Modify default kernel channel size/number
[lttng-tools.git] / ltt-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; only version 2
8 * of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20 #define _GNU_SOURCE
21 #include <fcntl.h>
22 #include <getopt.h>
23 #include <grp.h>
24 #include <limits.h>
25 #include <poll.h>
26 #include <pthread.h>
27 #include <semaphore.h>
28 #include <signal.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <sys/ipc.h>
33 #include <sys/mount.h>
34 #include <sys/shm.h>
35 #include <sys/socket.h>
36 #include <sys/stat.h>
37 #include <sys/types.h>
38 #include <sys/time.h>
39 #include <sys/resource.h>
40 #include <unistd.h>
41
42 #include <urcu/list.h> /* URCU list library (-lurcu) */
43 #include <lttng/lttng.h>
44 #include <lttng/lttng-kconsumerd.h>
45 #include <lttng-sessiond-comm.h>
46
47 #include "context.h"
48 #include "ltt-sessiond.h"
49 #include "lttngerr.h"
50 #include "kernel-ctl.h"
51 #include "ust-ctl.h"
52 #include "session.h"
53 #include "traceable-app.h"
54 #include "ltt-kconsumerd.h"
55 #include "utils.h"
56
57 /* Const values */
58 const char default_home_dir[] = DEFAULT_HOME_DIR;
59 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
60 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
61 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
62
63 /* Variables */
64 int opt_verbose; /* Not static for lttngerr.h */
65 int opt_verbose_kconsumerd; /* Not static for lttngerr.h */
66 int opt_quiet; /* Not static for lttngerr.h */
67
68 const char *progname;
69 const char *opt_tracing_group;
70 static int opt_sig_parent;
71 static int opt_daemon;
72 static int is_root; /* Set to 1 if the daemon is running as root */
73 static pid_t ppid; /* Parent PID for --sig-parent option */
74 static pid_t kconsumerd_pid;
75 static struct pollfd *kernel_pollfd;
76
77 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
78 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
79 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
80 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
81
82 /* Sockets and FDs */
83 static int client_sock;
84 static int apps_sock;
85 static int kconsumerd_err_sock;
86 static int kconsumerd_cmd_sock;
87 static int kernel_tracer_fd;
88 static int kernel_poll_pipe[2];
89
90 /*
91 * Quit pipe for all threads. This permits a single cancellation point
92 * for all threads when receiving an event on the pipe.
93 */
94 static int thread_quit_pipe[2];
95
96 /* Pthread, Mutexes and Semaphores */
97 static pthread_t kconsumerd_thread;
98 static pthread_t apps_thread;
99 static pthread_t client_thread;
100 static pthread_t kernel_thread;
101 static sem_t kconsumerd_sem;
102
103 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
104
105 static int modprobe_remove_kernel_modules(void);
106
107 /*
108 * Pointer initialized before thread creation.
109 *
110 * This points to the tracing session list containing the session count and a
111 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
112 * MUST NOT be taken if you call a public function in session.c.
113 *
114 * The lock is nested inside the structure: session_list_ptr->lock. Please use
115 * lock_session_list and unlock_session_list for lock acquisition.
116 */
117 static struct ltt_session_list *session_list_ptr;
118
119 static gid_t allowed_group(void)
120 {
121 struct group *grp;
122
123 if (opt_tracing_group) {
124 grp = getgrnam(opt_tracing_group);
125 } else {
126 grp = getgrnam(default_tracing_group);
127 }
128 if (!grp) {
129 return -1;
130 } else {
131 return grp->gr_gid;
132 }
133 }
134
135 /*
136 * Init quit pipe.
137 *
138 * Return -1 on error or 0 if all pipes are created.
139 */
140 static int init_thread_quit_pipe(void)
141 {
142 int ret;
143
144 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
145 if (ret < 0) {
146 perror("thread quit pipe");
147 goto error;
148 }
149
150 error:
151 return ret;
152 }
153
154 /*
155 * Complete teardown of a kernel session. This free all data structure related
156 * to a kernel session and update counter.
157 */
158 static void teardown_kernel_session(struct ltt_session *session)
159 {
160 if (session->kernel_session != NULL) {
161 DBG("Tearing down kernel session");
162
163 /*
164 * If a custom kernel consumer was registered, close the socket before
165 * tearing down the complete kernel session structure
166 */
167 if (session->kernel_session->consumer_fd != kconsumerd_cmd_sock) {
168 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
169 }
170
171 trace_destroy_kernel_session(session->kernel_session);
172 /* Extra precaution */
173 session->kernel_session = NULL;
174 }
175 }
176
177 static void stop_threads(void)
178 {
179 /* Stopping all threads */
180 DBG("Terminating all threads");
181 close(thread_quit_pipe[0]);
182 close(thread_quit_pipe[1]);
183 }
184
185 /*
186 * Cleanup the daemon
187 */
188 static void cleanup(void)
189 {
190 int ret;
191 char *cmd;
192 struct ltt_session *sess, *stmp;
193
194 DBG("Cleaning up");
195
196 /* <fun> */
197 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
198 "Matthew, BEET driven development works!%c[%dm",
199 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
200 /* </fun> */
201
202 DBG("Removing %s directory", LTTNG_RUNDIR);
203 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
204 if (ret < 0) {
205 ERR("asprintf failed. Something is really wrong!");
206 }
207
208 /* Remove lttng run directory */
209 ret = system(cmd);
210 if (ret < 0) {
211 ERR("Unable to clean " LTTNG_RUNDIR);
212 }
213
214 DBG("Cleaning up all session");
215
216 /* Destroy session list mutex */
217 if (session_list_ptr != NULL) {
218 pthread_mutex_destroy(&session_list_ptr->lock);
219
220 /* Cleanup ALL session */
221 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
222 teardown_kernel_session(sess);
223 // TODO complete session cleanup (including UST)
224 }
225 }
226
227 pthread_mutex_destroy(&kconsumerd_pid_mutex);
228
229 DBG("Closing kernel fd");
230 close(kernel_tracer_fd);
231
232 DBG("Unloading kernel modules");
233 modprobe_remove_kernel_modules();
234 }
235
236 /*
237 * Send data on a unix socket using the liblttsessiondcomm API.
238 *
239 * Return lttcomm error code.
240 */
241 static int send_unix_sock(int sock, void *buf, size_t len)
242 {
243 /* Check valid length */
244 if (len <= 0) {
245 return -1;
246 }
247
248 return lttcomm_send_unix_sock(sock, buf, len);
249 }
250
251 /*
252 * Free memory of a command context structure.
253 */
254 static void clean_command_ctx(struct command_ctx **cmd_ctx)
255 {
256 DBG("Clean command context structure");
257 if (*cmd_ctx) {
258 if ((*cmd_ctx)->llm) {
259 free((*cmd_ctx)->llm);
260 }
261 if ((*cmd_ctx)->lsm) {
262 free((*cmd_ctx)->lsm);
263 }
264 free(*cmd_ctx);
265 *cmd_ctx = NULL;
266 }
267 }
268
269 /*
270 * Send all stream fds of kernel channel to the consumer.
271 */
272 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
273 {
274 int ret;
275 size_t nb_fd;
276 struct ltt_kernel_stream *stream;
277 struct lttcomm_kconsumerd_header lkh;
278 struct lttcomm_kconsumerd_msg lkm;
279
280 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
281
282 nb_fd = channel->stream_count;
283
284 /* Setup header */
285 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
286 lkh.cmd_type = ADD_STREAM;
287
288 DBG("Sending kconsumerd header");
289
290 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
291 if (ret < 0) {
292 perror("send kconsumerd header");
293 goto error;
294 }
295
296 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
297 if (stream->fd != 0) {
298 lkm.fd = stream->fd;
299 lkm.state = stream->state;
300 lkm.max_sb_size = channel->channel->attr.subbuf_size;
301 lkm.output = channel->channel->attr.output;
302 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
303 lkm.path_name[PATH_MAX - 1] = '\0';
304
305 DBG("Sending fd %d to kconsumerd", lkm.fd);
306
307 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
308 if (ret < 0) {
309 perror("send kconsumerd fd");
310 goto error;
311 }
312 }
313 }
314
315 DBG("Kconsumerd channel fds sent");
316
317 return 0;
318
319 error:
320 return ret;
321 }
322
323 /*
324 * Send all stream fds of the kernel session to the consumer.
325 */
326 static int send_kconsumerd_fds(struct ltt_kernel_session *session)
327 {
328 int ret;
329 struct ltt_kernel_channel *chan;
330 struct lttcomm_kconsumerd_header lkh;
331 struct lttcomm_kconsumerd_msg lkm;
332
333 /* Setup header */
334 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
335 lkh.cmd_type = ADD_STREAM;
336
337 DBG("Sending kconsumerd header for metadata");
338
339 ret = lttcomm_send_unix_sock(session->consumer_fd, &lkh, sizeof(struct lttcomm_kconsumerd_header));
340 if (ret < 0) {
341 perror("send kconsumerd header");
342 goto error;
343 }
344
345 DBG("Sending metadata stream fd");
346
347 /* Extra protection. It's NOT suppose to be set to 0 at this point */
348 if (session->consumer_fd == 0) {
349 session->consumer_fd = kconsumerd_cmd_sock;
350 }
351
352 if (session->metadata_stream_fd != 0) {
353 /* Send metadata stream fd first */
354 lkm.fd = session->metadata_stream_fd;
355 lkm.state = ACTIVE_FD;
356 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
357 lkm.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
358 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
359 lkm.path_name[PATH_MAX - 1] = '\0';
360
361 ret = lttcomm_send_fds_unix_sock(session->consumer_fd, &lkm, &lkm.fd, 1, sizeof(lkm));
362 if (ret < 0) {
363 perror("send kconsumerd fd");
364 goto error;
365 }
366 }
367
368 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
369 ret = send_kconsumerd_channel_fds(session->consumer_fd, chan);
370 if (ret < 0) {
371 goto error;
372 }
373 }
374
375 DBG("Kconsumerd fds (metadata and channel streams) sent");
376
377 return 0;
378
379 error:
380 return ret;
381 }
382
383 #ifdef DISABLED
384 /*
385 * Return a socket connected to the libust communication socket of the
386 * application identified by the pid.
387 *
388 * If the pid is not found in the traceable list, return -1 to indicate error.
389 */
390 static int ust_connect_app(pid_t pid)
391 {
392 int sock;
393 struct ltt_traceable_app *lta;
394
395 DBG("Connect to application pid %d", pid);
396
397 lta = find_app_by_pid(pid);
398 if (lta == NULL) {
399 /* App not found */
400 DBG("Application pid %d not found", pid);
401 return -1;
402 }
403
404 sock = ustctl_connect_pid(lta->pid);
405 if (sock < 0) {
406 ERR("Fail connecting to the PID %d", pid);
407 }
408
409 return sock;
410 }
411 #endif /* DISABLED */
412
413 /*
414 * Notify apps by writing 42 to a named pipe using name. Every applications
415 * waiting for a ltt-sessiond will be notified and re-register automatically to
416 * the session daemon.
417 *
418 * Return open or write error value.
419 */
420 static int notify_apps(const char *name)
421 {
422 int fd;
423 int ret = -1;
424
425 DBG("Notify the global application pipe");
426
427 /* Try opening the global pipe */
428 fd = open(name, O_WRONLY);
429 if (fd < 0) {
430 goto error;
431 }
432
433 /* Notify by writing on the pipe */
434 ret = write(fd, "42", 2);
435 if (ret < 0) {
436 perror("write");
437 }
438
439 error:
440 return ret;
441 }
442
443 /*
444 * Setup the outgoing data buffer for the response (llm) by allocating the
445 * right amount of memory and copying the original information from the lsm
446 * structure.
447 *
448 * Return total size of the buffer pointed by buf.
449 */
450 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
451 {
452 int ret, buf_size;
453
454 buf_size = size;
455
456 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
457 if (cmd_ctx->llm == NULL) {
458 perror("malloc");
459 ret = -ENOMEM;
460 goto error;
461 }
462
463 /* Copy common data */
464 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
465 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
466
467 cmd_ctx->llm->data_size = size;
468 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
469
470 return buf_size;
471
472 error:
473 return ret;
474 }
475
476 /*
477 * Update the kernel pollfd set of all channel fd available over all tracing
478 * session. Add the wakeup pipe at the end of the set.
479 */
480 static int update_kernel_pollfd(void)
481 {
482 int i = 0;
483 /*
484 * The wakup pipe and the quit pipe are needed so the number of fds starts
485 * at 2 for those pipes.
486 */
487 unsigned int nb_fd = 2;
488 struct ltt_session *session;
489 struct ltt_kernel_channel *channel;
490
491 DBG("Updating kernel_pollfd");
492
493 /* Get the number of channel of all kernel session */
494 lock_session_list();
495 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
496 lock_session(session);
497 if (session->kernel_session == NULL) {
498 unlock_session(session);
499 continue;
500 }
501 nb_fd += session->kernel_session->channel_count;
502 unlock_session(session);
503 }
504
505 DBG("Resizing kernel_pollfd to size %d", nb_fd);
506
507 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
508 if (kernel_pollfd == NULL) {
509 perror("malloc kernel_pollfd");
510 goto error;
511 }
512
513 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
514 lock_session(session);
515 if (session->kernel_session == NULL) {
516 unlock_session(session);
517 continue;
518 }
519 if (i >= nb_fd) {
520 ERR("To much channel for kernel_pollfd size");
521 unlock_session(session);
522 break;
523 }
524 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
525 kernel_pollfd[i].fd = channel->fd;
526 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
527 i++;
528 }
529 unlock_session(session);
530 }
531 unlock_session_list();
532
533 /* Adding wake up pipe */
534 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
535 kernel_pollfd[nb_fd - 2].events = POLLIN;
536
537 /* Adding the quit pipe */
538 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
539
540 return nb_fd;
541
542 error:
543 unlock_session_list();
544 return -1;
545 }
546
547 /*
548 * Find the channel fd from 'fd' over all tracing session. When found, check
549 * for new channel stream and send those stream fds to the kernel consumer.
550 *
551 * Useful for CPU hotplug feature.
552 */
553 static int update_kernel_stream(int fd)
554 {
555 int ret = 0;
556 struct ltt_session *session;
557 struct ltt_kernel_channel *channel;
558
559 DBG("Updating kernel streams for channel fd %d", fd);
560
561 lock_session_list();
562 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
563 lock_session(session);
564 if (session->kernel_session == NULL) {
565 unlock_session(session);
566 continue;
567 }
568
569 /* This is not suppose to be 0 but this is an extra security check */
570 if (session->kernel_session->consumer_fd == 0) {
571 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
572 }
573
574 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
575 if (channel->fd == fd) {
576 DBG("Channel found, updating kernel streams");
577 ret = kernel_open_channel_stream(channel);
578 if (ret < 0) {
579 goto end;
580 }
581
582 /*
583 * Have we already sent fds to the consumer? If yes, it means that
584 * tracing is started so it is safe to send our updated stream fds.
585 */
586 if (session->kernel_session->kconsumer_fds_sent == 1) {
587 ret = send_kconsumerd_channel_fds(session->kernel_session->consumer_fd,
588 channel);
589 if (ret < 0) {
590 goto end;
591 }
592 }
593 goto end;
594 }
595 }
596 unlock_session(session);
597 }
598
599 end:
600 unlock_session_list();
601 if (session) {
602 unlock_session(session);
603 }
604 return ret;
605 }
606
607 /*
608 * This thread manage event coming from the kernel.
609 *
610 * Features supported in this thread:
611 * -) CPU Hotplug
612 */
613 static void *thread_manage_kernel(void *data)
614 {
615 int ret, i, nb_fd = 0;
616 char tmp;
617 int update_poll_flag = 1;
618
619 DBG("Thread manage kernel started");
620
621 while (1) {
622 if (update_poll_flag == 1) {
623 nb_fd = update_kernel_pollfd();
624 if (nb_fd < 0) {
625 goto error;
626 }
627 update_poll_flag = 0;
628 }
629
630 DBG("Polling on %d fds", nb_fd);
631
632 /* Poll infinite value of time */
633 ret = poll(kernel_pollfd, nb_fd, -1);
634 if (ret < 0) {
635 perror("poll kernel thread");
636 goto error;
637 } else if (ret == 0) {
638 /* Should not happen since timeout is infinite */
639 continue;
640 }
641
642 /* Thread quit pipe has been closed. Killing thread. */
643 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
644 goto error;
645 }
646
647 DBG("Kernel poll event triggered");
648
649 /*
650 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
651 * must be updated.
652 */
653 switch (kernel_pollfd[nb_fd - 2].revents) {
654 case POLLIN:
655 ret = read(kernel_poll_pipe[0], &tmp, 1);
656 update_poll_flag = 1;
657 continue;
658 case POLLERR:
659 goto error;
660 default:
661 break;
662 }
663
664 for (i = 0; i < nb_fd; i++) {
665 switch (kernel_pollfd[i].revents) {
666 /*
667 * New CPU detected by the kernel. Adding kernel stream to kernel
668 * session and updating the kernel consumer
669 */
670 case POLLIN | POLLRDNORM:
671 ret = update_kernel_stream(kernel_pollfd[i].fd);
672 if (ret < 0) {
673 continue;
674 }
675 break;
676 }
677 }
678 }
679
680 error:
681 DBG("Kernel thread dying");
682 if (kernel_pollfd) {
683 free(kernel_pollfd);
684 }
685
686 close(kernel_poll_pipe[0]);
687 close(kernel_poll_pipe[1]);
688 return NULL;
689 }
690
691 /*
692 * This thread manage the kconsumerd error sent back to the session daemon.
693 */
694 static void *thread_manage_kconsumerd(void *data)
695 {
696 int sock = 0, ret;
697 enum lttcomm_return_code code;
698 struct pollfd pollfd[2];
699
700 DBG("[thread] Manage kconsumerd started");
701
702 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
703 if (ret < 0) {
704 goto error;
705 }
706
707 /* First fd is always the quit pipe */
708 pollfd[0].fd = thread_quit_pipe[0];
709
710 /* Apps socket */
711 pollfd[1].fd = kconsumerd_err_sock;
712 pollfd[1].events = POLLIN;
713
714 /* Inifinite blocking call, waiting for transmission */
715 ret = poll(pollfd, 2, -1);
716 if (ret < 0) {
717 perror("poll kconsumerd thread");
718 goto error;
719 }
720
721 /* Thread quit pipe has been closed. Killing thread. */
722 if (pollfd[0].revents == POLLNVAL) {
723 goto error;
724 } else if (pollfd[1].revents == POLLERR) {
725 ERR("Kconsumerd err socket poll error");
726 goto error;
727 }
728
729 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
730 if (sock < 0) {
731 goto error;
732 }
733
734 /* Getting status code from kconsumerd */
735 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
736 if (ret <= 0) {
737 goto error;
738 }
739
740 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
741 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
742 if (kconsumerd_cmd_sock < 0) {
743 sem_post(&kconsumerd_sem);
744 perror("kconsumerd connect");
745 goto error;
746 }
747 /* Signal condition to tell that the kconsumerd is ready */
748 sem_post(&kconsumerd_sem);
749 DBG("Kconsumerd command socket ready");
750 } else {
751 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
752 lttcomm_get_readable_code(-code));
753 goto error;
754 }
755
756 /* Wait for any kconsumerd error */
757 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
758 if (ret <= 0) {
759 ERR("Kconsumerd closed the command socket");
760 goto error;
761 }
762
763 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
764
765 error:
766 DBG("Kconsumerd thread dying");
767 if (kconsumerd_err_sock) {
768 close(kconsumerd_err_sock);
769 }
770 if (kconsumerd_cmd_sock) {
771 close(kconsumerd_cmd_sock);
772 }
773 if (sock) {
774 close(sock);
775 }
776
777 unlink(kconsumerd_err_unix_sock_path);
778 unlink(kconsumerd_cmd_unix_sock_path);
779
780 kconsumerd_pid = 0;
781 return NULL;
782 }
783
784 /*
785 * This thread manage the application socket communication
786 */
787 static void *thread_manage_apps(void *data)
788 {
789 int sock = 0, ret;
790 struct pollfd pollfd[2];
791
792 /* TODO: Something more elegant is needed but fine for now */
793 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
794 * for 32-bit vs 64-bit compat processes. */
795 /* replicate in ust with version number */
796 struct {
797 int reg; /* 1:register, 0:unregister */
798 pid_t pid;
799 uid_t uid;
800 } reg_msg;
801
802 DBG("[thread] Manage apps started");
803
804 ret = lttcomm_listen_unix_sock(apps_sock);
805 if (ret < 0) {
806 goto error;
807 }
808
809 /* First fd is always the quit pipe */
810 pollfd[0].fd = thread_quit_pipe[0];
811
812 /* Apps socket */
813 pollfd[1].fd = apps_sock;
814 pollfd[1].events = POLLIN;
815
816 /* Notify all applications to register */
817 notify_apps(default_global_apps_pipe);
818
819 while (1) {
820 DBG("Accepting application registration");
821
822 /* Inifinite blocking call, waiting for transmission */
823 ret = poll(pollfd, 2, -1);
824 if (ret < 0) {
825 perror("poll apps thread");
826 goto error;
827 }
828
829 /* Thread quit pipe has been closed. Killing thread. */
830 if (pollfd[0].revents == POLLNVAL) {
831 goto error;
832 } else if (pollfd[1].revents == POLLERR) {
833 ERR("Apps socket poll error");
834 goto error;
835 }
836
837 sock = lttcomm_accept_unix_sock(apps_sock);
838 if (sock < 0) {
839 goto error;
840 }
841
842 /*
843 * Basic recv here to handle the very simple data
844 * that the libust send to register (reg_msg).
845 */
846 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
847 if (ret < 0) {
848 perror("recv");
849 continue;
850 }
851
852 /* Add application to the global traceable list */
853 if (reg_msg.reg == 1) {
854 /* Registering */
855 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
856 if (ret < 0) {
857 /* register_traceable_app only return an error with
858 * ENOMEM. At this point, we better stop everything.
859 */
860 goto error;
861 }
862 } else {
863 /* Unregistering */
864 unregister_traceable_app(reg_msg.pid);
865 }
866 }
867
868 error:
869 DBG("Apps thread dying");
870 if (apps_sock) {
871 close(apps_sock);
872 }
873 if (sock) {
874 close(sock);
875 }
876
877 unlink(apps_unix_sock_path);
878 return NULL;
879 }
880
881 /*
882 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
883 * exec or it will fails.
884 */
885 static int spawn_kconsumerd_thread(void)
886 {
887 int ret;
888
889 /* Setup semaphore */
890 sem_init(&kconsumerd_sem, 0, 0);
891
892 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
893 if (ret != 0) {
894 perror("pthread_create kconsumerd");
895 goto error;
896 }
897
898 /* Wait for the kconsumerd thread to be ready */
899 sem_wait(&kconsumerd_sem);
900
901 if (kconsumerd_pid == 0) {
902 ERR("Kconsumerd did not start");
903 goto error;
904 }
905
906 return 0;
907
908 error:
909 ret = LTTCOMM_KERN_CONSUMER_FAIL;
910 return ret;
911 }
912
913 /*
914 * Join kernel consumer thread
915 */
916 static int join_kconsumerd_thread(void)
917 {
918 void *status;
919 int ret;
920
921 if (kconsumerd_pid != 0) {
922 ret = kill(kconsumerd_pid, SIGTERM);
923 if (ret) {
924 ERR("Error killing kconsumerd");
925 return ret;
926 }
927 return pthread_join(kconsumerd_thread, &status);
928 } else {
929 return 0;
930 }
931 }
932
933 /*
934 * Fork and exec a kernel consumer daemon (kconsumerd).
935 *
936 * Return pid if successful else -1.
937 */
938 static pid_t spawn_kconsumerd(void)
939 {
940 int ret;
941 pid_t pid;
942 const char *verbosity;
943
944 DBG("Spawning kconsumerd");
945
946 pid = fork();
947 if (pid == 0) {
948 /*
949 * Exec kconsumerd.
950 */
951 if (opt_verbose > 1 || opt_verbose_kconsumerd) {
952 verbosity = "--verbose";
953 } else {
954 verbosity = "--quiet";
955 }
956 execl(INSTALL_BIN_PATH "/ltt-kconsumerd", "ltt-kconsumerd", verbosity, NULL);
957 if (errno != 0) {
958 perror("kernel start consumer exec");
959 }
960 exit(EXIT_FAILURE);
961 } else if (pid > 0) {
962 ret = pid;
963 goto error;
964 } else {
965 perror("kernel start consumer fork");
966 ret = -errno;
967 goto error;
968 }
969
970 error:
971 return ret;
972 }
973
974 /*
975 * Spawn the kconsumerd daemon and session daemon thread.
976 */
977 static int start_kconsumerd(void)
978 {
979 int ret;
980
981 pthread_mutex_lock(&kconsumerd_pid_mutex);
982 if (kconsumerd_pid != 0) {
983 pthread_mutex_unlock(&kconsumerd_pid_mutex);
984 goto end;
985 }
986
987 ret = spawn_kconsumerd();
988 if (ret < 0) {
989 ERR("Spawning kconsumerd failed");
990 ret = LTTCOMM_KERN_CONSUMER_FAIL;
991 pthread_mutex_unlock(&kconsumerd_pid_mutex);
992 goto error;
993 }
994
995 /* Setting up the global kconsumerd_pid */
996 kconsumerd_pid = ret;
997 pthread_mutex_unlock(&kconsumerd_pid_mutex);
998
999 DBG("Kconsumerd pid %d", ret);
1000
1001 DBG("Spawning kconsumerd thread");
1002 ret = spawn_kconsumerd_thread();
1003 if (ret < 0) {
1004 ERR("Fatal error spawning kconsumerd thread");
1005 goto error;
1006 }
1007
1008 end:
1009 return 0;
1010
1011 error:
1012 return ret;
1013 }
1014
1015 /*
1016 * modprobe_kernel_modules
1017 */
1018 static int modprobe_kernel_modules(void)
1019 {
1020 int ret = 0, i;
1021 char modprobe[256];
1022
1023 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1024 ret = snprintf(modprobe, sizeof(modprobe),
1025 "/sbin/modprobe %s%s",
1026 kernel_modules_list[i].required ? "" : "--quiet ",
1027 kernel_modules_list[i].name);
1028 if (ret < 0) {
1029 perror("snprintf modprobe");
1030 goto error;
1031 }
1032 modprobe[sizeof(modprobe) - 1] = '\0';
1033 ret = system(modprobe);
1034 if (ret == -1) {
1035 ERR("Unable to launch modprobe for module %s",
1036 kernel_modules_list[i].name);
1037 } else if (kernel_modules_list[i].required
1038 && WEXITSTATUS(ret) != 0) {
1039 ERR("Unable to load module %s",
1040 kernel_modules_list[i].name);
1041 } else {
1042 DBG("Modprobe successfully %s",
1043 kernel_modules_list[i].name);
1044 }
1045 }
1046
1047 error:
1048 return ret;
1049 }
1050
1051 /*
1052 * modprobe_remove_kernel_modules
1053 * Remove modules in reverse load order.
1054 */
1055 static int modprobe_remove_kernel_modules(void)
1056 {
1057 int ret = 0, i;
1058 char modprobe[256];
1059
1060 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
1061 ret = snprintf(modprobe, sizeof(modprobe),
1062 "/sbin/modprobe --remove --quiet %s",
1063 kernel_modules_list[i].name);
1064 if (ret < 0) {
1065 perror("snprintf modprobe --remove");
1066 goto error;
1067 }
1068 modprobe[sizeof(modprobe) - 1] = '\0';
1069 ret = system(modprobe);
1070 if (ret == -1) {
1071 ERR("Unable to launch modprobe --remove for module %s",
1072 kernel_modules_list[i].name);
1073 } else if (kernel_modules_list[i].required
1074 && WEXITSTATUS(ret) != 0) {
1075 ERR("Unable to remove module %s",
1076 kernel_modules_list[i].name);
1077 } else {
1078 DBG("Modprobe removal successful %s",
1079 kernel_modules_list[i].name);
1080 }
1081 }
1082
1083 error:
1084 return ret;
1085 }
1086
1087 /*
1088 * mount_debugfs
1089 */
1090 static int mount_debugfs(char *path)
1091 {
1092 int ret;
1093 char *type = "debugfs";
1094
1095 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1096 if (ret < 0) {
1097 goto error;
1098 }
1099
1100 ret = mount(type, path, type, 0, NULL);
1101 if (ret < 0) {
1102 perror("mount debugfs");
1103 goto error;
1104 }
1105
1106 DBG("Mounted debugfs successfully at %s", path);
1107
1108 error:
1109 return ret;
1110 }
1111
1112 /*
1113 * Setup necessary data for kernel tracer action.
1114 */
1115 static void init_kernel_tracer(void)
1116 {
1117 int ret;
1118 char *proc_mounts = "/proc/mounts";
1119 char line[256];
1120 char *debugfs_path = NULL, *lttng_path;
1121 FILE *fp;
1122
1123 /* Detect debugfs */
1124 fp = fopen(proc_mounts, "r");
1125 if (fp == NULL) {
1126 ERR("Unable to probe %s", proc_mounts);
1127 goto error;
1128 }
1129
1130 while (fgets(line, sizeof(line), fp) != NULL) {
1131 if (strstr(line, "debugfs") != NULL) {
1132 /* Remove first string */
1133 strtok(line, " ");
1134 /* Dup string here so we can reuse line later on */
1135 debugfs_path = strdup(strtok(NULL, " "));
1136 DBG("Got debugfs path : %s", debugfs_path);
1137 break;
1138 }
1139 }
1140
1141 fclose(fp);
1142
1143 /* Mount debugfs if needded */
1144 if (debugfs_path == NULL) {
1145 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1146 if (ret < 0) {
1147 perror("asprintf debugfs path");
1148 goto error;
1149 }
1150 ret = mount_debugfs(debugfs_path);
1151 if (ret < 0) {
1152 goto error;
1153 }
1154 }
1155
1156 /* Modprobe lttng kernel modules */
1157 ret = modprobe_kernel_modules();
1158 if (ret < 0) {
1159 goto error;
1160 }
1161
1162 /* Setup lttng kernel path */
1163 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1164 if (ret < 0) {
1165 perror("asprintf lttng path");
1166 goto error;
1167 }
1168
1169 /* Open debugfs lttng */
1170 kernel_tracer_fd = open(lttng_path, O_RDWR);
1171 if (kernel_tracer_fd < 0) {
1172 DBG("Failed to open %s", lttng_path);
1173 goto error;
1174 }
1175
1176 free(lttng_path);
1177 free(debugfs_path);
1178 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1179 return;
1180
1181 error:
1182 if (lttng_path) {
1183 free(lttng_path);
1184 }
1185 if (debugfs_path) {
1186 free(debugfs_path);
1187 }
1188 WARN("No kernel tracer available");
1189 kernel_tracer_fd = 0;
1190 return;
1191 }
1192
1193 /*
1194 * Start tracing by creating trace directory and sending FDs to the kernel
1195 * consumer.
1196 */
1197 static int start_kernel_trace(struct ltt_kernel_session *session)
1198 {
1199 int ret = 0;
1200
1201 if (session->kconsumer_fds_sent == 0) {
1202 /*
1203 * Assign default kernel consumer if no consumer assigned to the kernel
1204 * session. At this point, it's NOT suppose to be 0 but this is an extra
1205 * security check.
1206 */
1207 if (session->consumer_fd == 0) {
1208 session->consumer_fd = kconsumerd_cmd_sock;
1209 }
1210
1211 ret = send_kconsumerd_fds(session);
1212 if (ret < 0) {
1213 ERR("Send kconsumerd fds failed");
1214 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1215 goto error;
1216 }
1217
1218 session->kconsumer_fds_sent = 1;
1219 }
1220
1221 error:
1222 return ret;
1223 }
1224
1225 /*
1226 * Notify kernel thread to update it's pollfd.
1227 */
1228 static int notify_kernel_pollfd(void)
1229 {
1230 int ret;
1231
1232 /* Inform kernel thread of the new kernel channel */
1233 ret = write(kernel_poll_pipe[1], "!", 1);
1234 if (ret < 0) {
1235 perror("write kernel poll pipe");
1236 }
1237
1238 return ret;
1239 }
1240
1241 /*
1242 * Allocate a channel structure and fill it.
1243 */
1244 static struct lttng_channel *init_default_channel(enum lttng_domain_type domain_type,
1245 char *name)
1246 {
1247 struct lttng_channel *chan;
1248
1249 chan = malloc(sizeof(struct lttng_channel));
1250 if (chan == NULL) {
1251 perror("init channel malloc");
1252 goto error;
1253 }
1254
1255 if (snprintf(chan->name, NAME_MAX, "%s", name) < 0) {
1256 perror("snprintf channel name");
1257 goto error;
1258 }
1259
1260 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1261 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1262 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1263
1264 switch (domain_type) {
1265 case LTTNG_DOMAIN_KERNEL:
1266 chan->attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
1267 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1268 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1269 break;
1270 /* TODO: add UST */
1271 default:
1272 goto error; /* Not implemented */
1273 }
1274
1275 return chan;
1276
1277 error:
1278 free(chan);
1279 return NULL;
1280 }
1281
1282 /*
1283 * Create a kernel tracer session then create the default channel.
1284 */
1285 static int create_kernel_session(struct ltt_session *session)
1286 {
1287 int ret;
1288
1289 DBG("Creating kernel session");
1290
1291 ret = kernel_create_session(session, kernel_tracer_fd);
1292 if (ret < 0) {
1293 ret = LTTCOMM_KERN_SESS_FAIL;
1294 goto error;
1295 }
1296
1297 /* Set kernel consumer socket fd */
1298 if (kconsumerd_cmd_sock) {
1299 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
1300 }
1301
1302 ret = asprintf(&session->kernel_session->trace_path, "%s/kernel",
1303 session->path);
1304 if (ret < 0) {
1305 perror("asprintf kernel traces path");
1306 goto error;
1307 }
1308
1309 ret = mkdir_recursive(session->kernel_session->trace_path,
1310 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1311 if (ret < 0) {
1312 if (ret != -EEXIST) {
1313 ERR("Trace directory creation error");
1314 goto error;
1315 }
1316 }
1317
1318 error:
1319 return ret;
1320 }
1321
1322 /*
1323 * Using the session list, filled a lttng_session array to send back to the
1324 * client for session listing.
1325 *
1326 * The session list lock MUST be acquired before calling this function. Use
1327 * lock_session_list() and unlock_session_list().
1328 */
1329 static void list_lttng_sessions(struct lttng_session *sessions)
1330 {
1331 int i = 0;
1332 struct ltt_session *session;
1333
1334 DBG("Getting all available session");
1335 /*
1336 * Iterate over session list and append data after the control struct in
1337 * the buffer.
1338 */
1339 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1340 strncpy(sessions[i].path, session->path, PATH_MAX);
1341 sessions[i].path[PATH_MAX - 1] = '\0';
1342 strncpy(sessions[i].name, session->name, NAME_MAX);
1343 sessions[i].name[NAME_MAX - 1] = '\0';
1344 i++;
1345 }
1346 }
1347
1348 /*
1349 * Fill lttng_channel array of all channels.
1350 */
1351 static void list_lttng_channels(struct ltt_session *session,
1352 struct lttng_channel *channels)
1353 {
1354 int i = 0;
1355 struct ltt_kernel_channel *kchan;
1356
1357 DBG("Listing channels for session %s", session->name);
1358
1359 /* Kernel channels */
1360 if (session->kernel_session != NULL) {
1361 cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) {
1362 /* Copy lttng_channel struct to array */
1363 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1364 channels[i].enabled = kchan->enabled;
1365 i++;
1366 }
1367 }
1368
1369 /* TODO: Missing UST listing */
1370 }
1371
1372 /*
1373 * Fill lttng_event array of all events in the channel.
1374 */
1375 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1376 struct lttng_event *events)
1377 {
1378 /*
1379 * TODO: This is ONLY kernel. Need UST support.
1380 */
1381 int i = 0;
1382 struct ltt_kernel_event *event;
1383
1384 DBG("Listing events for channel %s", kchan->channel->name);
1385
1386 /* Kernel channels */
1387 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1388 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1389 events[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1390 events[i].enabled = event->enabled;
1391 switch (event->event->instrumentation) {
1392 case LTTNG_KERNEL_TRACEPOINT:
1393 events[i].type = LTTNG_EVENT_TRACEPOINT;
1394 break;
1395 case LTTNG_KERNEL_KPROBE:
1396 case LTTNG_KERNEL_KRETPROBE:
1397 events[i].type = LTTNG_EVENT_PROBE;
1398 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1399 sizeof(struct lttng_kernel_kprobe));
1400 break;
1401 case LTTNG_KERNEL_FUNCTION:
1402 events[i].type = LTTNG_EVENT_FUNCTION;
1403 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1404 sizeof(struct lttng_kernel_function));
1405 break;
1406 }
1407 i++;
1408 }
1409 }
1410
1411 /*
1412 * Process the command requested by the lttng client within the command
1413 * context structure. This function make sure that the return structure (llm)
1414 * is set and ready for transmission before returning.
1415 *
1416 * Return any error encountered or 0 for success.
1417 */
1418 static int process_client_msg(struct command_ctx *cmd_ctx)
1419 {
1420 int ret = LTTCOMM_OK;
1421
1422 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1423
1424 /*
1425 * Commands that DO NOT need a session.
1426 */
1427 switch (cmd_ctx->lsm->cmd_type) {
1428 case LTTNG_CREATE_SESSION:
1429 case LTTNG_LIST_SESSIONS:
1430 case LTTNG_LIST_TRACEPOINTS:
1431 case LTTNG_CALIBRATE:
1432 break;
1433 default:
1434 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
1435 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session.name);
1436 if (cmd_ctx->session == NULL) {
1437 /* If session name not found */
1438 if (cmd_ctx->lsm->session.name != NULL) {
1439 ret = LTTCOMM_SESS_NOT_FOUND;
1440 } else { /* If no session name specified */
1441 ret = LTTCOMM_SELECT_SESS;
1442 }
1443 goto error;
1444 } else {
1445 /* Acquire lock for the session */
1446 lock_session(cmd_ctx->session);
1447 }
1448 break;
1449 }
1450
1451 /*
1452 * Check domain type for specific "pre-action".
1453 */
1454 switch (cmd_ctx->lsm->domain.type) {
1455 case LTTNG_DOMAIN_KERNEL:
1456 /* Kernel tracer check */
1457 if (kernel_tracer_fd == 0) {
1458 init_kernel_tracer();
1459 if (kernel_tracer_fd == 0) {
1460 ret = LTTCOMM_KERN_NA;
1461 goto error;
1462 }
1463 }
1464
1465 /* Need a session for kernel command */
1466 switch (cmd_ctx->lsm->cmd_type) {
1467 case LTTNG_CALIBRATE:
1468 case LTTNG_CREATE_SESSION:
1469 case LTTNG_LIST_SESSIONS:
1470 case LTTNG_LIST_TRACEPOINTS:
1471 break;
1472 default:
1473 if (cmd_ctx->session->kernel_session == NULL) {
1474 ret = create_kernel_session(cmd_ctx->session);
1475 if (ret < 0) {
1476 ret = LTTCOMM_KERN_SESS_FAIL;
1477 goto error;
1478 }
1479
1480 /* Start the kernel consumer daemon */
1481
1482 if (kconsumerd_pid == 0 &&
1483 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
1484 ret = start_kconsumerd();
1485 if (ret < 0) {
1486 goto error;
1487 }
1488 }
1489 }
1490 }
1491 break;
1492 default:
1493 break;
1494 }
1495
1496 /* Process by command type */
1497 switch (cmd_ctx->lsm->cmd_type) {
1498 case LTTNG_ADD_CONTEXT:
1499 {
1500 struct lttng_kernel_context kctx;
1501
1502 /* Setup lttng message with no payload */
1503 ret = setup_lttng_msg(cmd_ctx, 0);
1504 if (ret < 0) {
1505 goto setup_error;
1506 }
1507
1508 switch (cmd_ctx->lsm->domain.type) {
1509 case LTTNG_DOMAIN_KERNEL:
1510 /* Create Kernel context */
1511 kctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1512 kctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1513 kctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1514 strncpy(kctx.u.perf_counter.name,
1515 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1516 LTTNG_SYMBOL_NAME_LEN);
1517 kctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1518
1519 /* Add kernel context to kernel tracer. See context.c */
1520 ret = add_kernel_context(cmd_ctx->session->kernel_session, &kctx,
1521 cmd_ctx->lsm->u.context.event_name,
1522 cmd_ctx->lsm->u.context.channel_name);
1523 if (ret != LTTCOMM_OK) {
1524 goto error;
1525 }
1526 break;
1527 default:
1528 /* TODO: Userspace tracing */
1529 ret = LTTCOMM_NOT_IMPLEMENTED;
1530 goto error;
1531 }
1532
1533 ret = LTTCOMM_OK;
1534 break;
1535 }
1536 case LTTNG_DISABLE_CHANNEL:
1537 {
1538 struct ltt_kernel_channel *kchan;
1539
1540 /* Setup lttng message with no payload */
1541 ret = setup_lttng_msg(cmd_ctx, 0);
1542 if (ret < 0) {
1543 goto setup_error;
1544 }
1545
1546 switch (cmd_ctx->lsm->domain.type) {
1547 case LTTNG_DOMAIN_KERNEL:
1548 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1549 cmd_ctx->session->kernel_session);
1550 if (kchan == NULL) {
1551 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1552 goto error;
1553 } else if (kchan->enabled == 1) {
1554 ret = kernel_disable_channel(kchan);
1555 if (ret < 0) {
1556 if (ret != EEXIST) {
1557 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1558 }
1559 goto error;
1560 }
1561 }
1562 kernel_wait_quiescent(kernel_tracer_fd);
1563 break;
1564 default:
1565 /* TODO: Userspace tracing */
1566 ret = LTTCOMM_NOT_IMPLEMENTED;
1567 goto error;
1568 }
1569
1570 ret = LTTCOMM_OK;
1571 break;
1572 }
1573 case LTTNG_DISABLE_EVENT:
1574 {
1575 struct ltt_kernel_channel *kchan;
1576 struct ltt_kernel_event *kevent;
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 switch (cmd_ctx->lsm->domain.type) {
1585 case LTTNG_DOMAIN_KERNEL:
1586 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1587 cmd_ctx->session->kernel_session);
1588 if (kchan == NULL) {
1589 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1590 goto error;
1591 }
1592
1593 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, kchan);
1594 if (kevent != NULL) {
1595 DBG("Disabling kernel event %s for channel %s.", kevent->event->name,
1596 kchan->channel->name);
1597 ret = kernel_disable_event(kevent);
1598 if (ret < 0) {
1599 ret = LTTCOMM_KERN_ENABLE_FAIL;
1600 goto error;
1601 }
1602 }
1603
1604 kernel_wait_quiescent(kernel_tracer_fd);
1605 break;
1606 default:
1607 /* TODO: Userspace tracing */
1608 ret = LTTCOMM_NOT_IMPLEMENTED;
1609 goto error;
1610 }
1611
1612 ret = LTTCOMM_OK;
1613 break;
1614 }
1615 case LTTNG_DISABLE_ALL_EVENT:
1616 {
1617 struct ltt_kernel_channel *kchan;
1618 struct ltt_kernel_event *kevent;
1619
1620 /* Setup lttng message with no payload */
1621 ret = setup_lttng_msg(cmd_ctx, 0);
1622 if (ret < 0) {
1623 goto setup_error;
1624 }
1625
1626 switch (cmd_ctx->lsm->domain.type) {
1627 case LTTNG_DOMAIN_KERNEL:
1628 DBG("Disabling all enabled kernel events");
1629 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1630 cmd_ctx->session->kernel_session);
1631 if (kchan == NULL) {
1632 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1633 goto error;
1634 }
1635
1636 /* For each event in the kernel session */
1637 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1638 DBG("Disabling kernel event %s for channel %s.",
1639 kevent->event->name, kchan->channel->name);
1640 ret = kernel_disable_event(kevent);
1641 if (ret < 0) {
1642 continue;
1643 }
1644 }
1645
1646 /* Quiescent wait after event disable */
1647 kernel_wait_quiescent(kernel_tracer_fd);
1648 break;
1649 default:
1650 /* TODO: Userspace tracing */
1651 ret = LTTCOMM_NOT_IMPLEMENTED;
1652 goto error;
1653 }
1654
1655 ret = LTTCOMM_OK;
1656 break;
1657 }
1658 case LTTNG_ENABLE_CHANNEL:
1659 {
1660 struct ltt_kernel_channel *kchan;
1661
1662 /* Setup lttng message with no payload */
1663 ret = setup_lttng_msg(cmd_ctx, 0);
1664 if (ret < 0) {
1665 goto setup_error;
1666 }
1667
1668 switch (cmd_ctx->lsm->domain.type) {
1669 case LTTNG_DOMAIN_KERNEL:
1670 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1671 cmd_ctx->session->kernel_session);
1672 if (kchan == NULL) {
1673 /* Channel not found, creating it */
1674 DBG("Creating kernel channel");
1675
1676 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1677 &cmd_ctx->lsm->u.channel.chan,
1678 cmd_ctx->session->kernel_session->trace_path);
1679 if (ret < 0) {
1680 ret = LTTCOMM_KERN_CHAN_FAIL;
1681 goto error;
1682 }
1683
1684 /* Notify kernel thread that there is a new channel */
1685 ret = notify_kernel_pollfd();
1686 if (ret < 0) {
1687 ret = LTTCOMM_FATAL;
1688 goto error;
1689 }
1690 } else if (kchan->enabled == 0) {
1691 ret = kernel_enable_channel(kchan);
1692 if (ret < 0) {
1693 if (ret != EEXIST) {
1694 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1695 }
1696 goto error;
1697 }
1698 }
1699
1700 kernel_wait_quiescent(kernel_tracer_fd);
1701 break;
1702 default:
1703 /* TODO: Userspace tracing */
1704 ret = LTTCOMM_NOT_IMPLEMENTED;
1705 goto error;
1706 }
1707
1708 ret = LTTCOMM_OK;
1709 break;
1710 }
1711 case LTTNG_ENABLE_EVENT:
1712 {
1713 char *channel_name;
1714 struct ltt_kernel_channel *kchan;
1715 struct ltt_kernel_event *kevent;
1716 struct lttng_channel *chan;
1717
1718 /* Setup lttng message with no payload */
1719 ret = setup_lttng_msg(cmd_ctx, 0);
1720 if (ret < 0) {
1721 goto setup_error;
1722 }
1723
1724 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1725
1726 switch (cmd_ctx->lsm->domain.type) {
1727 case LTTNG_DOMAIN_KERNEL:
1728 kchan = get_kernel_channel_by_name(channel_name,
1729 cmd_ctx->session->kernel_session);
1730 if (kchan == NULL) {
1731 DBG("Channel not found. Creating channel %s", channel_name);
1732
1733 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
1734 if (chan == NULL) {
1735 ret = LTTCOMM_FATAL;
1736 goto error;
1737 }
1738
1739 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1740 chan, cmd_ctx->session->kernel_session->trace_path);
1741 if (ret < 0) {
1742 ret = LTTCOMM_KERN_CHAN_FAIL;
1743 goto error;
1744 }
1745 kchan = get_kernel_channel_by_name(channel_name,
1746 cmd_ctx->session->kernel_session);
1747 if (kchan == NULL) {
1748 ERR("Channel %s not found after creation. Internal error, giving up.",
1749 channel_name);
1750 ret = LTTCOMM_FATAL;
1751 goto error;
1752 }
1753 }
1754
1755 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
1756 if (kevent == NULL) {
1757 DBG("Creating kernel event %s for channel %s.",
1758 cmd_ctx->lsm->u.enable.event.name, channel_name);
1759 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
1760 } else {
1761 DBG("Enabling kernel event %s for channel %s.",
1762 kevent->event->name, channel_name);
1763 ret = kernel_enable_event(kevent);
1764 if (ret == -EEXIST) {
1765 ret = LTTCOMM_KERN_EVENT_EXIST;
1766 goto error;
1767 }
1768 }
1769
1770 if (ret < 0) {
1771 ret = LTTCOMM_KERN_ENABLE_FAIL;
1772 goto error;
1773 }
1774
1775 kernel_wait_quiescent(kernel_tracer_fd);
1776 break;
1777 default:
1778 /* TODO: Userspace tracing */
1779 ret = LTTCOMM_NOT_IMPLEMENTED;
1780 goto error;
1781 }
1782 ret = LTTCOMM_OK;
1783 break;
1784 }
1785 case LTTNG_ENABLE_ALL_EVENT:
1786 {
1787 int size, i;
1788 char *channel_name;
1789 struct ltt_kernel_channel *kchan;
1790 struct ltt_kernel_event *kevent;
1791 struct lttng_event *event_list;
1792 struct lttng_channel *chan;
1793
1794 /* Setup lttng message with no payload */
1795 ret = setup_lttng_msg(cmd_ctx, 0);
1796 if (ret < 0) {
1797 goto setup_error;
1798 }
1799
1800 DBG("Enabling all kernel event");
1801
1802 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1803
1804 switch (cmd_ctx->lsm->domain.type) {
1805 case LTTNG_DOMAIN_KERNEL:
1806 kchan = get_kernel_channel_by_name(channel_name,
1807 cmd_ctx->session->kernel_session);
1808 if (kchan == NULL) {
1809 DBG("Channel not found. Creating channel %s", channel_name);
1810
1811 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
1812 if (chan == NULL) {
1813 ret = LTTCOMM_FATAL;
1814 goto error;
1815 }
1816
1817 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1818 chan, cmd_ctx->session->kernel_session->trace_path);
1819 if (ret < 0) {
1820 ret = LTTCOMM_KERN_CHAN_FAIL;
1821 goto error;
1822 }
1823 kchan = get_kernel_channel_by_name(channel_name,
1824 cmd_ctx->session->kernel_session);
1825 if (kchan == NULL) {
1826 ERR("Channel %s not found after creation. Internal error, giving up.",
1827 channel_name);
1828 ret = LTTCOMM_FATAL;
1829 goto error;
1830 }
1831 }
1832
1833 /* For each event in the kernel session */
1834 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1835 DBG("Enabling kernel event %s for channel %s.",
1836 kevent->event->name, channel_name);
1837 ret = kernel_enable_event(kevent);
1838 if (ret < 0) {
1839 continue;
1840 }
1841 }
1842
1843 size = kernel_list_events(kernel_tracer_fd, &event_list);
1844 if (size < 0) {
1845 ret = LTTCOMM_KERN_LIST_FAIL;
1846 goto error;
1847 }
1848
1849 for (i = 0; i < size; i++) {
1850 kevent = get_kernel_event_by_name(event_list[i].name, kchan);
1851 if (kevent == NULL) {
1852 /* Default event type for enable all */
1853 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
1854 /* Enable each single tracepoint event */
1855 ret = kernel_create_event(&event_list[i], kchan);
1856 if (ret < 0) {
1857 /* Ignore error here and continue */
1858 }
1859 }
1860 }
1861
1862 free(event_list);
1863
1864 /* Quiescent wait after event enable */
1865 kernel_wait_quiescent(kernel_tracer_fd);
1866 break;
1867 default:
1868 /* TODO: Userspace tracing */
1869 ret = LTTCOMM_NOT_IMPLEMENTED;
1870 goto error;
1871 }
1872
1873 ret = LTTCOMM_OK;
1874 break;
1875 }
1876 case LTTNG_LIST_TRACEPOINTS:
1877 {
1878 struct lttng_event *events;
1879 ssize_t nb_events = 0;
1880
1881 switch (cmd_ctx->lsm->domain.type) {
1882 case LTTNG_DOMAIN_KERNEL:
1883 DBG("Listing kernel events");
1884 nb_events = kernel_list_events(kernel_tracer_fd, &events);
1885 if (nb_events < 0) {
1886 ret = LTTCOMM_KERN_LIST_FAIL;
1887 goto error;
1888 }
1889 break;
1890 default:
1891 /* TODO: Userspace listing */
1892 ret = LTTCOMM_NOT_IMPLEMENTED;
1893 break;
1894 }
1895
1896 /*
1897 * Setup lttng message with payload size set to the event list size in
1898 * bytes and then copy list into the llm payload.
1899 */
1900 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
1901 if (ret < 0) {
1902 free(events);
1903 goto setup_error;
1904 }
1905
1906 /* Copy event list into message payload */
1907 memcpy(cmd_ctx->llm->payload, events,
1908 sizeof(struct lttng_event) * nb_events);
1909
1910 free(events);
1911
1912 ret = LTTCOMM_OK;
1913 break;
1914 }
1915 case LTTNG_START_TRACE:
1916 {
1917 struct ltt_kernel_channel *chan;
1918
1919 /* Setup lttng message with no payload */
1920 ret = setup_lttng_msg(cmd_ctx, 0);
1921 if (ret < 0) {
1922 goto setup_error;
1923 }
1924
1925 /* Kernel tracing */
1926 if (cmd_ctx->session->kernel_session != NULL) {
1927 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1928 DBG("Open kernel metadata");
1929 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1930 cmd_ctx->session->kernel_session->trace_path);
1931 if (ret < 0) {
1932 ret = LTTCOMM_KERN_META_FAIL;
1933 goto error;
1934 }
1935 }
1936
1937 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1938 DBG("Opening kernel metadata stream");
1939 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1940 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1941 if (ret < 0) {
1942 ERR("Kernel create metadata stream failed");
1943 ret = LTTCOMM_KERN_STREAM_FAIL;
1944 goto error;
1945 }
1946 }
1947 }
1948
1949 /* For each channel */
1950 cds_list_for_each_entry(chan,
1951 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1952 if (chan->stream_count == 0) {
1953 ret = kernel_open_channel_stream(chan);
1954 if (ret < 0) {
1955 ERR("Kernel create channel stream failed");
1956 ret = LTTCOMM_KERN_STREAM_FAIL;
1957 goto error;
1958 }
1959 /* Update the stream global counter */
1960 cmd_ctx->session->kernel_session->stream_count_global += ret;
1961 }
1962 }
1963
1964 DBG("Start kernel tracing");
1965 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1966 if (ret < 0) {
1967 ERR("Kernel start session failed");
1968 ret = LTTCOMM_KERN_START_FAIL;
1969 goto error;
1970 }
1971
1972 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1973 if (ret < 0) {
1974 ret = LTTCOMM_KERN_START_FAIL;
1975 goto error;
1976 }
1977
1978 /* Quiescent wait after starting trace */
1979 kernel_wait_quiescent(kernel_tracer_fd);
1980 }
1981
1982 /* TODO: Start all UST traces */
1983
1984 ret = LTTCOMM_OK;
1985 break;
1986 }
1987 case LTTNG_STOP_TRACE:
1988 {
1989 struct ltt_kernel_channel *chan;
1990 /* Setup lttng message with no payload */
1991 ret = setup_lttng_msg(cmd_ctx, 0);
1992 if (ret < 0) {
1993 goto setup_error;
1994 }
1995
1996 /* Kernel tracer */
1997 if (cmd_ctx->session->kernel_session != NULL) {
1998 DBG("Stop kernel tracing");
1999
2000 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
2001 if (ret < 0) {
2002 ERR("Kernel metadata flush failed");
2003 }
2004
2005 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
2006 ret = kernel_flush_buffer(chan);
2007 if (ret < 0) {
2008 ERR("Kernel flush buffer error");
2009 }
2010 }
2011
2012 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
2013 if (ret < 0) {
2014 ERR("Kernel stop session failed");
2015 ret = LTTCOMM_KERN_STOP_FAIL;
2016 goto error;
2017 }
2018
2019 /* Quiescent wait after stopping trace */
2020 kernel_wait_quiescent(kernel_tracer_fd);
2021 }
2022
2023 /* TODO : User-space tracer */
2024
2025 ret = LTTCOMM_OK;
2026 break;
2027 }
2028 case LTTNG_CREATE_SESSION:
2029 {
2030 /* Setup lttng message with no payload */
2031 ret = setup_lttng_msg(cmd_ctx, 0);
2032 if (ret < 0) {
2033 goto setup_error;
2034 }
2035
2036 ret = create_session(cmd_ctx->lsm->session.name, cmd_ctx->lsm->session.path);
2037 if (ret < 0) {
2038 if (ret == -EEXIST) {
2039 ret = LTTCOMM_EXIST_SESS;
2040 } else {
2041 ret = LTTCOMM_FATAL;
2042 }
2043 goto error;
2044 }
2045
2046 ret = LTTCOMM_OK;
2047 break;
2048 }
2049 case LTTNG_DESTROY_SESSION:
2050 {
2051 /* Setup lttng message with no payload */
2052 ret = setup_lttng_msg(cmd_ctx, 0);
2053 if (ret < 0) {
2054 goto setup_error;
2055 }
2056
2057 /* Clean kernel session teardown */
2058 teardown_kernel_session(cmd_ctx->session);
2059
2060 ret = destroy_session(cmd_ctx->lsm->session.name);
2061 if (ret < 0) {
2062 ret = LTTCOMM_FATAL;
2063 goto error;
2064 }
2065
2066 /*
2067 * Must notify the kernel thread here to update it's pollfd in order to
2068 * remove the channel(s)' fd just destroyed.
2069 */
2070 ret = notify_kernel_pollfd();
2071 if (ret < 0) {
2072 ret = LTTCOMM_FATAL;
2073 goto error;
2074 }
2075
2076 ret = LTTCOMM_OK;
2077 break;
2078 }
2079 case LTTNG_LIST_DOMAINS:
2080 {
2081 size_t nb_dom = 0;
2082
2083 if (cmd_ctx->session->kernel_session != NULL) {
2084 nb_dom++;
2085 }
2086
2087 nb_dom += cmd_ctx->session->ust_trace_count;
2088
2089 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_domain) * nb_dom);
2090 if (ret < 0) {
2091 goto setup_error;
2092 }
2093
2094 ((struct lttng_domain *)(cmd_ctx->llm->payload))[0].type =
2095 LTTNG_DOMAIN_KERNEL;
2096
2097 /* TODO: User-space tracer domain support */
2098 ret = LTTCOMM_OK;
2099 break;
2100 }
2101 case LTTNG_LIST_CHANNELS:
2102 {
2103 /*
2104 * TODO: Only kernel channels are listed here. UST listing
2105 * is needed on lttng-ust 2.0 release.
2106 */
2107 size_t nb_chan = 0;
2108 if (cmd_ctx->session->kernel_session != NULL) {
2109 nb_chan += cmd_ctx->session->kernel_session->channel_count;
2110 }
2111
2112 ret = setup_lttng_msg(cmd_ctx,
2113 sizeof(struct lttng_channel) * nb_chan);
2114 if (ret < 0) {
2115 goto setup_error;
2116 }
2117
2118 list_lttng_channels(cmd_ctx->session,
2119 (struct lttng_channel *)(cmd_ctx->llm->payload));
2120
2121 ret = LTTCOMM_OK;
2122 break;
2123 }
2124 case LTTNG_LIST_EVENTS:
2125 {
2126 /*
2127 * TODO: Only kernel events are listed here. UST listing
2128 * is needed on lttng-ust 2.0 release.
2129 */
2130 size_t nb_event = 0;
2131 struct ltt_kernel_channel *kchan = NULL;
2132
2133 if (cmd_ctx->session->kernel_session != NULL) {
2134 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.list.channel_name,
2135 cmd_ctx->session->kernel_session);
2136 if (kchan == NULL) {
2137 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2138 goto error;
2139 }
2140 nb_event += kchan->event_count;
2141 }
2142
2143 ret = setup_lttng_msg(cmd_ctx,
2144 sizeof(struct lttng_event) * nb_event);
2145 if (ret < 0) {
2146 goto setup_error;
2147 }
2148
2149 DBG("Listing events (%zu events)", nb_event);
2150
2151 list_lttng_events(kchan,
2152 (struct lttng_event *)(cmd_ctx->llm->payload));
2153
2154 ret = LTTCOMM_OK;
2155 break;
2156 }
2157 case LTTNG_LIST_SESSIONS:
2158 {
2159 lock_session_list();
2160
2161 if (session_list_ptr->count == 0) {
2162 ret = LTTCOMM_NO_SESSION;
2163 unlock_session_list();
2164 goto error;
2165 }
2166
2167 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
2168 session_list_ptr->count);
2169 if (ret < 0) {
2170 unlock_session_list();
2171 goto setup_error;
2172 }
2173
2174 /* Filled the session array */
2175 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
2176
2177 unlock_session_list();
2178
2179 ret = LTTCOMM_OK;
2180 break;
2181 }
2182 case LTTNG_CALIBRATE:
2183 {
2184 /* Setup lttng message with no payload */
2185 ret = setup_lttng_msg(cmd_ctx, 0);
2186 if (ret < 0) {
2187 goto setup_error;
2188 }
2189
2190 switch (cmd_ctx->lsm->domain.type) {
2191 case LTTNG_DOMAIN_KERNEL:
2192 {
2193 struct lttng_kernel_calibrate kcalibrate;
2194
2195 kcalibrate.type = cmd_ctx->lsm->u.calibrate.type;
2196 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2197 if (ret < 0) {
2198 ret = LTTCOMM_KERN_ENABLE_FAIL;
2199 goto error;
2200 }
2201 break;
2202 }
2203 default:
2204 /* TODO: Userspace tracing */
2205 ret = LTTCOMM_NOT_IMPLEMENTED;
2206 goto error;
2207 }
2208 ret = LTTCOMM_OK;
2209 break;
2210 }
2211 case LTTNG_REGISTER_CONSUMER:
2212 {
2213 int sock;
2214
2215 /* Setup lttng message with no payload */
2216 ret = setup_lttng_msg(cmd_ctx, 0);
2217 if (ret < 0) {
2218 goto setup_error;
2219 }
2220
2221 switch (cmd_ctx->lsm->domain.type) {
2222 case LTTNG_DOMAIN_KERNEL:
2223 {
2224 /* Can't register a consumer if there is already one */
2225 if (cmd_ctx->session->kernel_session->consumer_fd != 0) {
2226 ret = LTTCOMM_CONNECT_FAIL;
2227 goto error;
2228 }
2229
2230 sock = lttcomm_connect_unix_sock(cmd_ctx->lsm->u.reg.path);
2231 if (sock < 0) {
2232 ret = LTTCOMM_CONNECT_FAIL;
2233 goto error;
2234 }
2235
2236 cmd_ctx->session->kernel_session->consumer_fd = sock;
2237 break;
2238 }
2239 default:
2240 /* TODO: Userspace tracing */
2241 ret = LTTCOMM_NOT_IMPLEMENTED;
2242 goto error;
2243 }
2244
2245 ret = LTTCOMM_OK;
2246 break;
2247 }
2248
2249 default:
2250 /* Undefined command */
2251 ret = setup_lttng_msg(cmd_ctx, 0);
2252 if (ret < 0) {
2253 goto setup_error;
2254 }
2255
2256 ret = LTTCOMM_UND;
2257 break;
2258 }
2259
2260 /* Set return code */
2261 cmd_ctx->llm->ret_code = ret;
2262
2263 if (cmd_ctx->session) {
2264 unlock_session(cmd_ctx->session);
2265 }
2266
2267 return ret;
2268
2269 error:
2270 if (cmd_ctx->llm == NULL) {
2271 DBG("Missing llm structure. Allocating one.");
2272 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2273 goto setup_error;
2274 }
2275 }
2276 /* Notify client of error */
2277 cmd_ctx->llm->ret_code = ret;
2278
2279 setup_error:
2280 if (cmd_ctx->session) {
2281 unlock_session(cmd_ctx->session);
2282 }
2283 return ret;
2284 }
2285
2286 /*
2287 * This thread manage all clients request using the unix client socket for
2288 * communication.
2289 */
2290 static void *thread_manage_clients(void *data)
2291 {
2292 int sock = 0, ret;
2293 struct command_ctx *cmd_ctx = NULL;
2294 struct pollfd pollfd[2];
2295
2296 DBG("[thread] Manage client started");
2297
2298 ret = lttcomm_listen_unix_sock(client_sock);
2299 if (ret < 0) {
2300 goto error;
2301 }
2302
2303 /* First fd is always the quit pipe */
2304 pollfd[0].fd = thread_quit_pipe[0];
2305
2306 /* Apps socket */
2307 pollfd[1].fd = client_sock;
2308 pollfd[1].events = POLLIN;
2309
2310 /* Notify parent pid that we are ready
2311 * to accept command for client side.
2312 */
2313 if (opt_sig_parent) {
2314 kill(ppid, SIGCHLD);
2315 }
2316
2317 while (1) {
2318 DBG("Accepting client command ...");
2319
2320 /* Inifinite blocking call, waiting for transmission */
2321 ret = poll(pollfd, 2, -1);
2322 if (ret < 0) {
2323 perror("poll client thread");
2324 goto error;
2325 }
2326
2327 /* Thread quit pipe has been closed. Killing thread. */
2328 if (pollfd[0].revents == POLLNVAL) {
2329 goto error;
2330 } else if (pollfd[1].revents == POLLERR) {
2331 ERR("Client socket poll error");
2332 goto error;
2333 }
2334
2335 sock = lttcomm_accept_unix_sock(client_sock);
2336 if (sock < 0) {
2337 goto error;
2338 }
2339
2340 /* Allocate context command to process the client request */
2341 cmd_ctx = malloc(sizeof(struct command_ctx));
2342
2343 /* Allocate data buffer for reception */
2344 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2345 cmd_ctx->llm = NULL;
2346 cmd_ctx->session = NULL;
2347
2348 /*
2349 * Data is received from the lttng client. The struct
2350 * lttcomm_session_msg (lsm) contains the command and data request of
2351 * the client.
2352 */
2353 DBG("Receiving data from client ...");
2354 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2355 if (ret <= 0) {
2356 continue;
2357 }
2358
2359 // TODO: Validate cmd_ctx including sanity check for security purpose.
2360
2361 /*
2362 * This function dispatch the work to the kernel or userspace tracer
2363 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2364 * informations for the client. The command context struct contains
2365 * everything this function may needs.
2366 */
2367 ret = process_client_msg(cmd_ctx);
2368 if (ret < 0) {
2369 /* TODO: Inform client somehow of the fatal error. At this point,
2370 * ret < 0 means that a malloc failed (ENOMEM). */
2371 /* Error detected but still accept command */
2372 clean_command_ctx(&cmd_ctx);
2373 continue;
2374 }
2375
2376 DBG("Sending response (size: %d, retcode: %d)",
2377 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2378 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2379 if (ret < 0) {
2380 ERR("Failed to send data back to client");
2381 }
2382
2383 clean_command_ctx(&cmd_ctx);
2384
2385 /* End of transmission */
2386 close(sock);
2387 }
2388
2389 error:
2390 DBG("Client thread dying");
2391 if (client_sock) {
2392 close(client_sock);
2393 }
2394 if (sock) {
2395 close(sock);
2396 }
2397
2398 unlink(client_unix_sock_path);
2399
2400 clean_command_ctx(&cmd_ctx);
2401 return NULL;
2402 }
2403
2404
2405 /*
2406 * usage function on stderr
2407 */
2408 static void usage(void)
2409 {
2410 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2411 fprintf(stderr, " -h, --help Display this usage.\n");
2412 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2413 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2414 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2415 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2416 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2417 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2418 fprintf(stderr, " -V, --version Show version number.\n");
2419 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2420 fprintf(stderr, " -q, --quiet No output at all.\n");
2421 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2422 fprintf(stderr, " --verbose-kconsumerd Verbose mode for kconsumerd. Activate DBG() macro.\n");
2423 }
2424
2425 /*
2426 * daemon argument parsing
2427 */
2428 static int parse_args(int argc, char **argv)
2429 {
2430 int c;
2431
2432 static struct option long_options[] = {
2433 { "client-sock", 1, 0, 'c' },
2434 { "apps-sock", 1, 0, 'a' },
2435 { "kconsumerd-cmd-sock", 1, 0, 0 },
2436 { "kconsumerd-err-sock", 1, 0, 0 },
2437 { "daemonize", 0, 0, 'd' },
2438 { "sig-parent", 0, 0, 'S' },
2439 { "help", 0, 0, 'h' },
2440 { "group", 1, 0, 'g' },
2441 { "version", 0, 0, 'V' },
2442 { "quiet", 0, 0, 'q' },
2443 { "verbose", 0, 0, 'v' },
2444 { "verbose-kconsumerd", 0, 0, 'Z' },
2445 { NULL, 0, 0, 0 }
2446 };
2447
2448 while (1) {
2449 int option_index = 0;
2450 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:Z", long_options, &option_index);
2451 if (c == -1) {
2452 break;
2453 }
2454
2455 switch (c) {
2456 case 0:
2457 fprintf(stderr, "option %s", long_options[option_index].name);
2458 if (optarg) {
2459 fprintf(stderr, " with arg %s\n", optarg);
2460 }
2461 break;
2462 case 'c':
2463 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2464 break;
2465 case 'a':
2466 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2467 break;
2468 case 'd':
2469 opt_daemon = 1;
2470 break;
2471 case 'g':
2472 opt_tracing_group = strdup(optarg);
2473 break;
2474 case 'h':
2475 usage();
2476 exit(EXIT_FAILURE);
2477 case 'V':
2478 fprintf(stdout, "%s\n", VERSION);
2479 exit(EXIT_SUCCESS);
2480 case 'S':
2481 opt_sig_parent = 1;
2482 break;
2483 case 'E':
2484 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2485 break;
2486 case 'C':
2487 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2488 break;
2489 case 'q':
2490 opt_quiet = 1;
2491 break;
2492 case 'v':
2493 /* Verbose level can increase using multiple -v */
2494 opt_verbose += 1;
2495 break;
2496 case 'Z':
2497 opt_verbose_kconsumerd += 1;
2498 break;
2499 default:
2500 /* Unknown option or other error.
2501 * Error is printed by getopt, just return */
2502 return -1;
2503 }
2504 }
2505
2506 return 0;
2507 }
2508
2509 /*
2510 * Creates the two needed socket by the daemon.
2511 * apps_sock - The communication socket for all UST apps.
2512 * client_sock - The communication of the cli tool (lttng).
2513 */
2514 static int init_daemon_socket(void)
2515 {
2516 int ret = 0;
2517 mode_t old_umask;
2518
2519 old_umask = umask(0);
2520
2521 /* Create client tool unix socket */
2522 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2523 if (client_sock < 0) {
2524 ERR("Create unix sock failed: %s", client_unix_sock_path);
2525 ret = -1;
2526 goto end;
2527 }
2528
2529 /* File permission MUST be 660 */
2530 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2531 if (ret < 0) {
2532 ERR("Set file permissions failed: %s", client_unix_sock_path);
2533 perror("chmod");
2534 goto end;
2535 }
2536
2537 /* Create the application unix socket */
2538 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2539 if (apps_sock < 0) {
2540 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2541 ret = -1;
2542 goto end;
2543 }
2544
2545 /* File permission MUST be 666 */
2546 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2547 if (ret < 0) {
2548 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2549 perror("chmod");
2550 goto end;
2551 }
2552
2553 end:
2554 umask(old_umask);
2555 return ret;
2556 }
2557
2558 /*
2559 * Check if the global socket is available, and if a daemon is answering
2560 * at the other side. If yes, error is returned.
2561 */
2562 static int check_existing_daemon(void)
2563 {
2564 if (access(client_unix_sock_path, F_OK) < 0 &&
2565 access(apps_unix_sock_path, F_OK) < 0)
2566 return 0;
2567 /* Is there anybody out there ? */
2568 if (lttng_session_daemon_alive())
2569 return -EEXIST;
2570 else
2571 return 0;
2572 }
2573
2574 /*
2575 * Set the tracing group gid onto the client socket.
2576 *
2577 * Race window between mkdir and chown is OK because we are going from more
2578 * permissive (root.root) to les permissive (root.tracing).
2579 */
2580 static int set_permissions(void)
2581 {
2582 int ret;
2583 gid_t gid;
2584
2585 gid = allowed_group();
2586 if (gid < 0) {
2587 if (is_root) {
2588 WARN("No tracing group detected");
2589 ret = 0;
2590 } else {
2591 ERR("Missing tracing group. Aborting execution.");
2592 ret = -1;
2593 }
2594 goto end;
2595 }
2596
2597 /* Set lttng run dir */
2598 ret = chown(LTTNG_RUNDIR, 0, gid);
2599 if (ret < 0) {
2600 ERR("Unable to set group on " LTTNG_RUNDIR);
2601 perror("chown");
2602 }
2603
2604 /* lttng client socket path */
2605 ret = chown(client_unix_sock_path, 0, gid);
2606 if (ret < 0) {
2607 ERR("Unable to set group on %s", client_unix_sock_path);
2608 perror("chown");
2609 }
2610
2611 /* kconsumerd error socket path */
2612 ret = chown(kconsumerd_err_unix_sock_path, 0, gid);
2613 if (ret < 0) {
2614 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2615 perror("chown");
2616 }
2617
2618 DBG("All permissions are set");
2619
2620 end:
2621 return ret;
2622 }
2623
2624 /*
2625 * Create the pipe used to wake up the kernel thread.
2626 */
2627 static int create_kernel_poll_pipe(void)
2628 {
2629 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2630 }
2631
2632 /*
2633 * Create the lttng run directory needed for all global sockets and pipe.
2634 */
2635 static int create_lttng_rundir(void)
2636 {
2637 int ret;
2638
2639 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2640 if (ret < 0) {
2641 if (errno != EEXIST) {
2642 ERR("Unable to create " LTTNG_RUNDIR);
2643 goto error;
2644 } else {
2645 ret = 0;
2646 }
2647 }
2648
2649 error:
2650 return ret;
2651 }
2652
2653 /*
2654 * Setup sockets and directory needed by the kconsumerd communication with the
2655 * session daemon.
2656 */
2657 static int set_kconsumerd_sockets(void)
2658 {
2659 int ret;
2660
2661 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2662 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2663 }
2664
2665 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2666 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2667 }
2668
2669 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2670 if (ret < 0) {
2671 if (errno != EEXIST) {
2672 ERR("Failed to create " KCONSUMERD_PATH);
2673 goto error;
2674 }
2675 ret = 0;
2676 }
2677
2678 /* Create the kconsumerd error unix socket */
2679 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2680 if (kconsumerd_err_sock < 0) {
2681 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2682 ret = -1;
2683 goto error;
2684 }
2685
2686 /* File permission MUST be 660 */
2687 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2688 if (ret < 0) {
2689 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2690 perror("chmod");
2691 goto error;
2692 }
2693
2694 error:
2695 return ret;
2696 }
2697
2698 /*
2699 * Signal handler for the daemon
2700 *
2701 * Simply stop all worker threads, leaving main() return gracefully
2702 * after joining all threads and calling cleanup().
2703 */
2704 static void sighandler(int sig)
2705 {
2706 switch (sig) {
2707 case SIGPIPE:
2708 DBG("SIGPIPE catched");
2709 return;
2710 case SIGINT:
2711 DBG("SIGINT catched");
2712 stop_threads();
2713 break;
2714 case SIGTERM:
2715 DBG("SIGTERM catched");
2716 stop_threads();
2717 break;
2718 default:
2719 break;
2720 }
2721 }
2722
2723 /*
2724 * Setup signal handler for :
2725 * SIGINT, SIGTERM, SIGPIPE
2726 */
2727 static int set_signal_handler(void)
2728 {
2729 int ret = 0;
2730 struct sigaction sa;
2731 sigset_t sigset;
2732
2733 if ((ret = sigemptyset(&sigset)) < 0) {
2734 perror("sigemptyset");
2735 return ret;
2736 }
2737
2738 sa.sa_handler = sighandler;
2739 sa.sa_mask = sigset;
2740 sa.sa_flags = 0;
2741 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2742 perror("sigaction");
2743 return ret;
2744 }
2745
2746 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2747 perror("sigaction");
2748 return ret;
2749 }
2750
2751 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2752 perror("sigaction");
2753 return ret;
2754 }
2755
2756 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2757
2758 return ret;
2759 }
2760
2761 /*
2762 * Set open files limit to unlimited. This daemon can open a large number of
2763 * file descriptors in order to consumer multiple kernel traces.
2764 */
2765 static void set_ulimit(void)
2766 {
2767 int ret;
2768 struct rlimit lim;
2769
2770 /* The kernel does not allowed an infinite limit for open files */
2771 lim.rlim_cur = 65535;
2772 lim.rlim_max = 65535;
2773
2774 ret = setrlimit(RLIMIT_NOFILE, &lim);
2775 if (ret < 0) {
2776 perror("failed to set open files limit");
2777 }
2778 }
2779
2780 /*
2781 * main
2782 */
2783 int main(int argc, char **argv)
2784 {
2785 int ret = 0;
2786 void *status;
2787 const char *home_path;
2788
2789 /* Create thread quit pipe */
2790 if ((ret = init_thread_quit_pipe()) < 0) {
2791 goto error;
2792 }
2793
2794 /* Parse arguments */
2795 progname = argv[0];
2796 if ((ret = parse_args(argc, argv) < 0)) {
2797 goto error;
2798 }
2799
2800 /* Daemonize */
2801 if (opt_daemon) {
2802 ret = daemon(0, 0);
2803 if (ret < 0) {
2804 perror("daemon");
2805 goto error;
2806 }
2807 }
2808
2809 /* Check if daemon is UID = 0 */
2810 is_root = !getuid();
2811
2812 if (is_root) {
2813 ret = create_lttng_rundir();
2814 if (ret < 0) {
2815 goto error;
2816 }
2817
2818 if (strlen(apps_unix_sock_path) == 0) {
2819 snprintf(apps_unix_sock_path, PATH_MAX,
2820 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2821 }
2822
2823 if (strlen(client_unix_sock_path) == 0) {
2824 snprintf(client_unix_sock_path, PATH_MAX,
2825 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2826 }
2827 } else {
2828 home_path = get_home_dir();
2829 if (home_path == NULL) {
2830 /* TODO: Add --socket PATH option */
2831 ERR("Can't get HOME directory for sockets creation.");
2832 ret = -EPERM;
2833 goto error;
2834 }
2835
2836 if (strlen(apps_unix_sock_path) == 0) {
2837 snprintf(apps_unix_sock_path, PATH_MAX,
2838 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2839 }
2840
2841 /* Set the cli tool unix socket path */
2842 if (strlen(client_unix_sock_path) == 0) {
2843 snprintf(client_unix_sock_path, PATH_MAX,
2844 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2845 }
2846 }
2847
2848 DBG("Client socket path %s", client_unix_sock_path);
2849 DBG("Application socket path %s", apps_unix_sock_path);
2850
2851 /*
2852 * See if daemon already exist.
2853 */
2854 if ((ret = check_existing_daemon()) < 0) {
2855 ERR("Already running daemon.\n");
2856 /*
2857 * We do not goto exit because we must not cleanup()
2858 * because a daemon is already running.
2859 */
2860 goto error;
2861 }
2862
2863 /* After this point, we can safely call cleanup() so goto error is used */
2864
2865 /*
2866 * These actions must be executed as root. We do that *after* setting up
2867 * the sockets path because we MUST make the check for another daemon using
2868 * those paths *before* trying to set the kernel consumer sockets and init
2869 * kernel tracer.
2870 */
2871 if (is_root) {
2872 ret = set_kconsumerd_sockets();
2873 if (ret < 0) {
2874 goto exit;
2875 }
2876
2877 /* Setup kernel tracer */
2878 init_kernel_tracer();
2879
2880 /* Set ulimit for open files */
2881 set_ulimit();
2882 }
2883
2884 if ((ret = set_signal_handler()) < 0) {
2885 goto exit;
2886 }
2887
2888 /* Setup the needed unix socket */
2889 if ((ret = init_daemon_socket()) < 0) {
2890 goto exit;
2891 }
2892
2893 /* Set credentials to socket */
2894 if (is_root && ((ret = set_permissions()) < 0)) {
2895 goto exit;
2896 }
2897
2898 /* Get parent pid if -S, --sig-parent is specified. */
2899 if (opt_sig_parent) {
2900 ppid = getppid();
2901 }
2902
2903 /* Setup the kernel pipe for waking up the kernel thread */
2904 if ((ret = create_kernel_poll_pipe()) < 0) {
2905 goto exit;
2906 }
2907
2908 /*
2909 * Get session list pointer. This pointer MUST NOT be free().
2910 * This list is statically declared in session.c
2911 */
2912 session_list_ptr = get_session_list();
2913
2914 /* Create thread to manage the client socket */
2915 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2916 if (ret != 0) {
2917 perror("pthread_create");
2918 goto exit_client;
2919 }
2920
2921 /* Create thread to manage application socket */
2922 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2923 if (ret != 0) {
2924 perror("pthread_create");
2925 goto exit_apps;
2926 }
2927
2928 /* Create kernel thread to manage kernel event */
2929 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2930 if (ret != 0) {
2931 perror("pthread_create");
2932 goto exit_kernel;
2933 }
2934
2935 ret = pthread_join(kernel_thread, &status);
2936 if (ret != 0) {
2937 perror("pthread_join");
2938 goto error; /* join error, exit without cleanup */
2939 }
2940
2941 exit_kernel:
2942 ret = pthread_join(apps_thread, &status);
2943 if (ret != 0) {
2944 perror("pthread_join");
2945 goto error; /* join error, exit without cleanup */
2946 }
2947
2948 exit_apps:
2949 ret = pthread_join(client_thread, &status);
2950 if (ret != 0) {
2951 perror("pthread_join");
2952 goto error; /* join error, exit without cleanup */
2953 }
2954
2955 ret = join_kconsumerd_thread();
2956 if (ret != 0) {
2957 perror("join_kconsumerd");
2958 goto error; /* join error, exit without cleanup */
2959 }
2960
2961 exit_client:
2962 exit:
2963 /*
2964 * cleanup() is called when no other thread is running.
2965 */
2966 cleanup();
2967 if (!ret)
2968 exit(EXIT_SUCCESS);
2969 error:
2970 exit(EXIT_FAILURE);
2971 }
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