fc1ef92248289dbf7a9f7a573ce24740a6acf129
[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; only version 2
7 * of the License.
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 /* Const values */
55 const char default_home_dir[] = DEFAULT_HOME_DIR;
56 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
57 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
58 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
59
60 /* Variables */
61 int opt_verbose; /* Not static for lttngerr.h */
62 int opt_quiet; /* Not static for lttngerr.h */
63
64 const char *progname;
65 const char *opt_tracing_group;
66 static int opt_sig_parent;
67 static int opt_daemon;
68 static int is_root; /* Set to 1 if the daemon is running as root */
69 static pid_t ppid; /* Parent PID for --sig-parent option */
70 static pid_t kconsumerd_pid;
71 static struct pollfd *kernel_pollfd;
72
73 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
74 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
75 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
76 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
77
78 /* Sockets and FDs */
79 static int client_sock;
80 static int apps_sock;
81 static int kconsumerd_err_sock;
82 static int kconsumerd_cmd_sock;
83 static int kernel_tracer_fd;
84 static int kernel_poll_pipe[2];
85
86 /*
87 * Quit pipe for all threads. This permits a single cancellation point
88 * for all threads when receiving an event on the pipe.
89 */
90 static int thread_quit_pipe[2];
91
92 /* Pthread, Mutexes and Semaphores */
93 static pthread_t kconsumerd_thread;
94 static pthread_t apps_thread;
95 static pthread_t client_thread;
96 static pthread_t kernel_thread;
97 static sem_t kconsumerd_sem;
98
99 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
100
101 /*
102 * Pointer initialized before thread creation.
103 *
104 * This points to the tracing session list containing the session count and a
105 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
106 * MUST NOT be taken if you call a public function in session.c.
107 *
108 * The lock is nested inside the structure: session_list_ptr->lock. Please use
109 * lock_session_list and unlock_session_list for lock acquisition.
110 */
111 static struct ltt_session_list *session_list_ptr;
112
113 /*
114 * Init quit pipe.
115 *
116 * Return -1 on error or 0 if all pipes are created.
117 */
118 static int init_thread_quit_pipe(void)
119 {
120 int ret;
121
122 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
123 if (ret < 0) {
124 perror("thread quit pipe");
125 goto error;
126 }
127
128 error:
129 return ret;
130 }
131
132 /*
133 * Complete teardown of a kernel session. This free all data structure related
134 * to a kernel session and update counter.
135 */
136 static void teardown_kernel_session(struct ltt_session *session)
137 {
138 if (session->kernel_session != NULL) {
139 DBG("Tearing down kernel session");
140 trace_destroy_kernel_session(session->kernel_session);
141 /* Extra precaution */
142 session->kernel_session = NULL;
143 }
144 }
145
146 /*
147 * Cleanup the daemon
148 */
149 static void cleanup()
150 {
151 int ret;
152 char *cmd;
153 struct ltt_session *sess, *stmp;
154
155 DBG("Cleaning up");
156
157 /* <fun> */
158 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
159 "Matthew, BEET driven development works!%c[%dm",
160 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
161 /* </fun> */
162
163 /* Stopping all threads */
164 DBG("Terminating all threads");
165 close(thread_quit_pipe[0]);
166 close(thread_quit_pipe[1]);
167
168 DBG("Removing %s directory", LTTNG_RUNDIR);
169 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
170 if (ret < 0) {
171 ERR("asprintf failed. Something is really wrong!");
172 }
173
174 /* Remove lttng run directory */
175 ret = system(cmd);
176 if (ret < 0) {
177 ERR("Unable to clean " LTTNG_RUNDIR);
178 }
179
180 DBG("Cleaning up all session");
181
182 /* Destroy session list mutex */
183 if (session_list_ptr != NULL) {
184 pthread_mutex_destroy(&session_list_ptr->lock);
185
186 /* Cleanup ALL session */
187 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
188 teardown_kernel_session(sess);
189 // TODO complete session cleanup (including UST)
190 }
191 }
192
193 pthread_mutex_destroy(&kconsumerd_pid_mutex);
194
195 DBG("Closing kernel fd");
196 close(kernel_tracer_fd);
197 }
198
199 /*
200 * Send data on a unix socket using the liblttsessiondcomm API.
201 *
202 * Return lttcomm error code.
203 */
204 static int send_unix_sock(int sock, void *buf, size_t len)
205 {
206 /* Check valid length */
207 if (len <= 0) {
208 return -1;
209 }
210
211 return lttcomm_send_unix_sock(sock, buf, len);
212 }
213
214 /*
215 * Free memory of a command context structure.
216 */
217 static void clean_command_ctx(struct command_ctx **cmd_ctx)
218 {
219 DBG("Clean command context structure");
220 if (*cmd_ctx) {
221 if ((*cmd_ctx)->llm) {
222 free((*cmd_ctx)->llm);
223 }
224 if ((*cmd_ctx)->lsm) {
225 free((*cmd_ctx)->lsm);
226 }
227 free(*cmd_ctx);
228 *cmd_ctx = NULL;
229 }
230 }
231
232 /*
233 * Send all stream fds of kernel channel to the consumer.
234 */
235 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
236 {
237 int ret;
238 size_t nb_fd;
239 struct ltt_kernel_stream *stream;
240 struct lttcomm_kconsumerd_header lkh;
241 struct lttcomm_kconsumerd_msg lkm;
242
243 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
244
245 nb_fd = channel->stream_count;
246
247 /* Setup header */
248 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
249 lkh.cmd_type = ADD_STREAM;
250
251 DBG("Sending kconsumerd header");
252
253 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
254 if (ret < 0) {
255 perror("send kconsumerd header");
256 goto error;
257 }
258
259 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
260 if (stream->fd != 0) {
261 lkm.fd = stream->fd;
262 lkm.state = stream->state;
263 lkm.max_sb_size = channel->channel->attr.subbuf_size;
264 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
265
266 DBG("Sending fd %d to kconsumerd", lkm.fd);
267
268 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
269 if (ret < 0) {
270 perror("send kconsumerd fd");
271 goto error;
272 }
273 }
274 }
275
276 DBG("Kconsumerd channel fds sent");
277
278 return 0;
279
280 error:
281 return ret;
282 }
283
284 /*
285 * Send all stream fds of the kernel session to the consumer.
286 */
287 static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
288 {
289 int ret;
290 struct ltt_kernel_channel *chan;
291 struct lttcomm_kconsumerd_header lkh;
292 struct lttcomm_kconsumerd_msg lkm;
293
294 /* Setup header */
295 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
296 lkh.cmd_type = ADD_STREAM;
297
298 DBG("Sending kconsumerd header for metadata");
299
300 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
301 if (ret < 0) {
302 perror("send kconsumerd header");
303 goto error;
304 }
305
306 DBG("Sending metadata stream fd");
307
308 if (session->metadata_stream_fd != 0) {
309 /* Send metadata stream fd first */
310 lkm.fd = session->metadata_stream_fd;
311 lkm.state = ACTIVE_FD;
312 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
313 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
314
315 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
316 if (ret < 0) {
317 perror("send kconsumerd fd");
318 goto error;
319 }
320 }
321
322 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
323 ret = send_kconsumerd_channel_fds(sock, chan);
324 if (ret < 0) {
325 goto error;
326 }
327 }
328
329 DBG("Kconsumerd fds (metadata and channel streams) sent");
330
331 return 0;
332
333 error:
334 return ret;
335 }
336
337 #ifdef DISABLED
338 /*
339 * Return a socket connected to the libust communication socket of the
340 * application identified by the pid.
341 *
342 * If the pid is not found in the traceable list, return -1 to indicate error.
343 */
344 static int ust_connect_app(pid_t pid)
345 {
346 int sock;
347 struct ltt_traceable_app *lta;
348
349 DBG("Connect to application pid %d", pid);
350
351 lta = find_app_by_pid(pid);
352 if (lta == NULL) {
353 /* App not found */
354 DBG("Application pid %d not found", pid);
355 return -1;
356 }
357
358 sock = ustctl_connect_pid(lta->pid);
359 if (sock < 0) {
360 ERR("Fail connecting to the PID %d", pid);
361 }
362
363 return sock;
364 }
365 #endif /* DISABLED */
366
367 /*
368 * Notify apps by writing 42 to a named pipe using name. Every applications
369 * waiting for a ltt-sessiond will be notified and re-register automatically to
370 * the session daemon.
371 *
372 * Return open or write error value.
373 */
374 static int notify_apps(const char *name)
375 {
376 int fd;
377 int ret = -1;
378
379 DBG("Notify the global application pipe");
380
381 /* Try opening the global pipe */
382 fd = open(name, O_WRONLY);
383 if (fd < 0) {
384 goto error;
385 }
386
387 /* Notify by writing on the pipe */
388 ret = write(fd, "42", 2);
389 if (ret < 0) {
390 perror("write");
391 }
392
393 error:
394 return ret;
395 }
396
397 /*
398 * Setup the outgoing data buffer for the response (llm) by allocating the
399 * right amount of memory and copying the original information from the lsm
400 * structure.
401 *
402 * Return total size of the buffer pointed by buf.
403 */
404 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
405 {
406 int ret, buf_size;
407
408 buf_size = size;
409
410 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
411 if (cmd_ctx->llm == NULL) {
412 perror("malloc");
413 ret = -ENOMEM;
414 goto error;
415 }
416
417 /* Copy common data */
418 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
419 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
420
421 cmd_ctx->llm->data_size = size;
422 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
423
424 return buf_size;
425
426 error:
427 return ret;
428 }
429
430 /*
431 * Update the kernel pollfd set of all channel fd available over all tracing
432 * session. Add the wakeup pipe at the end of the set.
433 */
434 static int update_kernel_pollfd(void)
435 {
436 int i = 0;
437 /*
438 * The wakup pipe and the quit pipe are needed so the number of fds starts
439 * at 2 for those pipes.
440 */
441 unsigned int nb_fd = 2;
442 struct ltt_session *session;
443 struct ltt_kernel_channel *channel;
444
445 DBG("Updating kernel_pollfd");
446
447 /* Get the number of channel of all kernel session */
448 lock_session_list();
449 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
450 lock_session(session);
451 if (session->kernel_session == NULL) {
452 unlock_session(session);
453 continue;
454 }
455 nb_fd += session->kernel_session->channel_count;
456 unlock_session(session);
457 }
458
459 DBG("Resizing kernel_pollfd to size %d", nb_fd);
460
461 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
462 if (kernel_pollfd == NULL) {
463 perror("malloc kernel_pollfd");
464 goto error;
465 }
466
467 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
468 lock_session(session);
469 if (session->kernel_session == NULL) {
470 unlock_session(session);
471 continue;
472 }
473 if (i >= nb_fd) {
474 ERR("To much channel for kernel_pollfd size");
475 unlock_session(session);
476 break;
477 }
478 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
479 kernel_pollfd[i].fd = channel->fd;
480 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
481 i++;
482 }
483 unlock_session(session);
484 }
485 unlock_session_list();
486
487 /* Adding wake up pipe */
488 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
489 kernel_pollfd[nb_fd - 2].events = POLLIN;
490
491 /* Adding the quit pipe */
492 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
493
494 return nb_fd;
495
496 error:
497 unlock_session_list();
498 return -1;
499 }
500
501 /*
502 * Find the channel fd from 'fd' over all tracing session. When found, check
503 * for new channel stream and send those stream fds to the kernel consumer.
504 *
505 * Useful for CPU hotplug feature.
506 */
507 static int update_kernel_stream(int fd)
508 {
509 int ret = 0;
510 struct ltt_session *session;
511 struct ltt_kernel_channel *channel;
512
513 DBG("Updating kernel streams for channel fd %d", fd);
514
515 lock_session_list();
516 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
517 lock_session(session);
518 if (session->kernel_session == NULL) {
519 unlock_session(session);
520 continue;
521 }
522 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
523 if (channel->fd == fd) {
524 DBG("Channel found, updating kernel streams");
525 ret = kernel_open_channel_stream(channel);
526 if (ret < 0) {
527 goto end;
528 }
529 /*
530 * Have we already sent fds to the consumer? If yes, it means that
531 * tracing is started so it is safe to send our updated stream fds.
532 */
533 if (session->kernel_session->kconsumer_fds_sent == 1) {
534 ret = send_kconsumerd_channel_fds(kconsumerd_cmd_sock, channel);
535 if (ret < 0) {
536 goto end;
537 }
538 }
539 goto end;
540 }
541 }
542 unlock_session(session);
543 }
544
545 end:
546 unlock_session_list();
547 if (session) {
548 unlock_session(session);
549 }
550 return ret;
551 }
552
553 /*
554 * This thread manage event coming from the kernel.
555 *
556 * Features supported in this thread:
557 * -) CPU Hotplug
558 */
559 static void *thread_manage_kernel(void *data)
560 {
561 int ret, i, nb_fd = 0;
562 char tmp;
563 int update_poll_flag = 1;
564
565 DBG("Thread manage kernel started");
566
567 while (1) {
568 if (update_poll_flag == 1) {
569 nb_fd = update_kernel_pollfd();
570 if (nb_fd < 0) {
571 goto error;
572 }
573 update_poll_flag = 0;
574 }
575
576 DBG("Polling on %d fds", nb_fd);
577
578 /* Poll infinite value of time */
579 ret = poll(kernel_pollfd, nb_fd, -1);
580 if (ret < 0) {
581 perror("poll kernel thread");
582 goto error;
583 } else if (ret == 0) {
584 /* Should not happen since timeout is infinite */
585 continue;
586 }
587
588 /* Thread quit pipe has been closed. Killing thread. */
589 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
590 goto error;
591 }
592
593 DBG("Kernel poll event triggered");
594
595 /*
596 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
597 * must be updated.
598 */
599 switch (kernel_pollfd[nb_fd - 2].revents) {
600 case POLLIN:
601 ret = read(kernel_poll_pipe[0], &tmp, 1);
602 update_poll_flag = 1;
603 continue;
604 case POLLERR:
605 goto error;
606 default:
607 break;
608 }
609
610 for (i = 0; i < nb_fd; i++) {
611 switch (kernel_pollfd[i].revents) {
612 /*
613 * New CPU detected by the kernel. Adding kernel stream to kernel
614 * session and updating the kernel consumer
615 */
616 case POLLIN | POLLRDNORM:
617 ret = update_kernel_stream(kernel_pollfd[i].fd);
618 if (ret < 0) {
619 continue;
620 }
621 break;
622 }
623 }
624 }
625
626 error:
627 DBG("Kernel thread dying");
628 if (kernel_pollfd) {
629 free(kernel_pollfd);
630 }
631
632 close(kernel_poll_pipe[0]);
633 close(kernel_poll_pipe[1]);
634 return NULL;
635 }
636
637 /*
638 * This thread manage the kconsumerd error sent back to the session daemon.
639 */
640 static void *thread_manage_kconsumerd(void *data)
641 {
642 int sock = 0, ret;
643 enum lttcomm_return_code code;
644 struct pollfd pollfd[2];
645
646 DBG("[thread] Manage kconsumerd started");
647
648 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
649 if (ret < 0) {
650 goto error;
651 }
652
653 /* First fd is always the quit pipe */
654 pollfd[0].fd = thread_quit_pipe[0];
655
656 /* Apps socket */
657 pollfd[1].fd = kconsumerd_err_sock;
658 pollfd[1].events = POLLIN;
659
660 /* Inifinite blocking call, waiting for transmission */
661 ret = poll(pollfd, 2, -1);
662 if (ret < 0) {
663 perror("poll kconsumerd thread");
664 goto error;
665 }
666
667 /* Thread quit pipe has been closed. Killing thread. */
668 if (pollfd[0].revents == POLLNVAL) {
669 goto error;
670 } else if (pollfd[1].revents == POLLERR) {
671 ERR("Kconsumerd err socket poll error");
672 goto error;
673 }
674
675 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
676 if (sock < 0) {
677 goto error;
678 }
679
680 /* Getting status code from kconsumerd */
681 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
682 if (ret <= 0) {
683 goto error;
684 }
685
686 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
687 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
688 if (kconsumerd_cmd_sock < 0) {
689 sem_post(&kconsumerd_sem);
690 perror("kconsumerd connect");
691 goto error;
692 }
693 /* Signal condition to tell that the kconsumerd is ready */
694 sem_post(&kconsumerd_sem);
695 DBG("Kconsumerd command socket ready");
696 } else {
697 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
698 lttcomm_get_readable_code(-code));
699 goto error;
700 }
701
702 /* Wait for any kconsumerd error */
703 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
704 if (ret <= 0) {
705 ERR("Kconsumerd closed the command socket");
706 goto error;
707 }
708
709 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
710
711 error:
712 DBG("Kconsumerd thread dying");
713 if (kconsumerd_err_sock) {
714 close(kconsumerd_err_sock);
715 }
716 if (kconsumerd_cmd_sock) {
717 close(kconsumerd_cmd_sock);
718 }
719 if (sock) {
720 close(sock);
721 }
722
723 unlink(kconsumerd_err_unix_sock_path);
724 unlink(kconsumerd_cmd_unix_sock_path);
725
726 kconsumerd_pid = 0;
727 return NULL;
728 }
729
730 /*
731 * This thread manage the application socket communication
732 */
733 static void *thread_manage_apps(void *data)
734 {
735 int sock = 0, ret;
736 struct pollfd pollfd[2];
737
738 /* TODO: Something more elegant is needed but fine for now */
739 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
740 * for 32-bit vs 64-bit compat processes. */
741 /* replicate in ust with version number */
742 struct {
743 int reg; /* 1:register, 0:unregister */
744 pid_t pid;
745 uid_t uid;
746 } reg_msg;
747
748 DBG("[thread] Manage apps started");
749
750 ret = lttcomm_listen_unix_sock(apps_sock);
751 if (ret < 0) {
752 goto error;
753 }
754
755 /* First fd is always the quit pipe */
756 pollfd[0].fd = thread_quit_pipe[0];
757
758 /* Apps socket */
759 pollfd[1].fd = apps_sock;
760 pollfd[1].events = POLLIN;
761
762 /* Notify all applications to register */
763 notify_apps(default_global_apps_pipe);
764
765 while (1) {
766 DBG("Accepting application registration");
767
768 /* Inifinite blocking call, waiting for transmission */
769 ret = poll(pollfd, 2, -1);
770 if (ret < 0) {
771 perror("poll apps thread");
772 goto error;
773 }
774
775 /* Thread quit pipe has been closed. Killing thread. */
776 if (pollfd[0].revents == POLLNVAL) {
777 goto error;
778 } else if (pollfd[1].revents == POLLERR) {
779 ERR("Apps socket poll error");
780 goto error;
781 }
782
783 sock = lttcomm_accept_unix_sock(apps_sock);
784 if (sock < 0) {
785 goto error;
786 }
787
788 /*
789 * Basic recv here to handle the very simple data
790 * that the libust send to register (reg_msg).
791 */
792 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
793 if (ret < 0) {
794 perror("recv");
795 continue;
796 }
797
798 /* Add application to the global traceable list */
799 if (reg_msg.reg == 1) {
800 /* Registering */
801 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
802 if (ret < 0) {
803 /* register_traceable_app only return an error with
804 * ENOMEM. At this point, we better stop everything.
805 */
806 goto error;
807 }
808 } else {
809 /* Unregistering */
810 unregister_traceable_app(reg_msg.pid);
811 }
812 }
813
814 error:
815 DBG("Apps thread dying");
816 if (apps_sock) {
817 close(apps_sock);
818 }
819 if (sock) {
820 close(sock);
821 }
822
823 unlink(apps_unix_sock_path);
824 return NULL;
825 }
826
827 /*
828 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
829 * exec or it will fails.
830 */
831 static int spawn_kconsumerd_thread(void)
832 {
833 int ret;
834
835 /* Setup semaphore */
836 sem_init(&kconsumerd_sem, 0, 0);
837
838 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
839 if (ret != 0) {
840 perror("pthread_create kconsumerd");
841 goto error;
842 }
843
844 /* Wait for the kconsumerd thread to be ready */
845 sem_wait(&kconsumerd_sem);
846
847 if (kconsumerd_pid == 0) {
848 ERR("Kconsumerd did not start");
849 goto error;
850 }
851
852 return 0;
853
854 error:
855 ret = LTTCOMM_KERN_CONSUMER_FAIL;
856 return ret;
857 }
858
859 /*
860 * Fork and exec a kernel consumer daemon (kconsumerd).
861 *
862 * Return pid if successful else -1.
863 */
864 static pid_t spawn_kconsumerd(void)
865 {
866 int ret;
867 pid_t pid;
868 const char *verbosity;
869
870 DBG("Spawning kconsumerd");
871
872 pid = fork();
873 if (pid == 0) {
874 /*
875 * Exec kconsumerd.
876 */
877 if (opt_verbose > 1) {
878 verbosity = "--verbose";
879 } else {
880 verbosity = "--quiet";
881 }
882 execl(INSTALL_BIN_PATH "/ltt-kconsumerd", "ltt-kconsumerd", verbosity, NULL);
883 if (errno != 0) {
884 perror("kernel start consumer exec");
885 }
886 exit(EXIT_FAILURE);
887 } else if (pid > 0) {
888 ret = pid;
889 goto error;
890 } else {
891 perror("kernel start consumer fork");
892 ret = -errno;
893 goto error;
894 }
895
896 error:
897 return ret;
898 }
899
900 /*
901 * Spawn the kconsumerd daemon and session daemon thread.
902 */
903 static int start_kconsumerd(void)
904 {
905 int ret;
906
907 pthread_mutex_lock(&kconsumerd_pid_mutex);
908 if (kconsumerd_pid != 0) {
909 pthread_mutex_unlock(&kconsumerd_pid_mutex);
910 goto end;
911 }
912
913 ret = spawn_kconsumerd();
914 if (ret < 0) {
915 ERR("Spawning kconsumerd failed");
916 ret = LTTCOMM_KERN_CONSUMER_FAIL;
917 pthread_mutex_unlock(&kconsumerd_pid_mutex);
918 goto error;
919 }
920
921 /* Setting up the global kconsumerd_pid */
922 kconsumerd_pid = ret;
923 pthread_mutex_unlock(&kconsumerd_pid_mutex);
924
925 DBG("Kconsumerd pid %d", ret);
926
927 DBG("Spawning kconsumerd thread");
928 ret = spawn_kconsumerd_thread();
929 if (ret < 0) {
930 ERR("Fatal error spawning kconsumerd thread");
931 goto error;
932 }
933
934 end:
935 return 0;
936
937 error:
938 return ret;
939 }
940
941 /*
942 * modprobe_kernel_modules
943 */
944 static int modprobe_kernel_modules(void)
945 {
946 int ret = 0, i = 0;
947 char modprobe[256];
948
949 while (kernel_modules_list[i] != NULL) {
950 ret = snprintf(modprobe, sizeof(modprobe), "/sbin/modprobe %s",
951 kernel_modules_list[i]);
952 if (ret < 0) {
953 perror("snprintf modprobe");
954 goto error;
955 }
956 ret = system(modprobe);
957 if (ret < 0) {
958 ERR("Unable to load module %s", kernel_modules_list[i]);
959 }
960 DBG("Modprobe successfully %s", kernel_modules_list[i]);
961 i++;
962 }
963
964 error:
965 return ret;
966 }
967
968 /*
969 * mount_debugfs
970 */
971 static int mount_debugfs(char *path)
972 {
973 int ret;
974 char *type = "debugfs";
975
976 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG);
977 if (ret < 0) {
978 goto error;
979 }
980
981 ret = mount(type, path, type, 0, NULL);
982 if (ret < 0) {
983 perror("mount debugfs");
984 goto error;
985 }
986
987 DBG("Mounted debugfs successfully at %s", path);
988
989 error:
990 return ret;
991 }
992
993 /*
994 * Setup necessary data for kernel tracer action.
995 */
996 static void init_kernel_tracer(void)
997 {
998 int ret;
999 char *proc_mounts = "/proc/mounts";
1000 char line[256];
1001 char *debugfs_path = NULL, *lttng_path;
1002 FILE *fp;
1003
1004 /* Detect debugfs */
1005 fp = fopen(proc_mounts, "r");
1006 if (fp == NULL) {
1007 ERR("Unable to probe %s", proc_mounts);
1008 goto error;
1009 }
1010
1011 while (fgets(line, sizeof(line), fp) != NULL) {
1012 if (strstr(line, "debugfs") != NULL) {
1013 /* Remove first string */
1014 strtok(line, " ");
1015 /* Dup string here so we can reuse line later on */
1016 debugfs_path = strdup(strtok(NULL, " "));
1017 DBG("Got debugfs path : %s", debugfs_path);
1018 break;
1019 }
1020 }
1021
1022 fclose(fp);
1023
1024 /* Mount debugfs if needded */
1025 if (debugfs_path == NULL) {
1026 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1027 if (ret < 0) {
1028 perror("asprintf debugfs path");
1029 goto error;
1030 }
1031 ret = mount_debugfs(debugfs_path);
1032 if (ret < 0) {
1033 goto error;
1034 }
1035 }
1036
1037 /* Modprobe lttng kernel modules */
1038 ret = modprobe_kernel_modules();
1039 if (ret < 0) {
1040 goto error;
1041 }
1042
1043 /* Setup lttng kernel path */
1044 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1045 if (ret < 0) {
1046 perror("asprintf lttng path");
1047 goto error;
1048 }
1049
1050 /* Open debugfs lttng */
1051 kernel_tracer_fd = open(lttng_path, O_RDWR);
1052 if (kernel_tracer_fd < 0) {
1053 DBG("Failed to open %s", lttng_path);
1054 goto error;
1055 }
1056
1057 free(lttng_path);
1058 free(debugfs_path);
1059 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1060 return;
1061
1062 error:
1063 if (lttng_path) {
1064 free(lttng_path);
1065 }
1066 if (debugfs_path) {
1067 free(debugfs_path);
1068 }
1069 WARN("No kernel tracer available");
1070 kernel_tracer_fd = 0;
1071 return;
1072 }
1073
1074 /*
1075 * Start tracing by creating trace directory and sending FDs to the kernel
1076 * consumer.
1077 */
1078 static int start_kernel_trace(struct ltt_kernel_session *session)
1079 {
1080 int ret = 0;
1081
1082 if (session->kconsumer_fds_sent == 0) {
1083 ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
1084 if (ret < 0) {
1085 ERR("Send kconsumerd fds failed");
1086 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1087 goto error;
1088 }
1089
1090 session->kconsumer_fds_sent = 1;
1091 }
1092
1093 error:
1094 return ret;
1095 }
1096
1097 /*
1098 * Notify kernel thread to update it's pollfd.
1099 */
1100 static int notify_kernel_pollfd(void)
1101 {
1102 int ret;
1103
1104 /* Inform kernel thread of the new kernel channel */
1105 ret = write(kernel_poll_pipe[1], "!", 1);
1106 if (ret < 0) {
1107 perror("write kernel poll pipe");
1108 }
1109
1110 return ret;
1111 }
1112
1113 /*
1114 * Allocate a channel structure and fill it.
1115 */
1116 static struct lttng_channel *init_default_channel(char *name)
1117 {
1118 struct lttng_channel *chan;
1119
1120 chan = malloc(sizeof(struct lttng_channel));
1121 if (chan == NULL) {
1122 perror("init channel malloc");
1123 goto error;
1124 }
1125
1126 if (snprintf(chan->name, NAME_MAX, "%s", name) < 0) {
1127 perror("snprintf channel name");
1128 return NULL;
1129 }
1130
1131 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1132 chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
1133 chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
1134 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1135 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1136 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1137
1138 error:
1139 return chan;
1140 }
1141
1142 /*
1143 * Create a kernel tracer session then create the default channel.
1144 */
1145 static int create_kernel_session(struct ltt_session *session)
1146 {
1147 int ret;
1148
1149 DBG("Creating kernel session");
1150
1151 ret = kernel_create_session(session, kernel_tracer_fd);
1152 if (ret < 0) {
1153 ret = LTTCOMM_KERN_SESS_FAIL;
1154 goto error;
1155 }
1156
1157 ret = mkdir_recursive(session->path, S_IRWXU | S_IRWXG );
1158 if (ret < 0) {
1159 if (ret != EEXIST) {
1160 ERR("Trace directory creation error");
1161 goto error;
1162 }
1163 }
1164
1165 error:
1166 return ret;
1167 }
1168
1169 /*
1170 * Using the session list, filled a lttng_session array to send back to the
1171 * client for session listing.
1172 *
1173 * The session list lock MUST be acquired before calling this function. Use
1174 * lock_session_list() and unlock_session_list().
1175 */
1176 static void list_lttng_sessions(struct lttng_session *sessions)
1177 {
1178 int i = 0;
1179 struct ltt_session *session;
1180
1181 DBG("Getting all available session");
1182 /*
1183 * Iterate over session list and append data after the control struct in
1184 * the buffer.
1185 */
1186 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1187 strncpy(sessions[i].path, session->path, PATH_MAX);
1188 strncpy(sessions[i].name, session->name, NAME_MAX);
1189 i++;
1190 }
1191 }
1192
1193 /*
1194 * Fill lttng_channel array of all channels.
1195 */
1196 static void list_lttng_channels(struct ltt_session *session,
1197 struct lttng_channel *channels)
1198 {
1199 int i = 0;
1200 struct ltt_kernel_channel *kchan;
1201
1202 DBG("Listing channels for session %s", session->name);
1203
1204 /* Kernel channels */
1205 if (session->kernel_session != NULL) {
1206 cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) {
1207 /* Copy lttng_channel struct to array */
1208 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1209 channels[i].enabled = kchan->enabled;
1210 i++;
1211 }
1212 }
1213
1214 /* TODO: Missing UST listing */
1215 }
1216
1217 /*
1218 * Fill lttng_event array of all events in the channel.
1219 */
1220 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1221 struct lttng_event *events)
1222 {
1223 /*
1224 * TODO: This is ONLY kernel. Need UST support.
1225 */
1226 int i = 0;
1227 struct ltt_kernel_event *event;
1228
1229 DBG("Listing events for channel %s", kchan->channel->name);
1230
1231 /* Kernel channels */
1232 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1233 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1234 events[i].enabled = event->enabled;
1235 switch (event->event->instrumentation) {
1236 case LTTNG_KERNEL_TRACEPOINT:
1237 events[i].type = LTTNG_EVENT_TRACEPOINT;
1238 break;
1239 case LTTNG_KERNEL_KPROBE:
1240 case LTTNG_KERNEL_KRETPROBE:
1241 events[i].type = LTTNG_EVENT_PROBE;
1242 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1243 sizeof(struct lttng_kernel_kprobe));
1244 break;
1245 case LTTNG_KERNEL_FUNCTION:
1246 events[i].type = LTTNG_EVENT_FUNCTION;
1247 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1248 sizeof(struct lttng_kernel_function));
1249 break;
1250 }
1251 i++;
1252 }
1253 }
1254
1255 /*
1256 * Process the command requested by the lttng client within the command
1257 * context structure. This function make sure that the return structure (llm)
1258 * is set and ready for transmission before returning.
1259 *
1260 * Return any error encountered or 0 for success.
1261 */
1262 static int process_client_msg(struct command_ctx *cmd_ctx)
1263 {
1264 int ret = LTTCOMM_OK;
1265
1266 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1267
1268 /* Listing commands don't need a session */
1269 switch (cmd_ctx->lsm->cmd_type) {
1270 case LTTNG_CREATE_SESSION:
1271 case LTTNG_LIST_SESSIONS:
1272 case LTTNG_KERNEL_LIST_EVENTS:
1273 break;
1274 default:
1275 DBG("Getting session %s by name", cmd_ctx->lsm->session_name);
1276 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name);
1277 if (cmd_ctx->session == NULL) {
1278 /* If session name not found */
1279 if (cmd_ctx->lsm->session_name != NULL) {
1280 ret = LTTCOMM_SESS_NOT_FOUND;
1281 } else { /* If no session name specified */
1282 ret = LTTCOMM_SELECT_SESS;
1283 }
1284 goto error;
1285 } else {
1286 /* Acquire lock for the session */
1287 lock_session(cmd_ctx->session);
1288 }
1289 break;
1290 }
1291
1292 /*
1293 * Check kernel command for kernel session.
1294 */
1295 switch (cmd_ctx->lsm->cmd_type) {
1296 case LTTNG_KERNEL_ADD_CONTEXT:
1297 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1298 case LTTNG_KERNEL_DISABLE_CHANNEL:
1299 case LTTNG_KERNEL_DISABLE_EVENT:
1300 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1301 case LTTNG_KERNEL_ENABLE_CHANNEL:
1302 case LTTNG_KERNEL_ENABLE_EVENT:
1303 case LTTNG_KERNEL_LIST_EVENTS:
1304 /* Kernel tracer check */
1305 if (kernel_tracer_fd == 0) {
1306 init_kernel_tracer();
1307 if (kernel_tracer_fd == 0) {
1308 ret = LTTCOMM_KERN_NA;
1309 goto error;
1310 }
1311 }
1312
1313 /* Need a session for kernel command */
1314 if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS &&
1315 cmd_ctx->session->kernel_session == NULL) {
1316
1317 ret = create_kernel_session(cmd_ctx->session);
1318 if (ret < 0) {
1319 ret = LTTCOMM_KERN_SESS_FAIL;
1320 goto error;
1321 }
1322
1323 /* Start the kernel consumer daemon */
1324 if (kconsumerd_pid == 0) {
1325 ret = start_kconsumerd();
1326 if (ret < 0) {
1327 goto error;
1328 }
1329 }
1330 }
1331 }
1332
1333 #ifdef DISABLED
1334 /* Connect to ust apps if available pid */
1335 if (cmd_ctx->lsm->pid > 0) {
1336 /* Connect to app using ustctl API */
1337 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
1338 if (cmd_ctx->ust_sock < 0) {
1339 ret = LTTCOMM_NO_TRACEABLE;
1340 goto error;
1341 }
1342 }
1343 #endif /* DISABLED */
1344
1345 /* Process by command type */
1346 switch (cmd_ctx->lsm->cmd_type) {
1347 case LTTNG_KERNEL_ADD_CONTEXT:
1348 {
1349 int found = 0, no_event = 0;
1350 struct ltt_kernel_channel *chan;
1351 struct ltt_kernel_event *event;
1352 struct lttng_kernel_context ctx;
1353
1354 /* Setup lttng message with no payload */
1355 ret = setup_lttng_msg(cmd_ctx, 0);
1356 if (ret < 0) {
1357 goto setup_error;
1358 }
1359
1360 /* Check if event name is given */
1361 if (strlen(cmd_ctx->lsm->u.context.event_name) == 0) {
1362 no_event = 1;
1363 }
1364
1365 /* Create Kernel context */
1366 ctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1367 ctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1368 ctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1369 strncpy(ctx.u.perf_counter.name,
1370 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1371 sizeof(ctx.u.perf_counter.name));
1372
1373 if (strlen(cmd_ctx->lsm->u.context.channel_name) == 0) {
1374 /* Go over all channels */
1375 DBG("Adding context to all channels");
1376 cds_list_for_each_entry(chan,
1377 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1378 if (no_event) {
1379 ret = kernel_add_channel_context(chan, &ctx);
1380 if (ret < 0) {
1381 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1382 goto error;
1383 }
1384 } else {
1385 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1386 if (event != NULL) {
1387 ret = kernel_add_event_context(event, &ctx);
1388 if (ret < 0) {
1389 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1390 goto error;
1391 }
1392 found = 1;
1393 break;
1394 }
1395 }
1396 }
1397 } else {
1398 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.context.channel_name,
1399 cmd_ctx->session->kernel_session);
1400 if (chan == NULL) {
1401 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1402 goto error;
1403 }
1404
1405 if (no_event) {
1406 ret = kernel_add_channel_context(chan, &ctx);
1407 if (ret < 0) {
1408 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1409 goto error;
1410 }
1411 } else {
1412 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1413 if (event != NULL) {
1414 ret = kernel_add_event_context(event, &ctx);
1415 if (ret < 0) {
1416 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1417 goto error;
1418 }
1419 }
1420 }
1421 }
1422
1423 if (!found && !no_event) {
1424 ret = LTTCOMM_NO_EVENT;
1425 goto error;
1426 }
1427
1428 ret = LTTCOMM_OK;
1429 break;
1430 }
1431 case LTTNG_KERNEL_DISABLE_CHANNEL:
1432 {
1433 struct ltt_kernel_channel *chan;
1434
1435 /* Setup lttng message with no payload */
1436 ret = setup_lttng_msg(cmd_ctx, 0);
1437 if (ret < 0) {
1438 goto setup_error;
1439 }
1440
1441 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1442 cmd_ctx->session->kernel_session);
1443 if (chan == NULL) {
1444 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1445 goto error;
1446 } else if (chan->enabled == 1) {
1447 ret = kernel_disable_channel(chan);
1448 if (ret < 0) {
1449 if (ret != EEXIST) {
1450 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1451 }
1452 goto error;
1453 }
1454 }
1455
1456 kernel_wait_quiescent(kernel_tracer_fd);
1457 ret = LTTCOMM_OK;
1458 break;
1459 }
1460 case LTTNG_KERNEL_DISABLE_EVENT:
1461 {
1462 struct ltt_kernel_channel *chan;
1463 struct ltt_kernel_event *ev;
1464
1465 /* Setup lttng message with no payload */
1466 ret = setup_lttng_msg(cmd_ctx, 0);
1467 if (ret < 0) {
1468 goto setup_error;
1469 }
1470
1471 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1472 cmd_ctx->session->kernel_session);
1473 if (chan == NULL) {
1474 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1475 goto error;
1476 }
1477
1478 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, chan);
1479 if (ev != NULL) {
1480 DBG("Disabling kernel event %s for channel %s.",
1481 cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name);
1482 ret = kernel_disable_event(ev);
1483 if (ret < 0) {
1484 ret = LTTCOMM_KERN_ENABLE_FAIL;
1485 goto error;
1486 }
1487 }
1488
1489 kernel_wait_quiescent(kernel_tracer_fd);
1490 ret = LTTCOMM_OK;
1491 break;
1492 }
1493 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1494 {
1495 struct ltt_kernel_channel *chan;
1496 struct ltt_kernel_event *ev;
1497
1498 /* Setup lttng message with no payload */
1499 ret = setup_lttng_msg(cmd_ctx, 0);
1500 if (ret < 0) {
1501 goto setup_error;
1502 }
1503
1504 DBG("Disabling all enabled kernel events");
1505
1506 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1507 cmd_ctx->session->kernel_session);
1508 if (chan == NULL) {
1509 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1510 goto error;
1511 }
1512
1513 /* For each event in the kernel session */
1514 cds_list_for_each_entry(ev, &chan->events_list.head, list) {
1515 DBG("Disabling kernel event %s for channel %s.",
1516 ev->event->name, cmd_ctx->lsm->u.disable.channel_name);
1517 ret = kernel_disable_event(ev);
1518 if (ret < 0) {
1519 continue;
1520 }
1521 }
1522
1523 /* Quiescent wait after event disable */
1524 kernel_wait_quiescent(kernel_tracer_fd);
1525 ret = LTTCOMM_OK;
1526 break;
1527 }
1528 case LTTNG_KERNEL_ENABLE_CHANNEL:
1529 {
1530 struct ltt_kernel_channel *chan;
1531
1532 /* Setup lttng message with no payload */
1533 ret = setup_lttng_msg(cmd_ctx, 0);
1534 if (ret < 0) {
1535 goto setup_error;
1536 }
1537
1538 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1539 cmd_ctx->session->kernel_session);
1540 if (chan == NULL) {
1541 /* Channel not found, creating it */
1542 DBG("Creating kernel channel");
1543
1544 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1545 &cmd_ctx->lsm->u.channel.chan, cmd_ctx->session->path);
1546 if (ret < 0) {
1547 ret = LTTCOMM_KERN_CHAN_FAIL;
1548 goto error;
1549 }
1550
1551 /* Notify kernel thread that there is a new channel */
1552 ret = notify_kernel_pollfd();
1553 if (ret < 0) {
1554 ret = LTTCOMM_FATAL;
1555 goto error;
1556 }
1557 } else if (chan->enabled == 0) {
1558 ret = kernel_enable_channel(chan);
1559 if (ret < 0) {
1560 if (ret != EEXIST) {
1561 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1562 }
1563 goto error;
1564 }
1565 }
1566
1567 kernel_wait_quiescent(kernel_tracer_fd);
1568 ret = LTTCOMM_OK;
1569 break;
1570 }
1571 case LTTNG_KERNEL_ENABLE_EVENT:
1572 {
1573 char *channel_name;
1574 struct ltt_kernel_channel *kchan;
1575 struct ltt_kernel_event *ev;
1576 struct lttng_channel *chan;
1577
1578 /* Setup lttng message with no payload */
1579 ret = setup_lttng_msg(cmd_ctx, 0);
1580 if (ret < 0) {
1581 goto setup_error;
1582 }
1583
1584 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1585
1586 do {
1587 kchan = get_kernel_channel_by_name(channel_name,
1588 cmd_ctx->session->kernel_session);
1589 if (kchan == NULL) {
1590 DBG("Channel not found. Creating channel %s", channel_name);
1591
1592 chan = init_default_channel(channel_name);
1593 if (chan == NULL) {
1594 ret = LTTCOMM_FATAL;
1595 goto error;
1596 }
1597
1598 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1599 chan, cmd_ctx->session->path);
1600 if (ret < 0) {
1601 ret = LTTCOMM_KERN_CHAN_FAIL;
1602 goto error;
1603 }
1604 }
1605 } while (kchan == NULL);
1606
1607 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
1608 if (ev == NULL) {
1609 DBG("Creating kernel event %s for channel %s.",
1610 cmd_ctx->lsm->u.enable.event.name, channel_name);
1611 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
1612 } else {
1613 DBG("Enabling kernel event %s for channel %s.",
1614 cmd_ctx->lsm->u.enable.event.name, channel_name);
1615 ret = kernel_enable_event(ev);
1616 if (ret == -EEXIST) {
1617 ret = LTTCOMM_KERN_EVENT_EXIST;
1618 goto error;
1619 }
1620 }
1621
1622 if (ret < 0) {
1623 ret = LTTCOMM_KERN_ENABLE_FAIL;
1624 goto error;
1625 }
1626
1627 kernel_wait_quiescent(kernel_tracer_fd);
1628 ret = LTTCOMM_OK;
1629 break;
1630 }
1631 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1632 {
1633 int size, i;
1634 char *channel_name;
1635 struct ltt_kernel_channel *kchan;
1636 struct ltt_kernel_event *ev;
1637 struct lttng_event *event_list;
1638 struct lttng_channel *chan;
1639
1640 /* Setup lttng message with no payload */
1641 ret = setup_lttng_msg(cmd_ctx, 0);
1642 if (ret < 0) {
1643 goto setup_error;
1644 }
1645
1646 DBG("Enabling all kernel event");
1647
1648 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1649
1650 do {
1651 kchan = get_kernel_channel_by_name(channel_name,
1652 cmd_ctx->session->kernel_session);
1653 if (kchan == NULL) {
1654 DBG("Channel not found. Creating channel %s", channel_name);
1655
1656 chan = init_default_channel(channel_name);
1657 if (chan == NULL) {
1658 ret = LTTCOMM_FATAL;
1659 goto error;
1660 }
1661
1662 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1663 chan, cmd_ctx->session->path);
1664 if (ret < 0) {
1665 ret = LTTCOMM_KERN_CHAN_FAIL;
1666 goto error;
1667 }
1668 }
1669 } while (kchan == NULL);
1670
1671 /* For each event in the kernel session */
1672 cds_list_for_each_entry(ev, &kchan->events_list.head, list) {
1673 DBG("Enabling kernel event %s for channel %s.",
1674 ev->event->name, channel_name);
1675 ret = kernel_enable_event(ev);
1676 if (ret < 0) {
1677 continue;
1678 }
1679 }
1680
1681 size = kernel_list_events(kernel_tracer_fd, &event_list);
1682 if (size < 0) {
1683 ret = LTTCOMM_KERN_LIST_FAIL;
1684 goto error;
1685 }
1686
1687 for (i = 0; i < size; i++) {
1688 ev = get_kernel_event_by_name(event_list[i].name, kchan);
1689 if (ev == NULL) {
1690 /* Default event type for enable all */
1691 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
1692 /* Enable each single tracepoint event */
1693 ret = kernel_create_event(&event_list[i], kchan);
1694 if (ret < 0) {
1695 /* Ignore error here and continue */
1696 }
1697 }
1698 }
1699
1700 free(event_list);
1701
1702 /* Quiescent wait after event enable */
1703 kernel_wait_quiescent(kernel_tracer_fd);
1704 ret = LTTCOMM_OK;
1705 break;
1706 }
1707 case LTTNG_KERNEL_LIST_EVENTS:
1708 {
1709 struct lttng_event *events;
1710 ssize_t size = 0;
1711
1712 DBG("Listing kernel events");
1713
1714 size = kernel_list_events(kernel_tracer_fd, &events);
1715 if (size < 0) {
1716 ret = LTTCOMM_KERN_LIST_FAIL;
1717 goto error;
1718 }
1719
1720 /*
1721 * Setup lttng message with payload size set to the event list size in
1722 * bytes and then copy list into the llm payload.
1723 */
1724 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * size);
1725 if (ret < 0) {
1726 goto setup_error;
1727 }
1728
1729 /* Copy event list into message payload */
1730 memcpy(cmd_ctx->llm->payload, events,
1731 sizeof(struct lttng_event) * size);
1732
1733 free(events);
1734
1735 ret = LTTCOMM_OK;
1736 break;
1737 }
1738 case LTTNG_START_TRACE:
1739 {
1740 struct ltt_kernel_channel *chan;
1741
1742 /* Setup lttng message with no payload */
1743 ret = setup_lttng_msg(cmd_ctx, 0);
1744 if (ret < 0) {
1745 goto setup_error;
1746 }
1747
1748 /* Kernel tracing */
1749 if (cmd_ctx->session->kernel_session != NULL) {
1750 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1751 DBG("Open kernel metadata");
1752 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1753 cmd_ctx->session->path);
1754 if (ret < 0) {
1755 ret = LTTCOMM_KERN_META_FAIL;
1756 goto error;
1757 }
1758 }
1759
1760 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1761 DBG("Opening kernel metadata stream");
1762 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1763 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1764 if (ret < 0) {
1765 ERR("Kernel create metadata stream failed");
1766 ret = LTTCOMM_KERN_STREAM_FAIL;
1767 goto error;
1768 }
1769 }
1770 }
1771
1772 /* For each channel */
1773 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1774 if (chan->stream_count == 0) {
1775 ret = kernel_open_channel_stream(chan);
1776 if (ret < 0) {
1777 ERR("Kernel create channel stream failed");
1778 ret = LTTCOMM_KERN_STREAM_FAIL;
1779 goto error;
1780 }
1781 /* Update the stream global counter */
1782 cmd_ctx->session->kernel_session->stream_count_global += ret;
1783 }
1784 }
1785
1786 DBG("Start kernel tracing");
1787 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1788 if (ret < 0) {
1789 ERR("Kernel start session failed");
1790 ret = LTTCOMM_KERN_START_FAIL;
1791 goto error;
1792 }
1793
1794 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1795 if (ret < 0) {
1796 ret = LTTCOMM_KERN_START_FAIL;
1797 goto error;
1798 }
1799
1800 /* Quiescent wait after starting trace */
1801 kernel_wait_quiescent(kernel_tracer_fd);
1802 }
1803
1804 /* TODO: Start all UST traces */
1805
1806 ret = LTTCOMM_OK;
1807 break;
1808 }
1809 case LTTNG_STOP_TRACE:
1810 {
1811 struct ltt_kernel_channel *chan;
1812 /* Setup lttng message with no payload */
1813 ret = setup_lttng_msg(cmd_ctx, 0);
1814 if (ret < 0) {
1815 goto setup_error;
1816 }
1817
1818 /* Kernel tracer */
1819 if (cmd_ctx->session->kernel_session != NULL) {
1820 DBG("Stop kernel tracing");
1821
1822 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
1823 if (ret < 0) {
1824 ERR("Kernel metadata flush failed");
1825 }
1826
1827 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1828 ret = kernel_flush_buffer(chan);
1829 if (ret < 0) {
1830 ERR("Kernel flush buffer error");
1831 }
1832 }
1833
1834 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
1835 if (ret < 0) {
1836 ERR("Kernel stop session failed");
1837 ret = LTTCOMM_KERN_STOP_FAIL;
1838 goto error;
1839 }
1840
1841 /* Quiescent wait after stopping trace */
1842 kernel_wait_quiescent(kernel_tracer_fd);
1843 }
1844
1845 /* TODO : User-space tracer */
1846
1847 ret = LTTCOMM_OK;
1848 break;
1849 }
1850 case LTTNG_CREATE_SESSION:
1851 {
1852 /* Setup lttng message with no payload */
1853 ret = setup_lttng_msg(cmd_ctx, 0);
1854 if (ret < 0) {
1855 goto setup_error;
1856 }
1857
1858 ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path);
1859 if (ret < 0) {
1860 if (ret == -EEXIST) {
1861 ret = LTTCOMM_EXIST_SESS;
1862 } else {
1863 ret = LTTCOMM_FATAL;
1864 }
1865 goto error;
1866 }
1867
1868 ret = LTTCOMM_OK;
1869 break;
1870 }
1871 case LTTNG_DESTROY_SESSION:
1872 {
1873 /* Setup lttng message with no payload */
1874 ret = setup_lttng_msg(cmd_ctx, 0);
1875 if (ret < 0) {
1876 goto setup_error;
1877 }
1878
1879 /* Clean kernel session teardown */
1880 teardown_kernel_session(cmd_ctx->session);
1881
1882 ret = destroy_session(cmd_ctx->lsm->session_name);
1883 if (ret < 0) {
1884 ret = LTTCOMM_FATAL;
1885 goto error;
1886 }
1887
1888 /*
1889 * Must notify the kernel thread here to update it's pollfd in order to
1890 * remove the channel(s)' fd just destroyed.
1891 */
1892 ret = notify_kernel_pollfd();
1893 if (ret < 0) {
1894 ret = LTTCOMM_FATAL;
1895 goto error;
1896 }
1897
1898 ret = LTTCOMM_OK;
1899 break;
1900 }
1901 /*
1902 case UST_CREATE_TRACE:
1903 {
1904 ret = setup_lttng_msg(cmd_ctx, 0);
1905 if (ret < 0) {
1906 goto setup_error;
1907 }
1908
1909 ret = ust_create_trace(cmd_ctx);
1910 if (ret < 0) {
1911 goto error;
1912 }
1913 break;
1914 }
1915 case UST_START_TRACE:
1916 {
1917 ret = setup_lttng_msg(cmd_ctx, 0);
1918 if (ret < 0) {
1919 goto setup_error;
1920 }
1921
1922 ret = ust_start_trace(cmd_ctx);
1923 if (ret < 0) {
1924 goto setup_error;
1925 }
1926 break;
1927 }
1928 case UST_STOP_TRACE:
1929 {
1930 ret = setup_lttng_msg(cmd_ctx, 0);
1931 if (ret < 0) {
1932 goto setup_error;
1933 }
1934
1935 ret = ust_stop_trace(cmd_ctx);
1936 if (ret < 0) {
1937 goto setup_error;
1938 }
1939 break;
1940 }
1941 */
1942 case LTTNG_LIST_DOMAINS:
1943 {
1944 size_t nb_dom;
1945
1946 if (cmd_ctx->session->kernel_session != NULL) {
1947 nb_dom++;
1948 }
1949
1950 nb_dom += cmd_ctx->session->ust_trace_count;
1951
1952 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_domain) * nb_dom);
1953 if (ret < 0) {
1954 goto setup_error;
1955 }
1956
1957 ((struct lttng_domain *)(cmd_ctx->llm->payload))[0].type =
1958 LTTNG_DOMAIN_KERNEL;
1959
1960 /* TODO: User-space tracer domain support */
1961 ret = LTTCOMM_OK;
1962 break;
1963 }
1964 case LTTNG_LIST_CHANNELS:
1965 {
1966 /*
1967 * TODO: Only kernel channels are listed here. UST listing
1968 * is needed on lttng-ust 2.0 release.
1969 */
1970 size_t nb_chan = 0;
1971 if (cmd_ctx->session->kernel_session != NULL) {
1972 nb_chan += cmd_ctx->session->kernel_session->channel_count;
1973 }
1974
1975 ret = setup_lttng_msg(cmd_ctx,
1976 sizeof(struct lttng_channel) * nb_chan);
1977 if (ret < 0) {
1978 goto setup_error;
1979 }
1980
1981 list_lttng_channels(cmd_ctx->session,
1982 (struct lttng_channel *)(cmd_ctx->llm->payload));
1983
1984 ret = LTTCOMM_OK;
1985 break;
1986 }
1987 case LTTNG_LIST_EVENTS:
1988 {
1989 /*
1990 * TODO: Only kernel events are listed here. UST listing
1991 * is needed on lttng-ust 2.0 release.
1992 */
1993 size_t nb_event = 0;
1994 struct ltt_kernel_channel *kchan = NULL;
1995
1996 if (cmd_ctx->session->kernel_session != NULL) {
1997 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.list.channel_name,
1998 cmd_ctx->session->kernel_session);
1999 if (kchan == NULL) {
2000 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2001 goto error;
2002 }
2003 nb_event += kchan->event_count;
2004 }
2005
2006 ret = setup_lttng_msg(cmd_ctx,
2007 sizeof(struct lttng_event) * nb_event);
2008 if (ret < 0) {
2009 goto setup_error;
2010 }
2011
2012 DBG("Listing events (%ld events)", nb_event);
2013
2014 list_lttng_events(kchan,
2015 (struct lttng_event *)(cmd_ctx->llm->payload));
2016
2017 ret = LTTCOMM_OK;
2018 break;
2019 }
2020 case LTTNG_LIST_SESSIONS:
2021 {
2022 lock_session_list();
2023
2024 if (session_list_ptr->count == 0) {
2025 ret = LTTCOMM_NO_SESSION;
2026 unlock_session_list();
2027 goto error;
2028 }
2029
2030 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
2031 session_list_ptr->count);
2032 if (ret < 0) {
2033 unlock_session_list();
2034 goto setup_error;
2035 }
2036
2037 /* Filled the session array */
2038 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
2039
2040 unlock_session_list();
2041
2042 ret = LTTCOMM_OK;
2043 break;
2044 }
2045 default:
2046 /* Undefined command */
2047 ret = setup_lttng_msg(cmd_ctx, 0);
2048 if (ret < 0) {
2049 goto setup_error;
2050 }
2051
2052 ret = LTTCOMM_UND;
2053 break;
2054 }
2055
2056 /* Set return code */
2057 cmd_ctx->llm->ret_code = ret;
2058
2059 if (cmd_ctx->session) {
2060 unlock_session(cmd_ctx->session);
2061 }
2062
2063 return ret;
2064
2065 error:
2066 if (cmd_ctx->llm == NULL) {
2067 DBG("Missing llm structure. Allocating one.");
2068 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2069 goto setup_error;
2070 }
2071 }
2072 /* Notify client of error */
2073 cmd_ctx->llm->ret_code = ret;
2074
2075 setup_error:
2076 if (cmd_ctx->session) {
2077 unlock_session(cmd_ctx->session);
2078 }
2079 return ret;
2080 }
2081
2082 /*
2083 * This thread manage all clients request using the unix client socket for
2084 * communication.
2085 */
2086 static void *thread_manage_clients(void *data)
2087 {
2088 int sock = 0, ret;
2089 struct command_ctx *cmd_ctx = NULL;
2090 struct pollfd pollfd[2];
2091
2092 DBG("[thread] Manage client started");
2093
2094 ret = lttcomm_listen_unix_sock(client_sock);
2095 if (ret < 0) {
2096 goto error;
2097 }
2098
2099 /* First fd is always the quit pipe */
2100 pollfd[0].fd = thread_quit_pipe[0];
2101
2102 /* Apps socket */
2103 pollfd[1].fd = client_sock;
2104 pollfd[1].events = POLLIN;
2105
2106 /* Notify parent pid that we are ready
2107 * to accept command for client side.
2108 */
2109 if (opt_sig_parent) {
2110 kill(ppid, SIGCHLD);
2111 }
2112
2113 while (1) {
2114 DBG("Accepting client command ...");
2115
2116 /* Inifinite blocking call, waiting for transmission */
2117 ret = poll(pollfd, 2, -1);
2118 if (ret < 0) {
2119 perror("poll client thread");
2120 goto error;
2121 }
2122
2123 /* Thread quit pipe has been closed. Killing thread. */
2124 if (pollfd[0].revents == POLLNVAL) {
2125 goto error;
2126 } else if (pollfd[1].revents == POLLERR) {
2127 ERR("Client socket poll error");
2128 goto error;
2129 }
2130
2131 sock = lttcomm_accept_unix_sock(client_sock);
2132 if (sock < 0) {
2133 goto error;
2134 }
2135
2136 /* Allocate context command to process the client request */
2137 cmd_ctx = malloc(sizeof(struct command_ctx));
2138
2139 /* Allocate data buffer for reception */
2140 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2141 cmd_ctx->llm = NULL;
2142 cmd_ctx->session = NULL;
2143
2144 /*
2145 * Data is received from the lttng client. The struct
2146 * lttcomm_session_msg (lsm) contains the command and data request of
2147 * the client.
2148 */
2149 DBG("Receiving data from client ...");
2150 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2151 if (ret <= 0) {
2152 continue;
2153 }
2154
2155 // TODO: Validate cmd_ctx including sanity check for security purpose.
2156
2157 /*
2158 * This function dispatch the work to the kernel or userspace tracer
2159 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2160 * informations for the client. The command context struct contains
2161 * everything this function may needs.
2162 */
2163 ret = process_client_msg(cmd_ctx);
2164 if (ret < 0) {
2165 /* TODO: Inform client somehow of the fatal error. At this point,
2166 * ret < 0 means that a malloc failed (ENOMEM). */
2167 /* Error detected but still accept command */
2168 clean_command_ctx(&cmd_ctx);
2169 continue;
2170 }
2171
2172 DBG("Sending response (size: %d, retcode: %d)",
2173 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2174 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2175 if (ret < 0) {
2176 ERR("Failed to send data back to client");
2177 }
2178
2179 clean_command_ctx(&cmd_ctx);
2180
2181 /* End of transmission */
2182 close(sock);
2183 }
2184
2185 error:
2186 DBG("Client thread dying");
2187 if (client_sock) {
2188 close(client_sock);
2189 }
2190 if (sock) {
2191 close(sock);
2192 }
2193
2194 unlink(client_unix_sock_path);
2195
2196 clean_command_ctx(&cmd_ctx);
2197 return NULL;
2198 }
2199
2200
2201 /*
2202 * usage function on stderr
2203 */
2204 static void usage(void)
2205 {
2206 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2207 fprintf(stderr, " -h, --help Display this usage.\n");
2208 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2209 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2210 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2211 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2212 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2213 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2214 fprintf(stderr, " -V, --version Show version number.\n");
2215 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2216 fprintf(stderr, " -q, --quiet No output at all.\n");
2217 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2218 }
2219
2220 /*
2221 * daemon argument parsing
2222 */
2223 static int parse_args(int argc, char **argv)
2224 {
2225 int c;
2226
2227 static struct option long_options[] = {
2228 { "client-sock", 1, 0, 'c' },
2229 { "apps-sock", 1, 0, 'a' },
2230 { "kconsumerd-cmd-sock", 1, 0, 0 },
2231 { "kconsumerd-err-sock", 1, 0, 0 },
2232 { "daemonize", 0, 0, 'd' },
2233 { "sig-parent", 0, 0, 'S' },
2234 { "help", 0, 0, 'h' },
2235 { "group", 1, 0, 'g' },
2236 { "version", 0, 0, 'V' },
2237 { "quiet", 0, 0, 'q' },
2238 { "verbose", 0, 0, 'v' },
2239 { NULL, 0, 0, 0 }
2240 };
2241
2242 while (1) {
2243 int option_index = 0;
2244 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
2245 if (c == -1) {
2246 break;
2247 }
2248
2249 switch (c) {
2250 case 0:
2251 fprintf(stderr, "option %s", long_options[option_index].name);
2252 if (optarg) {
2253 fprintf(stderr, " with arg %s\n", optarg);
2254 }
2255 break;
2256 case 'c':
2257 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2258 break;
2259 case 'a':
2260 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2261 break;
2262 case 'd':
2263 opt_daemon = 1;
2264 break;
2265 case 'g':
2266 opt_tracing_group = strdup(optarg);
2267 break;
2268 case 'h':
2269 usage();
2270 exit(EXIT_FAILURE);
2271 case 'V':
2272 fprintf(stdout, "%s\n", VERSION);
2273 exit(EXIT_SUCCESS);
2274 case 'S':
2275 opt_sig_parent = 1;
2276 break;
2277 case 'E':
2278 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2279 break;
2280 case 'C':
2281 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2282 break;
2283 case 'q':
2284 opt_quiet = 1;
2285 break;
2286 case 'v':
2287 /* Verbose level can increase using multiple -v */
2288 opt_verbose += 1;
2289 break;
2290 default:
2291 /* Unknown option or other error.
2292 * Error is printed by getopt, just return */
2293 return -1;
2294 }
2295 }
2296
2297 return 0;
2298 }
2299
2300 /*
2301 * Creates the two needed socket by the daemon.
2302 * apps_sock - The communication socket for all UST apps.
2303 * client_sock - The communication of the cli tool (lttng).
2304 */
2305 static int init_daemon_socket()
2306 {
2307 int ret = 0;
2308 mode_t old_umask;
2309
2310 old_umask = umask(0);
2311
2312 /* Create client tool unix socket */
2313 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2314 if (client_sock < 0) {
2315 ERR("Create unix sock failed: %s", client_unix_sock_path);
2316 ret = -1;
2317 goto end;
2318 }
2319
2320 /* File permission MUST be 660 */
2321 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2322 if (ret < 0) {
2323 ERR("Set file permissions failed: %s", client_unix_sock_path);
2324 perror("chmod");
2325 goto end;
2326 }
2327
2328 /* Create the application unix socket */
2329 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2330 if (apps_sock < 0) {
2331 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2332 ret = -1;
2333 goto end;
2334 }
2335
2336 /* File permission MUST be 666 */
2337 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2338 if (ret < 0) {
2339 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2340 perror("chmod");
2341 goto end;
2342 }
2343
2344 end:
2345 umask(old_umask);
2346 return ret;
2347 }
2348
2349 /*
2350 * Check if the global socket is available. If yes, error is returned.
2351 */
2352 static int check_existing_daemon()
2353 {
2354 int ret;
2355
2356 ret = access(client_unix_sock_path, F_OK);
2357 if (ret == 0) {
2358 ret = access(apps_unix_sock_path, F_OK);
2359 }
2360
2361 return ret;
2362 }
2363
2364 /*
2365 * Set the tracing group gid onto the client socket.
2366 *
2367 * Race window between mkdir and chown is OK because we are going from more
2368 * permissive (root.root) to les permissive (root.tracing).
2369 */
2370 static int set_permissions(void)
2371 {
2372 int ret;
2373 struct group *grp;
2374
2375 /* Decide which group name to use */
2376 (opt_tracing_group != NULL) ?
2377 (grp = getgrnam(opt_tracing_group)) :
2378 (grp = getgrnam(default_tracing_group));
2379
2380 if (grp == NULL) {
2381 if (is_root) {
2382 WARN("No tracing group detected");
2383 ret = 0;
2384 } else {
2385 ERR("Missing tracing group. Aborting execution.");
2386 ret = -1;
2387 }
2388 goto end;
2389 }
2390
2391 /* Set lttng run dir */
2392 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
2393 if (ret < 0) {
2394 ERR("Unable to set group on " LTTNG_RUNDIR);
2395 perror("chown");
2396 }
2397
2398 /* lttng client socket path */
2399 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
2400 if (ret < 0) {
2401 ERR("Unable to set group on %s", client_unix_sock_path);
2402 perror("chown");
2403 }
2404
2405 /* kconsumerd error socket path */
2406 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
2407 if (ret < 0) {
2408 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2409 perror("chown");
2410 }
2411
2412 DBG("All permissions are set");
2413
2414 end:
2415 return ret;
2416 }
2417
2418 /*
2419 * Create the pipe used to wake up the kernel thread.
2420 */
2421 static int create_kernel_poll_pipe(void)
2422 {
2423 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2424 }
2425
2426 /*
2427 * Create the lttng run directory needed for all global sockets and pipe.
2428 */
2429 static int create_lttng_rundir(void)
2430 {
2431 int ret;
2432
2433 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2434 if (ret < 0) {
2435 if (errno != EEXIST) {
2436 ERR("Unable to create " LTTNG_RUNDIR);
2437 goto error;
2438 } else {
2439 ret = 0;
2440 }
2441 }
2442
2443 error:
2444 return ret;
2445 }
2446
2447 /*
2448 * Setup sockets and directory needed by the kconsumerd communication with the
2449 * session daemon.
2450 */
2451 static int set_kconsumerd_sockets(void)
2452 {
2453 int ret;
2454
2455 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2456 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2457 }
2458
2459 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2460 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2461 }
2462
2463 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2464 if (ret < 0) {
2465 if (errno != EEXIST) {
2466 ERR("Failed to create " KCONSUMERD_PATH);
2467 goto error;
2468 }
2469 ret = 0;
2470 }
2471
2472 /* Create the kconsumerd error unix socket */
2473 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2474 if (kconsumerd_err_sock < 0) {
2475 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2476 ret = -1;
2477 goto error;
2478 }
2479
2480 /* File permission MUST be 660 */
2481 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2482 if (ret < 0) {
2483 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2484 perror("chmod");
2485 goto error;
2486 }
2487
2488 error:
2489 return ret;
2490 }
2491
2492 /*
2493 * Signal handler for the daemon
2494 */
2495 static void sighandler(int sig)
2496 {
2497 switch (sig) {
2498 case SIGPIPE:
2499 DBG("SIGPIPE catched");
2500 return;
2501 case SIGINT:
2502 DBG("SIGINT catched");
2503 cleanup();
2504 break;
2505 case SIGTERM:
2506 DBG("SIGTERM catched");
2507 cleanup();
2508 break;
2509 default:
2510 break;
2511 }
2512
2513 exit(EXIT_SUCCESS);
2514 }
2515
2516 /*
2517 * Setup signal handler for :
2518 * SIGINT, SIGTERM, SIGPIPE
2519 */
2520 static int set_signal_handler(void)
2521 {
2522 int ret = 0;
2523 struct sigaction sa;
2524 sigset_t sigset;
2525
2526 if ((ret = sigemptyset(&sigset)) < 0) {
2527 perror("sigemptyset");
2528 return ret;
2529 }
2530
2531 sa.sa_handler = sighandler;
2532 sa.sa_mask = sigset;
2533 sa.sa_flags = 0;
2534 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2535 perror("sigaction");
2536 return ret;
2537 }
2538
2539 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2540 perror("sigaction");
2541 return ret;
2542 }
2543
2544 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2545 perror("sigaction");
2546 return ret;
2547 }
2548
2549 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2550
2551 return ret;
2552 }
2553
2554 /*
2555 * Set open files limit to unlimited. This daemon can open a large number of
2556 * file descriptors in order to consumer multiple kernel traces.
2557 */
2558 static void set_ulimit(void)
2559 {
2560 int ret;
2561 struct rlimit lim;
2562
2563 /* The kernel does not allowed an infinite limit for open files */
2564 lim.rlim_cur = 65535;
2565 lim.rlim_max = 65535;
2566
2567 ret = setrlimit(RLIMIT_NOFILE, &lim);
2568 if (ret < 0) {
2569 perror("failed to set open files limit");
2570 }
2571 }
2572
2573 /*
2574 * main
2575 */
2576 int main(int argc, char **argv)
2577 {
2578 int ret = 0;
2579 void *status;
2580 const char *home_path;
2581
2582 /* Create thread quit pipe */
2583 if (init_thread_quit_pipe() < 0) {
2584 goto exit;
2585 }
2586
2587 /* Parse arguments */
2588 progname = argv[0];
2589 if ((ret = parse_args(argc, argv) < 0)) {
2590 goto exit;
2591 }
2592
2593 /* Daemonize */
2594 if (opt_daemon) {
2595 ret = daemon(0, 0);
2596 if (ret < 0) {
2597 perror("daemon");
2598 goto exit;
2599 }
2600 }
2601
2602 /* Check if daemon is UID = 0 */
2603 is_root = !getuid();
2604
2605 if (is_root) {
2606 ret = create_lttng_rundir();
2607 if (ret < 0) {
2608 goto exit;
2609 }
2610
2611 if (strlen(apps_unix_sock_path) == 0) {
2612 snprintf(apps_unix_sock_path, PATH_MAX,
2613 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2614 }
2615
2616 if (strlen(client_unix_sock_path) == 0) {
2617 snprintf(client_unix_sock_path, PATH_MAX,
2618 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2619 }
2620 } else {
2621 home_path = get_home_dir();
2622 if (home_path == NULL) {
2623 /* TODO: Add --socket PATH option */
2624 ERR("Can't get HOME directory for sockets creation.");
2625 goto exit;
2626 }
2627
2628 if (strlen(apps_unix_sock_path) == 0) {
2629 snprintf(apps_unix_sock_path, PATH_MAX,
2630 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2631 }
2632
2633 /* Set the cli tool unix socket path */
2634 if (strlen(client_unix_sock_path) == 0) {
2635 snprintf(client_unix_sock_path, PATH_MAX,
2636 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2637 }
2638 }
2639
2640 DBG("Client socket path %s", client_unix_sock_path);
2641 DBG("Application socket path %s", apps_unix_sock_path);
2642
2643 /*
2644 * See if daemon already exist. If any of the two socket needed by the
2645 * daemon are present, this test fails. However, if the daemon is killed
2646 * with a SIGKILL, those unix socket must be unlinked by hand.
2647 */
2648 if ((ret = check_existing_daemon()) == 0) {
2649 ERR("Already running daemon.\n");
2650 /*
2651 * We do not goto error because we must not cleanup() because a daemon
2652 * is already running.
2653 */
2654 goto exit;
2655 }
2656
2657 /* After this point, we can safely call cleanup() so goto error is used */
2658
2659 /*
2660 * These actions must be executed as root. We do that *after* setting up
2661 * the sockets path because we MUST make the check for another daemon using
2662 * those paths *before* trying to set the kernel consumer sockets and init
2663 * kernel tracer.
2664 */
2665 if (is_root) {
2666 ret = set_kconsumerd_sockets();
2667 if (ret < 0) {
2668 goto error;
2669 }
2670
2671 /* Setup kernel tracer */
2672 init_kernel_tracer();
2673
2674 /* Set ulimit for open files */
2675 set_ulimit();
2676 }
2677
2678 if (set_signal_handler() < 0) {
2679 goto error;
2680 }
2681
2682 /* Setup the needed unix socket */
2683 if (init_daemon_socket() < 0) {
2684 goto error;
2685 }
2686
2687 /* Set credentials to socket */
2688 if (is_root && (set_permissions() < 0)) {
2689 goto error;
2690 }
2691
2692 /* Get parent pid if -S, --sig-parent is specified. */
2693 if (opt_sig_parent) {
2694 ppid = getppid();
2695 }
2696
2697 /* Setup the kernel pipe for waking up the kernel thread */
2698 if (create_kernel_poll_pipe() < 0) {
2699 goto error;
2700 }
2701
2702 /*
2703 * Get session list pointer. This pointer MUST NOT be free().
2704 * This list is statically declared in session.c
2705 */
2706 session_list_ptr = get_session_list();
2707
2708 while (1) {
2709 /* Create thread to manage the client socket */
2710 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2711 if (ret != 0) {
2712 perror("pthread_create");
2713 goto error;
2714 }
2715
2716 /* Create thread to manage application socket */
2717 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2718 if (ret != 0) {
2719 perror("pthread_create");
2720 goto error;
2721 }
2722
2723 /* Create kernel thread to manage kernel event */
2724 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2725 if (ret != 0) {
2726 perror("pthread_create");
2727 goto error;
2728 }
2729
2730 ret = pthread_join(client_thread, &status);
2731 if (ret != 0) {
2732 perror("pthread_join");
2733 goto error;
2734 }
2735 }
2736
2737 cleanup();
2738 exit(EXIT_SUCCESS);
2739
2740 error:
2741 cleanup();
2742
2743 exit:
2744 exit(EXIT_FAILURE);
2745 }
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