cbd6a3f3f6a7469ddc2be72fb5b313555bf37989
[lttng-tools.git] / ltt-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <grp.h>
23 #include <limits.h>
24 #include <pthread.h>
25 #include <semaphore.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sys/ipc.h>
31 #include <sys/shm.h>
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35 #include <unistd.h>
36
37 #include <urcu/list.h> /* URCU list library (-lurcu) */
38 #include <ust/ustctl.h> /* UST control lib (-lust) */
39 #include <lttng/lttng.h>
40
41 #include "liblttsessiondcomm.h"
42 #include "ltt-sessiond.h"
43 #include "lttngerr.h"
44 #include "kernel-ctl.h"
45 #include "ust-ctl.h"
46 #include "session.h"
47 #include "traceable-app.h"
48 #include "lttng-kconsumerd.h"
49
50 /*
51 * TODO:
52 * teardown: signal SIGTERM handler -> write into pipe. Threads waits
53 * with epoll on pipe and on other pipes/sockets for commands. Main
54 * simply waits on pthread join.
55 */
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_quiet; /* Not static for lttngerr.h */
66 const char *progname;
67 const char *opt_tracing_group;
68 static int opt_sig_parent;
69 static int opt_daemon;
70 static int is_root; /* Set to 1 if the daemon is running as root */
71 static pid_t ppid; /* Parent PID for --sig-parent option */
72 static pid_t kconsumerd_pid;
73
74 static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
75 static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
76 static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
77 static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
78
79 /* Sockets and FDs */
80 static int client_sock;
81 static int apps_sock;
82 static int kconsumerd_err_sock;
83 static int kconsumerd_cmd_sock;
84 static int kernel_tracer_fd;
85
86 /* Pthread, Mutexes and Semaphores */
87 static pthread_t kconsumerd_thread;
88 static pthread_t apps_thread;
89 static pthread_t client_thread;
90 static sem_t kconsumerd_sem;
91
92 static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
93
94 /*
95 * teardown_kernel_session
96 *
97 * Complete teardown of a kernel session. This free all data structure
98 * related to a kernel session and update counter.
99 */
100 static void teardown_kernel_session(struct ltt_session *session)
101 {
102 if (session->kernel_session != NULL) {
103 DBG("Tearing down kernel session");
104 trace_destroy_kernel_session(session->kernel_session);
105 /* Extra precaution */
106 session->kernel_session = NULL;
107 /* Decrement session count */
108 session->kern_session_count--;
109 }
110 }
111
112 /*
113 * cleanup
114 *
115 * Cleanup the daemon on exit
116 */
117 static void cleanup()
118 {
119 int ret;
120 char *cmd;
121 struct ltt_session *sess;
122
123 DBG("Cleaning up");
124
125 /* <fun> */
126 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
127 MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0);
128 /* </fun> */
129
130 /* Stopping all threads */
131 DBG("Terminating all threads");
132 pthread_cancel(client_thread);
133 pthread_cancel(apps_thread);
134 if (kconsumerd_pid != 0) {
135 pthread_cancel(kconsumerd_thread);
136 }
137
138 DBG("Unlinking all unix socket");
139 unlink(client_unix_sock_path);
140 unlink(apps_unix_sock_path);
141 unlink(kconsumerd_err_unix_sock_path);
142
143 DBG("Removing %s directory", LTTNG_RUNDIR);
144 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
145 if (ret < 0) {
146 ERR("asprintf failed. Something is really wrong!");
147 }
148
149 /* Remove lttng run directory */
150 ret = system(cmd);
151 if (ret < 0) {
152 ERR("Unable to clean " LTTNG_RUNDIR);
153 }
154
155 DBG("Cleaning up all session");
156 /* Cleanup ALL session */
157 cds_list_for_each_entry(sess, &ltt_session_list.head, list) {
158 teardown_kernel_session(sess);
159 // TODO complete session cleanup (including UST)
160 }
161
162 close(kernel_tracer_fd);
163 }
164
165 /*
166 * send_unix_sock
167 *
168 * Send data on a unix socket using the liblttsessiondcomm API.
169 *
170 * Return lttcomm error code.
171 */
172 static int send_unix_sock(int sock, void *buf, size_t len)
173 {
174 /* Check valid length */
175 if (len <= 0) {
176 return -1;
177 }
178
179 return lttcomm_send_unix_sock(sock, buf, len);
180 }
181
182 /*
183 * clean_command_ctx
184 *
185 * Free memory of a command context structure.
186 */
187 static void clean_command_ctx(struct command_ctx *cmd_ctx)
188 {
189 DBG("Clean command context structure %p", cmd_ctx);
190 if (cmd_ctx) {
191 if (cmd_ctx->llm) {
192 free(cmd_ctx->llm);
193 }
194 if (cmd_ctx->lsm) {
195 free(cmd_ctx->lsm);
196 }
197 free(cmd_ctx);
198 cmd_ctx = NULL;
199 }
200 }
201
202 /*
203 * ust_connect_app
204 *
205 * Return a socket connected to the libust communication socket
206 * of the application identified by the pid.
207 *
208 * If the pid is not found in the traceable list,
209 * return -1 to indicate error.
210 */
211 static int ust_connect_app(pid_t pid)
212 {
213 int sock;
214 struct ltt_traceable_app *lta;
215
216 DBG("Connect to application pid %d", pid);
217
218 lta = find_app_by_pid(pid);
219 if (lta == NULL) {
220 /* App not found */
221 DBG("Application pid %d not found", pid);
222 return -1;
223 }
224
225 sock = ustctl_connect_pid(lta->pid);
226 if (sock < 0) {
227 ERR("Fail connecting to the PID %d\n", pid);
228 }
229
230 return sock;
231 }
232
233 /*
234 * notify_apps
235 *
236 * Notify apps by writing 42 to a named pipe using name.
237 * Every applications waiting for a ltt-sessiond will be notified
238 * and re-register automatically to the session daemon.
239 *
240 * Return open or write error value.
241 */
242 static int notify_apps(const char *name)
243 {
244 int fd;
245 int ret = -1;
246
247 DBG("Notify the global application pipe");
248
249 /* Try opening the global pipe */
250 fd = open(name, O_WRONLY);
251 if (fd < 0) {
252 goto error;
253 }
254
255 /* Notify by writing on the pipe */
256 ret = write(fd, "42", 2);
257 if (ret < 0) {
258 perror("write");
259 }
260
261 error:
262 return ret;
263 }
264
265 /*
266 * setup_lttng_msg
267 *
268 * Setup the outgoing data buffer for the response (llm) by allocating the
269 * right amount of memory and copying the original information from the lsm
270 * structure.
271 *
272 * Return total size of the buffer pointed by buf.
273 */
274 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
275 {
276 int ret, buf_size, trace_name_size;
277
278 /*
279 * Check for the trace_name. If defined, it's part of the payload data of
280 * the llm structure.
281 */
282 trace_name_size = strlen(cmd_ctx->lsm->trace_name);
283 buf_size = trace_name_size + size;
284
285 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
286 if (cmd_ctx->llm == NULL) {
287 perror("malloc");
288 ret = -ENOMEM;
289 goto error;
290 }
291
292 /* Copy common data */
293 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
294 cmd_ctx->llm->pid = cmd_ctx->lsm->pid;
295 if (!uuid_is_null(cmd_ctx->lsm->session_uuid)) {
296 uuid_copy(cmd_ctx->llm->session_uuid, cmd_ctx->lsm->session_uuid);
297 }
298
299 cmd_ctx->llm->trace_name_offset = trace_name_size;
300 cmd_ctx->llm->data_size = size;
301 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
302
303 /* Copy trace name to the llm structure. Begining of the payload. */
304 memcpy(cmd_ctx->llm->payload, cmd_ctx->lsm->trace_name, trace_name_size);
305
306 return buf_size;
307
308 error:
309 return ret;
310 }
311
312 /*
313 * thread_manage_kconsumerd
314 *
315 * This thread manage the kconsumerd error sent
316 * back to the session daemon.
317 */
318 static void *thread_manage_kconsumerd(void *data)
319 {
320 int sock, ret;
321 enum lttcomm_return_code code;
322
323 DBG("[thread] Manage kconsumerd started");
324
325 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
326 if (ret < 0) {
327 goto error;
328 }
329
330 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
331 if (sock < 0) {
332 goto error;
333 }
334
335 /* Getting status code from kconsumerd */
336 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
337 if (ret <= 0) {
338 goto error;
339 }
340
341 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
342 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
343 if (kconsumerd_cmd_sock < 0) {
344 sem_post(&kconsumerd_sem);
345 perror("kconsumerd connect");
346 goto error;
347 }
348 /* Signal condition to tell that the kconsumerd is ready */
349 sem_post(&kconsumerd_sem);
350 DBG("Kconsumerd command socket ready");
351 } else {
352 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
353 lttcomm_get_readable_code(-code));
354 goto error;
355 }
356
357 /* Wait for any kconsumerd error */
358 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
359 if (ret <= 0) {
360 ERR("Kconsumerd closed the command socket");
361 goto error;
362 }
363
364 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
365
366 error:
367 kconsumerd_pid = 0;
368 DBG("Kconsumerd thread dying");
369 return NULL;
370 }
371
372 /*
373 * thread_manage_apps
374 *
375 * This thread manage the application socket communication
376 */
377 static void *thread_manage_apps(void *data)
378 {
379 int sock, ret;
380
381 /* TODO: Something more elegant is needed but fine for now */
382 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
383 * for 32-bit vs 64-bit compat processes. */
384 /* replicate in ust with version number */
385 struct {
386 int reg; /* 1:register, 0:unregister */
387 pid_t pid;
388 uid_t uid;
389 } reg_msg;
390
391 DBG("[thread] Manage apps started");
392
393 ret = lttcomm_listen_unix_sock(apps_sock);
394 if (ret < 0) {
395 goto error;
396 }
397
398 /* Notify all applications to register */
399 notify_apps(default_global_apps_pipe);
400
401 while (1) {
402 DBG("Accepting application registration");
403 /* Blocking call, waiting for transmission */
404 sock = lttcomm_accept_unix_sock(apps_sock);
405 if (sock < 0) {
406 goto error;
407 }
408
409 /* Basic recv here to handle the very simple data
410 * that the libust send to register (reg_msg).
411 */
412 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
413 if (ret < 0) {
414 perror("recv");
415 continue;
416 }
417
418 /* Add application to the global traceable list */
419 if (reg_msg.reg == 1) {
420 /* Registering */
421 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
422 if (ret < 0) {
423 /* register_traceable_app only return an error with
424 * ENOMEM. At this point, we better stop everything.
425 */
426 goto error;
427 }
428 } else {
429 /* Unregistering */
430 unregister_traceable_app(reg_msg.pid);
431 }
432 }
433
434 error:
435
436 return NULL;
437 }
438
439 /*
440 * spawn_kconsumerd_thread
441 *
442 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
443 * exec or it will fails.
444 */
445 static int spawn_kconsumerd_thread(void)
446 {
447 int ret;
448
449 /* Setup semaphore */
450 sem_init(&kconsumerd_sem, 0, 0);
451
452 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
453 if (ret != 0) {
454 perror("pthread_create kconsumerd");
455 goto error;
456 }
457
458 /* Wait for the kconsumerd thread to be ready */
459 sem_wait(&kconsumerd_sem);
460
461 if (kconsumerd_pid == 0) {
462 ERR("Kconsumerd did not start");
463 goto error;
464 }
465
466 return 0;
467
468 error:
469 ret = LTTCOMM_KERN_CONSUMER_FAIL;
470 return ret;
471 }
472
473 /*
474 * spawn_kconsumerd
475 *
476 * Fork and exec a kernel consumer daemon (kconsumerd).
477 *
478 * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel
479 * file descriptor using the libkernelctl or kernel-ctl functions. So, a
480 * kernel consumer MUST only be spawned before creating a kernel session.
481 *
482 * Return pid if successful else -1.
483 */
484 static pid_t spawn_kconsumerd(void)
485 {
486 int ret;
487 pid_t pid;
488
489 DBG("Spawning kconsumerd");
490
491 pid = fork();
492 if (pid == 0) {
493 /*
494 * Exec kconsumerd.
495 */
496 execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
497 if (errno != 0) {
498 perror("kernel start consumer exec");
499 }
500 exit(EXIT_FAILURE);
501 } else if (pid > 0) {
502 ret = pid;
503 goto error;
504 } else {
505 perror("kernel start consumer fork");
506 ret = -errno;
507 goto error;
508 }
509
510 error:
511 return ret;
512 }
513
514 /*
515 * start_kconsumerd
516 *
517 * Spawn the kconsumerd daemon and session daemon thread.
518 */
519 static int start_kconsumerd(void)
520 {
521 int ret;
522
523 pthread_mutex_lock(&kconsumerd_pid_mutex);
524 if (kconsumerd_pid != 0) {
525 goto end;
526 }
527
528 ret = spawn_kconsumerd();
529 if (ret < 0) {
530 ERR("Spawning kconsumerd failed");
531 ret = LTTCOMM_KERN_CONSUMER_FAIL;
532 pthread_mutex_unlock(&kconsumerd_pid_mutex);
533 goto error;
534 }
535
536 /* Setting up the global kconsumerd_pid */
537 kconsumerd_pid = ret;
538 pthread_mutex_unlock(&kconsumerd_pid_mutex);
539
540 DBG("Kconsumerd pid %d", ret);
541
542 DBG("Spawning kconsumerd thread");
543 ret = spawn_kconsumerd_thread();
544 if (ret < 0) {
545 ERR("Fatal error spawning kconsumerd thread");
546 goto error;
547 }
548
549 end:
550 pthread_mutex_unlock(&kconsumerd_pid_mutex);
551 return 0;
552
553 error:
554 return ret;
555 }
556
557 /*
558 * send_kconsumerd_fds
559 *
560 * Send all stream fds of the kernel session to the consumer.
561 */
562 static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
563 {
564 int ret;
565 size_t nb_fd;
566 struct ltt_kernel_stream *stream;
567 struct ltt_kernel_channel *chan;
568 struct lttcomm_kconsumerd_header lkh;
569 struct lttcomm_kconsumerd_msg lkm;
570
571 nb_fd = session->stream_count_global;
572
573 /* Setup header */
574 lkh.payload_size = (nb_fd + 1) * sizeof(struct lttcomm_kconsumerd_msg);
575 lkh.cmd_type = ADD_STREAM;
576
577 DBG("Sending kconsumerd header");
578
579 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
580 if (ret < 0) {
581 perror("send kconsumerd header");
582 goto error;
583 }
584
585 DBG("Sending metadata stream fd");
586
587 /* Send metadata stream fd first */
588 lkm.fd = session->metadata_stream_fd;
589 lkm.state = ACTIVE_FD;
590 lkm.max_sb_size = session->metadata->conf->subbuf_size;
591 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
592
593 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
594 if (ret < 0) {
595 perror("send kconsumerd fd");
596 goto error;
597 }
598
599 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
600 cds_list_for_each_entry(stream, &chan->stream_list.head, list) {
601 lkm.fd = stream->fd;
602 lkm.state = stream->state;
603 lkm.max_sb_size = chan->channel->subbuf_size;
604 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
605
606 DBG("Sending fd %d to kconsumerd", lkm.fd);
607
608 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
609 if (ret < 0) {
610 perror("send kconsumerd fd");
611 goto error;
612 }
613 }
614 }
615
616 DBG("Kconsumerd fds sent");
617
618 return 0;
619
620 error:
621 return ret;
622 }
623
624 /*
625 * create_trace_dir
626 *
627 * Create the trace output directory.
628 */
629 static int create_trace_dir(struct ltt_kernel_session *session)
630 {
631 int ret;
632 struct ltt_kernel_channel *chan;
633
634 /* Create all channel directories */
635 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
636 DBG("Creating trace directory at %s", chan->pathname);
637 ret = mkdir(chan->pathname, S_IRWXU | S_IRWXG );
638 if (ret < 0) {
639 perror("mkdir trace path");
640 ret = -errno;
641 goto error;
642 }
643 }
644
645 return 0;
646
647 error:
648 return ret;
649 }
650
651 /*
652 * init_kernel_tracer
653 *
654 * Setup necessary data for kernel tracer action.
655 */
656 static void init_kernel_tracer(void)
657 {
658 /* Set the global kernel tracer fd */
659 kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
660 if (kernel_tracer_fd < 0) {
661 WARN("No kernel tracer available");
662 kernel_tracer_fd = 0;
663 }
664
665 DBG("Kernel tracer fd %d", kernel_tracer_fd);
666 }
667
668 /*
669 * process_client_msg
670 *
671 * Process the command requested by the lttng client within the command
672 * context structure. This function make sure that the return structure (llm)
673 * is set and ready for transmission before returning.
674 *
675 * Return any error encountered or 0 for success.
676 */
677 static int process_client_msg(struct command_ctx *cmd_ctx)
678 {
679 int ret;
680
681 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
682
683 /* Check command that needs a session */
684 switch (cmd_ctx->lsm->cmd_type) {
685 case LTTNG_CREATE_SESSION:
686 case LTTNG_LIST_SESSIONS:
687 case KERNEL_LIST_EVENTS:
688 case UST_LIST_APPS:
689 break;
690 default:
691 cmd_ctx->session = find_session_by_uuid(cmd_ctx->lsm->session_uuid);
692 if (cmd_ctx->session == NULL) {
693 ret = LTTCOMM_SELECT_SESS;
694 goto error;
695 }
696 break;
697 }
698
699 /* Check command for kernel tracing */
700 switch (cmd_ctx->lsm->cmd_type) {
701 case KERNEL_CREATE_SESSION:
702 case KERNEL_CREATE_CHANNEL:
703 case KERNEL_CREATE_STREAM:
704 case KERNEL_DISABLE_EVENT:
705 case KERNEL_ENABLE_EVENT:
706 case KERNEL_LIST_EVENTS:
707 case KERNEL_OPEN_METADATA:
708 case KERNEL_START_TRACE:
709 case KERNEL_STOP_TRACE:
710 /* Kernel tracer check */
711 if (kernel_tracer_fd == 0) {
712 init_kernel_tracer();
713 if (kernel_tracer_fd == 0) {
714 ret = LTTCOMM_KERN_NA;
715 goto error;
716 }
717 }
718 break;
719 }
720
721 /* Connect to ust apps if available pid */
722 if (cmd_ctx->lsm->pid > 0) {
723 /* Connect to app using ustctl API */
724 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
725 if (cmd_ctx->ust_sock < 0) {
726 ret = LTTCOMM_NO_TRACEABLE;
727 goto error;
728 }
729 }
730
731 /* Process by command type */
732 switch (cmd_ctx->lsm->cmd_type) {
733 case KERNEL_CREATE_SESSION:
734 {
735 ret = setup_lttng_msg(cmd_ctx, 0);
736 if (ret < 0) {
737 goto setup_error;
738 }
739
740 ret = start_kconsumerd();
741 if (ret < 0) {
742 goto error;
743 }
744
745 DBG("Creating kernel session");
746
747 ret = kernel_create_session(cmd_ctx->session, kernel_tracer_fd);
748 if (ret < 0) {
749 ret = LTTCOMM_KERN_SESS_FAIL;
750 goto error;
751 }
752
753 ret = LTTCOMM_OK;
754 break;
755 }
756 case KERNEL_CREATE_CHANNEL:
757 {
758 ret = setup_lttng_msg(cmd_ctx, 0);
759 if (ret < 0) {
760 goto setup_error;
761 }
762
763 DBG("Creating kernel channel");
764
765 ret = kernel_create_channel(cmd_ctx->session->kernel_session);
766
767 if (ret < 0) {
768 ret = LTTCOMM_KERN_CHAN_FAIL;
769 goto error;
770 }
771
772 ret = LTTCOMM_OK;
773 break;
774 }
775 case KERNEL_ENABLE_EVENT:
776 {
777 /* Setup lttng message with no payload */
778 ret = setup_lttng_msg(cmd_ctx, 0);
779 if (ret < 0) {
780 goto setup_error;
781 }
782
783 DBG("Enabling kernel event %s", cmd_ctx->lsm->u.event.event_name);
784
785 ret = kernel_enable_event(cmd_ctx->session->kernel_session, cmd_ctx->lsm->u.event.event_name);
786 if (ret < 0) {
787 ret = LTTCOMM_KERN_ENABLE_FAIL;
788 goto error;
789 }
790
791 ret = LTTCOMM_OK;
792 break;
793 }
794 case KERNEL_ENABLE_ALL_EVENT:
795 {
796 int pos, size;
797 char *event_list, *event, *ptr;
798
799 /* Setup lttng message with no payload */
800 ret = setup_lttng_msg(cmd_ctx, 0);
801 if (ret < 0) {
802 goto setup_error;
803 }
804
805 DBG("Enabling all kernel event");
806
807 size = kernel_list_events(kernel_tracer_fd, &event_list);
808 if (size < 0) {
809 ret = LTTCOMM_KERN_LIST_FAIL;
810 goto error;
811 }
812
813 ptr = event_list;
814 while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
815 /* Enable each single event */
816 ret = kernel_enable_event(cmd_ctx->session->kernel_session, event);
817 if (ret < 0) {
818 ret = LTTCOMM_KERN_ENABLE_FAIL;
819 goto error;
820 }
821 /* Move pointer to the next line */
822 ptr += pos + 1;
823 free(event);
824 }
825
826 free(event_list);
827
828 ret = LTTCOMM_OK;
829 break;
830 }
831 case KERNEL_LIST_EVENTS:
832 {
833 char *event_list;
834 ssize_t size;
835
836 size = kernel_list_events(kernel_tracer_fd, &event_list);
837 if (size < 0) {
838 ret = LTTCOMM_KERN_LIST_FAIL;
839 goto error;
840 }
841
842 /*
843 * Setup lttng message with payload size set to the event list size in
844 * bytes and then copy list into the llm payload.
845 */
846 ret = setup_lttng_msg(cmd_ctx, size);
847 if (ret < 0) {
848 goto setup_error;
849 }
850
851 /* Copy event list into message payload */
852 memcpy(cmd_ctx->llm->payload, event_list, size);
853
854 free(event_list);
855
856 ret = LTTCOMM_OK;
857 break;
858 }
859 case KERNEL_OPEN_METADATA:
860 {
861 /* Setup lttng message with no payload */
862 ret = setup_lttng_msg(cmd_ctx, 0);
863 if (ret < 0) {
864 goto setup_error;
865 }
866
867 DBG("Open kernel metadata");
868
869 ret = kernel_open_metadata(cmd_ctx->session->kernel_session);
870 if (ret < 0) {
871 ret = LTTCOMM_KERN_META_FAIL;
872 goto error;
873 }
874
875 ret = LTTCOMM_OK;
876 break;
877 }
878 case KERNEL_CREATE_STREAM:
879 {
880 struct ltt_kernel_channel *chan;
881 /* Setup lttng message with no payload */
882 ret = setup_lttng_msg(cmd_ctx, 0);
883 if (ret < 0) {
884 goto setup_error;
885 }
886
887 DBG("Creating kernel stream");
888
889 ret = kernel_create_metadata_stream(cmd_ctx->session->kernel_session);
890 if (ret < 0) {
891 ERR("Kernel create metadata stream failed");
892 ret = LTTCOMM_KERN_STREAM_FAIL;
893 goto error;
894 }
895
896 /* For each channel */
897 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
898 ret = kernel_create_channel_stream(chan);
899 if (ret < 0) {
900 ERR("Kernel create channel stream failed");
901 ret = LTTCOMM_KERN_STREAM_FAIL;
902 goto error;
903 }
904 /* Update the stream global counter */
905 cmd_ctx->session->kernel_session->stream_count_global += ret;
906 }
907
908 ret = LTTCOMM_OK;
909 break;
910 }
911 case KERNEL_START_TRACE:
912 {
913 /* Setup lttng message with no payload */
914 ret = setup_lttng_msg(cmd_ctx, 0);
915 if (ret < 0) {
916 goto setup_error;
917 }
918
919 DBG("Start kernel tracing");
920
921 ret = create_trace_dir(cmd_ctx->session->kernel_session);
922 if (ret < 0) {
923 if (ret == -EEXIST) {
924 ret = LTTCOMM_KERN_DIR_EXIST;
925 } else {
926 ret = LTTCOMM_KERN_DIR_FAIL;
927 goto error;
928 }
929 }
930
931 ret = kernel_start_session(cmd_ctx->session->kernel_session);
932 if (ret < 0) {
933 ERR("Kernel start session failed");
934 ret = LTTCOMM_KERN_START_FAIL;
935 goto error;
936 }
937
938 ret = send_kconsumerd_fds(kconsumerd_cmd_sock, cmd_ctx->session->kernel_session);
939 if (ret < 0) {
940 ERR("Send kconsumerd fds failed");
941 ret = LTTCOMM_KERN_CONSUMER_FAIL;
942 goto error;
943 }
944
945 ret = LTTCOMM_OK;
946 break;
947 }
948 case KERNEL_STOP_TRACE:
949 {
950 /* Setup lttng message with no payload */
951 ret = setup_lttng_msg(cmd_ctx, 0);
952 if (ret < 0) {
953 goto setup_error;
954 }
955
956 if (cmd_ctx->session->kernel_session == NULL) {
957 ret = LTTCOMM_KERN_NO_SESSION;
958 goto error;
959 }
960
961 DBG("Stop kernel tracing");
962
963 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
964 if (ret < 0) {
965 ERR("Kernel stop session failed");
966 ret = LTTCOMM_KERN_STOP_FAIL;
967 goto error;
968 }
969
970 /* Clean kernel session teardown */
971 teardown_kernel_session(cmd_ctx->session);
972
973 ret = LTTCOMM_OK;
974 break;
975 }
976 case LTTNG_CREATE_SESSION:
977 {
978 /* Setup lttng message with no payload */
979 ret = setup_lttng_msg(cmd_ctx, 0);
980 if (ret < 0) {
981 goto setup_error;
982 }
983
984 ret = create_session(cmd_ctx->lsm->session_name, &cmd_ctx->llm->session_uuid);
985 if (ret < 0) {
986 if (ret == -1) {
987 ret = LTTCOMM_EXIST_SESS;
988 } else {
989 ret = LTTCOMM_FATAL;
990 }
991 goto error;
992 }
993
994 ret = LTTCOMM_OK;
995 break;
996 }
997 case LTTNG_DESTROY_SESSION:
998 {
999 /* Setup lttng message with no payload */
1000 ret = setup_lttng_msg(cmd_ctx, 0);
1001 if (ret < 0) {
1002 goto setup_error;
1003 }
1004
1005 ret = destroy_session(&cmd_ctx->lsm->session_uuid);
1006 if (ret < 0) {
1007 ret = LTTCOMM_NO_SESS;
1008 goto error;
1009 }
1010
1011 ret = LTTCOMM_OK;
1012 break;
1013 }
1014 case LTTNG_LIST_TRACES:
1015 {
1016 unsigned int trace_count;
1017
1018 trace_count = get_trace_count_per_session(cmd_ctx->session);
1019 if (trace_count == 0) {
1020 ret = LTTCOMM_NO_TRACE;
1021 goto error;
1022 }
1023
1024 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
1025 if (ret < 0) {
1026 goto setup_error;
1027 }
1028
1029 get_traces_per_session(cmd_ctx->session,
1030 (struct lttng_trace *)(cmd_ctx->llm->payload));
1031
1032 ret = LTTCOMM_OK;
1033 break;
1034 }
1035 case UST_CREATE_TRACE:
1036 {
1037 /* Setup lttng message with no payload */
1038 ret = setup_lttng_msg(cmd_ctx, 0);
1039 if (ret < 0) {
1040 goto setup_error;
1041 }
1042
1043 ret = ust_create_trace(cmd_ctx);
1044 if (ret < 0) {
1045 goto setup_error;
1046 }
1047 break;
1048 }
1049 case UST_LIST_APPS:
1050 {
1051 unsigned int app_count;
1052
1053 app_count = get_app_count();
1054 DBG("Traceable application count : %d", app_count);
1055 if (app_count == 0) {
1056 ret = LTTCOMM_NO_APPS;
1057 goto error;
1058 }
1059
1060 ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
1061 if (ret < 0) {
1062 goto setup_error;
1063 }
1064
1065 get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
1066
1067 ret = LTTCOMM_OK;
1068 break;
1069 }
1070 case UST_START_TRACE:
1071 {
1072 /* Setup lttng message with no payload */
1073 ret = setup_lttng_msg(cmd_ctx, 0);
1074 if (ret < 0) {
1075 goto setup_error;
1076 }
1077
1078 ret = ust_start_trace(cmd_ctx);
1079 if (ret < 0) {
1080 goto setup_error;
1081 }
1082 break;
1083 }
1084 case UST_STOP_TRACE:
1085 {
1086 /* Setup lttng message with no payload */
1087 ret = setup_lttng_msg(cmd_ctx, 0);
1088 if (ret < 0) {
1089 goto setup_error;
1090 }
1091
1092 ret = ust_stop_trace(cmd_ctx);
1093 if (ret < 0) {
1094 goto setup_error;
1095 }
1096 break;
1097 }
1098 case LTTNG_LIST_SESSIONS:
1099 {
1100 unsigned int session_count;
1101
1102 session_count = get_session_count();
1103 if (session_count == 0) {
1104 ret = LTTCOMM_NO_SESS;
1105 goto error;
1106 }
1107
1108 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * session_count);
1109 if (ret < 0) {
1110 goto setup_error;
1111 }
1112
1113 get_lttng_session((struct lttng_session *)(cmd_ctx->llm->payload));
1114
1115 ret = LTTCOMM_OK;
1116 break;
1117 }
1118 default:
1119 /* Undefined command */
1120 ret = setup_lttng_msg(cmd_ctx, 0);
1121 if (ret < 0) {
1122 goto setup_error;
1123 }
1124
1125 ret = LTTCOMM_UND;
1126 break;
1127 }
1128
1129 /* Set return code */
1130 cmd_ctx->llm->ret_code = ret;
1131
1132 return ret;
1133
1134 error:
1135 if (cmd_ctx->llm == NULL) {
1136 DBG("Missing llm structure. Allocating one.");
1137 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
1138 goto setup_error;
1139 }
1140 }
1141 /* Notify client of error */
1142 cmd_ctx->llm->ret_code = ret;
1143
1144 setup_error:
1145 return ret;
1146 }
1147
1148 /*
1149 * thread_manage_clients
1150 *
1151 * This thread manage all clients request using the unix
1152 * client socket for communication.
1153 */
1154 static void *thread_manage_clients(void *data)
1155 {
1156 int sock, ret;
1157 struct command_ctx *cmd_ctx;
1158
1159 DBG("[thread] Manage client started");
1160
1161 ret = lttcomm_listen_unix_sock(client_sock);
1162 if (ret < 0) {
1163 goto error;
1164 }
1165
1166 /* Notify parent pid that we are ready
1167 * to accept command for client side.
1168 */
1169 if (opt_sig_parent) {
1170 kill(ppid, SIGCHLD);
1171 }
1172
1173 while (1) {
1174 /* Blocking call, waiting for transmission */
1175 DBG("Accepting client command ...");
1176 sock = lttcomm_accept_unix_sock(client_sock);
1177 if (sock < 0) {
1178 goto error;
1179 }
1180
1181 /* Allocate context command to process the client request */
1182 cmd_ctx = malloc(sizeof(struct command_ctx));
1183
1184 /* Allocate data buffer for reception */
1185 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
1186 cmd_ctx->llm = NULL;
1187 cmd_ctx->session = NULL;
1188
1189 /*
1190 * Data is received from the lttng client. The struct
1191 * lttcomm_session_msg (lsm) contains the command and data request of
1192 * the client.
1193 */
1194 DBG("Receiving data from client ...");
1195 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
1196 if (ret <= 0) {
1197 continue;
1198 }
1199
1200 /*
1201 * This function dispatch the work to the kernel or userspace tracer
1202 * libs and fill the lttcomm_lttng_msg data structure of all the needed
1203 * informations for the client. The command context struct contains
1204 * everything this function may needs.
1205 */
1206 ret = process_client_msg(cmd_ctx);
1207 if (ret < 0) {
1208 /* TODO: Inform client somehow of the fatal error. At this point,
1209 * ret < 0 means that a malloc failed (ENOMEM). */
1210 /* Error detected but still accept command */
1211 clean_command_ctx(cmd_ctx);
1212 continue;
1213 }
1214
1215 DBG("Sending response (size: %d, retcode: %d)",
1216 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
1217 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
1218 if (ret < 0) {
1219 ERR("Failed to send data back to client");
1220 }
1221
1222 clean_command_ctx(cmd_ctx);
1223
1224 /* End of transmission */
1225 close(sock);
1226 }
1227
1228 error:
1229 return NULL;
1230 }
1231
1232
1233 /*
1234 * usage function on stderr
1235 */
1236 static void usage(void)
1237 {
1238 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
1239 fprintf(stderr, " -h, --help Display this usage.\n");
1240 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
1241 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
1242 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
1243 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
1244 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
1245 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
1246 fprintf(stderr, " -V, --version Show version number.\n");
1247 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
1248 fprintf(stderr, " -q, --quiet No output at all.\n");
1249 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
1250 }
1251
1252 /*
1253 * daemon argument parsing
1254 */
1255 static int parse_args(int argc, char **argv)
1256 {
1257 int c;
1258
1259 static struct option long_options[] = {
1260 { "client-sock", 1, 0, 'c' },
1261 { "apps-sock", 1, 0, 'a' },
1262 { "kconsumerd-cmd-sock", 1, 0, 0 },
1263 { "kconsumerd-err-sock", 1, 0, 0 },
1264 { "daemonize", 0, 0, 'd' },
1265 { "sig-parent", 0, 0, 'S' },
1266 { "help", 0, 0, 'h' },
1267 { "group", 1, 0, 'g' },
1268 { "version", 0, 0, 'V' },
1269 { "quiet", 0, 0, 'q' },
1270 { "verbose", 0, 0, 'v' },
1271 { NULL, 0, 0, 0 }
1272 };
1273
1274 while (1) {
1275 int option_index = 0;
1276 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
1277 if (c == -1) {
1278 break;
1279 }
1280
1281 switch (c) {
1282 case 0:
1283 fprintf(stderr, "option %s", long_options[option_index].name);
1284 if (optarg) {
1285 fprintf(stderr, " with arg %s\n", optarg);
1286 }
1287 break;
1288 case 'c':
1289 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
1290 break;
1291 case 'a':
1292 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
1293 break;
1294 case 'd':
1295 opt_daemon = 1;
1296 break;
1297 case 'g':
1298 opt_tracing_group = strdup(optarg);
1299 break;
1300 case 'h':
1301 usage();
1302 exit(EXIT_FAILURE);
1303 case 'V':
1304 fprintf(stdout, "%s\n", VERSION);
1305 exit(EXIT_SUCCESS);
1306 case 'S':
1307 opt_sig_parent = 1;
1308 break;
1309 case 'E':
1310 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
1311 break;
1312 case 'C':
1313 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
1314 break;
1315 case 'q':
1316 opt_quiet = 1;
1317 break;
1318 case 'v':
1319 opt_verbose = 1;
1320 break;
1321 default:
1322 /* Unknown option or other error.
1323 * Error is printed by getopt, just return */
1324 return -1;
1325 }
1326 }
1327
1328 return 0;
1329 }
1330
1331 /*
1332 * init_daemon_socket
1333 *
1334 * Creates the two needed socket by the daemon.
1335 * apps_sock - The communication socket for all UST apps.
1336 * client_sock - The communication of the cli tool (lttng).
1337 */
1338 static int init_daemon_socket()
1339 {
1340 int ret = 0;
1341 mode_t old_umask;
1342
1343 old_umask = umask(0);
1344
1345 /* Create client tool unix socket */
1346 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
1347 if (client_sock < 0) {
1348 ERR("Create unix sock failed: %s", client_unix_sock_path);
1349 ret = -1;
1350 goto end;
1351 }
1352
1353 /* File permission MUST be 660 */
1354 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
1355 if (ret < 0) {
1356 ERR("Set file permissions failed: %s", client_unix_sock_path);
1357 perror("chmod");
1358 goto end;
1359 }
1360
1361 /* Create the application unix socket */
1362 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
1363 if (apps_sock < 0) {
1364 ERR("Create unix sock failed: %s", apps_unix_sock_path);
1365 ret = -1;
1366 goto end;
1367 }
1368
1369 /* File permission MUST be 666 */
1370 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
1371 if (ret < 0) {
1372 ERR("Set file permissions failed: %s", apps_unix_sock_path);
1373 perror("chmod");
1374 goto end;
1375 }
1376
1377 end:
1378 umask(old_umask);
1379 return ret;
1380 }
1381
1382 /*
1383 * check_existing_daemon
1384 *
1385 * Check if the global socket is available.
1386 * If yes, error is returned.
1387 */
1388 static int check_existing_daemon()
1389 {
1390 int ret;
1391
1392 ret = access(client_unix_sock_path, F_OK);
1393 if (ret == 0) {
1394 ret = access(apps_unix_sock_path, F_OK);
1395 }
1396
1397 return ret;
1398 }
1399
1400 /*
1401 * get_home_dir
1402 *
1403 * Return pointer to home directory path using
1404 * the env variable HOME.
1405 *
1406 * Default : /tmp
1407 */
1408 static const char *get_home_dir(void)
1409 {
1410 const char *home_path;
1411
1412 if ((home_path = (const char *) getenv("HOME")) == NULL) {
1413 home_path = default_home_dir;
1414 }
1415
1416 return home_path;
1417 }
1418
1419 /*
1420 * set_permissions
1421 *
1422 * Set the tracing group gid onto the client socket.
1423 *
1424 * Race window between mkdir and chown is OK because we are going from
1425 * less permissive (root.root) to more permissive (root.tracing).
1426 */
1427 static int set_permissions(void)
1428 {
1429 int ret;
1430 struct group *grp;
1431
1432 /* Decide which group name to use */
1433 (opt_tracing_group != NULL) ?
1434 (grp = getgrnam(opt_tracing_group)) :
1435 (grp = getgrnam(default_tracing_group));
1436
1437 if (grp == NULL) {
1438 ERR("Missing tracing group. Aborting execution.\n");
1439 ret = -1;
1440 goto end;
1441 }
1442
1443 /* Set lttng run dir */
1444 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
1445 if (ret < 0) {
1446 ERR("Unable to set group on " LTTNG_RUNDIR);
1447 perror("chown");
1448 }
1449
1450 /* lttng client socket path */
1451 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
1452 if (ret < 0) {
1453 ERR("Unable to set group on %s", client_unix_sock_path);
1454 perror("chown");
1455 }
1456
1457 /* kconsumerd error socket path */
1458 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
1459 if (ret < 0) {
1460 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
1461 perror("chown");
1462 }
1463
1464 DBG("All permissions are set");
1465
1466 end:
1467 return ret;
1468 }
1469
1470 /*
1471 * create_lttng_rundir
1472 *
1473 * Create the lttng run directory needed for all
1474 * global sockets and pipe.
1475 */
1476 static int create_lttng_rundir(void)
1477 {
1478 int ret;
1479
1480 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
1481 if (ret < 0) {
1482 if (errno != EEXIST) {
1483 ERR("Unable to create " LTTNG_RUNDIR);
1484 goto error;
1485 } else {
1486 ret = 0;
1487 }
1488 }
1489
1490 error:
1491 return ret;
1492 }
1493
1494 /*
1495 * set_kconsumerd_sockets
1496 *
1497 * Setup sockets and directory needed by the kconsumerd
1498 * communication with the session daemon.
1499 */
1500 static int set_kconsumerd_sockets(void)
1501 {
1502 int ret;
1503
1504 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
1505 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
1506 }
1507
1508 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
1509 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
1510 }
1511
1512 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
1513 if (ret < 0) {
1514 ERR("Failed to create " KCONSUMERD_PATH);
1515 goto error;
1516 }
1517
1518 /* Create the kconsumerd error unix socket */
1519 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
1520 if (kconsumerd_err_sock < 0) {
1521 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
1522 ret = -1;
1523 goto error;
1524 }
1525
1526 /* File permission MUST be 660 */
1527 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
1528 if (ret < 0) {
1529 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
1530 perror("chmod");
1531 goto error;
1532 }
1533
1534 error:
1535 return ret;
1536 }
1537
1538 /*
1539 * sighandler
1540 *
1541 * Signal handler for the daemon
1542 */
1543 static void sighandler(int sig)
1544 {
1545 switch (sig) {
1546 case SIGPIPE:
1547 DBG("SIGPIPE catched");
1548 return;
1549 case SIGINT:
1550 DBG("SIGINT catched");
1551 cleanup();
1552 break;
1553 case SIGTERM:
1554 DBG("SIGTERM catched");
1555 cleanup();
1556 break;
1557 default:
1558 break;
1559 }
1560
1561 exit(EXIT_SUCCESS);
1562 }
1563
1564 /*
1565 * set_signal_handler
1566 *
1567 * Setup signal handler for :
1568 * SIGINT, SIGTERM, SIGPIPE
1569 */
1570 static int set_signal_handler(void)
1571 {
1572 int ret = 0;
1573 struct sigaction sa;
1574 sigset_t sigset;
1575
1576 if ((ret = sigemptyset(&sigset)) < 0) {
1577 perror("sigemptyset");
1578 return ret;
1579 }
1580
1581 sa.sa_handler = sighandler;
1582 sa.sa_mask = sigset;
1583 sa.sa_flags = 0;
1584 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1585 perror("sigaction");
1586 return ret;
1587 }
1588
1589 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1590 perror("sigaction");
1591 return ret;
1592 }
1593
1594 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
1595 perror("sigaction");
1596 return ret;
1597 }
1598
1599 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
1600
1601 return ret;
1602 }
1603
1604 /*
1605 * main
1606 */
1607 int main(int argc, char **argv)
1608 {
1609 int ret = 0;
1610 void *status;
1611
1612 /* Parse arguments */
1613 progname = argv[0];
1614 if ((ret = parse_args(argc, argv) < 0)) {
1615 goto error;
1616 }
1617
1618 /* Daemonize */
1619 if (opt_daemon) {
1620 ret = daemon(0, 0);
1621 if (ret < 0) {
1622 perror("daemon");
1623 goto error;
1624 }
1625 }
1626
1627 /* Check if daemon is UID = 0 */
1628 is_root = !getuid();
1629
1630 /* Set all sockets path */
1631 if (is_root) {
1632 ret = create_lttng_rundir();
1633 if (ret < 0) {
1634 goto error;
1635 }
1636
1637 if (strlen(apps_unix_sock_path) == 0) {
1638 snprintf(apps_unix_sock_path, PATH_MAX,
1639 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
1640 }
1641
1642 if (strlen(client_unix_sock_path) == 0) {
1643 snprintf(client_unix_sock_path, PATH_MAX,
1644 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
1645 }
1646
1647 ret = set_kconsumerd_sockets();
1648 if (ret < 0) {
1649 goto error;
1650 }
1651
1652 /* Setup kernel tracer */
1653 init_kernel_tracer();
1654 } else {
1655 if (strlen(apps_unix_sock_path) == 0) {
1656 snprintf(apps_unix_sock_path, PATH_MAX,
1657 DEFAULT_HOME_APPS_UNIX_SOCK, get_home_dir());
1658 }
1659
1660 /* Set the cli tool unix socket path */
1661 if (strlen(client_unix_sock_path) == 0) {
1662 snprintf(client_unix_sock_path, PATH_MAX,
1663 DEFAULT_HOME_CLIENT_UNIX_SOCK, get_home_dir());
1664 }
1665 }
1666
1667 DBG("Client socket path %s", client_unix_sock_path);
1668 DBG("Application socket path %s", apps_unix_sock_path);
1669
1670 /* See if daemon already exist. If any of the two
1671 * socket needed by the daemon are present, this test fails
1672 */
1673 if ((ret = check_existing_daemon()) == 0) {
1674 ERR("Already running daemon.\n");
1675 /* We do not goto error because we must not
1676 * cleanup() because a daemon is already running.
1677 */
1678 exit(EXIT_FAILURE);
1679 }
1680
1681 if (set_signal_handler() < 0) {
1682 goto error;
1683 }
1684
1685 /* Setup the needed unix socket */
1686 if (init_daemon_socket() < 0) {
1687 goto error;
1688 }
1689
1690 /* Set credentials to socket */
1691 if (is_root && (set_permissions() < 0)) {
1692 goto error;
1693 }
1694
1695 /* Get parent pid if -S, --sig-parent is specified. */
1696 if (opt_sig_parent) {
1697 ppid = getppid();
1698 }
1699
1700 while (1) {
1701 /* Create thread to manage the client socket */
1702 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
1703 if (ret != 0) {
1704 perror("pthread_create");
1705 goto error;
1706 }
1707
1708 /* Create thread to manage application socket */
1709 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
1710 if (ret != 0) {
1711 perror("pthread_create");
1712 goto error;
1713 }
1714
1715 ret = pthread_join(client_thread, &status);
1716 if (ret != 0) {
1717 perror("pthread_join");
1718 goto error;
1719 }
1720 }
1721
1722 cleanup();
1723 exit(EXIT_SUCCESS);
1724
1725 error:
1726 cleanup();
1727 exit(EXIT_FAILURE);
1728 }
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