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