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d0c1d406863c471cadfb948f43380c9acc62128b
[lttng-tools.git] / lttng-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; only version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <grp.h>
23 #include <limits.h>
24 #include <pthread.h>
25 #include <semaphore.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sys/mman.h>
31 #include <sys/mount.h>
32 #include <sys/resource.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 #include <urcu/futex.h>
38 #include <unistd.h>
39 #include <config.h>
40
41 #include <lttng-consumerd.h>
42 #include <lttng-sessiond-comm.h>
43 #include <lttng/lttng-consumer.h>
44
45 #include <lttngerr.h>
46
47 #include "channel.h"
48 #include "compat/poll.h"
49 #include "context.h"
50 #include "event.h"
51 #include "futex.h"
52 #include "hashtable.h"
53 #include "kernel-ctl.h"
54 #include "lttng-sessiond.h"
55 #include "shm.h"
56 #include "ust-app.h"
57 #include "ust-ctl.h"
58 #include "utils.h"
59
60 struct consumer_data {
61 enum lttng_consumer_type type;
62
63 pthread_t thread; /* Worker thread interacting with the consumer */
64 sem_t sem;
65
66 /* Mutex to control consumerd pid assignation */
67 pthread_mutex_t pid_mutex;
68 pid_t pid;
69
70 int err_sock;
71 int cmd_sock;
72
73 /* consumer error and command Unix socket path */
74 char err_unix_sock_path[PATH_MAX];
75 char cmd_unix_sock_path[PATH_MAX];
76 };
77
78 /* Const values */
79 const char default_home_dir[] = DEFAULT_HOME_DIR;
80 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
81 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
82 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
83
84 /* Variables */
85 int opt_verbose; /* Not static for lttngerr.h */
86 int opt_verbose_consumer; /* Not static for lttngerr.h */
87 int opt_quiet; /* Not static for lttngerr.h */
88
89 const char *progname;
90 const char *opt_tracing_group;
91 static int opt_sig_parent;
92 static int opt_daemon;
93 static int is_root; /* Set to 1 if the daemon is running as root */
94 static pid_t ppid; /* Parent PID for --sig-parent option */
95
96 /* Consumer daemon specific control data */
97 static struct consumer_data kconsumer_data = {
98 .type = LTTNG_CONSUMER_KERNEL,
99 };
100 static struct consumer_data ustconsumer_data = {
101 .type = LTTNG_CONSUMER_UST,
102 };
103
104 static int dispatch_thread_exit;
105
106 /* Global application Unix socket path */
107 static char apps_unix_sock_path[PATH_MAX];
108 /* Global client Unix socket path */
109 static char client_unix_sock_path[PATH_MAX];
110 /* global wait shm path for UST */
111 static char wait_shm_path[PATH_MAX];
112
113 /* Sockets and FDs */
114 static int client_sock;
115 static int apps_sock;
116 static int kernel_tracer_fd;
117 static int kernel_poll_pipe[2];
118
119 /*
120 * Quit pipe for all threads. This permits a single cancellation point
121 * for all threads when receiving an event on the pipe.
122 */
123 static int thread_quit_pipe[2];
124
125 /*
126 * This pipe is used to inform the thread managing application communication
127 * that a command is queued and ready to be processed.
128 */
129 static int apps_cmd_pipe[2];
130
131 /* Pthread, Mutexes and Semaphores */
132 static pthread_t apps_thread;
133 static pthread_t reg_apps_thread;
134 static pthread_t client_thread;
135 static pthread_t kernel_thread;
136 static pthread_t dispatch_thread;
137
138
139 /*
140 * UST registration command queue. This queue is tied with a futex and uses a N
141 * wakers / 1 waiter implemented and detailed in futex.c/.h
142 *
143 * The thread_manage_apps and thread_dispatch_ust_registration interact with
144 * this queue and the wait/wake scheme.
145 */
146 static struct ust_cmd_queue ust_cmd_queue;
147
148 /*
149 * Pointer initialized before thread creation.
150 *
151 * This points to the tracing session list containing the session count and a
152 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
153 * MUST NOT be taken if you call a public function in session.c.
154 *
155 * The lock is nested inside the structure: session_list_ptr->lock. Please use
156 * session_lock_list and session_unlock_list for lock acquisition.
157 */
158 static struct ltt_session_list *session_list_ptr;
159
160 int ust_consumer_fd;
161
162 static const char *compat32_consumer_bindir =
163 __stringify(CONFIG_COMPAT_BIN_DIR);
164 static const char *compat32_consumer_prog = "lttng-consumerd";
165
166 static
167 void setup_compat32_consumer(void)
168 {
169 const char *bindir;
170
171 /*
172 * runtime env. var. overrides the build default.
173 */
174 bindir = getenv("LTTNG_TOOLS_COMPAT_BIN_DIR");
175 if (bindir) {
176 compat32_consumer_bindir = bindir;
177 }
178 }
179
180 /*
181 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
182 */
183 static int create_thread_poll_set(struct lttng_poll_event *events,
184 unsigned int size)
185 {
186 int ret;
187
188 if (events == NULL || size == 0) {
189 ret = -1;
190 goto error;
191 }
192
193 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
194 if (ret < 0) {
195 goto error;
196 }
197
198 /* Add quit pipe */
199 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
200 if (ret < 0) {
201 goto error;
202 }
203
204 return 0;
205
206 error:
207 return ret;
208 }
209
210 /*
211 * Check if the thread quit pipe was triggered.
212 *
213 * Return 1 if it was triggered else 0;
214 */
215 static int check_thread_quit_pipe(int fd, uint32_t events)
216 {
217 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
218 return 1;
219 }
220
221 return 0;
222 }
223
224 /*
225 * Remove modules in reverse load order.
226 */
227 static int modprobe_remove_kernel_modules(void)
228 {
229 int ret = 0, i;
230 char modprobe[256];
231
232 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
233 ret = snprintf(modprobe, sizeof(modprobe),
234 "/sbin/modprobe -r -q %s",
235 kernel_modules_list[i].name);
236 if (ret < 0) {
237 perror("snprintf modprobe -r");
238 goto error;
239 }
240 modprobe[sizeof(modprobe) - 1] = '\0';
241 ret = system(modprobe);
242 if (ret == -1) {
243 ERR("Unable to launch modprobe -r for module %s",
244 kernel_modules_list[i].name);
245 } else if (kernel_modules_list[i].required
246 && WEXITSTATUS(ret) != 0) {
247 ERR("Unable to remove module %s",
248 kernel_modules_list[i].name);
249 } else {
250 DBG("Modprobe removal successful %s",
251 kernel_modules_list[i].name);
252 }
253 }
254
255 error:
256 return ret;
257 }
258
259 /*
260 * Return group ID of the tracing group or -1 if not found.
261 */
262 static gid_t allowed_group(void)
263 {
264 struct group *grp;
265
266 if (opt_tracing_group) {
267 grp = getgrnam(opt_tracing_group);
268 } else {
269 grp = getgrnam(default_tracing_group);
270 }
271 if (!grp) {
272 return -1;
273 } else {
274 return grp->gr_gid;
275 }
276 }
277
278 /*
279 * Init thread quit pipe.
280 *
281 * Return -1 on error or 0 if all pipes are created.
282 */
283 static int init_thread_quit_pipe(void)
284 {
285 int ret;
286
287 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
288 if (ret < 0) {
289 perror("thread quit pipe");
290 goto error;
291 }
292
293 error:
294 return ret;
295 }
296
297 /*
298 * Complete teardown of a kernel session. This free all data structure related
299 * to a kernel session and update counter.
300 */
301 static void teardown_kernel_session(struct ltt_session *session)
302 {
303 if (session->kernel_session != NULL) {
304 DBG("Tearing down kernel session");
305
306 /*
307 * If a custom kernel consumer was registered, close the socket before
308 * tearing down the complete kernel session structure
309 */
310 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
311 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
312 }
313
314 trace_kernel_destroy_session(session->kernel_session);
315 /* Extra precaution */
316 session->kernel_session = NULL;
317 }
318 }
319
320 /*
321 * Complete teardown of all UST sessions. This will free everything on his path
322 * and destroy the core essence of all ust sessions :)
323 */
324 static void teardown_ust_session(struct ltt_session *session)
325 {
326 int ret;
327
328 DBG("Tearing down UST session(s)");
329
330 ret = ust_app_destroy_trace_all(session->ust_session);
331 if (ret) {
332 ERR("Error in ust_app_destroy_trace_all");
333 }
334 trace_ust_destroy_session(session->ust_session);
335 }
336
337 /*
338 * Stop all threads by closing the thread quit pipe.
339 */
340 static void stop_threads(void)
341 {
342 int ret;
343
344 /* Stopping all threads */
345 DBG("Terminating all threads");
346 ret = notify_thread_pipe(thread_quit_pipe[1]);
347 if (ret < 0) {
348 ERR("write error on thread quit pipe");
349 }
350
351 /* Dispatch thread */
352 dispatch_thread_exit = 1;
353 futex_nto1_wake(&ust_cmd_queue.futex);
354 }
355
356 /*
357 * Cleanup the daemon
358 */
359 static void cleanup(void)
360 {
361 int ret;
362 char *cmd;
363 struct ltt_session *sess, *stmp;
364
365 DBG("Cleaning up");
366
367 if (is_root) {
368 DBG("Removing %s directory", LTTNG_RUNDIR);
369 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
370 if (ret < 0) {
371 ERR("asprintf failed. Something is really wrong!");
372 }
373
374 /* Remove lttng run directory */
375 ret = system(cmd);
376 if (ret < 0) {
377 ERR("Unable to clean " LTTNG_RUNDIR);
378 }
379 }
380
381 DBG("Cleaning up all session");
382
383 /* Destroy session list mutex */
384 if (session_list_ptr != NULL) {
385 pthread_mutex_destroy(&session_list_ptr->lock);
386
387 /* Cleanup ALL session */
388 cds_list_for_each_entry_safe(sess, stmp,
389 &session_list_ptr->head, list) {
390 teardown_kernel_session(sess);
391 teardown_ust_session(sess);
392 free(sess);
393 }
394 }
395
396 DBG("Closing all UST sockets");
397 ust_app_clean_list();
398
399 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
400
401 DBG("Closing kernel fd");
402 close(kernel_tracer_fd);
403
404 if (is_root) {
405 DBG("Unloading kernel modules");
406 modprobe_remove_kernel_modules();
407 }
408
409 close(thread_quit_pipe[0]);
410 close(thread_quit_pipe[1]);
411
412 /* <fun> */
413 MSG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
414 "Matthew, BEET driven development works!%c[%dm",
415 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
416 /* </fun> */
417 }
418
419 /*
420 * Send data on a unix socket using the liblttsessiondcomm API.
421 *
422 * Return lttcomm error code.
423 */
424 static int send_unix_sock(int sock, void *buf, size_t len)
425 {
426 /* Check valid length */
427 if (len <= 0) {
428 return -1;
429 }
430
431 return lttcomm_send_unix_sock(sock, buf, len);
432 }
433
434 /*
435 * Free memory of a command context structure.
436 */
437 static void clean_command_ctx(struct command_ctx **cmd_ctx)
438 {
439 DBG("Clean command context structure");
440 if (*cmd_ctx) {
441 if ((*cmd_ctx)->llm) {
442 free((*cmd_ctx)->llm);
443 }
444 if ((*cmd_ctx)->lsm) {
445 free((*cmd_ctx)->lsm);
446 }
447 free(*cmd_ctx);
448 *cmd_ctx = NULL;
449 }
450 }
451
452 /*
453 * Send all stream fds of kernel channel to the consumer.
454 */
455 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
456 int sock, struct ltt_kernel_channel *channel)
457 {
458 int ret;
459 struct ltt_kernel_stream *stream;
460 struct lttcomm_consumer_msg lkm;
461
462 DBG("Sending streams of channel %s to kernel consumer",
463 channel->channel->name);
464
465 /* Send channel */
466 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
467 lkm.u.channel.channel_key = channel->fd;
468 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
469 lkm.u.channel.mmap_len = 0; /* for kernel */
470 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
471 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
472 if (ret < 0) {
473 perror("send consumer channel");
474 goto error;
475 }
476
477 /* Send streams */
478 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
479 if (!stream->fd) {
480 continue;
481 }
482 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
483 lkm.u.stream.channel_key = channel->fd;
484 lkm.u.stream.stream_key = stream->fd;
485 lkm.u.stream.state = stream->state;
486 lkm.u.stream.output = channel->channel->attr.output;
487 lkm.u.stream.mmap_len = 0; /* for kernel */
488 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
489 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
490 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
491 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
492 if (ret < 0) {
493 perror("send consumer stream");
494 goto error;
495 }
496 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
497 if (ret < 0) {
498 perror("send consumer stream ancillary data");
499 goto error;
500 }
501 }
502
503 DBG("consumer channel streams sent");
504
505 return 0;
506
507 error:
508 return ret;
509 }
510
511 /*
512 * Send all stream fds of the kernel session to the consumer.
513 */
514 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
515 struct ltt_kernel_session *session)
516 {
517 int ret;
518 struct ltt_kernel_channel *chan;
519 struct lttcomm_consumer_msg lkm;
520 int sock = session->consumer_fd;
521
522 DBG("Sending metadata stream fd");
523
524 /* Extra protection. It's NOT supposed to be set to 0 at this point */
525 if (session->consumer_fd == 0) {
526 session->consumer_fd = consumer_data->cmd_sock;
527 }
528
529 if (session->metadata_stream_fd != 0) {
530 /* Send metadata channel fd */
531 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
532 lkm.u.channel.channel_key = session->metadata->fd;
533 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
534 lkm.u.channel.mmap_len = 0; /* for kernel */
535 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
536 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
537 if (ret < 0) {
538 perror("send consumer channel");
539 goto error;
540 }
541
542 /* Send metadata stream fd */
543 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
544 lkm.u.stream.channel_key = session->metadata->fd;
545 lkm.u.stream.stream_key = session->metadata_stream_fd;
546 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
547 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
548 lkm.u.stream.mmap_len = 0; /* for kernel */
549 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
550 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
551 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
552 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
553 if (ret < 0) {
554 perror("send consumer stream");
555 goto error;
556 }
557 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
558 if (ret < 0) {
559 perror("send consumer stream");
560 goto error;
561 }
562 }
563
564 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
565 ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
566 if (ret < 0) {
567 goto error;
568 }
569 }
570
571 DBG("consumer fds (metadata and channel streams) sent");
572
573 return 0;
574
575 error:
576 return ret;
577 }
578
579 /*
580 * Notify UST applications using the shm mmap futex.
581 */
582 static int notify_ust_apps(int active)
583 {
584 char *wait_shm_mmap;
585
586 DBG("Notifying applications of session daemon state: %d", active);
587
588 /* See shm.c for this call implying mmap, shm and futex calls */
589 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
590 if (wait_shm_mmap == NULL) {
591 goto error;
592 }
593
594 /* Wake waiting process */
595 futex_wait_update((int32_t *) wait_shm_mmap, active);
596
597 /* Apps notified successfully */
598 return 0;
599
600 error:
601 return -1;
602 }
603
604 /*
605 * Setup the outgoing data buffer for the response (llm) by allocating the
606 * right amount of memory and copying the original information from the lsm
607 * structure.
608 *
609 * Return total size of the buffer pointed by buf.
610 */
611 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
612 {
613 int ret, buf_size;
614
615 buf_size = size;
616
617 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
618 if (cmd_ctx->llm == NULL) {
619 perror("zmalloc");
620 ret = -ENOMEM;
621 goto error;
622 }
623
624 /* Copy common data */
625 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
626 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
627
628 cmd_ctx->llm->data_size = size;
629 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
630
631 return buf_size;
632
633 error:
634 return ret;
635 }
636
637 /*
638 * Update the kernel poll set of all channel fd available over all tracing
639 * session. Add the wakeup pipe at the end of the set.
640 */
641 static int update_kernel_poll(struct lttng_poll_event *events)
642 {
643 int ret;
644 struct ltt_session *session;
645 struct ltt_kernel_channel *channel;
646
647 DBG("Updating kernel poll set");
648
649 session_lock_list();
650 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
651 session_lock(session);
652 if (session->kernel_session == NULL) {
653 session_unlock(session);
654 continue;
655 }
656
657 cds_list_for_each_entry(channel,
658 &session->kernel_session->channel_list.head, list) {
659 /* Add channel fd to the kernel poll set */
660 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
661 if (ret < 0) {
662 session_unlock(session);
663 goto error;
664 }
665 DBG("Channel fd %d added to kernel set", channel->fd);
666 }
667 session_unlock(session);
668 }
669 session_unlock_list();
670
671 return 0;
672
673 error:
674 session_unlock_list();
675 return -1;
676 }
677
678 /*
679 * Find the channel fd from 'fd' over all tracing session. When found, check
680 * for new channel stream and send those stream fds to the kernel consumer.
681 *
682 * Useful for CPU hotplug feature.
683 */
684 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
685 {
686 int ret = 0;
687 struct ltt_session *session;
688 struct ltt_kernel_channel *channel;
689
690 DBG("Updating kernel streams for channel fd %d", fd);
691
692 session_lock_list();
693 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
694 session_lock(session);
695 if (session->kernel_session == NULL) {
696 session_unlock(session);
697 continue;
698 }
699
700 /* This is not suppose to be 0 but this is an extra security check */
701 if (session->kernel_session->consumer_fd == 0) {
702 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
703 }
704
705 cds_list_for_each_entry(channel,
706 &session->kernel_session->channel_list.head, list) {
707 if (channel->fd == fd) {
708 DBG("Channel found, updating kernel streams");
709 ret = kernel_open_channel_stream(channel);
710 if (ret < 0) {
711 goto error;
712 }
713
714 /*
715 * Have we already sent fds to the consumer? If yes, it means
716 * that tracing is started so it is safe to send our updated
717 * stream fds.
718 */
719 if (session->kernel_session->consumer_fds_sent == 1) {
720 ret = send_kconsumer_channel_streams(consumer_data,
721 session->kernel_session->consumer_fd, channel);
722 if (ret < 0) {
723 goto error;
724 }
725 }
726 goto error;
727 }
728 }
729 session_unlock(session);
730 }
731 session_unlock_list();
732 return ret;
733
734 error:
735 session_unlock(session);
736 session_unlock_list();
737 return ret;
738 }
739
740 /*
741 * For each tracing session, update newly registered apps.
742 */
743 static void update_ust_app(int app_sock)
744 {
745 struct ltt_session *sess, *stmp;
746
747 /* For all tracing session(s) */
748 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
749 if (sess->ust_session) {
750 ust_app_global_update(sess->ust_session, app_sock);
751 }
752 }
753 }
754
755 /*
756 * This thread manage event coming from the kernel.
757 *
758 * Features supported in this thread:
759 * -) CPU Hotplug
760 */
761 static void *thread_manage_kernel(void *data)
762 {
763 int ret, i, pollfd, update_poll_flag = 1;
764 uint32_t revents, nb_fd;
765 char tmp;
766 struct lttng_poll_event events;
767
768 DBG("Thread manage kernel started");
769
770 ret = create_thread_poll_set(&events, 2);
771 if (ret < 0) {
772 goto error;
773 }
774
775 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
776 if (ret < 0) {
777 goto error;
778 }
779
780 while (1) {
781 if (update_poll_flag == 1) {
782 /*
783 * Reset number of fd in the poll set. Always 2 since there is the thread
784 * quit pipe and the kernel pipe.
785 */
786 events.nb_fd = 2;
787
788 ret = update_kernel_poll(&events);
789 if (ret < 0) {
790 goto error;
791 }
792 update_poll_flag = 0;
793 }
794
795 nb_fd = LTTNG_POLL_GETNB(&events);
796
797 DBG("Thread kernel polling on %d fds", nb_fd);
798
799 /* Zeroed the poll events */
800 lttng_poll_reset(&events);
801
802 /* Poll infinite value of time */
803 ret = lttng_poll_wait(&events, -1);
804 if (ret < 0) {
805 goto error;
806 } else if (ret == 0) {
807 /* Should not happen since timeout is infinite */
808 ERR("Return value of poll is 0 with an infinite timeout.\n"
809 "This should not have happened! Continuing...");
810 continue;
811 }
812
813 for (i = 0; i < nb_fd; i++) {
814 /* Fetch once the poll data */
815 revents = LTTNG_POLL_GETEV(&events, i);
816 pollfd = LTTNG_POLL_GETFD(&events, i);
817
818 /* Thread quit pipe has been closed. Killing thread. */
819 ret = check_thread_quit_pipe(pollfd, revents);
820 if (ret) {
821 goto error;
822 }
823
824 /* Check for data on kernel pipe */
825 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
826 ret = read(kernel_poll_pipe[0], &tmp, 1);
827 update_poll_flag = 1;
828 continue;
829 } else {
830 /*
831 * New CPU detected by the kernel. Adding kernel stream to
832 * kernel session and updating the kernel consumer
833 */
834 if (revents & LPOLLIN) {
835 ret = update_kernel_stream(&kconsumer_data, pollfd);
836 if (ret < 0) {
837 continue;
838 }
839 break;
840 /*
841 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
842 * and unregister kernel stream at this point.
843 */
844 }
845 }
846 }
847 }
848
849 error:
850 DBG("Kernel thread dying");
851 close(kernel_poll_pipe[0]);
852 close(kernel_poll_pipe[1]);
853
854 lttng_poll_clean(&events);
855
856 return NULL;
857 }
858
859 /*
860 * This thread manage the consumer error sent back to the session daemon.
861 */
862 static void *thread_manage_consumer(void *data)
863 {
864 int sock = 0, i, ret, pollfd;
865 uint32_t revents, nb_fd;
866 enum lttcomm_return_code code;
867 struct lttng_poll_event events;
868 struct consumer_data *consumer_data = data;
869
870 DBG("[thread] Manage consumer started");
871
872 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
873 if (ret < 0) {
874 goto error;
875 }
876
877 /*
878 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
879 * Nothing more will be added to this poll set.
880 */
881 ret = create_thread_poll_set(&events, 2);
882 if (ret < 0) {
883 goto error;
884 }
885
886 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
887 if (ret < 0) {
888 goto error;
889 }
890
891 nb_fd = LTTNG_POLL_GETNB(&events);
892
893 /* Inifinite blocking call, waiting for transmission */
894 ret = lttng_poll_wait(&events, -1);
895 if (ret < 0) {
896 goto error;
897 }
898
899 for (i = 0; i < nb_fd; i++) {
900 /* Fetch once the poll data */
901 revents = LTTNG_POLL_GETEV(&events, i);
902 pollfd = LTTNG_POLL_GETFD(&events, i);
903
904 /* Thread quit pipe has been closed. Killing thread. */
905 ret = check_thread_quit_pipe(pollfd, revents);
906 if (ret) {
907 goto error;
908 }
909
910 /* Event on the registration socket */
911 if (pollfd == consumer_data->err_sock) {
912 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
913 ERR("consumer err socket poll error");
914 goto error;
915 }
916 }
917 }
918
919 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
920 if (sock < 0) {
921 goto error;
922 }
923
924 DBG2("Receiving code from consumer err_sock");
925
926 /* Getting status code from kconsumerd */
927 ret = lttcomm_recv_unix_sock(sock, &code,
928 sizeof(enum lttcomm_return_code));
929 if (ret <= 0) {
930 goto error;
931 }
932
933 if (code == CONSUMERD_COMMAND_SOCK_READY) {
934 consumer_data->cmd_sock =
935 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
936 if (consumer_data->cmd_sock < 0) {
937 sem_post(&consumer_data->sem);
938 PERROR("consumer connect");
939 goto error;
940 }
941 /* Signal condition to tell that the kconsumerd is ready */
942 sem_post(&consumer_data->sem);
943 DBG("consumer command socket ready");
944 } else {
945 ERR("consumer error when waiting for SOCK_READY : %s",
946 lttcomm_get_readable_code(-code));
947 goto error;
948 }
949
950 /* Remove the kconsumerd error sock since we've established a connexion */
951 ret = lttng_poll_del(&events, consumer_data->err_sock);
952 if (ret < 0) {
953 goto error;
954 }
955
956 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
957 if (ret < 0) {
958 goto error;
959 }
960
961 /* Update number of fd */
962 nb_fd = LTTNG_POLL_GETNB(&events);
963
964 /* Inifinite blocking call, waiting for transmission */
965 ret = lttng_poll_wait(&events, -1);
966 if (ret < 0) {
967 goto error;
968 }
969
970 for (i = 0; i < nb_fd; i++) {
971 /* Fetch once the poll data */
972 revents = LTTNG_POLL_GETEV(&events, i);
973 pollfd = LTTNG_POLL_GETFD(&events, i);
974
975 /* Thread quit pipe has been closed. Killing thread. */
976 ret = check_thread_quit_pipe(pollfd, revents);
977 if (ret) {
978 goto error;
979 }
980
981 /* Event on the kconsumerd socket */
982 if (pollfd == sock) {
983 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
984 ERR("consumer err socket second poll error");
985 goto error;
986 }
987 }
988 }
989
990 /* Wait for any kconsumerd error */
991 ret = lttcomm_recv_unix_sock(sock, &code,
992 sizeof(enum lttcomm_return_code));
993 if (ret <= 0) {
994 ERR("consumer closed the command socket");
995 goto error;
996 }
997
998 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
999
1000 error:
1001 DBG("consumer thread dying");
1002 close(consumer_data->err_sock);
1003 close(consumer_data->cmd_sock);
1004 close(sock);
1005
1006 unlink(consumer_data->err_unix_sock_path);
1007 unlink(consumer_data->cmd_unix_sock_path);
1008 consumer_data->pid = 0;
1009
1010 lttng_poll_clean(&events);
1011
1012 return NULL;
1013 }
1014
1015 /*
1016 * This thread manage application communication.
1017 */
1018 static void *thread_manage_apps(void *data)
1019 {
1020 int i, ret, pollfd;
1021 uint32_t revents, nb_fd;
1022 struct ust_command ust_cmd;
1023 struct lttng_poll_event events;
1024
1025 DBG("[thread] Manage application started");
1026
1027 rcu_register_thread();
1028 rcu_thread_online();
1029
1030 ret = create_thread_poll_set(&events, 2);
1031 if (ret < 0) {
1032 goto error;
1033 }
1034
1035 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1036 if (ret < 0) {
1037 goto error;
1038 }
1039
1040 while (1) {
1041 /* Zeroed the events structure */
1042 lttng_poll_reset(&events);
1043
1044 nb_fd = LTTNG_POLL_GETNB(&events);
1045
1046 DBG("Apps thread polling on %d fds", nb_fd);
1047
1048 /* Inifinite blocking call, waiting for transmission */
1049 ret = lttng_poll_wait(&events, -1);
1050 if (ret < 0) {
1051 goto error;
1052 }
1053
1054 for (i = 0; i < nb_fd; i++) {
1055 /* Fetch once the poll data */
1056 revents = LTTNG_POLL_GETEV(&events, i);
1057 pollfd = LTTNG_POLL_GETFD(&events, i);
1058
1059 /* Thread quit pipe has been closed. Killing thread. */
1060 ret = check_thread_quit_pipe(pollfd, revents);
1061 if (ret) {
1062 goto error;
1063 }
1064
1065 /* Inspect the apps cmd pipe */
1066 if (pollfd == apps_cmd_pipe[0]) {
1067 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1068 ERR("Apps command pipe error");
1069 goto error;
1070 } else if (revents & LPOLLIN) {
1071 /* Empty pipe */
1072 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1073 if (ret < 0 || ret < sizeof(ust_cmd)) {
1074 perror("read apps cmd pipe");
1075 goto error;
1076 }
1077
1078 /* Register applicaton to the session daemon */
1079 ret = ust_app_register(&ust_cmd.reg_msg,
1080 ust_cmd.sock);
1081 if (ret == -ENOMEM) {
1082 goto error;
1083 } else if (ret < 0) {
1084 break;
1085 }
1086
1087 /*
1088 * Add channel(s) and event(s) to newly registered apps
1089 * from lttng global UST domain.
1090 */
1091 update_ust_app(ust_cmd.sock);
1092
1093 ret = ustctl_register_done(ust_cmd.sock);
1094 if (ret < 0) {
1095 /*
1096 * If the registration is not possible, we simply
1097 * unregister the apps and continue
1098 */
1099 ust_app_unregister(ust_cmd.sock);
1100 } else {
1101 /*
1102 * We just need here to monitor the close of the UST
1103 * socket and poll set monitor those by default.
1104 */
1105 ret = lttng_poll_add(&events, ust_cmd.sock, 0);
1106 if (ret < 0) {
1107 goto error;
1108 }
1109
1110 DBG("Apps with sock %d added to poll set",
1111 ust_cmd.sock);
1112 }
1113
1114 break;
1115 }
1116 } else {
1117 /*
1118 * At this point, we know that a registered application made
1119 * the event at poll_wait.
1120 */
1121 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1122 /* Removing from the poll set */
1123 ret = lttng_poll_del(&events, pollfd);
1124 if (ret < 0) {
1125 goto error;
1126 }
1127
1128 /* Socket closed on remote end. */
1129 ust_app_unregister(pollfd);
1130 break;
1131 }
1132 }
1133 }
1134 }
1135
1136 error:
1137 DBG("Application communication apps dying");
1138 close(apps_cmd_pipe[0]);
1139 close(apps_cmd_pipe[1]);
1140
1141 lttng_poll_clean(&events);
1142
1143 rcu_thread_offline();
1144 rcu_unregister_thread();
1145 return NULL;
1146 }
1147
1148 /*
1149 * Dispatch request from the registration threads to the application
1150 * communication thread.
1151 */
1152 static void *thread_dispatch_ust_registration(void *data)
1153 {
1154 int ret;
1155 struct cds_wfq_node *node;
1156 struct ust_command *ust_cmd = NULL;
1157
1158 DBG("[thread] Dispatch UST command started");
1159
1160 while (!dispatch_thread_exit) {
1161 /* Atomically prepare the queue futex */
1162 futex_nto1_prepare(&ust_cmd_queue.futex);
1163
1164 do {
1165 /* Dequeue command for registration */
1166 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1167 if (node == NULL) {
1168 DBG("Woken up but nothing in the UST command queue");
1169 /* Continue thread execution */
1170 break;
1171 }
1172
1173 ust_cmd = caa_container_of(node, struct ust_command, node);
1174
1175 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1176 " gid:%d sock:%d name:%s (version %d.%d)",
1177 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1178 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1179 ust_cmd->sock, ust_cmd->reg_msg.name,
1180 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1181 /*
1182 * Inform apps thread of the new application registration. This
1183 * call is blocking so we can be assured that the data will be read
1184 * at some point in time or wait to the end of the world :)
1185 */
1186 ret = write(apps_cmd_pipe[1], ust_cmd,
1187 sizeof(struct ust_command));
1188 if (ret < 0) {
1189 perror("write apps cmd pipe");
1190 if (errno == EBADF) {
1191 /*
1192 * We can't inform the application thread to process
1193 * registration. We will exit or else application
1194 * registration will not occur and tracing will never
1195 * start.
1196 */
1197 goto error;
1198 }
1199 }
1200 free(ust_cmd);
1201 } while (node != NULL);
1202
1203 /* Futex wait on queue. Blocking call on futex() */
1204 futex_nto1_wait(&ust_cmd_queue.futex);
1205 }
1206
1207 error:
1208 DBG("Dispatch thread dying");
1209 return NULL;
1210 }
1211
1212 /*
1213 * This thread manage application registration.
1214 */
1215 static void *thread_registration_apps(void *data)
1216 {
1217 int sock = 0, i, ret, pollfd;
1218 uint32_t revents, nb_fd;
1219 struct lttng_poll_event events;
1220 /*
1221 * Get allocated in this thread, enqueued to a global queue, dequeued and
1222 * freed in the manage apps thread.
1223 */
1224 struct ust_command *ust_cmd = NULL;
1225
1226 DBG("[thread] Manage application registration started");
1227
1228 ret = lttcomm_listen_unix_sock(apps_sock);
1229 if (ret < 0) {
1230 goto error;
1231 }
1232
1233 /*
1234 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1235 * more will be added to this poll set.
1236 */
1237 ret = create_thread_poll_set(&events, 2);
1238 if (ret < 0) {
1239 goto error;
1240 }
1241
1242 /* Add the application registration socket */
1243 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1244 if (ret < 0) {
1245 goto error;
1246 }
1247
1248 /* Notify all applications to register */
1249 ret = notify_ust_apps(1);
1250 if (ret < 0) {
1251 ERR("Failed to notify applications or create the wait shared memory.\n"
1252 "Execution continues but there might be problem for already\n"
1253 "running applications that wishes to register.");
1254 }
1255
1256 while (1) {
1257 DBG("Accepting application registration");
1258
1259 nb_fd = LTTNG_POLL_GETNB(&events);
1260
1261 /* Inifinite blocking call, waiting for transmission */
1262 ret = lttng_poll_wait(&events, -1);
1263 if (ret < 0) {
1264 goto error;
1265 }
1266
1267 for (i = 0; i < nb_fd; i++) {
1268 /* Fetch once the poll data */
1269 revents = LTTNG_POLL_GETEV(&events, i);
1270 pollfd = LTTNG_POLL_GETFD(&events, i);
1271
1272 /* Thread quit pipe has been closed. Killing thread. */
1273 ret = check_thread_quit_pipe(pollfd, revents);
1274 if (ret) {
1275 goto error;
1276 }
1277
1278 /* Event on the registration socket */
1279 if (pollfd == apps_sock) {
1280 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1281 ERR("Register apps socket poll error");
1282 goto error;
1283 } else if (revents & LPOLLIN) {
1284 sock = lttcomm_accept_unix_sock(apps_sock);
1285 if (sock < 0) {
1286 goto error;
1287 }
1288
1289 /* Create UST registration command for enqueuing */
1290 ust_cmd = zmalloc(sizeof(struct ust_command));
1291 if (ust_cmd == NULL) {
1292 perror("ust command zmalloc");
1293 goto error;
1294 }
1295
1296 /*
1297 * Using message-based transmissions to ensure we don't
1298 * have to deal with partially received messages.
1299 */
1300 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1301 sizeof(struct ust_register_msg));
1302 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1303 if (ret < 0) {
1304 perror("lttcomm_recv_unix_sock register apps");
1305 } else {
1306 ERR("Wrong size received on apps register");
1307 }
1308 free(ust_cmd);
1309 close(sock);
1310 continue;
1311 }
1312
1313 ust_cmd->sock = sock;
1314
1315 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1316 " gid:%d sock:%d name:%s (version %d.%d)",
1317 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1318 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1319 ust_cmd->sock, ust_cmd->reg_msg.name,
1320 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1321
1322 /*
1323 * Lock free enqueue the registration request. The red pill
1324 * has been taken! This apps will be part of the *system*.
1325 */
1326 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1327
1328 /*
1329 * Wake the registration queue futex. Implicit memory
1330 * barrier with the exchange in cds_wfq_enqueue.
1331 */
1332 futex_nto1_wake(&ust_cmd_queue.futex);
1333 }
1334 }
1335 }
1336 }
1337
1338 error:
1339 DBG("UST Registration thread dying");
1340
1341 /* Notify that the registration thread is gone */
1342 notify_ust_apps(0);
1343
1344 close(apps_sock);
1345 close(sock);
1346 unlink(apps_unix_sock_path);
1347
1348 lttng_poll_clean(&events);
1349
1350 return NULL;
1351 }
1352
1353 /*
1354 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1355 * exec or it will fails.
1356 */
1357 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1358 {
1359 int ret;
1360 struct timespec timeout;
1361
1362 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1363 timeout.tv_nsec = 0;
1364
1365 /* Setup semaphore */
1366 ret = sem_init(&consumer_data->sem, 0, 0);
1367 if (ret < 0) {
1368 PERROR("sem_init consumer semaphore");
1369 goto error;
1370 }
1371
1372 ret = pthread_create(&consumer_data->thread, NULL,
1373 thread_manage_consumer, consumer_data);
1374 if (ret != 0) {
1375 PERROR("pthread_create consumer");
1376 ret = -1;
1377 goto error;
1378 }
1379
1380 /* Get time for sem_timedwait absolute timeout */
1381 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1382 if (ret < 0) {
1383 PERROR("clock_gettime spawn consumer");
1384 /* Infinite wait for the kconsumerd thread to be ready */
1385 ret = sem_wait(&consumer_data->sem);
1386 } else {
1387 /* Normal timeout if the gettime was successful */
1388 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1389 ret = sem_timedwait(&consumer_data->sem, &timeout);
1390 }
1391
1392 if (ret < 0) {
1393 if (errno == ETIMEDOUT) {
1394 /*
1395 * Call has timed out so we kill the kconsumerd_thread and return
1396 * an error.
1397 */
1398 ERR("The consumer thread was never ready. Killing it");
1399 ret = pthread_cancel(consumer_data->thread);
1400 if (ret < 0) {
1401 PERROR("pthread_cancel consumer thread");
1402 }
1403 } else {
1404 PERROR("semaphore wait failed consumer thread");
1405 }
1406 goto error;
1407 }
1408
1409 pthread_mutex_lock(&consumer_data->pid_mutex);
1410 if (consumer_data->pid == 0) {
1411 ERR("Kconsumerd did not start");
1412 pthread_mutex_unlock(&consumer_data->pid_mutex);
1413 goto error;
1414 }
1415 pthread_mutex_unlock(&consumer_data->pid_mutex);
1416
1417 return 0;
1418
1419 error:
1420 return ret;
1421 }
1422
1423 /*
1424 * Join consumer thread
1425 */
1426 static int join_consumer_thread(struct consumer_data *consumer_data)
1427 {
1428 void *status;
1429 int ret;
1430
1431 if (consumer_data->pid != 0) {
1432 ret = kill(consumer_data->pid, SIGTERM);
1433 if (ret) {
1434 ERR("Error killing consumer daemon");
1435 return ret;
1436 }
1437 return pthread_join(consumer_data->thread, &status);
1438 } else {
1439 return 0;
1440 }
1441 }
1442
1443 /*
1444 * Fork and exec a consumer daemon (consumerd).
1445 *
1446 * Return pid if successful else -1.
1447 */
1448 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1449 {
1450 int ret;
1451 pid_t pid;
1452 const char *verbosity;
1453
1454 DBG("Spawning consumerd");
1455
1456 pid = fork();
1457 if (pid == 0) {
1458 /*
1459 * Exec consumerd.
1460 */
1461 if (opt_verbose > 1 || opt_verbose_consumer) {
1462 verbosity = "--verbose";
1463 } else {
1464 verbosity = "--quiet";
1465 }
1466 switch (consumer_data->type) {
1467 case LTTNG_CONSUMER_KERNEL:
1468 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1469 "lttng-consumerd", verbosity, "-k", NULL);
1470 break;
1471 case LTTNG_CONSUMER_UST:
1472 execl(INSTALL_BIN_PATH "/lttng-consumerd",
1473 "lttng-consumerd", verbosity, "-u", NULL);
1474 break;
1475 default:
1476 perror("unknown consumer type");
1477 exit(EXIT_FAILURE);
1478 }
1479 if (errno != 0) {
1480 perror("kernel start consumer exec");
1481 }
1482 exit(EXIT_FAILURE);
1483 } else if (pid > 0) {
1484 ret = pid;
1485 } else {
1486 perror("start consumer fork");
1487 ret = -errno;
1488 }
1489 return ret;
1490 }
1491
1492 /*
1493 * Spawn the consumerd daemon and session daemon thread.
1494 */
1495 static int start_consumerd(struct consumer_data *consumer_data)
1496 {
1497 int ret;
1498
1499 pthread_mutex_lock(&consumer_data->pid_mutex);
1500 if (consumer_data->pid != 0) {
1501 pthread_mutex_unlock(&consumer_data->pid_mutex);
1502 goto end;
1503 }
1504
1505 ret = spawn_consumerd(consumer_data);
1506 if (ret < 0) {
1507 ERR("Spawning consumerd failed");
1508 pthread_mutex_unlock(&consumer_data->pid_mutex);
1509 goto error;
1510 }
1511
1512 /* Setting up the consumer_data pid */
1513 consumer_data->pid = ret;
1514 DBG2("Consumer pid %d", consumer_data->pid);
1515 pthread_mutex_unlock(&consumer_data->pid_mutex);
1516
1517 DBG2("Spawning consumer control thread");
1518 ret = spawn_consumer_thread(consumer_data);
1519 if (ret < 0) {
1520 ERR("Fatal error spawning consumer control thread");
1521 goto error;
1522 }
1523
1524 end:
1525 return 0;
1526
1527 error:
1528 return ret;
1529 }
1530
1531 /*
1532 * modprobe_kernel_modules
1533 */
1534 static int modprobe_kernel_modules(void)
1535 {
1536 int ret = 0, i;
1537 char modprobe[256];
1538
1539 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1540 ret = snprintf(modprobe, sizeof(modprobe),
1541 "/sbin/modprobe %s%s",
1542 kernel_modules_list[i].required ? "" : "-q ",
1543 kernel_modules_list[i].name);
1544 if (ret < 0) {
1545 perror("snprintf modprobe");
1546 goto error;
1547 }
1548 modprobe[sizeof(modprobe) - 1] = '\0';
1549 ret = system(modprobe);
1550 if (ret == -1) {
1551 ERR("Unable to launch modprobe for module %s",
1552 kernel_modules_list[i].name);
1553 } else if (kernel_modules_list[i].required
1554 && WEXITSTATUS(ret) != 0) {
1555 ERR("Unable to load module %s",
1556 kernel_modules_list[i].name);
1557 } else {
1558 DBG("Modprobe successfully %s",
1559 kernel_modules_list[i].name);
1560 }
1561 }
1562
1563 error:
1564 return ret;
1565 }
1566
1567 /*
1568 * mount_debugfs
1569 */
1570 static int mount_debugfs(char *path)
1571 {
1572 int ret;
1573 char *type = "debugfs";
1574
1575 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1576 if (ret < 0) {
1577 PERROR("Cannot create debugfs path");
1578 goto error;
1579 }
1580
1581 ret = mount(type, path, type, 0, NULL);
1582 if (ret < 0) {
1583 PERROR("Cannot mount debugfs");
1584 goto error;
1585 }
1586
1587 DBG("Mounted debugfs successfully at %s", path);
1588
1589 error:
1590 return ret;
1591 }
1592
1593 /*
1594 * Setup necessary data for kernel tracer action.
1595 */
1596 static void init_kernel_tracer(void)
1597 {
1598 int ret;
1599 char *proc_mounts = "/proc/mounts";
1600 char line[256];
1601 char *debugfs_path = NULL, *lttng_path = NULL;
1602 FILE *fp;
1603
1604 /* Detect debugfs */
1605 fp = fopen(proc_mounts, "r");
1606 if (fp == NULL) {
1607 ERR("Unable to probe %s", proc_mounts);
1608 goto error;
1609 }
1610
1611 while (fgets(line, sizeof(line), fp) != NULL) {
1612 if (strstr(line, "debugfs") != NULL) {
1613 /* Remove first string */
1614 strtok(line, " ");
1615 /* Dup string here so we can reuse line later on */
1616 debugfs_path = strdup(strtok(NULL, " "));
1617 DBG("Got debugfs path : %s", debugfs_path);
1618 break;
1619 }
1620 }
1621
1622 fclose(fp);
1623
1624 /* Mount debugfs if needded */
1625 if (debugfs_path == NULL) {
1626 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1627 if (ret < 0) {
1628 perror("asprintf debugfs path");
1629 goto error;
1630 }
1631 ret = mount_debugfs(debugfs_path);
1632 if (ret < 0) {
1633 perror("Cannot mount debugfs");
1634 goto error;
1635 }
1636 }
1637
1638 /* Modprobe lttng kernel modules */
1639 ret = modprobe_kernel_modules();
1640 if (ret < 0) {
1641 goto error;
1642 }
1643
1644 /* Setup lttng kernel path */
1645 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1646 if (ret < 0) {
1647 perror("asprintf lttng path");
1648 goto error;
1649 }
1650
1651 /* Open debugfs lttng */
1652 kernel_tracer_fd = open(lttng_path, O_RDWR);
1653 if (kernel_tracer_fd < 0) {
1654 DBG("Failed to open %s", lttng_path);
1655 goto error;
1656 }
1657
1658 free(lttng_path);
1659 free(debugfs_path);
1660 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1661 return;
1662
1663 error:
1664 if (lttng_path) {
1665 free(lttng_path);
1666 }
1667 if (debugfs_path) {
1668 free(debugfs_path);
1669 }
1670 WARN("No kernel tracer available");
1671 kernel_tracer_fd = 0;
1672 return;
1673 }
1674
1675 /*
1676 * Init tracing by creating trace directory and sending fds kernel consumer.
1677 */
1678 static int init_kernel_tracing(struct ltt_kernel_session *session)
1679 {
1680 int ret = 0;
1681
1682 if (session->consumer_fds_sent == 0) {
1683 /*
1684 * Assign default kernel consumer socket if no consumer assigned to the
1685 * kernel session. At this point, it's NOT suppose to be 0 but this is
1686 * an extra security check.
1687 */
1688 if (session->consumer_fd == 0) {
1689 session->consumer_fd = kconsumer_data.cmd_sock;
1690 }
1691
1692 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1693 if (ret < 0) {
1694 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1695 goto error;
1696 }
1697
1698 session->consumer_fds_sent = 1;
1699 }
1700
1701 error:
1702 return ret;
1703 }
1704
1705 /*
1706 * Create an UST session and add it to the session ust list.
1707 */
1708 static int create_ust_session(struct ltt_session *session,
1709 struct lttng_domain *domain)
1710 {
1711 int ret;
1712 unsigned int uid;
1713 struct ltt_ust_session *lus = NULL;
1714
1715 switch (domain->type) {
1716 case LTTNG_DOMAIN_UST:
1717 break;
1718 default:
1719 ret = LTTCOMM_UNKNOWN_DOMAIN;
1720 goto error;
1721 }
1722
1723 DBG("Creating UST session");
1724
1725 session_lock_list();
1726 uid = session_list_ptr->count;
1727 session_unlock_list();
1728
1729 lus = trace_ust_create_session(session->path, uid, domain);
1730 if (lus == NULL) {
1731 ret = LTTCOMM_UST_SESS_FAIL;
1732 goto error;
1733 }
1734
1735 ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1736 geteuid(), allowed_group());
1737 if (ret < 0) {
1738 if (ret != -EEXIST) {
1739 ERR("Trace directory creation error");
1740 ret = LTTCOMM_UST_SESS_FAIL;
1741 goto error;
1742 }
1743 }
1744
1745 /* The domain type dictate different actions on session creation */
1746 switch (domain->type) {
1747 case LTTNG_DOMAIN_UST:
1748 /* No ustctl for the global UST domain */
1749 break;
1750 default:
1751 ERR("Unknown UST domain on create session %d", domain->type);
1752 goto error;
1753 }
1754 session->ust_session = lus;
1755
1756 return LTTCOMM_OK;
1757
1758 error:
1759 free(lus);
1760 return ret;
1761 }
1762
1763 /*
1764 * Create a kernel tracer session then create the default channel.
1765 */
1766 static int create_kernel_session(struct ltt_session *session)
1767 {
1768 int ret;
1769
1770 DBG("Creating kernel session");
1771
1772 ret = kernel_create_session(session, kernel_tracer_fd);
1773 if (ret < 0) {
1774 ret = LTTCOMM_KERN_SESS_FAIL;
1775 goto error;
1776 }
1777
1778 /* Set kernel consumer socket fd */
1779 if (kconsumer_data.cmd_sock) {
1780 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1781 }
1782
1783 ret = mkdir_recursive(session->kernel_session->trace_path,
1784 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1785 if (ret < 0) {
1786 if (ret != -EEXIST) {
1787 ERR("Trace directory creation error");
1788 goto error;
1789 }
1790 }
1791
1792 error:
1793 return ret;
1794 }
1795
1796 /*
1797 * Using the session list, filled a lttng_session array to send back to the
1798 * client for session listing.
1799 *
1800 * The session list lock MUST be acquired before calling this function. Use
1801 * session_lock_list() and session_unlock_list().
1802 */
1803 static void list_lttng_sessions(struct lttng_session *sessions)
1804 {
1805 int i = 0;
1806 struct ltt_session *session;
1807
1808 DBG("Getting all available session");
1809 /*
1810 * Iterate over session list and append data after the control struct in
1811 * the buffer.
1812 */
1813 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1814 strncpy(sessions[i].path, session->path, PATH_MAX);
1815 sessions[i].path[PATH_MAX - 1] = '\0';
1816 strncpy(sessions[i].name, session->name, NAME_MAX);
1817 sessions[i].name[NAME_MAX - 1] = '\0';
1818 sessions[i].enabled = session->enabled;
1819 i++;
1820 }
1821 }
1822
1823 /*
1824 * Fill lttng_channel array of all channels.
1825 */
1826 static void list_lttng_channels(int domain, struct ltt_session *session,
1827 struct lttng_channel *channels)
1828 {
1829 int i = 0;
1830 struct ltt_kernel_channel *kchan;
1831
1832 DBG("Listing channels for session %s", session->name);
1833
1834 switch (domain) {
1835 case LTTNG_DOMAIN_KERNEL:
1836 /* Kernel channels */
1837 if (session->kernel_session != NULL) {
1838 cds_list_for_each_entry(kchan,
1839 &session->kernel_session->channel_list.head, list) {
1840 /* Copy lttng_channel struct to array */
1841 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1842 channels[i].enabled = kchan->enabled;
1843 i++;
1844 }
1845 }
1846 break;
1847 case LTTNG_DOMAIN_UST:
1848 {
1849 struct cds_lfht_iter iter;
1850 struct ltt_ust_channel *uchan;
1851
1852 cds_lfht_for_each_entry(session->ust_session->domain_global.channels,
1853 &iter, uchan, node) {
1854 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
1855 channels[i].attr.overwrite = uchan->attr.overwrite;
1856 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
1857 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
1858 channels[i].attr.switch_timer_interval =
1859 uchan->attr.switch_timer_interval;
1860 channels[i].attr.read_timer_interval =
1861 uchan->attr.read_timer_interval;
1862 channels[i].attr.output = uchan->attr.output;
1863 }
1864 break;
1865 }
1866 default:
1867 break;
1868 }
1869 }
1870
1871 /*
1872 * Create a list of ust global domain events.
1873 */
1874 static int list_lttng_ust_global_events(char *channel_name,
1875 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
1876 {
1877 int i = 0, ret = 0;
1878 unsigned int nb_event = 0;
1879 struct cds_lfht_iter iter;
1880 struct ltt_ust_channel *uchan;
1881 struct ltt_ust_event *uevent;
1882 struct lttng_event *tmp;
1883
1884 DBG("Listing UST global events for channel %s", channel_name);
1885
1886 rcu_read_lock();
1887
1888 /* Count events in all channels */
1889 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1890 nb_event += hashtable_get_count(uchan->events);
1891 }
1892
1893 if (nb_event == 0) {
1894 ret = nb_event;
1895 goto error;
1896 }
1897
1898 DBG3("Listing UST global %d events", nb_event);
1899
1900 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
1901 if (tmp == NULL) {
1902 ret = -LTTCOMM_FATAL;
1903 goto error;
1904 }
1905
1906 cds_lfht_for_each_entry(ust_global->channels, &iter, uchan, node) {
1907 cds_lfht_for_each_entry(uchan->events, &iter, uevent, node) {
1908 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
1909 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1910 tmp[i].enabled = uevent->enabled;
1911 switch (uevent->attr.instrumentation) {
1912 case LTTNG_UST_TRACEPOINT:
1913 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
1914 break;
1915 case LTTNG_UST_PROBE:
1916 tmp[i].type = LTTNG_EVENT_PROBE;
1917 break;
1918 case LTTNG_UST_FUNCTION:
1919 tmp[i].type = LTTNG_EVENT_FUNCTION;
1920 break;
1921 }
1922 i++;
1923 }
1924 }
1925
1926 ret = nb_event;
1927 *events = tmp;
1928
1929 error:
1930 rcu_read_unlock();
1931 return ret;
1932 }
1933
1934 /*
1935 * Fill lttng_event array of all kernel events in the channel.
1936 */
1937 static int list_lttng_kernel_events(char *channel_name,
1938 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
1939 {
1940 int i = 0, ret;
1941 unsigned int nb_event;
1942 struct ltt_kernel_event *event;
1943 struct ltt_kernel_channel *kchan;
1944
1945 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
1946 if (kchan == NULL) {
1947 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1948 goto error;
1949 }
1950
1951 nb_event = kchan->event_count;
1952
1953 DBG("Listing events for channel %s", kchan->channel->name);
1954
1955 if (nb_event == 0) {
1956 ret = nb_event;
1957 goto error;
1958 }
1959
1960 *events = zmalloc(nb_event * sizeof(struct lttng_event));
1961 if (*events == NULL) {
1962 ret = LTTCOMM_FATAL;
1963 goto error;
1964 }
1965
1966 /* Kernel channels */
1967 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1968 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1969 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1970 (*events)[i].enabled = event->enabled;
1971 switch (event->event->instrumentation) {
1972 case LTTNG_KERNEL_TRACEPOINT:
1973 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
1974 break;
1975 case LTTNG_KERNEL_KPROBE:
1976 case LTTNG_KERNEL_KRETPROBE:
1977 (*events)[i].type = LTTNG_EVENT_PROBE;
1978 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
1979 sizeof(struct lttng_kernel_kprobe));
1980 break;
1981 case LTTNG_KERNEL_FUNCTION:
1982 (*events)[i].type = LTTNG_EVENT_FUNCTION;
1983 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
1984 sizeof(struct lttng_kernel_function));
1985 break;
1986 case LTTNG_KERNEL_NOOP:
1987 (*events)[i].type = LTTNG_EVENT_NOOP;
1988 break;
1989 case LTTNG_KERNEL_SYSCALL:
1990 (*events)[i].type = LTTNG_EVENT_SYSCALL;
1991 break;
1992 case LTTNG_KERNEL_ALL:
1993 assert(0);
1994 break;
1995 }
1996 i++;
1997 }
1998
1999 return nb_event;
2000
2001 error:
2002 return ret;
2003 }
2004
2005 /*
2006 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2007 */
2008 static int cmd_disable_channel(struct ltt_session *session,
2009 int domain, char *channel_name)
2010 {
2011 int ret;
2012
2013 switch (domain) {
2014 case LTTNG_DOMAIN_KERNEL:
2015 ret = channel_kernel_disable(session->kernel_session,
2016 channel_name);
2017 if (ret != LTTCOMM_OK) {
2018 goto error;
2019 }
2020
2021 kernel_wait_quiescent(kernel_tracer_fd);
2022 break;
2023 case LTTNG_DOMAIN_UST_PID:
2024 break;
2025 default:
2026 ret = LTTCOMM_UNKNOWN_DOMAIN;
2027 goto error;
2028 }
2029
2030 ret = LTTCOMM_OK;
2031
2032 error:
2033 return ret;
2034 }
2035
2036 /*
2037 * Copy channel from attributes and set it in the application channel list.
2038 */
2039 /*
2040 static int copy_ust_channel_to_app(struct ltt_ust_session *usess,
2041 struct lttng_channel *attr, struct ust_app *app)
2042 {
2043 int ret;
2044 struct ltt_ust_channel *uchan, *new_chan;
2045
2046 uchan = trace_ust_get_channel_by_key(usess->channels, attr->name);
2047 if (uchan == NULL) {
2048 ret = LTTCOMM_FATAL;
2049 goto error;
2050 }
2051
2052 new_chan = trace_ust_create_channel(attr, usess->path);
2053 if (new_chan == NULL) {
2054 PERROR("malloc ltt_ust_channel");
2055 ret = LTTCOMM_FATAL;
2056 goto error;
2057 }
2058
2059 ret = channel_ust_copy(new_chan, uchan);
2060 if (ret < 0) {
2061 ret = LTTCOMM_FATAL;
2062 goto error;
2063 }
2064
2065 error:
2066 return ret;
2067 }
2068 */
2069
2070 /*
2071 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2072 */
2073 static int cmd_enable_channel(struct ltt_session *session,
2074 struct lttng_domain *domain, struct lttng_channel *attr)
2075 {
2076 int ret;
2077 struct ltt_ust_session *usess = session->ust_session;
2078
2079 DBG("Enabling channel %s for session %s", attr->name, session->name);
2080
2081 switch (domain->type) {
2082 case LTTNG_DOMAIN_KERNEL:
2083 {
2084 struct ltt_kernel_channel *kchan;
2085
2086 kchan = trace_kernel_get_channel_by_name(attr->name,
2087 session->kernel_session);
2088 if (kchan == NULL) {
2089 ret = channel_kernel_create(session->kernel_session,
2090 attr, kernel_poll_pipe[1]);
2091 } else {
2092 ret = channel_kernel_enable(session->kernel_session, kchan);
2093 }
2094
2095 if (ret != LTTCOMM_OK) {
2096 goto error;
2097 }
2098
2099 kernel_wait_quiescent(kernel_tracer_fd);
2100 break;
2101 }
2102 case LTTNG_DOMAIN_UST:
2103 {
2104 struct ltt_ust_channel *uchan;
2105
2106 DBG2("Enabling channel for LTTNG_DOMAIN_UST");
2107
2108 /* Get channel in global UST domain HT */
2109 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2110 attr->name);
2111 if (uchan == NULL) {
2112 uchan = trace_ust_create_channel(attr, usess->pathname);
2113 if (uchan == NULL) {
2114 ret = LTTCOMM_UST_CHAN_FAIL;
2115 goto error;
2116 }
2117
2118 rcu_read_lock();
2119 hashtable_add_unique(usess->domain_global.channels, &uchan->node);
2120 rcu_read_unlock();
2121 DBG2("UST channel %s added to global domain HT", attr->name);
2122 } else {
2123 ret = LTTCOMM_UST_CHAN_EXIST;
2124 goto error;
2125 }
2126
2127 /* Add channel to all registered applications */
2128 ret = ust_app_create_channel_all(usess, uchan);
2129 if (ret != 0) {
2130 goto error;
2131 }
2132
2133 uchan->enabled = 1;
2134
2135 break;
2136 }
2137 case LTTNG_DOMAIN_UST_PID:
2138 {
2139 /*
2140 int sock;
2141 struct ltt_ust_channel *uchan;
2142 struct ltt_ust_session *usess;
2143 struct ust_app *app;
2144
2145 usess = trace_ust_get_session_by_pid(&session->ust_session_list,
2146 domain->attr.pid);
2147 if (usess == NULL) {
2148 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2149 goto error;
2150 }
2151
2152 app = ust_app_get_by_pid(domain->attr.pid);
2153 if (app == NULL) {
2154 ret = LTTCOMM_APP_NOT_FOUND;
2155 goto error;
2156 }
2157 sock = app->sock;
2158
2159 uchan = trace_ust_get_channel_by_name(attr->name, usess);
2160 if (uchan == NULL) {
2161 ret = channel_ust_create(usess, attr, sock);
2162 } else {
2163 ret = channel_ust_enable(usess, uchan, sock);
2164 }
2165
2166 if (ret != LTTCOMM_OK) {
2167 goto error;
2168 }
2169
2170 ret = copy_ust_channel_to_app(usess, attr, app);
2171 if (ret != LTTCOMM_OK) {
2172 goto error;
2173 }
2174
2175 DBG("UST channel %s created for app sock %d with pid %d",
2176 attr->name, app->sock, domain->attr.pid);
2177 */
2178 ret = LTTCOMM_NOT_IMPLEMENTED;
2179 goto error;
2180 }
2181 default:
2182 ret = LTTCOMM_UNKNOWN_DOMAIN;
2183 goto error;
2184 }
2185
2186 ret = LTTCOMM_OK;
2187
2188 error:
2189 return ret;
2190 }
2191
2192 /*
2193 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2194 */
2195 static int cmd_disable_event(struct ltt_session *session, int domain,
2196 char *channel_name, char *event_name)
2197 {
2198 int ret;
2199
2200 switch (domain) {
2201 case LTTNG_DOMAIN_KERNEL:
2202 {
2203 struct ltt_kernel_channel *kchan;
2204
2205 kchan = trace_kernel_get_channel_by_name(channel_name,
2206 session->kernel_session);
2207 if (kchan == NULL) {
2208 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2209 goto error;
2210 }
2211
2212 ret = event_kernel_disable_tracepoint(session->kernel_session, kchan, event_name);
2213 if (ret != LTTCOMM_OK) {
2214 goto error;
2215 }
2216
2217 kernel_wait_quiescent(kernel_tracer_fd);
2218 break;
2219 }
2220 case LTTNG_DOMAIN_UST:
2221 case LTTNG_DOMAIN_UST_EXEC_NAME:
2222 case LTTNG_DOMAIN_UST_PID:
2223 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2224 default:
2225 /* TODO: Other UST domains */
2226 ret = LTTCOMM_NOT_IMPLEMENTED;
2227 goto error;
2228 }
2229
2230 ret = LTTCOMM_OK;
2231
2232 error:
2233 return ret;
2234 }
2235
2236 /*
2237 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2238 */
2239 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2240 char *channel_name)
2241 {
2242 int ret;
2243 struct ltt_kernel_channel *kchan;
2244
2245 switch (domain) {
2246 case LTTNG_DOMAIN_KERNEL:
2247 kchan = trace_kernel_get_channel_by_name(channel_name,
2248 session->kernel_session);
2249 if (kchan == NULL) {
2250 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2251 goto error;
2252 }
2253
2254 ret = event_kernel_disable_all(session->kernel_session, kchan);
2255 if (ret != LTTCOMM_OK) {
2256 goto error;
2257 }
2258
2259 kernel_wait_quiescent(kernel_tracer_fd);
2260 break;
2261 default:
2262 /* TODO: Userspace tracing */
2263 ret = LTTCOMM_NOT_IMPLEMENTED;
2264 goto error;
2265 }
2266
2267 ret = LTTCOMM_OK;
2268
2269 error:
2270 return ret;
2271 }
2272
2273 /*
2274 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2275 */
2276 static int cmd_add_context(struct ltt_session *session, int domain,
2277 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2278 {
2279 int ret;
2280
2281 switch (domain) {
2282 case LTTNG_DOMAIN_KERNEL:
2283 /* Add kernel context to kernel tracer */
2284 ret = context_kernel_add(session->kernel_session, ctx,
2285 event_name, channel_name);
2286 if (ret != LTTCOMM_OK) {
2287 goto error;
2288 }
2289 break;
2290 case LTTNG_DOMAIN_UST:
2291 {
2292 /*
2293 struct ltt_ust_session *usess;
2294
2295 cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
2296 ret = context_ust_add(usess, ctx,
2297 event_name, channel_name, domain);
2298 if (ret != LTTCOMM_OK) {
2299 goto error;
2300 }
2301 }
2302 break;
2303 */
2304 }
2305 default:
2306 /* TODO: UST other domains */
2307 ret = LTTCOMM_NOT_IMPLEMENTED;
2308 goto error;
2309 }
2310
2311 ret = LTTCOMM_OK;
2312
2313 error:
2314 return ret;
2315 }
2316
2317 /*
2318 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2319 */
2320 static int cmd_enable_event(struct ltt_session *session, int domain,
2321 char *channel_name, struct lttng_event *event)
2322 {
2323 int ret;
2324 struct lttng_channel *attr;
2325 struct ltt_ust_session *usess = session->ust_session;
2326
2327 switch (domain) {
2328 case LTTNG_DOMAIN_KERNEL:
2329 {
2330 struct ltt_kernel_channel *kchan;
2331
2332 kchan = trace_kernel_get_channel_by_name(channel_name,
2333 session->kernel_session);
2334 if (kchan == NULL) {
2335 attr = channel_new_default_attr(domain);
2336 if (attr == NULL) {
2337 ret = LTTCOMM_FATAL;
2338 goto error;
2339 }
2340 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2341
2342 /* This call will notify the kernel thread */
2343 ret = channel_kernel_create(session->kernel_session,
2344 attr, kernel_poll_pipe[1]);
2345 if (ret != LTTCOMM_OK) {
2346 goto error;
2347 }
2348 }
2349
2350 /* Get the newly created kernel channel pointer */
2351 kchan = trace_kernel_get_channel_by_name(channel_name,
2352 session->kernel_session);
2353 if (kchan == NULL) {
2354 /* This sould not happen... */
2355 ret = LTTCOMM_FATAL;
2356 goto error;
2357 }
2358
2359 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2360 event);
2361 if (ret != LTTCOMM_OK) {
2362 goto error;
2363 }
2364
2365 kernel_wait_quiescent(kernel_tracer_fd);
2366 break;
2367 }
2368 case LTTNG_DOMAIN_UST:
2369 {
2370 struct ltt_ust_channel *uchan;
2371 struct ltt_ust_event *uevent;
2372
2373 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2374 channel_name);
2375 if (uchan == NULL) {
2376 /* TODO: Create default channel */
2377 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2378 goto error;
2379 }
2380
2381 uevent = trace_ust_find_event_by_name(uchan->events, event->name);
2382 if (uevent == NULL) {
2383 uevent = trace_ust_create_event(event);
2384 if (uevent == NULL) {
2385 ret = LTTCOMM_FATAL;
2386 goto error;
2387 }
2388
2389 }
2390
2391 ret = ust_app_create_event_all(usess, uchan, uevent);
2392 if (ret < 0) {
2393 ret = LTTCOMM_UST_ENABLE_FAIL;
2394 goto error;
2395 }
2396
2397 /* Add ltt ust event to channel */
2398 rcu_read_lock();
2399 hashtable_add_unique(uchan->events, &uevent->node);
2400 rcu_read_unlock();
2401
2402 uevent->enabled = 1;
2403
2404 DBG3("UST ltt event %s added to channel %s", uevent->attr.name,
2405 uchan->name);
2406 break;
2407 }
2408 case LTTNG_DOMAIN_UST_EXEC_NAME:
2409 case LTTNG_DOMAIN_UST_PID:
2410 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2411 default:
2412 ret = LTTCOMM_NOT_IMPLEMENTED;
2413 goto error;
2414 }
2415
2416 ret = LTTCOMM_OK;
2417
2418 error:
2419 return ret;
2420 }
2421
2422 /*
2423 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2424 */
2425 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2426 char *channel_name, int event_type)
2427 {
2428 int ret;
2429 struct ltt_kernel_channel *kchan;
2430
2431 switch (domain) {
2432 case LTTNG_DOMAIN_KERNEL:
2433 kchan = trace_kernel_get_channel_by_name(channel_name,
2434 session->kernel_session);
2435 if (kchan == NULL) {
2436 /* This call will notify the kernel thread */
2437 ret = channel_kernel_create(session->kernel_session, NULL,
2438 kernel_poll_pipe[1]);
2439 if (ret != LTTCOMM_OK) {
2440 goto error;
2441 }
2442 }
2443
2444 /* Get the newly created kernel channel pointer */
2445 kchan = trace_kernel_get_channel_by_name(channel_name,
2446 session->kernel_session);
2447 if (kchan == NULL) {
2448 /* This sould not happen... */
2449 ret = LTTCOMM_FATAL;
2450 goto error;
2451 }
2452
2453 switch (event_type) {
2454 case LTTNG_KERNEL_SYSCALL:
2455 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2456 kchan, kernel_tracer_fd);
2457 break;
2458 case LTTNG_KERNEL_TRACEPOINT:
2459 /*
2460 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2461 * events already registered to the channel.
2462 */
2463 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2464 kchan, kernel_tracer_fd);
2465 break;
2466 case LTTNG_KERNEL_ALL:
2467 /* Enable syscalls and tracepoints */
2468 ret = event_kernel_enable_all(session->kernel_session,
2469 kchan, kernel_tracer_fd);
2470 break;
2471 default:
2472 ret = LTTCOMM_KERN_ENABLE_FAIL;
2473 goto error;
2474 }
2475 if (ret != LTTCOMM_OK) {
2476 goto error;
2477 }
2478
2479 kernel_wait_quiescent(kernel_tracer_fd);
2480 break;
2481 default:
2482 /* TODO: Userspace tracing */
2483 ret = LTTCOMM_NOT_IMPLEMENTED;
2484 goto error;
2485 }
2486
2487 ret = LTTCOMM_OK;
2488
2489 error:
2490 return ret;
2491 }
2492
2493 /*
2494 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2495 */
2496 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2497 {
2498 int ret;
2499 ssize_t nb_events = 0;
2500
2501 switch (domain) {
2502 case LTTNG_DOMAIN_KERNEL:
2503 nb_events = kernel_list_events(kernel_tracer_fd, events);
2504 if (nb_events < 0) {
2505 ret = LTTCOMM_KERN_LIST_FAIL;
2506 goto error;
2507 }
2508 break;
2509 case LTTNG_DOMAIN_UST:
2510 nb_events = ust_app_list_events(events);
2511 if (nb_events < 0) {
2512 ret = LTTCOMM_UST_LIST_FAIL;
2513 goto error;
2514 }
2515 break;
2516 default:
2517 ret = LTTCOMM_NOT_IMPLEMENTED;
2518 goto error;
2519 }
2520
2521 return nb_events;
2522
2523 error:
2524 /* Return negative value to differentiate return code */
2525 return -ret;
2526 }
2527
2528 /*
2529 * Command LTTNG_START_TRACE processed by the client thread.
2530 */
2531 static int cmd_start_trace(struct ltt_session *session)
2532 {
2533 int ret;
2534 struct ltt_kernel_session *ksession;
2535 struct ltt_ust_session *usess;
2536
2537 /* Short cut */
2538 ksession = session->kernel_session;
2539 usess = session->ust_session;
2540
2541 if (session->enabled)
2542 return LTTCOMM_UST_START_FAIL;
2543 session->enabled = 1;
2544
2545 /* Kernel tracing */
2546 if (ksession != NULL) {
2547 struct ltt_kernel_channel *kchan;
2548
2549 /* Open kernel metadata */
2550 if (ksession->metadata == NULL) {
2551 ret = kernel_open_metadata(ksession, ksession->trace_path);
2552 if (ret < 0) {
2553 ret = LTTCOMM_KERN_META_FAIL;
2554 goto error;
2555 }
2556 }
2557
2558 /* Open kernel metadata stream */
2559 if (ksession->metadata_stream_fd == 0) {
2560 ret = kernel_open_metadata_stream(ksession);
2561 if (ret < 0) {
2562 ERR("Kernel create metadata stream failed");
2563 ret = LTTCOMM_KERN_STREAM_FAIL;
2564 goto error;
2565 }
2566 }
2567
2568 /* For each channel */
2569 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2570 if (kchan->stream_count == 0) {
2571 ret = kernel_open_channel_stream(kchan);
2572 if (ret < 0) {
2573 ret = LTTCOMM_KERN_STREAM_FAIL;
2574 goto error;
2575 }
2576 /* Update the stream global counter */
2577 ksession->stream_count_global += ret;
2578 }
2579 }
2580
2581 /* Setup kernel consumer socket and send fds to it */
2582 ret = init_kernel_tracing(ksession);
2583 if (ret < 0) {
2584 ret = LTTCOMM_KERN_START_FAIL;
2585 goto error;
2586 }
2587
2588 /* This start the kernel tracing */
2589 ret = kernel_start_session(ksession);
2590 if (ret < 0) {
2591 ret = LTTCOMM_KERN_START_FAIL;
2592 goto error;
2593 }
2594
2595 /* Quiescent wait after starting trace */
2596 kernel_wait_quiescent(kernel_tracer_fd);
2597 }
2598
2599 /* Flag session that trace should start automatically */
2600 if (usess) {
2601 usess->start_trace = 1;
2602
2603 ret = ust_app_start_trace_all(usess);
2604 if (ret < 0) {
2605 ret = LTTCOMM_UST_START_FAIL;
2606 goto error;
2607 }
2608 }
2609
2610 ret = LTTCOMM_OK;
2611
2612 error:
2613 return ret;
2614 }
2615
2616 /*
2617 * Command LTTNG_STOP_TRACE processed by the client thread.
2618 */
2619 static int cmd_stop_trace(struct ltt_session *session)
2620 {
2621 int ret;
2622 struct ltt_kernel_channel *kchan;
2623 struct ltt_kernel_session *ksession;
2624 struct ltt_ust_session *usess;
2625
2626 /* Short cut */
2627 ksession = session->kernel_session;
2628 usess = session->ust_session;
2629
2630 if (!session->enabled)
2631 return LTTCOMM_UST_START_FAIL;
2632 session->enabled = 0;
2633
2634 /* Kernel tracer */
2635 if (ksession != NULL) {
2636 DBG("Stop kernel tracing");
2637
2638 /* Flush all buffers before stopping */
2639 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2640 if (ret < 0) {
2641 ERR("Kernel metadata flush failed");
2642 }
2643
2644 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2645 ret = kernel_flush_buffer(kchan);
2646 if (ret < 0) {
2647 ERR("Kernel flush buffer error");
2648 }
2649 }
2650
2651 ret = kernel_stop_session(ksession);
2652 if (ret < 0) {
2653 ret = LTTCOMM_KERN_STOP_FAIL;
2654 goto error;
2655 }
2656
2657 kernel_wait_quiescent(kernel_tracer_fd);
2658 }
2659
2660 /* Flag session that trace should start automatically */
2661 if (usess) {
2662 usess->start_trace = 0;
2663
2664 ret = ust_app_stop_trace_all(usess);
2665 if (ret < 0) {
2666 ret = LTTCOMM_UST_START_FAIL;
2667 goto error;
2668 }
2669 }
2670
2671 ret = LTTCOMM_OK;
2672
2673 error:
2674 return ret;
2675 }
2676
2677 /*
2678 * Command LTTNG_CREATE_SESSION processed by the client thread.
2679 */
2680 static int cmd_create_session(char *name, char *path)
2681 {
2682 int ret;
2683
2684 ret = session_create(name, path);
2685 if (ret != LTTCOMM_OK) {
2686 goto error;
2687 }
2688
2689 ret = LTTCOMM_OK;
2690
2691 error:
2692 return ret;
2693 }
2694
2695 /*
2696 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2697 */
2698 static int cmd_destroy_session(struct ltt_session *session, char *name)
2699 {
2700 int ret;
2701
2702 /* Clean kernel session teardown */
2703 teardown_kernel_session(session);
2704 /* UST session teardown */
2705 teardown_ust_session(session);
2706
2707 /*
2708 * Must notify the kernel thread here to update it's poll setin order
2709 * to remove the channel(s)' fd just destroyed.
2710 */
2711 ret = notify_thread_pipe(kernel_poll_pipe[1]);
2712 if (ret < 0) {
2713 perror("write kernel poll pipe");
2714 }
2715
2716 ret = session_destroy(session);
2717
2718 return ret;
2719 }
2720
2721 /*
2722 * Command LTTNG_CALIBRATE processed by the client thread.
2723 */
2724 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2725 {
2726 int ret;
2727
2728 switch (domain) {
2729 case LTTNG_DOMAIN_KERNEL:
2730 {
2731 struct lttng_kernel_calibrate kcalibrate;
2732
2733 kcalibrate.type = calibrate->type;
2734 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2735 if (ret < 0) {
2736 ret = LTTCOMM_KERN_ENABLE_FAIL;
2737 goto error;
2738 }
2739 break;
2740 }
2741 default:
2742 /* TODO: Userspace tracing */
2743 ret = LTTCOMM_NOT_IMPLEMENTED;
2744 goto error;
2745 }
2746
2747 ret = LTTCOMM_OK;
2748
2749 error:
2750 return ret;
2751 }
2752
2753 /*
2754 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2755 */
2756 static int cmd_register_consumer(struct ltt_session *session, int domain,
2757 char *sock_path)
2758 {
2759 int ret, sock;
2760
2761 switch (domain) {
2762 case LTTNG_DOMAIN_KERNEL:
2763 /* Can't register a consumer if there is already one */
2764 if (session->kernel_session->consumer_fd != 0) {
2765 ret = LTTCOMM_KERN_CONSUMER_FAIL;
2766 goto error;
2767 }
2768
2769 sock = lttcomm_connect_unix_sock(sock_path);
2770 if (sock < 0) {
2771 ret = LTTCOMM_CONNECT_FAIL;
2772 goto error;
2773 }
2774
2775 session->kernel_session->consumer_fd = sock;
2776 break;
2777 default:
2778 /* TODO: Userspace tracing */
2779 ret = LTTCOMM_NOT_IMPLEMENTED;
2780 goto error;
2781 }
2782
2783 ret = LTTCOMM_OK;
2784
2785 error:
2786 return ret;
2787 }
2788
2789 /*
2790 * Command LTTNG_LIST_DOMAINS processed by the client thread.
2791 */
2792 static ssize_t cmd_list_domains(struct ltt_session *session,
2793 struct lttng_domain **domains)
2794 {
2795 int ret, index = 0;
2796 ssize_t nb_dom = 0;
2797
2798 if (session->kernel_session != NULL) {
2799 DBG3("Listing domains found kernel domain");
2800 nb_dom++;
2801 }
2802
2803 if (session->ust_session != NULL) {
2804 DBG3("Listing domains found UST global domain");
2805 nb_dom++;
2806 }
2807
2808 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
2809 if (*domains == NULL) {
2810 ret = -LTTCOMM_FATAL;
2811 goto error;
2812 }
2813
2814 if (session->kernel_session != NULL) {
2815 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
2816 index++;
2817 }
2818
2819 if (session->ust_session != NULL) {
2820 (*domains)[index].type = LTTNG_DOMAIN_UST;
2821 index++;
2822 }
2823
2824 return nb_dom;
2825
2826 error:
2827 return ret;
2828 }
2829
2830 /*
2831 * Command LTTNG_LIST_CHANNELS processed by the client thread.
2832 */
2833 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
2834 struct lttng_channel **channels)
2835 {
2836 int ret;
2837 ssize_t nb_chan = 0;
2838
2839 switch (domain) {
2840 case LTTNG_DOMAIN_KERNEL:
2841 if (session->kernel_session != NULL) {
2842 nb_chan = session->kernel_session->channel_count;
2843 }
2844 DBG3("Number of kernel channels %zd", nb_chan);
2845 break;
2846 case LTTNG_DOMAIN_UST:
2847 if (session->ust_session != NULL) {
2848 nb_chan = hashtable_get_count(
2849 session->ust_session->domain_global.channels);
2850 }
2851 DBG3("Number of UST global channels %zd", nb_chan);
2852 break;
2853 default:
2854 *channels = NULL;
2855 ret = -LTTCOMM_NOT_IMPLEMENTED;
2856 goto error;
2857 }
2858
2859 if (nb_chan > 0) {
2860 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
2861 if (*channels == NULL) {
2862 ret = -LTTCOMM_FATAL;
2863 goto error;
2864 }
2865
2866 list_lttng_channels(domain, session, *channels);
2867 } else {
2868 *channels = NULL;
2869 }
2870
2871 return nb_chan;
2872
2873 error:
2874 return ret;
2875 }
2876
2877 /*
2878 * Command LTTNG_LIST_EVENTS processed by the client thread.
2879 */
2880 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
2881 char *channel_name, struct lttng_event **events)
2882 {
2883 int ret = 0;
2884 ssize_t nb_event = 0;
2885
2886 switch (domain) {
2887 case LTTNG_DOMAIN_KERNEL:
2888 if (session->kernel_session != NULL) {
2889 nb_event = list_lttng_kernel_events(channel_name,
2890 session->kernel_session, events);
2891 }
2892 break;
2893 case LTTNG_DOMAIN_UST:
2894 {
2895 if (session->ust_session != NULL) {
2896 nb_event = list_lttng_ust_global_events(channel_name,
2897 &session->ust_session->domain_global, events);
2898 }
2899 break;
2900 }
2901 default:
2902 ret = -LTTCOMM_NOT_IMPLEMENTED;
2903 goto error;
2904 }
2905
2906 ret = nb_event;
2907
2908 error:
2909 return ret;
2910 }
2911
2912 /*
2913 * Process the command requested by the lttng client within the command
2914 * context structure. This function make sure that the return structure (llm)
2915 * is set and ready for transmission before returning.
2916 *
2917 * Return any error encountered or 0 for success.
2918 */
2919 static int process_client_msg(struct command_ctx *cmd_ctx)
2920 {
2921 int ret = LTTCOMM_OK;
2922 int need_tracing_session = 1;
2923
2924 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
2925
2926 /*
2927 * Check for command that don't needs to allocate a returned payload. We do
2928 * this here so we don't have to make the call for no payload at each
2929 * command.
2930 */
2931 switch(cmd_ctx->lsm->cmd_type) {
2932 case LTTNG_LIST_SESSIONS:
2933 case LTTNG_LIST_TRACEPOINTS:
2934 case LTTNG_LIST_DOMAINS:
2935 case LTTNG_LIST_CHANNELS:
2936 case LTTNG_LIST_EVENTS:
2937 break;
2938 default:
2939 /* Setup lttng message with no payload */
2940 ret = setup_lttng_msg(cmd_ctx, 0);
2941 if (ret < 0) {
2942 /* This label does not try to unlock the session */
2943 goto init_setup_error;
2944 }
2945 }
2946
2947 /* Commands that DO NOT need a session. */
2948 switch (cmd_ctx->lsm->cmd_type) {
2949 case LTTNG_CALIBRATE:
2950 case LTTNG_CREATE_SESSION:
2951 case LTTNG_LIST_SESSIONS:
2952 case LTTNG_LIST_TRACEPOINTS:
2953 need_tracing_session = 0;
2954 break;
2955 default:
2956 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
2957 session_lock_list();
2958 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
2959 session_unlock_list();
2960 if (cmd_ctx->session == NULL) {
2961 if (cmd_ctx->lsm->session.name != NULL) {
2962 ret = LTTCOMM_SESS_NOT_FOUND;
2963 } else {
2964 /* If no session name specified */
2965 ret = LTTCOMM_SELECT_SESS;
2966 }
2967 goto error;
2968 } else {
2969 /* Acquire lock for the session */
2970 session_lock(cmd_ctx->session);
2971 }
2972 break;
2973 }
2974
2975 /*
2976 * Check domain type for specific "pre-action".
2977 */
2978 switch (cmd_ctx->lsm->domain.type) {
2979 case LTTNG_DOMAIN_KERNEL:
2980 /* Kernel tracer check */
2981 if (kernel_tracer_fd == 0) {
2982 /* Basically, load kernel tracer modules */
2983 init_kernel_tracer();
2984 if (kernel_tracer_fd == 0) {
2985 ret = LTTCOMM_KERN_NA;
2986 goto error;
2987 }
2988 }
2989
2990 /* Need a session for kernel command */
2991 if (need_tracing_session) {
2992 if (cmd_ctx->session->kernel_session == NULL) {
2993 ret = create_kernel_session(cmd_ctx->session);
2994 if (ret < 0) {
2995 ret = LTTCOMM_KERN_SESS_FAIL;
2996 goto error;
2997 }
2998 }
2999
3000 /* Start the kernel consumer daemon */
3001 pthread_mutex_lock(&kconsumer_data.pid_mutex);
3002 if (kconsumer_data.pid == 0 &&
3003 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3004 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3005 ret = start_consumerd(&kconsumer_data);
3006 if (ret < 0) {
3007 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3008 goto error;
3009 }
3010 }
3011 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3012 }
3013 break;
3014 case LTTNG_DOMAIN_UST:
3015 {
3016 if (need_tracing_session) {
3017 if (cmd_ctx->session->ust_session == NULL) {
3018 ret = create_ust_session(cmd_ctx->session,
3019 &cmd_ctx->lsm->domain);
3020 if (ret != LTTCOMM_OK) {
3021 goto error;
3022 }
3023 }
3024 /* Start the kernel consumer daemon */
3025 pthread_mutex_lock(&ustconsumer_data.pid_mutex);
3026 if (ustconsumer_data.pid == 0 &&
3027 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3028 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3029 ret = start_consumerd(&ustconsumer_data);
3030 if (ret < 0) {
3031 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3032 goto error;
3033 }
3034
3035 ust_consumer_fd = ustconsumer_data.cmd_sock;
3036 }
3037 pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
3038 }
3039 break;
3040 }
3041 default:
3042 break;
3043 }
3044
3045 /* Process by command type */
3046 switch (cmd_ctx->lsm->cmd_type) {
3047 case LTTNG_ADD_CONTEXT:
3048 {
3049 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3050 cmd_ctx->lsm->u.context.channel_name,
3051 cmd_ctx->lsm->u.context.event_name,
3052 &cmd_ctx->lsm->u.context.ctx);
3053 break;
3054 }
3055 case LTTNG_DISABLE_CHANNEL:
3056 {
3057 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3058 cmd_ctx->lsm->u.disable.channel_name);
3059 break;
3060 }
3061 case LTTNG_DISABLE_EVENT:
3062 {
3063 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3064 cmd_ctx->lsm->u.disable.channel_name,
3065 cmd_ctx->lsm->u.disable.name);
3066 ret = LTTCOMM_OK;
3067 break;
3068 }
3069 case LTTNG_DISABLE_ALL_EVENT:
3070 {
3071 DBG("Disabling all events");
3072
3073 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3074 cmd_ctx->lsm->u.disable.channel_name);
3075 break;
3076 }
3077 case LTTNG_ENABLE_CHANNEL:
3078 {
3079 ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
3080 &cmd_ctx->lsm->u.channel.chan);
3081 break;
3082 }
3083 case LTTNG_ENABLE_EVENT:
3084 {
3085 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3086 cmd_ctx->lsm->u.enable.channel_name,
3087 &cmd_ctx->lsm->u.enable.event);
3088 break;
3089 }
3090 case LTTNG_ENABLE_ALL_EVENT:
3091 {
3092 DBG("Enabling all events");
3093
3094 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3095 cmd_ctx->lsm->u.enable.channel_name,
3096 cmd_ctx->lsm->u.enable.event.type);
3097 break;
3098 }
3099 case LTTNG_LIST_TRACEPOINTS:
3100 {
3101 struct lttng_event *events;
3102 ssize_t nb_events;
3103
3104 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
3105 if (nb_events < 0) {
3106 ret = -nb_events;
3107 goto error;
3108 }
3109
3110 /*
3111 * Setup lttng message with payload size set to the event list size in
3112 * bytes and then copy list into the llm payload.
3113 */
3114 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
3115 if (ret < 0) {
3116 free(events);
3117 goto setup_error;
3118 }
3119
3120 /* Copy event list into message payload */
3121 memcpy(cmd_ctx->llm->payload, events,
3122 sizeof(struct lttng_event) * nb_events);
3123
3124 free(events);
3125
3126 ret = LTTCOMM_OK;
3127 break;
3128 }
3129 case LTTNG_START_TRACE:
3130 {
3131 ret = cmd_start_trace(cmd_ctx->session);
3132 break;
3133 }
3134 case LTTNG_STOP_TRACE:
3135 {
3136 ret = cmd_stop_trace(cmd_ctx->session);
3137 break;
3138 }
3139 case LTTNG_CREATE_SESSION:
3140 {
3141 ret = cmd_create_session(cmd_ctx->lsm->session.name,
3142 cmd_ctx->lsm->session.path);
3143 break;
3144 }
3145 case LTTNG_DESTROY_SESSION:
3146 {
3147 ret = cmd_destroy_session(cmd_ctx->session,
3148 cmd_ctx->lsm->session.name);
3149 break;
3150 }
3151 case LTTNG_LIST_DOMAINS:
3152 {
3153 ssize_t nb_dom;
3154 struct lttng_domain *domains;
3155
3156 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
3157 if (nb_dom < 0) {
3158 ret = -nb_dom;
3159 goto error;
3160 }
3161
3162 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
3163 if (ret < 0) {
3164 goto setup_error;
3165 }
3166
3167 /* Copy event list into message payload */
3168 memcpy(cmd_ctx->llm->payload, domains,
3169 nb_dom * sizeof(struct lttng_domain));
3170
3171 free(domains);
3172
3173 ret = LTTCOMM_OK;
3174 break;
3175 }
3176 case LTTNG_LIST_CHANNELS:
3177 {
3178 size_t nb_chan;
3179 struct lttng_channel *channels;
3180
3181 nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
3182 cmd_ctx->session, &channels);
3183 if (nb_chan < 0) {
3184 ret = -nb_chan;
3185 goto error;
3186 }
3187
3188 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3189 if (ret < 0) {
3190 goto setup_error;
3191 }
3192
3193 /* Copy event list into message payload */
3194 memcpy(cmd_ctx->llm->payload, channels,
3195 nb_chan * sizeof(struct lttng_channel));
3196
3197 free(channels);
3198
3199 ret = LTTCOMM_OK;
3200 break;
3201 }
3202 case LTTNG_LIST_EVENTS:
3203 {
3204 ssize_t nb_event;
3205 struct lttng_event *events = NULL;
3206
3207 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
3208 cmd_ctx->lsm->u.list.channel_name, &events);
3209 if (nb_event < 0) {
3210 ret = -nb_event;
3211 goto error;
3212 }
3213
3214 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3215 if (ret < 0) {
3216 goto setup_error;
3217 }
3218
3219 /* Copy event list into message payload */
3220 memcpy(cmd_ctx->llm->payload, events,
3221 nb_event * sizeof(struct lttng_event));
3222
3223 free(events);
3224
3225 ret = LTTCOMM_OK;
3226 break;
3227 }
3228 case LTTNG_LIST_SESSIONS:
3229 {
3230 session_lock_list();
3231
3232 if (session_list_ptr->count == 0) {
3233 ret = LTTCOMM_NO_SESSION;
3234 session_unlock_list();
3235 goto error;
3236 }
3237
3238 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
3239 session_list_ptr->count);
3240 if (ret < 0) {
3241 session_unlock_list();
3242 goto setup_error;
3243 }
3244
3245 /* Filled the session array */
3246 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
3247
3248 session_unlock_list();
3249
3250 ret = LTTCOMM_OK;
3251 break;
3252 }
3253 case LTTNG_CALIBRATE:
3254 {
3255 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3256 &cmd_ctx->lsm->u.calibrate);
3257 break;
3258 }
3259 case LTTNG_REGISTER_CONSUMER:
3260 {
3261 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3262 cmd_ctx->lsm->u.reg.path);
3263 break;
3264 }
3265 default:
3266 ret = LTTCOMM_UND;
3267 break;
3268 }
3269
3270 error:
3271 if (cmd_ctx->llm == NULL) {
3272 DBG("Missing llm structure. Allocating one.");
3273 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3274 goto setup_error;
3275 }
3276 }
3277 /* Set return code */
3278 cmd_ctx->llm->ret_code = ret;
3279 setup_error:
3280 if (cmd_ctx->session) {
3281 session_unlock(cmd_ctx->session);
3282 }
3283 init_setup_error:
3284 return ret;
3285 }
3286
3287 /*
3288 * This thread manage all clients request using the unix client socket for
3289 * communication.
3290 */
3291 static void *thread_manage_clients(void *data)
3292 {
3293 int sock = 0, ret, i, pollfd;
3294 uint32_t revents, nb_fd;
3295 struct command_ctx *cmd_ctx = NULL;
3296 struct lttng_poll_event events;
3297
3298 DBG("[thread] Manage client started");
3299
3300 rcu_register_thread();
3301
3302 ret = lttcomm_listen_unix_sock(client_sock);
3303 if (ret < 0) {
3304 goto error;
3305 }
3306
3307 /*
3308 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
3309 * more will be added to this poll set.
3310 */
3311 ret = create_thread_poll_set(&events, 2);
3312 if (ret < 0) {
3313 goto error;
3314 }
3315
3316 /* Add the application registration socket */
3317 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
3318 if (ret < 0) {
3319 goto error;
3320 }
3321
3322 /*
3323 * Notify parent pid that we are ready to accept command for client side.
3324 */
3325 if (opt_sig_parent) {
3326 kill(ppid, SIGCHLD);
3327 }
3328
3329 while (1) {
3330 DBG("Accepting client command ...");
3331
3332 nb_fd = LTTNG_POLL_GETNB(&events);
3333
3334 /* Inifinite blocking call, waiting for transmission */
3335 ret = lttng_poll_wait(&events, -1);
3336 if (ret < 0) {
3337 goto error;
3338 }
3339
3340 for (i = 0; i < nb_fd; i++) {
3341 /* Fetch once the poll data */
3342 revents = LTTNG_POLL_GETEV(&events, i);
3343 pollfd = LTTNG_POLL_GETFD(&events, i);
3344
3345 /* Thread quit pipe has been closed. Killing thread. */
3346 ret = check_thread_quit_pipe(pollfd, revents);
3347 if (ret) {
3348 goto error;
3349 }
3350
3351 /* Event on the registration socket */
3352 if (pollfd == client_sock) {
3353 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3354 ERR("Client socket poll error");
3355 goto error;
3356 }
3357 }
3358 }
3359
3360 DBG("Wait for client response");
3361
3362 sock = lttcomm_accept_unix_sock(client_sock);
3363 if (sock < 0) {
3364 goto error;
3365 }
3366
3367 /* Allocate context command to process the client request */
3368 cmd_ctx = zmalloc(sizeof(struct command_ctx));
3369 if (cmd_ctx == NULL) {
3370 perror("zmalloc cmd_ctx");
3371 goto error;
3372 }
3373
3374 /* Allocate data buffer for reception */
3375 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
3376 if (cmd_ctx->lsm == NULL) {
3377 perror("zmalloc cmd_ctx->lsm");
3378 goto error;
3379 }
3380
3381 cmd_ctx->llm = NULL;
3382 cmd_ctx->session = NULL;
3383
3384 /*
3385 * Data is received from the lttng client. The struct
3386 * lttcomm_session_msg (lsm) contains the command and data request of
3387 * the client.
3388 */
3389 DBG("Receiving data from client ...");
3390 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm,
3391 sizeof(struct lttcomm_session_msg));
3392 if (ret <= 0) {
3393 DBG("Nothing recv() from client... continuing");
3394 close(sock);
3395 free(cmd_ctx);
3396 continue;
3397 }
3398
3399 // TODO: Validate cmd_ctx including sanity check for
3400 // security purpose.
3401
3402 rcu_thread_online();
3403 /*
3404 * This function dispatch the work to the kernel or userspace tracer
3405 * libs and fill the lttcomm_lttng_msg data structure of all the needed
3406 * informations for the client. The command context struct contains
3407 * everything this function may needs.
3408 */
3409 ret = process_client_msg(cmd_ctx);
3410 rcu_thread_offline();
3411 if (ret < 0) {
3412 /*
3413 * TODO: Inform client somehow of the fatal error. At
3414 * this point, ret < 0 means that a zmalloc failed
3415 * (ENOMEM). Error detected but still accept command.
3416 */
3417 clean_command_ctx(&cmd_ctx);
3418 continue;
3419 }
3420
3421 DBG("Sending response (size: %d, retcode: %s)",
3422 cmd_ctx->lttng_msg_size,
3423 lttng_strerror(-cmd_ctx->llm->ret_code));
3424 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
3425 if (ret < 0) {
3426 ERR("Failed to send data back to client");
3427 }
3428
3429 clean_command_ctx(&cmd_ctx);
3430
3431 /* End of transmission */
3432 close(sock);
3433 }
3434
3435 error:
3436 DBG("Client thread dying");
3437 unlink(client_unix_sock_path);
3438 close(client_sock);
3439 close(sock);
3440
3441 lttng_poll_clean(&events);
3442 clean_command_ctx(&cmd_ctx);
3443
3444 rcu_unregister_thread();
3445 return NULL;
3446 }
3447
3448
3449 /*
3450 * usage function on stderr
3451 */
3452 static void usage(void)
3453 {
3454 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
3455 fprintf(stderr, " -h, --help Display this usage.\n");
3456 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
3457 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
3458 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
3459 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
3460 fprintf(stderr, " --ustconsumerd-err-sock PATH Specify path for the UST consumer error socket\n");
3461 fprintf(stderr, " --ustconsumerd-cmd-sock PATH Specify path for the UST consumer command socket\n");
3462 fprintf(stderr, " --ustconsumerd-compat32 PATH Specify path for the 32-bit UST consumer daemon binary\n");
3463 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
3464 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
3465 fprintf(stderr, " -V, --version Show version number.\n");
3466 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
3467 fprintf(stderr, " -q, --quiet No output at all.\n");
3468 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
3469 fprintf(stderr, " --verbose-consumer Verbose mode for consumer. Activate DBG() macro.\n");
3470 }
3471
3472 /*
3473 * daemon argument parsing
3474 */
3475 static int parse_args(int argc, char **argv)
3476 {
3477 int c;
3478
3479 static struct option long_options[] = {
3480 { "client-sock", 1, 0, 'c' },
3481 { "apps-sock", 1, 0, 'a' },
3482 { "kconsumerd-cmd-sock", 1, 0, 'C' },
3483 { "kconsumerd-err-sock", 1, 0, 'E' },
3484 { "ustconsumerd-cmd-sock", 1, 0, 'D' },
3485 { "ustconsumerd-err-sock", 1, 0, 'F' },
3486 { "ustconsumerd-compat32", 1, 0, 'u' },
3487 { "daemonize", 0, 0, 'd' },
3488 { "sig-parent", 0, 0, 'S' },
3489 { "help", 0, 0, 'h' },
3490 { "group", 1, 0, 'g' },
3491 { "version", 0, 0, 'V' },
3492 { "quiet", 0, 0, 'q' },
3493 { "verbose", 0, 0, 'v' },
3494 { "verbose-consumer", 0, 0, 'Z' },
3495 { NULL, 0, 0, 0 }
3496 };
3497
3498 while (1) {
3499 int option_index = 0;
3500 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:C:E:D:F:Z:u",
3501 long_options, &option_index);
3502 if (c == -1) {
3503 break;
3504 }
3505
3506 switch (c) {
3507 case 0:
3508 fprintf(stderr, "option %s", long_options[option_index].name);
3509 if (optarg) {
3510 fprintf(stderr, " with arg %s\n", optarg);
3511 }
3512 break;
3513 case 'c':
3514 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
3515 break;
3516 case 'a':
3517 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
3518 break;
3519 case 'd':
3520 opt_daemon = 1;
3521 break;
3522 case 'g':
3523 opt_tracing_group = optarg;
3524 break;
3525 case 'h':
3526 usage();
3527 exit(EXIT_FAILURE);
3528 case 'V':
3529 fprintf(stdout, "%s\n", VERSION);
3530 exit(EXIT_SUCCESS);
3531 case 'S':
3532 opt_sig_parent = 1;
3533 break;
3534 case 'E':
3535 snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3536 break;
3537 case 'C':
3538 snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3539 break;
3540 case 'F':
3541 snprintf(ustconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
3542 break;
3543 case 'D':
3544 snprintf(ustconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
3545 break;
3546 case 'q':
3547 opt_quiet = 1;
3548 break;
3549 case 'v':
3550 /* Verbose level can increase using multiple -v */
3551 opt_verbose += 1;
3552 break;
3553 case 'Z':
3554 opt_verbose_consumer += 1;
3555 break;
3556 case 'u':
3557 compat32_consumer_bindir = optarg;
3558 break;
3559 default:
3560 /* Unknown option or other error.
3561 * Error is printed by getopt, just return */
3562 return -1;
3563 }
3564 }
3565
3566 return 0;
3567 }
3568
3569 /*
3570 * Creates the two needed socket by the daemon.
3571 * apps_sock - The communication socket for all UST apps.
3572 * client_sock - The communication of the cli tool (lttng).
3573 */
3574 static int init_daemon_socket(void)
3575 {
3576 int ret = 0;
3577 mode_t old_umask;
3578
3579 old_umask = umask(0);
3580
3581 /* Create client tool unix socket */
3582 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
3583 if (client_sock < 0) {
3584 ERR("Create unix sock failed: %s", client_unix_sock_path);
3585 ret = -1;
3586 goto end;
3587 }
3588
3589 /* File permission MUST be 660 */
3590 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3591 if (ret < 0) {
3592 ERR("Set file permissions failed: %s", client_unix_sock_path);
3593 perror("chmod");
3594 goto end;
3595 }
3596
3597 /* Create the application unix socket */
3598 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
3599 if (apps_sock < 0) {
3600 ERR("Create unix sock failed: %s", apps_unix_sock_path);
3601 ret = -1;
3602 goto end;
3603 }
3604
3605 /* File permission MUST be 666 */
3606 ret = chmod(apps_unix_sock_path,
3607 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
3608 if (ret < 0) {
3609 ERR("Set file permissions failed: %s", apps_unix_sock_path);
3610 perror("chmod");
3611 goto end;
3612 }
3613
3614 end:
3615 umask(old_umask);
3616 return ret;
3617 }
3618
3619 /*
3620 * Check if the global socket is available, and if a daemon is answering at the
3621 * other side. If yes, error is returned.
3622 */
3623 static int check_existing_daemon(void)
3624 {
3625 if (access(client_unix_sock_path, F_OK) < 0 &&
3626 access(apps_unix_sock_path, F_OK) < 0) {
3627 return 0;
3628 }
3629
3630 /* Is there anybody out there ? */
3631 if (lttng_session_daemon_alive()) {
3632 return -EEXIST;
3633 } else {
3634 return 0;
3635 }
3636 }
3637
3638 /*
3639 * Set the tracing group gid onto the client socket.
3640 *
3641 * Race window between mkdir and chown is OK because we are going from more
3642 * permissive (root.root) to les permissive (root.tracing).
3643 */
3644 static int set_permissions(void)
3645 {
3646 int ret;
3647 gid_t gid;
3648
3649 gid = allowed_group();
3650 if (gid < 0) {
3651 if (is_root) {
3652 WARN("No tracing group detected");
3653 ret = 0;
3654 } else {
3655 ERR("Missing tracing group. Aborting execution.");
3656 ret = -1;
3657 }
3658 goto end;
3659 }
3660
3661 /* Set lttng run dir */
3662 ret = chown(LTTNG_RUNDIR, 0, gid);
3663 if (ret < 0) {
3664 ERR("Unable to set group on " LTTNG_RUNDIR);
3665 perror("chown");
3666 }
3667
3668 /* lttng client socket path */
3669 ret = chown(client_unix_sock_path, 0, gid);
3670 if (ret < 0) {
3671 ERR("Unable to set group on %s", client_unix_sock_path);
3672 perror("chown");
3673 }
3674
3675 /* kconsumer error socket path */
3676 ret = chown(kconsumer_data.err_unix_sock_path, 0, gid);
3677 if (ret < 0) {
3678 ERR("Unable to set group on %s", kconsumer_data.err_unix_sock_path);
3679 perror("chown");
3680 }
3681
3682 /* ustconsumer error socket path */
3683 ret = chown(ustconsumer_data.err_unix_sock_path, 0, gid);
3684 if (ret < 0) {
3685 ERR("Unable to set group on %s", ustconsumer_data.err_unix_sock_path);
3686 perror("chown");
3687 }
3688
3689 DBG("All permissions are set");
3690
3691 end:
3692 return ret;
3693 }
3694
3695 /*
3696 * Create the pipe used to wake up the kernel thread.
3697 */
3698 static int create_kernel_poll_pipe(void)
3699 {
3700 return pipe2(kernel_poll_pipe, O_CLOEXEC);
3701 }
3702
3703 /*
3704 * Create the application command pipe to wake thread_manage_apps.
3705 */
3706 static int create_apps_cmd_pipe(void)
3707 {
3708 return pipe2(apps_cmd_pipe, O_CLOEXEC);
3709 }
3710
3711 /*
3712 * Create the lttng run directory needed for all global sockets and pipe.
3713 */
3714 static int create_lttng_rundir(void)
3715 {
3716 int ret;
3717
3718 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
3719 if (ret < 0) {
3720 if (errno != EEXIST) {
3721 ERR("Unable to create " LTTNG_RUNDIR);
3722 goto error;
3723 } else {
3724 ret = 0;
3725 }
3726 }
3727
3728 error:
3729 return ret;
3730 }
3731
3732 /*
3733 * Setup sockets and directory needed by the kconsumerd communication with the
3734 * session daemon.
3735 */
3736 static int set_consumer_sockets(struct consumer_data *consumer_data)
3737 {
3738 int ret;
3739 const char *path = consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3740 KCONSUMERD_PATH : USTCONSUMERD_PATH;
3741
3742 if (strlen(consumer_data->err_unix_sock_path) == 0) {
3743 snprintf(consumer_data->err_unix_sock_path, PATH_MAX,
3744 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3745 KCONSUMERD_ERR_SOCK_PATH :
3746 USTCONSUMERD_ERR_SOCK_PATH);
3747 }
3748
3749 if (strlen(consumer_data->cmd_unix_sock_path) == 0) {
3750 snprintf(consumer_data->cmd_unix_sock_path, PATH_MAX,
3751 consumer_data->type == LTTNG_CONSUMER_KERNEL ?
3752 KCONSUMERD_CMD_SOCK_PATH :
3753 USTCONSUMERD_CMD_SOCK_PATH);
3754 }
3755
3756 ret = mkdir(path, S_IRWXU | S_IRWXG);
3757 if (ret < 0) {
3758 if (errno != EEXIST) {
3759 ERR("Failed to create %s", path);
3760 goto error;
3761 }
3762 ret = 0;
3763 }
3764
3765 /* Create the kconsumerd error unix socket */
3766 consumer_data->err_sock =
3767 lttcomm_create_unix_sock(consumer_data->err_unix_sock_path);
3768 if (consumer_data->err_sock < 0) {
3769 ERR("Create unix sock failed: %s", consumer_data->err_unix_sock_path);
3770 ret = -1;
3771 goto error;
3772 }
3773
3774 /* File permission MUST be 660 */
3775 ret = chmod(consumer_data->err_unix_sock_path,
3776 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3777 if (ret < 0) {
3778 ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
3779 perror("chmod");
3780 goto error;
3781 }
3782
3783 error:
3784 return ret;
3785 }
3786
3787 /*
3788 * Signal handler for the daemon
3789 *
3790 * Simply stop all worker threads, leaving main() return gracefully after
3791 * joining all threads and calling cleanup().
3792 */
3793 static void sighandler(int sig)
3794 {
3795 switch (sig) {
3796 case SIGPIPE:
3797 DBG("SIGPIPE catched");
3798 return;
3799 case SIGINT:
3800 DBG("SIGINT catched");
3801 stop_threads();
3802 break;
3803 case SIGTERM:
3804 DBG("SIGTERM catched");
3805 stop_threads();
3806 break;
3807 default:
3808 break;
3809 }
3810 }
3811
3812 /*
3813 * Setup signal handler for :
3814 * SIGINT, SIGTERM, SIGPIPE
3815 */
3816 static int set_signal_handler(void)
3817 {
3818 int ret = 0;
3819 struct sigaction sa;
3820 sigset_t sigset;
3821
3822 if ((ret = sigemptyset(&sigset)) < 0) {
3823 perror("sigemptyset");
3824 return ret;
3825 }
3826
3827 sa.sa_handler = sighandler;
3828 sa.sa_mask = sigset;
3829 sa.sa_flags = 0;
3830 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
3831 perror("sigaction");
3832 return ret;
3833 }
3834
3835 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
3836 perror("sigaction");
3837 return ret;
3838 }
3839
3840 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
3841 perror("sigaction");
3842 return ret;
3843 }
3844
3845 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
3846
3847 return ret;
3848 }
3849
3850 /*
3851 * Set open files limit to unlimited. This daemon can open a large number of
3852 * file descriptors in order to consumer multiple kernel traces.
3853 */
3854 static void set_ulimit(void)
3855 {
3856 int ret;
3857 struct rlimit lim;
3858
3859 /* The kernel does not allowed an infinite limit for open files */
3860 lim.rlim_cur = 65535;
3861 lim.rlim_max = 65535;
3862
3863 ret = setrlimit(RLIMIT_NOFILE, &lim);
3864 if (ret < 0) {
3865 perror("failed to set open files limit");
3866 }
3867 }
3868
3869 /*
3870 * main
3871 */
3872 int main(int argc, char **argv)
3873 {
3874 int ret = 0;
3875 void *status;
3876 const char *home_path;
3877
3878 rcu_register_thread();
3879
3880 /* Create thread quit pipe */
3881 if ((ret = init_thread_quit_pipe()) < 0) {
3882 goto error;
3883 }
3884
3885 setup_compat32_consumer();
3886
3887 /* Parse arguments */
3888 progname = argv[0];
3889 if ((ret = parse_args(argc, argv) < 0)) {
3890 goto error;
3891 }
3892
3893 /* Daemonize */
3894 if (opt_daemon) {
3895 ret = daemon(0, 0);
3896 if (ret < 0) {
3897 perror("daemon");
3898 goto error;
3899 }
3900 }
3901
3902 /* Check if daemon is UID = 0 */
3903 is_root = !getuid();
3904
3905 if (is_root) {
3906 ret = create_lttng_rundir();
3907 if (ret < 0) {
3908 goto error;
3909 }
3910
3911 if (strlen(apps_unix_sock_path) == 0) {
3912 snprintf(apps_unix_sock_path, PATH_MAX,
3913 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
3914 }
3915
3916 if (strlen(client_unix_sock_path) == 0) {
3917 snprintf(client_unix_sock_path, PATH_MAX,
3918 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
3919 }
3920
3921 /* Set global SHM for ust */
3922 if (strlen(wait_shm_path) == 0) {
3923 snprintf(wait_shm_path, PATH_MAX,
3924 DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
3925 }
3926 } else {
3927 home_path = get_home_dir();
3928 if (home_path == NULL) {
3929 /* TODO: Add --socket PATH option */
3930 ERR("Can't get HOME directory for sockets creation.");
3931 ret = -EPERM;
3932 goto error;
3933 }
3934
3935 if (strlen(apps_unix_sock_path) == 0) {
3936 snprintf(apps_unix_sock_path, PATH_MAX,
3937 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
3938 }
3939
3940 /* Set the cli tool unix socket path */
3941 if (strlen(client_unix_sock_path) == 0) {
3942 snprintf(client_unix_sock_path, PATH_MAX,
3943 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
3944 }
3945
3946 /* Set global SHM for ust */
3947 if (strlen(wait_shm_path) == 0) {
3948 snprintf(wait_shm_path, PATH_MAX,
3949 DEFAULT_HOME_APPS_WAIT_SHM_PATH, geteuid());
3950 }
3951 }
3952
3953 DBG("Client socket path %s", client_unix_sock_path);
3954 DBG("Application socket path %s", apps_unix_sock_path);
3955
3956 /*
3957 * See if daemon already exist.
3958 */
3959 if ((ret = check_existing_daemon()) < 0) {
3960 ERR("Already running daemon.\n");
3961 /*
3962 * We do not goto exit because we must not cleanup()
3963 * because a daemon is already running.
3964 */
3965 goto error;
3966 }
3967
3968 /* After this point, we can safely call cleanup() with "goto exit" */
3969
3970 /*
3971 * These actions must be executed as root. We do that *after* setting up
3972 * the sockets path because we MUST make the check for another daemon using
3973 * those paths *before* trying to set the kernel consumer sockets and init
3974 * kernel tracer.
3975 */
3976 if (is_root) {
3977 ret = set_consumer_sockets(&kconsumer_data);
3978 if (ret < 0) {
3979 goto exit;
3980 }
3981
3982 ret = set_consumer_sockets(&ustconsumer_data);
3983 if (ret < 0) {
3984 goto exit;
3985 }
3986 /* Setup kernel tracer */
3987 init_kernel_tracer();
3988
3989 /* Set ulimit for open files */
3990 set_ulimit();
3991 }
3992
3993 if ((ret = set_signal_handler()) < 0) {
3994 goto exit;
3995 }
3996
3997 /* Setup the needed unix socket */
3998 if ((ret = init_daemon_socket()) < 0) {
3999 goto exit;
4000 }
4001
4002 /* Set credentials to socket */
4003 if (is_root && ((ret = set_permissions()) < 0)) {
4004 goto exit;
4005 }
4006
4007 /* Get parent pid if -S, --sig-parent is specified. */
4008 if (opt_sig_parent) {
4009 ppid = getppid();
4010 }
4011
4012 /* Setup the kernel pipe for waking up the kernel thread */
4013 if ((ret = create_kernel_poll_pipe()) < 0) {
4014 goto exit;
4015 }
4016
4017 /* Setup the thread apps communication pipe. */
4018 if ((ret = create_apps_cmd_pipe()) < 0) {
4019 goto exit;
4020 }
4021
4022 /* Init UST command queue. */
4023 cds_wfq_init(&ust_cmd_queue.queue);
4024
4025 /* Init UST app hash table */
4026 ust_app_ht_alloc();
4027
4028 /*
4029 * Get session list pointer. This pointer MUST NOT be free(). This list is
4030 * statically declared in session.c
4031 */
4032 session_list_ptr = session_get_list();
4033
4034 /* Set up max poll set size */
4035 lttng_poll_set_max_size();
4036
4037 /* Create thread to manage the client socket */
4038 ret = pthread_create(&client_thread, NULL,
4039 thread_manage_clients, (void *) NULL);
4040 if (ret != 0) {
4041 perror("pthread_create clients");
4042 goto exit_client;
4043 }
4044
4045 /* Create thread to dispatch registration */
4046 ret = pthread_create(&dispatch_thread, NULL,
4047 thread_dispatch_ust_registration, (void *) NULL);
4048 if (ret != 0) {
4049 perror("pthread_create dispatch");
4050 goto exit_dispatch;
4051 }
4052
4053 /* Create thread to manage application registration. */
4054 ret = pthread_create(&reg_apps_thread, NULL,
4055 thread_registration_apps, (void *) NULL);
4056 if (ret != 0) {
4057 perror("pthread_create registration");
4058 goto exit_reg_apps;
4059 }
4060
4061 /* Create thread to manage application socket */
4062 ret = pthread_create(&apps_thread, NULL,
4063 thread_manage_apps, (void *) NULL);
4064 if (ret != 0) {
4065 perror("pthread_create apps");
4066 goto exit_apps;
4067 }
4068
4069 /* Create kernel thread to manage kernel event */
4070 ret = pthread_create(&kernel_thread, NULL,
4071 thread_manage_kernel, (void *) NULL);
4072 if (ret != 0) {
4073 perror("pthread_create kernel");
4074 goto exit_kernel;
4075 }
4076
4077 ret = pthread_join(kernel_thread, &status);
4078 if (ret != 0) {
4079 perror("pthread_join");
4080 goto error; /* join error, exit without cleanup */
4081 }
4082
4083 exit_kernel:
4084 ret = pthread_join(apps_thread, &status);
4085 if (ret != 0) {
4086 perror("pthread_join");
4087 goto error; /* join error, exit without cleanup */
4088 }
4089
4090 exit_apps:
4091 ret = pthread_join(reg_apps_thread, &status);
4092 if (ret != 0) {
4093 perror("pthread_join");
4094 goto error; /* join error, exit without cleanup */
4095 }
4096
4097 exit_reg_apps:
4098 ret = pthread_join(dispatch_thread, &status);
4099 if (ret != 0) {
4100 perror("pthread_join");
4101 goto error; /* join error, exit without cleanup */
4102 }
4103
4104 exit_dispatch:
4105 ret = pthread_join(client_thread, &status);
4106 if (ret != 0) {
4107 perror("pthread_join");
4108 goto error; /* join error, exit without cleanup */
4109 }
4110
4111 ret = join_consumer_thread(&kconsumer_data);
4112 if (ret != 0) {
4113 perror("join_consumer");
4114 goto error; /* join error, exit without cleanup */
4115 }
4116
4117 exit_client:
4118 exit:
4119 /*
4120 * cleanup() is called when no other thread is running.
4121 */
4122 rcu_thread_online();
4123 cleanup();
4124 rcu_thread_offline();
4125 rcu_unregister_thread();
4126 if (!ret)
4127 exit(EXIT_SUCCESS);
4128 error:
4129 exit(EXIT_FAILURE);
4130 }
LTTng 2.0 tools and control repository
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