Fix pollfd update bug in thread_manage apps
[lttng-tools.git] / ltt-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
8 * of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20 #define _GNU_SOURCE
21 #include <fcntl.h>
22 #include <getopt.h>
23 #include <grp.h>
24 #include <limits.h>
25 #include <poll.h>
26 #include <pthread.h>
27 #include <semaphore.h>
28 #include <signal.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <sys/mman.h>
33 #include <sys/mount.h>
34 #include <sys/resource.h>
35 #include <sys/socket.h>
36 #include <sys/stat.h>
37 #include <sys/types.h>
38 #include <sys/wait.h>
39 #include <urcu/futex.h>
40 #include <unistd.h>
41
42 #include <ltt-kconsumerd.h>
43 #include <lttng-sessiond-comm.h>
44 #include <lttng/lttng-kconsumerd.h>
45 #include <lttngerr.h>
46
47 #include "context.h"
48 #include "futex.h"
49 #include "kernel-ctl.h"
50 #include "ltt-sessiond.h"
51 #include "shm.h"
52 #include "traceable-app.h"
53 #include "ust-ctl.h"
54 #include "utils.h"
55 #include "ust-ctl.h"
56
57 /* Const values */
58 const char default_home_dir[] = DEFAULT_HOME_DIR;
59 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
60 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
61 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
62
63 /* Variables */
64 int opt_verbose; /* Not static for lttngerr.h */
65 int opt_verbose_kconsumerd; /* Not static for lttngerr.h */
66 int opt_quiet; /* Not static for lttngerr.h */
67
68 const char *progname;
69 const char *opt_tracing_group;
70 static int opt_sig_parent;
71 static int opt_daemon;
72 static int is_root; /* Set to 1 if the daemon is running as root */
73 static pid_t ppid; /* Parent PID for --sig-parent option */
74 static pid_t kconsumerd_pid;
75 static struct pollfd *kernel_pollfd;
76 static int dispatch_thread_exit;
77
78 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
79 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
80 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
81 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
82 static char wait_shm_path[PATH_MAX]; /* global wait shm path for UST */
83
84 /* Sockets and FDs */
85 static int client_sock;
86 static int apps_sock;
87 static int kconsumerd_err_sock;
88 static int kconsumerd_cmd_sock;
89 static int kernel_tracer_fd;
90 static int kernel_poll_pipe[2];
91
92 /*
93 * Quit pipe for all threads. This permits a single cancellation point
94 * for all threads when receiving an event on the pipe.
95 */
96 static int thread_quit_pipe[2];
97
98 /*
99 * This pipe is used to inform the thread managing application communication
100 * that a command is queued and ready to be processed.
101 */
102 static int apps_cmd_pipe[2];
103
104 /* Pthread, Mutexes and Semaphores */
105 static pthread_t kconsumerd_thread;
106 static pthread_t apps_thread;
107 static pthread_t reg_apps_thread;
108 static pthread_t client_thread;
109 static pthread_t kernel_thread;
110 static pthread_t dispatch_thread;
111 static sem_t kconsumerd_sem;
112
113 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
114
115 /*
116 * UST registration command queue. This queue is tied with a futex and uses a N
117 * wakers / 1 waiter implemented and detailed in futex.c/.h
118 *
119 * The thread_manage_apps and thread_dispatch_ust_registration interact with
120 * this queue and the wait/wake scheme.
121 */
122 static struct ust_cmd_queue ust_cmd_queue;
123
124 /*
125 * Pointer initialized before thread creation.
126 *
127 * This points to the tracing session list containing the session count and a
128 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
129 * MUST NOT be taken if you call a public function in session.c.
130 *
131 * The lock is nested inside the structure: session_list_ptr->lock. Please use
132 * lock_session_list and unlock_session_list for lock acquisition.
133 */
134 static struct ltt_session_list *session_list_ptr;
135
136 /*
137 * Remove modules in reverse load order.
138 */
139 static int modprobe_remove_kernel_modules(void)
140 {
141 int ret = 0, i;
142 char modprobe[256];
143
144 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
145 ret = snprintf(modprobe, sizeof(modprobe),
146 "/sbin/modprobe --remove --quiet %s",
147 kernel_modules_list[i].name);
148 if (ret < 0) {
149 perror("snprintf modprobe --remove");
150 goto error;
151 }
152 modprobe[sizeof(modprobe) - 1] = '\0';
153 ret = system(modprobe);
154 if (ret == -1) {
155 ERR("Unable to launch modprobe --remove for module %s",
156 kernel_modules_list[i].name);
157 } else if (kernel_modules_list[i].required
158 && WEXITSTATUS(ret) != 0) {
159 ERR("Unable to remove module %s",
160 kernel_modules_list[i].name);
161 } else {
162 DBG("Modprobe removal successful %s",
163 kernel_modules_list[i].name);
164 }
165 }
166
167 error:
168 return ret;
169 }
170
171 /*
172 * Return group ID of the tracing group or -1 if not found.
173 */
174 static gid_t allowed_group(void)
175 {
176 struct group *grp;
177
178 if (opt_tracing_group) {
179 grp = getgrnam(opt_tracing_group);
180 } else {
181 grp = getgrnam(default_tracing_group);
182 }
183 if (!grp) {
184 return -1;
185 } else {
186 return grp->gr_gid;
187 }
188 }
189
190 /*
191 * Init quit pipe.
192 *
193 * Return -1 on error or 0 if all pipes are created.
194 */
195 static int init_thread_quit_pipe(void)
196 {
197 int ret;
198
199 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
200 if (ret < 0) {
201 perror("thread quit pipe");
202 goto error;
203 }
204
205 error:
206 return ret;
207 }
208
209 /*
210 * Complete teardown of a kernel session. This free all data structure related
211 * to a kernel session and update counter.
212 */
213 static void teardown_kernel_session(struct ltt_session *session)
214 {
215 if (session->kernel_session != NULL) {
216 DBG("Tearing down kernel session");
217
218 /*
219 * If a custom kernel consumer was registered, close the socket before
220 * tearing down the complete kernel session structure
221 */
222 if (session->kernel_session->consumer_fd != kconsumerd_cmd_sock) {
223 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
224 }
225
226 trace_kernel_destroy_session(session->kernel_session);
227 /* Extra precaution */
228 session->kernel_session = NULL;
229 }
230 }
231
232 /*
233 * Stop all threads by closing the thread quit pipe.
234 */
235 static void stop_threads(void)
236 {
237 /* Stopping all threads */
238 DBG("Terminating all threads");
239 close(thread_quit_pipe[0]);
240 close(thread_quit_pipe[1]);
241 /* Dispatch thread */
242 dispatch_thread_exit = 1;
243 futex_nto1_wake(&ust_cmd_queue.futex);
244 }
245
246 /*
247 * Cleanup the daemon
248 */
249 static void cleanup(void)
250 {
251 int ret;
252 char *cmd;
253 struct ltt_session *sess, *stmp;
254
255 DBG("Cleaning up");
256
257 /* <fun> */
258 MSG("%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
259 "Matthew, BEET driven development works!%c[%dm",
260 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
261 /* </fun> */
262
263 DBG("Removing %s directory", LTTNG_RUNDIR);
264 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
265 if (ret < 0) {
266 ERR("asprintf failed. Something is really wrong!");
267 }
268
269 /* Remove lttng run directory */
270 ret = system(cmd);
271 if (ret < 0) {
272 ERR("Unable to clean " LTTNG_RUNDIR);
273 }
274
275 DBG("Cleaning up all session");
276
277 /* Destroy session list mutex */
278 if (session_list_ptr != NULL) {
279 pthread_mutex_destroy(&session_list_ptr->lock);
280
281 /* Cleanup ALL session */
282 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
283 teardown_kernel_session(sess);
284 // TODO complete session cleanup (including UST)
285 }
286 }
287
288 DBG("Closing all UST sockets");
289 clean_traceable_apps_list();
290
291 pthread_mutex_destroy(&kconsumerd_pid_mutex);
292
293 DBG("Closing kernel fd");
294 close(kernel_tracer_fd);
295
296 if (is_root) {
297 DBG("Unloading kernel modules");
298 modprobe_remove_kernel_modules();
299 }
300 }
301
302 /*
303 * Send data on a unix socket using the liblttsessiondcomm API.
304 *
305 * Return lttcomm error code.
306 */
307 static int send_unix_sock(int sock, void *buf, size_t len)
308 {
309 /* Check valid length */
310 if (len <= 0) {
311 return -1;
312 }
313
314 return lttcomm_send_unix_sock(sock, buf, len);
315 }
316
317 /*
318 * Free memory of a command context structure.
319 */
320 static void clean_command_ctx(struct command_ctx **cmd_ctx)
321 {
322 DBG("Clean command context structure");
323 if (*cmd_ctx) {
324 if ((*cmd_ctx)->llm) {
325 free((*cmd_ctx)->llm);
326 }
327 if ((*cmd_ctx)->lsm) {
328 free((*cmd_ctx)->lsm);
329 }
330 free(*cmd_ctx);
331 *cmd_ctx = NULL;
332 }
333 }
334
335 /*
336 * Send all stream fds of kernel channel to the consumer.
337 */
338 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
339 {
340 int ret;
341 size_t nb_fd;
342 struct ltt_kernel_stream *stream;
343 struct lttcomm_kconsumerd_header lkh;
344 struct lttcomm_kconsumerd_msg lkm;
345
346 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
347
348 nb_fd = channel->stream_count;
349
350 /* Setup header */
351 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
352 lkh.cmd_type = ADD_STREAM;
353
354 DBG("Sending kconsumerd header");
355
356 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
357 if (ret < 0) {
358 perror("send kconsumerd header");
359 goto error;
360 }
361
362 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
363 if (stream->fd != 0) {
364 lkm.fd = stream->fd;
365 lkm.state = stream->state;
366 lkm.max_sb_size = channel->channel->attr.subbuf_size;
367 lkm.output = channel->channel->attr.output;
368 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
369 lkm.path_name[PATH_MAX - 1] = '\0';
370
371 DBG("Sending fd %d to kconsumerd", lkm.fd);
372
373 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
374 if (ret < 0) {
375 perror("send kconsumerd fd");
376 goto error;
377 }
378 }
379 }
380
381 DBG("Kconsumerd channel fds sent");
382
383 return 0;
384
385 error:
386 return ret;
387 }
388
389 /*
390 * Send all stream fds of the kernel session to the consumer.
391 */
392 static int send_kconsumerd_fds(struct ltt_kernel_session *session)
393 {
394 int ret;
395 struct ltt_kernel_channel *chan;
396 struct lttcomm_kconsumerd_header lkh;
397 struct lttcomm_kconsumerd_msg lkm;
398
399 /* Setup header */
400 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
401 lkh.cmd_type = ADD_STREAM;
402
403 DBG("Sending kconsumerd header for metadata");
404
405 ret = lttcomm_send_unix_sock(session->consumer_fd, &lkh, sizeof(struct lttcomm_kconsumerd_header));
406 if (ret < 0) {
407 perror("send kconsumerd header");
408 goto error;
409 }
410
411 DBG("Sending metadata stream fd");
412
413 /* Extra protection. It's NOT suppose to be set to 0 at this point */
414 if (session->consumer_fd == 0) {
415 session->consumer_fd = kconsumerd_cmd_sock;
416 }
417
418 if (session->metadata_stream_fd != 0) {
419 /* Send metadata stream fd first */
420 lkm.fd = session->metadata_stream_fd;
421 lkm.state = ACTIVE_FD;
422 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
423 lkm.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
424 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
425 lkm.path_name[PATH_MAX - 1] = '\0';
426
427 ret = lttcomm_send_fds_unix_sock(session->consumer_fd, &lkm, &lkm.fd, 1, sizeof(lkm));
428 if (ret < 0) {
429 perror("send kconsumerd fd");
430 goto error;
431 }
432 }
433
434 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
435 ret = send_kconsumerd_channel_fds(session->consumer_fd, chan);
436 if (ret < 0) {
437 goto error;
438 }
439 }
440
441 DBG("Kconsumerd fds (metadata and channel streams) sent");
442
443 return 0;
444
445 error:
446 return ret;
447 }
448
449 /*
450 * Notify UST applications using the shm mmap futex.
451 */
452 static int notify_ust_apps(int active)
453 {
454 char *wait_shm_mmap;
455
456 DBG("Notifying applications of session daemon state: %d", active);
457
458 /* See shm.c for this call implying mmap, shm and futex calls */
459 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
460 if (wait_shm_mmap == NULL) {
461 goto error;
462 }
463
464 /* Wake waiting process */
465 futex_wait_update((int32_t *) wait_shm_mmap, active);
466
467 /* Apps notified successfully */
468 return 0;
469
470 error:
471 return -1;
472 }
473
474 /*
475 * Setup the outgoing data buffer for the response (llm) by allocating the
476 * right amount of memory and copying the original information from the lsm
477 * structure.
478 *
479 * Return total size of the buffer pointed by buf.
480 */
481 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
482 {
483 int ret, buf_size;
484
485 buf_size = size;
486
487 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
488 if (cmd_ctx->llm == NULL) {
489 perror("malloc");
490 ret = -ENOMEM;
491 goto error;
492 }
493
494 /* Copy common data */
495 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
496 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
497
498 cmd_ctx->llm->data_size = size;
499 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
500
501 return buf_size;
502
503 error:
504 return ret;
505 }
506
507 /*
508 * Update the kernel pollfd set of all channel fd available over all tracing
509 * session. Add the wakeup pipe at the end of the set.
510 */
511 static int update_kernel_pollfd(void)
512 {
513 int i = 0;
514 /*
515 * The wakup pipe and the quit pipe are needed so the number of fds starts
516 * at 2 for those pipes.
517 */
518 unsigned int nb_fd = 2;
519 struct ltt_session *session;
520 struct ltt_kernel_channel *channel;
521
522 DBG("Updating kernel_pollfd");
523
524 /* Get the number of channel of all kernel session */
525 lock_session_list();
526 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
527 lock_session(session);
528 if (session->kernel_session == NULL) {
529 unlock_session(session);
530 continue;
531 }
532 nb_fd += session->kernel_session->channel_count;
533 unlock_session(session);
534 }
535
536 DBG("Resizing kernel_pollfd to size %d", nb_fd);
537
538 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
539 if (kernel_pollfd == NULL) {
540 perror("malloc kernel_pollfd");
541 goto error;
542 }
543
544 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
545 lock_session(session);
546 if (session->kernel_session == NULL) {
547 unlock_session(session);
548 continue;
549 }
550 if (i >= nb_fd) {
551 ERR("To much channel for kernel_pollfd size");
552 unlock_session(session);
553 break;
554 }
555 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
556 kernel_pollfd[i].fd = channel->fd;
557 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
558 i++;
559 }
560 unlock_session(session);
561 }
562 unlock_session_list();
563
564 /* Adding wake up pipe */
565 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
566 kernel_pollfd[nb_fd - 2].events = POLLIN;
567
568 /* Adding the quit pipe */
569 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
570
571 return nb_fd;
572
573 error:
574 unlock_session_list();
575 return -1;
576 }
577
578 /*
579 * Find the channel fd from 'fd' over all tracing session. When found, check
580 * for new channel stream and send those stream fds to the kernel consumer.
581 *
582 * Useful for CPU hotplug feature.
583 */
584 static int update_kernel_stream(int fd)
585 {
586 int ret = 0;
587 struct ltt_session *session;
588 struct ltt_kernel_channel *channel;
589
590 DBG("Updating kernel streams for channel fd %d", fd);
591
592 lock_session_list();
593 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
594 lock_session(session);
595 if (session->kernel_session == NULL) {
596 unlock_session(session);
597 continue;
598 }
599
600 /* This is not suppose to be 0 but this is an extra security check */
601 if (session->kernel_session->consumer_fd == 0) {
602 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
603 }
604
605 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
606 if (channel->fd == fd) {
607 DBG("Channel found, updating kernel streams");
608 ret = kernel_open_channel_stream(channel);
609 if (ret < 0) {
610 goto end;
611 }
612
613 /*
614 * Have we already sent fds to the consumer? If yes, it means that
615 * tracing is started so it is safe to send our updated stream fds.
616 */
617 if (session->kernel_session->kconsumer_fds_sent == 1) {
618 ret = send_kconsumerd_channel_fds(session->kernel_session->consumer_fd,
619 channel);
620 if (ret < 0) {
621 goto end;
622 }
623 }
624 goto end;
625 }
626 }
627 unlock_session(session);
628 }
629
630 end:
631 unlock_session_list();
632 if (session) {
633 unlock_session(session);
634 }
635 return ret;
636 }
637
638 /*
639 * This thread manage event coming from the kernel.
640 *
641 * Features supported in this thread:
642 * -) CPU Hotplug
643 */
644 static void *thread_manage_kernel(void *data)
645 {
646 int ret, i, nb_fd = 0;
647 char tmp;
648 int update_poll_flag = 1;
649
650 DBG("Thread manage kernel started");
651
652 while (1) {
653 if (update_poll_flag == 1) {
654 nb_fd = update_kernel_pollfd();
655 if (nb_fd < 0) {
656 goto error;
657 }
658 update_poll_flag = 0;
659 }
660
661 DBG("Polling on %d fds", nb_fd);
662
663 /* Poll infinite value of time */
664 ret = poll(kernel_pollfd, nb_fd, -1);
665 if (ret < 0) {
666 perror("poll kernel thread");
667 goto error;
668 } else if (ret == 0) {
669 /* Should not happen since timeout is infinite */
670 continue;
671 }
672
673 /* Thread quit pipe has been closed. Killing thread. */
674 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
675 goto error;
676 }
677
678 DBG("Kernel poll event triggered");
679
680 /*
681 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
682 * must be updated.
683 */
684 switch (kernel_pollfd[nb_fd - 2].revents) {
685 case POLLIN:
686 ret = read(kernel_poll_pipe[0], &tmp, 1);
687 update_poll_flag = 1;
688 continue;
689 case POLLERR:
690 goto error;
691 default:
692 break;
693 }
694
695 for (i = 0; i < nb_fd; i++) {
696 switch (kernel_pollfd[i].revents) {
697 /*
698 * New CPU detected by the kernel. Adding kernel stream to kernel
699 * session and updating the kernel consumer
700 */
701 case POLLIN | POLLRDNORM:
702 ret = update_kernel_stream(kernel_pollfd[i].fd);
703 if (ret < 0) {
704 continue;
705 }
706 break;
707 }
708 }
709 }
710
711 error:
712 DBG("Kernel thread dying");
713 if (kernel_pollfd) {
714 free(kernel_pollfd);
715 }
716
717 close(kernel_poll_pipe[0]);
718 close(kernel_poll_pipe[1]);
719 return NULL;
720 }
721
722 /*
723 * This thread manage the kconsumerd error sent back to the session daemon.
724 */
725 static void *thread_manage_kconsumerd(void *data)
726 {
727 int sock = 0, ret;
728 enum lttcomm_return_code code;
729 struct pollfd pollfd[2];
730
731 DBG("[thread] Manage kconsumerd started");
732
733 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
734 if (ret < 0) {
735 goto error;
736 }
737
738 /* First fd is always the quit pipe */
739 pollfd[0].fd = thread_quit_pipe[0];
740
741 /* Apps socket */
742 pollfd[1].fd = kconsumerd_err_sock;
743 pollfd[1].events = POLLIN;
744
745 /* Inifinite blocking call, waiting for transmission */
746 ret = poll(pollfd, 2, -1);
747 if (ret < 0) {
748 perror("poll kconsumerd thread");
749 goto error;
750 }
751
752 /* Thread quit pipe has been closed. Killing thread. */
753 if (pollfd[0].revents == POLLNVAL) {
754 goto error;
755 } else if (pollfd[1].revents == POLLERR) {
756 ERR("Kconsumerd err socket poll error");
757 goto error;
758 }
759
760 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
761 if (sock < 0) {
762 goto error;
763 }
764
765 /* Getting status code from kconsumerd */
766 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
767 if (ret <= 0) {
768 goto error;
769 }
770
771 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
772 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
773 if (kconsumerd_cmd_sock < 0) {
774 sem_post(&kconsumerd_sem);
775 perror("kconsumerd connect");
776 goto error;
777 }
778 /* Signal condition to tell that the kconsumerd is ready */
779 sem_post(&kconsumerd_sem);
780 DBG("Kconsumerd command socket ready");
781 } else {
782 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
783 lttcomm_get_readable_code(-code));
784 goto error;
785 }
786
787 /* Kconsumerd err socket */
788 pollfd[1].fd = sock;
789 pollfd[1].events = POLLIN;
790
791 /* Inifinite blocking call, waiting for transmission */
792 ret = poll(pollfd, 2, -1);
793 if (ret < 0) {
794 perror("poll kconsumerd thread");
795 goto error;
796 }
797
798 /* Thread quit pipe has been closed. Killing thread. */
799 if (pollfd[0].revents == POLLNVAL) {
800 goto error;
801 } else if (pollfd[1].revents == POLLERR) {
802 ERR("Kconsumerd err socket second poll error");
803 goto error;
804 }
805
806 /* Wait for any kconsumerd error */
807 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
808 if (ret <= 0) {
809 ERR("Kconsumerd closed the command socket");
810 goto error;
811 }
812
813 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
814
815 error:
816 DBG("Kconsumerd thread dying");
817 if (kconsumerd_err_sock) {
818 close(kconsumerd_err_sock);
819 }
820 if (kconsumerd_cmd_sock) {
821 close(kconsumerd_cmd_sock);
822 }
823 if (sock) {
824 close(sock);
825 }
826
827 unlink(kconsumerd_err_unix_sock_path);
828 unlink(kconsumerd_cmd_unix_sock_path);
829
830 kconsumerd_pid = 0;
831 return NULL;
832 }
833
834 /*
835 * Reallocate the apps command pollfd structure of nb_fd size.
836 *
837 * The first two fds must be there at all time.
838 */
839 static int update_apps_cmd_pollfd(unsigned int nb_fd, unsigned int old_nb_fd,
840 struct pollfd **pollfd)
841 {
842 int i, count;
843 struct pollfd *old_pollfd = NULL;
844
845 /* Can't accept pollfd less than 2 */
846 if (nb_fd < 2) {
847 goto end;
848 }
849
850 if (*pollfd) {
851 /* Save pointer */
852 old_pollfd = *pollfd;
853 }
854
855 *pollfd = malloc(nb_fd * sizeof(struct pollfd));
856 if (*pollfd == NULL) {
857 perror("malloc manage apps pollfd");
858 goto error;
859 }
860
861 /* First fd is always the quit pipe */
862 (*pollfd)[0].fd = thread_quit_pipe[0];
863 /* Apps command pipe */
864 (*pollfd)[1].fd = apps_cmd_pipe[0];
865 (*pollfd)[1].events = POLLIN;
866
867 /* Start count after the two pipes below */
868 count = 2;
869 for (i = 2; i < old_nb_fd; i++) {
870 /* Add to new pollfd */
871 if (old_pollfd[i].fd != -1) {
872 (*pollfd)[count].fd = old_pollfd[i].fd;
873 (*pollfd)[count].events = POLLHUP | POLLNVAL | POLLERR;
874 count++;
875 }
876
877 if (count > nb_fd) {
878 ERR("Updating poll fd wrong size");
879 goto error;
880 }
881 }
882
883 /* Destroy old pollfd */
884 free(old_pollfd);
885
886 DBG("Apps cmd pollfd realloc of size %d", nb_fd);
887
888 end:
889 return 0;
890
891 error:
892 /* Destroy old pollfd */
893 free(old_pollfd);
894 return -1;
895 }
896
897 /*
898 * This thread manage application communication.
899 */
900 static void *thread_manage_apps(void *data)
901 {
902 int i, ret, current_nb_fd;
903 unsigned int nb_fd = 2;
904 int update_poll_flag = 1;
905 struct pollfd *pollfd = NULL;
906 struct ust_command ust_cmd;
907
908 DBG("[thread] Manage application started");
909
910 ust_cmd.sock = -1;
911 current_nb_fd = nb_fd;
912
913 while (1) {
914 /* See if we have a valid socket to add to pollfd */
915 if (ust_cmd.sock != -1) {
916 nb_fd++;
917 update_poll_flag = 1;
918 }
919
920 /* The pollfd struct must be updated */
921 if (update_poll_flag) {
922 ret = update_apps_cmd_pollfd(nb_fd, current_nb_fd, &pollfd);
923 if (ret < 0) {
924 /* malloc failed so we quit */
925 goto error;
926 }
927
928 if (ust_cmd.sock != -1) {
929 /* Update pollfd with the new UST socket */
930 DBG("Adding sock %d to apps cmd pollfd", ust_cmd.sock);
931 pollfd[nb_fd - 1].fd = ust_cmd.sock;
932 pollfd[nb_fd - 1].events = POLLHUP | POLLNVAL | POLLERR;
933 ust_cmd.sock = -1;
934 }
935 }
936
937 DBG("Apps thread polling on %d fds", nb_fd);
938
939 /* Inifinite blocking call, waiting for transmission */
940 ret = poll(pollfd, nb_fd, -1);
941 if (ret < 0) {
942 perror("poll apps thread");
943 goto error;
944 }
945
946 /* Thread quit pipe has been closed. Killing thread. */
947 if (pollfd[0].revents == POLLNVAL) {
948 goto error;
949 } else {
950 /* apps_cmd_pipe pipe events */
951 switch (pollfd[1].revents) {
952 case POLLERR:
953 ERR("Apps command pipe poll error");
954 goto error;
955 case POLLIN:
956 /* Empty pipe */
957 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
958 if (ret < 0 || ret < sizeof(ust_cmd)) {
959 perror("read apps cmd pipe");
960 goto error;
961 }
962
963 /* Register applicaton to the session daemon */
964 ret = register_traceable_app(&ust_cmd.reg_msg, ust_cmd.sock);
965 if (ret < 0) {
966 /* Only critical ENOMEM error can be returned here */
967 goto error;
968 }
969
970 ret = ustctl_register_done(ust_cmd.sock);
971 if (ret < 0) {
972 /*
973 * If the registration is not possible, we simply unregister
974 * the apps and continue
975 */
976 unregister_traceable_app(ust_cmd.sock);
977 }
978 break;
979 }
980 }
981
982 current_nb_fd = nb_fd;
983 for (i = 2; i < current_nb_fd; i++) {
984 /* Apps socket is closed/hungup */
985 switch (pollfd[i].revents) {
986 case POLLERR:
987 case POLLHUP:
988 case POLLNVAL:
989 /* Pipe closed */
990 unregister_traceable_app(pollfd[i].fd);
991 /* Indicate to remove this fd from the pollfd */
992 pollfd[i].fd = -1;
993 nb_fd--;
994 break;
995 }
996 }
997
998 if (nb_fd != current_nb_fd) {
999 update_poll_flag = 1;
1000 }
1001 }
1002
1003 error:
1004 DBG("Application communication apps dying");
1005 close(apps_cmd_pipe[0]);
1006 close(apps_cmd_pipe[1]);
1007
1008 free(pollfd);
1009
1010 return NULL;
1011 }
1012
1013 /*
1014 * Dispatch request from the registration threads to the application
1015 * communication thread.
1016 */
1017 static void *thread_dispatch_ust_registration(void *data)
1018 {
1019 int ret;
1020 struct cds_wfq_node *node;
1021 struct ust_command *ust_cmd = NULL;
1022
1023 DBG("[thread] Dispatch UST command started");
1024
1025 while (!dispatch_thread_exit) {
1026 /* Atomically prepare the queue futex */
1027 futex_nto1_prepare(&ust_cmd_queue.futex);
1028
1029 do {
1030 /* Dequeue command for registration */
1031 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1032 if (node == NULL) {
1033 DBG("Waked up but nothing in the UST command queue");
1034 /* Continue thread execution */
1035 break;
1036 }
1037
1038 ust_cmd = caa_container_of(node, struct ust_command, node);
1039
1040 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1041 " gid:%d sock:%d name:%s (version %d.%d)",
1042 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1043 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1044 ust_cmd->sock, ust_cmd->reg_msg.name,
1045 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1046 /*
1047 * Inform apps thread of the new application registration. This
1048 * call is blocking so we can be assured that the data will be read
1049 * at some point in time or wait to the end of the world :)
1050 */
1051 ret = write(apps_cmd_pipe[1], ust_cmd,
1052 sizeof(struct ust_command));
1053 if (ret < 0) {
1054 perror("write apps cmd pipe");
1055 if (errno == EBADF) {
1056 /*
1057 * We can't inform the application thread to process
1058 * registration. We will exit or else application
1059 * registration will not occur and tracing will never
1060 * start.
1061 */
1062 goto error;
1063 }
1064 }
1065 free(ust_cmd);
1066 } while (node != NULL);
1067
1068 /* Futex wait on queue. Blocking call on futex() */
1069 futex_nto1_wait(&ust_cmd_queue.futex);
1070 }
1071
1072 error:
1073 DBG("Dispatch thread dying");
1074 return NULL;
1075 }
1076
1077 /*
1078 * This thread manage application registration.
1079 */
1080 static void *thread_registration_apps(void *data)
1081 {
1082 int sock = 0, ret;
1083 struct pollfd pollfd[2];
1084 /*
1085 * Get allocated in this thread, enqueued to a global queue, dequeued and
1086 * freed in the manage apps thread.
1087 */
1088 struct ust_command *ust_cmd = NULL;
1089
1090 DBG("[thread] Manage application registration started");
1091
1092 ret = lttcomm_listen_unix_sock(apps_sock);
1093 if (ret < 0) {
1094 goto error;
1095 }
1096
1097 /* First fd is always the quit pipe */
1098 pollfd[0].fd = thread_quit_pipe[0];
1099
1100 /* Apps socket */
1101 pollfd[1].fd = apps_sock;
1102 pollfd[1].events = POLLIN;
1103
1104 /* Notify all applications to register */
1105 ret = notify_ust_apps(1);
1106 if (ret < 0) {
1107 ERR("Failed to notify applications or create the wait shared memory.\n"
1108 "Execution continues but there might be problem for already running\n"
1109 "applications that wishes to register.");
1110 }
1111
1112 while (1) {
1113 DBG("Accepting application registration");
1114
1115 /* Inifinite blocking call, waiting for transmission */
1116 ret = poll(pollfd, 2, -1);
1117 if (ret < 0) {
1118 perror("poll register apps thread");
1119 goto error;
1120 }
1121
1122 /* Thread quit pipe has been closed. Killing thread. */
1123 if (pollfd[0].revents == POLLNVAL) {
1124 goto error;
1125 } else if (pollfd[1].revents == POLLERR) {
1126 ERR("Register apps socket poll error");
1127 goto error;
1128 }
1129
1130 sock = lttcomm_accept_unix_sock(apps_sock);
1131 if (sock < 0) {
1132 goto error;
1133 }
1134
1135 /* Create UST registration command for enqueuing */
1136 ust_cmd = malloc(sizeof(struct ust_command));
1137 if (ust_cmd == NULL) {
1138 perror("ust command malloc");
1139 goto error;
1140 }
1141
1142 /*
1143 * Using message-based transmissions to ensure we don't have to deal
1144 * with partially received messages.
1145 */
1146 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1147 sizeof(struct ust_register_msg));
1148 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1149 if (ret < 0) {
1150 perror("lttcomm_recv_unix_sock register apps");
1151 } else {
1152 ERR("Wrong size received on apps register");
1153 }
1154 free(ust_cmd);
1155 close(sock);
1156 continue;
1157 }
1158
1159 ust_cmd->sock = sock;
1160
1161 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1162 " gid:%d sock:%d name:%s (version %d.%d)",
1163 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1164 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1165 ust_cmd->sock, ust_cmd->reg_msg.name,
1166 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1167 /*
1168 * Lock free enqueue the registration request.
1169 * The red pill has been taken! This apps will be part of the *system*
1170 */
1171 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1172
1173 /*
1174 * Wake the registration queue futex.
1175 * Implicit memory barrier with the exchange in cds_wfq_enqueue.
1176 */
1177 futex_nto1_wake(&ust_cmd_queue.futex);
1178 }
1179
1180 error:
1181 DBG("UST Registration thread dying");
1182
1183 /* Notify that the registration thread is gone */
1184 notify_ust_apps(0);
1185
1186 close(apps_sock);
1187 close(sock);
1188
1189 unlink(apps_unix_sock_path);
1190
1191 return NULL;
1192 }
1193
1194 /*
1195 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
1196 * exec or it will fails.
1197 */
1198 static int spawn_kconsumerd_thread(void)
1199 {
1200 int ret;
1201
1202 /* Setup semaphore */
1203 sem_init(&kconsumerd_sem, 0, 0);
1204
1205 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
1206 if (ret != 0) {
1207 perror("pthread_create kconsumerd");
1208 goto error;
1209 }
1210
1211 /* Wait for the kconsumerd thread to be ready */
1212 sem_wait(&kconsumerd_sem);
1213
1214 if (kconsumerd_pid == 0) {
1215 ERR("Kconsumerd did not start");
1216 goto error;
1217 }
1218
1219 return 0;
1220
1221 error:
1222 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1223 return ret;
1224 }
1225
1226 /*
1227 * Join kernel consumer thread
1228 */
1229 static int join_kconsumerd_thread(void)
1230 {
1231 void *status;
1232 int ret;
1233
1234 if (kconsumerd_pid != 0) {
1235 ret = kill(kconsumerd_pid, SIGTERM);
1236 if (ret) {
1237 ERR("Error killing kconsumerd");
1238 return ret;
1239 }
1240 return pthread_join(kconsumerd_thread, &status);
1241 } else {
1242 return 0;
1243 }
1244 }
1245
1246 /*
1247 * Fork and exec a kernel consumer daemon (kconsumerd).
1248 *
1249 * Return pid if successful else -1.
1250 */
1251 static pid_t spawn_kconsumerd(void)
1252 {
1253 int ret;
1254 pid_t pid;
1255 const char *verbosity;
1256
1257 DBG("Spawning kconsumerd");
1258
1259 pid = fork();
1260 if (pid == 0) {
1261 /*
1262 * Exec kconsumerd.
1263 */
1264 if (opt_verbose > 1 || opt_verbose_kconsumerd) {
1265 verbosity = "--verbose";
1266 } else {
1267 verbosity = "--quiet";
1268 }
1269 execl(INSTALL_BIN_PATH "/ltt-kconsumerd", "ltt-kconsumerd", verbosity, NULL);
1270 if (errno != 0) {
1271 perror("kernel start consumer exec");
1272 }
1273 exit(EXIT_FAILURE);
1274 } else if (pid > 0) {
1275 ret = pid;
1276 goto error;
1277 } else {
1278 perror("kernel start consumer fork");
1279 ret = -errno;
1280 goto error;
1281 }
1282
1283 error:
1284 return ret;
1285 }
1286
1287 /*
1288 * Spawn the kconsumerd daemon and session daemon thread.
1289 */
1290 static int start_kconsumerd(void)
1291 {
1292 int ret;
1293
1294 pthread_mutex_lock(&kconsumerd_pid_mutex);
1295 if (kconsumerd_pid != 0) {
1296 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1297 goto end;
1298 }
1299
1300 ret = spawn_kconsumerd();
1301 if (ret < 0) {
1302 ERR("Spawning kconsumerd failed");
1303 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1304 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1305 goto error;
1306 }
1307
1308 /* Setting up the global kconsumerd_pid */
1309 kconsumerd_pid = ret;
1310 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1311
1312 DBG("Kconsumerd pid %d", ret);
1313
1314 DBG("Spawning kconsumerd thread");
1315 ret = spawn_kconsumerd_thread();
1316 if (ret < 0) {
1317 ERR("Fatal error spawning kconsumerd thread");
1318 goto error;
1319 }
1320
1321 end:
1322 return 0;
1323
1324 error:
1325 return ret;
1326 }
1327
1328 /*
1329 * modprobe_kernel_modules
1330 */
1331 static int modprobe_kernel_modules(void)
1332 {
1333 int ret = 0, i;
1334 char modprobe[256];
1335
1336 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1337 ret = snprintf(modprobe, sizeof(modprobe),
1338 "/sbin/modprobe %s%s",
1339 kernel_modules_list[i].required ? "" : "--quiet ",
1340 kernel_modules_list[i].name);
1341 if (ret < 0) {
1342 perror("snprintf modprobe");
1343 goto error;
1344 }
1345 modprobe[sizeof(modprobe) - 1] = '\0';
1346 ret = system(modprobe);
1347 if (ret == -1) {
1348 ERR("Unable to launch modprobe for module %s",
1349 kernel_modules_list[i].name);
1350 } else if (kernel_modules_list[i].required
1351 && WEXITSTATUS(ret) != 0) {
1352 ERR("Unable to load module %s",
1353 kernel_modules_list[i].name);
1354 } else {
1355 DBG("Modprobe successfully %s",
1356 kernel_modules_list[i].name);
1357 }
1358 }
1359
1360 error:
1361 return ret;
1362 }
1363
1364 /*
1365 * mount_debugfs
1366 */
1367 static int mount_debugfs(char *path)
1368 {
1369 int ret;
1370 char *type = "debugfs";
1371
1372 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1373 if (ret < 0) {
1374 goto error;
1375 }
1376
1377 ret = mount(type, path, type, 0, NULL);
1378 if (ret < 0) {
1379 perror("mount debugfs");
1380 goto error;
1381 }
1382
1383 DBG("Mounted debugfs successfully at %s", path);
1384
1385 error:
1386 return ret;
1387 }
1388
1389 /*
1390 * Setup necessary data for kernel tracer action.
1391 */
1392 static void init_kernel_tracer(void)
1393 {
1394 int ret;
1395 char *proc_mounts = "/proc/mounts";
1396 char line[256];
1397 char *debugfs_path = NULL, *lttng_path;
1398 FILE *fp;
1399
1400 /* Detect debugfs */
1401 fp = fopen(proc_mounts, "r");
1402 if (fp == NULL) {
1403 ERR("Unable to probe %s", proc_mounts);
1404 goto error;
1405 }
1406
1407 while (fgets(line, sizeof(line), fp) != NULL) {
1408 if (strstr(line, "debugfs") != NULL) {
1409 /* Remove first string */
1410 strtok(line, " ");
1411 /* Dup string here so we can reuse line later on */
1412 debugfs_path = strdup(strtok(NULL, " "));
1413 DBG("Got debugfs path : %s", debugfs_path);
1414 break;
1415 }
1416 }
1417
1418 fclose(fp);
1419
1420 /* Mount debugfs if needded */
1421 if (debugfs_path == NULL) {
1422 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1423 if (ret < 0) {
1424 perror("asprintf debugfs path");
1425 goto error;
1426 }
1427 ret = mount_debugfs(debugfs_path);
1428 if (ret < 0) {
1429 goto error;
1430 }
1431 }
1432
1433 /* Modprobe lttng kernel modules */
1434 ret = modprobe_kernel_modules();
1435 if (ret < 0) {
1436 goto error;
1437 }
1438
1439 /* Setup lttng kernel path */
1440 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1441 if (ret < 0) {
1442 perror("asprintf lttng path");
1443 goto error;
1444 }
1445
1446 /* Open debugfs lttng */
1447 kernel_tracer_fd = open(lttng_path, O_RDWR);
1448 if (kernel_tracer_fd < 0) {
1449 DBG("Failed to open %s", lttng_path);
1450 goto error;
1451 }
1452
1453 free(lttng_path);
1454 free(debugfs_path);
1455 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1456 return;
1457
1458 error:
1459 if (lttng_path) {
1460 free(lttng_path);
1461 }
1462 if (debugfs_path) {
1463 free(debugfs_path);
1464 }
1465 WARN("No kernel tracer available");
1466 kernel_tracer_fd = 0;
1467 return;
1468 }
1469
1470 /*
1471 * Start tracing by creating trace directory and sending FDs to the kernel
1472 * consumer.
1473 */
1474 static int start_kernel_trace(struct ltt_kernel_session *session)
1475 {
1476 int ret = 0;
1477
1478 if (session->kconsumer_fds_sent == 0) {
1479 /*
1480 * Assign default kernel consumer if no consumer assigned to the kernel
1481 * session. At this point, it's NOT suppose to be 0 but this is an extra
1482 * security check.
1483 */
1484 if (session->consumer_fd == 0) {
1485 session->consumer_fd = kconsumerd_cmd_sock;
1486 }
1487
1488 ret = send_kconsumerd_fds(session);
1489 if (ret < 0) {
1490 ERR("Send kconsumerd fds failed");
1491 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1492 goto error;
1493 }
1494
1495 session->kconsumer_fds_sent = 1;
1496 }
1497
1498 error:
1499 return ret;
1500 }
1501
1502 /*
1503 * Notify kernel thread to update it's pollfd.
1504 */
1505 static int notify_kernel_pollfd(void)
1506 {
1507 int ret;
1508
1509 /* Inform kernel thread of the new kernel channel */
1510 ret = write(kernel_poll_pipe[1], "!", 1);
1511 if (ret < 0) {
1512 perror("write kernel poll pipe");
1513 }
1514
1515 return ret;
1516 }
1517
1518 /*
1519 * Allocate a channel structure and fill it.
1520 */
1521 static struct lttng_channel *init_default_channel(enum lttng_domain_type domain_type,
1522 char *name)
1523 {
1524 struct lttng_channel *chan;
1525
1526 chan = malloc(sizeof(struct lttng_channel));
1527 if (chan == NULL) {
1528 perror("init channel malloc");
1529 goto error;
1530 }
1531
1532 if (snprintf(chan->name, NAME_MAX, "%s", name) < 0) {
1533 perror("snprintf channel name");
1534 goto error;
1535 }
1536
1537 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1538 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1539 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1540
1541 switch (domain_type) {
1542 case LTTNG_DOMAIN_KERNEL:
1543 chan->attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
1544 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1545 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1546 break;
1547 /* TODO: add UST */
1548 default:
1549 goto error; /* Not implemented */
1550 }
1551
1552 return chan;
1553
1554 error:
1555 free(chan);
1556 return NULL;
1557 }
1558
1559 /*
1560 * Create an UST session and add it to the session ust list.
1561 */
1562 static int create_ust_session(pid_t pid, struct ltt_session *session)
1563 {
1564 int ret = -1;
1565 struct ltt_ust_session *lus;
1566
1567 DBG("Creating UST session");
1568
1569 lus = trace_ust_create_session(session->path, pid);
1570 if (lus == NULL) {
1571 goto error;
1572 }
1573
1574 ret = mkdir_recursive(lus->path, S_IRWXU | S_IRWXG,
1575 geteuid(), allowed_group());
1576 if (ret < 0) {
1577 if (ret != -EEXIST) {
1578 ERR("Trace directory creation error");
1579 goto error;
1580 }
1581 }
1582
1583 /* Create session on the UST tracer */
1584 ret = ustctl_create_session(lus);
1585 if (ret < 0) {
1586 goto error;
1587 }
1588
1589 return 0;
1590
1591 error:
1592 free(lus);
1593 return ret;
1594 }
1595
1596 /*
1597 * Create a kernel tracer session then create the default channel.
1598 */
1599 static int create_kernel_session(struct ltt_session *session)
1600 {
1601 int ret;
1602
1603 DBG("Creating kernel session");
1604
1605 ret = kernel_create_session(session, kernel_tracer_fd);
1606 if (ret < 0) {
1607 ret = LTTCOMM_KERN_SESS_FAIL;
1608 goto error;
1609 }
1610
1611 /* Set kernel consumer socket fd */
1612 if (kconsumerd_cmd_sock) {
1613 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
1614 }
1615
1616 ret = mkdir_recursive(session->kernel_session->trace_path,
1617 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1618 if (ret < 0) {
1619 if (ret != -EEXIST) {
1620 ERR("Trace directory creation error");
1621 goto error;
1622 }
1623 }
1624
1625 error:
1626 return ret;
1627 }
1628
1629 /*
1630 * Using the session list, filled a lttng_session array to send back to the
1631 * client for session listing.
1632 *
1633 * The session list lock MUST be acquired before calling this function. Use
1634 * lock_session_list() and unlock_session_list().
1635 */
1636 static void list_lttng_sessions(struct lttng_session *sessions)
1637 {
1638 int i = 0;
1639 struct ltt_session *session;
1640
1641 DBG("Getting all available session");
1642 /*
1643 * Iterate over session list and append data after the control struct in
1644 * the buffer.
1645 */
1646 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1647 strncpy(sessions[i].path, session->path, PATH_MAX);
1648 sessions[i].path[PATH_MAX - 1] = '\0';
1649 strncpy(sessions[i].name, session->name, NAME_MAX);
1650 sessions[i].name[NAME_MAX - 1] = '\0';
1651 i++;
1652 }
1653 }
1654
1655 /*
1656 * Fill lttng_channel array of all channels.
1657 */
1658 static void list_lttng_channels(struct ltt_session *session,
1659 struct lttng_channel *channels)
1660 {
1661 int i = 0;
1662 struct ltt_kernel_channel *kchan;
1663
1664 DBG("Listing channels for session %s", session->name);
1665
1666 /* Kernel channels */
1667 if (session->kernel_session != NULL) {
1668 cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) {
1669 /* Copy lttng_channel struct to array */
1670 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1671 channels[i].enabled = kchan->enabled;
1672 i++;
1673 }
1674 }
1675
1676 /* TODO: Missing UST listing */
1677 }
1678
1679 /*
1680 * Fill lttng_event array of all events in the channel.
1681 */
1682 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1683 struct lttng_event *events)
1684 {
1685 /*
1686 * TODO: This is ONLY kernel. Need UST support.
1687 */
1688 int i = 0;
1689 struct ltt_kernel_event *event;
1690
1691 DBG("Listing events for channel %s", kchan->channel->name);
1692
1693 /* Kernel channels */
1694 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1695 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1696 events[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1697 events[i].enabled = event->enabled;
1698 switch (event->event->instrumentation) {
1699 case LTTNG_KERNEL_TRACEPOINT:
1700 events[i].type = LTTNG_EVENT_TRACEPOINT;
1701 break;
1702 case LTTNG_KERNEL_KPROBE:
1703 case LTTNG_KERNEL_KRETPROBE:
1704 events[i].type = LTTNG_EVENT_PROBE;
1705 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1706 sizeof(struct lttng_kernel_kprobe));
1707 break;
1708 case LTTNG_KERNEL_FUNCTION:
1709 events[i].type = LTTNG_EVENT_FUNCTION;
1710 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1711 sizeof(struct lttng_kernel_function));
1712 break;
1713 }
1714 i++;
1715 }
1716 }
1717
1718 /*
1719 * Process the command requested by the lttng client within the command
1720 * context structure. This function make sure that the return structure (llm)
1721 * is set and ready for transmission before returning.
1722 *
1723 * Return any error encountered or 0 for success.
1724 */
1725 static int process_client_msg(struct command_ctx *cmd_ctx)
1726 {
1727 int ret = LTTCOMM_OK;
1728
1729 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1730
1731 /*
1732 * Commands that DO NOT need a session.
1733 */
1734 switch (cmd_ctx->lsm->cmd_type) {
1735 case LTTNG_CREATE_SESSION:
1736 case LTTNG_LIST_SESSIONS:
1737 case LTTNG_LIST_TRACEPOINTS:
1738 case LTTNG_CALIBRATE:
1739 break;
1740 default:
1741 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
1742 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session.name);
1743 if (cmd_ctx->session == NULL) {
1744 /* If session name not found */
1745 if (cmd_ctx->lsm->session.name != NULL) {
1746 ret = LTTCOMM_SESS_NOT_FOUND;
1747 } else { /* If no session name specified */
1748 ret = LTTCOMM_SELECT_SESS;
1749 }
1750 goto error;
1751 } else {
1752 /* Acquire lock for the session */
1753 lock_session(cmd_ctx->session);
1754 }
1755 break;
1756 }
1757
1758 /*
1759 * Check domain type for specific "pre-action".
1760 */
1761 switch (cmd_ctx->lsm->domain.type) {
1762 case LTTNG_DOMAIN_KERNEL:
1763 /* Kernel tracer check */
1764 if (kernel_tracer_fd == 0) {
1765 init_kernel_tracer();
1766 if (kernel_tracer_fd == 0) {
1767 ret = LTTCOMM_KERN_NA;
1768 goto error;
1769 }
1770 }
1771 /* Need a session for kernel command */
1772 switch (cmd_ctx->lsm->cmd_type) {
1773 case LTTNG_CALIBRATE:
1774 case LTTNG_CREATE_SESSION:
1775 case LTTNG_LIST_SESSIONS:
1776 case LTTNG_LIST_TRACEPOINTS:
1777 break;
1778 default:
1779 if (cmd_ctx->session->kernel_session == NULL) {
1780 ret = create_kernel_session(cmd_ctx->session);
1781 if (ret < 0) {
1782 ret = LTTCOMM_KERN_SESS_FAIL;
1783 goto error;
1784 }
1785 /* Start the kernel consumer daemon */
1786 if (kconsumerd_pid == 0 &&
1787 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
1788 ret = start_kconsumerd();
1789 if (ret < 0) {
1790 goto error;
1791 }
1792 }
1793 }
1794 }
1795 break;
1796 case LTTNG_DOMAIN_UST_PID:
1797 break;
1798 default:
1799 break;
1800 }
1801
1802 /* Process by command type */
1803 switch (cmd_ctx->lsm->cmd_type) {
1804 case LTTNG_ADD_CONTEXT:
1805 {
1806 struct lttng_kernel_context kctx;
1807
1808 /* Setup lttng message with no payload */
1809 ret = setup_lttng_msg(cmd_ctx, 0);
1810 if (ret < 0) {
1811 goto setup_error;
1812 }
1813
1814 switch (cmd_ctx->lsm->domain.type) {
1815 case LTTNG_DOMAIN_KERNEL:
1816 /* Create Kernel context */
1817 kctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1818 kctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1819 kctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1820 strncpy(kctx.u.perf_counter.name,
1821 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1822 LTTNG_SYMBOL_NAME_LEN);
1823 kctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1824
1825 /* Add kernel context to kernel tracer. See context.c */
1826 ret = add_kernel_context(cmd_ctx->session->kernel_session, &kctx,
1827 cmd_ctx->lsm->u.context.event_name,
1828 cmd_ctx->lsm->u.context.channel_name);
1829 if (ret != LTTCOMM_OK) {
1830 goto error;
1831 }
1832 break;
1833 default:
1834 /* TODO: Userspace tracing */
1835 ret = LTTCOMM_NOT_IMPLEMENTED;
1836 goto error;
1837 }
1838
1839 ret = LTTCOMM_OK;
1840 break;
1841 }
1842 case LTTNG_DISABLE_CHANNEL:
1843 {
1844 struct ltt_kernel_channel *kchan;
1845
1846 /* Setup lttng message with no payload */
1847 ret = setup_lttng_msg(cmd_ctx, 0);
1848 if (ret < 0) {
1849 goto setup_error;
1850 }
1851
1852 switch (cmd_ctx->lsm->domain.type) {
1853 case LTTNG_DOMAIN_KERNEL:
1854 kchan = trace_kernel_get_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1855 cmd_ctx->session->kernel_session);
1856 if (kchan == NULL) {
1857 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1858 goto error;
1859 } else if (kchan->enabled == 1) {
1860 ret = kernel_disable_channel(kchan);
1861 if (ret < 0) {
1862 if (ret != EEXIST) {
1863 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1864 }
1865 goto error;
1866 }
1867 }
1868 kernel_wait_quiescent(kernel_tracer_fd);
1869 break;
1870 default:
1871 /* TODO: Userspace tracing */
1872 ret = LTTCOMM_NOT_IMPLEMENTED;
1873 goto error;
1874 }
1875
1876 ret = LTTCOMM_OK;
1877 break;
1878 }
1879 case LTTNG_DISABLE_EVENT:
1880 {
1881 struct ltt_kernel_channel *kchan;
1882 struct ltt_kernel_event *kevent;
1883
1884 /* Setup lttng message with no payload */
1885 ret = setup_lttng_msg(cmd_ctx, 0);
1886 if (ret < 0) {
1887 goto setup_error;
1888 }
1889
1890 switch (cmd_ctx->lsm->domain.type) {
1891 case LTTNG_DOMAIN_KERNEL:
1892 kchan = trace_kernel_get_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1893 cmd_ctx->session->kernel_session);
1894 if (kchan == NULL) {
1895 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1896 goto error;
1897 }
1898
1899 kevent = trace_kernel_get_event_by_name(cmd_ctx->lsm->u.disable.name, kchan);
1900 if (kevent != NULL) {
1901 DBG("Disabling kernel event %s for channel %s.", kevent->event->name,
1902 kchan->channel->name);
1903 ret = kernel_disable_event(kevent);
1904 if (ret < 0) {
1905 ret = LTTCOMM_KERN_ENABLE_FAIL;
1906 goto error;
1907 }
1908 }
1909
1910 kernel_wait_quiescent(kernel_tracer_fd);
1911 break;
1912 default:
1913 /* TODO: Userspace tracing */
1914 ret = LTTCOMM_NOT_IMPLEMENTED;
1915 goto error;
1916 }
1917
1918 ret = LTTCOMM_OK;
1919 break;
1920 }
1921 case LTTNG_DISABLE_ALL_EVENT:
1922 {
1923 struct ltt_kernel_channel *kchan;
1924 struct ltt_kernel_event *kevent;
1925
1926 /* Setup lttng message with no payload */
1927 ret = setup_lttng_msg(cmd_ctx, 0);
1928 if (ret < 0) {
1929 goto setup_error;
1930 }
1931
1932 switch (cmd_ctx->lsm->domain.type) {
1933 case LTTNG_DOMAIN_KERNEL:
1934 DBG("Disabling all enabled kernel events");
1935 kchan = trace_kernel_get_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1936 cmd_ctx->session->kernel_session);
1937 if (kchan == NULL) {
1938 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1939 goto error;
1940 }
1941
1942 /* For each event in the kernel session */
1943 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1944 DBG("Disabling kernel event %s for channel %s.",
1945 kevent->event->name, kchan->channel->name);
1946 ret = kernel_disable_event(kevent);
1947 if (ret < 0) {
1948 continue;
1949 }
1950 }
1951
1952 /* Quiescent wait after event disable */
1953 kernel_wait_quiescent(kernel_tracer_fd);
1954 break;
1955 default:
1956 /* TODO: Userspace tracing */
1957 ret = LTTCOMM_NOT_IMPLEMENTED;
1958 goto error;
1959 }
1960
1961 ret = LTTCOMM_OK;
1962 break;
1963 }
1964 case LTTNG_ENABLE_CHANNEL:
1965 {
1966 struct ltt_kernel_channel *kchan;
1967
1968 /* Setup lttng message with no payload */
1969 ret = setup_lttng_msg(cmd_ctx, 0);
1970 if (ret < 0) {
1971 goto setup_error;
1972 }
1973
1974 switch (cmd_ctx->lsm->domain.type) {
1975 case LTTNG_DOMAIN_KERNEL:
1976 kchan = trace_kernel_get_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1977 cmd_ctx->session->kernel_session);
1978 if (kchan == NULL) {
1979 /* Channel not found, creating it */
1980 DBG("Creating kernel channel");
1981
1982 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1983 &cmd_ctx->lsm->u.channel.chan,
1984 cmd_ctx->session->kernel_session->trace_path);
1985 if (ret < 0) {
1986 ret = LTTCOMM_KERN_CHAN_FAIL;
1987 goto error;
1988 }
1989
1990 /* Notify kernel thread that there is a new channel */
1991 ret = notify_kernel_pollfd();
1992 if (ret < 0) {
1993 ret = LTTCOMM_FATAL;
1994 goto error;
1995 }
1996 } else if (kchan->enabled == 0) {
1997 ret = kernel_enable_channel(kchan);
1998 if (ret < 0) {
1999 if (ret != EEXIST) {
2000 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
2001 }
2002 goto error;
2003 }
2004 }
2005
2006 kernel_wait_quiescent(kernel_tracer_fd);
2007 break;
2008 case LTTNG_DOMAIN_UST_PID:
2009
2010 break;
2011 default:
2012 ret = LTTCOMM_NOT_IMPLEMENTED;
2013 goto error;
2014 }
2015
2016 ret = LTTCOMM_OK;
2017 break;
2018 }
2019 case LTTNG_ENABLE_EVENT:
2020 {
2021 char *channel_name;
2022 struct ltt_kernel_channel *kchan;
2023 struct ltt_kernel_event *kevent;
2024 struct lttng_channel *chan;
2025
2026 /* Setup lttng message with no payload */
2027 ret = setup_lttng_msg(cmd_ctx, 0);
2028 if (ret < 0) {
2029 goto setup_error;
2030 }
2031
2032 channel_name = cmd_ctx->lsm->u.enable.channel_name;
2033
2034 switch (cmd_ctx->lsm->domain.type) {
2035 case LTTNG_DOMAIN_KERNEL:
2036 kchan = trace_kernel_get_channel_by_name(channel_name,
2037 cmd_ctx->session->kernel_session);
2038 if (kchan == NULL) {
2039 DBG("Channel not found. Creating channel %s", channel_name);
2040
2041 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
2042 if (chan == NULL) {
2043 ret = LTTCOMM_FATAL;
2044 goto error;
2045 }
2046
2047 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
2048 chan, cmd_ctx->session->kernel_session->trace_path);
2049 if (ret < 0) {
2050 ret = LTTCOMM_KERN_CHAN_FAIL;
2051 goto error;
2052 }
2053 kchan = trace_kernel_get_channel_by_name(channel_name,
2054 cmd_ctx->session->kernel_session);
2055 if (kchan == NULL) {
2056 ERR("Channel %s not found after creation. Internal error, giving up.",
2057 channel_name);
2058 ret = LTTCOMM_FATAL;
2059 goto error;
2060 }
2061 }
2062
2063 kevent = trace_kernel_get_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
2064 if (kevent == NULL) {
2065 DBG("Creating kernel event %s for channel %s.",
2066 cmd_ctx->lsm->u.enable.event.name, channel_name);
2067 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
2068 } else {
2069 DBG("Enabling kernel event %s for channel %s.",
2070 kevent->event->name, channel_name);
2071 ret = kernel_enable_event(kevent);
2072 if (ret == -EEXIST) {
2073 ret = LTTCOMM_KERN_EVENT_EXIST;
2074 goto error;
2075 }
2076 }
2077
2078 if (ret < 0) {
2079 ret = LTTCOMM_KERN_ENABLE_FAIL;
2080 goto error;
2081 }
2082
2083 kernel_wait_quiescent(kernel_tracer_fd);
2084 break;
2085 default:
2086 /* TODO: Userspace tracing */
2087 ret = LTTCOMM_NOT_IMPLEMENTED;
2088 goto error;
2089 }
2090 ret = LTTCOMM_OK;
2091 break;
2092 }
2093 case LTTNG_ENABLE_ALL_EVENT:
2094 {
2095 int size, i;
2096 char *channel_name;
2097 struct ltt_kernel_channel *kchan;
2098 struct ltt_kernel_event *kevent;
2099 struct lttng_event *event_list;
2100 struct lttng_channel *chan;
2101
2102 /* Setup lttng message with no payload */
2103 ret = setup_lttng_msg(cmd_ctx, 0);
2104 if (ret < 0) {
2105 goto setup_error;
2106 }
2107
2108 DBG("Enabling all kernel event");
2109
2110 channel_name = cmd_ctx->lsm->u.enable.channel_name;
2111
2112 switch (cmd_ctx->lsm->domain.type) {
2113 case LTTNG_DOMAIN_KERNEL:
2114 kchan = trace_kernel_get_channel_by_name(channel_name,
2115 cmd_ctx->session->kernel_session);
2116 if (kchan == NULL) {
2117 DBG("Channel not found. Creating channel %s", channel_name);
2118
2119 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
2120 if (chan == NULL) {
2121 ret = LTTCOMM_FATAL;
2122 goto error;
2123 }
2124
2125 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
2126 chan, cmd_ctx->session->kernel_session->trace_path);
2127 if (ret < 0) {
2128 ret = LTTCOMM_KERN_CHAN_FAIL;
2129 goto error;
2130 }
2131 kchan = trace_kernel_get_channel_by_name(channel_name,
2132 cmd_ctx->session->kernel_session);
2133 if (kchan == NULL) {
2134 ERR("Channel %s not found after creation. Internal error, giving up.",
2135 channel_name);
2136 ret = LTTCOMM_FATAL;
2137 goto error;
2138 }
2139 }
2140
2141 /* For each event in the kernel session */
2142 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
2143 DBG("Enabling kernel event %s for channel %s.",
2144 kevent->event->name, channel_name);
2145 ret = kernel_enable_event(kevent);
2146 if (ret < 0) {
2147 continue;
2148 }
2149 }
2150
2151 size = kernel_list_events(kernel_tracer_fd, &event_list);
2152 if (size < 0) {
2153 ret = LTTCOMM_KERN_LIST_FAIL;
2154 goto error;
2155 }
2156
2157 for (i = 0; i < size; i++) {
2158 kevent = trace_kernel_get_event_by_name(event_list[i].name, kchan);
2159 if (kevent == NULL) {
2160 /* Default event type for enable all */
2161 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
2162 /* Enable each single tracepoint event */
2163 ret = kernel_create_event(&event_list[i], kchan);
2164 if (ret < 0) {
2165 /* Ignore error here and continue */
2166 }
2167 }
2168 }
2169
2170 free(event_list);
2171
2172 /* Quiescent wait after event enable */
2173 kernel_wait_quiescent(kernel_tracer_fd);
2174 break;
2175 default:
2176 /* TODO: Userspace tracing */
2177 ret = LTTCOMM_NOT_IMPLEMENTED;
2178 goto error;
2179 }
2180
2181 ret = LTTCOMM_OK;
2182 break;
2183 }
2184 case LTTNG_LIST_TRACEPOINTS:
2185 {
2186 struct lttng_event *events;
2187 ssize_t nb_events = 0;
2188
2189 switch (cmd_ctx->lsm->domain.type) {
2190 case LTTNG_DOMAIN_KERNEL:
2191 DBG("Listing kernel events");
2192 nb_events = kernel_list_events(kernel_tracer_fd, &events);
2193 if (nb_events < 0) {
2194 ret = LTTCOMM_KERN_LIST_FAIL;
2195 goto error;
2196 }
2197 break;
2198 default:
2199 /* TODO: Userspace listing */
2200 ret = LTTCOMM_NOT_IMPLEMENTED;
2201 break;
2202 }
2203
2204 /*
2205 * Setup lttng message with payload size set to the event list size in
2206 * bytes and then copy list into the llm payload.
2207 */
2208 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
2209 if (ret < 0) {
2210 free(events);
2211 goto setup_error;
2212 }
2213
2214 /* Copy event list into message payload */
2215 memcpy(cmd_ctx->llm->payload, events,
2216 sizeof(struct lttng_event) * nb_events);
2217
2218 free(events);
2219
2220 ret = LTTCOMM_OK;
2221 break;
2222 }
2223 case LTTNG_START_TRACE:
2224 {
2225 struct ltt_kernel_channel *chan;
2226
2227 /* Setup lttng message with no payload */
2228 ret = setup_lttng_msg(cmd_ctx, 0);
2229 if (ret < 0) {
2230 goto setup_error;
2231 }
2232
2233 /* Kernel tracing */
2234 if (cmd_ctx->session->kernel_session != NULL) {
2235 if (cmd_ctx->session->kernel_session->metadata == NULL) {
2236 DBG("Open kernel metadata");
2237 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
2238 cmd_ctx->session->kernel_session->trace_path);
2239 if (ret < 0) {
2240 ret = LTTCOMM_KERN_META_FAIL;
2241 goto error;
2242 }
2243 }
2244
2245 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
2246 DBG("Opening kernel metadata stream");
2247 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
2248 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
2249 if (ret < 0) {
2250 ERR("Kernel create metadata stream failed");
2251 ret = LTTCOMM_KERN_STREAM_FAIL;
2252 goto error;
2253 }
2254 }
2255 }
2256
2257 /* For each channel */
2258 cds_list_for_each_entry(chan,
2259 &cmd_ctx->session->kernel_session->channel_list.head, list) {
2260 if (chan->stream_count == 0) {
2261 ret = kernel_open_channel_stream(chan);
2262 if (ret < 0) {
2263 ERR("Kernel create channel stream failed");
2264 ret = LTTCOMM_KERN_STREAM_FAIL;
2265 goto error;
2266 }
2267 /* Update the stream global counter */
2268 cmd_ctx->session->kernel_session->stream_count_global += ret;
2269 }
2270 }
2271
2272 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
2273 if (ret < 0) {
2274 ret = LTTCOMM_KERN_START_FAIL;
2275 goto error;
2276 }
2277
2278 DBG("Start kernel tracing");
2279 ret = kernel_start_session(cmd_ctx->session->kernel_session);
2280 if (ret < 0) {
2281 ERR("Kernel start session failed");
2282 ret = LTTCOMM_KERN_START_FAIL;
2283 goto error;
2284 }
2285
2286 /* Quiescent wait after starting trace */
2287 kernel_wait_quiescent(kernel_tracer_fd);
2288 }
2289
2290 /* TODO: Start all UST traces */
2291
2292 ret = LTTCOMM_OK;
2293 break;
2294 }
2295 case LTTNG_STOP_TRACE:
2296 {
2297 struct ltt_kernel_channel *chan;
2298 /* Setup lttng message with no payload */
2299 ret = setup_lttng_msg(cmd_ctx, 0);
2300 if (ret < 0) {
2301 goto setup_error;
2302 }
2303
2304 /* Kernel tracer */
2305 if (cmd_ctx->session->kernel_session != NULL) {
2306 DBG("Stop kernel tracing");
2307
2308 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
2309 if (ret < 0) {
2310 ERR("Kernel metadata flush failed");
2311 }
2312
2313 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
2314 ret = kernel_flush_buffer(chan);
2315 if (ret < 0) {
2316 ERR("Kernel flush buffer error");
2317 }
2318 }
2319
2320 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
2321 if (ret < 0) {
2322 ERR("Kernel stop session failed");
2323 ret = LTTCOMM_KERN_STOP_FAIL;
2324 goto error;
2325 }
2326
2327 /* Quiescent wait after stopping trace */
2328 kernel_wait_quiescent(kernel_tracer_fd);
2329 }
2330
2331 /* TODO : User-space tracer */
2332
2333 ret = LTTCOMM_OK;
2334 break;
2335 }
2336 case LTTNG_CREATE_SESSION:
2337 {
2338 /* Setup lttng message with no payload */
2339 ret = setup_lttng_msg(cmd_ctx, 0);
2340 if (ret < 0) {
2341 goto setup_error;
2342 }
2343
2344 ret = create_session(cmd_ctx->lsm->session.name, cmd_ctx->lsm->session.path);
2345 if (ret < 0) {
2346 if (ret == -EEXIST) {
2347 ret = LTTCOMM_EXIST_SESS;
2348 } else {
2349 ret = LTTCOMM_FATAL;
2350 }
2351 goto error;
2352 }
2353
2354 ret = LTTCOMM_OK;
2355 break;
2356 }
2357 case LTTNG_DESTROY_SESSION:
2358 {
2359 /* Setup lttng message with no payload */
2360 ret = setup_lttng_msg(cmd_ctx, 0);
2361 if (ret < 0) {
2362 goto setup_error;
2363 }
2364
2365 /* Clean kernel session teardown */
2366 teardown_kernel_session(cmd_ctx->session);
2367
2368 ret = destroy_session(cmd_ctx->lsm->session.name);
2369 if (ret < 0) {
2370 ret = LTTCOMM_FATAL;
2371 goto error;
2372 }
2373
2374 /*
2375 * Must notify the kernel thread here to update it's pollfd in order to
2376 * remove the channel(s)' fd just destroyed.
2377 */
2378 ret = notify_kernel_pollfd();
2379 if (ret < 0) {
2380 ret = LTTCOMM_FATAL;
2381 goto error;
2382 }
2383
2384 ret = LTTCOMM_OK;
2385 break;
2386 }
2387 case LTTNG_LIST_DOMAINS:
2388 {
2389 size_t nb_dom = 0;
2390
2391 if (cmd_ctx->session->kernel_session != NULL) {
2392 nb_dom++;
2393 }
2394
2395 nb_dom += cmd_ctx->session->ust_session_list.count;
2396
2397 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_domain) * nb_dom);
2398 if (ret < 0) {
2399 goto setup_error;
2400 }
2401
2402 ((struct lttng_domain *)(cmd_ctx->llm->payload))[0].type =
2403 LTTNG_DOMAIN_KERNEL;
2404
2405 /* TODO: User-space tracer domain support */
2406 ret = LTTCOMM_OK;
2407 break;
2408 }
2409 case LTTNG_LIST_CHANNELS:
2410 {
2411 /*
2412 * TODO: Only kernel channels are listed here. UST listing
2413 * is needed on lttng-ust 2.0 release.
2414 */
2415 size_t nb_chan = 0;
2416 if (cmd_ctx->session->kernel_session != NULL) {
2417 nb_chan += cmd_ctx->session->kernel_session->channel_count;
2418 }
2419
2420 ret = setup_lttng_msg(cmd_ctx,
2421 sizeof(struct lttng_channel) * nb_chan);
2422 if (ret < 0) {
2423 goto setup_error;
2424 }
2425
2426 list_lttng_channels(cmd_ctx->session,
2427 (struct lttng_channel *)(cmd_ctx->llm->payload));
2428
2429 ret = LTTCOMM_OK;
2430 break;
2431 }
2432 case LTTNG_LIST_EVENTS:
2433 {
2434 /*
2435 * TODO: Only kernel events are listed here. UST listing
2436 * is needed on lttng-ust 2.0 release.
2437 */
2438 size_t nb_event = 0;
2439 struct ltt_kernel_channel *kchan = NULL;
2440
2441 if (cmd_ctx->session->kernel_session != NULL) {
2442 kchan = trace_kernel_get_channel_by_name(cmd_ctx->lsm->u.list.channel_name,
2443 cmd_ctx->session->kernel_session);
2444 if (kchan == NULL) {
2445 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2446 goto error;
2447 }
2448 nb_event += kchan->event_count;
2449 }
2450
2451 ret = setup_lttng_msg(cmd_ctx,
2452 sizeof(struct lttng_event) * nb_event);
2453 if (ret < 0) {
2454 goto setup_error;
2455 }
2456
2457 DBG("Listing events (%zu events)", nb_event);
2458
2459 list_lttng_events(kchan,
2460 (struct lttng_event *)(cmd_ctx->llm->payload));
2461
2462 ret = LTTCOMM_OK;
2463 break;
2464 }
2465 case LTTNG_LIST_SESSIONS:
2466 {
2467 lock_session_list();
2468
2469 if (session_list_ptr->count == 0) {
2470 ret = LTTCOMM_NO_SESSION;
2471 unlock_session_list();
2472 goto error;
2473 }
2474
2475 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
2476 session_list_ptr->count);
2477 if (ret < 0) {
2478 unlock_session_list();
2479 goto setup_error;
2480 }
2481
2482 /* Filled the session array */
2483 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
2484
2485 unlock_session_list();
2486
2487 ret = LTTCOMM_OK;
2488 break;
2489 }
2490 case LTTNG_CALIBRATE:
2491 {
2492 /* Setup lttng message with no payload */
2493 ret = setup_lttng_msg(cmd_ctx, 0);
2494 if (ret < 0) {
2495 goto setup_error;
2496 }
2497
2498 switch (cmd_ctx->lsm->domain.type) {
2499 case LTTNG_DOMAIN_KERNEL:
2500 {
2501 struct lttng_kernel_calibrate kcalibrate;
2502
2503 kcalibrate.type = cmd_ctx->lsm->u.calibrate.type;
2504 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2505 if (ret < 0) {
2506 ret = LTTCOMM_KERN_ENABLE_FAIL;
2507 goto error;
2508 }
2509 break;
2510 }
2511 default:
2512 /* TODO: Userspace tracing */
2513 ret = LTTCOMM_NOT_IMPLEMENTED;
2514 goto error;
2515 }
2516 ret = LTTCOMM_OK;
2517 break;
2518 }
2519 case LTTNG_REGISTER_CONSUMER:
2520 {
2521 int sock;
2522
2523 /* Setup lttng message with no payload */
2524 ret = setup_lttng_msg(cmd_ctx, 0);
2525 if (ret < 0) {
2526 goto setup_error;
2527 }
2528
2529 switch (cmd_ctx->lsm->domain.type) {
2530 case LTTNG_DOMAIN_KERNEL:
2531 {
2532 /* Can't register a consumer if there is already one */
2533 if (cmd_ctx->session->kernel_session->consumer_fd != 0) {
2534 ret = LTTCOMM_CONNECT_FAIL;
2535 goto error;
2536 }
2537
2538 sock = lttcomm_connect_unix_sock(cmd_ctx->lsm->u.reg.path);
2539 if (sock < 0) {
2540 ret = LTTCOMM_CONNECT_FAIL;
2541 goto error;
2542 }
2543
2544 cmd_ctx->session->kernel_session->consumer_fd = sock;
2545 break;
2546 }
2547 default:
2548 /* TODO: Userspace tracing */
2549 ret = LTTCOMM_NOT_IMPLEMENTED;
2550 goto error;
2551 }
2552
2553 ret = LTTCOMM_OK;
2554 break;
2555 }
2556
2557 default:
2558 /* Undefined command */
2559 ret = setup_lttng_msg(cmd_ctx, 0);
2560 if (ret < 0) {
2561 goto setup_error;
2562 }
2563
2564 ret = LTTCOMM_UND;
2565 break;
2566 }
2567
2568 /* Set return code */
2569 cmd_ctx->llm->ret_code = ret;
2570
2571 if (cmd_ctx->session) {
2572 unlock_session(cmd_ctx->session);
2573 }
2574
2575 return ret;
2576
2577 error:
2578 if (cmd_ctx->llm == NULL) {
2579 DBG("Missing llm structure. Allocating one.");
2580 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2581 goto setup_error;
2582 }
2583 }
2584 /* Notify client of error */
2585 cmd_ctx->llm->ret_code = ret;
2586
2587 setup_error:
2588 if (cmd_ctx->session) {
2589 unlock_session(cmd_ctx->session);
2590 }
2591 return ret;
2592 }
2593
2594 /*
2595 * This thread manage all clients request using the unix client socket for
2596 * communication.
2597 */
2598 static void *thread_manage_clients(void *data)
2599 {
2600 int sock = 0, ret;
2601 struct command_ctx *cmd_ctx = NULL;
2602 struct pollfd pollfd[2];
2603
2604 DBG("[thread] Manage client started");
2605
2606 ret = lttcomm_listen_unix_sock(client_sock);
2607 if (ret < 0) {
2608 goto error;
2609 }
2610
2611 /* First fd is always the quit pipe */
2612 pollfd[0].fd = thread_quit_pipe[0];
2613
2614 /* Apps socket */
2615 pollfd[1].fd = client_sock;
2616 pollfd[1].events = POLLIN;
2617
2618 /* Notify parent pid that we are ready
2619 * to accept command for client side.
2620 */
2621 if (opt_sig_parent) {
2622 kill(ppid, SIGCHLD);
2623 }
2624
2625 while (1) {
2626 DBG("Accepting client command ...");
2627
2628 /* Inifinite blocking call, waiting for transmission */
2629 ret = poll(pollfd, 2, -1);
2630 if (ret < 0) {
2631 perror("poll client thread");
2632 goto error;
2633 }
2634
2635 /* Thread quit pipe has been closed. Killing thread. */
2636 if (pollfd[0].revents == POLLNVAL) {
2637 goto error;
2638 } else if (pollfd[1].revents == POLLERR) {
2639 ERR("Client socket poll error");
2640 goto error;
2641 }
2642
2643 sock = lttcomm_accept_unix_sock(client_sock);
2644 if (sock < 0) {
2645 goto error;
2646 }
2647
2648 /* Allocate context command to process the client request */
2649 cmd_ctx = malloc(sizeof(struct command_ctx));
2650
2651 /* Allocate data buffer for reception */
2652 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2653 cmd_ctx->llm = NULL;
2654 cmd_ctx->session = NULL;
2655
2656 /*
2657 * Data is received from the lttng client. The struct
2658 * lttcomm_session_msg (lsm) contains the command and data request of
2659 * the client.
2660 */
2661 DBG("Receiving data from client ...");
2662 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2663 if (ret <= 0) {
2664 continue;
2665 }
2666
2667 // TODO: Validate cmd_ctx including sanity check for security purpose.
2668
2669 /*
2670 * This function dispatch the work to the kernel or userspace tracer
2671 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2672 * informations for the client. The command context struct contains
2673 * everything this function may needs.
2674 */
2675 ret = process_client_msg(cmd_ctx);
2676 if (ret < 0) {
2677 /* TODO: Inform client somehow of the fatal error. At this point,
2678 * ret < 0 means that a malloc failed (ENOMEM). */
2679 /* Error detected but still accept command */
2680 clean_command_ctx(&cmd_ctx);
2681 continue;
2682 }
2683
2684 DBG("Sending response (size: %d, retcode: %d)",
2685 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2686 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2687 if (ret < 0) {
2688 ERR("Failed to send data back to client");
2689 }
2690
2691 clean_command_ctx(&cmd_ctx);
2692
2693 /* End of transmission */
2694 close(sock);
2695 }
2696
2697 error:
2698 DBG("Client thread dying");
2699 if (client_sock) {
2700 close(client_sock);
2701 }
2702 if (sock) {
2703 close(sock);
2704 }
2705
2706 unlink(client_unix_sock_path);
2707
2708 clean_command_ctx(&cmd_ctx);
2709 return NULL;
2710 }
2711
2712
2713 /*
2714 * usage function on stderr
2715 */
2716 static void usage(void)
2717 {
2718 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2719 fprintf(stderr, " -h, --help Display this usage.\n");
2720 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2721 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2722 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2723 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2724 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2725 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2726 fprintf(stderr, " -V, --version Show version number.\n");
2727 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2728 fprintf(stderr, " -q, --quiet No output at all.\n");
2729 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2730 fprintf(stderr, " --verbose-kconsumerd Verbose mode for kconsumerd. Activate DBG() macro.\n");
2731 }
2732
2733 /*
2734 * daemon argument parsing
2735 */
2736 static int parse_args(int argc, char **argv)
2737 {
2738 int c;
2739
2740 static struct option long_options[] = {
2741 { "client-sock", 1, 0, 'c' },
2742 { "apps-sock", 1, 0, 'a' },
2743 { "kconsumerd-cmd-sock", 1, 0, 0 },
2744 { "kconsumerd-err-sock", 1, 0, 0 },
2745 { "daemonize", 0, 0, 'd' },
2746 { "sig-parent", 0, 0, 'S' },
2747 { "help", 0, 0, 'h' },
2748 { "group", 1, 0, 'g' },
2749 { "version", 0, 0, 'V' },
2750 { "quiet", 0, 0, 'q' },
2751 { "verbose", 0, 0, 'v' },
2752 { "verbose-kconsumerd", 0, 0, 'Z' },
2753 { NULL, 0, 0, 0 }
2754 };
2755
2756 while (1) {
2757 int option_index = 0;
2758 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:Z", long_options, &option_index);
2759 if (c == -1) {
2760 break;
2761 }
2762
2763 switch (c) {
2764 case 0:
2765 fprintf(stderr, "option %s", long_options[option_index].name);
2766 if (optarg) {
2767 fprintf(stderr, " with arg %s\n", optarg);
2768 }
2769 break;
2770 case 'c':
2771 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2772 break;
2773 case 'a':
2774 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2775 break;
2776 case 'd':
2777 opt_daemon = 1;
2778 break;
2779 case 'g':
2780 opt_tracing_group = strdup(optarg);
2781 break;
2782 case 'h':
2783 usage();
2784 exit(EXIT_FAILURE);
2785 case 'V':
2786 fprintf(stdout, "%s\n", VERSION);
2787 exit(EXIT_SUCCESS);
2788 case 'S':
2789 opt_sig_parent = 1;
2790 break;
2791 case 'E':
2792 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2793 break;
2794 case 'C':
2795 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2796 break;
2797 case 'q':
2798 opt_quiet = 1;
2799 break;
2800 case 'v':
2801 /* Verbose level can increase using multiple -v */
2802 opt_verbose += 1;
2803 break;
2804 case 'Z':
2805 opt_verbose_kconsumerd += 1;
2806 break;
2807 default:
2808 /* Unknown option or other error.
2809 * Error is printed by getopt, just return */
2810 return -1;
2811 }
2812 }
2813
2814 return 0;
2815 }
2816
2817 /*
2818 * Creates the two needed socket by the daemon.
2819 * apps_sock - The communication socket for all UST apps.
2820 * client_sock - The communication of the cli tool (lttng).
2821 */
2822 static int init_daemon_socket(void)
2823 {
2824 int ret = 0;
2825 mode_t old_umask;
2826
2827 old_umask = umask(0);
2828
2829 /* Create client tool unix socket */
2830 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2831 if (client_sock < 0) {
2832 ERR("Create unix sock failed: %s", client_unix_sock_path);
2833 ret = -1;
2834 goto end;
2835 }
2836
2837 /* File permission MUST be 660 */
2838 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2839 if (ret < 0) {
2840 ERR("Set file permissions failed: %s", client_unix_sock_path);
2841 perror("chmod");
2842 goto end;
2843 }
2844
2845 /* Create the application unix socket */
2846 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2847 if (apps_sock < 0) {
2848 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2849 ret = -1;
2850 goto end;
2851 }
2852
2853 /* File permission MUST be 666 */
2854 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2855 if (ret < 0) {
2856 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2857 perror("chmod");
2858 goto end;
2859 }
2860
2861 end:
2862 umask(old_umask);
2863 return ret;
2864 }
2865
2866 /*
2867 * Check if the global socket is available, and if a daemon is answering
2868 * at the other side. If yes, error is returned.
2869 */
2870 static int check_existing_daemon(void)
2871 {
2872 if (access(client_unix_sock_path, F_OK) < 0 &&
2873 access(apps_unix_sock_path, F_OK) < 0) {
2874 return 0;
2875 }
2876 /* Is there anybody out there ? */
2877 if (lttng_session_daemon_alive()) {
2878 return -EEXIST;
2879 } else {
2880 return 0;
2881 }
2882 }
2883
2884 /*
2885 * Set the tracing group gid onto the client socket.
2886 *
2887 * Race window between mkdir and chown is OK because we are going from more
2888 * permissive (root.root) to les permissive (root.tracing).
2889 */
2890 static int set_permissions(void)
2891 {
2892 int ret;
2893 gid_t gid;
2894
2895 gid = allowed_group();
2896 if (gid < 0) {
2897 if (is_root) {
2898 WARN("No tracing group detected");
2899 ret = 0;
2900 } else {
2901 ERR("Missing tracing group. Aborting execution.");
2902 ret = -1;
2903 }
2904 goto end;
2905 }
2906
2907 /* Set lttng run dir */
2908 ret = chown(LTTNG_RUNDIR, 0, gid);
2909 if (ret < 0) {
2910 ERR("Unable to set group on " LTTNG_RUNDIR);
2911 perror("chown");
2912 }
2913
2914 /* lttng client socket path */
2915 ret = chown(client_unix_sock_path, 0, gid);
2916 if (ret < 0) {
2917 ERR("Unable to set group on %s", client_unix_sock_path);
2918 perror("chown");
2919 }
2920
2921 /* kconsumerd error socket path */
2922 ret = chown(kconsumerd_err_unix_sock_path, 0, gid);
2923 if (ret < 0) {
2924 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2925 perror("chown");
2926 }
2927
2928 DBG("All permissions are set");
2929
2930 end:
2931 return ret;
2932 }
2933
2934 /*
2935 * Create the pipe used to wake up the kernel thread.
2936 */
2937 static int create_kernel_poll_pipe(void)
2938 {
2939 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2940 }
2941
2942 /*
2943 * Create the application command pipe to wake thread_manage_apps.
2944 */
2945 static int create_apps_cmd_pipe(void)
2946 {
2947 return pipe2(apps_cmd_pipe, O_CLOEXEC);
2948 }
2949
2950 /*
2951 * Create the lttng run directory needed for all global sockets and pipe.
2952 */
2953 static int create_lttng_rundir(void)
2954 {
2955 int ret;
2956
2957 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2958 if (ret < 0) {
2959 if (errno != EEXIST) {
2960 ERR("Unable to create " LTTNG_RUNDIR);
2961 goto error;
2962 } else {
2963 ret = 0;
2964 }
2965 }
2966
2967 error:
2968 return ret;
2969 }
2970
2971 /*
2972 * Setup sockets and directory needed by the kconsumerd communication with the
2973 * session daemon.
2974 */
2975 static int set_kconsumerd_sockets(void)
2976 {
2977 int ret;
2978
2979 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2980 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2981 }
2982
2983 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2984 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2985 }
2986
2987 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2988 if (ret < 0) {
2989 if (errno != EEXIST) {
2990 ERR("Failed to create " KCONSUMERD_PATH);
2991 goto error;
2992 }
2993 ret = 0;
2994 }
2995
2996 /* Create the kconsumerd error unix socket */
2997 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2998 if (kconsumerd_err_sock < 0) {
2999 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
3000 ret = -1;
3001 goto error;
3002 }
3003
3004 /* File permission MUST be 660 */
3005 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
3006 if (ret < 0) {
3007 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
3008 perror("chmod");
3009 goto error;
3010 }
3011
3012 error:
3013 return ret;
3014 }
3015
3016 /*
3017 * Signal handler for the daemon
3018 *
3019 * Simply stop all worker threads, leaving main() return gracefully
3020 * after joining all threads and calling cleanup().
3021 */
3022 static void sighandler(int sig)
3023 {
3024 switch (sig) {
3025 case SIGPIPE:
3026 DBG("SIGPIPE catched");
3027 return;
3028 case SIGINT:
3029 DBG("SIGINT catched");
3030 stop_threads();
3031 break;
3032 case SIGTERM:
3033 DBG("SIGTERM catched");
3034 stop_threads();
3035 break;
3036 default:
3037 break;
3038 }
3039 }
3040
3041 /*
3042 * Setup signal handler for :
3043 * SIGINT, SIGTERM, SIGPIPE
3044 */
3045 static int set_signal_handler(void)
3046 {
3047 int ret = 0;
3048 struct sigaction sa;
3049 sigset_t sigset;
3050
3051 if ((ret = sigemptyset(&sigset)) < 0) {
3052 perror("sigemptyset");
3053 return ret;
3054 }
3055
3056 sa.sa_handler = sighandler;
3057 sa.sa_mask = sigset;
3058 sa.sa_flags = 0;
3059 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
3060 perror("sigaction");
3061 return ret;
3062 }
3063
3064 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
3065 perror("sigaction");
3066 return ret;
3067 }
3068
3069 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
3070 perror("sigaction");
3071 return ret;
3072 }
3073
3074 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
3075
3076 return ret;
3077 }
3078
3079 /*
3080 * Set open files limit to unlimited. This daemon can open a large number of
3081 * file descriptors in order to consumer multiple kernel traces.
3082 */
3083 static void set_ulimit(void)
3084 {
3085 int ret;
3086 struct rlimit lim;
3087
3088 /* The kernel does not allowed an infinite limit for open files */
3089 lim.rlim_cur = 65535;
3090 lim.rlim_max = 65535;
3091
3092 ret = setrlimit(RLIMIT_NOFILE, &lim);
3093 if (ret < 0) {
3094 perror("failed to set open files limit");
3095 }
3096 }
3097
3098 /*
3099 * main
3100 */
3101 int main(int argc, char **argv)
3102 {
3103 int ret = 0;
3104 void *status;
3105 const char *home_path;
3106
3107 /* Create thread quit pipe */
3108 if ((ret = init_thread_quit_pipe()) < 0) {
3109 goto error;
3110 }
3111
3112 /* Parse arguments */
3113 progname = argv[0];
3114 if ((ret = parse_args(argc, argv) < 0)) {
3115 goto error;
3116 }
3117
3118 /* Daemonize */
3119 if (opt_daemon) {
3120 ret = daemon(0, 0);
3121 if (ret < 0) {
3122 perror("daemon");
3123 goto error;
3124 }
3125 }
3126
3127 /* Check if daemon is UID = 0 */
3128 is_root = !getuid();
3129
3130 if (is_root) {
3131 ret = create_lttng_rundir();
3132 if (ret < 0) {
3133 goto error;
3134 }
3135
3136 if (strlen(apps_unix_sock_path) == 0) {
3137 snprintf(apps_unix_sock_path, PATH_MAX,
3138 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
3139 }
3140
3141 if (strlen(client_unix_sock_path) == 0) {
3142 snprintf(client_unix_sock_path, PATH_MAX,
3143 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
3144 }
3145
3146 /* Set global SHM for ust */
3147 if (strlen(wait_shm_path) == 0) {
3148 snprintf(wait_shm_path, PATH_MAX,
3149 DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
3150 }
3151 } else {
3152 home_path = get_home_dir();
3153 if (home_path == NULL) {
3154 /* TODO: Add --socket PATH option */
3155 ERR("Can't get HOME directory for sockets creation.");
3156 ret = -EPERM;
3157 goto error;
3158 }
3159
3160 if (strlen(apps_unix_sock_path) == 0) {
3161 snprintf(apps_unix_sock_path, PATH_MAX,
3162 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
3163 }
3164
3165 /* Set the cli tool unix socket path */
3166 if (strlen(client_unix_sock_path) == 0) {
3167 snprintf(client_unix_sock_path, PATH_MAX,
3168 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
3169 }
3170
3171 /* Set global SHM for ust */
3172 if (strlen(wait_shm_path) == 0) {
3173 snprintf(wait_shm_path, PATH_MAX,
3174 DEFAULT_HOME_APPS_WAIT_SHM_PATH, geteuid());
3175 }
3176 }
3177
3178 DBG("Client socket path %s", client_unix_sock_path);
3179 DBG("Application socket path %s", apps_unix_sock_path);
3180
3181 /*
3182 * See if daemon already exist.
3183 */
3184 if ((ret = check_existing_daemon()) < 0) {
3185 ERR("Already running daemon.\n");
3186 /*
3187 * We do not goto exit because we must not cleanup()
3188 * because a daemon is already running.
3189 */
3190 goto error;
3191 }
3192
3193 /* After this point, we can safely call cleanup() so goto error is used */
3194
3195 /*
3196 * These actions must be executed as root. We do that *after* setting up
3197 * the sockets path because we MUST make the check for another daemon using
3198 * those paths *before* trying to set the kernel consumer sockets and init
3199 * kernel tracer.
3200 */
3201 if (is_root) {
3202 ret = set_kconsumerd_sockets();
3203 if (ret < 0) {
3204 goto exit;
3205 }
3206
3207 /* Setup kernel tracer */
3208 init_kernel_tracer();
3209
3210 /* Set ulimit for open files */
3211 set_ulimit();
3212 }
3213
3214 if ((ret = set_signal_handler()) < 0) {
3215 goto exit;
3216 }
3217
3218 /* Setup the needed unix socket */
3219 if ((ret = init_daemon_socket()) < 0) {
3220 goto exit;
3221 }
3222
3223 /* Set credentials to socket */
3224 if (is_root && ((ret = set_permissions()) < 0)) {
3225 goto exit;
3226 }
3227
3228 /* Get parent pid if -S, --sig-parent is specified. */
3229 if (opt_sig_parent) {
3230 ppid = getppid();
3231 }
3232
3233 /* Setup the kernel pipe for waking up the kernel thread */
3234 if ((ret = create_kernel_poll_pipe()) < 0) {
3235 goto exit;
3236 }
3237
3238 /* Setup the thread apps communication pipe. */
3239 if ((ret = create_apps_cmd_pipe()) < 0) {
3240 goto exit;
3241 }
3242
3243 /* Init UST command queue. */
3244 cds_wfq_init(&ust_cmd_queue.queue);
3245
3246 /*
3247 * Get session list pointer. This pointer MUST NOT be free().
3248 * This list is statically declared in session.c
3249 */
3250 session_list_ptr = get_session_list();
3251
3252 /* Create thread to manage the client socket */
3253 ret = pthread_create(&client_thread, NULL,
3254 thread_manage_clients, (void *) NULL);
3255 if (ret != 0) {
3256 perror("pthread_create clients");
3257 goto exit_client;
3258 }
3259
3260 /* Create thread to dispatch registration */
3261 ret = pthread_create(&dispatch_thread, NULL,
3262 thread_dispatch_ust_registration, (void *) NULL);
3263 if (ret != 0) {
3264 perror("pthread_create dispatch");
3265 goto exit_dispatch;
3266 }
3267
3268 /* Create thread to manage application registration. */
3269 ret = pthread_create(&reg_apps_thread, NULL,
3270 thread_registration_apps, (void *) NULL);
3271 if (ret != 0) {
3272 perror("pthread_create registration");
3273 goto exit_reg_apps;
3274 }
3275
3276 /* Create thread to manage application socket */
3277 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
3278 if (ret != 0) {
3279 perror("pthread_create apps");
3280 goto exit_apps;
3281 }
3282
3283 /* Create kernel thread to manage kernel event */
3284 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
3285 if (ret != 0) {
3286 perror("pthread_create kernel");
3287 goto exit_kernel;
3288 }
3289
3290 ret = pthread_join(kernel_thread, &status);
3291 if (ret != 0) {
3292 perror("pthread_join");
3293 goto error; /* join error, exit without cleanup */
3294 }
3295
3296 exit_kernel:
3297 ret = pthread_join(apps_thread, &status);
3298 if (ret != 0) {
3299 perror("pthread_join");
3300 goto error; /* join error, exit without cleanup */
3301 }
3302
3303 exit_apps:
3304 ret = pthread_join(reg_apps_thread, &status);
3305 if (ret != 0) {
3306 perror("pthread_join");
3307 goto error; /* join error, exit without cleanup */
3308 }
3309
3310 exit_reg_apps:
3311 ret = pthread_join(dispatch_thread, &status);
3312 if (ret != 0) {
3313 perror("pthread_join");
3314 goto error; /* join error, exit without cleanup */
3315 }
3316
3317 exit_dispatch:
3318 ret = pthread_join(client_thread, &status);
3319 if (ret != 0) {
3320 perror("pthread_join");
3321 goto error; /* join error, exit without cleanup */
3322 }
3323
3324 ret = join_kconsumerd_thread();
3325 if (ret != 0) {
3326 perror("join_kconsumerd");
3327