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