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