {
1564 PERROR("Cannot mount debugfs");
1565 goto error;
1566 }
1567
1568 DBG("Mounted debugfs successfully at %s", path);
1569
1570 error:
1571 return ret;
1572 }
1573
1574 /*
1575 * Setup necessary data for kernel tracer action.
1576 */
1577 static void init_kernel_tracer(void)
1578 {
1579 int ret;
1580 char *proc_mounts = "/proc/mounts";
1581 char line[256];
1582 char *debugfs_path = NULL, *lttng_path = NULL;
1583 FILE *fp;
1584
1585 /* Detect debugfs */
1586 fp = fopen(proc_mounts, "r");
1587 if (fp == NULL) {
1588 ERR("Unable to probe %s", proc_mounts);
1589 goto error;
1590 }
1591
1592 while (fgets(line, sizeof(line), fp) != NULL) {
1593 if (strstr(line, "debugfs") != NULL) {
1594 /* Remove first string */
1595 strtok(line, " ");
1596 /* Dup string here so we can reuse line later on */
1597 debugfs_path = strdup(strtok(NULL, " "));
1598 DBG("Got debugfs path : %s", debugfs_path);
1599 break;
1600 }
1601 }
1602
1603 fclose(fp);
1604
1605 /* Mount debugfs if needded */
1606 if (debugfs_path == NULL) {
1607 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1608 if (ret < 0) {
1609 perror("asprintf debugfs path");
1610 goto error;
1611 }
1612 ret = mount_debugfs(debugfs_path);
1613 if (ret < 0) {
1614 perror("Cannot mount debugfs");
1615 goto error;
1616 }
1617 }
1618
1619 /* Modprobe lttng kernel modules */
1620 ret = modprobe_kernel_modules();
1621 if (ret < 0) {
1622 goto error;
1623 }
1624
1625 /* Setup lttng kernel path */
1626 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1627 if (ret < 0) {
1628 perror("asprintf lttng path");
1629 goto error;
1630 }
1631
1632 /* Open debugfs lttng */
1633 kernel_tracer_fd = open(lttng_path, O_RDWR);
1634 if (kernel_tracer_fd < 0) {
1635 DBG("Failed to open %s", lttng_path);
1636 goto error;
1637 }
1638
1639 free(lttng_path);
1640 free(debugfs_path);
1641 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1642 return;
1643
1644 error:
1645 if (lttng_path) {
1646 free(lttng_path);
1647 }
1648 if (debugfs_path) {
1649 free(debugfs_path);
1650 }
1651 WARN("No kernel tracer available");
1652 kernel_tracer_fd = 0;
1653 return;
1654 }
1655
1656 /*
1657 * Init tracing by creating trace directory and sending fds kernel consumer.
1658 */
1659 static int init_kernel_tracing(struct ltt_kernel_session *session)
1660 {
1661 int ret = 0;
1662
1663 if (session->consumer_fds_sent == 0) {
1664 /*
1665 * Assign default kernel consumer socket if no consumer assigned to the
1666 * kernel session. At this point, it's NOT suppose to be 0 but this is
1667 * an extra security check.
1668 */
1669 if (session->consumer_fd == 0) {
1670 session->consumer_fd = kconsumer_data.cmd_sock;
1671 }
1672
1673 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1674 if (ret < 0) {
1675 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1676 goto error;
1677 }
1678
1679 session->consumer_fds_sent = 1;
1680 }
1681
1682 error:
1683 return ret;
1684 }
1685
1686 /*
1687 * Create an UST session and add it to the session ust list.
1688 */
1689 static int create_ust_session(struct ltt_session *session,
1690 struct lttng_domain *domain)
1691 {
1692 int ret;
1693 unsigned int uid;
1694 struct ltt_ust_session *lus = NULL;
1695
1696 switch (domain->type) {
1697 case LTTNG_DOMAIN_UST:
1698 break;
1699 default:
1700 ret = LTTCOMM_UNKNOWN_DOMAIN;
1701 goto error;
1702 }
1703
1704 DBG("Creating UST session");
1705
1706 session_lock_list();
1707 uid = session_list_ptr->count;
1708 session_unlock_list();
1709
1710 lus = trace_ust_create_session(session->path, uid, domain);
1711 if (lus == NULL) {
1712 ret = LTTCOMM_UST_SESS_FAIL;
1713 goto error;
1714 }
1715
1716 ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1717 geteuid(), allowed_group());
1718 if (ret < 0) {
1719 if (ret != -EEXIST) {
1720 ERR("Trace directory creation error");
1721 ret = LTTCOMM_UST_SESS_FAIL;
1722 goto error;
1723 }
1724 }
1725
1726 /* The domain type dictate different actions on session creation */
1727 switch (domain->type) {
1728 case LTTNG_DOMAIN_UST:
1729 /* No ustctl for the global UST domain */
1730 break;
1731 default:
1732 ERR("Unknown UST domain on create session %d", domain->type);
1733 goto error;
1734 }
1735 session->ust_session = lus;
1736
1737 return LTTCOMM_OK;
1738
1739 error:
1740 free(lus);
1741 return ret;
1742 }
1743
1744 /*
1745 * Create a kernel tracer session then create the default channel.
1746 */
1747 static int create_kernel_session(struct ltt_session *session)
1748 {
1749 int ret;
1750
1751 DBG("Creating kernel session");
1752
1753 ret = kernel_create_session(session, kernel_tracer_fd);
1754 if (ret < 0) {
1755 ret = LTTCOMM_KERN_SESS_FAIL;
1756 goto error;
1757 }
1758
1759 /* Set kernel consumer socket fd */
1760 if (kconsumer_data.cmd_sock) {
1761 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1762 }
1763
1764 ret = mkdir_recursive(session->kernel_session->trace_path,
1765 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1766 if (ret < 0) {
1767 if (ret != -EEXIST) {
1768 ERR("Trace directory creation error");
1769 goto error;
1770 }
1771 }
1772
1773 error:
1774 return ret;
1775 }
1776
1777 /*
1778 * Using the session list, filled a lttng_session array to send back to the
1779 * client for session listing.
1780 *
1781 * The session list lock MUST be acquired before calling this function. Use
1782 * session_lock_list() and session_unlock_list().
1783 */
1784 static void list_lttng_sessions(struct lttng_session *sessions)
1785 {
1786 int i = 0;
1787 struct ltt_session *session;
1788
1789 DBG("Getting all available session");
1790 /*
1791 * Iterate over session list and append data after the control struct in
1792 * the buffer.
1793 */
1794 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1795 strncpy(sessions[i].path, session->path, PATH_MAX);
1796 sessions[i].path[PATH_MAX - 1] = '\0';
1797 strncpy(sessions[i].name, session->name, NAME_MAX);
1798 sessions[i].name[NAME_MAX - 1] = '\0';
1799 sessions[i].enabled = session->enabled;
1800 i++;
1801 }
1802 }
1803
1804 /*
1805 * Fill lttng_channel array of all channels.
1806 */
1807 static void list_lttng_channels(int domain, struct ltt_session *session,
1808 struct lttng_channel *channels)
1809 {
1810 int i = 0;
1811 struct ltt_kernel_channel *kchan;
1812
1813 DBG("Listing channels for session %s", session->name);
1814
1815 switch (domain) {
1816 case LTTNG_DOMAIN_KERNEL:
1817 /* Kernel channels */
1818 if (session->kernel_session != NULL) {
1819 cds_list_for_each_entry(kchan,
1820 &session->kernel_session->channel_list.head, list) {
1821 /* Copy lttng_channel struct to array */
1822 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1823 channels[i].enabled = kchan->enabled;
1824 i++;
1825 }
1826 }
1827 break;
1828 case LTTNG_DOMAIN_UST:
1829 {
1830 struct cds_lfht_iter iter;
1831 struct ltt_ust_channel *uchan;
1832
1833 cds_lfht_for_each_entry(session->ust_session->domain_global.channels,
1834 &iter, uchan, node) {
1835 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
1836 channels[i].attr.overwrite = uchan->attr.overwrite;
1837 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
1838 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
1839 channels[i].attr.switch_timer_interval =
1840 uchan->attr.switch_timer_interval;
1841 channels[i].attr.read_timer_interval =
1842 uchan->attr.read_timer_interval;
1843 channels[i].attr.output = uchan->attr.output;
1844 }
1845 break;
1846 }
1847 default:
1848 break;
1849 }
1850 }
1851
1852 /*
1853 * Create a list of ust global domain events.
1854 */
1855 static int list_lttng_ust_global_events(char *channel_name,
1856 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
1857 {
1858 int i = 0, ret = 0;
1859 unsigned int nb_event = 0;
1860 struct cds_lfht_iter iter;
1861 struct ltt_ust_channel *uchan;
1862 struct ltt_ust_event *uevent;
1863 struct lttng_event *tmp;
1864
1865 DBG("Listing UST global events for channel %s", channel_name);
1866
1867 rcu_read_lock();
1868
1869 /* Count events in all channels */
1870 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1871 nb_event += hashtable_get_count(uchan->events);
1872 }
1873
1874 if (nb_event == 0) {
1875 ret = nb_event;
1876 goto error;
1877 }
1878
1879 DBG3("Listing UST global %d events", nb_event);
1880
1881 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
1882 if (tmp == NULL) {
1883 ret = -LTTCOMM_FATAL;
1884 goto error;
1885 }
1886
1887 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1888 cds_lfht_for_each_entry(uchan->events, &iter, uevent, node) {
1889 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
1890 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1891 tmp[i].enabled = uevent->enabled;
1892 switch (uevent->attr.instrumentation) {
1893 case LTTNG_UST_TRACEPOINT:
1894 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
1895 break;
1896 case LTTNG_UST_PROBE:
1897 tmp[i].type = LTTNG_EVENT_PROBE;
1898 break;
1899 case LTTNG_UST_FUNCTION:
1900 tmp[i].type = LTTNG_EVENT_FUNCTION;
1901 break;
1902 }
1903 i++;
1904 }
1905 }
1906
1907 ret = nb_event;
1908 *events = tmp;
1909
1910 error:
1911 rcu_read_unlock();
1912 return ret;
1913 }
1914
1915 /*
1916 * Fill lttng_event array of all kernel events in the channel.
1917 */
1918 static int list_lttng_kernel_events(char *channel_name,
1919 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
1920 {
1921 int i = 0, ret;
1922 unsigned int nb_event;
1923 struct ltt_kernel_event *event;
1924 struct ltt_kernel_channel *kchan;
1925
1926 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
1927 if (kchan == NULL) {
1928 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1929 goto error;
1930 }
1931
1932 nb_event = kchan->event_count;
1933
1934 DBG("Listing events for channel %s", kchan->channel->name);
1935
1936 if (nb_event == 0) {
1937 ret = nb_event;
1938 goto error;
1939 }
1940
1941 *events = zmalloc(nb_event * sizeof(struct lttng_event));
1942 if (*events == NULL) {
1943 ret = LTTCOMM_FATAL;
1944 goto error;
1945 }
1946
1947 /* Kernel channels */
1948 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1949 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1950 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1951 (*events)[i].enabled = event->enabled;
1952 switch (event->event->instrumentation) {
1953 case LTTNG_KERNEL_TRACEPOINT:
1954 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
1955 break;
1956 case LTTNG_KERNEL_KPROBE:
1957 case LTTNG_KERNEL_KRETPROBE:
1958 (*events)[i].type = LTTNG_EVENT_PROBE;
1959 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
1960 sizeof(struct lttng_kernel_kprobe));
1961 break;
1962 case LTTNG_KERNEL_FUNCTION:
1963 (*events)[i].type = LTTNG_EVENT_FUNCTION;
1964 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
1965 sizeof(struct lttng_kernel_function));
1966 break;
1967 case LTTNG_KERNEL_NOOP:
1968 (*events)[i].type = LTTNG_EVENT_NOOP;
1969 break;
1970 case LTTNG_KERNEL_SYSCALL:
1971 (*events)[i].type = LTTNG_EVENT_SYSCALL;
1972 break;
1973 case LTTNG_KERNEL_ALL:
1974 assert(0);
1975 break;
1976 }
1977 i++;
1978 }
1979
1980 return nb_event;
1981
1982 error:
1983 return ret;
1984 }
1985
1986 /*
1987 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1988 */
1989 static int cmd_disable_channel(struct ltt_session *session,
1990 int domain, char *channel_name)
1991 {
1992 int ret;
1993
1994 switch (domain) {
1995 case LTTNG_DOMAIN_KERNEL:
1996 ret = channel_kernel_disable(session->kernel_session,
1997 channel_name);
1998 if (ret != LTTCOMM_OK) {
1999 goto error;
2000 }
2001
2002 kernel_wait_quiescent(kernel_tracer_fd);
2003 break;
2004 case LTTNG_DOMAIN_UST_PID:
2005 break;
2006 default:
2007 ret = LTTCOMM_UNKNOWN_DOMAIN;
2008 goto error;
2009 }
2010
2011 ret = LTTCOMM_OK;
2012
2013 error:
2014 return ret;
2015 }
2016
2017 /*
2018 * Copy channel from attributes and set it in the application channel list.
2019 */
2020 /*
2021 static int copy_ust_channel_to_app(struct ltt_ust_session *usess,
2022 struct lttng_channel *attr, struct ust_app *app)
2023 {
2024 int ret;
2025 struct ltt_ust_channel *uchan, *new_chan;
2026
2027 uchan = trace_ust_get_channel_by_key(usess->channels, attr->name);
2028 if (uchan == NULL) {
2029 ret = LTTCOMM_FATAL;
2030 goto error;
2031 }
2032
2033 new_chan = trace_ust_create_channel(attr, usess->path);
2034 if (new_chan == NULL) {
2035 PERROR("malloc ltt_ust_channel");
2036 ret = LTTCOMM_FATAL;
2037 goto error;
2038 }
2039
2040 ret = channel_ust_copy(new_chan, uchan);
2041 if (ret < 0) {
2042 ret = LTTCOMM_FATAL;
2043 goto error;
2044 }
2045
2046 error:
2047 return ret;
2048 }
2049 */
2050
2051 /*
2052 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2053 */
2054 static int cmd_enable_channel(struct ltt_session *session,
2055 struct lttng_domain *domain, struct lttng_channel *attr)
2056 {
2057 int ret;
2058 struct ltt_ust_session *usess = session->ust_session;
2059
2060 DBG("Enabling channel %s for session %s", attr->name, session->name);
2061
2062 switch (domain->type) {
2063 case LTTNG_DOMAIN_KERNEL:
2064 {
2065 struct ltt_kernel_channel *kchan;
2066
2067 kchan = trace_kernel_get_channel_by_name(attr->name,
2068 session->kernel_session);
2069 if (kchan == NULL) {
2070 ret = channel_kernel_create(session->kernel_session,
2071 attr, kernel_poll_pipe[1]);
2072 } else {
2073 ret = channel_kernel_enable(session->kernel_session, kchan);
2074 }
2075
2076 if (ret != LTTCOMM_OK) {
2077 goto error;
2078 }
2079
2080 kernel_wait_quiescent(kernel_tracer_fd);
2081 break;
2082 }
2083 case LTTNG_DOMAIN_UST:
2084 {
2085 struct ltt_ust_channel *uchan;
2086
2087 DBG2("Enabling channel for LTTNG_DOMAIN_UST");
2088
2089 /* Get channel in global UST domain HT */
2090 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2091 attr->name);
2092 if (uchan == NULL) {
2093 uchan = trace_ust_create_channel(attr, usess->pathname);
2094 if (uchan == NULL) {
2095 ret = LTTCOMM_UST_CHAN_FAIL;
2096 goto error;
2097 }
2098
2099 rcu_read_lock();
2100 hashtable_add_unique(usess->domain_global.channels, &uchan->node);
2101 rcu_read_unlock();
2102 DBG2("UST channel %s added to global domain HT", attr->name);
2103 } else {
2104 ret = LTTCOMM_UST_CHAN_EXIST;
2105 goto error;
2106 }
2107
2108 /* Add channel to all registered applications */
2109 ret = ust_app_create_channel_all(usess, uchan);
2110 if (ret != 0) {
2111 goto error;
2112 }
2113
2114 uchan->enabled = 1;
2115
2116 break;
2117 }
2118 case LTTNG_DOMAIN_UST_PID:
2119 {
2120 /*
2121 int sock;
2122 struct ltt_ust_channel *uchan;
2123 struct ltt_ust_session *usess;
2124 struct ust_app *app;
2125
2126 usess = trace_ust_get_session_by_pid(&session->ust_session_list,
2127 domain->attr.pid);
2128 if (usess == NULL) {
2129 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2130 goto error;
2131 }
2132
2133 app = ust_app_get_by_pid(domain->attr.pid);
2134 if (app == NULL) {
2135 ret = LTTCOMM_APP_NOT_FOUND;
2136 goto error;
2137 }
2138 sock = app->sock;
2139
2140 uchan = trace_ust_get_channel_by_name(attr->name, usess);
2141 if (uchan == NULL) {
2142 ret = channel_ust_create(usess, attr, sock);
2143 } else {
2144 ret = channel_ust_enable(usess, uchan, sock);
2145 }
2146
2147 if (ret != LTTCOMM_OK) {
2148 goto error;
2149 }
2150
2151 ret = copy_ust_channel_to_app(usess, attr, app);
2152 if (ret != LTTCOMM_OK) {
2153 goto error;
2154 }
2155
2156 DBG("UST channel %s created for app sock %d with pid %d",
2157 attr->name, app->sock, domain->attr.pid);
2158 */
2159 ret = LTTCOMM_NOT_IMPLEMENTED;
2160 goto error;
2161 }
2162 default:
2163 ret = LTTCOMM_UNKNOWN_DOMAIN;
2164 goto error;
2165 }
2166
2167 ret = LTTCOMM_OK;
2168
2169 error:
2170 return ret;
2171 }
2172
2173 /*
2174 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2175 */
2176 static int cmd_disable_event(struct ltt_session *session, int domain,
2177 char *channel_name, char *event_name)
2178 {
2179 int ret;
2180
2181 switch (domain) {
2182 case LTTNG_DOMAIN_KERNEL:
2183 {
2184 struct ltt_kernel_channel *kchan;
2185
2186 kchan = trace_kernel_get_channel_by_name(channel_name,
2187 session->kernel_session);
2188 if (kchan == NULL) {
2189 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2190 goto error;
2191 }
2192
2193 ret = event_kernel_disable_tracepoint(session->kernel_session, kchan, event_name);
2194 if (ret != LTTCOMM_OK) {
2195 goto error;
2196 }
2197
2198 kernel_wait_quiescent(kernel_tracer_fd);
2199 break;
2200 }
2201 case LTTNG_DOMAIN_UST:
2202 case LTTNG_DOMAIN_UST_EXEC_NAME:
2203 case LTTNG_DOMAIN_UST_PID:
2204 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2205 default:
2206 /* TODO: Other UST domains */
2207 ret = LTTCOMM_NOT_IMPLEMENTED;
2208 goto error;
2209 }
2210
2211 ret = LTTCOMM_OK;
2212
2213 error:
2214 return ret;
2215 }
2216
2217 /*
2218 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2219 */
2220 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2221 char *channel_name)
2222 {
2223 int ret;
2224 struct ltt_kernel_channel *kchan;
2225
2226 switch (domain) {
2227 case LTTNG_DOMAIN_KERNEL:
2228 kchan = trace_kernel_get_channel_by_name(channel_name,
2229 session->kernel_session);
2230 if (kchan == NULL) {
2231 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2232 goto error;
2233 }
2234
2235 ret = event_kernel_disable_all(session->kernel_session, kchan);
2236 if (ret != LTTCOMM_OK) {
2237 goto error;
2238 }
2239
2240 kernel_wait_quiescent(kernel_tracer_fd);
2241 break;
2242 default:
2243 /* TODO: Userspace tracing */
2244 ret = LTTCOMM_NOT_IMPLEMENTED;
2245 goto error;
2246 }
2247
2248 ret = LTTCOMM_OK;
2249
2250 error:
2251 return ret;
2252 }
2253
2254 /*
2255 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2256 */
2257 static int cmd_add_context(struct ltt_session *session, int domain,
2258 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2259 {
2260 int ret;
2261
2262 switch (domain) {
2263 case LTTNG_DOMAIN_KERNEL:
2264 /* Add kernel context to kernel tracer */
2265 ret = context_kernel_add(session->kernel_session, ctx,
2266 event_name, channel_name);
2267 if (ret != LTTCOMM_OK) {
2268 goto error;
2269 }
2270 break;
2271 case LTTNG_DOMAIN_UST:
2272 {
2273 /*
2274 struct ltt_ust_session *usess;
2275
2276 cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2277 ret = context_ust_add(usess, ctx,
2278 event_name, channel_name, domain);
2279 if (ret != LTTCOMM_OK) {
2280 goto error;
2281 }
2282 }
2283 break;
2284 */
2285 }
2286 default:
2287 /* TODO: UST other domains */
2288 ret = LTTCOMM_NOT_IMPLEMENTED;
2289 goto error;
2290 }
2291
2292 ret = LTTCOMM_OK;
2293
2294 error:
2295 return ret;
2296 }
2297
2298 /*
2299 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2300 */
2301 static int cmd_enable_event(struct ltt_session *session, int domain,
2302 char *channel_name, struct lttng_event *event)
2303 {
2304 int ret;
2305 struct lttng_channel *attr;
2306 struct ltt_ust_session *usess = session->ust_session;
2307
2308 switch (domain) {
2309 case LTTNG_DOMAIN_KERNEL:
2310 {
2311 struct ltt_kernel_channel *kchan;
2312
2313 kchan = trace_kernel_get_channel_by_name(channel_name,
2314 session->kernel_session);
2315 if (kchan == NULL) {
2316 attr = channel_new_default_attr(domain);
2317 if (attr == NULL) {
2318 ret = LTTCOMM_FATAL;
2319 goto error;
2320 }
2321 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2322
2323 /* This call will notify the kernel thread */
2324 ret = channel_kernel_create(session->kernel_session,
2325 attr, kernel_poll_pipe[1]);
2326 if (ret != LTTCOMM_OK) {
2327 goto error;
2328 }
2329 }
2330
2331 /* Get the newly created kernel channel pointer */
2332 kchan = trace_kernel_get_channel_by_name(channel_name,
2333 session->kernel_session);
2334 if (kchan == NULL) {
2335 /* This sould not happen... */
2336 ret = LTTCOMM_FATAL;
2337 goto error;
2338 }
2339
2340 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2341 event);
2342 if (ret != LTTCOMM_OK) {
2343 goto error;
2344 }
2345
2346 kernel_wait_quiescent(kernel_tracer_fd);
2347 break;
2348 }
2349 case LTTNG_DOMAIN_UST:
2350 {
2351 struct ltt_ust_channel *uchan;
2352 struct ltt_ust_event *uevent;
2353
2354 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2355 channel_name);
2356 if (uchan == NULL) {
2357 /* TODO: Create default channel */
2358 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2359 goto error;
2360 }
2361
2362 uevent = trace_ust_find_event_by_name(uchan->events, event->name);
2363 if (uevent == NULL) {
2364 uevent = trace_ust_create_event(event);
2365 if (uevent == NULL) {
2366 ret = LTTCOMM_FATAL;
2367 goto error;
2368 }
2369
2370 }
2371
2372 ret = ust_app_create_event_all(usess, uchan, uevent);
2373 if (ret < 0) {
2374 ret = LTTCOMM_UST_ENABLE_FAIL;
2375 goto error;
2376 }
2377
2378 /* Add ltt ust event to channel */
2379 rcu_read_lock();
2380 hashtable_add_unique(uchan->events, &uevent->node);
2381 rcu_read_unlock();
2382
2383 uevent->enabled = 1;
2384
2385 DBG3("UST ltt event %s added to channel %s", uevent->attr.name,
2386 uchan->name);
2387 break;
2388 }
2389 case LTTNG_DOMAIN_UST_EXEC_NAME:
2390 case LTTNG_DOMAIN_UST_PID:
2391 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2392 default:
2393 ret = LTTCOMM_NOT_IMPLEMENTED;
2394 goto error;
2395 }
2396
2397 ret = LTTCOMM_OK;
2398
2399 error:
2400 return ret;
2401 }
2402
2403 /*
2404 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2405 */
2406 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2407 char *channel_name, int event_type)
2408 {
2409 int ret;
2410 struct ltt_kernel_channel *kchan;
2411
2412 switch (domain) {
2413 case LTTNG_DOMAIN_KERNEL:
2414 kchan = trace_kernel_get_channel_by_name(channel_name,
2415 session->kernel_session);
2416 if (kchan == NULL) {
2417 /* This call will notify the kernel thread */
2418 ret = channel_kernel_create(session->kernel_session, NULL,
2419 kernel_poll_pipe[1]);
2420 if (ret != LTTCOMM_OK) {
2421 goto error;
2422 }
2423 }
2424
2425 /* Get the newly created kernel channel pointer */
2426 kchan = trace_kernel_get_channel_by_name(channel_name,
2427 session->kernel_session);
2428 if (kchan == NULL) {
2429 /* This sould not happen... */
2430 ret = LTTCOMM_FATAL;
2431 goto error;
2432 }
2433
2434 switch (event_type) {
2435 case LTTNG_KERNEL_SYSCALL:
2436 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2437 kchan, kernel_tracer_fd);
2438 break;
2439 case LTTNG_KERNEL_TRACEPOINT:
2440 /*
2441 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2442 * events already registered to the channel.
2443 */
2444 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2445 kchan, kernel_tracer_fd);
2446 break;
2447 case LTTNG_KERNEL_ALL:
2448 /* Enable syscalls and tracepoints */
2449 ret = event_kernel_enable_all(session->kernel_session,
2450 kchan, kernel_tracer_fd);
2451 break;
2452 default:
2453 ret = LTTCOMM_KERN_ENABLE_FAIL;
2454 goto error;
2455 }
2456 if (ret != LTTCOMM_OK) {
2457 goto error;
2458 }
2459
2460 kernel_wait_quiescent(kernel_tracer_fd);
2461 break;
2462 default:
2463 /* TODO: Userspace tracing */
2464 ret = LTTCOMM_NOT_IMPLEMENTED;
2465 goto error;
2466 }
2467
2468 ret = LTTCOMM_OK;
2469
2470 error:
2471 return ret;
2472 }
2473
2474 /*
2475 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2476 */
2477 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2478 {
2479 int ret;
2480 ssize_t nb_events = 0;
2481
2482 switch (domain) {
2483 case LTTNG_DOMAIN_KERNEL:
2484 nb_events = kernel_list_events(kernel_tracer_fd, events);
2485 if (nb_events < 0) {
2486 ret = LTTCOMM_KERN_LIST_FAIL;
2487 goto error;
2488 }
2489 break;
2490 case LTTNG_DOMAIN_UST:
2491 nb_events = ust_app_list_events(events);
2492 if (nb_events < 0) {
2493 ret = LTTCOMM_UST_LIST_FAIL;
2494 goto error;
2495 }
2496 break;
2497 default:
2498 ret = LTTCOMM_NOT_IMPLEMENTED;
2499 goto error;
2500 }
2501
2502 return nb_events;
2503
2504 error:
2505 /* Return negative value to differentiate return code */
2506 return -ret;
2507 }
2508
2509 /*
2510 * Command LTTNG_START_TRACE processed by the client thread.
2511 */
2512 static int cmd_start_trace(struct ltt_session *session)
2513 {
2514 int ret;
2515 struct ltt_kernel_session *ksession;
2516 struct ltt_ust_session *usess;
2517
2518 /* Short cut */
2519 ksession = session->kernel_session;
2520 usess = session->ust_session;
2521
2522 if (session->enabled)
2523 return LTTCOMM_UST_START_FAIL;
2524 session->enabled = 1;
2525
2526 /* Kernel tracing */
2527 if (ksession != NULL) {
2528 struct ltt_kernel_channel *kchan;
2529
2530 /* Open kernel metadata */
2531 if (ksession->metadata == NULL) {
2532 ret = kernel_open_metadata(ksession, ksession->trace_path);
2533 if (ret < 0) {
2534 ret = LTTCOMM_KERN_META_FAIL;
2535 goto error;
2536 }
2537 }
2538
2539 /* Open kernel metadata stream */
2540 if (ksession->metadata_stream_fd == 0) {
2541 ret = kernel_open_metadata_stream(ksession);
2542 if (ret < 0) {
2543 ERR("Kernel create metadata stream failed");
2544 ret = LTTCOMM_KERN_STREAM_FAIL;
2545 goto error;
2546 }
2547 }
2548
2549 /* For each channel */
2550 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2551 if (kchan->stream_count == 0) {
2552 ret = kernel_open_channel_stream(kchan);
2553 if (ret < 0) {
2554 ret = LTTCOMM_KERN_STREAM_FAIL;
2555 goto error;
2556 }
2557 /* Update the stream global counter */
2558 ksession->stream_count_global += ret;
2559 }
2560 }
2561
2562 /* Setup kernel consumer socket and send fds to it */
2563 ret = init_kernel_tracing(ksession);
2564 if (ret < 0) {
2565 ret = LTTCOMM_KERN_START_FAIL;
2566 goto error;
2567 }
2568
2569 /* This start the kernel tracing */
2570 ret = kernel_start_session(ksession);
2571 if (ret < 0) {
2572 ret = LTTCOMM_KERN_START_FAIL;
2573 goto error;
2574 }
2575
2576 /* Quiescent wait after starting trace */
2577 kernel_wait_quiescent(kernel_tracer_fd);
2578 }
2579
2580 /* Flag session that trace should start automatically */
2581 if (usess) {
2582 usess->start_trace = 1;
2583
2584 ret = ust_app_start_trace_all(usess);
2585 if (ret < 0) {
2586 ret = LTTCOMM_UST_START_FAIL;
2587 goto error;
2588 }
2589 }
2590
2591 ret = LTTCOMM_OK;
2592
2593 error:
2594 return ret;
2595 }
2596
2597 /*
2598 * Command LTTNG_STOP_TRACE processed by the client thread.
2599 */
2600 static int cmd_stop_trace(struct ltt_session *session)
2601 {
2602 int ret;
2603 struct ltt_kernel_channel *kchan;
2604 struct ltt_kernel_session *ksession;
2605 struct ltt_ust_session *usess;
2606
2607 /* Short cut */
2608 ksession = session->kernel_session;
2609 usess = session->ust_session;
2610
2611 if (!session->enabled)
2612 return LTTCOMM_UST_START_FAIL;
2613 session->enabled = 0;
2614
2615 /* Kernel tracer */
2616 if (ksession != NULL) {
2617 DBG("Stop kernel tracing");
2618
2619 /* Flush all buffers before stopping */
2620 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2621 if (ret < 0) {
2622 ERR("Kernel metadata flush failed");
2623 }
2624
2625 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2626 ret = kernel_flush_buffer(kchan);
2627 if (ret < 0) {
2628 ERR("Kernel flush buffer error");
2629 }
2630 }
2631
2632 ret = kernel_stop_session(ksession);
2633 if (ret < 0) {
2634 ret = LTTCOMM_KERN_STOP_FAIL;
2635 goto error;
2636 }
2637
2638 kernel_wait_quiescent(kernel_tracer_fd);
2639 }
2640
2641 /* Flag session that trace should start automatically */
2642 if (usess) {
2643 usess->start_trace = 0;
2644
2645 ret = ust_app_stop_trace_all(usess);
2646 if (ret < 0) {
2647 ret = LTTCOMM_UST_START_FAIL;
2648 goto error;
2649 }
2650 }
2651
2652 ret = LTTCOMM_OK;
2653
2654 error:
2655 return ret;
2656 }
2657
2658 /*
2659 * Command LTTNG_CREATE_SESSION processed by the client thread.
2660 */
2661 static int cmd_create_session(char *name, char *path)
2662 {
2663 int ret;
2664
2665 ret = session_create(name, path);
2666 if (ret != LTTCOMM_OK) {
2667 goto error;
2668 }
2669
2670 ret = LTTCOMM_OK;
2671
2672 error:
2673 return ret;
2674 }
2675
2676 /*
2677 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2678 */
2679 static int cmd_destroy_session(struct ltt_session *session, char *name)
2680 {
2681 int ret;
2682
2683 /* Clean kernel session teardown */
2684 teardown_kernel_session(session);
2685 /* UST session teardown */
2686 teardown_ust_session(session);
2687
2688 /*
2689 * Must notify the kernel thread here to update it's poll setin order
2690 * to remove the channel(s)' fd just destroyed.
2691 */
2692 ret = notify_thread_pipe(kernel_poll_pipe[1]);
2693 if (ret < 0) {
2694 perror("write kernel poll pipe");
2695 }
2696
2697 ret = session_destroy(session);
2698
2699 return ret;
2700 }
2701
2702 /*
2703 * Command LTTNG_CALIBRATE processed by the client thread.
2704 */
2705 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2706 {
2707 int ret;
2708
2709 switch (domain) {
2710 case LTTNG_DOMAIN_KERNEL:
2711 {
2712 struct lttng_kernel_calibrate kcalibrate;
2713
2714 kcalibrate.type = calibrate->type;
2715 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2716 if (ret < 0) {
2717 ret = LTTCOMM_KERN_ENABLE_FAIL;
2718 goto error;
2719 }
2720 break;
2721 }
2722 default:
2723 /* TODO: Userspace tracing */
2724 ret = LTTCOMM_NOT_IMPLEMENTED;
2725 goto error;
2726 }
2727
2728 ret = LTTCOMM_OK;
2729
2730 error:
2731 return ret;
2732 }
2733
2734 /*
2735 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2736 */
2737 static int cmd_register_consumer(struct ltt_session *session, int domain,
2738 char *sock_path)
2739 {
2740 int ret, sock;
2741
2742 switch (domain) {
2743 case LTTNG_DOMAIN_KERNEL:
2744 /* Can't register a consumer if there is already one */
2745 if (session->kernel_session->consumer_fd != 0) {
2746 ret = LTTCOMM_KERN_CONSUMER_FAIL;
2747 goto error;
2748 }
2749
2750 sock = lttcomm_connect_unix_sock(sock_path);
2751 if (sock < 0) {
2752 ret = LTTCOMM_CONNECT_FAIL;
2753 goto error;
2754 }
2755
2756 session->kernel_session->consumer_fd = sock;
2757 break;
2758 default:
2759 /* TODO: Userspace tracing */
2760 ret = LTTCOMM_NOT_IMPLEMENTED;
2761 goto error;
2762 }
2763
2764 ret = LTTCOMM_OK;
2765
2766 error:
2767 return ret;
2768 }
2769
2770 /*
2771 * Command LTTNG_LIST_DOMAINS processed by the client thread.
2772 */
2773 static ssize_t cmd_list_domains(struct ltt_session *session,
2774 struct lttng_domain **domains)
2775 {
2776 int ret, index = 0;
2777 ssize_t nb_dom = 0;
2778
2779 if (session->kernel_session != NULL) {
2780 DBG3("Listing domains found kernel domain");
2781 nb_dom++;
2782 }
2783
2784 if (session->ust_session != NULL) {
2785 DBG3("Listing domains found UST global domain");
2786 nb_dom++;
2787 }
2788
2789 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
2790 if (*domains == NULL) {
2791 ret = -LTTCOMM_FATAL;
2792 goto error;
2793 }
2794
2795 if (session->kernel_session != NULL) {
2796 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
2797 index++;
2798 }
2799
2800 if (session->ust_session != NULL) {
2801 (*domains)[index].type = LTTNG_DOMAIN_UST;
2802 index++;
2803 }
2804
2805 return nb_dom;
2806
2807 error:
2808 return ret;
2809 }
2810
2811 /*
2812 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2813 */
2814 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2815 struct lttng_channel **channels)
2816 {
2817 int ret;
2818 ssize_t nb_chan = 0;
2819
2820 switch (domain) {
2821 case LTTNG_DOMAIN_KERNEL:
2822 if (session->kernel_session != NULL) {
2823 nb_chan = session->kernel_session->channel_count;
2824 }
2825 DBG3("Number of kernel channels %zd", nb_chan);
2826 break;
2827 case LTTNG_DOMAIN_UST:
2828 if (session->ust_session != NULL) {
2829 nb_chan = hashtable_get_count(
2830 session->ust_session->domain_global.channels);
2831 }
2832 DBG3("Number of UST global channels %zd", nb_chan);
2833 break;
2834 default:
2835 *channels = NULL;
2836 ret = -LTTCOMM_NOT_IMPLEMENTED;
2837 goto error;
2838 }
2839
2840 if (nb_chan > 0) {
2841 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2842 if (*channels == NULL) {
2843 ret = -LTTCOMM_FATAL;
2844 goto error;
2845 }
2846
2847 list_lttng_channels(domain, session, *channels);
2848 } else {
2849 *channels = NULL;
2850 }
2851
2852 return nb_chan;
2853
2854 error:
2855 return ret;
2856 }
2857
2858 /*
2859 * Command LTTNG_LIST_EVENTS processed by the client thread.
2860 */
2861 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
2862 char *channel_name, struct lttng_event **events)
2863 {
2864 int ret = 0;
2865 ssize_t nb_event = 0;
2866
2867 switch (domain) {
2868 case LTTNG_DOMAIN_KERNEL:
2869 if (session->kernel_session != NULL) {
2870 nb_event = list_lttng_kernel_events(channel_name,
2871 session->kernel_session, events);
2872 }
2873 break;
2874 case LTTNG_DOMAIN_UST:
2875 {
2876 if (session->ust_session != NULL) {
2877 nb_event = list_lttng_ust_global_events(channel_name,
2878 &session->ust_session->domain_global, events);
2879 }
2880 break;
2881 }
2882 default:
2883 ret = -LTTCOMM_NOT_IMPLEMENTED;
2884 goto error;
2885 }
2886
2887 ret = nb_event;
2888
2889 error:
2890 return ret;
2891 }
2892
2893 /*
2894 * Process the command requested by the lttng client within the command
2895 * context structure. This function make sure that the return structure (llm)
2896 * is set and ready for transmission before returning.
2897 *
2898 * Return any error encountered or 0 for success.
2899 */
2900 static int process_client_msg(struct command_ctx *cmd_ctx)
2901 {
2902 int ret = LTTCOMM_OK;
2903 int need_tracing_session = 1;
2904
2905 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
2906
2907 /*
2908 * Check for command that don't needs to allocate a returned payload. We do
2909 * this here so we don't have to make the call for no payload at each
2910 * command.
2911 */
2912 switch(cmd_ctx->lsm->cmd_type) {
2913 case LTTNG_LIST_SESSIONS:
2914 case LTTNG_LIST_TRACEPOINTS:
2915 case LTTNG_LIST_DOMAINS:
2916 case LTTNG_LIST_CHANNELS:
2917 case LTTNG_LIST_EVENTS:
2918 break;
2919 default:
2920 /* Setup lttng message with no payload */
2921 ret = setup_lttng_msg(cmd_ctx, 0);
2922 if (ret < 0) {
2923 /* This label does not try to unlock the session */
2924 goto init_setup_error;
2925 }
2926 }
2927
2928 /* Commands that DO NOT need a session. */
2929 switch (cmd_ctx->lsm->cmd_type) {
2930 case LTTNG_CALIBRATE:
2931 case LTTNG_CREATE_SESSION:
2932 case LTTNG_LIST_SESSIONS:
2933 case LTTNG_LIST_TRACEPOINTS:
2934 need_tracing_session = 0;
2935 break;
2936 default:
2937 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
2938 session_lock_list();
2939 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
2940 session_unlock_list();
2941 if (cmd_ctx->session == NULL) {
2942 if (cmd_ctx->lsm->session.name != NULL) {
2943 ret = LTTCOMM_SESS_NOT_FOUND;
2944 } else {
2945 /* If no session name specified */
2946 ret = LTTCOMM_SELECT_SESS;
2947 }
2948 goto error;
2949 } else {
2950 /* Acquire lock for the session */
2951 session_lock(cmd_ctx->session);
2952 }
2953 break;
2954 }
2955
2956 /*
2957 * Check domain type for specific "pre-action".
2958 */
2959 switch (cmd_ctx->lsm->domain.type) {
2960 case LTTNG_DOMAIN_KERNEL:
2961 /* Kernel tracer check */
2962 if (kernel_tracer_fd == 0) {
2963 /* Basically, load kernel tracer modules */
2964 init_kernel_tracer();
2965 if (kernel_tracer_fd == 0) {
2966 ret = LTTCOMM_KERN_NA;
2967 goto error;
2968 }
2969 }
2970
2971 /* Need a session for kernel command */
2972 if (need_tracing_session) {
2973 if (cmd_ctx->session->kernel_session == NULL) {
2974 ret = create_kernel_session(cmd_ctx->session);
2975 if (ret < 0) {
2976 ret = LTTCOMM_KERN_SESS_FAIL;
2977 goto error;
2978 }
2979 }
2980
2981 /* Start the kernel consumer daemon */
2982 pthread_mutex_lock(&kconsumer_data.pid_mutex);
2983 if (kconsumer_data.pid == 0 &&
2984 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
2985 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2986 ret = start_consumerd(&kconsumer_data);
2987 if (ret < 0) {
2988 ret = LTTCOMM_KERN_CONSUMER_FAIL;
2989 goto error;
2990 }
2991 }
2992 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
2993 }
2994 break;
2995 case LTTNG_DOMAIN_UST:
2996 {
2997 if (need_tracing_session) {
2998 if (cmd_ctx->session->ust_session == NULL) {
2999 ret = create_ust_session(cmd_ctx->session,
3000 &cmd_ctx->lsm->domain);
3001 if (ret != LTTCOMM_OK) {
3002 goto error;
3003 }
3004 }
3005 /* Start the kernel consumer daemon */
3006 pthread_mutex_lock(&ustconsumer_data.pid_mutex);
3007 if (ustconsumer_data.pid == 0 &&
3008 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3009 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3010 ret = start_consumerd(&ustconsumer_data);
3011 if (ret < 0) {
3012 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3013 goto error;
3014 }
3015
3016 ust_consumer_fd = ustconsumer_data.cmd_sock;
3017 }
3018 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3019 }
3020 break;
3021 }
3022 default:
3023 break;
3024 }
3025
3026 /* Process by command type */
3027 switch (cmd_ctx->lsm->cmd_type) {
3028 case LTTNG_ADD_CONTEXT:
3029 {
3030 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3031 cmd_ctx->lsm->u.context.channel_name,
3032 cmd_ctx->lsm->u.context.event_name,
3033 &cmd_ctx->lsm->u.context.ctx);
3034 break;
3035 }
3036 case LTTNG_DISABLE_CHANNEL:
3037 {
3038 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3039 cmd_ctx->lsm->u.disable.channel_name);
3040 break;
3041 }
3042 case LTTNG_DISABLE_EVENT:
3043 {
3044 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3045 cmd_ctx->lsm->u.disable.channel_name,
3046 cmd_ctx->lsm->u.disable.name);
3047 ret = LTTCOMM_OK;
3048 break;
3049 }
3050 case LTTNG_DISABLE_ALL_EVENT:
3051 {
3052 DBG("Disabling all events");
3053
3054 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3055 cmd_ctx->lsm->u.disable.channel_name);
3056 break;
3057 }
3058 case LTTNG_ENABLE_CHANNEL:
3059 {
3060 ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
3061 &cmd_ctx->lsm->u.channel.chan);
3062 break;
3063 }
3064 case LTTNG_ENABLE_EVENT:
3065 {
3066 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3067 cmd_ctx->lsm->u.enable.channel_name,
3068 &cmd_ctx->lsm->u.enable.event);
3069 break;
3070 }
3071 case LTTNG_ENABLE_ALL_EVENT:
3072 {
3073 DBG("Enabling all events");
3074
3075 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3076 cmd_ctx->lsm->u.enable.channel_name,
3077 cmd_ctx->lsm->u.enable.event.type);
3078 break;
3079 }
3080 case LTTNG_LIST_TRACEPOINTS:
3081 {
3082 struct lttng_event *events;
3083 ssize_t nb_events;
3084
3085 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
3086 if (nb_events < 0) {
3087 ret = -nb_events;
3088 goto error;
3089 }
3090
3091 /*
3092 * Setup lttng message with payload size set to the event list size in
3093 * bytes and then copy list into the llm payload.
3094 */
3095 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
3096 if (ret < 0) {
3097 free(events);
3098 goto setup_error;
3099 }
3100
3101 /* Copy event list into message payload */
3102 memcpy(cmd_ctx->llm->payload, events,
3103 sizeof(struct lttng_event) * nb_events);
3104
3105 free(events);
3106
3107 ret = LTTCOMM_OK;
3108 break;
3109 }
3110 case LTTNG_START_TRACE:
3111 {
3112 ret = cmd_start_trace(cmd_ctx->session);
3113 break;
3114 }
3115 case LTTNG_STOP_TRACE:
3116 {
3117 ret = cmd_stop_trace(cmd_ctx->session);
3118 break;
3119 }
3120 case LTTNG_CREATE_SESSION:
3121 {
3122 ret = cmd_create_session(cmd_ctx->lsm->session.name,
3123 cmd_ctx->lsm->session.path);
3124 break;
3125 }
3126 case LTTNG_DESTROY_SESSION:
3127 {
3128 ret = cmd_destroy_session(cmd_ctx->session,
3129 cmd_ctx->lsm->session.name);
3130 break;
3131 }
3132 case LTTNG_LIST_DOMAINS:
3133 {
3134 ssize_t nb_dom;
3135 struct lttng_domain *domains;
3136
3137 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
3138 if (nb_dom < 0) {
3139 ret = -nb_dom;
3140 goto error;
3141 }
3142
3143 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
3144 if (ret < 0) {
3145 goto setup_error;
3146 }
3147
3148 /* Copy event list into message payload */
3149 memcpy(cmd_ctx->llm->payload, domains,
3150 nb_dom * sizeof(struct lttng_domain));
3151
3152 free(domains);
3153
3154 ret = LTTCOMM_OK;
3155 break;
3156 }
3157 case LTTNG_LIST_CHANNELS:
3158 {
3159 size_t nb_chan;
3160 struct lttng_channel *channels;
3161
3162 nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
3163 cmd_ctx->session, &channels);
3164 if (nb_chan < 0) {
3165 ret = -nb_chan;
3166 goto error;
3167 }
3168
3169 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3170 if (ret < 0) {
3171 goto setup_error;
3172 }
3173
3174 /* Copy event list into message payload */
3175 memcpy(cmd_ctx->llm->payload, channels,
3176 nb_chan * sizeof(struct lttng_channel));
3177
3178 free(channels);
3179
3180 ret = LTTCOMM_OK;
3181 break;
3182 }
3183 case LTTNG_LIST_EVENTS:
3184 {
3185 ssize_t nb_event;
3186 struct lttng_event *events = NULL;
3187
3188 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
3189 cmd_ctx->lsm->u.list.channel_name, &events);
3190 if (nb_event < 0) {
3191 ret = -nb_event;
3192 goto error;
3193 }
3194
3195 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3196 if (ret < 0) {
3197 goto setup_error;
3198 }
3199
3200 /* Copy event list into message payload */
3201 memcpy(cmd_ctx->llm->payload, events,
3202 nb_event * sizeof(struct lttng_event));
3203
3204 free(events);
3205
3206 ret = LTTCOMM_OK;
3207 break;
3208 }
3209 case LTTNG_LIST_SESSIONS:
3210 {
3211 session_lock_list();
3212
3213 if (session_list_ptr->count == 0) {
3214 ret = LTTCOMM_NO_SESSION;
3215 session_unlock_list();
3216 goto error;
3217 }
3218
3219 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
3220 session_list_ptr->count);
3221 if (ret < 0) {
3222 session_unlock_list();
3223 goto setup_error;
3224 }
3225
3226 /* Filled the session array */
3227 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
3228
3229 session_unlock_list();
3230
3231 ret = LTTCOMM_OK;
3232 break;
3233 }
3234 case LTTNG_CALIBRATE:
3235 {
3236 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3237 &cmd_ctx->lsm->u.calibrate);
3238 break;
3239 }
3240 case LTTNG_REGISTER_CONSUMER:
3241 {
3242 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3243 cmd_ctx->lsm->u.reg.path);
3244 break;
3245 }
3246 default:
3247 ret = LTTCOMM_UND;
3248 break;
3249 }
3250
3251 error:
3252 if (cmd_ctx->llm == NULL) {
3253 DBG("Missing llm structure. Allocating one.");
3254 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3255 goto setup_error;
3256 }
3257 }
3258 /* Set return code */
3259 cmd_ctx->llm->ret_code = ret;
3260 setup_error:
3261 if (cmd_ctx->session) {
3262 session_unlock(cmd_ctx->session);
3263 }
3264 init_setup_error:
3265 return ret;
3266 }
3267
3268 /*
3269 * This thread manage all clients request using the unix client socket for
3270 * communication.
3271 */
3272 static void *thread_manage_clients(void *data)
3273 {
3274 int sock = 0, ret, i, pollfd;
3275 uint32_t revents, nb_fd;
3276 struct command_ctx *cmd_ctx = NULL;
3277 struct lttng_poll_event events;
3278
3279 DBG("[thread] Manage client started");
3280
3281 rcu_register_thread();
3282
3283 ret = lttcomm_listen_unix_sock(client_sock);
3284 if (ret < 0) {
3285 goto error;
3286 }
3287
3288 /*
3289 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
3290 * more will be added to this poll set.
3291 */
3292 ret = create_thread_poll_set(&events, 2);
3293 if (ret < 0) {
3294 goto error;
3295 }
3296
3297 /* Add the application registration socket */
3298 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
3299 if (ret < 0) {
3300 goto error;
3301 }
3302
3303 /*
3304 * Notify parent pid that we are ready to accept command for client side.
3305 */
3306 if (opt_sig_parent) {
3307 kill(ppid, SIGCHLD);
3308 }
3309
3310 while (1) {
3311 DBG("Accepting client command ...");
3312
3313 nb_fd = LTTNG_POLL_GETNB(&events);
3314
3315 /* Inifinite blocking call, waiting for transmission */
3316 ret = lttng_poll_wait(&events, -1);
3317 if (ret < 0) {
3318 goto error;
3319 }
3320
3321 for (i = 0; i < nb_fd; i++) {
3322 /* Fetch once the poll data */
3323 revents = LTTNG_POLL_GETEV(&events, i);
3324 pollfd = LTTNG_POLL_GETFD(&events, i);
3325
3326 /* Thread quit pipe has been closed. Killing thread. */
3327 ret = check_thread_quit_pipe(pollfd, revents);
3328 if (ret) {
3329 goto error;
3330 }
3331
3332 /* Event on the registration socket */
3333 if (pollfd == client_sock) {
3334 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3335 ERR("Client socket poll error");
3336 goto error;
3337 }
3338 }
3339 }
3340
3341 DBG("Wait for client response");
3342
3343 sock = lttcomm_accept_unix_sock(client_sock);
3344 if (sock < 0) {
3345 goto error;
3346 }
3347
3348 /* Allocate context command to process the client request */
3349 cmd_ctx = zmalloc(sizeof(struct command_ctx));
3350 if (cmd_ctx == NULL) {
3351 perror("zmalloc cmd_ctx");
3352 goto error;
3353 }
3354
3355 /* Allocate data buffer for reception */
3356 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
3357 if (cmd_ctx->lsm == NULL) {
3358 perror("zmalloc cmd_ctx->lsm");
3359 goto error;
3360 }
3361
3362 cmd_ctx->llm = NULL;
3363 cmd_ctx->session = NULL;
3364
3365 /*
3366 * Data is received from the lttng client. The struct
3367 * lttcomm_session_msg (lsm) contains the command and data request of
3368 * the client.
3369 */
3370 DBG("Receiving data from client ...");
3371 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm,
3372 sizeof(struct lttcomm_session_msg));
3373 if (ret <= 0) {
3374 DBG("Nothing recv() from client... continuing");
3375 close(sock);
3376 free(cmd_ctx);
3377 continue;
3378 }
3379
3380 // TODO: Validate cmd_ctx including sanity check for
3381 // security purpose.
3382
3383 rcu_thread_online();
3384 /*
3385 * This function dispatch the work to the kernel or userspace tracer
3386 * libs and fill the lttcomm_lttng_msg data structure of all the needed
3387 * informations for the client. The command context struct contains
3388 * everything this function may needs.
3389 */
3390 ret = process_client_msg(cmd_ctx);
3391 rcu_thread_offline();
3392 if (ret < 0) {
3393 /*
3394 * TODO: Inform client somehow of the fatal error. At
3395 * this point, ret < 0 means that a zmalloc failed
3396 * (ENOMEM). Error detected but still accept command.
3397 */
3398 clean_command_ctx(&cmd_ctx);
3399 continue;
3400 }
3401
3402 DBG("Sending response (size: %d, retcode: %s)",
3403 cmd_ctx->lttng_msg_size,
3404 lttng_strerror(-cmd_ctx->llm->ret_code));
3405 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
3406 if (ret < 0) {
3407 ERR("Failed to send data back to client");
3408 }
3409
3410 clean_command_ctx(&cmd_ctx);
3411
3412 /* End of transmission */
3413 close(sock);
3414 }
3415
3416 error:
3417 DBG("Client thread dying");
3418 unlink(client_unix_sock_path);
3419 close(client_sock);
3420 close(sock);
3421
3422 lttng_poll_clean(&events);
3423 clean_command_ctx(&cmd_ctx);
3424
3425 rcu_unregister_thread();
3426 return NULL;
3427 }
3428
3429
3430 /*
3431 * usage function on stderr
3432 */
3433 static void usage(void)
3434 {
3435 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
3436 fprintf(stderr, " -h, --help Display this usage.\n");
3437 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
3438 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
3439 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
3440 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
3441 fprintf(stderr, " --ustconsumerd-err-sock PATH Specify path for the UST consumer error socket\n");
3442 fprintf(stderr, " --ustconsumerd-cmd-sock PATH Specify path for the UST consumer command socket\n");
3443 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
3444 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
3445 fprintf(stderr, " -V, --version Show version number.\n");
3446 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
3447 fprintf(stderr, " -q, --quiet No output at all.\n");
3448 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
3449 fprintf(stderr, " --verbose-consumer Verbose mode for consumer. Activate DBG() macro.\n");
3450 }
3451
3452 /*
3453 * daemon argument parsing
3454 */
3455 static int parse_args(int argc, char **argv)
3456 {
3457 int c;
3458
3459 static struct option long_options[] = {
3460 { "client-sock", 1, 0, 'c' },
3461 { "apps-sock", 1, 0, 'a' },
3462 { "kconsumerd-cmd-sock", 1, 0, 'C' },
3463 { "kconsumerd-err-sock", 1, 0, 'E' },
3464 { "ustconsumerd-cmd-sock", 1, 0, 'D' },
3465 { "ustconsumerd-err-sock", 1, 0, 'F' },
3466 { "daemonize", 0, 0, 'd' },
3467 { "sig-parent", 0, 0, 'S' },
3468 { "help", 0, 0, 'h' },
3469 { "group", 1, 0, 'g' },
3470 { "version", 0, 0, 'V' },
3471 { "quiet", 0, 0, 'q' },
3472 { "verbose", 0, 0, 'v' },
3473 { "verbose-consumer", 0, 0, 'Z' },
3474 { NULL, 0, 0, 0 }
3475 };
3476
3477 while (1) {
3478 int option_index = 0;
3479 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:C:E:D:F:Z",
3480 long_options, &option_index);
3481 if (c == -1) {
3482 break;
3483 }
3484
3485 switch (c) {
3486 case 0:
3487 fprintf(stderr, "option %s", long_options[option_index].name);
3488 if (optarg) {
3489 fprintf(stderr, " with arg %s\n", optarg);
3490 }
3491 break;
3492 case 'c':
3493 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
3494 break;
3495 case 'a':
3496 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
3497 break;
3498 case 'd':
3499 opt_daemon = 1;
3500 break;
3501 case 'g':
3502 opt_tracing_group = strdup(optarg);
3503 break;
3504 case 'h':
3505 usage();
3506 exit(EXIT_FAILURE);
3507 case 'V':
3508 fprintf(stdout, "%s\n", VERSION);
3509 exit(EXIT_SUCCESS);
3510 case 'S':
3511 opt_sig_parent = 1;
3512 break;
3513 case 'E':
3514 snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3515 break;
3516 case 'C':
3517 snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3518 break;
3519 case 'F':
3520 snprintf(ustconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3521 break;
3522 case 'D':
3523 snprintf(ustconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3524 break;
3525 case 'q':
3526 opt_quiet = 1;
3527 break;
3528 case 'v':
3529 /* Verbose level can increase using multiple -v */
3530 opt_verbose += 1;
3531 break;
3532 case 'Z':
3533 opt_verbose_consumer += 1;
3534 break;
3535 default:
3536 /* Unknown option or other error.
3537 * Error is printed by getopt, just return */
3538 return -1;
3539 }
3540 }
3541
3542 return 0;
3543 }
3544
3545 /*
3546 * Creates the two needed socket by the daemon.
3547 * apps_sock - The communication socket for all UST apps.
3548 * client_sock - The communication of the cli tool (lttng).
3549 */
3550 static int init_daemon_socket(void)
3551 {
3552 int ret = 0;
3553 mode_t old_umask;
3554
3555 old_umask = umask(0);
3556
3557 /* Create client tool unix socket */
3558 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
3559 if (client_sock < 0) {
3560 ERR("Create unix sock failed: %s", client_unix_sock_path);
3561 ret = -1;
3562 goto end;
3563 }
3564
3565 /* File permission MUST be 660 */
3566 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3567 if (ret < 0) {
3568 ERR("Set file permissions failed: %s", client_unix_sock_path);
3569 perror("chmod");
3570 goto end;
3571 }
3572
3573 /* Create the application unix socket */
3574 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
3575 if (apps_sock < 0) {
3576 ERR("Create unix sock failed: %s", apps_unix_sock_path);
3577 ret = -1;
3578 goto end;
3579 }
3580
3581 /* File permission MUST be 666 */
3582 ret = chmod(apps_unix_sock_path,
3583 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
3584 if (ret < 0) {
3585 ERR("Set file permissions failed: %s", apps_unix_sock_path);
3586 perror("chmod");
3587 goto end;
3588 }
3589
3590 end:
3591 umask(old_umask);
3592 return ret;
3593 }
3594
3595 /*
3596 * Check if the global socket is available, and if a daemon is answering at the
3597 * other side. If yes, error is returned.
3598 */
3599 static int check_existing_daemon(void)
3600 {
3601 if (access(client_unix_sock_path, F_OK) < 0 &&
3602 access(apps_unix_sock_path, F_OK) < 0) {
3603 return 0;
3604 }
3605
3606 /* Is there anybody out there ? */
3607 if (lttng_session_daemon_alive()) {
3608 return -EEXIST;
3609 } else {
3610 return 0;
3611 }
3612 }
3613
3614 /*
3615 * Set the tracing group gid onto the client socket.
3616 *
3617 * Race window between mkdir and chown is OK because we are going from more
3618 * permissive (root.root) to les permissive (root.tracing).
3619 */
3620 static int set_permissions(void)
3621 {
3622 int ret;
3623 gid_t gid;
3624
3625 gid = allowed_group();
3626 if (gid < 0) {
3627 if (is_root) {
3628 WARN("No tracing group detected");
3629 ret = 0;
3630 } else {
3631 ERR("Missing tracing group. Aborting execution.");
3632 ret = -1;
3633 }
3634 goto end;
3635 }
3636
3637 /* Set lttng run dir */
3638 ret = chown(LTTNG_RUNDIR, 0, gid);
3639 if (ret < 0) {
3640 ERR("Unable to set group on " LTTNG_RUNDIR);
3641 perror("chown");
3642 }
3643
3644 /* lttng client socket path */
3645 ret = chown(client_unix_sock_path, 0, gid);
3646 if (ret < 0) {
3647 ERR("Unable to set group on %s", client_unix_sock_path);
3648 perror("chown");
3649 }
3650
3651 /* kconsumer error socket path */
3652 ret = chown(kconsumer_data.err_unix_sock_path, 0, gid);
3653 if (ret < 0) {
3654 ERR("Unable to set group on %s", kconsumer_data.err_unix_sock_path);
3655 perror("chown");
3656 }
3657
3658 /* ustconsumer error socket path */
3659 ret = chown(ustconsumer_data.err_unix_sock_path, 0, gid);
3660 if (ret < 0) {
3661 ERR("Unable to set group on %s", ustconsumer_data.err_unix_sock_path);
3662 perror("chown");
3663 }
3664
3665 DBG("All permissions are set");
3666
3667 end:
3668 return ret;
3669 }
3670
3671 /*
3672 * Create the pipe used to wake up the kernel thread.
3673 */
3674 static int create_kernel_poll_pipe(void)
3675 {
3676 return pipe2(kernel_poll_pipe, O_CLOEXEC);
3677 }
3678
3679 /*
3680 * Create the application command pipe to wake thread_manage_apps.
3681 */
3682 static int create_apps_cmd_pipe(void)
3683 {
3684 return pipe2(apps_cmd_pipe, O_CLOEXEC);
3685 }
3686
3687 /*
3688 * Create the lttng run directory needed for all global sockets and pipe.
3689 */
3690 static int create_lttng_rundir(void)
3691 {
3692 int ret;
3693
3694 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
3695 if (ret < 0) {
3696 if (errno != EEXIST) {
3697 ERR("Unable to create " LTTNG_RUNDIR);
3698 goto error;
3699 } else {
3700 ret = 0;
3701 }
3702 }
3703
3704 error:
3705 return ret;
3706 }
3707
3708 /*
3709 * Setup sockets and directory needed by the kconsumerd communication with the
3710 * session daemon.
3711 */
3712 static int set_consumer_sockets(struct consumer_data *consumer_data)
3713 {
3714 int ret;
3715 const char *path = consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3716 KCONSUMERD_PATH : USTCONSUMERD_PATH;
3717
3718 if (strlen(consumer_data->err_unix_sock_path) == 0) {
3719 snprintf(consumer_data->err_unix_sock_path, PATH_MAX,
3720 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3721 KCONSUMERD_ERR_SOCK_PATH :
3722 USTCONSUMERD_ERR_SOCK_PATH);
3723 }
3724
3725 if (strlen(consumer_data->cmd_unix_sock_path) == 0) {
3726 snprintf(consumer_data->cmd_unix_sock_path, PATH_MAX,
3727 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3728 KCONSUMERD_CMD_SOCK_PATH :
3729 USTCONSUMERD_CMD_SOCK_PATH);
3730 }
3731
3732 ret = mkdir(path, S_IRWXU | S_IRWXG);
3733 if (ret < 0) {
3734 if (errno != EEXIST) {
3735 ERR("Failed to create %s", path);
3736 goto error;
3737 }
3738 ret = 0;
3739 }
3740
3741 /* Create the kconsumerd error unix socket */
3742 consumer_data->err_sock =
3743 lttcomm_create_unix_sock(consumer_data->err_unix_sock_path);
3744 if (consumer_data->err_sock < 0) {
3745 ERR("Create unix sock failed: %s", consumer_data->err_unix_sock_path);
3746 ret = -1;
3747 goto error;
3748 }
3749
3750 /* File permission MUST be 660 */
3751 ret = chmod(consumer_data->err_unix_sock_path,
3752 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3753 if (ret < 0) {
3754 ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
3755 perror("chmod");
3756 goto error;
3757 }
3758
3759 error:
3760 return ret;
3761 }
3762
3763 /*
3764 * Signal handler for the daemon
3765 *
3766 * Simply stop all worker threads, leaving main() return gracefully after
3767 * joining all threads and calling cleanup().
3768 */
3769 static void sighandler(int sig)
3770 {
3771 switch (sig) {
3772 case SIGPIPE:
3773 DBG("SIGPIPE catched");
3774 return;
3775 case SIGINT:
3776 DBG("SIGINT catched");
3777 stop_threads();
3778 break;
3779 case SIGTERM:
3780 DBG("SIGTERM catched");
3781 stop_threads();
3782 break;
3783 default:
3784 break;
3785 }
3786 }
3787
3788 /*
3789 * Setup signal handler for :
3790 * SIGINT, SIGTERM, SIGPIPE
3791 */
3792 static int set_signal_handler(void)
3793 {
3794 int ret = 0;
3795 struct sigaction sa;
3796 sigset_t sigset;
3797
3798 if ((ret = sigemptyset(&sigset)) < 0) {
3799 perror("sigemptyset");
3800 return ret;
3801 }
3802
3803 sa.sa_handler = sighandler;
3804 sa.sa_mask = sigset;
3805 sa.sa_flags = 0;
3806 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
3807 perror("sigaction");
3808 return ret;
3809 }
3810
3811 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
3812 perror("sigaction");
3813 return ret;
3814 }
3815
3816 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
3817 perror("sigaction");
3818 return ret;
3819 }
3820
3821 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
3822
3823 return ret;
3824 }
3825
3826 /*
3827 * Set open files limit to unlimited. This daemon can open a large number of
3828 * file descriptors in order to consumer multiple kernel traces.
3829 */
3830 static void set_ulimit(void)
3831 {
3832 int ret;
3833 struct rlimit lim;
3834
3835 /* The kernel does not allowed an infinite limit for open files */
3836 lim.rlim_cur = 65535;
3837 lim.rlim_max = 65535;
3838
3839 ret = setrlimit(RLIMIT_NOFILE, &lim);
3840 if (ret < 0) {
3841 perror("failed to set open files limit");
3842 }
3843 }
3844
3845 /*
3846 * main
3847 */
3848 int main(int argc, char **argv)
3849 {
3850 int ret = 0;
3851 void *status;
3852 const char *home_path;
3853
3854 rcu_register_thread();
3855
3856 /* Create thread quit pipe */
3857 if ((ret = init_thread_quit_pipe()) < 0) {
3858 goto error;
3859 }
3860
3861 /* Parse arguments */
3862 progname = argv[0];
3863 if ((ret = parse_args(argc, argv) < 0)) {
3864 goto error;
3865 }
3866
3867 /* Daemonize */
3868 if (opt_daemon) {
3869 ret = daemon(0, 0);
3870 if (ret < 0) {
3871 perror("daemon");
3872 goto error;
3873 }
3874 }
3875
3876 /* Check if daemon is UID = 0 */
3877 is_root = !getuid();
3878
3879 if (is_root) {
3880 ret = create_lttng_rundir();
3881 if (ret < 0) {
3882 goto error;
3883 }
3884
3885 if (strlen(apps_unix_sock_path) == 0) {
3886 snprintf(apps_unix_sock_path, PATH_MAX,
3887 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
3888 }
3889
3890 if (strlen(client_unix_sock_path) == 0) {
3891 snprintf(client_unix_sock_path, PATH_MAX,
3892 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
3893 }
3894
3895 /* Set global SHM for ust */
3896 if (strlen(wait_shm_path) == 0) {
3897 snprintf(wait_shm_path, PATH_MAX,
3898 DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
3899 }
3900 } else {
3901 home_path = get_home_dir();
3902 if (home_path == NULL) {
3903 /* TODO: Add --socket PATH option */
3904 ERR("Can't get HOME directory for sockets creation.");
3905 ret = -EPERM;
3906 goto error;
3907 }
3908
3909 if (strlen(apps_unix_sock_path) == 0) {
3910 snprintf(apps_unix_sock_path, PATH_MAX,
3911 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
3912 }
3913
3914 /* Set the cli tool unix socket path */
3915 if (strlen(client_unix_sock_path) == 0) {
3916 snprintf(client_unix_sock_path, PATH_MAX,
3917 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
3918 }
3919
3920 /* Set global SHM for ust */
3921 if (strlen(wait_shm_path) == 0) {
3922 snprintf(wait_shm_path, PATH_MAX,
3923 DEFAULT_HOME_APPS_WAIT_SHM_PATH, geteuid());
3924 }
3925 }
3926
3927 DBG("Client socket path %s", client_unix_sock_path);
3928 DBG("Application socket path %s", apps_unix_sock_path);
3929
3930 /*
3931 * See if daemon already exist.
3932 */
3933 if ((ret = check_existing_daemon()) < 0) {
3934 ERR("Already running daemon.\n");
3935 /*
3936 * We do not goto exit because we must not cleanup()
3937 * because a daemon is already running.
3938 */
3939 goto error;
3940 }
3941
3942 /* After this point, we can safely call cleanup() with "goto exit" */
3943
3944 /*
3945 * These actions must be executed as root. We do that *after* setting up
3946 * the sockets path because we MUST make the check for another daemon using
3947 * those paths *before* trying to set the kernel consumer sockets and init
3948 * kernel tracer.
3949 */
3950 if (is_root) {
3951 ret = set_consumer_sockets(&kconsumer_data);
3952 if (ret < 0) {
3953 goto exit;
3954 }
3955
3956 ret = set_consumer_sockets(&ustconsumer_data);
3957 if (ret < 0) {
3958 goto exit;
3959 }
3960 /* Setup kernel tracer */
3961 init_kernel_tracer();
3962
3963 /* Set ulimit for open files */
3964 set_ulimit();
3965 }
3966
3967 if ((ret = set_signal_handler()) < 0) {
3968 goto exit;
3969 }
3970
3971 /* Setup the needed unix socket */
3972 if ((ret = init_daemon_socket()) < 0) {
3973 goto exit;
3974 }
3975
3976 /* Set credentials to socket */
3977 if (is_root && ((ret = set_permissions()) < 0)) {
3978 goto exit;
3979 }
3980
3981 /* Get parent pid if -S, --sig-parent is specified. */
3982 if (opt_sig_parent) {
3983 ppid = getppid();
3984 }
3985
3986 /* Setup the kernel pipe for waking up the kernel thread */
3987 if ((ret = create_kernel_poll_pipe()) < 0) {
3988 goto exit;
3989 }
3990
3991 /* Setup the thread apps communication pipe. */
3992 if ((ret = create_apps_cmd_pipe()) < 0) {
3993 goto exit;
3994 }
3995
3996 /* Init UST command queue. */
3997 cds_wfq_init(&ust_cmd_queue.queue);
3998
3999 /* Init UST app hash table */
4000 ust_app_ht_alloc();
4001
4002 /*
4003 * Get session list pointer. This pointer MUST NOT be free(). This list is
4004 * statically declared in session.c
4005 */
4006 session_list_ptr = session_get_list();
4007
4008 /* Set up max poll set size */
4009 lttng_poll_set_max_size();
4010
4011 /* Create thread to manage the client socket */
4012 ret = pthread_create(&client_thread, NULL,
4013 thread_manage_clients, (void *) NULL);
4014 if (ret != 0) {
4015 perror("pthread_create clients");
4016 goto exit_client;
4017 }
4018
4019 /* Create thread to dispatch registration */
4020 ret = pthread_create(&dispatch_thread, NULL,
4021 thread_dispatch_ust_registration, (void *) NULL);
4022 if (ret != 0) {
4023 perror("pthread_create dispatch");
4024 goto exit_dispatch;
4025 }
4026
4027 /* Create thread to manage application registration. */
4028 ret = pthread_create(&reg_apps_thread, NULL,
4029 thread_registration_apps, (void *) NULL);
4030 if (ret != 0) {
4031 perror("pthread_create registration");
4032 goto exit_reg_apps;
4033 }
4034
4035 /* Create thread to manage application socket */
4036 ret = pthread_create(&apps_thread, NULL,
4037 thread_manage_apps, (void *) NULL);
4038 if (ret != 0) {
4039 perror("pthread_create apps");
4040 goto exit_apps;
4041 }
4042
4043 /* Create kernel thread to manage kernel event */
4044 ret = pthread_create(&kernel_thread, NULL,
4045 thread_manage_kernel, (void *) NULL);
4046 if (ret != 0) {
4047 perror("pthread_create kernel");
4048 goto exit_kernel;
4049 }
4050
4051 ret = pthread_join(kernel_thread, &status);
4052 if (ret != 0) {
4053 perror("pthread_join");
4054 goto error; /* join error, exit without cleanup */
4055 }
4056
4057 exit_kernel:
4058 ret = pthread_join(apps_thread, &status);
4059 if (ret != 0) {
4060 perror("pthread_join");
4061 goto error; /* join error, exit without cleanup */
4062 }
4063
4064 exit_apps:
4065 ret = pthread_join(reg_apps_thread, &status);
4066 if (ret != 0) {
4067 perror("pthread_join");
4068 goto error; /* join error, exit without cleanup */
4069 }
4070
4071 exit_reg_apps:
4072 ret = pthread_join(dispatch_thread, &status);
4073 if (ret != 0) {
4074 perror("pthread_join");
4075 goto error; /* join error, exit without cleanup */
4076 }
4077
4078 exit_dispatch:
4079 ret = pthread_join(client_thread, &status);
4080 if (ret != 0) {
4081 perror("pthread_join");
4082 goto error; /* join error, exit without cleanup */
4083 }
4084
4085 ret = join_consumer_thread(&kconsumer_data);
4086 if (ret != 0) {
4087 perror("join_consumer");
4088 goto error; /* join error, exit without cleanup */
4089 }
4090
4091 exit_client:
4092 exit:
4093 /*
4094 * cleanup() is called when no other thread is running.
4095 */
4096 rcu_thread_online();
4097 cleanup();
4098 rcu_thread_offline();
4099 rcu_unregister_thread();
4100 if (!ret)
4101 exit(EXIT_SUCCESS);
4102 error:
4103 exit(EXIT_FAILURE);
4104 }
LTTng 2.0 tools and control repository
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