Fix channel creation when enabling an event
[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->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 defautl 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 * Process the command requested by the lttng client within the command
1195 * context structure. This function make sure that the return structure (llm)
1196 * is set and ready for transmission before returning.
1197 *
1198 * Return any error encountered or 0 for success.
1199 */
1200 static int process_client_msg(struct command_ctx *cmd_ctx)
1201 {
1202 int ret = LTTCOMM_OK;
1203
1204 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1205
1206 /* Listing commands don't need a session */
1207 switch (cmd_ctx->lsm->cmd_type) {
1208 case LTTNG_CREATE_SESSION:
1209 case LTTNG_LIST_SESSIONS:
1210 case LTTNG_LIST_EVENTS:
1211 case LTTNG_KERNEL_LIST_EVENTS:
1212 case LTTNG_LIST_TRACEABLE_APPS:
1213 break;
1214 default:
1215 DBG("Getting session %s by name", cmd_ctx->lsm->session_name);
1216 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name);
1217 if (cmd_ctx->session == NULL) {
1218 /* If session name not found */
1219 if (cmd_ctx->lsm->session_name != NULL) {
1220 ret = LTTCOMM_SESS_NOT_FOUND;
1221 } else { /* If no session name specified */
1222 ret = LTTCOMM_SELECT_SESS;
1223 }
1224 goto error;
1225 } else {
1226 /* Acquire lock for the session */
1227 lock_session(cmd_ctx->session);
1228 }
1229 break;
1230 }
1231
1232 /*
1233 * Check kernel command for kernel session.
1234 */
1235 switch (cmd_ctx->lsm->cmd_type) {
1236 case LTTNG_KERNEL_ADD_CONTEXT:
1237 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1238 case LTTNG_KERNEL_DISABLE_CHANNEL:
1239 case LTTNG_KERNEL_DISABLE_EVENT:
1240 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1241 case LTTNG_KERNEL_ENABLE_CHANNEL:
1242 case LTTNG_KERNEL_ENABLE_EVENT:
1243 case LTTNG_KERNEL_LIST_EVENTS:
1244 /* Kernel tracer check */
1245 if (kernel_tracer_fd == 0) {
1246 init_kernel_tracer();
1247 if (kernel_tracer_fd == 0) {
1248 ret = LTTCOMM_KERN_NA;
1249 goto error;
1250 }
1251 }
1252
1253 /* Need a session for kernel command */
1254 if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS &&
1255 cmd_ctx->session->kernel_session == NULL) {
1256
1257 ret = create_kernel_session(cmd_ctx->session);
1258 if (ret < 0) {
1259 ret = LTTCOMM_KERN_SESS_FAIL;
1260 goto error;
1261 }
1262
1263 /* Start the kernel consumer daemon */
1264 if (kconsumerd_pid == 0) {
1265 ret = start_kconsumerd();
1266 if (ret < 0) {
1267 goto error;
1268 }
1269 }
1270 }
1271 }
1272
1273 #ifdef DISABLED
1274 /* Connect to ust apps if available pid */
1275 if (cmd_ctx->lsm->pid > 0) {
1276 /* Connect to app using ustctl API */
1277 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
1278 if (cmd_ctx->ust_sock < 0) {
1279 ret = LTTCOMM_NO_TRACEABLE;
1280 goto error;
1281 }
1282 }
1283 #endif /* DISABLED */
1284
1285 /* Process by command type */
1286 switch (cmd_ctx->lsm->cmd_type) {
1287 case LTTNG_KERNEL_ADD_CONTEXT:
1288 {
1289 int found = 0, no_event = 0;
1290 struct ltt_kernel_channel *chan;
1291 struct ltt_kernel_event *event;
1292 struct lttng_kernel_context ctx;
1293
1294 /* Setup lttng message with no payload */
1295 ret = setup_lttng_msg(cmd_ctx, 0);
1296 if (ret < 0) {
1297 goto setup_error;
1298 }
1299
1300 /* Check if event name is given */
1301 if (strlen(cmd_ctx->lsm->u.context.event_name) == 0) {
1302 no_event = 1;
1303 }
1304
1305 /* Create Kernel context */
1306 ctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1307 ctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1308 ctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1309 strncpy(ctx.u.perf_counter.name,
1310 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1311 sizeof(ctx.u.perf_counter.name));
1312
1313 if (strlen(cmd_ctx->lsm->u.context.channel_name) == 0) {
1314 /* Go over all channels */
1315 DBG("Adding context to all channels");
1316 cds_list_for_each_entry(chan,
1317 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1318 if (no_event) {
1319 ret = kernel_add_channel_context(chan, &ctx);
1320 if (ret < 0) {
1321 continue;
1322 }
1323 } else {
1324 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1325 if (event != NULL) {
1326 ret = kernel_add_event_context(event, &ctx);
1327 if (ret < 0) {
1328 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1329 goto error;
1330 }
1331 found = 1;
1332 break;
1333 }
1334 }
1335 }
1336 } else {
1337 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.context.channel_name,
1338 cmd_ctx->session->kernel_session);
1339 if (chan == NULL) {
1340 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1341 goto error;
1342 }
1343
1344 if (no_event) {
1345 ret = kernel_add_channel_context(chan, &ctx);
1346 if (ret < 0) {
1347 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1348 goto error;
1349 }
1350 } else {
1351 event = get_kernel_event_by_name(cmd_ctx->lsm->u.context.event_name, chan);
1352 if (event != NULL) {
1353 ret = kernel_add_event_context(event, &ctx);
1354 if (ret < 0) {
1355 ret = LTTCOMM_KERN_CONTEXT_FAIL;
1356 goto error;
1357 }
1358 }
1359 }
1360 }
1361
1362 if (!found && !no_event) {
1363 ret = LTTCOMM_NO_EVENT;
1364 goto error;
1365 }
1366
1367 ret = LTTCOMM_OK;
1368 break;
1369 }
1370 case LTTNG_KERNEL_DISABLE_CHANNEL:
1371 {
1372 struct ltt_kernel_channel *chan;
1373
1374 /* Setup lttng message with no payload */
1375 ret = setup_lttng_msg(cmd_ctx, 0);
1376 if (ret < 0) {
1377 goto setup_error;
1378 }
1379
1380 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1381 cmd_ctx->session->kernel_session);
1382 if (chan == NULL) {
1383 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1384 goto error;
1385 } else if (chan->enabled == 1) {
1386 ret = kernel_disable_channel(chan);
1387 if (ret < 0) {
1388 if (ret != EEXIST) {
1389 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1390 }
1391 goto error;
1392 }
1393 }
1394
1395 kernel_wait_quiescent(kernel_tracer_fd);
1396 ret = LTTCOMM_OK;
1397 break;
1398 }
1399 case LTTNG_KERNEL_DISABLE_EVENT:
1400 {
1401 struct ltt_kernel_channel *chan;
1402 struct ltt_kernel_event *ev;
1403
1404 /* Setup lttng message with no payload */
1405 ret = setup_lttng_msg(cmd_ctx, 0);
1406 if (ret < 0) {
1407 goto setup_error;
1408 }
1409
1410 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1411 cmd_ctx->session->kernel_session);
1412 if (chan == NULL) {
1413 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1414 goto error;
1415 }
1416
1417 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, chan);
1418 if (ev != NULL) {
1419 DBG("Disabling kernel event %s for channel %s.",
1420 cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name);
1421 ret = kernel_disable_event(ev);
1422 if (ret < 0) {
1423 ret = LTTCOMM_KERN_ENABLE_FAIL;
1424 goto error;
1425 }
1426 }
1427
1428 kernel_wait_quiescent(kernel_tracer_fd);
1429 ret = LTTCOMM_OK;
1430 break;
1431 }
1432 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
1433 {
1434 struct ltt_kernel_channel *chan;
1435 struct ltt_kernel_event *ev;
1436
1437 /* Setup lttng message with no payload */
1438 ret = setup_lttng_msg(cmd_ctx, 0);
1439 if (ret < 0) {
1440 goto setup_error;
1441 }
1442
1443 DBG("Disabling all enabled kernel events");
1444
1445 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1446 cmd_ctx->session->kernel_session);
1447 if (chan == NULL) {
1448 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1449 goto error;
1450 }
1451
1452 /* For each event in the kernel session */
1453 cds_list_for_each_entry(ev, &chan->events_list.head, list) {
1454 DBG("Disabling kernel event %s for channel %s.",
1455 ev->event->name, cmd_ctx->lsm->u.disable.channel_name);
1456 ret = kernel_disable_event(ev);
1457 if (ret < 0) {
1458 continue;
1459 }
1460 }
1461
1462 /* Quiescent wait after event disable */
1463 kernel_wait_quiescent(kernel_tracer_fd);
1464 ret = LTTCOMM_OK;
1465 break;
1466 }
1467 case LTTNG_KERNEL_ENABLE_CHANNEL:
1468 {
1469 struct ltt_kernel_channel *chan;
1470
1471 /* Setup lttng message with no payload */
1472 ret = setup_lttng_msg(cmd_ctx, 0);
1473 if (ret < 0) {
1474 goto setup_error;
1475 }
1476
1477 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1478 cmd_ctx->session->kernel_session);
1479 if (chan == NULL) {
1480 /* Channel not found, creating it */
1481 DBG("Creating kernel channel");
1482
1483 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1484 &cmd_ctx->lsm->u.channel.chan, cmd_ctx->session->path);
1485 if (ret < 0) {
1486 ret = LTTCOMM_KERN_CHAN_FAIL;
1487 goto error;
1488 }
1489
1490 /* Notify kernel thread that there is a new channel */
1491 ret = notify_kernel_pollfd();
1492 if (ret < 0) {
1493 ret = LTTCOMM_FATAL;
1494 goto error;
1495 }
1496 } else if (chan->enabled == 0) {
1497 ret = kernel_enable_channel(chan);
1498 if (ret < 0) {
1499 if (ret != EEXIST) {
1500 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1501 }
1502 goto error;
1503 }
1504 }
1505
1506 kernel_wait_quiescent(kernel_tracer_fd);
1507 ret = LTTCOMM_OK;
1508 break;
1509 }
1510 case LTTNG_KERNEL_ENABLE_EVENT:
1511 {
1512 char *channel_name;
1513 struct ltt_kernel_channel *kchan;
1514 struct ltt_kernel_event *ev;
1515 struct lttng_channel *chan;
1516
1517 /* Setup lttng message with no payload */
1518 ret = setup_lttng_msg(cmd_ctx, 0);
1519 if (ret < 0) {
1520 goto setup_error;
1521 }
1522
1523 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1524
1525 do {
1526 kchan = get_kernel_channel_by_name(channel_name,
1527 cmd_ctx->session->kernel_session);
1528 if (kchan == NULL) {
1529 DBG("Channel not found. Creating channel %s", channel_name);
1530
1531 chan = init_default_channel(channel_name);
1532 if (chan == NULL) {
1533 ret = LTTCOMM_FATAL;
1534 goto error;
1535 }
1536
1537 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1538 chan, cmd_ctx->session->path);
1539 if (ret < 0) {
1540 ret = LTTCOMM_KERN_CHAN_FAIL;
1541 goto error;
1542 }
1543 }
1544 } while (kchan == NULL);
1545
1546 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
1547 if (ev == NULL) {
1548 DBG("Creating kernel event %s for channel %s.",
1549 cmd_ctx->lsm->u.enable.event.name, channel_name);
1550 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
1551 } else {
1552 DBG("Enabling kernel event %s for channel %s.",
1553 cmd_ctx->lsm->u.enable.event.name, channel_name);
1554 ret = kernel_enable_event(ev);
1555 if (ret == -EEXIST) {
1556 ret = LTTCOMM_KERN_EVENT_EXIST;
1557 goto error;
1558 }
1559 }
1560
1561 if (ret < 0) {
1562 ret = LTTCOMM_KERN_ENABLE_FAIL;
1563 goto error;
1564 }
1565
1566 kernel_wait_quiescent(kernel_tracer_fd);
1567 ret = LTTCOMM_OK;
1568 break;
1569 }
1570 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
1571 {
1572 int pos, size;
1573 char *event_list, *event, *ptr, *channel_name;
1574 struct ltt_kernel_channel *kchan;
1575 struct ltt_kernel_event *ev;
1576 struct lttng_event ev_attr;
1577 struct lttng_channel *chan;
1578
1579 /* Setup lttng message with no payload */
1580 ret = setup_lttng_msg(cmd_ctx, 0);
1581 if (ret < 0) {
1582 goto setup_error;
1583 }
1584
1585 DBG("Enabling all kernel event");
1586
1587 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1588
1589 do {
1590 kchan = get_kernel_channel_by_name(channel_name,
1591 cmd_ctx->session->kernel_session);
1592 if (kchan == NULL) {
1593 DBG("Channel not found. Creating channel %s", channel_name);
1594
1595 chan = init_default_channel(channel_name);
1596 if (chan == NULL) {
1597 ret = LTTCOMM_FATAL;
1598 goto error;
1599 }
1600
1601 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1602 chan, cmd_ctx->session->path);
1603 if (ret < 0) {
1604 ret = LTTCOMM_KERN_CHAN_FAIL;
1605 goto error;
1606 }
1607 }
1608 } while (kchan == NULL);
1609
1610 /* For each event in the kernel session */
1611 cds_list_for_each_entry(ev, &kchan->events_list.head, list) {
1612 DBG("Enabling kernel event %s for channel %s.",
1613 ev->event->name, channel_name);
1614 ret = kernel_enable_event(ev);
1615 if (ret < 0) {
1616 continue;
1617 }
1618 }
1619
1620 size = kernel_list_events(kernel_tracer_fd, &event_list);
1621 if (size < 0) {
1622 ret = LTTCOMM_KERN_LIST_FAIL;
1623 goto error;
1624 }
1625
1626 ptr = event_list;
1627 while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
1628 ev = get_kernel_event_by_name(event, kchan);
1629 if (ev == NULL) {
1630 strncpy(ev_attr.name, event, LTTNG_SYM_NAME_LEN);
1631 /* Default event type for enable all */
1632 ev_attr.type = LTTNG_EVENT_TRACEPOINT;
1633 /* Enable each single tracepoint event */
1634 ret = kernel_create_event(&ev_attr, kchan);
1635 if (ret < 0) {
1636 /* Ignore error here and continue */
1637 }
1638 }
1639
1640 /* Move pointer to the next line */
1641 ptr += pos + 1;
1642 free(event);
1643 }
1644
1645 free(event_list);
1646
1647 /* Quiescent wait after event enable */
1648 kernel_wait_quiescent(kernel_tracer_fd);
1649 ret = LTTCOMM_OK;
1650 break;
1651 }
1652 case LTTNG_KERNEL_LIST_EVENTS:
1653 {
1654 char *event_list;
1655 ssize_t size = 0;
1656
1657 DBG("Listing kernel events");
1658
1659 size = kernel_list_events(kernel_tracer_fd, &event_list);
1660 if (size < 0) {
1661 ret = LTTCOMM_KERN_LIST_FAIL;
1662 goto error;
1663 }
1664
1665 /*
1666 * Setup lttng message with payload size set to the event list size in
1667 * bytes and then copy list into the llm payload.
1668 */
1669 ret = setup_lttng_msg(cmd_ctx, size);
1670 if (ret < 0) {
1671 goto setup_error;
1672 }
1673
1674 /* Copy event list into message payload */
1675 memcpy(cmd_ctx->llm->payload, event_list, size);
1676
1677 free(event_list);
1678
1679 ret = LTTCOMM_OK;
1680 break;
1681 }
1682 case LTTNG_START_TRACE:
1683 {
1684 struct ltt_kernel_channel *chan;
1685
1686 /* Setup lttng message with no payload */
1687 ret = setup_lttng_msg(cmd_ctx, 0);
1688 if (ret < 0) {
1689 goto setup_error;
1690 }
1691
1692 /* Kernel tracing */
1693 if (cmd_ctx->session->kernel_session != NULL) {
1694 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1695 DBG("Open kernel metadata");
1696 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1697 cmd_ctx->session->path);
1698 if (ret < 0) {
1699 ret = LTTCOMM_KERN_META_FAIL;
1700 goto error;
1701 }
1702 }
1703
1704 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1705 DBG("Opening kernel metadata stream");
1706 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1707 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1708 if (ret < 0) {
1709 ERR("Kernel create metadata stream failed");
1710 ret = LTTCOMM_KERN_STREAM_FAIL;
1711 goto error;
1712 }
1713 }
1714 }
1715
1716 /* For each channel */
1717 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1718 if (chan->stream_count == 0) {
1719 ret = kernel_open_channel_stream(chan);
1720 if (ret < 0) {
1721 ERR("Kernel create channel stream failed");
1722 ret = LTTCOMM_KERN_STREAM_FAIL;
1723 goto error;
1724 }
1725 /* Update the stream global counter */
1726 cmd_ctx->session->kernel_session->stream_count_global += ret;
1727 }
1728 }
1729
1730 DBG("Start kernel tracing");
1731 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1732 if (ret < 0) {
1733 ERR("Kernel start session failed");
1734 ret = LTTCOMM_KERN_START_FAIL;
1735 goto error;
1736 }
1737
1738 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1739 if (ret < 0) {
1740 ret = LTTCOMM_KERN_START_FAIL;
1741 goto error;
1742 }
1743
1744 /* Quiescent wait after starting trace */
1745 kernel_wait_quiescent(kernel_tracer_fd);
1746 }
1747
1748 /* TODO: Start all UST traces */
1749
1750 ret = LTTCOMM_OK;
1751 break;
1752 }
1753 case LTTNG_STOP_TRACE:
1754 {
1755 struct ltt_kernel_channel *chan;
1756 /* Setup lttng message with no payload */
1757 ret = setup_lttng_msg(cmd_ctx, 0);
1758 if (ret < 0) {
1759 goto setup_error;
1760 }
1761
1762 /* Kernel tracer */
1763 if (cmd_ctx->session->kernel_session != NULL) {
1764 DBG("Stop kernel tracing");
1765
1766 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
1767 if (ret < 0) {
1768 ERR("Kernel metadata flush failed");
1769 }
1770
1771 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1772 ret = kernel_flush_buffer(chan);
1773 if (ret < 0) {
1774 ERR("Kernel flush buffer error");
1775 }
1776 }
1777
1778 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
1779 if (ret < 0) {
1780 ERR("Kernel stop session failed");
1781 ret = LTTCOMM_KERN_STOP_FAIL;
1782 goto error;
1783 }
1784
1785 /* Quiescent wait after stopping trace */
1786 kernel_wait_quiescent(kernel_tracer_fd);
1787 }
1788
1789 /* TODO : User-space tracer */
1790
1791 ret = LTTCOMM_OK;
1792 break;
1793 }
1794 case LTTNG_CREATE_SESSION:
1795 {
1796 /* Setup lttng message with no payload */
1797 ret = setup_lttng_msg(cmd_ctx, 0);
1798 if (ret < 0) {
1799 goto setup_error;
1800 }
1801
1802 ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path);
1803 if (ret < 0) {
1804 if (ret == -EEXIST) {
1805 ret = LTTCOMM_EXIST_SESS;
1806 } else {
1807 ret = LTTCOMM_FATAL;
1808 }
1809 goto error;
1810 }
1811
1812 ret = LTTCOMM_OK;
1813 break;
1814 }
1815 case LTTNG_DESTROY_SESSION:
1816 {
1817 /* Setup lttng message with no payload */
1818 ret = setup_lttng_msg(cmd_ctx, 0);
1819 if (ret < 0) {
1820 goto setup_error;
1821 }
1822
1823 /* Clean kernel session teardown */
1824 teardown_kernel_session(cmd_ctx->session);
1825
1826 ret = destroy_session(cmd_ctx->lsm->session_name);
1827 if (ret < 0) {
1828 ret = LTTCOMM_FATAL;
1829 goto error;
1830 }
1831
1832 /*
1833 * Must notify the kernel thread here to update it's pollfd in order to
1834 * remove the channel(s)' fd just destroyed.
1835 */
1836 ret = notify_kernel_pollfd();
1837 if (ret < 0) {
1838 ret = LTTCOMM_FATAL;
1839 goto error;
1840 }
1841
1842 ret = LTTCOMM_OK;
1843 break;
1844 }
1845 /*
1846 case LTTNG_LIST_TRACES:
1847 {
1848 unsigned int trace_count;
1849
1850 trace_count = get_trace_count_per_session(cmd_ctx->session);
1851 if (trace_count == 0) {
1852 ret = LTTCOMM_NO_TRACE;
1853 goto error;
1854 }
1855
1856 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
1857 if (ret < 0) {
1858 goto setup_error;
1859 }
1860
1861 get_traces_per_session(cmd_ctx->session,
1862 (struct lttng_trace *)(cmd_ctx->llm->payload));
1863
1864 ret = LTTCOMM_OK;
1865 break;
1866 }
1867 */
1868 /*
1869 case UST_CREATE_TRACE:
1870 {
1871 ret = setup_lttng_msg(cmd_ctx, 0);
1872 if (ret < 0) {
1873 goto setup_error;
1874 }
1875
1876 ret = ust_create_trace(cmd_ctx);
1877 if (ret < 0) {
1878 goto error;
1879 }
1880 break;
1881 }
1882 */
1883 case LTTNG_LIST_TRACEABLE_APPS:
1884 {
1885 unsigned int app_count;
1886
1887 app_count = get_app_count();
1888 DBG("Traceable application count : %d", app_count);
1889 if (app_count == 0) {
1890 ret = LTTCOMM_NO_APPS;
1891 goto error;
1892 }
1893
1894 ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
1895 if (ret < 0) {
1896 goto setup_error;
1897 }
1898
1899 get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
1900
1901 ret = LTTCOMM_OK;
1902 break;
1903 }
1904 /*
1905 case UST_START_TRACE:
1906 {
1907 ret = setup_lttng_msg(cmd_ctx, 0);
1908 if (ret < 0) {
1909 goto setup_error;
1910 }
1911
1912 ret = ust_start_trace(cmd_ctx);
1913 if (ret < 0) {
1914 goto setup_error;
1915 }
1916 break;
1917 }
1918 case UST_STOP_TRACE:
1919 {
1920 ret = setup_lttng_msg(cmd_ctx, 0);
1921 if (ret < 0) {
1922 goto setup_error;
1923 }
1924
1925 ret = ust_stop_trace(cmd_ctx);
1926 if (ret < 0) {
1927 goto setup_error;
1928 }
1929 break;
1930 }
1931 */
1932 case LTTNG_LIST_SESSIONS:
1933 {
1934 lock_session_list();
1935
1936 if (session_list_ptr->count == 0) {
1937 ret = LTTCOMM_NO_SESSION;
1938 goto error;
1939 }
1940
1941 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
1942 session_list_ptr->count);
1943 if (ret < 0) {
1944 goto setup_error;
1945 }
1946
1947 /* Filled the session array */
1948 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
1949
1950 unlock_session_list();
1951
1952 ret = LTTCOMM_OK;
1953 break;
1954 }
1955 default:
1956 /* Undefined command */
1957 ret = setup_lttng_msg(cmd_ctx, 0);
1958 if (ret < 0) {
1959 goto setup_error;
1960 }
1961
1962 ret = LTTCOMM_UND;
1963 break;
1964 }
1965
1966 /* Set return code */
1967 cmd_ctx->llm->ret_code = ret;
1968
1969 if (cmd_ctx->session) {
1970 unlock_session(cmd_ctx->session);
1971 }
1972
1973 return ret;
1974
1975 error:
1976 if (cmd_ctx->llm == NULL) {
1977 DBG("Missing llm structure. Allocating one.");
1978 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
1979 goto setup_error;
1980 }
1981 }
1982 /* Notify client of error */
1983 cmd_ctx->llm->ret_code = ret;
1984
1985 setup_error:
1986 if (cmd_ctx->session) {
1987 unlock_session(cmd_ctx->session);
1988 }
1989 return ret;
1990 }
1991
1992 /*
1993 * This thread manage all clients request using the unix client socket for
1994 * communication.
1995 */
1996 static void *thread_manage_clients(void *data)
1997 {
1998 int sock = 0, ret;
1999 struct command_ctx *cmd_ctx = NULL;
2000 struct pollfd pollfd[2];
2001
2002 DBG("[thread] Manage client started");
2003
2004 ret = lttcomm_listen_unix_sock(client_sock);
2005 if (ret < 0) {
2006 goto error;
2007 }
2008
2009 /* First fd is always the quit pipe */
2010 pollfd[0].fd = thread_quit_pipe[0];
2011
2012 /* Apps socket */
2013 pollfd[1].fd = client_sock;
2014 pollfd[1].events = POLLIN;
2015
2016 /* Notify parent pid that we are ready
2017 * to accept command for client side.
2018 */
2019 if (opt_sig_parent) {
2020 kill(ppid, SIGCHLD);
2021 }
2022
2023 while (1) {
2024 DBG("Accepting client command ...");
2025
2026 /* Inifinite blocking call, waiting for transmission */
2027 ret = poll(pollfd, 2, -1);
2028 if (ret < 0) {
2029 perror("poll client thread");
2030 goto error;
2031 }
2032
2033 /* Thread quit pipe has been closed. Killing thread. */
2034 if (pollfd[0].revents == POLLNVAL) {
2035 goto error;
2036 } else if (pollfd[1].revents == POLLERR) {
2037 ERR("Client socket poll error");
2038 goto error;
2039 }
2040
2041 sock = lttcomm_accept_unix_sock(client_sock);
2042 if (sock < 0) {
2043 goto error;
2044 }
2045
2046 /* Allocate context command to process the client request */
2047 cmd_ctx = malloc(sizeof(struct command_ctx));
2048
2049 /* Allocate data buffer for reception */
2050 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2051 cmd_ctx->llm = NULL;
2052 cmd_ctx->session = NULL;
2053
2054 /*
2055 * Data is received from the lttng client. The struct
2056 * lttcomm_session_msg (lsm) contains the command and data request of
2057 * the client.
2058 */
2059 DBG("Receiving data from client ...");
2060 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2061 if (ret <= 0) {
2062 continue;
2063 }
2064
2065 // TODO: Validate cmd_ctx including sanity check for security purpose.
2066
2067 /*
2068 * This function dispatch the work to the kernel or userspace tracer
2069 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2070 * informations for the client. The command context struct contains
2071 * everything this function may needs.
2072 */
2073 ret = process_client_msg(cmd_ctx);
2074 if (ret < 0) {
2075 /* TODO: Inform client somehow of the fatal error. At this point,
2076 * ret < 0 means that a malloc failed (ENOMEM). */
2077 /* Error detected but still accept command */
2078 clean_command_ctx(&cmd_ctx);
2079 continue;
2080 }
2081
2082 DBG("Sending response (size: %d, retcode: %d)",
2083 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2084 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2085 if (ret < 0) {
2086 ERR("Failed to send data back to client");
2087 }
2088
2089 clean_command_ctx(&cmd_ctx);
2090
2091 /* End of transmission */
2092 close(sock);
2093 }
2094
2095 error:
2096 DBG("Client thread dying");
2097 if (client_sock) {
2098 close(client_sock);
2099 }
2100 if (sock) {
2101 close(sock);
2102 }
2103
2104 unlink(client_unix_sock_path);
2105
2106 clean_command_ctx(&cmd_ctx);
2107 return NULL;
2108 }
2109
2110
2111 /*
2112 * usage function on stderr
2113 */
2114 static void usage(void)
2115 {
2116 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2117 fprintf(stderr, " -h, --help Display this usage.\n");
2118 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2119 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2120 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2121 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2122 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2123 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2124 fprintf(stderr, " -V, --version Show version number.\n");
2125 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2126 fprintf(stderr, " -q, --quiet No output at all.\n");
2127 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2128 }
2129
2130 /*
2131 * daemon argument parsing
2132 */
2133 static int parse_args(int argc, char **argv)
2134 {
2135 int c;
2136
2137 static struct option long_options[] = {
2138 { "client-sock", 1, 0, 'c' },
2139 { "apps-sock", 1, 0, 'a' },
2140 { "kconsumerd-cmd-sock", 1, 0, 0 },
2141 { "kconsumerd-err-sock", 1, 0, 0 },
2142 { "daemonize", 0, 0, 'd' },
2143 { "sig-parent", 0, 0, 'S' },
2144 { "help", 0, 0, 'h' },
2145 { "group", 1, 0, 'g' },
2146 { "version", 0, 0, 'V' },
2147 { "quiet", 0, 0, 'q' },
2148 { "verbose", 0, 0, 'v' },
2149 { NULL, 0, 0, 0 }
2150 };
2151
2152 while (1) {
2153 int option_index = 0;
2154 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
2155 if (c == -1) {
2156 break;
2157 }
2158
2159 switch (c) {
2160 case 0:
2161 fprintf(stderr, "option %s", long_options[option_index].name);
2162 if (optarg) {
2163 fprintf(stderr, " with arg %s\n", optarg);
2164 }
2165 break;
2166 case 'c':
2167 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2168 break;
2169 case 'a':
2170 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2171 break;
2172 case 'd':
2173 opt_daemon = 1;
2174 break;
2175 case 'g':
2176 opt_tracing_group = strdup(optarg);
2177 break;
2178 case 'h':
2179 usage();
2180 exit(EXIT_FAILURE);
2181 case 'V':
2182 fprintf(stdout, "%s\n", VERSION);
2183 exit(EXIT_SUCCESS);
2184 case 'S':
2185 opt_sig_parent = 1;
2186 break;
2187 case 'E':
2188 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2189 break;
2190 case 'C':
2191 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2192 break;
2193 case 'q':
2194 opt_quiet = 1;
2195 break;
2196 case 'v':
2197 /* Verbose level can increase using multiple -v */
2198 opt_verbose += 1;
2199 break;
2200 default:
2201 /* Unknown option or other error.
2202 * Error is printed by getopt, just return */
2203 return -1;
2204 }
2205 }
2206
2207 return 0;
2208 }
2209
2210 /*
2211 * Creates the two needed socket by the daemon.
2212 * apps_sock - The communication socket for all UST apps.
2213 * client_sock - The communication of the cli tool (lttng).
2214 */
2215 static int init_daemon_socket()
2216 {
2217 int ret = 0;
2218 mode_t old_umask;
2219
2220 old_umask = umask(0);
2221
2222 /* Create client tool unix socket */
2223 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2224 if (client_sock < 0) {
2225 ERR("Create unix sock failed: %s", client_unix_sock_path);
2226 ret = -1;
2227 goto end;
2228 }
2229
2230 /* File permission MUST be 660 */
2231 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2232 if (ret < 0) {
2233 ERR("Set file permissions failed: %s", client_unix_sock_path);
2234 perror("chmod");
2235 goto end;
2236 }
2237
2238 /* Create the application unix socket */
2239 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2240 if (apps_sock < 0) {
2241 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2242 ret = -1;
2243 goto end;
2244 }
2245
2246 /* File permission MUST be 666 */
2247 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2248 if (ret < 0) {
2249 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2250 perror("chmod");
2251 goto end;
2252 }
2253
2254 end:
2255 umask(old_umask);
2256 return ret;
2257 }
2258
2259 /*
2260 * Check if the global socket is available. If yes, error is returned.
2261 */
2262 static int check_existing_daemon()
2263 {
2264 int ret;
2265
2266 ret = access(client_unix_sock_path, F_OK);
2267 if (ret == 0) {
2268 ret = access(apps_unix_sock_path, F_OK);
2269 }
2270
2271 return ret;
2272 }
2273
2274 /*
2275 * Set the tracing group gid onto the client socket.
2276 *
2277 * Race window between mkdir and chown is OK because we are going from more
2278 * permissive (root.root) to les permissive (root.tracing).
2279 */
2280 static int set_permissions(void)
2281 {
2282 int ret;
2283 struct group *grp;
2284
2285 /* Decide which group name to use */
2286 (opt_tracing_group != NULL) ?
2287 (grp = getgrnam(opt_tracing_group)) :
2288 (grp = getgrnam(default_tracing_group));
2289
2290 if (grp == NULL) {
2291 if (is_root) {
2292 WARN("No tracing group detected");
2293 ret = 0;
2294 } else {
2295 ERR("Missing tracing group. Aborting execution.");
2296 ret = -1;
2297 }
2298 goto end;
2299 }
2300
2301 /* Set lttng run dir */
2302 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
2303 if (ret < 0) {
2304 ERR("Unable to set group on " LTTNG_RUNDIR);
2305 perror("chown");
2306 }
2307
2308 /* lttng client socket path */
2309 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
2310 if (ret < 0) {
2311 ERR("Unable to set group on %s", client_unix_sock_path);
2312 perror("chown");
2313 }
2314
2315 /* kconsumerd error socket path */
2316 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
2317 if (ret < 0) {
2318 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2319 perror("chown");
2320 }
2321
2322 DBG("All permissions are set");
2323
2324 end:
2325 return ret;
2326 }
2327
2328 /*
2329 * Create the pipe used to wake up the kernel thread.
2330 */
2331 static int create_kernel_poll_pipe(void)
2332 {
2333 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2334 }
2335
2336 /*
2337 * Create the lttng run directory needed for all global sockets and pipe.
2338 */
2339 static int create_lttng_rundir(void)
2340 {
2341 int ret;
2342
2343 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2344 if (ret < 0) {
2345 if (errno != EEXIST) {
2346 ERR("Unable to create " LTTNG_RUNDIR);
2347 goto error;
2348 } else {
2349 ret = 0;
2350 }
2351 }
2352
2353 error:
2354 return ret;
2355 }
2356
2357 /*
2358 * Setup sockets and directory needed by the kconsumerd communication with the
2359 * session daemon.
2360 */
2361 static int set_kconsumerd_sockets(void)
2362 {
2363 int ret;
2364
2365 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2366 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2367 }
2368
2369 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2370 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2371 }
2372
2373 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2374 if (ret < 0) {
2375 if (errno != EEXIST) {
2376 ERR("Failed to create " KCONSUMERD_PATH);
2377 goto error;
2378 }
2379 ret = 0;
2380 }
2381
2382 /* Create the kconsumerd error unix socket */
2383 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2384 if (kconsumerd_err_sock < 0) {
2385 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2386 ret = -1;
2387 goto error;
2388 }
2389
2390 /* File permission MUST be 660 */
2391 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2392 if (ret < 0) {
2393 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2394 perror("chmod");
2395 goto error;
2396 }
2397
2398 error:
2399 return ret;
2400 }
2401
2402 /*
2403 * Signal handler for the daemon
2404 */
2405 static void sighandler(int sig)
2406 {
2407 switch (sig) {
2408 case SIGPIPE:
2409 DBG("SIGPIPE catched");
2410 return;
2411 case SIGINT:
2412 DBG("SIGINT catched");
2413 cleanup();
2414 break;
2415 case SIGTERM:
2416 DBG("SIGTERM catched");
2417 cleanup();
2418 break;
2419 default:
2420 break;
2421 }
2422
2423 exit(EXIT_SUCCESS);
2424 }
2425
2426 /*
2427 * Setup signal handler for :
2428 * SIGINT, SIGTERM, SIGPIPE
2429 */
2430 static int set_signal_handler(void)
2431 {
2432 int ret = 0;
2433 struct sigaction sa;
2434 sigset_t sigset;
2435
2436 if ((ret = sigemptyset(&sigset)) < 0) {
2437 perror("sigemptyset");
2438 return ret;
2439 }
2440
2441 sa.sa_handler = sighandler;
2442 sa.sa_mask = sigset;
2443 sa.sa_flags = 0;
2444 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2445 perror("sigaction");
2446 return ret;
2447 }
2448
2449 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2450 perror("sigaction");
2451 return ret;
2452 }
2453
2454 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2455 perror("sigaction");
2456 return ret;
2457 }
2458
2459 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2460
2461 return ret;
2462 }
2463
2464 /*
2465 * Set open files limit to unlimited. This daemon can open a large number of
2466 * file descriptors in order to consumer multiple kernel traces.
2467 */
2468 static void set_ulimit(void)
2469 {
2470 int ret;
2471 struct rlimit lim;
2472
2473 /* The kernel does not allowed an infinite limit for open files */
2474 lim.rlim_cur = 65535;
2475 lim.rlim_max = 65535;
2476
2477 ret = setrlimit(RLIMIT_NOFILE, &lim);
2478 if (ret < 0) {
2479 perror("failed to set open files limit");
2480 }
2481 }
2482
2483 /*
2484 * main
2485 */
2486 int main(int argc, char **argv)
2487 {
2488 int ret = 0;
2489 void *status;
2490 const char *home_path;
2491
2492 /* Create thread quit pipe */
2493 if (init_thread_quit_pipe() < 0) {
2494 goto exit;
2495 }
2496
2497 /* Parse arguments */
2498 progname = argv[0];
2499 if ((ret = parse_args(argc, argv) < 0)) {
2500 goto exit;
2501 }
2502
2503 /* Daemonize */
2504 if (opt_daemon) {
2505 ret = daemon(0, 0);
2506 if (ret < 0) {
2507 perror("daemon");
2508 goto exit;
2509 }
2510 }
2511
2512 /* Check if daemon is UID = 0 */
2513 is_root = !getuid();
2514
2515 if (is_root) {
2516 ret = create_lttng_rundir();
2517 if (ret < 0) {
2518 goto exit;
2519 }
2520
2521 if (strlen(apps_unix_sock_path) == 0) {
2522 snprintf(apps_unix_sock_path, PATH_MAX,
2523 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2524 }
2525
2526 if (strlen(client_unix_sock_path) == 0) {
2527 snprintf(client_unix_sock_path, PATH_MAX,
2528 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2529 }
2530 } else {
2531 home_path = get_home_dir();
2532 if (home_path == NULL) {
2533 /* TODO: Add --socket PATH option */
2534 ERR("Can't get HOME directory for sockets creation.");
2535 goto exit;
2536 }
2537
2538 if (strlen(apps_unix_sock_path) == 0) {
2539 snprintf(apps_unix_sock_path, PATH_MAX,
2540 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2541 }
2542
2543 /* Set the cli tool unix socket path */
2544 if (strlen(client_unix_sock_path) == 0) {
2545 snprintf(client_unix_sock_path, PATH_MAX,
2546 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2547 }
2548 }
2549
2550 DBG("Client socket path %s", client_unix_sock_path);
2551 DBG("Application socket path %s", apps_unix_sock_path);
2552
2553 /*
2554 * See if daemon already exist. If any of the two socket needed by the
2555 * daemon are present, this test fails. However, if the daemon is killed
2556 * with a SIGKILL, those unix socket must be unlinked by hand.
2557 */
2558 if ((ret = check_existing_daemon()) == 0) {
2559 ERR("Already running daemon.\n");
2560 /*
2561 * We do not goto error because we must not cleanup() because a daemon
2562 * is already running.
2563 */
2564 goto exit;
2565 }
2566
2567 /* After this point, we can safely call cleanup() so goto error is used */
2568
2569 /*
2570 * These actions must be executed as root. We do that *after* setting up
2571 * the sockets path because we MUST make the check for another daemon using
2572 * those paths *before* trying to set the kernel consumer sockets and init
2573 * kernel tracer.
2574 */
2575 if (is_root) {
2576 ret = set_kconsumerd_sockets();
2577 if (ret < 0) {
2578 goto error;
2579 }
2580
2581 /* Setup kernel tracer */
2582 init_kernel_tracer();
2583
2584 /* Set ulimit for open files */
2585 set_ulimit();
2586 }
2587
2588 if (set_signal_handler() < 0) {
2589 goto error;
2590 }
2591
2592 /* Setup the needed unix socket */
2593 if (init_daemon_socket() < 0) {
2594 goto error;
2595 }
2596
2597 /* Set credentials to socket */
2598 if (is_root && (set_permissions() < 0)) {
2599 goto error;
2600 }
2601
2602 /* Get parent pid if -S, --sig-parent is specified. */
2603 if (opt_sig_parent) {
2604 ppid = getppid();
2605 }
2606
2607 /* Setup the kernel pipe for waking up the kernel thread */
2608 if (create_kernel_poll_pipe() < 0) {
2609 goto error;
2610 }
2611
2612 /*
2613 * Get session list pointer. This pointer MUST NOT be free().
2614 * This list is statically declared in session.c
2615 */
2616 session_list_ptr = get_session_list();
2617
2618 while (1) {
2619 /* Create thread to manage the client socket */
2620 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2621 if (ret != 0) {
2622 perror("pthread_create");
2623 goto error;
2624 }
2625
2626 /* Create thread to manage application socket */
2627 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2628 if (ret != 0) {
2629 perror("pthread_create");
2630 goto error;
2631 }
2632
2633 /* Create kernel thread to manage kernel event */
2634 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2635 if (ret != 0) {
2636 perror("pthread_create");
2637 goto error;
2638 }
2639
2640 ret = pthread_join(client_thread, &status);
2641 if (ret != 0) {
2642 perror("pthread_join");
2643 goto error;
2644 }
2645 }
2646
2647 cleanup();
2648 exit(EXIT_SUCCESS);
2649
2650 error:
2651 cleanup();
2652
2653 exit:
2654 exit(EXIT_FAILURE);
2655 }
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