Fix tracing events data structure
[lttng-tools.git] / ltt-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple 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 <poll.h>
25 #include <pthread.h>
26 #include <semaphore.h>
27 #include <signal.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/ipc.h>
32 #include <sys/mount.h>
33 #include <sys/shm.h>
34 #include <sys/socket.h>
35 #include <sys/stat.h>
36 #include <sys/types.h>
37 #include <sys/time.h>
38 #include <sys/resource.h>
39 #include <unistd.h>
40
41 #include <urcu/list.h> /* URCU list library (-lurcu) */
42 #include <lttng/lttng.h>
43
44 #include "liblttsessiondcomm.h"
45 #include "ltt-sessiond.h"
46 #include "lttngerr.h"
47 #include "kernel-ctl.h"
48 #include "ust-ctl.h"
49 #include "session.h"
50 #include "traceable-app.h"
51 #include "lttng-kconsumerd.h"
52 #include "utils.h"
53
54 /*
55 * TODO:
56 * teardown: signal SIGTERM handler -> write into pipe. Threads waits
57 * with epoll on pipe and on other pipes/sockets for commands. Main
58 * simply waits on pthread join.
59 */
60
61 /* Const values */
62 const char default_home_dir[] = DEFAULT_HOME_DIR;
63 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
64 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
65 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
66
67 /* Variables */
68 int opt_verbose; /* Not static for lttngerr.h */
69 int opt_quiet; /* Not static for lttngerr.h */
70 const char *progname;
71 const char *opt_tracing_group;
72 static int opt_sig_parent;
73 static int opt_daemon;
74 static int is_root; /* Set to 1 if the daemon is running as root */
75 static pid_t ppid; /* Parent PID for --sig-parent option */
76 static pid_t kconsumerd_pid;
77 static struct pollfd *kernel_pollfd;
78
79 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
80 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
81 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
82 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
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 /* Pthread, Mutexes and Semaphores */
99 static pthread_t kconsumerd_thread;
100 static pthread_t apps_thread;
101 static pthread_t client_thread;
102 static pthread_t kernel_thread;
103 static sem_t kconsumerd_sem;
104
105 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
106
107 /*
108 * Pointer initialized before thread creation.
109 *
110 * This points to the tracing session list containing the session count and a
111 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
112 * MUST NOT be taken if you call a public function in session.c.
113 *
114 * The lock is nested inside the structure: session_list_ptr->lock.
115 */
116 static struct ltt_session_list *session_list_ptr;
117
118 /*
119 * Init quit pipe.
120 *
121 * Return -1 on error or 0 if all pipes are created.
122 */
123 static int init_thread_quit_pipe(void)
124 {
125 int ret;
126
127 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
128 if (ret < 0) {
129 perror("thread quit pipe");
130 goto error;
131 }
132
133 error:
134 return ret;
135 }
136
137 /*
138 * teardown_kernel_session
139 *
140 * Complete teardown of a kernel session. This free all data structure related
141 * to a kernel session and update counter.
142 */
143 static void teardown_kernel_session(struct ltt_session *session)
144 {
145 if (session->kernel_session != NULL) {
146 DBG("Tearing down kernel session");
147 trace_destroy_kernel_session(session->kernel_session);
148 /* Extra precaution */
149 session->kernel_session = NULL;
150 }
151 }
152
153 /*
154 * Cleanup the daemon
155 */
156 static void cleanup()
157 {
158 int ret;
159 char *cmd;
160 struct ltt_session *sess;
161
162 DBG("Cleaning up");
163
164 /* <fun> */
165 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
166 "Matthew, BEET driven development works!%c[%dm",
167 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
168 /* </fun> */
169
170 /* Stopping all threads */
171 DBG("Terminating all threads");
172 close(thread_quit_pipe[0]);
173 close(thread_quit_pipe[1]);
174
175 DBG("Removing %s directory", LTTNG_RUNDIR);
176 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
177 if (ret < 0) {
178 ERR("asprintf failed. Something is really wrong!");
179 }
180
181 /* Remove lttng run directory */
182 ret = system(cmd);
183 if (ret < 0) {
184 ERR("Unable to clean " LTTNG_RUNDIR);
185 }
186
187 DBG("Cleaning up all session");
188
189 /* Destroy session list mutex */
190 if (session_list_ptr != NULL) {
191 pthread_mutex_destroy(&session_list_ptr->lock);
192
193 /* Cleanup ALL session */
194 cds_list_for_each_entry(sess, &session_list_ptr->head, list) {
195 teardown_kernel_session(sess);
196 // TODO complete session cleanup (including UST)
197 }
198 }
199
200 pthread_mutex_destroy(&kconsumerd_pid_mutex);
201
202 DBG("Closing kernel fd");
203 close(kernel_tracer_fd);
204 }
205
206 /*
207 * send_unix_sock
208 *
209 * Send data on a unix socket using the liblttsessiondcomm API.
210 *
211 * Return lttcomm error code.
212 */
213 static int send_unix_sock(int sock, void *buf, size_t len)
214 {
215 /* Check valid length */
216 if (len <= 0) {
217 return -1;
218 }
219
220 return lttcomm_send_unix_sock(sock, buf, len);
221 }
222
223 /*
224 * clean_command_ctx
225 *
226 * Free memory of a command context structure.
227 */
228 static void clean_command_ctx(struct command_ctx **cmd_ctx)
229 {
230 DBG("Clean command context structure");
231 if (*cmd_ctx) {
232 if ((*cmd_ctx)->llm) {
233 free((*cmd_ctx)->llm);
234 }
235 if ((*cmd_ctx)->lsm) {
236 free((*cmd_ctx)->lsm);
237 }
238 free(*cmd_ctx);
239 *cmd_ctx = NULL;
240 }
241 }
242
243 /*
244 * send_kconsumerd_channel_fds
245 *
246 * Send all stream fds of kernel channel to the consumer.
247 */
248 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
249 {
250 int ret;
251 size_t nb_fd;
252 struct ltt_kernel_stream *stream;
253 struct lttcomm_kconsumerd_header lkh;
254 struct lttcomm_kconsumerd_msg lkm;
255
256 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
257
258 nb_fd = channel->stream_count;
259
260 /* Setup header */
261 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
262 lkh.cmd_type = ADD_STREAM;
263
264 DBG("Sending kconsumerd header");
265
266 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
267 if (ret < 0) {
268 perror("send kconsumerd header");
269 goto error;
270 }
271
272 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
273 if (stream->fd != 0) {
274 lkm.fd = stream->fd;
275 lkm.state = stream->state;
276 lkm.max_sb_size = channel->channel->attr.subbuf_size;
277 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
278
279 DBG("Sending fd %d to kconsumerd", lkm.fd);
280
281 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
282 if (ret < 0) {
283 perror("send kconsumerd fd");
284 goto error;
285 }
286 }
287 }
288
289 DBG("Kconsumerd channel fds sent");
290
291 return 0;
292
293 error:
294 return ret;
295 }
296
297 /*
298 * send_kconsumerd_fds
299 *
300 * Send all stream fds of the kernel session to the consumer.
301 */
302 static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
303 {
304 int ret;
305 struct ltt_kernel_channel *chan;
306 struct lttcomm_kconsumerd_header lkh;
307 struct lttcomm_kconsumerd_msg lkm;
308
309 /* Setup header */
310 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
311 lkh.cmd_type = ADD_STREAM;
312
313 DBG("Sending kconsumerd header for metadata");
314
315 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
316 if (ret < 0) {
317 perror("send kconsumerd header");
318 goto error;
319 }
320
321 DBG("Sending metadata stream fd");
322
323 if (session->metadata_stream_fd != 0) {
324 /* Send metadata stream fd first */
325 lkm.fd = session->metadata_stream_fd;
326 lkm.state = ACTIVE_FD;
327 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
328 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
329
330 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
331 if (ret < 0) {
332 perror("send kconsumerd fd");
333 goto error;
334 }
335 }
336
337 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
338 ret = send_kconsumerd_channel_fds(sock, chan);
339 if (ret < 0) {
340 goto error;
341 }
342 }
343
344 DBG("Kconsumerd fds (metadata and channel streams) sent");
345
346 return 0;
347
348 error:
349 return ret;
350 }
351
352 #ifdef DISABLED
353 /*
354 * ust_connect_app
355 *
356 * Return a socket connected to the libust communication socket
357 * of the application identified by the pid.
358 *
359 * If the pid is not found in the traceable list,
360 * return -1 to indicate error.
361 */
362 static int ust_connect_app(pid_t pid)
363 {
364 int sock;
365 struct ltt_traceable_app *lta;
366
367 DBG("Connect to application pid %d", pid);
368
369 lta = find_app_by_pid(pid);
370 if (lta == NULL) {
371 /* App not found */
372 DBG("Application pid %d not found", pid);
373 return -1;
374 }
375
376 sock = ustctl_connect_pid(lta->pid);
377 if (sock < 0) {
378 ERR("Fail connecting to the PID %d", pid);
379 }
380
381 return sock;
382 }
383 #endif /* DISABLED */
384
385 /*
386 * notify_apps
387 *
388 * Notify apps by writing 42 to a named pipe using name.
389 * Every applications waiting for a ltt-sessiond will be notified
390 * and re-register automatically to the session daemon.
391 *
392 * Return open or write error value.
393 */
394 static int notify_apps(const char *name)
395 {
396 int fd;
397 int ret = -1;
398
399 DBG("Notify the global application pipe");
400
401 /* Try opening the global pipe */
402 fd = open(name, O_WRONLY);
403 if (fd < 0) {
404 goto error;
405 }
406
407 /* Notify by writing on the pipe */
408 ret = write(fd, "42", 2);
409 if (ret < 0) {
410 perror("write");
411 }
412
413 error:
414 return ret;
415 }
416
417 /*
418 * setup_lttng_msg
419 *
420 * Setup the outgoing data buffer for the response (llm) by allocating the
421 * right amount of memory and copying the original information from the lsm
422 * structure.
423 *
424 * Return total size of the buffer pointed by buf.
425 */
426 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
427 {
428 int ret, buf_size;
429
430 buf_size = size;
431
432 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
433 if (cmd_ctx->llm == NULL) {
434 perror("malloc");
435 ret = -ENOMEM;
436 goto error;
437 }
438
439 /* Copy common data */
440 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
441 cmd_ctx->llm->pid = cmd_ctx->lsm->pid;
442
443 cmd_ctx->llm->data_size = size;
444 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
445
446 return buf_size;
447
448 error:
449 return ret;
450 }
451
452 /*
453 * update_kernel_pollfd
454 *
455 * Update the kernel pollfd set of all channel fd available over
456 * all tracing session. Add the wakeup pipe at the end of the set.
457 */
458 static int update_kernel_pollfd(void)
459 {
460 int i = 0;
461 /*
462 * The wakup pipe and the quit pipe are needed so the number of fds starts
463 * at 2 for those pipes.
464 */
465 unsigned int nb_fd = 2;
466 struct ltt_session *session;
467 struct ltt_kernel_channel *channel;
468
469 DBG("Updating kernel_pollfd");
470
471 /* Get the number of channel of all kernel session */
472 lock_session_list();
473 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
474 lock_session(session);
475 if (session->kernel_session == NULL) {
476 unlock_session(session);
477 continue;
478 }
479 nb_fd += session->kernel_session->channel_count;
480 unlock_session(session);
481 }
482
483 DBG("Resizing kernel_pollfd to size %d", nb_fd);
484
485 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
486 if (kernel_pollfd == NULL) {
487 perror("malloc kernel_pollfd");
488 goto error;
489 }
490
491 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
492 lock_session(session);
493 if (session->kernel_session == NULL) {
494 unlock_session(session);
495 continue;
496 }
497 if (i >= nb_fd) {
498 ERR("To much channel for kernel_pollfd size");
499 unlock_session(session);
500 break;
501 }
502 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
503 kernel_pollfd[i].fd = channel->fd;
504 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
505 i++;
506 }
507 unlock_session(session);
508 }
509 unlock_session_list();
510
511 /* Adding wake up pipe */
512 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
513 kernel_pollfd[nb_fd - 2].events = POLLIN;
514
515 /* Adding the quit pipe */
516 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
517
518 return nb_fd;
519
520 error:
521 unlock_session_list();
522 return -1;
523 }
524
525 /*
526 * update_kernel_stream
527 *
528 * Find the channel fd from 'fd' over all tracing session. When found, check
529 * for new channel stream and send those stream fds to the kernel consumer.
530 *
531 * Useful for CPU hotplug feature.
532 */
533 static int update_kernel_stream(int fd)
534 {
535 int ret = 0;
536 struct ltt_session *session;
537 struct ltt_kernel_channel *channel;
538
539 DBG("Updating kernel streams for channel fd %d", fd);
540
541 lock_session_list();
542 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
543 lock_session(session);
544 if (session->kernel_session == NULL) {
545 unlock_session(session);
546 continue;
547 }
548 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
549 if (channel->fd == fd) {
550 DBG("Channel found, updating kernel streams");
551 ret = kernel_open_channel_stream(channel);
552 if (ret < 0) {
553 goto end;
554 }
555 /*
556 * Have we already sent fds to the consumer? If yes, it means that
557 * tracing is started so it is safe to send our updated stream fds.
558 */
559 if (session->kernel_session->kconsumer_fds_sent == 1) {
560 ret = send_kconsumerd_channel_fds(kconsumerd_cmd_sock, channel);
561 if (ret < 0) {
562 goto end;
563 }
564 }
565 goto end;
566 }
567 }
568 unlock_session(session);
569 }
570
571 end:
572 unlock_session_list();
573 if (session) {
574 unlock_session(session);
575 }
576 return ret;
577 }
578
579 /*
580 * thread_manage_kernel
581 *
582 * This thread manage event coming from the kernel.
583 *
584 * Features supported in this thread:
585 * -) CPU Hotplug
586 */
587 static void *thread_manage_kernel(void *data)
588 {
589 int ret, i, nb_fd = 0;
590 char tmp;
591 int update_poll_flag = 1;
592
593 DBG("Thread manage kernel started");
594
595 while (1) {
596 if (update_poll_flag == 1) {
597 nb_fd = update_kernel_pollfd();
598 if (nb_fd < 0) {
599 goto error;
600 }
601 update_poll_flag = 0;
602 }
603
604 DBG("Polling on %d fds", nb_fd);
605
606 /* Poll infinite value of time */
607 ret = poll(kernel_pollfd, nb_fd, -1);
608 if (ret < 0) {
609 perror("poll kernel thread");
610 goto error;
611 } else if (ret == 0) {
612 /* Should not happen since timeout is infinite */
613 continue;
614 }
615
616 /* Thread quit pipe has been closed. Killing thread. */
617 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
618 goto error;
619 }
620
621 DBG("Kernel poll event triggered");
622
623 /*
624 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
625 * must be updated.
626 */
627 switch (kernel_pollfd[nb_fd - 2].revents) {
628 case POLLIN:
629 ret = read(kernel_poll_pipe[0], &tmp, 1);
630 update_poll_flag = 1;
631 continue;
632 case POLLERR:
633 goto error;
634 default:
635 break;
636 }
637
638 for (i = 0; i < nb_fd; i++) {
639 switch (kernel_pollfd[i].revents) {
640 /*
641 * New CPU detected by the kernel. Adding kernel stream to kernel
642 * session and updating the kernel consumer
643 */
644 case POLLIN | POLLRDNORM:
645 ret = update_kernel_stream(kernel_pollfd[i].fd);
646 if (ret < 0) {
647 continue;
648 }
649 break;
650 }
651 }
652 }
653
654 error:
655 DBG("Kernel thread dying");
656 if (kernel_pollfd) {
657 free(kernel_pollfd);
658 }
659
660 close(kernel_poll_pipe[0]);
661 close(kernel_poll_pipe[1]);
662 return NULL;
663 }
664
665 /*
666 * thread_manage_kconsumerd
667 *
668 * This thread manage the kconsumerd error sent
669 * back to the session daemon.
670 */
671 static void *thread_manage_kconsumerd(void *data)
672 {
673 int sock = 0, ret;
674 enum lttcomm_return_code code;
675 struct pollfd pollfd[2];
676
677 DBG("[thread] Manage kconsumerd started");
678
679 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
680 if (ret < 0) {
681 goto error;
682 }
683
684 /* First fd is always the quit pipe */
685 pollfd[0].fd = thread_quit_pipe[0];
686
687 /* Apps socket */
688 pollfd[1].fd = kconsumerd_err_sock;
689 pollfd[1].events = POLLIN;
690
691 /* Inifinite blocking call, waiting for transmission */
692 ret = poll(pollfd, 2, -1);
693 if (ret < 0) {
694 perror("poll kconsumerd thread");
695 goto error;
696 }
697
698 /* Thread quit pipe has been closed. Killing thread. */
699 if (pollfd[0].revents == POLLNVAL) {
700 goto error;
701 } else if (pollfd[1].revents == POLLERR) {
702 ERR("Kconsumerd err socket poll error");
703 goto error;
704 }
705
706 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
707 if (sock < 0) {
708 goto error;
709 }
710
711 /* Getting status code from kconsumerd */
712 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
713 if (ret <= 0) {
714 goto error;
715 }
716
717 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
718 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
719 if (kconsumerd_cmd_sock < 0) {
720 sem_post(&kconsumerd_sem);
721 perror("kconsumerd connect");
722 goto error;
723 }
724 /* Signal condition to tell that the kconsumerd is ready */
725 sem_post(&kconsumerd_sem);
726 DBG("Kconsumerd command socket ready");
727 } else {
728 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
729 lttcomm_get_readable_code(-code));
730 goto error;
731 }
732
733 /* Wait for any kconsumerd error */
734 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
735 if (ret <= 0) {
736 ERR("Kconsumerd closed the command socket");
737 goto error;
738 }
739
740 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
741
742 error:
743 DBG("Kconsumerd thread dying");
744 if (kconsumerd_err_sock) {
745 close(kconsumerd_err_sock);
746 }
747 if (kconsumerd_cmd_sock) {
748 close(kconsumerd_cmd_sock);
749 }
750 if (sock) {
751 close(sock);
752 }
753
754 unlink(kconsumerd_err_unix_sock_path);
755 unlink(kconsumerd_cmd_unix_sock_path);
756
757 kconsumerd_pid = 0;
758 return NULL;
759 }
760
761 /*
762 * thread_manage_apps
763 *
764 * This thread manage the application socket communication
765 */
766 static void *thread_manage_apps(void *data)
767 {
768 int sock = 0, ret;
769 struct pollfd pollfd[2];
770
771 /* TODO: Something more elegant is needed but fine for now */
772 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
773 * for 32-bit vs 64-bit compat processes. */
774 /* replicate in ust with version number */
775 struct {
776 int reg; /* 1:register, 0:unregister */
777 pid_t pid;
778 uid_t uid;
779 } reg_msg;
780
781 DBG("[thread] Manage apps started");
782
783 ret = lttcomm_listen_unix_sock(apps_sock);
784 if (ret < 0) {
785 goto error;
786 }
787
788 /* First fd is always the quit pipe */
789 pollfd[0].fd = thread_quit_pipe[0];
790
791 /* Apps socket */
792 pollfd[1].fd = apps_sock;
793 pollfd[1].events = POLLIN;
794
795 /* Notify all applications to register */
796 notify_apps(default_global_apps_pipe);
797
798 while (1) {
799 DBG("Accepting application registration");
800
801 /* Inifinite blocking call, waiting for transmission */
802 ret = poll(pollfd, 2, -1);
803 if (ret < 0) {
804 perror("poll apps thread");
805 goto error;
806 }
807
808 /* Thread quit pipe has been closed. Killing thread. */
809 if (pollfd[0].revents == POLLNVAL) {
810 goto error;
811 } else if (pollfd[1].revents == POLLERR) {
812 ERR("Apps socket poll error");
813 goto error;
814 }
815
816 sock = lttcomm_accept_unix_sock(apps_sock);
817 if (sock < 0) {
818 goto error;
819 }
820
821 /*
822 * Basic recv here to handle the very simple data
823 * that the libust send to register (reg_msg).
824 */
825 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
826 if (ret < 0) {
827 perror("recv");
828 continue;
829 }
830
831 /* Add application to the global traceable list */
832 if (reg_msg.reg == 1) {
833 /* Registering */
834 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
835 if (ret < 0) {
836 /* register_traceable_app only return an error with
837 * ENOMEM. At this point, we better stop everything.
838 */
839 goto error;
840 }
841 } else {
842 /* Unregistering */
843 unregister_traceable_app(reg_msg.pid);
844 }
845 }
846
847 error:
848 DBG("Apps thread dying");
849 if (apps_sock) {
850 close(apps_sock);
851 }
852 if (sock) {
853 close(sock);
854 }
855
856 unlink(apps_unix_sock_path);
857 return NULL;
858 }
859
860 /*
861 * spawn_kconsumerd_thread
862 *
863 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
864 * exec or it will fails.
865 */
866 static int spawn_kconsumerd_thread(void)
867 {
868 int ret;
869
870 /* Setup semaphore */
871 sem_init(&kconsumerd_sem, 0, 0);
872
873 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
874 if (ret != 0) {
875 perror("pthread_create kconsumerd");
876 goto error;
877 }
878
879 /* Wait for the kconsumerd thread to be ready */
880 sem_wait(&kconsumerd_sem);
881
882 if (kconsumerd_pid == 0) {
883 ERR("Kconsumerd did not start");
884 goto error;
885 }
886
887 return 0;
888
889 error:
890 ret = LTTCOMM_KERN_CONSUMER_FAIL;
891 return ret;
892 }
893
894 /*
895 * spawn_kconsumerd
896 *
897 * Fork and exec a kernel consumer daemon (kconsumerd).
898 *
899 * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel
900 * file descriptor using the libkernelctl or kernel-ctl functions. So, a
901 * kernel consumer MUST only be spawned before creating a kernel session.
902 *
903 * Return pid if successful else -1.
904 */
905 static pid_t spawn_kconsumerd(void)
906 {
907 int ret;
908 pid_t pid;
909
910 DBG("Spawning kconsumerd");
911
912 pid = fork();
913 if (pid == 0) {
914 /*
915 * Exec kconsumerd.
916 */
917 execlp("ltt-kconsumerd", "ltt-kconsumerd", "--verbose", NULL);
918 if (errno != 0) {
919 perror("kernel start consumer exec");
920 }
921 exit(EXIT_FAILURE);
922 } else if (pid > 0) {
923 ret = pid;
924 goto error;
925 } else {
926 perror("kernel start consumer fork");
927 ret = -errno;
928 goto error;
929 }
930
931 error:
932 return ret;
933 }
934
935 /*
936 * start_kconsumerd
937 *
938 * Spawn the kconsumerd daemon and session daemon thread.
939 */
940 static int start_kconsumerd(void)
941 {
942 int ret;
943
944 pthread_mutex_lock(&kconsumerd_pid_mutex);
945 if (kconsumerd_pid != 0) {
946 pthread_mutex_unlock(&kconsumerd_pid_mutex);
947 goto end;
948 }
949
950 ret = spawn_kconsumerd();
951 if (ret < 0) {
952 ERR("Spawning kconsumerd failed");
953 ret = LTTCOMM_KERN_CONSUMER_FAIL;
954 pthread_mutex_unlock(&kconsumerd_pid_mutex);
955 goto error;
956 }
957
958 /* Setting up the global kconsumerd_pid */
959 kconsumerd_pid = ret;
960 pthread_mutex_unlock(&kconsumerd_pid_mutex);
961
962 DBG("Kconsumerd pid %d", ret);
963
964 DBG("Spawning kconsumerd thread");
965 ret = spawn_kconsumerd_thread();
966 if (ret < 0) {
967 ERR("Fatal error spawning kconsumerd thread");
968 goto error;
969 }
970
971 end:
972 return 0;
973
974 error:
975 return ret;
976 }
977
978 /*
979 * modprobe_kernel_modules
980 */
981 static int modprobe_kernel_modules(void)
982 {
983 int ret = 0, i = 0;
984 char modprobe[256];
985
986 while (kernel_modules_list[i] != NULL) {
987 ret = snprintf(modprobe, sizeof(modprobe), "/sbin/modprobe %s",
988 kernel_modules_list[i]);
989 if (ret < 0) {
990 perror("snprintf modprobe");
991 goto error;
992 }
993 ret = system(modprobe);
994 if (ret < 0) {
995 ERR("Unable to load module %s", kernel_modules_list[i]);
996 }
997 DBG("Modprobe successfully %s", kernel_modules_list[i]);
998 i++;
999 }
1000
1001 error:
1002 return ret;
1003 }
1004
1005 /*
1006 * mount_debugfs
1007 */
1008 static int mount_debugfs(char *path)
1009 {
1010 int ret;
1011 char *type = "debugfs";
1012
1013 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG);
1014 if (ret < 0) {
1015 goto error;
1016 }
1017
1018 ret = mount(type, path, type, 0, NULL);
1019 if (ret < 0) {
1020 perror("mount debugfs");
1021 goto error;
1022 }
1023
1024 DBG("Mounted debugfs successfully at %s", path);
1025
1026 error:
1027 return ret;
1028 }
1029
1030 /*
1031 * init_kernel_tracer
1032 *
1033 * Setup necessary data for kernel tracer action.
1034 */
1035 static void init_kernel_tracer(void)
1036 {
1037 int ret;
1038 char *proc_mounts = "/proc/mounts";
1039 char line[256];
1040 char *debugfs_path = NULL, *lttng_path;
1041 FILE *fp;
1042
1043 /* Detect debugfs */
1044 fp = fopen(proc_mounts, "r");
1045 if (fp == NULL) {
1046 ERR("Unable to probe %s", proc_mounts);
1047 goto error;
1048 }
1049
1050 while (fgets(line, sizeof(line), fp) != NULL) {
1051 if (strstr(line, "debugfs") != NULL) {
1052 /* Remove first string */
1053 strtok(line, " ");
1054 /* Dup string here so we can reuse line later on */
1055 debugfs_path = strdup(strtok(NULL, " "));
1056 DBG("Got debugfs path : %s", debugfs_path);
1057 break;
1058 }
1059 }
1060
1061 fclose(fp);
1062
1063 /* Mount debugfs if needded */
1064 if (debugfs_path == NULL) {
1065 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1066 if (ret < 0) {
1067 perror("asprintf debugfs path");
1068 goto error;
1069 }
1070 ret = mount_debugfs(debugfs_path);
1071 if (ret < 0) {
1072 goto error;
1073 }
1074 }
1075
1076 /* Modprobe lttng kernel modules */
1077 ret = modprobe_kernel_modules();
1078 if (ret < 0) {
1079 goto error;
1080 }
1081
1082 /* Setup lttng kernel path */
1083 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1084 if (ret < 0) {
1085 perror("asprintf lttng path");
1086 goto error;
1087 }
1088
1089 /* Open debugfs lttng */
1090 kernel_tracer_fd = open(lttng_path, O_RDWR);
1091 if (kernel_tracer_fd < 0) {
1092 DBG("Failed to open %s", lttng_path);
1093 goto error;
1094 }
1095
1096 free(lttng_path);
1097 free(debugfs_path);
1098 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1099 return;
1100
1101 error:
1102 if (lttng_path) {
1103 free(lttng_path);
1104 }
1105 if (debugfs_path) {
1106 free(debugfs_path);
1107 }
1108 WARN("No kernel tracer available");
1109 kernel_tracer_fd = 0;
1110 return;
1111 }
1112
1113 /*
1114 * start_kernel_trace
1115 *
1116 * Start tracing by creating trace directory and sending FDs to the kernel
1117 * consumer.
1118 */
1119 static int start_kernel_trace(struct ltt_kernel_session *session)
1120 {
1121 int ret;
1122
1123 if (session->kconsumer_fds_sent == 0) {
1124 ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
1125 if (ret < 0) {
1126 ERR("Send kconsumerd fds failed");
1127 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1128 goto error;
1129 }
1130
1131 session->kconsumer_fds_sent = 1;
1132 }
1133
1134 error:
1135 return ret;
1136 }
1137
1138 /*
1139 * Notify kernel thread to update it's pollfd.
1140 */
1141 static int notify_kernel_pollfd(void)
1142 {
1143 int ret;
1144
1145 /* Inform kernel thread of the new kernel channel */
1146 ret = write(kernel_poll_pipe[1], "!", 1);
1147 if (ret < 0) {
1148 perror("write kernel poll pipe");
1149 }
1150
1151 return ret;
1152 }
1153
1154 /*
1155 * init_default_channel
1156 *
1157 * Allocate a channel structure and fill it.
1158 */
1159 static struct lttng_channel *init_default_channel(void)
1160 {
1161 struct lttng_channel *chan;
1162
1163 chan = malloc(sizeof(struct lttng_channel));
1164 if (chan == NULL) {
1165 perror("init channel malloc");
1166 goto error;
1167 }
1168
1169 if (snprintf(chan->name, NAME_MAX, DEFAULT_CHANNEL_NAME) < 0) {
1170 perror("snprintf defautl channel name");
1171 return NULL;
1172 }
1173
1174 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1175 chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
1176 chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
1177 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1178 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1179 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1180
1181 error:
1182 return chan;
1183 }
1184
1185 /*
1186 * create_kernel_session
1187 *
1188 * Create a kernel tracer session then create the default channel.
1189 */
1190 static int create_kernel_session(struct ltt_session *session)
1191 {
1192 int ret;
1193 struct lttng_channel *chan;
1194
1195 DBG("Creating kernel session");
1196
1197 ret = kernel_create_session(session, kernel_tracer_fd);
1198 if (ret < 0) {
1199 ret = LTTCOMM_KERN_SESS_FAIL;
1200 goto error;
1201 }
1202
1203 chan = init_default_channel();
1204 if (chan == NULL) {
1205 ret = LTTCOMM_FATAL;
1206 goto error;
1207 }
1208
1209 ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG );
1210 if (ret < 0) {
1211 if (ret != EEXIST) {
1212 ERR("Trace directory creation error");
1213 goto error;
1214 }
1215 }
1216
1217 DBG("Creating default kernel channel %s", DEFAULT_CHANNEL_NAME);
1218
1219 ret = kernel_create_channel(session->kernel_session, chan, session->path);
1220 if (ret < 0) {
1221 ret = LTTCOMM_KERN_CHAN_FAIL;
1222 goto error;
1223 }
1224
1225 ret = notify_kernel_pollfd();
1226
1227 error:
1228 return ret;
1229 }
1230
1231 /*
1232 * Using the session list, filled a lttng_session array to send back to the
1233 * client for session listing.
1234 *
1235 * The session list lock MUST be acquired before calling this function. Use
1236 * lock_session_list() and unlock_session_list().
1237 */
1238 static void list_lttng_sessions(struct lttng_session *sessions)
1239 {
1240 int i = 0;
1241 struct ltt_session *session;
1242
1243 DBG("Getting all available session");
1244 /*
1245 * Iterate over session list and append data after the control struct in
1246 * the buffer.
1247 */
1248 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1249 strncpy(sessions[i].path, session->path, PATH_MAX);
1250 strncpy(sessions[i].name, session->name, NAME_MAX);
1251 i++;
1252 }
1253 }
1254
1255 /*
1256 * process_client_msg
1257 *
1258 * Process the command requested by the lttng client within the command
1259 * context structure. This function make sure that the return structure (llm)
1260 * is set and ready for transmission before returning.
1261 *
1262 * Return any error encountered or 0 for success.
1263 */
1264 static int process_client_msg(struct command_ctx *cmd_ctx)
1265 {
1266 int ret;
1267
1268 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1269
1270 /* Listing commands don't need a session */
1271 switch (cmd_ctx->lsm->cmd_type) {
1272 case LTTNG_CREATE_SESSION:
1273 case LTTNG_LIST_SESSIONS:
1274 case LTTNG_LIST_EVENTS:
1275 case LTTNG_KERNEL_LIST_EVENTS:
1276 case LTTNG_LIST_TRACEABLE_APPS:
1277 break;
1278 default:
1279 DBG("Getting session %s by name", cmd_ctx->lsm->session_name);
1280 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name);
1281 if (cmd_ctx->session == NULL) {
1282 /* If session name not found */
1283 if (cmd_ctx->lsm->session_name != NULL) {
1284 ret = LTTCOMM_SESS_NOT_FOUND;
1285 } else { /* If no session name specified */
1286 ret = LTTCOMM_SELECT_SESS;
1287 }
1288 goto error;
1289 } else {
1290 /* Acquire lock for the session */
1291 lock_session(cmd_ctx->session);
1292 }
1293 break;
1294 }
1295
1296 /*
1297 * Check kernel command for kernel session.
1298 */
1299 switch (cmd_ctx->lsm->cmd_type) {
1300 case LTTNG_KERNEL_ADD_CONTEXT:
1301 case LTTNG_KERNEL_CREATE_CHANNEL:
1302 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1303 case LTTNG_KERNEL_DISABLE_CHANNEL:
1304 case LTTNG_KERNEL_DISABLE_EVENT:
1305 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1306 case LTTNG_KERNEL_ENABLE_CHANNEL:
1307 case LTTNG_KERNEL_ENABLE_EVENT:
1308 case LTTNG_KERNEL_LIST_EVENTS:
1309 /* Kernel tracer check */
1310 if (kernel_tracer_fd == 0) {
1311 init_kernel_tracer();
1312 if (kernel_tracer_fd == 0) {
1313 ret = LTTCOMM_KERN_NA;
1314 goto error;
1315 }
1316 }
1317
1318 /* Need a session for kernel command */
1319 if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS &&
1320 cmd_ctx->session->kernel_session == NULL) {
1321
1322 ret = create_kernel_session(cmd_ctx->session);
1323 if (ret < 0) {
1324 ret = LTTCOMM_KERN_SESS_FAIL;
1325 goto error;
1326 }
1327
1328 /* Start the kernel consumer daemon */
1329 if (kconsumerd_pid == 0) {
1330 ret = start_kconsumerd();
1331 if (ret < 0) {
1332 goto error;
1333 }
1334 }
1335 }
1336 }
1337
1338 #ifdef DISABLED
1339 /* Connect to ust apps if available pid */
1340 if (cmd_ctx->lsm->pid > 0) {
1341 /* Connect to app using ustctl API */
1342 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
1343 if (cmd_ctx->ust_sock < 0) {
1344 ret = LTTCOMM_NO_TRACEABLE;
1345 goto error;
1346 }
1347 }
1348 #endif /* DISABLED */
1349
1350 /* Process by command type */
1351 switch (cmd_ctx->lsm->cmd_type) {
1352 case LTTNG_KERNEL_ADD_CONTEXT:
1353 {
1354 int found = 0, no_event = 0;
1355 struct ltt_kernel_channel *chan;
1356 struct ltt_kernel_event *event;
1357
1358 /* Setup lttng message with no payload */
1359 ret = setup_lttng_msg(cmd_ctx, 0);
1360 if (ret < 0) {
1361 goto setup_error;
1362 }
1363
1364 /* Check if event name is given */
1365 if (strlen(cmd_ctx->lsm->u.context.event_name) == 0) {
1366 no_event = 1;
1367 }
1368
1369 if (strlen(cmd_ctx->lsm->u.context.channel_name) == 0) {
1370 /* Go over all channels */
1371 DBG("Adding context to all channels");
1372 cds_list_for_each_entry(chan,
1373 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1374 if (no_event) {
1375 ret = kernel_add_channel_context(chan,
1376 &cmd_ctx->lsm->u.context.ctx);
1377 if (ret < 0) {
1378 continue;
1379 }
1380 } else {
1381 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1382 if (event != NULL) {
1383 ret = kernel_add_event_context(event,
1384 &cmd_ctx->lsm->u.context.ctx);
1385 if (ret < 0) {
1386 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1387 goto error;
1388 }
1389 found = 1;
1390 break;
1391 }
1392 }
1393 }
1394 } else {
1395 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.context.channel_name,
1396 cmd_ctx->session->kernel_session);
1397 if (chan == NULL) {
1398 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1399 goto error;
1400 }
1401
1402 if (no_event) {
1403 ret = kernel_add_channel_context(chan,
1404 &cmd_ctx->lsm->u.context.ctx);
1405 if (ret < 0) {
1406 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1407 goto error;
1408 }
1409 } else {
1410 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1411 if (event != NULL) {
1412 ret = kernel_add_event_context(event,
1413 &cmd_ctx->lsm->u.context.ctx);
1414 if (ret < 0) {
1415 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1416 goto error;
1417 }
1418 }
1419 }
1420 }
1421
1422 if (!found && !no_event) {
1423 ret = LTTCOMM_NO_EVENT;
1424 goto error;
1425 }
1426
1427 ret = LTTCOMM_OK;
1428 break;
1429 }
1430 case LTTNG_KERNEL_CREATE_CHANNEL:
1431 {
1432 /* Setup lttng message with no payload */
1433 ret = setup_lttng_msg(cmd_ctx, 0);
1434 if (ret < 0) {
1435 goto setup_error;
1436 }
1437
1438 /* Kernel tracer */
1439 DBG("Creating kernel channel");
1440
1441 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1442 &cmd_ctx->lsm->u.channel.chan, cmd_ctx->session->path);
1443 if (ret < 0) {
1444 ret = LTTCOMM_KERN_CHAN_FAIL;
1445 goto error;
1446 }
1447
1448 ret = notify_kernel_pollfd();
1449 if (ret < 0) {
1450 ret = LTTCOMM_FATAL;
1451 goto error;
1452 }
1453
1454 ret = LTTCOMM_OK;
1455 break;
1456 }
1457 case LTTNG_KERNEL_DISABLE_CHANNEL:
1458 {
1459 struct ltt_kernel_channel *chan;
1460
1461 /* Setup lttng message with no payload */
1462 ret = setup_lttng_msg(cmd_ctx, 0);
1463 if (ret < 0) {
1464 goto setup_error;
1465 }
1466
1467 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1468 cmd_ctx->session->kernel_session);
1469 if (chan == NULL) {
1470 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1471 goto error;
1472 } else if (chan->enabled == 1) {
1473 ret = kernel_disable_channel(chan);
1474 if (ret < 0) {
1475 if (ret != EEXIST) {
1476 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1477 }
1478 goto error;
1479 }
1480 }
1481
1482 kernel_wait_quiescent(kernel_tracer_fd);
1483 ret = LTTCOMM_OK;
1484 break;
1485 }
1486 case LTTNG_KERNEL_DISABLE_EVENT:
1487 {
1488 struct ltt_kernel_channel *chan;
1489 struct ltt_kernel_event *ev;
1490
1491 /* Setup lttng message with no payload */
1492 ret = setup_lttng_msg(cmd_ctx, 0);
1493 if (ret < 0) {
1494 goto setup_error;
1495 }
1496
1497 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1498 cmd_ctx->session->kernel_session);
1499 if (chan == NULL) {
1500 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1501 goto error;
1502 }
1503
1504 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, chan);
1505 if (ev != NULL) {
1506 DBG("Disabling kernel event %s for channel %s.",
1507 cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name);
1508 ret = kernel_disable_event(ev);
1509 if (ret < 0) {
1510 ret = LTTCOMM_KERN_ENABLE_FAIL;
1511 goto error;
1512 }
1513 }
1514
1515 kernel_wait_quiescent(kernel_tracer_fd);
1516 ret = LTTCOMM_OK;
1517 break;
1518 }
1519 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1520 {
1521 struct ltt_kernel_channel *chan;
1522 struct ltt_kernel_event *ev;
1523
1524 /* Setup lttng message with no payload */
1525 ret = setup_lttng_msg(cmd_ctx, 0);
1526 if (ret < 0) {
1527 goto setup_error;
1528 }
1529
1530 DBG("Disabling all enabled kernel events");
1531
1532 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1533 cmd_ctx->session->kernel_session);
1534 if (chan == NULL) {
1535 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1536 goto error;
1537 }
1538
1539 /* For each event in the kernel session */
1540 cds_list_for_each_entry(ev, &chan->events_list.head, list) {
1541 DBG("Disabling kernel event %s for channel %s.",
1542 ev->event->name, cmd_ctx->lsm->u.disable.channel_name);
1543 ret = kernel_disable_event(ev);
1544 if (ret < 0) {
1545 continue;
1546 }
1547 }
1548
1549 /* Quiescent wait after event disable */
1550 kernel_wait_quiescent(kernel_tracer_fd);
1551 ret = LTTCOMM_OK;
1552 break;
1553 }
1554 case LTTNG_KERNEL_ENABLE_CHANNEL:
1555 {
1556 struct ltt_kernel_channel *chan;
1557
1558 /* Setup lttng message with no payload */
1559 ret = setup_lttng_msg(cmd_ctx, 0);
1560 if (ret < 0) {
1561 goto setup_error;
1562 }
1563
1564 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1565 cmd_ctx->session->kernel_session);
1566 if (chan == NULL) {
1567 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1568 goto error;
1569 } else if (chan->enabled == 0) {
1570 ret = kernel_enable_channel(chan);
1571 if (ret < 0) {
1572 if (ret != EEXIST) {
1573 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1574 }
1575 goto error;
1576 }
1577 }
1578
1579 kernel_wait_quiescent(kernel_tracer_fd);
1580 ret = LTTCOMM_OK;
1581 break;
1582 }
1583 case LTTNG_KERNEL_ENABLE_EVENT:
1584 {
1585 struct ltt_kernel_channel *chan;
1586 struct ltt_kernel_event *ev;
1587
1588 /* Setup lttng message with no payload */
1589 ret = setup_lttng_msg(cmd_ctx, 0);
1590 if (ret < 0) {
1591 goto setup_error;
1592 }
1593
1594 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1595 cmd_ctx->session->kernel_session);
1596 if (chan == NULL) {
1597 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1598 goto error;
1599 }
1600
1601 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, chan);
1602 if (ev == NULL) {
1603 DBG("Creating kernel event %s for channel %s.",
1604 cmd_ctx->lsm->u.enable.event.name, chan->channel->name);
1605 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, chan);
1606 } else {
1607 DBG("Enabling kernel event %s for channel %s.",
1608 cmd_ctx->lsm->u.enable.event.name, chan->channel->name);
1609 ret = kernel_enable_event(ev);
1610 }
1611
1612 if (ret < 0) {
1613 ret = LTTCOMM_KERN_ENABLE_FAIL;
1614 goto error;
1615 }
1616
1617 kernel_wait_quiescent(kernel_tracer_fd);
1618 ret = LTTCOMM_OK;
1619 break;
1620 }
1621 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1622 {
1623 int pos, size;
1624 char *event_list, *event, *ptr;
1625 struct ltt_kernel_channel *chan;
1626 struct ltt_kernel_event *ev;
1627 struct lttng_event ev_attr;
1628
1629 /* Setup lttng message with no payload */
1630 ret = setup_lttng_msg(cmd_ctx, 0);
1631 if (ret < 0) {
1632 goto setup_error;
1633 }
1634
1635 DBG("Enabling all kernel event");
1636
1637 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1638 cmd_ctx->session->kernel_session);
1639 if (chan == NULL) {
1640 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1641 goto error;
1642 }
1643
1644 /* For each event in the kernel session */
1645 cds_list_for_each_entry(ev, &chan->events_list.head, list) {
1646 DBG("Enabling kernel event %s for channel %s.",
1647 ev->event->name, chan->channel->name);
1648 ret = kernel_enable_event(ev);
1649 if (ret < 0) {
1650 continue;
1651 }
1652 }
1653
1654 size = kernel_list_events(kernel_tracer_fd, &event_list);
1655 if (size < 0) {
1656 ret = LTTCOMM_KERN_LIST_FAIL;
1657 goto error;
1658 }
1659
1660 ptr = event_list;
1661 while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
1662 ev = get_kernel_event_by_name(event, chan);
1663 if (ev == NULL) {
1664 strncpy(ev_attr.name, event, LTTNG_SYM_NAME_LEN);
1665 /* Default event type for enable all */
1666 ev_attr.type = LTTNG_EVENT_TRACEPOINT;
1667 /* Enable each single tracepoint event */
1668 ret = kernel_create_event(&ev_attr, chan);
1669 if (ret < 0) {
1670 /* Ignore error here and continue */
1671 }
1672 }
1673
1674 /* Move pointer to the next line */
1675 ptr += pos + 1;
1676 free(event);
1677 }
1678
1679 free(event_list);
1680
1681 /* Quiescent wait after event enable */
1682 kernel_wait_quiescent(kernel_tracer_fd);
1683 ret = LTTCOMM_OK;
1684 break;
1685 }
1686 case LTTNG_KERNEL_LIST_EVENTS:
1687 {
1688 char *event_list;
1689 ssize_t size = 0;
1690
1691 DBG("Listing kernel events");
1692
1693 size = kernel_list_events(kernel_tracer_fd, &event_list);
1694 if (size < 0) {
1695 ret = LTTCOMM_KERN_LIST_FAIL;
1696 goto error;
1697 }
1698
1699 /*
1700 * Setup lttng message with payload size set to the event list size in
1701 * bytes and then copy list into the llm payload.
1702 */
1703 ret = setup_lttng_msg(cmd_ctx, size);
1704 if (ret < 0) {
1705 goto setup_error;
1706 }
1707
1708 /* Copy event list into message payload */
1709 memcpy(cmd_ctx->llm->payload, event_list, size);
1710
1711 free(event_list);
1712
1713 ret = LTTCOMM_OK;
1714 break;
1715 }
1716 case LTTNG_START_TRACE:
1717 {
1718 struct ltt_kernel_channel *chan;
1719
1720 /* Setup lttng message with no payload */
1721 ret = setup_lttng_msg(cmd_ctx, 0);
1722 if (ret < 0) {
1723 goto setup_error;
1724 }
1725
1726 /* Kernel tracing */
1727 if (cmd_ctx->session->kernel_session != NULL) {
1728 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1729 DBG("Open kernel metadata");
1730 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1731 cmd_ctx->session->path);
1732 if (ret < 0) {
1733 ret = LTTCOMM_KERN_META_FAIL;
1734 goto error;
1735 }
1736 }
1737
1738 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1739 DBG("Opening kernel metadata stream");
1740 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1741 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1742 if (ret < 0) {
1743 ERR("Kernel create metadata stream failed");
1744 ret = LTTCOMM_KERN_STREAM_FAIL;
1745 goto error;
1746 }
1747 }
1748 }
1749
1750 /* For each channel */
1751 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1752 if (chan->stream_count == 0) {
1753 ret = kernel_open_channel_stream(chan);
1754 if (ret < 0) {
1755 ERR("Kernel create channel stream failed");
1756 ret = LTTCOMM_KERN_STREAM_FAIL;
1757 goto error;
1758 }
1759 /* Update the stream global counter */
1760 cmd_ctx->session->kernel_session->stream_count_global += ret;
1761 }
1762 }
1763
1764 DBG("Start kernel tracing");
1765 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1766 if (ret < 0) {
1767 ERR("Kernel start session failed");
1768 ret = LTTCOMM_KERN_START_FAIL;
1769 goto error;
1770 }
1771
1772 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1773 if (ret < 0) {
1774 ret = LTTCOMM_KERN_START_FAIL;
1775 goto error;
1776 }
1777
1778 /* Quiescent wait after starting trace */
1779 kernel_wait_quiescent(kernel_tracer_fd);
1780 }
1781
1782 /* TODO: Start all UST traces */
1783
1784 ret = LTTCOMM_OK;
1785 break;
1786 }
1787 case LTTNG_STOP_TRACE:
1788 {
1789 struct ltt_kernel_channel *chan;
1790 /* Setup lttng message with no payload */
1791 ret = setup_lttng_msg(cmd_ctx, 0);
1792 if (ret < 0) {
1793 goto setup_error;
1794 }
1795
1796 /* Kernel tracer */
1797 if (cmd_ctx->session->kernel_session != NULL) {
1798 DBG("Stop kernel tracing");
1799
1800 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
1801 if (ret < 0) {
1802 ERR("Kernel metadata flush failed");
1803 }
1804
1805 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1806 ret = kernel_flush_buffer(chan);
1807 if (ret < 0) {
1808 ERR("Kernel flush buffer error");
1809 }
1810 }
1811
1812 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
1813 if (ret < 0) {
1814 ERR("Kernel stop session failed");
1815 ret = LTTCOMM_KERN_STOP_FAIL;
1816 goto error;
1817 }
1818
1819 /* Quiescent wait after stopping trace */
1820 kernel_wait_quiescent(kernel_tracer_fd);
1821 }
1822
1823 /* TODO : User-space tracer */
1824
1825 ret = LTTCOMM_OK;
1826 break;
1827 }
1828 case LTTNG_CREATE_SESSION:
1829 {
1830 /* Setup lttng message with no payload */
1831 ret = setup_lttng_msg(cmd_ctx, 0);
1832 if (ret < 0) {
1833 goto setup_error;
1834 }
1835
1836 ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path);
1837 if (ret < 0) {
1838 if (ret == -EEXIST) {
1839 ret = LTTCOMM_EXIST_SESS;
1840 } else {
1841 ret = LTTCOMM_FATAL;
1842 }
1843 goto error;
1844 }
1845
1846 ret = LTTCOMM_OK;
1847 break;
1848 }
1849 case LTTNG_DESTROY_SESSION:
1850 {
1851 /* Setup lttng message with no payload */
1852 ret = setup_lttng_msg(cmd_ctx, 0);
1853 if (ret < 0) {
1854 goto setup_error;
1855 }
1856
1857 /* Clean kernel session teardown */
1858 teardown_kernel_session(cmd_ctx->session);
1859
1860 ret = destroy_session(cmd_ctx->lsm->session_name);
1861 if (ret < 0) {
1862 ret = LTTCOMM_FATAL;
1863 goto error;
1864 }
1865
1866 /*
1867 * Must notify the kernel thread here to update it's pollfd in order to
1868 * remove the channel(s)' fd just destroyed.
1869 */
1870 ret = notify_kernel_pollfd();
1871 if (ret < 0) {
1872 ret = LTTCOMM_FATAL;
1873 goto error;
1874 }
1875
1876 ret = LTTCOMM_OK;
1877 break;
1878 }
1879 /*
1880 case LTTNG_LIST_TRACES:
1881 {
1882 unsigned int trace_count;
1883
1884 trace_count = get_trace_count_per_session(cmd_ctx->session);
1885 if (trace_count == 0) {
1886 ret = LTTCOMM_NO_TRACE;
1887 goto error;
1888 }
1889
1890 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
1891 if (ret < 0) {
1892 goto setup_error;
1893 }
1894
1895 get_traces_per_session(cmd_ctx->session,
1896 (struct lttng_trace *)(cmd_ctx->llm->payload));
1897
1898 ret = LTTCOMM_OK;
1899 break;
1900 }
1901 */
1902 /*
1903 case UST_CREATE_TRACE:
1904 {
1905 ret = setup_lttng_msg(cmd_ctx, 0);
1906 if (ret < 0) {
1907 goto setup_error;
1908 }
1909
1910 ret = ust_create_trace(cmd_ctx);
1911 if (ret < 0) {
1912 goto error;
1913 }
1914 break;
1915 }
1916 */
1917 case LTTNG_LIST_TRACEABLE_APPS:
1918 {
1919 unsigned int app_count;
1920
1921 app_count = get_app_count();
1922 DBG("Traceable application count : %d", app_count);
1923 if (app_count == 0) {
1924 ret = LTTCOMM_NO_APPS;
1925 goto error;
1926 }
1927
1928 ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
1929 if (ret < 0) {
1930 goto setup_error;
1931 }
1932
1933 get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
1934
1935 ret = LTTCOMM_OK;
1936 break;
1937 }
1938 /*
1939 case UST_START_TRACE:
1940 {
1941 ret = setup_lttng_msg(cmd_ctx, 0);
1942 if (ret < 0) {
1943 goto setup_error;
1944 }
1945
1946 ret = ust_start_trace(cmd_ctx);
1947 if (ret < 0) {
1948 goto setup_error;
1949 }
1950 break;
1951 }
1952 case UST_STOP_TRACE:
1953 {
1954 ret = setup_lttng_msg(cmd_ctx, 0);
1955 if (ret < 0) {
1956 goto setup_error;
1957 }
1958
1959 ret = ust_stop_trace(cmd_ctx);
1960 if (ret < 0) {
1961 goto setup_error;
1962 }
1963 break;
1964 }
1965 */
1966 case LTTNG_LIST_SESSIONS:
1967 {
1968 lock_session_list();
1969
1970 if (session_list_ptr->count == 0) {
1971 ret = LTTCOMM_NO_SESSION;
1972 goto error;
1973 }
1974
1975 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
1976 session_list_ptr->count);
1977 if (ret < 0) {
1978 goto setup_error;
1979 }
1980
1981 /* Filled the session array */
1982 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
1983
1984 unlock_session_list();
1985
1986 ret = LTTCOMM_OK;
1987 break;
1988 }
1989 default:
1990 /* Undefined command */
1991 ret = setup_lttng_msg(cmd_ctx, 0);
1992 if (ret < 0) {
1993 goto setup_error;
1994 }
1995
1996 ret = LTTCOMM_UND;
1997 break;
1998 }
1999
2000 /* Set return code */
2001 cmd_ctx->llm->ret_code = ret;
2002
2003 if (cmd_ctx->session) {
2004 unlock_session(cmd_ctx->session);
2005 }
2006
2007 return ret;
2008
2009 error:
2010 if (cmd_ctx->llm == NULL) {
2011 DBG("Missing llm structure. Allocating one.");
2012 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2013 goto setup_error;
2014 }
2015 }
2016 /* Notify client of error */
2017 cmd_ctx->llm->ret_code = ret;
2018
2019 setup_error:
2020 if (cmd_ctx->session) {
2021 unlock_session(cmd_ctx->session);
2022 }
2023 return ret;
2024 }
2025
2026 /*
2027 * thread_manage_clients
2028 *
2029 * This thread manage all clients request using the unix
2030 * client socket for communication.
2031 */
2032 static void *thread_manage_clients(void *data)
2033 {
2034 int sock = 0, ret;
2035 struct command_ctx *cmd_ctx = NULL;
2036 struct pollfd pollfd[2];
2037
2038 DBG("[thread] Manage client started");
2039
2040 ret = lttcomm_listen_unix_sock(client_sock);
2041 if (ret < 0) {
2042 goto error;
2043 }
2044
2045 /* First fd is always the quit pipe */
2046 pollfd[0].fd = thread_quit_pipe[0];
2047
2048 /* Apps socket */
2049 pollfd[1].fd = client_sock;
2050 pollfd[1].events = POLLIN;
2051
2052 /* Notify parent pid that we are ready
2053 * to accept command for client side.
2054 */
2055 if (opt_sig_parent) {
2056 kill(ppid, SIGCHLD);
2057 }
2058
2059 while (1) {
2060 DBG("Accepting client command ...");
2061
2062 /* Inifinite blocking call, waiting for transmission */
2063 ret = poll(pollfd, 2, -1);
2064 if (ret < 0) {
2065 perror("poll client thread");
2066 goto error;
2067 }
2068
2069 /* Thread quit pipe has been closed. Killing thread. */
2070 if (pollfd[0].revents == POLLNVAL) {
2071 goto error;
2072 } else if (pollfd[1].revents == POLLERR) {
2073 ERR("Client socket poll error");
2074 goto error;
2075 }
2076
2077 sock = lttcomm_accept_unix_sock(client_sock);
2078 if (sock < 0) {
2079 goto error;
2080 }
2081
2082 /* Allocate context command to process the client request */
2083 cmd_ctx = malloc(sizeof(struct command_ctx));
2084
2085 /* Allocate data buffer for reception */
2086 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2087 cmd_ctx->llm = NULL;
2088 cmd_ctx->session = NULL;
2089
2090 /*
2091 * Data is received from the lttng client. The struct
2092 * lttcomm_session_msg (lsm) contains the command and data request of
2093 * the client.
2094 */
2095 DBG("Receiving data from client ...");
2096 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2097 if (ret <= 0) {
2098 continue;
2099 }
2100
2101 // TODO: Validate cmd_ctx including sanity check for security purpose.
2102
2103 /*
2104 * This function dispatch the work to the kernel or userspace tracer
2105 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2106 * informations for the client. The command context struct contains
2107 * everything this function may needs.
2108 */
2109 ret = process_client_msg(cmd_ctx);
2110 if (ret < 0) {
2111 /* TODO: Inform client somehow of the fatal error. At this point,
2112 * ret < 0 means that a malloc failed (ENOMEM). */
2113 /* Error detected but still accept command */
2114 clean_command_ctx(&cmd_ctx);
2115 continue;
2116 }
2117
2118 DBG("Sending response (size: %d, retcode: %d)",
2119 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2120 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2121 if (ret < 0) {
2122 ERR("Failed to send data back to client");
2123 }
2124
2125 clean_command_ctx(&cmd_ctx);
2126
2127 /* End of transmission */
2128 close(sock);
2129 }
2130
2131 error:
2132 DBG("Client thread dying");
2133 if (client_sock) {
2134 close(client_sock);
2135 }
2136 if (sock) {
2137 close(sock);
2138 }
2139
2140 unlink(client_unix_sock_path);
2141
2142 clean_command_ctx(&cmd_ctx);
2143 return NULL;
2144 }
2145
2146
2147 /*
2148 * usage function on stderr
2149 */
2150 static void usage(void)
2151 {
2152 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2153 fprintf(stderr, " -h, --help Display this usage.\n");
2154 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2155 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2156 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2157 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2158 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2159 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2160 fprintf(stderr, " -V, --version Show version number.\n");
2161 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2162 fprintf(stderr, " -q, --quiet No output at all.\n");
2163 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2164 }
2165
2166 /*
2167 * daemon argument parsing
2168 */
2169 static int parse_args(int argc, char **argv)
2170 {
2171 int c;
2172
2173 static struct option long_options[] = {
2174 { "client-sock", 1, 0, 'c' },
2175 { "apps-sock", 1, 0, 'a' },
2176 { "kconsumerd-cmd-sock", 1, 0, 0 },
2177 { "kconsumerd-err-sock", 1, 0, 0 },
2178 { "daemonize", 0, 0, 'd' },
2179 { "sig-parent", 0, 0, 'S' },
2180 { "help", 0, 0, 'h' },
2181 { "group", 1, 0, 'g' },
2182 { "version", 0, 0, 'V' },
2183 { "quiet", 0, 0, 'q' },
2184 { "verbose", 0, 0, 'v' },
2185 { NULL, 0, 0, 0 }
2186 };
2187
2188 while (1) {
2189 int option_index = 0;
2190 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
2191 if (c == -1) {
2192 break;
2193 }
2194
2195 switch (c) {
2196 case 0:
2197 fprintf(stderr, "option %s", long_options[option_index].name);
2198 if (optarg) {
2199 fprintf(stderr, " with arg %s\n", optarg);
2200 }
2201 break;
2202 case 'c':
2203 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2204 break;
2205 case 'a':
2206 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2207 break;
2208 case 'd':
2209 opt_daemon = 1;
2210 break;
2211 case 'g':
2212 opt_tracing_group = strdup(optarg);
2213 break;
2214 case 'h':
2215 usage();
2216 exit(EXIT_FAILURE);
2217 case 'V':
2218 fprintf(stdout, "%s\n", VERSION);
2219 exit(EXIT_SUCCESS);
2220 case 'S':
2221 opt_sig_parent = 1;
2222 break;
2223 case 'E':
2224 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2225 break;
2226 case 'C':
2227 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2228 break;
2229 case 'q':
2230 opt_quiet = 1;
2231 break;
2232 case 'v':
2233 opt_verbose = 1;
2234 break;
2235 default:
2236 /* Unknown option or other error.
2237 * Error is printed by getopt, just return */
2238 return -1;
2239 }
2240 }
2241
2242 return 0;
2243 }
2244
2245 /*
2246 * init_daemon_socket
2247 *
2248 * Creates the two needed socket by the daemon.
2249 * apps_sock - The communication socket for all UST apps.
2250 * client_sock - The communication of the cli tool (lttng).
2251 */
2252 static int init_daemon_socket()
2253 {
2254 int ret = 0;
2255 mode_t old_umask;
2256
2257 old_umask = umask(0);
2258
2259 /* Create client tool unix socket */
2260 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2261 if (client_sock < 0) {
2262 ERR("Create unix sock failed: %s", client_unix_sock_path);
2263 ret = -1;
2264 goto end;
2265 }
2266
2267 /* File permission MUST be 660 */
2268 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2269 if (ret < 0) {
2270 ERR("Set file permissions failed: %s", client_unix_sock_path);
2271 perror("chmod");
2272 goto end;
2273 }
2274
2275 /* Create the application unix socket */
2276 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2277 if (apps_sock < 0) {
2278 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2279 ret = -1;
2280 goto end;
2281 }
2282
2283 /* File permission MUST be 666 */
2284 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2285 if (ret < 0) {
2286 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2287 perror("chmod");
2288 goto end;
2289 }
2290
2291 end:
2292 umask(old_umask);
2293 return ret;
2294 }
2295
2296 /*
2297 * check_existing_daemon
2298 *
2299 * Check if the global socket is available.
2300 * If yes, error is returned.
2301 */
2302 static int check_existing_daemon()
2303 {
2304 int ret;
2305
2306 ret = access(client_unix_sock_path, F_OK);
2307 if (ret == 0) {
2308 ret = access(apps_unix_sock_path, F_OK);
2309 }
2310
2311 return ret;
2312 }
2313
2314 /*
2315 * set_permissions
2316 *
2317 * Set the tracing group gid onto the client socket.
2318 *
2319 * Race window between mkdir and chown is OK because we are going from
2320 * more permissive (root.root) to les permissive (root.tracing).
2321 */
2322 static int set_permissions(void)
2323 {
2324 int ret;
2325 struct group *grp;
2326
2327 /* Decide which group name to use */
2328 (opt_tracing_group != NULL) ?
2329 (grp = getgrnam(opt_tracing_group)) :
2330 (grp = getgrnam(default_tracing_group));
2331
2332 if (grp == NULL) {
2333 if (is_root) {
2334 WARN("No tracing group detected");
2335 ret = 0;
2336 } else {
2337 ERR("Missing tracing group. Aborting execution.");
2338 ret = -1;
2339 }
2340 goto end;
2341 }
2342
2343 /* Set lttng run dir */
2344 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
2345 if (ret < 0) {
2346 ERR("Unable to set group on " LTTNG_RUNDIR);
2347 perror("chown");
2348 }
2349
2350 /* lttng client socket path */
2351 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
2352 if (ret < 0) {
2353 ERR("Unable to set group on %s", client_unix_sock_path);
2354 perror("chown");
2355 }
2356
2357 /* kconsumerd error socket path */
2358 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
2359 if (ret < 0) {
2360 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2361 perror("chown");
2362 }
2363
2364 DBG("All permissions are set");
2365
2366 end:
2367 return ret;
2368 }
2369
2370 /*
2371 * create_kernel_poll_pipe
2372 *
2373 * Create the pipe used to wake up the kernel thread.
2374 */
2375 static int create_kernel_poll_pipe(void)
2376 {
2377 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2378 }
2379
2380 /*
2381 * create_lttng_rundir
2382 *
2383 * Create the lttng run directory needed for all
2384 * global sockets and pipe.
2385 */
2386 static int create_lttng_rundir(void)
2387 {
2388 int ret;
2389
2390 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2391 if (ret < 0) {
2392 if (errno != EEXIST) {
2393 ERR("Unable to create " LTTNG_RUNDIR);
2394 goto error;
2395 } else {
2396 ret = 0;
2397 }
2398 }
2399
2400 error:
2401 return ret;
2402 }
2403
2404 /*
2405 * set_kconsumerd_sockets
2406 *
2407 * Setup sockets and directory needed by the kconsumerd
2408 * communication with the session daemon.
2409 */
2410 static int set_kconsumerd_sockets(void)
2411 {
2412 int ret;
2413
2414 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2415 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2416 }
2417
2418 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2419 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2420 }
2421
2422 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2423 if (ret < 0) {
2424 if (errno != EEXIST) {
2425 ERR("Failed to create " KCONSUMERD_PATH);
2426 goto error;
2427 }
2428 ret = 0;
2429 }
2430
2431 /* Create the kconsumerd error unix socket */
2432 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2433 if (kconsumerd_err_sock < 0) {
2434 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2435 ret = -1;
2436 goto error;
2437 }
2438
2439 /* File permission MUST be 660 */
2440 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2441 if (ret < 0) {
2442 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2443 perror("chmod");
2444 goto error;
2445 }
2446
2447 error:
2448 return ret;
2449 }
2450
2451 /*
2452 * sighandler
2453 *
2454 * Signal handler for the daemon
2455 */
2456 static void sighandler(int sig)
2457 {
2458 switch (sig) {
2459 case SIGPIPE:
2460 DBG("SIGPIPE catched");
2461 return;
2462 case SIGINT:
2463 DBG("SIGINT catched");
2464 cleanup();
2465 break;
2466 case SIGTERM:
2467 DBG("SIGTERM catched");
2468 cleanup();
2469 break;
2470 default:
2471 break;
2472 }
2473
2474 exit(EXIT_SUCCESS);
2475 }
2476
2477 /*
2478 * set_signal_handler
2479 *
2480 * Setup signal handler for :
2481 * SIGINT, SIGTERM, SIGPIPE
2482 */
2483 static int set_signal_handler(void)
2484 {
2485 int ret = 0;
2486 struct sigaction sa;
2487 sigset_t sigset;
2488
2489 if ((ret = sigemptyset(&sigset)) < 0) {
2490 perror("sigemptyset");
2491 return ret;
2492 }
2493
2494 sa.sa_handler = sighandler;
2495 sa.sa_mask = sigset;
2496 sa.sa_flags = 0;
2497 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2498 perror("sigaction");
2499 return ret;
2500 }
2501
2502 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2503 perror("sigaction");
2504 return ret;
2505 }
2506
2507 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2508 perror("sigaction");
2509 return ret;
2510 }
2511
2512 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2513
2514 return ret;
2515 }
2516
2517 /*
2518 * set_ulimit
2519 *
2520 * Set open files limit to unlimited. This daemon can open a large number of
2521 * file descriptors in order to consumer multiple kernel traces.
2522 */
2523 static void set_ulimit(void)
2524 {
2525 int ret;
2526 struct rlimit lim;
2527
2528 /* The kernel does not allowed an infinite limit for open files */
2529 lim.rlim_cur = 65535;
2530 lim.rlim_max = 65535;
2531
2532 ret = setrlimit(RLIMIT_NOFILE, &lim);
2533 if (ret < 0) {
2534 perror("failed to set open files limit");
2535 }
2536 }
2537
2538 /*
2539 * main
2540 */
2541 int main(int argc, char **argv)
2542 {
2543 int ret = 0;
2544 void *status;
2545 const char *home_path;
2546
2547 /* Create thread quit pipe */
2548 if (init_thread_quit_pipe() < 0) {
2549 goto exit;
2550 }
2551
2552 /* Parse arguments */
2553 progname = argv[0];
2554 if ((ret = parse_args(argc, argv) < 0)) {
2555 goto exit;
2556 }
2557
2558 /* Daemonize */
2559 if (opt_daemon) {
2560 ret = daemon(0, 0);
2561 if (ret < 0) {
2562 perror("daemon");
2563 goto exit;
2564 }
2565 }
2566
2567 /* Check if daemon is UID = 0 */
2568 is_root = !getuid();
2569
2570 if (is_root) {
2571 ret = create_lttng_rundir();
2572 if (ret < 0) {
2573 goto exit;
2574 }
2575
2576 if (strlen(apps_unix_sock_path) == 0) {
2577 snprintf(apps_unix_sock_path, PATH_MAX,
2578 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2579 }
2580
2581 if (strlen(client_unix_sock_path) == 0) {
2582 snprintf(client_unix_sock_path, PATH_MAX,
2583 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2584 }
2585 } else {
2586 home_path = get_home_dir();
2587 if (home_path == NULL) {
2588 /* TODO: Add --socket PATH option */
2589 ERR("Can't get HOME directory for sockets creation.");
2590 goto exit;
2591 }
2592
2593 if (strlen(apps_unix_sock_path) == 0) {
2594 snprintf(apps_unix_sock_path, PATH_MAX,
2595 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2596 }
2597
2598 /* Set the cli tool unix socket path */
2599 if (strlen(client_unix_sock_path) == 0) {
2600 snprintf(client_unix_sock_path, PATH_MAX,
2601 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2602 }
2603 }
2604
2605 DBG("Client socket path %s", client_unix_sock_path);
2606 DBG("Application socket path %s", apps_unix_sock_path);
2607
2608 /*
2609 * See if daemon already exist. If any of the two socket needed by the
2610 * daemon are present, this test fails. However, if the daemon is killed
2611 * with a SIGKILL, those unix socket must be unlinked by hand.
2612 */
2613 if ((ret = check_existing_daemon()) == 0) {
2614 ERR("Already running daemon.\n");
2615 /*
2616 * We do not goto error because we must not cleanup() because a daemon
2617 * is already running.
2618 */
2619 goto exit;
2620 }
2621
2622 /* After this point, we can safely call cleanup() so goto error is used */
2623
2624 /*
2625 * These actions must be executed as root. We do that *after* setting up
2626 * the sockets path because we MUST make the check for another daemon using
2627 * those paths *before* trying to set the kernel consumer sockets and init
2628 * kernel tracer.
2629 */
2630 if (is_root) {
2631 ret = set_kconsumerd_sockets();
2632 if (ret < 0) {
2633 goto error;
2634 }
2635
2636 /* Setup kernel tracer */
2637 init_kernel_tracer();
2638
2639 /* Set ulimit for open files */
2640 set_ulimit();
2641 }
2642
2643 if (set_signal_handler() < 0) {
2644 goto error;
2645 }
2646
2647 /* Setup the needed unix socket */
2648 if (init_daemon_socket() < 0) {
2649 goto error;
2650 }
2651
2652 /* Set credentials to socket */
2653 if (is_root && (set_permissions() < 0)) {
2654 goto error;
2655 }
2656
2657 /* Get parent pid if -S, --sig-parent is specified. */
2658 if (opt_sig_parent) {
2659 ppid = getppid();
2660 }
2661
2662 /* Setup the kernel pipe for waking up the kernel thread */
2663 if (create_kernel_poll_pipe() < 0) {
2664 goto error;
2665 }
2666
2667 /*
2668 * Get session list pointer. This pointer MUST NOT be free().
2669 * This list is statically declared in session.c
2670 */
2671 session_list_ptr = get_session_list();
2672
2673 while (1) {
2674 /* Create thread to manage the client socket */
2675 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2676 if (ret != 0) {
2677 perror("pthread_create");
2678 goto error;
2679 }
2680
2681 /* Create thread to manage application socket */
2682 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2683 if (ret != 0) {
2684 perror("pthread_create");
2685 goto error;
2686 }
2687
2688 /* Create kernel thread to manage kernel event */
2689 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2690 if (ret != 0) {
2691 perror("pthread_create");
2692 goto error;
2693 }
2694
2695 ret = pthread_join(client_thread, &status);
2696 if (ret != 0) {
2697 perror("pthread_join");
2698 goto error;
2699 }
2700 }
2701
2702 cleanup();
2703 exit(EXIT_SUCCESS);
2704
2705 error:
2706 cleanup();
2707
2708 exit:
2709 exit(EXIT_FAILURE);
2710 }
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