dd9f221de58b9d53c111f2729d50c9317af00e2d
[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/mount.h>
33 #include <sys/resource.h>
34 #include <sys/socket.h>
35 #include <sys/stat.h>
36 #include <sys/types.h>
37 #include <unistd.h>
38
39 #include <ltt-kconsumerd.h>
40 #include <lttng-sessiond-comm.h>
41 #include <lttng/lttng-kconsumerd.h>
42 #include <lttngerr.h>
43
44 #include "context.h"
45 #include "kernel-ctl.h"
46 #include "ltt-sessiond.h"
47 #include "traceable-app.h"
48 #include "ust-ctl.h"
49 #include "utils.h"
50
51 /* Const values */
52 const char default_home_dir[] = DEFAULT_HOME_DIR;
53 const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
54 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
55 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
56
57 /* Variables */
58 int opt_verbose; /* Not static for lttngerr.h */
59 int opt_verbose_kconsumerd; /* Not static for lttngerr.h */
60 int opt_quiet; /* Not static for lttngerr.h */
61
62 const char *progname;
63 const char *opt_tracing_group;
64 static int opt_sig_parent;
65 static int opt_daemon;
66 static int is_root; /* Set to 1 if the daemon is running as root */
67 static pid_t ppid; /* Parent PID for --sig-parent option */
68 static pid_t kconsumerd_pid;
69 static struct pollfd *kernel_pollfd;
70
71 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
72 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
73 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
74 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
75
76 /* Sockets and FDs */
77 static int client_sock;
78 static int apps_sock;
79 static int kconsumerd_err_sock;
80 static int kconsumerd_cmd_sock;
81 static int kernel_tracer_fd;
82 static int kernel_poll_pipe[2];
83
84 /*
85 * Quit pipe for all threads. This permits a single cancellation point
86 * for all threads when receiving an event on the pipe.
87 */
88 static int thread_quit_pipe[2];
89
90 /* Pthread, Mutexes and Semaphores */
91 static pthread_t kconsumerd_thread;
92 static pthread_t apps_thread;
93 static pthread_t client_thread;
94 static pthread_t kernel_thread;
95 static sem_t kconsumerd_sem;
96
97 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
98
99 static int modprobe_remove_kernel_modules(void);
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 static gid_t allowed_group(void)
114 {
115 struct group *grp;
116
117 if (opt_tracing_group) {
118 grp = getgrnam(opt_tracing_group);
119 } else {
120 grp = getgrnam(default_tracing_group);
121 }
122 if (!grp) {
123 return -1;
124 } else {
125 return grp->gr_gid;
126 }
127 }
128
129 /*
130 * Init quit pipe.
131 *
132 * Return -1 on error or 0 if all pipes are created.
133 */
134 static int init_thread_quit_pipe(void)
135 {
136 int ret;
137
138 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
139 if (ret < 0) {
140 perror("thread quit pipe");
141 goto error;
142 }
143
144 error:
145 return ret;
146 }
147
148 /*
149 * Complete teardown of a kernel session. This free all data structure related
150 * to a kernel session and update counter.
151 */
152 static void teardown_kernel_session(struct ltt_session *session)
153 {
154 if (session->kernel_session != NULL) {
155 DBG("Tearing down kernel session");
156
157 /*
158 * If a custom kernel consumer was registered, close the socket before
159 * tearing down the complete kernel session structure
160 */
161 if (session->kernel_session->consumer_fd != kconsumerd_cmd_sock) {
162 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
163 }
164
165 trace_destroy_kernel_session(session->kernel_session);
166 /* Extra precaution */
167 session->kernel_session = NULL;
168 }
169 }
170
171 static void stop_threads(void)
172 {
173 /* Stopping all threads */
174 DBG("Terminating all threads");
175 close(thread_quit_pipe[0]);
176 close(thread_quit_pipe[1]);
177 }
178
179 /*
180 * Cleanup the daemon
181 */
182 static void cleanup(void)
183 {
184 int ret;
185 char *cmd;
186 struct ltt_session *sess, *stmp;
187
188 DBG("Cleaning up");
189
190 /* <fun> */
191 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
192 "Matthew, BEET driven development works!%c[%dm",
193 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
194 /* </fun> */
195
196 DBG("Removing %s directory", LTTNG_RUNDIR);
197 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
198 if (ret < 0) {
199 ERR("asprintf failed. Something is really wrong!");
200 }
201
202 /* Remove lttng run directory */
203 ret = system(cmd);
204 if (ret < 0) {
205 ERR("Unable to clean " LTTNG_RUNDIR);
206 }
207
208 DBG("Cleaning up all session");
209
210 /* Destroy session list mutex */
211 if (session_list_ptr != NULL) {
212 pthread_mutex_destroy(&session_list_ptr->lock);
213
214 /* Cleanup ALL session */
215 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
216 teardown_kernel_session(sess);
217 // TODO complete session cleanup (including UST)
218 }
219 }
220
221 pthread_mutex_destroy(&kconsumerd_pid_mutex);
222
223 DBG("Closing kernel fd");
224 close(kernel_tracer_fd);
225
226 DBG("Unloading kernel modules");
227 modprobe_remove_kernel_modules();
228 }
229
230 /*
231 * Send data on a unix socket using the liblttsessiondcomm API.
232 *
233 * Return lttcomm error code.
234 */
235 static int send_unix_sock(int sock, void *buf, size_t len)
236 {
237 /* Check valid length */
238 if (len <= 0) {
239 return -1;
240 }
241
242 return lttcomm_send_unix_sock(sock, buf, len);
243 }
244
245 /*
246 * Free memory of a command context structure.
247 */
248 static void clean_command_ctx(struct command_ctx **cmd_ctx)
249 {
250 DBG("Clean command context structure");
251 if (*cmd_ctx) {
252 if ((*cmd_ctx)->llm) {
253 free((*cmd_ctx)->llm);
254 }
255 if ((*cmd_ctx)->lsm) {
256 free((*cmd_ctx)->lsm);
257 }
258 free(*cmd_ctx);
259 *cmd_ctx = NULL;
260 }
261 }
262
263 /*
264 * Send all stream fds of kernel channel to the consumer.
265 */
266 static int send_kconsumerd_channel_fds(int sock, struct ltt_kernel_channel *channel)
267 {
268 int ret;
269 size_t nb_fd;
270 struct ltt_kernel_stream *stream;
271 struct lttcomm_kconsumerd_header lkh;
272 struct lttcomm_kconsumerd_msg lkm;
273
274 DBG("Sending fds of channel %s to kernel consumer", channel->channel->name);
275
276 nb_fd = channel->stream_count;
277
278 /* Setup header */
279 lkh.payload_size = nb_fd * sizeof(struct lttcomm_kconsumerd_msg);
280 lkh.cmd_type = ADD_STREAM;
281
282 DBG("Sending kconsumerd header");
283
284 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
285 if (ret < 0) {
286 perror("send kconsumerd header");
287 goto error;
288 }
289
290 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
291 if (stream->fd != 0) {
292 lkm.fd = stream->fd;
293 lkm.state = stream->state;
294 lkm.max_sb_size = channel->channel->attr.subbuf_size;
295 lkm.output = channel->channel->attr.output;
296 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
297 lkm.path_name[PATH_MAX - 1] = '\0';
298
299 DBG("Sending fd %d to kconsumerd", lkm.fd);
300
301 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
302 if (ret < 0) {
303 perror("send kconsumerd fd");
304 goto error;
305 }
306 }
307 }
308
309 DBG("Kconsumerd channel fds sent");
310
311 return 0;
312
313 error:
314 return ret;
315 }
316
317 /*
318 * Send all stream fds of the kernel session to the consumer.
319 */
320 static int send_kconsumerd_fds(struct ltt_kernel_session *session)
321 {
322 int ret;
323 struct ltt_kernel_channel *chan;
324 struct lttcomm_kconsumerd_header lkh;
325 struct lttcomm_kconsumerd_msg lkm;
326
327 /* Setup header */
328 lkh.payload_size = sizeof(struct lttcomm_kconsumerd_msg);
329 lkh.cmd_type = ADD_STREAM;
330
331 DBG("Sending kconsumerd header for metadata");
332
333 ret = lttcomm_send_unix_sock(session->consumer_fd, &lkh, sizeof(struct lttcomm_kconsumerd_header));
334 if (ret < 0) {
335 perror("send kconsumerd header");
336 goto error;
337 }
338
339 DBG("Sending metadata stream fd");
340
341 /* Extra protection. It's NOT suppose to be set to 0 at this point */
342 if (session->consumer_fd == 0) {
343 session->consumer_fd = kconsumerd_cmd_sock;
344 }
345
346 if (session->metadata_stream_fd != 0) {
347 /* Send metadata stream fd first */
348 lkm.fd = session->metadata_stream_fd;
349 lkm.state = ACTIVE_FD;
350 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
351 lkm.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
352 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
353 lkm.path_name[PATH_MAX - 1] = '\0';
354
355 ret = lttcomm_send_fds_unix_sock(session->consumer_fd, &lkm, &lkm.fd, 1, sizeof(lkm));
356 if (ret < 0) {
357 perror("send kconsumerd fd");
358 goto error;
359 }
360 }
361
362 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
363 ret = send_kconsumerd_channel_fds(session->consumer_fd, chan);
364 if (ret < 0) {
365 goto error;
366 }
367 }
368
369 DBG("Kconsumerd fds (metadata and channel streams) sent");
370
371 return 0;
372
373 error:
374 return ret;
375 }
376
377 #ifdef DISABLED
378 /*
379 * Return a socket connected to the libust communication socket of the
380 * application identified by the pid.
381 *
382 * If the pid is not found in the traceable list, return -1 to indicate error.
383 */
384 static int ust_connect_app(pid_t pid)
385 {
386 int sock;
387 struct ltt_traceable_app *lta;
388
389 DBG("Connect to application pid %d", pid);
390
391 lta = find_app_by_pid(pid);
392 if (lta == NULL) {
393 /* App not found */
394 DBG("Application pid %d not found", pid);
395 return -1;
396 }
397
398 sock = ustctl_connect_pid(lta->pid);
399 if (sock < 0) {
400 ERR("Fail connecting to the PID %d", pid);
401 }
402
403 return sock;
404 }
405 #endif /* DISABLED */
406
407 /*
408 * Notify apps by writing 42 to a named pipe using name. Every applications
409 * waiting for a ltt-sessiond will be notified and re-register automatically to
410 * the session daemon.
411 *
412 * Return open or write error value.
413 */
414 static int notify_apps(const char *name)
415 {
416 int fd;
417 int ret = -1;
418
419 DBG("Notify the global application pipe");
420
421 /* Try opening the global pipe */
422 fd = open(name, O_WRONLY);
423 if (fd < 0) {
424 goto error;
425 }
426
427 /* Notify by writing on the pipe */
428 ret = write(fd, "42", 2);
429 if (ret < 0) {
430 perror("write");
431 }
432
433 error:
434 return ret;
435 }
436
437 /*
438 * Setup the outgoing data buffer for the response (llm) by allocating the
439 * right amount of memory and copying the original information from the lsm
440 * structure.
441 *
442 * Return total size of the buffer pointed by buf.
443 */
444 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
445 {
446 int ret, buf_size;
447
448 buf_size = size;
449
450 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
451 if (cmd_ctx->llm == NULL) {
452 perror("malloc");
453 ret = -ENOMEM;
454 goto error;
455 }
456
457 /* Copy common data */
458 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
459 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
460
461 cmd_ctx->llm->data_size = size;
462 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
463
464 return buf_size;
465
466 error:
467 return ret;
468 }
469
470 /*
471 * Update the kernel pollfd set of all channel fd available over all tracing
472 * session. Add the wakeup pipe at the end of the set.
473 */
474 static int update_kernel_pollfd(void)
475 {
476 int i = 0;
477 /*
478 * The wakup pipe and the quit pipe are needed so the number of fds starts
479 * at 2 for those pipes.
480 */
481 unsigned int nb_fd = 2;
482 struct ltt_session *session;
483 struct ltt_kernel_channel *channel;
484
485 DBG("Updating kernel_pollfd");
486
487 /* Get the number of channel of all kernel session */
488 lock_session_list();
489 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
490 lock_session(session);
491 if (session->kernel_session == NULL) {
492 unlock_session(session);
493 continue;
494 }
495 nb_fd += session->kernel_session->channel_count;
496 unlock_session(session);
497 }
498
499 DBG("Resizing kernel_pollfd to size %d", nb_fd);
500
501 kernel_pollfd = realloc(kernel_pollfd, nb_fd * sizeof(struct pollfd));
502 if (kernel_pollfd == NULL) {
503 perror("malloc kernel_pollfd");
504 goto error;
505 }
506
507 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
508 lock_session(session);
509 if (session->kernel_session == NULL) {
510 unlock_session(session);
511 continue;
512 }
513 if (i >= nb_fd) {
514 ERR("To much channel for kernel_pollfd size");
515 unlock_session(session);
516 break;
517 }
518 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
519 kernel_pollfd[i].fd = channel->fd;
520 kernel_pollfd[i].events = POLLIN | POLLRDNORM;
521 i++;
522 }
523 unlock_session(session);
524 }
525 unlock_session_list();
526
527 /* Adding wake up pipe */
528 kernel_pollfd[nb_fd - 2].fd = kernel_poll_pipe[0];
529 kernel_pollfd[nb_fd - 2].events = POLLIN;
530
531 /* Adding the quit pipe */
532 kernel_pollfd[nb_fd - 1].fd = thread_quit_pipe[0];
533
534 return nb_fd;
535
536 error:
537 unlock_session_list();
538 return -1;
539 }
540
541 /*
542 * Find the channel fd from 'fd' over all tracing session. When found, check
543 * for new channel stream and send those stream fds to the kernel consumer.
544 *
545 * Useful for CPU hotplug feature.
546 */
547 static int update_kernel_stream(int fd)
548 {
549 int ret = 0;
550 struct ltt_session *session;
551 struct ltt_kernel_channel *channel;
552
553 DBG("Updating kernel streams for channel fd %d", fd);
554
555 lock_session_list();
556 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
557 lock_session(session);
558 if (session->kernel_session == NULL) {
559 unlock_session(session);
560 continue;
561 }
562
563 /* This is not suppose to be 0 but this is an extra security check */
564 if (session->kernel_session->consumer_fd == 0) {
565 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
566 }
567
568 cds_list_for_each_entry(channel, &session->kernel_session->channel_list.head, list) {
569 if (channel->fd == fd) {
570 DBG("Channel found, updating kernel streams");
571 ret = kernel_open_channel_stream(channel);
572 if (ret < 0) {
573 goto end;
574 }
575
576 /*
577 * Have we already sent fds to the consumer? If yes, it means that
578 * tracing is started so it is safe to send our updated stream fds.
579 */
580 if (session->kernel_session->kconsumer_fds_sent == 1) {
581 ret = send_kconsumerd_channel_fds(session->kernel_session->consumer_fd,
582 channel);
583 if (ret < 0) {
584 goto end;
585 }
586 }
587 goto end;
588 }
589 }
590 unlock_session(session);
591 }
592
593 end:
594 unlock_session_list();
595 if (session) {
596 unlock_session(session);
597 }
598 return ret;
599 }
600
601 /*
602 * This thread manage event coming from the kernel.
603 *
604 * Features supported in this thread:
605 * -) CPU Hotplug
606 */
607 static void *thread_manage_kernel(void *data)
608 {
609 int ret, i, nb_fd = 0;
610 char tmp;
611 int update_poll_flag = 1;
612
613 DBG("Thread manage kernel started");
614
615 while (1) {
616 if (update_poll_flag == 1) {
617 nb_fd = update_kernel_pollfd();
618 if (nb_fd < 0) {
619 goto error;
620 }
621 update_poll_flag = 0;
622 }
623
624 DBG("Polling on %d fds", nb_fd);
625
626 /* Poll infinite value of time */
627 ret = poll(kernel_pollfd, nb_fd, -1);
628 if (ret < 0) {
629 perror("poll kernel thread");
630 goto error;
631 } else if (ret == 0) {
632 /* Should not happen since timeout is infinite */
633 continue;
634 }
635
636 /* Thread quit pipe has been closed. Killing thread. */
637 if (kernel_pollfd[nb_fd - 1].revents == POLLNVAL) {
638 goto error;
639 }
640
641 DBG("Kernel poll event triggered");
642
643 /*
644 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
645 * must be updated.
646 */
647 switch (kernel_pollfd[nb_fd - 2].revents) {
648 case POLLIN:
649 ret = read(kernel_poll_pipe[0], &tmp, 1);
650 update_poll_flag = 1;
651 continue;
652 case POLLERR:
653 goto error;
654 default:
655 break;
656 }
657
658 for (i = 0; i < nb_fd; i++) {
659 switch (kernel_pollfd[i].revents) {
660 /*
661 * New CPU detected by the kernel. Adding kernel stream to kernel
662 * session and updating the kernel consumer
663 */
664 case POLLIN | POLLRDNORM:
665 ret = update_kernel_stream(kernel_pollfd[i].fd);
666 if (ret < 0) {
667 continue;
668 }
669 break;
670 }
671 }
672 }
673
674 error:
675 DBG("Kernel thread dying");
676 if (kernel_pollfd) {
677 free(kernel_pollfd);
678 }
679
680 close(kernel_poll_pipe[0]);
681 close(kernel_poll_pipe[1]);
682 return NULL;
683 }
684
685 /*
686 * This thread manage the kconsumerd error sent back to the session daemon.
687 */
688 static void *thread_manage_kconsumerd(void *data)
689 {
690 int sock = 0, ret;
691 enum lttcomm_return_code code;
692 struct pollfd pollfd[2];
693
694 DBG("[thread] Manage kconsumerd started");
695
696 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
697 if (ret < 0) {
698 goto error;
699 }
700
701 /* First fd is always the quit pipe */
702 pollfd[0].fd = thread_quit_pipe[0];
703
704 /* Apps socket */
705 pollfd[1].fd = kconsumerd_err_sock;
706 pollfd[1].events = POLLIN;
707
708 /* Inifinite blocking call, waiting for transmission */
709 ret = poll(pollfd, 2, -1);
710 if (ret < 0) {
711 perror("poll kconsumerd thread");
712 goto error;
713 }
714
715 /* Thread quit pipe has been closed. Killing thread. */
716 if (pollfd[0].revents == POLLNVAL) {
717 goto error;
718 } else if (pollfd[1].revents == POLLERR) {
719 ERR("Kconsumerd err socket poll error");
720 goto error;
721 }
722
723 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
724 if (sock < 0) {
725 goto error;
726 }
727
728 /* Getting status code from kconsumerd */
729 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
730 if (ret <= 0) {
731 goto error;
732 }
733
734 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
735 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
736 if (kconsumerd_cmd_sock < 0) {
737 sem_post(&kconsumerd_sem);
738 perror("kconsumerd connect");
739 goto error;
740 }
741 /* Signal condition to tell that the kconsumerd is ready */
742 sem_post(&kconsumerd_sem);
743 DBG("Kconsumerd command socket ready");
744 } else {
745 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
746 lttcomm_get_readable_code(-code));
747 goto error;
748 }
749
750 /* Kconsumerd err socket */
751 pollfd[1].fd = sock;
752 pollfd[1].events = POLLIN;
753
754 /* Inifinite blocking call, waiting for transmission */
755 ret = poll(pollfd, 2, -1);
756 if (ret < 0) {
757 perror("poll kconsumerd thread");
758 goto error;
759 }
760
761 /* Thread quit pipe has been closed. Killing thread. */
762 if (pollfd[0].revents == POLLNVAL) {
763 goto error;
764 } else if (pollfd[1].revents == POLLERR) {
765 ERR("Kconsumerd err socket second poll error");
766 goto error;
767 }
768
769 /* Wait for any kconsumerd error */
770 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
771 if (ret <= 0) {
772 ERR("Kconsumerd closed the command socket");
773 goto error;
774 }
775
776 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
777
778 error:
779 DBG("Kconsumerd thread dying");
780 if (kconsumerd_err_sock) {
781 close(kconsumerd_err_sock);
782 }
783 if (kconsumerd_cmd_sock) {
784 close(kconsumerd_cmd_sock);
785 }
786 if (sock) {
787 close(sock);
788 }
789
790 unlink(kconsumerd_err_unix_sock_path);
791 unlink(kconsumerd_cmd_unix_sock_path);
792
793 kconsumerd_pid = 0;
794 return NULL;
795 }
796
797 /*
798 * This thread manage the application socket communication
799 */
800 static void *thread_manage_apps(void *data)
801 {
802 int sock = 0, ret;
803 struct pollfd pollfd[2];
804
805 /* TODO: Something more elegant is needed but fine for now */
806 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
807 * for 32-bit vs 64-bit compat processes. */
808 /* replicate in ust with version number */
809 struct {
810 int reg; /* 1:register, 0:unregister */
811 pid_t pid;
812 uid_t uid;
813 } reg_msg;
814
815 DBG("[thread] Manage apps started");
816
817 ret = lttcomm_listen_unix_sock(apps_sock);
818 if (ret < 0) {
819 goto error;
820 }
821
822 /* First fd is always the quit pipe */
823 pollfd[0].fd = thread_quit_pipe[0];
824
825 /* Apps socket */
826 pollfd[1].fd = apps_sock;
827 pollfd[1].events = POLLIN;
828
829 /* Notify all applications to register */
830 notify_apps(default_global_apps_pipe);
831
832 while (1) {
833 DBG("Accepting application registration");
834
835 /* Inifinite blocking call, waiting for transmission */
836 ret = poll(pollfd, 2, -1);
837 if (ret < 0) {
838 perror("poll apps thread");
839 goto error;
840 }
841
842 /* Thread quit pipe has been closed. Killing thread. */
843 if (pollfd[0].revents == POLLNVAL) {
844 goto error;
845 } else if (pollfd[1].revents == POLLERR) {
846 ERR("Apps socket poll error");
847 goto error;
848 }
849
850 sock = lttcomm_accept_unix_sock(apps_sock);
851 if (sock < 0) {
852 goto error;
853 }
854
855 /*
856 * Using message-based transmissions to ensure we don't
857 * have to deal with partially received messages.
858 */
859 ret = lttcomm_recv_unix_sock(sock, &reg_msg, sizeof(reg_msg));
860 if (ret < 0) {
861 perror("recv");
862 continue;
863 }
864
865 /* Add application to the global traceable list */
866 if (reg_msg.reg == 1) {
867 /* Registering */
868 /*
869 * TODO: socket should be either passed to a
870 * listener thread (for more messages) or
871 * closed. It currently leaks.
872 */
873 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
874 if (ret < 0) {
875 /* register_traceable_app only return an error with
876 * ENOMEM. At this point, we better stop everything.
877 */
878 goto error;
879 }
880 } else {
881 /* Unregistering */
882 unregister_traceable_app(reg_msg.pid);
883 }
884 }
885
886 error:
887 DBG("Apps thread dying");
888 if (apps_sock) {
889 close(apps_sock);
890 }
891 if (sock) {
892 close(sock);
893 }
894
895 unlink(apps_unix_sock_path);
896 return NULL;
897 }
898
899 /*
900 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
901 * exec or it will fails.
902 */
903 static int spawn_kconsumerd_thread(void)
904 {
905 int ret;
906
907 /* Setup semaphore */
908 sem_init(&kconsumerd_sem, 0, 0);
909
910 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
911 if (ret != 0) {
912 perror("pthread_create kconsumerd");
913 goto error;
914 }
915
916 /* Wait for the kconsumerd thread to be ready */
917 sem_wait(&kconsumerd_sem);
918
919 if (kconsumerd_pid == 0) {
920 ERR("Kconsumerd did not start");
921 goto error;
922 }
923
924 return 0;
925
926 error:
927 ret = LTTCOMM_KERN_CONSUMER_FAIL;
928 return ret;
929 }
930
931 /*
932 * Join kernel consumer thread
933 */
934 static int join_kconsumerd_thread(void)
935 {
936 void *status;
937 int ret;
938
939 if (kconsumerd_pid != 0) {
940 ret = kill(kconsumerd_pid, SIGTERM);
941 if (ret) {
942 ERR("Error killing kconsumerd");
943 return ret;
944 }
945 return pthread_join(kconsumerd_thread, &status);
946 } else {
947 return 0;
948 }
949 }
950
951 /*
952 * Fork and exec a kernel consumer daemon (kconsumerd).
953 *
954 * Return pid if successful else -1.
955 */
956 static pid_t spawn_kconsumerd(void)
957 {
958 int ret;
959 pid_t pid;
960 const char *verbosity;
961
962 DBG("Spawning kconsumerd");
963
964 pid = fork();
965 if (pid == 0) {
966 /*
967 * Exec kconsumerd.
968 */
969 if (opt_verbose > 1 || opt_verbose_kconsumerd) {
970 verbosity = "--verbose";
971 } else {
972 verbosity = "--quiet";
973 }
974 execl(INSTALL_BIN_PATH "/ltt-kconsumerd", "ltt-kconsumerd", verbosity, NULL);
975 if (errno != 0) {
976 perror("kernel start consumer exec");
977 }
978 exit(EXIT_FAILURE);
979 } else if (pid > 0) {
980 ret = pid;
981 goto error;
982 } else {
983 perror("kernel start consumer fork");
984 ret = -errno;
985 goto error;
986 }
987
988 error:
989 return ret;
990 }
991
992 /*
993 * Spawn the kconsumerd daemon and session daemon thread.
994 */
995 static int start_kconsumerd(void)
996 {
997 int ret;
998
999 pthread_mutex_lock(&kconsumerd_pid_mutex);
1000 if (kconsumerd_pid != 0) {
1001 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1002 goto end;
1003 }
1004
1005 ret = spawn_kconsumerd();
1006 if (ret < 0) {
1007 ERR("Spawning kconsumerd failed");
1008 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1009 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1010 goto error;
1011 }
1012
1013 /* Setting up the global kconsumerd_pid */
1014 kconsumerd_pid = ret;
1015 pthread_mutex_unlock(&kconsumerd_pid_mutex);
1016
1017 DBG("Kconsumerd pid %d", ret);
1018
1019 DBG("Spawning kconsumerd thread");
1020 ret = spawn_kconsumerd_thread();
1021 if (ret < 0) {
1022 ERR("Fatal error spawning kconsumerd thread");
1023 goto error;
1024 }
1025
1026 end:
1027 return 0;
1028
1029 error:
1030 return ret;
1031 }
1032
1033 /*
1034 * modprobe_kernel_modules
1035 */
1036 static int modprobe_kernel_modules(void)
1037 {
1038 int ret = 0, i;
1039 char modprobe[256];
1040
1041 for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
1042 ret = snprintf(modprobe, sizeof(modprobe),
1043 "/sbin/modprobe %s%s",
1044 kernel_modules_list[i].required ? "" : "--quiet ",
1045 kernel_modules_list[i].name);
1046 if (ret < 0) {
1047 perror("snprintf modprobe");
1048 goto error;
1049 }
1050 modprobe[sizeof(modprobe) - 1] = '\0';
1051 ret = system(modprobe);
1052 if (ret == -1) {
1053 ERR("Unable to launch modprobe for module %s",
1054 kernel_modules_list[i].name);
1055 } else if (kernel_modules_list[i].required
1056 && WEXITSTATUS(ret) != 0) {
1057 ERR("Unable to load module %s",
1058 kernel_modules_list[i].name);
1059 } else {
1060 DBG("Modprobe successfully %s",
1061 kernel_modules_list[i].name);
1062 }
1063 }
1064
1065 error:
1066 return ret;
1067 }
1068
1069 /*
1070 * modprobe_remove_kernel_modules
1071 * Remove modules in reverse load order.
1072 */
1073 static int modprobe_remove_kernel_modules(void)
1074 {
1075 int ret = 0, i;
1076 char modprobe[256];
1077
1078 for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
1079 ret = snprintf(modprobe, sizeof(modprobe),
1080 "/sbin/modprobe --remove --quiet %s",
1081 kernel_modules_list[i].name);
1082 if (ret < 0) {
1083 perror("snprintf modprobe --remove");
1084 goto error;
1085 }
1086 modprobe[sizeof(modprobe) - 1] = '\0';
1087 ret = system(modprobe);
1088 if (ret == -1) {
1089 ERR("Unable to launch modprobe --remove for module %s",
1090 kernel_modules_list[i].name);
1091 } else if (kernel_modules_list[i].required
1092 && WEXITSTATUS(ret) != 0) {
1093 ERR("Unable to remove module %s",
1094 kernel_modules_list[i].name);
1095 } else {
1096 DBG("Modprobe removal successful %s",
1097 kernel_modules_list[i].name);
1098 }
1099 }
1100
1101 error:
1102 return ret;
1103 }
1104
1105 /*
1106 * mount_debugfs
1107 */
1108 static int mount_debugfs(char *path)
1109 {
1110 int ret;
1111 char *type = "debugfs";
1112
1113 ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
1114 if (ret < 0) {
1115 goto error;
1116 }
1117
1118 ret = mount(type, path, type, 0, NULL);
1119 if (ret < 0) {
1120 perror("mount debugfs");
1121 goto error;
1122 }
1123
1124 DBG("Mounted debugfs successfully at %s", path);
1125
1126 error:
1127 return ret;
1128 }
1129
1130 /*
1131 * Setup necessary data for kernel tracer action.
1132 */
1133 static void init_kernel_tracer(void)
1134 {
1135 int ret;
1136 char *proc_mounts = "/proc/mounts";
1137 char line[256];
1138 char *debugfs_path = NULL, *lttng_path;
1139 FILE *fp;
1140
1141 /* Detect debugfs */
1142 fp = fopen(proc_mounts, "r");
1143 if (fp == NULL) {
1144 ERR("Unable to probe %s", proc_mounts);
1145 goto error;
1146 }
1147
1148 while (fgets(line, sizeof(line), fp) != NULL) {
1149 if (strstr(line, "debugfs") != NULL) {
1150 /* Remove first string */
1151 strtok(line, " ");
1152 /* Dup string here so we can reuse line later on */
1153 debugfs_path = strdup(strtok(NULL, " "));
1154 DBG("Got debugfs path : %s", debugfs_path);
1155 break;
1156 }
1157 }
1158
1159 fclose(fp);
1160
1161 /* Mount debugfs if needded */
1162 if (debugfs_path == NULL) {
1163 ret = asprintf(&debugfs_path, "/mnt/debugfs");
1164 if (ret < 0) {
1165 perror("asprintf debugfs path");
1166 goto error;
1167 }
1168 ret = mount_debugfs(debugfs_path);
1169 if (ret < 0) {
1170 goto error;
1171 }
1172 }
1173
1174 /* Modprobe lttng kernel modules */
1175 ret = modprobe_kernel_modules();
1176 if (ret < 0) {
1177 goto error;
1178 }
1179
1180 /* Setup lttng kernel path */
1181 ret = asprintf(&lttng_path, "%s/lttng", debugfs_path);
1182 if (ret < 0) {
1183 perror("asprintf lttng path");
1184 goto error;
1185 }
1186
1187 /* Open debugfs lttng */
1188 kernel_tracer_fd = open(lttng_path, O_RDWR);
1189 if (kernel_tracer_fd < 0) {
1190 DBG("Failed to open %s", lttng_path);
1191 goto error;
1192 }
1193
1194 free(lttng_path);
1195 free(debugfs_path);
1196 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1197 return;
1198
1199 error:
1200 if (lttng_path) {
1201 free(lttng_path);
1202 }
1203 if (debugfs_path) {
1204 free(debugfs_path);
1205 }
1206 WARN("No kernel tracer available");
1207 kernel_tracer_fd = 0;
1208 return;
1209 }
1210
1211 /*
1212 * Start tracing by creating trace directory and sending FDs to the kernel
1213 * consumer.
1214 */
1215 static int start_kernel_trace(struct ltt_kernel_session *session)
1216 {
1217 int ret = 0;
1218
1219 if (session->kconsumer_fds_sent == 0) {
1220 /*
1221 * Assign default kernel consumer if no consumer assigned to the kernel
1222 * session. At this point, it's NOT suppose to be 0 but this is an extra
1223 * security check.
1224 */
1225 if (session->consumer_fd == 0) {
1226 session->consumer_fd = kconsumerd_cmd_sock;
1227 }
1228
1229 ret = send_kconsumerd_fds(session);
1230 if (ret < 0) {
1231 ERR("Send kconsumerd fds failed");
1232 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1233 goto error;
1234 }
1235
1236 session->kconsumer_fds_sent = 1;
1237 }
1238
1239 error:
1240 return ret;
1241 }
1242
1243 /*
1244 * Notify kernel thread to update it's pollfd.
1245 */
1246 static int notify_kernel_pollfd(void)
1247 {
1248 int ret;
1249
1250 /* Inform kernel thread of the new kernel channel */
1251 ret = write(kernel_poll_pipe[1], "!", 1);
1252 if (ret < 0) {
1253 perror("write kernel poll pipe");
1254 }
1255
1256 return ret;
1257 }
1258
1259 /*
1260 * Allocate a channel structure and fill it.
1261 */
1262 static struct lttng_channel *init_default_channel(enum lttng_domain_type domain_type,
1263 char *name)
1264 {
1265 struct lttng_channel *chan;
1266
1267 chan = malloc(sizeof(struct lttng_channel));
1268 if (chan == NULL) {
1269 perror("init channel malloc");
1270 goto error;
1271 }
1272
1273 if (snprintf(chan->name, NAME_MAX, "%s", name) < 0) {
1274 perror("snprintf channel name");
1275 goto error;
1276 }
1277
1278 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
1279 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1280 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1281
1282 switch (domain_type) {
1283 case LTTNG_DOMAIN_KERNEL:
1284 chan->attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
1285 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1286 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1287 break;
1288 /* TODO: add UST */
1289 default:
1290 goto error; /* Not implemented */
1291 }
1292
1293 return chan;
1294
1295 error:
1296 free(chan);
1297 return NULL;
1298 }
1299
1300 /*
1301 * Create a kernel tracer session then create the default channel.
1302 */
1303 static int create_kernel_session(struct ltt_session *session)
1304 {
1305 int ret;
1306
1307 DBG("Creating kernel session");
1308
1309 ret = kernel_create_session(session, kernel_tracer_fd);
1310 if (ret < 0) {
1311 ret = LTTCOMM_KERN_SESS_FAIL;
1312 goto error;
1313 }
1314
1315 /* Set kernel consumer socket fd */
1316 if (kconsumerd_cmd_sock) {
1317 session->kernel_session->consumer_fd = kconsumerd_cmd_sock;
1318 }
1319
1320 ret = asprintf(&session->kernel_session->trace_path, "%s/kernel",
1321 session->path);
1322 if (ret < 0) {
1323 perror("asprintf kernel traces path");
1324 goto error;
1325 }
1326
1327 ret = mkdir_recursive(session->kernel_session->trace_path,
1328 S_IRWXU | S_IRWXG, geteuid(), allowed_group());
1329 if (ret < 0) {
1330 if (ret != -EEXIST) {
1331 ERR("Trace directory creation error");
1332 goto error;
1333 }
1334 }
1335
1336 error:
1337 return ret;
1338 }
1339
1340 /*
1341 * Using the session list, filled a lttng_session array to send back to the
1342 * client for session listing.
1343 *
1344 * The session list lock MUST be acquired before calling this function. Use
1345 * lock_session_list() and unlock_session_list().
1346 */
1347 static void list_lttng_sessions(struct lttng_session *sessions)
1348 {
1349 int i = 0;
1350 struct ltt_session *session;
1351
1352 DBG("Getting all available session");
1353 /*
1354 * Iterate over session list and append data after the control struct in
1355 * the buffer.
1356 */
1357 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1358 strncpy(sessions[i].path, session->path, PATH_MAX);
1359 sessions[i].path[PATH_MAX - 1] = '\0';
1360 strncpy(sessions[i].name, session->name, NAME_MAX);
1361 sessions[i].name[NAME_MAX - 1] = '\0';
1362 i++;
1363 }
1364 }
1365
1366 /*
1367 * Fill lttng_channel array of all channels.
1368 */
1369 static void list_lttng_channels(struct ltt_session *session,
1370 struct lttng_channel *channels)
1371 {
1372 int i = 0;
1373 struct ltt_kernel_channel *kchan;
1374
1375 DBG("Listing channels for session %s", session->name);
1376
1377 /* Kernel channels */
1378 if (session->kernel_session != NULL) {
1379 cds_list_for_each_entry(kchan, &session->kernel_session->channel_list.head, list) {
1380 /* Copy lttng_channel struct to array */
1381 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1382 channels[i].enabled = kchan->enabled;
1383 i++;
1384 }
1385 }
1386
1387 /* TODO: Missing UST listing */
1388 }
1389
1390 /*
1391 * Fill lttng_event array of all events in the channel.
1392 */
1393 static void list_lttng_events(struct ltt_kernel_channel *kchan,
1394 struct lttng_event *events)
1395 {
1396 /*
1397 * TODO: This is ONLY kernel. Need UST support.
1398 */
1399 int i = 0;
1400 struct ltt_kernel_event *event;
1401
1402 DBG("Listing events for channel %s", kchan->channel->name);
1403
1404 /* Kernel channels */
1405 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
1406 strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
1407 events[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1408 events[i].enabled = event->enabled;
1409 switch (event->event->instrumentation) {
1410 case LTTNG_KERNEL_TRACEPOINT:
1411 events[i].type = LTTNG_EVENT_TRACEPOINT;
1412 break;
1413 case LTTNG_KERNEL_KPROBE:
1414 case LTTNG_KERNEL_KRETPROBE:
1415 events[i].type = LTTNG_EVENT_PROBE;
1416 memcpy(&events[i].attr.probe, &event->event->u.kprobe,
1417 sizeof(struct lttng_kernel_kprobe));
1418 break;
1419 case LTTNG_KERNEL_FUNCTION:
1420 events[i].type = LTTNG_EVENT_FUNCTION;
1421 memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
1422 sizeof(struct lttng_kernel_function));
1423 break;
1424 }
1425 i++;
1426 }
1427 }
1428
1429 /*
1430 * Process the command requested by the lttng client within the command
1431 * context structure. This function make sure that the return structure (llm)
1432 * is set and ready for transmission before returning.
1433 *
1434 * Return any error encountered or 0 for success.
1435 */
1436 static int process_client_msg(struct command_ctx *cmd_ctx)
1437 {
1438 int ret = LTTCOMM_OK;
1439
1440 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
1441
1442 /*
1443 * Commands that DO NOT need a session.
1444 */
1445 switch (cmd_ctx->lsm->cmd_type) {
1446 case LTTNG_CREATE_SESSION:
1447 case LTTNG_LIST_SESSIONS:
1448 case LTTNG_LIST_TRACEPOINTS:
1449 case LTTNG_CALIBRATE:
1450 break;
1451 default:
1452 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
1453 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session.name);
1454 if (cmd_ctx->session == NULL) {
1455 /* If session name not found */
1456 if (cmd_ctx->lsm->session.name != NULL) {
1457 ret = LTTCOMM_SESS_NOT_FOUND;
1458 } else { /* If no session name specified */
1459 ret = LTTCOMM_SELECT_SESS;
1460 }
1461 goto error;
1462 } else {
1463 /* Acquire lock for the session */
1464 lock_session(cmd_ctx->session);
1465 }
1466 break;
1467 }
1468
1469 /*
1470 * Check domain type for specific "pre-action".
1471 */
1472 switch (cmd_ctx->lsm->domain.type) {
1473 case LTTNG_DOMAIN_KERNEL:
1474 /* Kernel tracer check */
1475 if (kernel_tracer_fd == 0) {
1476 init_kernel_tracer();
1477 if (kernel_tracer_fd == 0) {
1478 ret = LTTCOMM_KERN_NA;
1479 goto error;
1480 }
1481 }
1482
1483 /* Need a session for kernel command */
1484 switch (cmd_ctx->lsm->cmd_type) {
1485 case LTTNG_CALIBRATE:
1486 case LTTNG_CREATE_SESSION:
1487 case LTTNG_LIST_SESSIONS:
1488 case LTTNG_LIST_TRACEPOINTS:
1489 break;
1490 default:
1491 if (cmd_ctx->session->kernel_session == NULL) {
1492 ret = create_kernel_session(cmd_ctx->session);
1493 if (ret < 0) {
1494 ret = LTTCOMM_KERN_SESS_FAIL;
1495 goto error;
1496 }
1497
1498 /* Start the kernel consumer daemon */
1499
1500 if (kconsumerd_pid == 0 &&
1501 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
1502 ret = start_kconsumerd();
1503 if (ret < 0) {
1504 goto error;
1505 }
1506 }
1507 }
1508 }
1509 break;
1510 default:
1511 break;
1512 }
1513
1514 /* Process by command type */
1515 switch (cmd_ctx->lsm->cmd_type) {
1516 case LTTNG_ADD_CONTEXT:
1517 {
1518 struct lttng_kernel_context kctx;
1519
1520 /* Setup lttng message with no payload */
1521 ret = setup_lttng_msg(cmd_ctx, 0);
1522 if (ret < 0) {
1523 goto setup_error;
1524 }
1525
1526 switch (cmd_ctx->lsm->domain.type) {
1527 case LTTNG_DOMAIN_KERNEL:
1528 /* Create Kernel context */
1529 kctx.ctx = cmd_ctx->lsm->u.context.ctx.ctx;
1530 kctx.u.perf_counter.type = cmd_ctx->lsm->u.context.ctx.u.perf_counter.type;
1531 kctx.u.perf_counter.config = cmd_ctx->lsm->u.context.ctx.u.perf_counter.config;
1532 strncpy(kctx.u.perf_counter.name,
1533 cmd_ctx->lsm->u.context.ctx.u.perf_counter.name,
1534 LTTNG_SYMBOL_NAME_LEN);
1535 kctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1536
1537 /* Add kernel context to kernel tracer. See context.c */
1538 ret = add_kernel_context(cmd_ctx->session->kernel_session, &kctx,
1539 cmd_ctx->lsm->u.context.event_name,
1540 cmd_ctx->lsm->u.context.channel_name);
1541 if (ret != LTTCOMM_OK) {
1542 goto error;
1543 }
1544 break;
1545 default:
1546 /* TODO: Userspace tracing */
1547 ret = LTTCOMM_NOT_IMPLEMENTED;
1548 goto error;
1549 }
1550
1551 ret = LTTCOMM_OK;
1552 break;
1553 }
1554 case LTTNG_DISABLE_CHANNEL:
1555 {
1556 struct ltt_kernel_channel *kchan;
1557
1558 /* Setup lttng message with no payload */
1559 ret = setup_lttng_msg(cmd_ctx, 0);
1560 if (ret < 0) {
1561 goto setup_error;
1562 }
1563
1564 switch (cmd_ctx->lsm->domain.type) {
1565 case LTTNG_DOMAIN_KERNEL:
1566 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1567 cmd_ctx->session->kernel_session);
1568 if (kchan == NULL) {
1569 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1570 goto error;
1571 } else if (kchan->enabled == 1) {
1572 ret = kernel_disable_channel(kchan);
1573 if (ret < 0) {
1574 if (ret != EEXIST) {
1575 ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL;
1576 }
1577 goto error;
1578 }
1579 }
1580 kernel_wait_quiescent(kernel_tracer_fd);
1581 break;
1582 default:
1583 /* TODO: Userspace tracing */
1584 ret = LTTCOMM_NOT_IMPLEMENTED;
1585 goto error;
1586 }
1587
1588 ret = LTTCOMM_OK;
1589 break;
1590 }
1591 case LTTNG_DISABLE_EVENT:
1592 {
1593 struct ltt_kernel_channel *kchan;
1594 struct ltt_kernel_event *kevent;
1595
1596 /* Setup lttng message with no payload */
1597 ret = setup_lttng_msg(cmd_ctx, 0);
1598 if (ret < 0) {
1599 goto setup_error;
1600 }
1601
1602 switch (cmd_ctx->lsm->domain.type) {
1603 case LTTNG_DOMAIN_KERNEL:
1604 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1605 cmd_ctx->session->kernel_session);
1606 if (kchan == NULL) {
1607 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1608 goto error;
1609 }
1610
1611 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, kchan);
1612 if (kevent != NULL) {
1613 DBG("Disabling kernel event %s for channel %s.", kevent->event->name,
1614 kchan->channel->name);
1615 ret = kernel_disable_event(kevent);
1616 if (ret < 0) {
1617 ret = LTTCOMM_KERN_ENABLE_FAIL;
1618 goto error;
1619 }
1620 }
1621
1622 kernel_wait_quiescent(kernel_tracer_fd);
1623 break;
1624 default:
1625 /* TODO: Userspace tracing */
1626 ret = LTTCOMM_NOT_IMPLEMENTED;
1627 goto error;
1628 }
1629
1630 ret = LTTCOMM_OK;
1631 break;
1632 }
1633 case LTTNG_DISABLE_ALL_EVENT:
1634 {
1635 struct ltt_kernel_channel *kchan;
1636 struct ltt_kernel_event *kevent;
1637
1638 /* Setup lttng message with no payload */
1639 ret = setup_lttng_msg(cmd_ctx, 0);
1640 if (ret < 0) {
1641 goto setup_error;
1642 }
1643
1644 switch (cmd_ctx->lsm->domain.type) {
1645 case LTTNG_DOMAIN_KERNEL:
1646 DBG("Disabling all enabled kernel events");
1647 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
1648 cmd_ctx->session->kernel_session);
1649 if (kchan == NULL) {
1650 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
1651 goto error;
1652 }
1653
1654 /* For each event in the kernel session */
1655 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1656 DBG("Disabling kernel event %s for channel %s.",
1657 kevent->event->name, kchan->channel->name);
1658 ret = kernel_disable_event(kevent);
1659 if (ret < 0) {
1660 continue;
1661 }
1662 }
1663
1664 /* Quiescent wait after event disable */
1665 kernel_wait_quiescent(kernel_tracer_fd);
1666 break;
1667 default:
1668 /* TODO: Userspace tracing */
1669 ret = LTTCOMM_NOT_IMPLEMENTED;
1670 goto error;
1671 }
1672
1673 ret = LTTCOMM_OK;
1674 break;
1675 }
1676 case LTTNG_ENABLE_CHANNEL:
1677 {
1678 struct ltt_kernel_channel *kchan;
1679
1680 /* Setup lttng message with no payload */
1681 ret = setup_lttng_msg(cmd_ctx, 0);
1682 if (ret < 0) {
1683 goto setup_error;
1684 }
1685
1686 switch (cmd_ctx->lsm->domain.type) {
1687 case LTTNG_DOMAIN_KERNEL:
1688 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
1689 cmd_ctx->session->kernel_session);
1690 if (kchan == NULL) {
1691 /* Channel not found, creating it */
1692 DBG("Creating kernel channel");
1693
1694 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1695 &cmd_ctx->lsm->u.channel.chan,
1696 cmd_ctx->session->kernel_session->trace_path);
1697 if (ret < 0) {
1698 ret = LTTCOMM_KERN_CHAN_FAIL;
1699 goto error;
1700 }
1701
1702 /* Notify kernel thread that there is a new channel */
1703 ret = notify_kernel_pollfd();
1704 if (ret < 0) {
1705 ret = LTTCOMM_FATAL;
1706 goto error;
1707 }
1708 } else if (kchan->enabled == 0) {
1709 ret = kernel_enable_channel(kchan);
1710 if (ret < 0) {
1711 if (ret != EEXIST) {
1712 ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL;
1713 }
1714 goto error;
1715 }
1716 }
1717
1718 kernel_wait_quiescent(kernel_tracer_fd);
1719 break;
1720 default:
1721 /* TODO: Userspace tracing */
1722 ret = LTTCOMM_NOT_IMPLEMENTED;
1723 goto error;
1724 }
1725
1726 ret = LTTCOMM_OK;
1727 break;
1728 }
1729 case LTTNG_ENABLE_EVENT:
1730 {
1731 char *channel_name;
1732 struct ltt_kernel_channel *kchan;
1733 struct ltt_kernel_event *kevent;
1734 struct lttng_channel *chan;
1735
1736 /* Setup lttng message with no payload */
1737 ret = setup_lttng_msg(cmd_ctx, 0);
1738 if (ret < 0) {
1739 goto setup_error;
1740 }
1741
1742 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1743
1744 switch (cmd_ctx->lsm->domain.type) {
1745 case LTTNG_DOMAIN_KERNEL:
1746 kchan = get_kernel_channel_by_name(channel_name,
1747 cmd_ctx->session->kernel_session);
1748 if (kchan == NULL) {
1749 DBG("Channel not found. Creating channel %s", channel_name);
1750
1751 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
1752 if (chan == NULL) {
1753 ret = LTTCOMM_FATAL;
1754 goto error;
1755 }
1756
1757 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1758 chan, cmd_ctx->session->kernel_session->trace_path);
1759 if (ret < 0) {
1760 ret = LTTCOMM_KERN_CHAN_FAIL;
1761 goto error;
1762 }
1763 kchan = get_kernel_channel_by_name(channel_name,
1764 cmd_ctx->session->kernel_session);
1765 if (kchan == NULL) {
1766 ERR("Channel %s not found after creation. Internal error, giving up.",
1767 channel_name);
1768 ret = LTTCOMM_FATAL;
1769 goto error;
1770 }
1771 }
1772
1773 kevent = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, kchan);
1774 if (kevent == NULL) {
1775 DBG("Creating kernel event %s for channel %s.",
1776 cmd_ctx->lsm->u.enable.event.name, channel_name);
1777 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, kchan);
1778 } else {
1779 DBG("Enabling kernel event %s for channel %s.",
1780 kevent->event->name, channel_name);
1781 ret = kernel_enable_event(kevent);
1782 if (ret == -EEXIST) {
1783 ret = LTTCOMM_KERN_EVENT_EXIST;
1784 goto error;
1785 }
1786 }
1787
1788 if (ret < 0) {
1789 ret = LTTCOMM_KERN_ENABLE_FAIL;
1790 goto error;
1791 }
1792
1793 kernel_wait_quiescent(kernel_tracer_fd);
1794 break;
1795 default:
1796 /* TODO: Userspace tracing */
1797 ret = LTTCOMM_NOT_IMPLEMENTED;
1798 goto error;
1799 }
1800 ret = LTTCOMM_OK;
1801 break;
1802 }
1803 case LTTNG_ENABLE_ALL_EVENT:
1804 {
1805 int size, i;
1806 char *channel_name;
1807 struct ltt_kernel_channel *kchan;
1808 struct ltt_kernel_event *kevent;
1809 struct lttng_event *event_list;
1810 struct lttng_channel *chan;
1811
1812 /* Setup lttng message with no payload */
1813 ret = setup_lttng_msg(cmd_ctx, 0);
1814 if (ret < 0) {
1815 goto setup_error;
1816 }
1817
1818 DBG("Enabling all kernel event");
1819
1820 channel_name = cmd_ctx->lsm->u.enable.channel_name;
1821
1822 switch (cmd_ctx->lsm->domain.type) {
1823 case LTTNG_DOMAIN_KERNEL:
1824 kchan = get_kernel_channel_by_name(channel_name,
1825 cmd_ctx->session->kernel_session);
1826 if (kchan == NULL) {
1827 DBG("Channel not found. Creating channel %s", channel_name);
1828
1829 chan = init_default_channel(cmd_ctx->lsm->domain.type, channel_name);
1830 if (chan == NULL) {
1831 ret = LTTCOMM_FATAL;
1832 goto error;
1833 }
1834
1835 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
1836 chan, cmd_ctx->session->kernel_session->trace_path);
1837 if (ret < 0) {
1838 ret = LTTCOMM_KERN_CHAN_FAIL;
1839 goto error;
1840 }
1841 kchan = get_kernel_channel_by_name(channel_name,
1842 cmd_ctx->session->kernel_session);
1843 if (kchan == NULL) {
1844 ERR("Channel %s not found after creation. Internal error, giving up.",
1845 channel_name);
1846 ret = LTTCOMM_FATAL;
1847 goto error;
1848 }
1849 }
1850
1851 /* For each event in the kernel session */
1852 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
1853 DBG("Enabling kernel event %s for channel %s.",
1854 kevent->event->name, channel_name);
1855 ret = kernel_enable_event(kevent);
1856 if (ret < 0) {
1857 continue;
1858 }
1859 }
1860
1861 size = kernel_list_events(kernel_tracer_fd, &event_list);
1862 if (size < 0) {
1863 ret = LTTCOMM_KERN_LIST_FAIL;
1864 goto error;
1865 }
1866
1867 for (i = 0; i < size; i++) {
1868 kevent = get_kernel_event_by_name(event_list[i].name, kchan);
1869 if (kevent == NULL) {
1870 /* Default event type for enable all */
1871 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
1872 /* Enable each single tracepoint event */
1873 ret = kernel_create_event(&event_list[i], kchan);
1874 if (ret < 0) {
1875 /* Ignore error here and continue */
1876 }
1877 }
1878 }
1879
1880 free(event_list);
1881
1882 /* Quiescent wait after event enable */
1883 kernel_wait_quiescent(kernel_tracer_fd);
1884 break;
1885 default:
1886 /* TODO: Userspace tracing */
1887 ret = LTTCOMM_NOT_IMPLEMENTED;
1888 goto error;
1889 }
1890
1891 ret = LTTCOMM_OK;
1892 break;
1893 }
1894 case LTTNG_LIST_TRACEPOINTS:
1895 {
1896 struct lttng_event *events;
1897 ssize_t nb_events = 0;
1898
1899 switch (cmd_ctx->lsm->domain.type) {
1900 case LTTNG_DOMAIN_KERNEL:
1901 DBG("Listing kernel events");
1902 nb_events = kernel_list_events(kernel_tracer_fd, &events);
1903 if (nb_events < 0) {
1904 ret = LTTCOMM_KERN_LIST_FAIL;
1905 goto error;
1906 }
1907 break;
1908 default:
1909 /* TODO: Userspace listing */
1910 ret = LTTCOMM_NOT_IMPLEMENTED;
1911 break;
1912 }
1913
1914 /*
1915 * Setup lttng message with payload size set to the event list size in
1916 * bytes and then copy list into the llm payload.
1917 */
1918 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
1919 if (ret < 0) {
1920 free(events);
1921 goto setup_error;
1922 }
1923
1924 /* Copy event list into message payload */
1925 memcpy(cmd_ctx->llm->payload, events,
1926 sizeof(struct lttng_event) * nb_events);
1927
1928 free(events);
1929
1930 ret = LTTCOMM_OK;
1931 break;
1932 }
1933 case LTTNG_START_TRACE:
1934 {
1935 struct ltt_kernel_channel *chan;
1936
1937 /* Setup lttng message with no payload */
1938 ret = setup_lttng_msg(cmd_ctx, 0);
1939 if (ret < 0) {
1940 goto setup_error;
1941 }
1942
1943 /* Kernel tracing */
1944 if (cmd_ctx->session->kernel_session != NULL) {
1945 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1946 DBG("Open kernel metadata");
1947 ret = kernel_open_metadata(cmd_ctx->session->kernel_session,
1948 cmd_ctx->session->kernel_session->trace_path);
1949 if (ret < 0) {
1950 ret = LTTCOMM_KERN_META_FAIL;
1951 goto error;
1952 }
1953 }
1954
1955 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1956 DBG("Opening kernel metadata stream");
1957 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1958 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1959 if (ret < 0) {
1960 ERR("Kernel create metadata stream failed");
1961 ret = LTTCOMM_KERN_STREAM_FAIL;
1962 goto error;
1963 }
1964 }
1965 }
1966
1967 /* For each channel */
1968 cds_list_for_each_entry(chan,
1969 &cmd_ctx->session->kernel_session->channel_list.head, list) {
1970 if (chan->stream_count == 0) {
1971 ret = kernel_open_channel_stream(chan);
1972 if (ret < 0) {
1973 ERR("Kernel create channel stream failed");
1974 ret = LTTCOMM_KERN_STREAM_FAIL;
1975 goto error;
1976 }
1977 /* Update the stream global counter */
1978 cmd_ctx->session->kernel_session->stream_count_global += ret;
1979 }
1980 }
1981
1982 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1983 if (ret < 0) {
1984 ret = LTTCOMM_KERN_START_FAIL;
1985 goto error;
1986 }
1987
1988 DBG("Start kernel tracing");
1989 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1990 if (ret < 0) {
1991 ERR("Kernel start session failed");
1992 ret = LTTCOMM_KERN_START_FAIL;
1993 goto error;
1994 }
1995
1996 /* Quiescent wait after starting trace */
1997 kernel_wait_quiescent(kernel_tracer_fd);
1998 }
1999
2000 /* TODO: Start all UST traces */
2001
2002 ret = LTTCOMM_OK;
2003 break;
2004 }
2005 case LTTNG_STOP_TRACE:
2006 {
2007 struct ltt_kernel_channel *chan;
2008 /* Setup lttng message with no payload */
2009 ret = setup_lttng_msg(cmd_ctx, 0);
2010 if (ret < 0) {
2011 goto setup_error;
2012 }
2013
2014 /* Kernel tracer */
2015 if (cmd_ctx->session->kernel_session != NULL) {
2016 DBG("Stop kernel tracing");
2017
2018 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
2019 if (ret < 0) {
2020 ERR("Kernel metadata flush failed");
2021 }
2022
2023 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
2024 ret = kernel_flush_buffer(chan);
2025 if (ret < 0) {
2026 ERR("Kernel flush buffer error");
2027 }
2028 }
2029
2030 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
2031 if (ret < 0) {
2032 ERR("Kernel stop session failed");
2033 ret = LTTCOMM_KERN_STOP_FAIL;
2034 goto error;
2035 }
2036
2037 /* Quiescent wait after stopping trace */
2038 kernel_wait_quiescent(kernel_tracer_fd);
2039 }
2040
2041 /* TODO : User-space tracer */
2042
2043 ret = LTTCOMM_OK;
2044 break;
2045 }
2046 case LTTNG_CREATE_SESSION:
2047 {
2048 /* Setup lttng message with no payload */
2049 ret = setup_lttng_msg(cmd_ctx, 0);
2050 if (ret < 0) {
2051 goto setup_error;
2052 }
2053
2054 ret = create_session(cmd_ctx->lsm->session.name, cmd_ctx->lsm->session.path);
2055 if (ret < 0) {
2056 if (ret == -EEXIST) {
2057 ret = LTTCOMM_EXIST_SESS;
2058 } else {
2059 ret = LTTCOMM_FATAL;
2060 }
2061 goto error;
2062 }
2063
2064 ret = LTTCOMM_OK;
2065 break;
2066 }
2067 case LTTNG_DESTROY_SESSION:
2068 {
2069 /* Setup lttng message with no payload */
2070 ret = setup_lttng_msg(cmd_ctx, 0);
2071 if (ret < 0) {
2072 goto setup_error;
2073 }
2074
2075 /* Clean kernel session teardown */
2076 teardown_kernel_session(cmd_ctx->session);
2077
2078 ret = destroy_session(cmd_ctx->lsm->session.name);
2079 if (ret < 0) {
2080 ret = LTTCOMM_FATAL;
2081 goto error;
2082 }
2083
2084 /*
2085 * Must notify the kernel thread here to update it's pollfd in order to
2086 * remove the channel(s)' fd just destroyed.
2087 */
2088 ret = notify_kernel_pollfd();
2089 if (ret < 0) {
2090 ret = LTTCOMM_FATAL;
2091 goto error;
2092 }
2093
2094 ret = LTTCOMM_OK;
2095 break;
2096 }
2097 case LTTNG_LIST_DOMAINS:
2098 {
2099 size_t nb_dom = 0;
2100
2101 if (cmd_ctx->session->kernel_session != NULL) {
2102 nb_dom++;
2103 }
2104
2105 nb_dom += cmd_ctx->session->ust_trace_count;
2106
2107 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_domain) * nb_dom);
2108 if (ret < 0) {
2109 goto setup_error;
2110 }
2111
2112 ((struct lttng_domain *)(cmd_ctx->llm->payload))[0].type =
2113 LTTNG_DOMAIN_KERNEL;
2114
2115 /* TODO: User-space tracer domain support */
2116 ret = LTTCOMM_OK;
2117 break;
2118 }
2119 case LTTNG_LIST_CHANNELS:
2120 {
2121 /*
2122 * TODO: Only kernel channels are listed here. UST listing
2123 * is needed on lttng-ust 2.0 release.
2124 */
2125 size_t nb_chan = 0;
2126 if (cmd_ctx->session->kernel_session != NULL) {
2127 nb_chan += cmd_ctx->session->kernel_session->channel_count;
2128 }
2129
2130 ret = setup_lttng_msg(cmd_ctx,
2131 sizeof(struct lttng_channel) * nb_chan);
2132 if (ret < 0) {
2133 goto setup_error;
2134 }
2135
2136 list_lttng_channels(cmd_ctx->session,
2137 (struct lttng_channel *)(cmd_ctx->llm->payload));
2138
2139 ret = LTTCOMM_OK;
2140 break;
2141 }
2142 case LTTNG_LIST_EVENTS:
2143 {
2144 /*
2145 * TODO: Only kernel events are listed here. UST listing
2146 * is needed on lttng-ust 2.0 release.
2147 */
2148 size_t nb_event = 0;
2149 struct ltt_kernel_channel *kchan = NULL;
2150
2151 if (cmd_ctx->session->kernel_session != NULL) {
2152 kchan = get_kernel_channel_by_name(cmd_ctx->lsm->u.list.channel_name,
2153 cmd_ctx->session->kernel_session);
2154 if (kchan == NULL) {
2155 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2156 goto error;
2157 }
2158 nb_event += kchan->event_count;
2159 }
2160
2161 ret = setup_lttng_msg(cmd_ctx,
2162 sizeof(struct lttng_event) * nb_event);
2163 if (ret < 0) {
2164 goto setup_error;
2165 }
2166
2167 DBG("Listing events (%zu events)", nb_event);
2168
2169 list_lttng_events(kchan,
2170 (struct lttng_event *)(cmd_ctx->llm->payload));
2171
2172 ret = LTTCOMM_OK;
2173 break;
2174 }
2175 case LTTNG_LIST_SESSIONS:
2176 {
2177 lock_session_list();
2178
2179 if (session_list_ptr->count == 0) {
2180 ret = LTTCOMM_NO_SESSION;
2181 unlock_session_list();
2182 goto error;
2183 }
2184
2185 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
2186 session_list_ptr->count);
2187 if (ret < 0) {
2188 unlock_session_list();
2189 goto setup_error;
2190 }
2191
2192 /* Filled the session array */
2193 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
2194
2195 unlock_session_list();
2196
2197 ret = LTTCOMM_OK;
2198 break;
2199 }
2200 case LTTNG_CALIBRATE:
2201 {
2202 /* Setup lttng message with no payload */
2203 ret = setup_lttng_msg(cmd_ctx, 0);
2204 if (ret < 0) {
2205 goto setup_error;
2206 }
2207
2208 switch (cmd_ctx->lsm->domain.type) {
2209 case LTTNG_DOMAIN_KERNEL:
2210 {
2211 struct lttng_kernel_calibrate kcalibrate;
2212
2213 kcalibrate.type = cmd_ctx->lsm->u.calibrate.type;
2214 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2215 if (ret < 0) {
2216 ret = LTTCOMM_KERN_ENABLE_FAIL;
2217 goto error;
2218 }
2219 break;
2220 }
2221 default:
2222 /* TODO: Userspace tracing */
2223 ret = LTTCOMM_NOT_IMPLEMENTED;
2224 goto error;
2225 }
2226 ret = LTTCOMM_OK;
2227 break;
2228 }
2229 case LTTNG_REGISTER_CONSUMER:
2230 {
2231 int sock;
2232
2233 /* Setup lttng message with no payload */
2234 ret = setup_lttng_msg(cmd_ctx, 0);
2235 if (ret < 0) {
2236 goto setup_error;
2237 }
2238
2239 switch (cmd_ctx->lsm->domain.type) {
2240 case LTTNG_DOMAIN_KERNEL:
2241 {
2242 /* Can't register a consumer if there is already one */
2243 if (cmd_ctx->session->kernel_session->consumer_fd != 0) {
2244 ret = LTTCOMM_CONNECT_FAIL;
2245 goto error;
2246 }
2247
2248 sock = lttcomm_connect_unix_sock(cmd_ctx->lsm->u.reg.path);
2249 if (sock < 0) {
2250 ret = LTTCOMM_CONNECT_FAIL;
2251 goto error;
2252 }
2253
2254 cmd_ctx->session->kernel_session->consumer_fd = sock;
2255 break;
2256 }
2257 default:
2258 /* TODO: Userspace tracing */
2259 ret = LTTCOMM_NOT_IMPLEMENTED;
2260 goto error;
2261 }
2262
2263 ret = LTTCOMM_OK;
2264 break;
2265 }
2266
2267 default:
2268 /* Undefined command */
2269 ret = setup_lttng_msg(cmd_ctx, 0);
2270 if (ret < 0) {
2271 goto setup_error;
2272 }
2273
2274 ret = LTTCOMM_UND;
2275 break;
2276 }
2277
2278 /* Set return code */
2279 cmd_ctx->llm->ret_code = ret;
2280
2281 if (cmd_ctx->session) {
2282 unlock_session(cmd_ctx->session);
2283 }
2284
2285 return ret;
2286
2287 error:
2288 if (cmd_ctx->llm == NULL) {
2289 DBG("Missing llm structure. Allocating one.");
2290 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
2291 goto setup_error;
2292 }
2293 }
2294 /* Notify client of error */
2295 cmd_ctx->llm->ret_code = ret;
2296
2297 setup_error:
2298 if (cmd_ctx->session) {
2299 unlock_session(cmd_ctx->session);
2300 }
2301 return ret;
2302 }
2303
2304 /*
2305 * This thread manage all clients request using the unix client socket for
2306 * communication.
2307 */
2308 static void *thread_manage_clients(void *data)
2309 {
2310 int sock = 0, ret;
2311 struct command_ctx *cmd_ctx = NULL;
2312 struct pollfd pollfd[2];
2313
2314 DBG("[thread] Manage client started");
2315
2316 ret = lttcomm_listen_unix_sock(client_sock);
2317 if (ret < 0) {
2318 goto error;
2319 }
2320
2321 /* First fd is always the quit pipe */
2322 pollfd[0].fd = thread_quit_pipe[0];
2323
2324 /* Apps socket */
2325 pollfd[1].fd = client_sock;
2326 pollfd[1].events = POLLIN;
2327
2328 /* Notify parent pid that we are ready
2329 * to accept command for client side.
2330 */
2331 if (opt_sig_parent) {
2332 kill(ppid, SIGCHLD);
2333 }
2334
2335 while (1) {
2336 DBG("Accepting client command ...");
2337
2338 /* Inifinite blocking call, waiting for transmission */
2339 ret = poll(pollfd, 2, -1);
2340 if (ret < 0) {
2341 perror("poll client thread");
2342 goto error;
2343 }
2344
2345 /* Thread quit pipe has been closed. Killing thread. */
2346 if (pollfd[0].revents == POLLNVAL) {
2347 goto error;
2348 } else if (pollfd[1].revents == POLLERR) {
2349 ERR("Client socket poll error");
2350 goto error;
2351 }
2352
2353 sock = lttcomm_accept_unix_sock(client_sock);
2354 if (sock < 0) {
2355 goto error;
2356 }
2357
2358 /* Allocate context command to process the client request */
2359 cmd_ctx = malloc(sizeof(struct command_ctx));
2360
2361 /* Allocate data buffer for reception */
2362 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
2363 cmd_ctx->llm = NULL;
2364 cmd_ctx->session = NULL;
2365
2366 /*
2367 * Data is received from the lttng client. The struct
2368 * lttcomm_session_msg (lsm) contains the command and data request of
2369 * the client.
2370 */
2371 DBG("Receiving data from client ...");
2372 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
2373 if (ret <= 0) {
2374 continue;
2375 }
2376
2377 // TODO: Validate cmd_ctx including sanity check for security purpose.
2378
2379 /*
2380 * This function dispatch the work to the kernel or userspace tracer
2381 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2382 * informations for the client. The command context struct contains
2383 * everything this function may needs.
2384 */
2385 ret = process_client_msg(cmd_ctx);
2386 if (ret < 0) {
2387 /* TODO: Inform client somehow of the fatal error. At this point,
2388 * ret < 0 means that a malloc failed (ENOMEM). */
2389 /* Error detected but still accept command */
2390 clean_command_ctx(&cmd_ctx);
2391 continue;
2392 }
2393
2394 DBG("Sending response (size: %d, retcode: %d)",
2395 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
2396 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
2397 if (ret < 0) {
2398 ERR("Failed to send data back to client");
2399 }
2400
2401 clean_command_ctx(&cmd_ctx);
2402
2403 /* End of transmission */
2404 close(sock);
2405 }
2406
2407 error:
2408 DBG("Client thread dying");
2409 if (client_sock) {
2410 close(client_sock);
2411 }
2412 if (sock) {
2413 close(sock);
2414 }
2415
2416 unlink(client_unix_sock_path);
2417
2418 clean_command_ctx(&cmd_ctx);
2419 return NULL;
2420 }
2421
2422
2423 /*
2424 * usage function on stderr
2425 */
2426 static void usage(void)
2427 {
2428 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
2429 fprintf(stderr, " -h, --help Display this usage.\n");
2430 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
2431 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2432 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2433 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2434 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
2435 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2436 fprintf(stderr, " -V, --version Show version number.\n");
2437 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2438 fprintf(stderr, " -q, --quiet No output at all.\n");
2439 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2440 fprintf(stderr, " --verbose-kconsumerd Verbose mode for kconsumerd. Activate DBG() macro.\n");
2441 }
2442
2443 /*
2444 * daemon argument parsing
2445 */
2446 static int parse_args(int argc, char **argv)
2447 {
2448 int c;
2449
2450 static struct option long_options[] = {
2451 { "client-sock", 1, 0, 'c' },
2452 { "apps-sock", 1, 0, 'a' },
2453 { "kconsumerd-cmd-sock", 1, 0, 0 },
2454 { "kconsumerd-err-sock", 1, 0, 0 },
2455 { "daemonize", 0, 0, 'd' },
2456 { "sig-parent", 0, 0, 'S' },
2457 { "help", 0, 0, 'h' },
2458 { "group", 1, 0, 'g' },
2459 { "version", 0, 0, 'V' },
2460 { "quiet", 0, 0, 'q' },
2461 { "verbose", 0, 0, 'v' },
2462 { "verbose-kconsumerd", 0, 0, 'Z' },
2463 { NULL, 0, 0, 0 }
2464 };
2465
2466 while (1) {
2467 int option_index = 0;
2468 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:Z", long_options, &option_index);
2469 if (c == -1) {
2470 break;
2471 }
2472
2473 switch (c) {
2474 case 0:
2475 fprintf(stderr, "option %s", long_options[option_index].name);
2476 if (optarg) {
2477 fprintf(stderr, " with arg %s\n", optarg);
2478 }
2479 break;
2480 case 'c':
2481 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
2482 break;
2483 case 'a':
2484 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
2485 break;
2486 case 'd':
2487 opt_daemon = 1;
2488 break;
2489 case 'g':
2490 opt_tracing_group = strdup(optarg);
2491 break;
2492 case 'h':
2493 usage();
2494 exit(EXIT_FAILURE);
2495 case 'V':
2496 fprintf(stdout, "%s\n", VERSION);
2497 exit(EXIT_SUCCESS);
2498 case 'S':
2499 opt_sig_parent = 1;
2500 break;
2501 case 'E':
2502 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
2503 break;
2504 case 'C':
2505 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
2506 break;
2507 case 'q':
2508 opt_quiet = 1;
2509 break;
2510 case 'v':
2511 /* Verbose level can increase using multiple -v */
2512 opt_verbose += 1;
2513 break;
2514 case 'Z':
2515 opt_verbose_kconsumerd += 1;
2516 break;
2517 default:
2518 /* Unknown option or other error.
2519 * Error is printed by getopt, just return */
2520 return -1;
2521 }
2522 }
2523
2524 return 0;
2525 }
2526
2527 /*
2528 * Creates the two needed socket by the daemon.
2529 * apps_sock - The communication socket for all UST apps.
2530 * client_sock - The communication of the cli tool (lttng).
2531 */
2532 static int init_daemon_socket(void)
2533 {
2534 int ret = 0;
2535 mode_t old_umask;
2536
2537 old_umask = umask(0);
2538
2539 /* Create client tool unix socket */
2540 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
2541 if (client_sock < 0) {
2542 ERR("Create unix sock failed: %s", client_unix_sock_path);
2543 ret = -1;
2544 goto end;
2545 }
2546
2547 /* File permission MUST be 660 */
2548 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2549 if (ret < 0) {
2550 ERR("Set file permissions failed: %s", client_unix_sock_path);
2551 perror("chmod");
2552 goto end;
2553 }
2554
2555 /* Create the application unix socket */
2556 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
2557 if (apps_sock < 0) {
2558 ERR("Create unix sock failed: %s", apps_unix_sock_path);
2559 ret = -1;
2560 goto end;
2561 }
2562
2563 /* File permission MUST be 666 */
2564 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
2565 if (ret < 0) {
2566 ERR("Set file permissions failed: %s", apps_unix_sock_path);
2567 perror("chmod");
2568 goto end;
2569 }
2570
2571 end:
2572 umask(old_umask);
2573 return ret;
2574 }
2575
2576 /*
2577 * Check if the global socket is available, and if a daemon is answering
2578 * at the other side. If yes, error is returned.
2579 */
2580 static int check_existing_daemon(void)
2581 {
2582 if (access(client_unix_sock_path, F_OK) < 0 &&
2583 access(apps_unix_sock_path, F_OK) < 0)
2584 return 0;
2585 /* Is there anybody out there ? */
2586 if (lttng_session_daemon_alive())
2587 return -EEXIST;
2588 else
2589 return 0;
2590 }
2591
2592 /*
2593 * Set the tracing group gid onto the client socket.
2594 *
2595 * Race window between mkdir and chown is OK because we are going from more
2596 * permissive (root.root) to les permissive (root.tracing).
2597 */
2598 static int set_permissions(void)
2599 {
2600 int ret;
2601 gid_t gid;
2602
2603 gid = allowed_group();
2604 if (gid < 0) {
2605 if (is_root) {
2606 WARN("No tracing group detected");
2607 ret = 0;
2608 } else {
2609 ERR("Missing tracing group. Aborting execution.");
2610 ret = -1;
2611 }
2612 goto end;
2613 }
2614
2615 /* Set lttng run dir */
2616 ret = chown(LTTNG_RUNDIR, 0, gid);
2617 if (ret < 0) {
2618 ERR("Unable to set group on " LTTNG_RUNDIR);
2619 perror("chown");
2620 }
2621
2622 /* lttng client socket path */
2623 ret = chown(client_unix_sock_path, 0, gid);
2624 if (ret < 0) {
2625 ERR("Unable to set group on %s", client_unix_sock_path);
2626 perror("chown");
2627 }
2628
2629 /* kconsumerd error socket path */
2630 ret = chown(kconsumerd_err_unix_sock_path, 0, gid);
2631 if (ret < 0) {
2632 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
2633 perror("chown");
2634 }
2635
2636 DBG("All permissions are set");
2637
2638 end:
2639 return ret;
2640 }
2641
2642 /*
2643 * Create the pipe used to wake up the kernel thread.
2644 */
2645 static int create_kernel_poll_pipe(void)
2646 {
2647 return pipe2(kernel_poll_pipe, O_CLOEXEC);
2648 }
2649
2650 /*
2651 * Create the lttng run directory needed for all global sockets and pipe.
2652 */
2653 static int create_lttng_rundir(void)
2654 {
2655 int ret;
2656
2657 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
2658 if (ret < 0) {
2659 if (errno != EEXIST) {
2660 ERR("Unable to create " LTTNG_RUNDIR);
2661 goto error;
2662 } else {
2663 ret = 0;
2664 }
2665 }
2666
2667 error:
2668 return ret;
2669 }
2670
2671 /*
2672 * Setup sockets and directory needed by the kconsumerd communication with the
2673 * session daemon.
2674 */
2675 static int set_kconsumerd_sockets(void)
2676 {
2677 int ret;
2678
2679 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
2680 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
2681 }
2682
2683 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
2684 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
2685 }
2686
2687 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
2688 if (ret < 0) {
2689 if (errno != EEXIST) {
2690 ERR("Failed to create " KCONSUMERD_PATH);
2691 goto error;
2692 }
2693 ret = 0;
2694 }
2695
2696 /* Create the kconsumerd error unix socket */
2697 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
2698 if (kconsumerd_err_sock < 0) {
2699 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
2700 ret = -1;
2701 goto error;
2702 }
2703
2704 /* File permission MUST be 660 */
2705 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2706 if (ret < 0) {
2707 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
2708 perror("chmod");
2709 goto error;
2710 }
2711
2712 error:
2713 return ret;
2714 }
2715
2716 /*
2717 * Signal handler for the daemon
2718 *
2719 * Simply stop all worker threads, leaving main() return gracefully
2720 * after joining all threads and calling cleanup().
2721 */
2722 static void sighandler(int sig)
2723 {
2724 switch (sig) {
2725 case SIGPIPE:
2726 DBG("SIGPIPE catched");
2727 return;
2728 case SIGINT:
2729 DBG("SIGINT catched");
2730 stop_threads();
2731 break;
2732 case SIGTERM:
2733 DBG("SIGTERM catched");
2734 stop_threads();
2735 break;
2736 default:
2737 break;
2738 }
2739 }
2740
2741 /*
2742 * Setup signal handler for :
2743 * SIGINT, SIGTERM, SIGPIPE
2744 */
2745 static int set_signal_handler(void)
2746 {
2747 int ret = 0;
2748 struct sigaction sa;
2749 sigset_t sigset;
2750
2751 if ((ret = sigemptyset(&sigset)) < 0) {
2752 perror("sigemptyset");
2753 return ret;
2754 }
2755
2756 sa.sa_handler = sighandler;
2757 sa.sa_mask = sigset;
2758 sa.sa_flags = 0;
2759 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
2760 perror("sigaction");
2761 return ret;
2762 }
2763
2764 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
2765 perror("sigaction");
2766 return ret;
2767 }
2768
2769 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
2770 perror("sigaction");
2771 return ret;
2772 }
2773
2774 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2775
2776 return ret;
2777 }
2778
2779 /*
2780 * Set open files limit to unlimited. This daemon can open a large number of
2781 * file descriptors in order to consumer multiple kernel traces.
2782 */
2783 static void set_ulimit(void)
2784 {
2785 int ret;
2786 struct rlimit lim;
2787
2788 /* The kernel does not allowed an infinite limit for open files */
2789 lim.rlim_cur = 65535;
2790 lim.rlim_max = 65535;
2791
2792 ret = setrlimit(RLIMIT_NOFILE, &lim);
2793 if (ret < 0) {
2794 perror("failed to set open files limit");
2795 }
2796 }
2797
2798 /*
2799 * main
2800 */
2801 int main(int argc, char **argv)
2802 {
2803 int ret = 0;
2804 void *status;
2805 const char *home_path;
2806
2807 /* Create thread quit pipe */
2808 if ((ret = init_thread_quit_pipe()) < 0) {
2809 goto error;
2810 }
2811
2812 /* Parse arguments */
2813 progname = argv[0];
2814 if ((ret = parse_args(argc, argv) < 0)) {
2815 goto error;
2816 }
2817
2818 /* Daemonize */
2819 if (opt_daemon) {
2820 ret = daemon(0, 0);
2821 if (ret < 0) {
2822 perror("daemon");
2823 goto error;
2824 }
2825 }
2826
2827 /* Check if daemon is UID = 0 */
2828 is_root = !getuid();
2829
2830 if (is_root) {
2831 ret = create_lttng_rundir();
2832 if (ret < 0) {
2833 goto error;
2834 }
2835
2836 if (strlen(apps_unix_sock_path) == 0) {
2837 snprintf(apps_unix_sock_path, PATH_MAX,
2838 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
2839 }
2840
2841 if (strlen(client_unix_sock_path) == 0) {
2842 snprintf(client_unix_sock_path, PATH_MAX,
2843 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
2844 }
2845 } else {
2846 home_path = get_home_dir();
2847 if (home_path == NULL) {
2848 /* TODO: Add --socket PATH option */
2849 ERR("Can't get HOME directory for sockets creation.");
2850 ret = -EPERM;
2851 goto error;
2852 }
2853
2854 if (strlen(apps_unix_sock_path) == 0) {
2855 snprintf(apps_unix_sock_path, PATH_MAX,
2856 DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
2857 }
2858
2859 /* Set the cli tool unix socket path */
2860 if (strlen(client_unix_sock_path) == 0) {
2861 snprintf(client_unix_sock_path, PATH_MAX,
2862 DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
2863 }
2864 }
2865
2866 DBG("Client socket path %s", client_unix_sock_path);
2867 DBG("Application socket path %s", apps_unix_sock_path);
2868
2869 /*
2870 * See if daemon already exist.
2871 */
2872 if ((ret = check_existing_daemon()) < 0) {
2873 ERR("Already running daemon.\n");
2874 /*
2875 * We do not goto exit because we must not cleanup()
2876 * because a daemon is already running.
2877 */
2878 goto error;
2879 }
2880
2881 /* After this point, we can safely call cleanup() so goto error is used */
2882
2883 /*
2884 * These actions must be executed as root. We do that *after* setting up
2885 * the sockets path because we MUST make the check for another daemon using
2886 * those paths *before* trying to set the kernel consumer sockets and init
2887 * kernel tracer.
2888 */
2889 if (is_root) {
2890 ret = set_kconsumerd_sockets();
2891 if (ret < 0) {
2892 goto exit;
2893 }
2894
2895 /* Setup kernel tracer */
2896 init_kernel_tracer();
2897
2898 /* Set ulimit for open files */
2899 set_ulimit();
2900 }
2901
2902 if ((ret = set_signal_handler()) < 0) {
2903 goto exit;
2904 }
2905
2906 /* Setup the needed unix socket */
2907 if ((ret = init_daemon_socket()) < 0) {
2908 goto exit;
2909 }
2910
2911 /* Set credentials to socket */
2912 if (is_root && ((ret = set_permissions()) < 0)) {
2913 goto exit;
2914 }
2915
2916 /* Get parent pid if -S, --sig-parent is specified. */
2917 if (opt_sig_parent) {
2918 ppid = getppid();
2919 }
2920
2921 /* Setup the kernel pipe for waking up the kernel thread */
2922 if ((ret = create_kernel_poll_pipe()) < 0) {
2923 goto exit;
2924 }
2925
2926 /*
2927 * Get session list pointer. This pointer MUST NOT be free().
2928 * This list is statically declared in session.c
2929 */
2930 session_list_ptr = get_session_list();
2931
2932 /* Create thread to manage the client socket */
2933 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
2934 if (ret != 0) {
2935 perror("pthread_create");
2936 goto exit_client;
2937 }
2938
2939 /* Create thread to manage application socket */
2940 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
2941 if (ret != 0) {
2942 perror("pthread_create");
2943 goto exit_apps;
2944 }
2945
2946 /* Create kernel thread to manage kernel event */
2947 ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
2948 if (ret != 0) {
2949 perror("pthread_create");
2950 goto exit_kernel;
2951 }
2952
2953 ret = pthread_join(kernel_thread, &status);
2954 if (ret != 0) {
2955 perror("pthread_join");
2956 goto error; /* join error, exit without cleanup */
2957 }
2958
2959 exit_kernel:
2960 ret = pthread_join(apps_thread, &status);
2961 if (ret != 0) {
2962 perror("pthread_join");
2963 goto error; /* join error, exit without cleanup */
2964 }
2965
2966 exit_apps:
2967 ret = pthread_join(client_thread, &status);
2968 if (ret != 0) {
2969 perror("pthread_join");
2970 goto error; /* join error, exit without cleanup */
2971 }
2972
2973 ret = join_kconsumerd_thread();
2974 if (ret != 0) {
2975 perror("join_kconsumerd");
2976 goto error; /* join error, exit without cleanup */
2977 }
2978
2979 exit_client:
2980 exit:
2981 /*
2982 * cleanup() is called when no other thread is running.
2983 */
2984 cleanup();
2985 if (!ret)
2986 exit(EXIT_SUCCESS);
2987 error:
2988 exit(EXIT_FAILURE);
2989 }
This page took 0.156334 seconds and 3 git commands to generate.