Add enable kernel event using the enable ioctl
[lttng-tools.git] / ltt-sessiond / main.c
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CommitLineData
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 <sys/time.h>
36#include <sys/resource.h>
37#include <unistd.h>
38
39#include <urcu/list.h> /* URCU list library (-lurcu) */
40#include <lttng/lttng.h>
41
42#include "liblttsessiondcomm.h"
43#include "ltt-sessiond.h"
44#include "lttngerr.h"
45#include "kernel-ctl.h"
46#include "ust-ctl.h"
47#include "session.h"
48#include "traceable-app.h"
49#include "lttng-kconsumerd.h"
50#include "libustctl.h"
51
52/*
53 * TODO:
54 * teardown: signal SIGTERM handler -> write into pipe. Threads waits
55 * with epoll on pipe and on other pipes/sockets for commands. Main
56 * simply waits on pthread join.
57 */
58
59/* Const values */
60const char default_home_dir[] = DEFAULT_HOME_DIR;
61const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
62const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
63const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
64
65/* Variables */
66int opt_verbose; /* Not static for lttngerr.h */
67int opt_quiet; /* Not static for lttngerr.h */
68const char *progname;
69const char *opt_tracing_group;
70static int opt_sig_parent;
71static int opt_daemon;
72static int is_root; /* Set to 1 if the daemon is running as root */
73static pid_t ppid; /* Parent PID for --sig-parent option */
74static pid_t kconsumerd_pid;
75
76static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
77static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
78static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
79static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
80
81/* Sockets and FDs */
82static int client_sock;
83static int apps_sock;
84static int kconsumerd_err_sock;
85static int kconsumerd_cmd_sock;
86static int kernel_tracer_fd;
87
88/* Pthread, Mutexes and Semaphores */
89static pthread_t kconsumerd_thread;
90static pthread_t apps_thread;
91static pthread_t client_thread;
92static sem_t kconsumerd_sem;
93
94static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
95
96/*
97 * teardown_kernel_session
98 *
99 * Complete teardown of a kernel session. This free all data structure
100 * related to a kernel session and update counter.
101 */
102static void teardown_kernel_session(struct ltt_session *session)
103{
104 if (session->kernel_session != NULL) {
105 DBG("Tearing down kernel session");
106 trace_destroy_kernel_session(session->kernel_session);
107 /* Extra precaution */
108 session->kernel_session = NULL;
109 /* Decrement session count */
110 session->kern_session_count--;
111 }
112}
113
114/*
115 * cleanup
116 *
117 * Cleanup the daemon on exit
118 */
119static void cleanup()
120{
121 int ret;
122 char *cmd;
123 struct ltt_session *sess;
124
125 DBG("Cleaning up");
126
127 /* <fun> */
128 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
129 MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0);
130 /* </fun> */
131
132 /* Stopping all threads */
133 DBG("Terminating all threads");
134 pthread_cancel(client_thread);
135 pthread_cancel(apps_thread);
136 if (kconsumerd_pid != 0) {
137 pthread_cancel(kconsumerd_thread);
138 }
139
140 DBG("Unlinking all unix socket");
141 unlink(client_unix_sock_path);
142 unlink(apps_unix_sock_path);
143 unlink(kconsumerd_err_unix_sock_path);
144
145 DBG("Removing %s directory", LTTNG_RUNDIR);
146 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
147 if (ret < 0) {
148 ERR("asprintf failed. Something is really wrong!");
149 }
150
151 /* Remove lttng run directory */
152 ret = system(cmd);
153 if (ret < 0) {
154 ERR("Unable to clean " LTTNG_RUNDIR);
155 }
156
157 DBG("Cleaning up all session");
158 /* Cleanup ALL session */
159 cds_list_for_each_entry(sess, &ltt_session_list.head, list) {
160 teardown_kernel_session(sess);
161 // TODO complete session cleanup (including UST)
162 }
163
164 DBG("Closing kernel fd");
165 close(kernel_tracer_fd);
166}
167
168/*
169 * send_unix_sock
170 *
171 * Send data on a unix socket using the liblttsessiondcomm API.
172 *
173 * Return lttcomm error code.
174 */
175static int send_unix_sock(int sock, void *buf, size_t len)
176{
177 /* Check valid length */
178 if (len <= 0) {
179 return -1;
180 }
181
182 return lttcomm_send_unix_sock(sock, buf, len);
183}
184
185/*
186 * clean_command_ctx
187 *
188 * Free memory of a command context structure.
189 */
190static void clean_command_ctx(struct command_ctx *cmd_ctx)
191{
192 DBG("Clean command context structure %p", cmd_ctx);
193 if (cmd_ctx) {
194 if (cmd_ctx->llm) {
195 free(cmd_ctx->llm);
196 }
197 if (cmd_ctx->lsm) {
198 free(cmd_ctx->lsm);
199 }
200 free(cmd_ctx);
201 cmd_ctx = NULL;
202 }
203}
204
205/*
206 * send_kconsumerd_fds
207 *
208 * Send all stream fds of the kernel session to the consumer.
209 */
210static int send_kconsumerd_fds(int sock, struct ltt_kernel_session *session)
211{
212 int ret;
213 size_t nb_fd;
214 struct ltt_kernel_stream *stream;
215 struct ltt_kernel_channel *chan;
216 struct lttcomm_kconsumerd_header lkh;
217 struct lttcomm_kconsumerd_msg lkm;
218
219 nb_fd = session->stream_count_global;
220
221 /* Setup header */
222 lkh.payload_size = (nb_fd + 1) * sizeof(struct lttcomm_kconsumerd_msg);
223 lkh.cmd_type = ADD_STREAM;
224
225 DBG("Sending kconsumerd header");
226
227 ret = lttcomm_send_unix_sock(sock, &lkh, sizeof(struct lttcomm_kconsumerd_header));
228 if (ret < 0) {
229 perror("send kconsumerd header");
230 goto error;
231 }
232
233 DBG("Sending metadata stream fd");
234
235 /* Send metadata stream fd first */
236 lkm.fd = session->metadata_stream_fd;
237 lkm.state = ACTIVE_FD;
238 lkm.max_sb_size = session->metadata->conf->attr.subbuf_size;
239 strncpy(lkm.path_name, session->metadata->pathname, PATH_MAX);
240
241 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
242 if (ret < 0) {
243 perror("send kconsumerd fd");
244 goto error;
245 }
246
247 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
248 cds_list_for_each_entry(stream, &chan->stream_list.head, list) {
249 lkm.fd = stream->fd;
250 lkm.state = stream->state;
251 lkm.max_sb_size = chan->channel->attr.subbuf_size;
252 strncpy(lkm.path_name, stream->pathname, PATH_MAX);
253
254 DBG("Sending fd %d to kconsumerd", lkm.fd);
255
256 ret = lttcomm_send_fds_unix_sock(sock, &lkm, &lkm.fd, 1, sizeof(lkm));
257 if (ret < 0) {
258 perror("send kconsumerd fd");
259 goto error;
260 }
261 }
262 }
263
264 DBG("Kconsumerd fds sent");
265
266 return 0;
267
268error:
269 return ret;
270}
271
272/*
273 * create_trace_dir
274 *
275 * Create the trace output directory.
276 */
277static int create_trace_dir(struct ltt_kernel_session *session)
278{
279 int ret;
280 struct ltt_kernel_channel *chan;
281
282 /* Create all channel directories */
283 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
284 DBG("Creating trace directory at %s", chan->pathname);
285 // TODO: recursive create dir
286 ret = mkdir(chan->pathname, S_IRWXU | S_IRWXG );
287 if (ret < 0) {
288 if (ret != EEXIST) {
289 perror("mkdir trace path");
290 ret = -errno;
291 goto error;
292 }
293 }
294 }
295
296 return 0;
297
298error:
299 return ret;
300}
301
302/*
303 * ust_connect_app
304 *
305 * Return a socket connected to the libust communication socket
306 * of the application identified by the pid.
307 *
308 * If the pid is not found in the traceable list,
309 * return -1 to indicate error.
310 */
311static int ust_connect_app(pid_t pid)
312{
313 int sock;
314 struct ltt_traceable_app *lta;
315
316 DBG("Connect to application pid %d", pid);
317
318 lta = find_app_by_pid(pid);
319 if (lta == NULL) {
320 /* App not found */
321 DBG("Application pid %d not found", pid);
322 return -1;
323 }
324
325 sock = ustctl_connect_pid(lta->pid);
326 if (sock < 0) {
327 ERR("Fail connecting to the PID %d", pid);
328 }
329
330 return sock;
331}
332
333/*
334 * notify_apps
335 *
336 * Notify apps by writing 42 to a named pipe using name.
337 * Every applications waiting for a ltt-sessiond will be notified
338 * and re-register automatically to the session daemon.
339 *
340 * Return open or write error value.
341 */
342static int notify_apps(const char *name)
343{
344 int fd;
345 int ret = -1;
346
347 DBG("Notify the global application pipe");
348
349 /* Try opening the global pipe */
350 fd = open(name, O_WRONLY);
351 if (fd < 0) {
352 goto error;
353 }
354
355 /* Notify by writing on the pipe */
356 ret = write(fd, "42", 2);
357 if (ret < 0) {
358 perror("write");
359 }
360
361error:
362 return ret;
363}
364
365/*
366 * setup_lttng_msg
367 *
368 * Setup the outgoing data buffer for the response (llm) by allocating the
369 * right amount of memory and copying the original information from the lsm
370 * structure.
371 *
372 * Return total size of the buffer pointed by buf.
373 */
374static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
375{
376 int ret, buf_size;
377
378 buf_size = size;
379
380 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
381 if (cmd_ctx->llm == NULL) {
382 perror("malloc");
383 ret = -ENOMEM;
384 goto error;
385 }
386
387 /* Copy common data */
388 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
389 cmd_ctx->llm->pid = cmd_ctx->lsm->pid;
390
391 cmd_ctx->llm->data_size = size;
392 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
393
394 return buf_size;
395
396error:
397 return ret;
398}
399
400/*
401 * thread_manage_kconsumerd
402 *
403 * This thread manage the kconsumerd error sent
404 * back to the session daemon.
405 */
406static void *thread_manage_kconsumerd(void *data)
407{
408 int sock, ret;
409 enum lttcomm_return_code code;
410
411 DBG("[thread] Manage kconsumerd started");
412
413 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
414 if (ret < 0) {
415 goto error;
416 }
417
418 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
419 if (sock < 0) {
420 goto error;
421 }
422
423 /* Getting status code from kconsumerd */
424 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
425 if (ret <= 0) {
426 goto error;
427 }
428
429 if (code == KCONSUMERD_COMMAND_SOCK_READY) {
430 kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
431 if (kconsumerd_cmd_sock < 0) {
432 sem_post(&kconsumerd_sem);
433 perror("kconsumerd connect");
434 goto error;
435 }
436 /* Signal condition to tell that the kconsumerd is ready */
437 sem_post(&kconsumerd_sem);
438 DBG("Kconsumerd command socket ready");
439 } else {
440 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
441 lttcomm_get_readable_code(-code));
442 goto error;
443 }
444
445 /* Wait for any kconsumerd error */
446 ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
447 if (ret <= 0) {
448 ERR("Kconsumerd closed the command socket");
449 goto error;
450 }
451
452 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
453
454error:
455 kconsumerd_pid = 0;
456 DBG("Kconsumerd thread dying");
457 return NULL;
458}
459
460/*
461 * thread_manage_apps
462 *
463 * This thread manage the application socket communication
464 */
465static void *thread_manage_apps(void *data)
466{
467 int sock, ret;
468
469 /* TODO: Something more elegant is needed but fine for now */
470 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
471 * for 32-bit vs 64-bit compat processes. */
472 /* replicate in ust with version number */
473 struct {
474 int reg; /* 1:register, 0:unregister */
475 pid_t pid;
476 uid_t uid;
477 } reg_msg;
478
479 DBG("[thread] Manage apps started");
480
481 ret = lttcomm_listen_unix_sock(apps_sock);
482 if (ret < 0) {
483 goto error;
484 }
485
486 /* Notify all applications to register */
487 notify_apps(default_global_apps_pipe);
488
489 while (1) {
490 DBG("Accepting application registration");
491 /* Blocking call, waiting for transmission */
492 sock = lttcomm_accept_unix_sock(apps_sock);
493 if (sock < 0) {
494 goto error;
495 }
496
497 /* Basic recv here to handle the very simple data
498 * that the libust send to register (reg_msg).
499 */
500 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
501 if (ret < 0) {
502 perror("recv");
503 continue;
504 }
505
506 /* Add application to the global traceable list */
507 if (reg_msg.reg == 1) {
508 /* Registering */
509 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
510 if (ret < 0) {
511 /* register_traceable_app only return an error with
512 * ENOMEM. At this point, we better stop everything.
513 */
514 goto error;
515 }
516 } else {
517 /* Unregistering */
518 unregister_traceable_app(reg_msg.pid);
519 }
520 }
521
522error:
523
524 return NULL;
525}
526
527/*
528 * spawn_kconsumerd_thread
529 *
530 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
531 * exec or it will fails.
532 */
533static int spawn_kconsumerd_thread(void)
534{
535 int ret;
536
537 /* Setup semaphore */
538 sem_init(&kconsumerd_sem, 0, 0);
539
540 ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
541 if (ret != 0) {
542 perror("pthread_create kconsumerd");
543 goto error;
544 }
545
546 /* Wait for the kconsumerd thread to be ready */
547 sem_wait(&kconsumerd_sem);
548
549 if (kconsumerd_pid == 0) {
550 ERR("Kconsumerd did not start");
551 goto error;
552 }
553
554 return 0;
555
556error:
557 ret = LTTCOMM_KERN_CONSUMER_FAIL;
558 return ret;
559}
560
561/*
562 * spawn_kconsumerd
563 *
564 * Fork and exec a kernel consumer daemon (kconsumerd).
565 *
566 * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel
567 * file descriptor using the libkernelctl or kernel-ctl functions. So, a
568 * kernel consumer MUST only be spawned before creating a kernel session.
569 *
570 * Return pid if successful else -1.
571 */
572static pid_t spawn_kconsumerd(void)
573{
574 int ret;
575 pid_t pid;
576
577 DBG("Spawning kconsumerd");
578
579 pid = fork();
580 if (pid == 0) {
581 /*
582 * Exec kconsumerd.
583 */
584 execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
585 if (errno != 0) {
586 perror("kernel start consumer exec");
587 }
588 exit(EXIT_FAILURE);
589 } else if (pid > 0) {
590 ret = pid;
591 goto error;
592 } else {
593 perror("kernel start consumer fork");
594 ret = -errno;
595 goto error;
596 }
597
598error:
599 return ret;
600}
601
602/*
603 * start_kconsumerd
604 *
605 * Spawn the kconsumerd daemon and session daemon thread.
606 */
607static int start_kconsumerd(void)
608{
609 int ret;
610
611 pthread_mutex_lock(&kconsumerd_pid_mutex);
612 if (kconsumerd_pid != 0) {
613 goto end;
614 }
615
616 ret = spawn_kconsumerd();
617 if (ret < 0) {
618 ERR("Spawning kconsumerd failed");
619 ret = LTTCOMM_KERN_CONSUMER_FAIL;
620 pthread_mutex_unlock(&kconsumerd_pid_mutex);
621 goto error;
622 }
623
624 /* Setting up the global kconsumerd_pid */
625 kconsumerd_pid = ret;
626 pthread_mutex_unlock(&kconsumerd_pid_mutex);
627
628 DBG("Kconsumerd pid %d", ret);
629
630 DBG("Spawning kconsumerd thread");
631 ret = spawn_kconsumerd_thread();
632 if (ret < 0) {
633 ERR("Fatal error spawning kconsumerd thread");
634 goto error;
635 }
636
637end:
638 pthread_mutex_unlock(&kconsumerd_pid_mutex);
639 return 0;
640
641error:
642 return ret;
643}
644
645/*
646 * init_kernel_tracer
647 *
648 * Setup necessary data for kernel tracer action.
649 */
650static void init_kernel_tracer(void)
651{
652 /* Set the global kernel tracer fd */
653 kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
654 if (kernel_tracer_fd < 0) {
655 WARN("No kernel tracer available");
656 kernel_tracer_fd = 0;
657 }
658
659 DBG("Kernel tracer fd %d", kernel_tracer_fd);
660}
661
662/*
663 * start_kernel_trace
664 *
665 * Start tracing by creating trace directory and sending FDs to the kernel
666 * consumer.
667 */
668static int start_kernel_trace(struct ltt_kernel_session *session)
669{
670 int ret;
671
672 /* Create trace directory */
673 ret = create_trace_dir(session);
674 if (ret < 0) {
675 if (ret == -EEXIST) {
676 ret = LTTCOMM_KERN_DIR_EXIST;
677 } else {
678 ret = LTTCOMM_KERN_DIR_FAIL;
679 goto error;
680 }
681 }
682
683 if (session->kconsumer_fds_sent == 0) {
684 ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
685 if (ret < 0) {
686 ERR("Send kconsumerd fds failed");
687 ret = LTTCOMM_KERN_CONSUMER_FAIL;
688 goto error;
689 }
690
691 session->kconsumer_fds_sent = 1;
692 }
693
694error:
695 return ret;
696}
697
698/*
699 * init_default_channel
700 *
701 * Allocate a channel structure and fill it.
702 */
703static struct lttng_channel *init_default_channel(void)
704{
705 struct lttng_channel *chan;
706
707 chan = malloc(sizeof(struct lttng_channel));
708 if (chan == NULL) {
709 perror("init channel malloc");
710 goto error;
711 }
712
713 if (snprintf(chan->name, NAME_MAX, DEFAULT_CHANNEL_NAME) < 0) {
714 perror("snprintf defautl channel name");
715 return NULL;
716 }
717
718 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
719 chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
720 chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
721 chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
722 chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
723
724error:
725 return chan;
726}
727
728/*
729 * create_kernel_session
730 *
731 * Create a kernel tracer session then create the default channel.
732 */
733static int create_kernel_session(struct ltt_session *session)
734{
735 int ret;
736 struct lttng_channel *chan;
737
738 DBG("Creating kernel session");
739
740 ret = kernel_create_session(session, kernel_tracer_fd);
741 if (ret < 0) {
742 ret = LTTCOMM_KERN_SESS_FAIL;
743 goto error;
744 }
745
746 chan = init_default_channel();
747 if (chan == NULL) {
748 ret = LTTCOMM_FATAL;
749 goto error;
750 }
751
752 DBG("Creating default kernel channel %s", DEFAULT_CHANNEL_NAME);
753
754 ret = kernel_create_channel(session->kernel_session, chan);
755 if (ret < 0) {
756 ret = LTTCOMM_KERN_CHAN_FAIL;
757 goto error;
758 }
759
760error:
761 return ret;
762}
763
764/*
765 * process_client_msg
766 *
767 * Process the command requested by the lttng client within the command
768 * context structure. This function make sure that the return structure (llm)
769 * is set and ready for transmission before returning.
770 *
771 * Return any error encountered or 0 for success.
772 */
773static int process_client_msg(struct command_ctx *cmd_ctx)
774{
775 int ret;
776
777 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
778
779 /* Listing commands don't need a session */
780 switch (cmd_ctx->lsm->cmd_type) {
781 case LTTNG_CREATE_SESSION:
782 case LTTNG_LIST_SESSIONS:
783 case LTTNG_LIST_EVENTS:
784 case LTTNG_KERNEL_LIST_EVENTS:
785 case LTTNG_LIST_TRACEABLE_APPS:
786 break;
787 default:
788 DBG("Getting session %s by name", cmd_ctx->lsm->session_name);
789 cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name);
790 if (cmd_ctx->session == NULL) {
791 /* If session name not found */
792 if (cmd_ctx->lsm->session_name != NULL) {
793 ret = LTTCOMM_SESS_NOT_FOUND;
794 } else { /* If no session name specified */
795 ret = LTTCOMM_SELECT_SESS;
796 }
797 goto error;
798 }
799 break;
800 }
801
802 /*
803 * Check kernel command for kernel session.
804 */
805 switch (cmd_ctx->lsm->cmd_type) {
806 case LTTNG_KERNEL_CREATE_CHANNEL:
807 case LTTNG_KERNEL_DISABLE_ALL_EVENT:
808 case LTTNG_KERNEL_DISABLE_CHANNEL:
809 case LTTNG_KERNEL_DISABLE_EVENT:
810 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
811 case LTTNG_KERNEL_ENABLE_CHANNEL:
812 case LTTNG_KERNEL_ENABLE_EVENT:
813 case LTTNG_KERNEL_LIST_EVENTS:
814 /* Kernel tracer check */
815 if (kernel_tracer_fd == 0) {
816 init_kernel_tracer();
817 if (kernel_tracer_fd == 0) {
818 ret = LTTCOMM_KERN_NA;
819 goto error;
820 }
821 }
822
823 /* Need a session for kernel command */
824 if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS &&
825 cmd_ctx->session->kernel_session == NULL) {
826
827 ret = create_kernel_session(cmd_ctx->session);
828 if (ret < 0) {
829 ret = LTTCOMM_KERN_SESS_FAIL;
830 goto error;
831 }
832
833 /* Start the kernel consumer daemon */
834 if (kconsumerd_pid == 0) {
835 ret = start_kconsumerd();
836 if (ret < 0) {
837 goto error;
838 }
839 }
840 }
841 }
842
843 /* Connect to ust apps if available pid */
844 if (cmd_ctx->lsm->pid > 0) {
845 /* Connect to app using ustctl API */
846 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
847 if (cmd_ctx->ust_sock < 0) {
848 ret = LTTCOMM_NO_TRACEABLE;
849 goto error;
850 }
851 }
852
853 /* Process by command type */
854 switch (cmd_ctx->lsm->cmd_type) {
855 case LTTNG_KERNEL_CREATE_CHANNEL:
856 {
857 /* Setup lttng message with no payload */
858 ret = setup_lttng_msg(cmd_ctx, 0);
859 if (ret < 0) {
860 goto setup_error;
861 }
862
863 /* Kernel tracer */
864 DBG("Creating kernel channel");
865
866 ret = kernel_create_channel(cmd_ctx->session->kernel_session,
867 &cmd_ctx->lsm->u.channel.chan);
868 if (ret < 0) {
869 ret = LTTCOMM_KERN_CHAN_FAIL;
870 goto error;
871 }
872
873 ret = LTTCOMM_OK;
874 break;
875 }
876 case LTTNG_KERNEL_DISABLE_EVENT:
877 {
878 struct ltt_kernel_channel *chan;
879 struct ltt_kernel_event *ev;
880
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 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.disable.channel_name,
888 cmd_ctx->session->kernel_session);
889 if (chan == NULL) {
890 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
891 goto error;
892 }
893
894 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.disable.name, chan);
895 if (ev != NULL) {
896 DBG("Disabling kernel event %s for channel %s.",
897 cmd_ctx->lsm->u.disable.name, cmd_ctx->lsm->u.disable.channel_name);
898 ret = kernel_disable_event(ev);
899 if (ret < 0) {
900 ret = LTTCOMM_KERN_ENABLE_FAIL;
901 goto error;
902 }
903 }
904
905 kernel_wait_quiescent(kernel_tracer_fd);
906 ret = LTTCOMM_OK;
907 break;
908 }
909 case LTTNG_KERNEL_ENABLE_EVENT:
910 {
911 struct ltt_kernel_channel *chan;
912 struct ltt_kernel_event *ev;
913
914 /* Setup lttng message with no payload */
915 ret = setup_lttng_msg(cmd_ctx, 0);
916 if (ret < 0) {
917 goto setup_error;
918 }
919
920 chan = get_kernel_channel_by_name(cmd_ctx->lsm->u.enable.channel_name,
921 cmd_ctx->session->kernel_session);
922 if (chan == NULL) {
923 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
924 goto error;
925 }
926
927 ev = get_kernel_event_by_name(cmd_ctx->lsm->u.enable.event.name, chan);
928 if (ev == NULL) {
929 DBG("Creating kernel event %s for channel %s.",
930 cmd_ctx->lsm->u.enable.event.name, cmd_ctx->lsm->u.enable.channel_name);
931 ret = kernel_create_event(&cmd_ctx->lsm->u.enable.event, chan);
932 } else {
933 DBG("Enabling kernel event %s for channel %s.",
934 cmd_ctx->lsm->u.enable.event.name, cmd_ctx->lsm->u.enable.channel_name);
935 ret = kernel_enable_event(ev);
936 }
937
938 if (ret < 0) {
939 ret = LTTCOMM_KERN_ENABLE_FAIL;
940 goto error;
941 }
942
943 kernel_wait_quiescent(kernel_tracer_fd);
944 ret = LTTCOMM_OK;
945 break;
946 }
947 case LTTNG_KERNEL_ENABLE_ALL_EVENT:
948 {
949 int pos, size, found;
950 char *event_list, *event, *ptr;
951 struct ltt_kernel_channel *chan;
952 struct lttng_event ev;
953
954 /* Setup lttng message with no payload */
955 ret = setup_lttng_msg(cmd_ctx, 0);
956 if (ret < 0) {
957 goto setup_error;
958 }
959
960 DBG("Enabling all kernel event");
961
962 size = kernel_list_events(kernel_tracer_fd, &event_list);
963 if (size < 0) {
964 ret = LTTCOMM_KERN_LIST_FAIL;
965 goto error;
966 }
967
968 /* Get channel by name and create event for that channel */
969 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
970 if (strcmp(cmd_ctx->lsm->u.enable.channel_name, chan->channel->name) == 0) {
971 found = 1;
972 break;
973 }
974 }
975
976 if (!found) {
977 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
978 goto error;
979 }
980
981 ptr = event_list;
982 while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
983 strncpy(ev.name, event, LTTNG_SYM_NAME_LEN);
984 /* Default event type for enable all */
985 ev.type = LTTNG_EVENT_TRACEPOINTS;
986 /* Enable each single tracepoint event */
987 ret = kernel_create_event(&ev, chan);
988 if (ret < 0) {
989 ret = LTTCOMM_KERN_ENABLE_FAIL;
990 goto error;
991 }
992 /* Move pointer to the next line */
993 ptr += pos + 1;
994 free(event);
995 }
996
997 free(event_list);
998
999 /* Quiescent wait after event enable */
1000 kernel_wait_quiescent(kernel_tracer_fd);
1001 ret = LTTCOMM_OK;
1002 break;
1003 }
1004 case LTTNG_KERNEL_LIST_EVENTS:
1005 {
1006 char *event_list;
1007 ssize_t size = 0;
1008
1009 DBG("Listing kernel events");
1010
1011 size = kernel_list_events(kernel_tracer_fd, &event_list);
1012 if (size < 0) {
1013 ret = LTTCOMM_KERN_LIST_FAIL;
1014 goto error;
1015 }
1016
1017 /*
1018 * Setup lttng message with payload size set to the event list size in
1019 * bytes and then copy list into the llm payload.
1020 */
1021 ret = setup_lttng_msg(cmd_ctx, size);
1022 if (ret < 0) {
1023 goto setup_error;
1024 }
1025
1026 /* Copy event list into message payload */
1027 memcpy(cmd_ctx->llm->payload, event_list, size);
1028
1029 free(event_list);
1030
1031 ret = LTTCOMM_OK;
1032 break;
1033 }
1034 case LTTNG_START_TRACE:
1035 {
1036 struct ltt_kernel_channel *chan;
1037
1038 /* Setup lttng message with no payload */
1039 ret = setup_lttng_msg(cmd_ctx, 0);
1040 if (ret < 0) {
1041 goto setup_error;
1042 }
1043
1044 /* Kernel tracing */
1045 if (cmd_ctx->session->kernel_session != NULL) {
1046 if (cmd_ctx->session->kernel_session->metadata == NULL) {
1047 DBG("Open kernel metadata");
1048 ret = kernel_open_metadata(cmd_ctx->session->kernel_session);
1049 if (ret < 0) {
1050 ret = LTTCOMM_KERN_META_FAIL;
1051 goto error;
1052 }
1053 }
1054
1055 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1056 DBG("Opening kernel metadata stream");
1057 if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
1058 ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
1059 if (ret < 0) {
1060 ERR("Kernel create metadata stream failed");
1061 ret = LTTCOMM_KERN_STREAM_FAIL;
1062 goto error;
1063 }
1064 }
1065 }
1066
1067 /* For each channel */
1068 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1069 if (chan->stream_count == 0) {
1070 ret = kernel_open_channel_stream(chan);
1071 if (ret < 0) {
1072 ERR("Kernel create channel stream failed");
1073 ret = LTTCOMM_KERN_STREAM_FAIL;
1074 goto error;
1075 }
1076 /* Update the stream global counter */
1077 cmd_ctx->session->kernel_session->stream_count_global += ret;
1078 }
1079 }
1080
1081 DBG("Start kernel tracing");
1082 ret = kernel_start_session(cmd_ctx->session->kernel_session);
1083 if (ret < 0) {
1084 ERR("Kernel start session failed");
1085 ret = LTTCOMM_KERN_START_FAIL;
1086 goto error;
1087 }
1088
1089 ret = start_kernel_trace(cmd_ctx->session->kernel_session);
1090 if (ret < 0) {
1091 ret = LTTCOMM_KERN_START_FAIL;
1092 goto error;
1093 }
1094
1095 /* Quiescent wait after starting trace */
1096 kernel_wait_quiescent(kernel_tracer_fd);
1097 }
1098
1099 /* TODO: Start all UST traces */
1100
1101 ret = LTTCOMM_OK;
1102 break;
1103 }
1104 case LTTNG_STOP_TRACE:
1105 {
1106 struct ltt_kernel_channel *chan;
1107 /* Setup lttng message with no payload */
1108 ret = setup_lttng_msg(cmd_ctx, 0);
1109 if (ret < 0) {
1110 goto setup_error;
1111 }
1112
1113 /* Kernel tracer */
1114 if (cmd_ctx->session->kernel_session != NULL) {
1115 DBG("Stop kernel tracing");
1116
1117 ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
1118 if (ret < 0) {
1119 ERR("Kernel metadata flush failed");
1120 }
1121
1122 cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
1123 ret = kernel_flush_buffer(chan);
1124 if (ret < 0) {
1125 ERR("Kernel flush buffer error");
1126 }
1127 }
1128
1129 ret = kernel_stop_session(cmd_ctx->session->kernel_session);
1130 if (ret < 0) {
1131 ERR("Kernel stop session failed");
1132 ret = LTTCOMM_KERN_STOP_FAIL;
1133 goto error;
1134 }
1135
1136 /* Quiescent wait after stopping trace */
1137 kernel_wait_quiescent(kernel_tracer_fd);
1138 }
1139
1140 /* TODO : User-space tracer */
1141
1142 ret = LTTCOMM_OK;
1143 break;
1144 }
1145 case LTTNG_CREATE_SESSION:
1146 {
1147 /* Setup lttng message with no payload */
1148 ret = setup_lttng_msg(cmd_ctx, 0);
1149 if (ret < 0) {
1150 goto setup_error;
1151 }
1152
1153 ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path);
1154 if (ret < 0) {
1155 if (ret == -EEXIST) {
1156 ret = LTTCOMM_EXIST_SESS;
1157 } else {
1158 ret = LTTCOMM_FATAL;
1159 }
1160 goto error;
1161 }
1162
1163 ret = LTTCOMM_OK;
1164 break;
1165 }
1166 case LTTNG_DESTROY_SESSION:
1167 {
1168 /* Setup lttng message with no payload */
1169 ret = setup_lttng_msg(cmd_ctx, 0);
1170 if (ret < 0) {
1171 goto setup_error;
1172 }
1173
1174 /* Clean kernel session teardown */
1175 teardown_kernel_session(cmd_ctx->session);
1176
1177 ret = destroy_session(cmd_ctx->lsm->session_name);
1178 if (ret < 0) {
1179 ret = LTTCOMM_FATAL;
1180 goto error;
1181 }
1182
1183 ret = LTTCOMM_OK;
1184 break;
1185 }
1186 /*
1187 case LTTNG_LIST_TRACES:
1188 {
1189 unsigned int trace_count;
1190
1191 trace_count = get_trace_count_per_session(cmd_ctx->session);
1192 if (trace_count == 0) {
1193 ret = LTTCOMM_NO_TRACE;
1194 goto error;
1195 }
1196
1197 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
1198 if (ret < 0) {
1199 goto setup_error;
1200 }
1201
1202 get_traces_per_session(cmd_ctx->session,
1203 (struct lttng_trace *)(cmd_ctx->llm->payload));
1204
1205 ret = LTTCOMM_OK;
1206 break;
1207 }
1208 */
1209 /*
1210 case UST_CREATE_TRACE:
1211 {
1212 ret = setup_lttng_msg(cmd_ctx, 0);
1213 if (ret < 0) {
1214 goto setup_error;
1215 }
1216
1217 ret = ust_create_trace(cmd_ctx);
1218 if (ret < 0) {
1219 goto error;
1220 }
1221 break;
1222 }
1223 */
1224 case LTTNG_LIST_TRACEABLE_APPS:
1225 {
1226 unsigned int app_count;
1227
1228 app_count = get_app_count();
1229 DBG("Traceable application count : %d", app_count);
1230 if (app_count == 0) {
1231 ret = LTTCOMM_NO_APPS;
1232 goto error;
1233 }
1234
1235 ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
1236 if (ret < 0) {
1237 goto setup_error;
1238 }
1239
1240 get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
1241
1242 ret = LTTCOMM_OK;
1243 break;
1244 }
1245 /*
1246 case UST_START_TRACE:
1247 {
1248 ret = setup_lttng_msg(cmd_ctx, 0);
1249 if (ret < 0) {
1250 goto setup_error;
1251 }
1252
1253 ret = ust_start_trace(cmd_ctx);
1254 if (ret < 0) {
1255 goto setup_error;
1256 }
1257 break;
1258 }
1259 case UST_STOP_TRACE:
1260 {
1261 ret = setup_lttng_msg(cmd_ctx, 0);
1262 if (ret < 0) {
1263 goto setup_error;
1264 }
1265
1266 ret = ust_stop_trace(cmd_ctx);
1267 if (ret < 0) {
1268 goto setup_error;
1269 }
1270 break;
1271 }
1272 */
1273 case LTTNG_LIST_SESSIONS:
1274 {
1275 unsigned int session_count;
1276
1277 session_count = get_session_count();
1278 if (session_count == 0) {
1279 ret = LTTCOMM_NO_SESSION;
1280 goto error;
1281 }
1282
1283 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * session_count);
1284 if (ret < 0) {
1285 goto setup_error;
1286 }
1287
1288 get_lttng_session((struct lttng_session *)(cmd_ctx->llm->payload));
1289
1290 ret = LTTCOMM_OK;
1291 break;
1292 }
1293 default:
1294 /* Undefined command */
1295 ret = setup_lttng_msg(cmd_ctx, 0);
1296 if (ret < 0) {
1297 goto setup_error;
1298 }
1299
1300 ret = LTTCOMM_UND;
1301 break;
1302 }
1303
1304 /* Set return code */
1305 cmd_ctx->llm->ret_code = ret;
1306
1307 return ret;
1308
1309error:
1310 if (cmd_ctx->llm == NULL) {
1311 DBG("Missing llm structure. Allocating one.");
1312 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
1313 goto setup_error;
1314 }
1315 }
1316 /* Notify client of error */
1317 cmd_ctx->llm->ret_code = ret;
1318
1319setup_error:
1320 return ret;
1321}
1322
1323/*
1324 * thread_manage_clients
1325 *
1326 * This thread manage all clients request using the unix
1327 * client socket for communication.
1328 */
1329static void *thread_manage_clients(void *data)
1330{
1331 int sock, ret;
1332 struct command_ctx *cmd_ctx;
1333
1334 DBG("[thread] Manage client started");
1335
1336 ret = lttcomm_listen_unix_sock(client_sock);
1337 if (ret < 0) {
1338 goto error;
1339 }
1340
1341 /* Notify parent pid that we are ready
1342 * to accept command for client side.
1343 */
1344 if (opt_sig_parent) {
1345 kill(ppid, SIGCHLD);
1346 }
1347
1348 while (1) {
1349 /* Blocking call, waiting for transmission */
1350 DBG("Accepting client command ...");
1351 sock = lttcomm_accept_unix_sock(client_sock);
1352 if (sock < 0) {
1353 goto error;
1354 }
1355
1356 /* Allocate context command to process the client request */
1357 cmd_ctx = malloc(sizeof(struct command_ctx));
1358
1359 /* Allocate data buffer for reception */
1360 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
1361 cmd_ctx->llm = NULL;
1362 cmd_ctx->session = NULL;
1363
1364 /*
1365 * Data is received from the lttng client. The struct
1366 * lttcomm_session_msg (lsm) contains the command and data request of
1367 * the client.
1368 */
1369 DBG("Receiving data from client ...");
1370 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
1371 if (ret <= 0) {
1372 continue;
1373 }
1374
1375 // TODO: Validate cmd_ctx including sanity check for security purpose.
1376
1377 /*
1378 * This function dispatch the work to the kernel or userspace tracer
1379 * libs and fill the lttcomm_lttng_msg data structure of all the needed
1380 * informations for the client. The command context struct contains
1381 * everything this function may needs.
1382 */
1383 ret = process_client_msg(cmd_ctx);
1384 if (ret < 0) {
1385 /* TODO: Inform client somehow of the fatal error. At this point,
1386 * ret < 0 means that a malloc failed (ENOMEM). */
1387 /* Error detected but still accept command */
1388 clean_command_ctx(cmd_ctx);
1389 continue;
1390 }
1391
1392 DBG("Sending response (size: %d, retcode: %d)",
1393 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
1394 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
1395 if (ret < 0) {
1396 ERR("Failed to send data back to client");
1397 }
1398
1399 clean_command_ctx(cmd_ctx);
1400
1401 /* End of transmission */
1402 close(sock);
1403 }
1404
1405error:
1406 return NULL;
1407}
1408
1409
1410/*
1411 * usage function on stderr
1412 */
1413static void usage(void)
1414{
1415 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
1416 fprintf(stderr, " -h, --help Display this usage.\n");
1417 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
1418 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
1419 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
1420 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
1421 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
1422 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
1423 fprintf(stderr, " -V, --version Show version number.\n");
1424 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
1425 fprintf(stderr, " -q, --quiet No output at all.\n");
1426 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
1427}
1428
1429/*
1430 * daemon argument parsing
1431 */
1432static int parse_args(int argc, char **argv)
1433{
1434 int c;
1435
1436 static struct option long_options[] = {
1437 { "client-sock", 1, 0, 'c' },
1438 { "apps-sock", 1, 0, 'a' },
1439 { "kconsumerd-cmd-sock", 1, 0, 0 },
1440 { "kconsumerd-err-sock", 1, 0, 0 },
1441 { "daemonize", 0, 0, 'd' },
1442 { "sig-parent", 0, 0, 'S' },
1443 { "help", 0, 0, 'h' },
1444 { "group", 1, 0, 'g' },
1445 { "version", 0, 0, 'V' },
1446 { "quiet", 0, 0, 'q' },
1447 { "verbose", 0, 0, 'v' },
1448 { NULL, 0, 0, 0 }
1449 };
1450
1451 while (1) {
1452 int option_index = 0;
1453 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
1454 if (c == -1) {
1455 break;
1456 }
1457
1458 switch (c) {
1459 case 0:
1460 fprintf(stderr, "option %s", long_options[option_index].name);
1461 if (optarg) {
1462 fprintf(stderr, " with arg %s\n", optarg);
1463 }
1464 break;
1465 case 'c':
1466 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
1467 break;
1468 case 'a':
1469 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
1470 break;
1471 case 'd':
1472 opt_daemon = 1;
1473 break;
1474 case 'g':
1475 opt_tracing_group = strdup(optarg);
1476 break;
1477 case 'h':
1478 usage();
1479 exit(EXIT_FAILURE);
1480 case 'V':
1481 fprintf(stdout, "%s\n", VERSION);
1482 exit(EXIT_SUCCESS);
1483 case 'S':
1484 opt_sig_parent = 1;
1485 break;
1486 case 'E':
1487 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
1488 break;
1489 case 'C':
1490 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
1491 break;
1492 case 'q':
1493 opt_quiet = 1;
1494 break;
1495 case 'v':
1496 opt_verbose = 1;
1497 break;
1498 default:
1499 /* Unknown option or other error.
1500 * Error is printed by getopt, just return */
1501 return -1;
1502 }
1503 }
1504
1505 return 0;
1506}
1507
1508/*
1509 * init_daemon_socket
1510 *
1511 * Creates the two needed socket by the daemon.
1512 * apps_sock - The communication socket for all UST apps.
1513 * client_sock - The communication of the cli tool (lttng).
1514 */
1515static int init_daemon_socket()
1516{
1517 int ret = 0;
1518 mode_t old_umask;
1519
1520 old_umask = umask(0);
1521
1522 /* Create client tool unix socket */
1523 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
1524 if (client_sock < 0) {
1525 ERR("Create unix sock failed: %s", client_unix_sock_path);
1526 ret = -1;
1527 goto end;
1528 }
1529
1530 /* File permission MUST be 660 */
1531 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
1532 if (ret < 0) {
1533 ERR("Set file permissions failed: %s", client_unix_sock_path);
1534 perror("chmod");
1535 goto end;
1536 }
1537
1538 /* Create the application unix socket */
1539 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
1540 if (apps_sock < 0) {
1541 ERR("Create unix sock failed: %s", apps_unix_sock_path);
1542 ret = -1;
1543 goto end;
1544 }
1545
1546 /* File permission MUST be 666 */
1547 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
1548 if (ret < 0) {
1549 ERR("Set file permissions failed: %s", apps_unix_sock_path);
1550 perror("chmod");
1551 goto end;
1552 }
1553
1554end:
1555 umask(old_umask);
1556 return ret;
1557}
1558
1559/*
1560 * check_existing_daemon
1561 *
1562 * Check if the global socket is available.
1563 * If yes, error is returned.
1564 */
1565static int check_existing_daemon()
1566{
1567 int ret;
1568
1569 ret = access(client_unix_sock_path, F_OK);
1570 if (ret == 0) {
1571 ret = access(apps_unix_sock_path, F_OK);
1572 }
1573
1574 return ret;
1575}
1576
1577/*
1578 * get_home_dir
1579 *
1580 * Return pointer to home directory path using
1581 * the env variable HOME.
1582 *
1583 * Default : /tmp
1584 */
1585static const char *get_home_dir(void)
1586{
1587 const char *home_path;
1588
1589 if ((home_path = (const char *) getenv("HOME")) == NULL) {
1590 home_path = default_home_dir;
1591 }
1592
1593 return home_path;
1594}
1595
1596/*
1597 * set_permissions
1598 *
1599 * Set the tracing group gid onto the client socket.
1600 *
1601 * Race window between mkdir and chown is OK because we are going from
1602 * less permissive (root.root) to more permissive (root.tracing).
1603 */
1604static int set_permissions(void)
1605{
1606 int ret;
1607 struct group *grp;
1608
1609 /* Decide which group name to use */
1610 (opt_tracing_group != NULL) ?
1611 (grp = getgrnam(opt_tracing_group)) :
1612 (grp = getgrnam(default_tracing_group));
1613
1614 if (grp == NULL) {
1615 ERR("Missing tracing group. Aborting execution.\n");
1616 ret = -1;
1617 goto end;
1618 }
1619
1620 /* Set lttng run dir */
1621 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
1622 if (ret < 0) {
1623 ERR("Unable to set group on " LTTNG_RUNDIR);
1624 perror("chown");
1625 }
1626
1627 /* lttng client socket path */
1628 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
1629 if (ret < 0) {
1630 ERR("Unable to set group on %s", client_unix_sock_path);
1631 perror("chown");
1632 }
1633
1634 /* kconsumerd error socket path */
1635 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
1636 if (ret < 0) {
1637 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
1638 perror("chown");
1639 }
1640
1641 DBG("All permissions are set");
1642
1643end:
1644 return ret;
1645}
1646
1647/*
1648 * create_lttng_rundir
1649 *
1650 * Create the lttng run directory needed for all
1651 * global sockets and pipe.
1652 */
1653static int create_lttng_rundir(void)
1654{
1655 int ret;
1656
1657 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
1658 if (ret < 0) {
1659 if (errno != EEXIST) {
1660 ERR("Unable to create " LTTNG_RUNDIR);
1661 goto error;
1662 } else {
1663 ret = 0;
1664 }
1665 }
1666
1667error:
1668 return ret;
1669}
1670
1671/*
1672 * set_kconsumerd_sockets
1673 *
1674 * Setup sockets and directory needed by the kconsumerd
1675 * communication with the session daemon.
1676 */
1677static int set_kconsumerd_sockets(void)
1678{
1679 int ret;
1680
1681 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
1682 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
1683 }
1684
1685 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
1686 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
1687 }
1688
1689 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
1690 if (ret < 0) {
1691 if (errno != EEXIST) {
1692 ERR("Failed to create " KCONSUMERD_PATH);
1693 goto error;
1694 }
1695 ret = 0;
1696 }
1697
1698 /* Create the kconsumerd error unix socket */
1699 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
1700 if (kconsumerd_err_sock < 0) {
1701 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
1702 ret = -1;
1703 goto error;
1704 }
1705
1706 /* File permission MUST be 660 */
1707 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
1708 if (ret < 0) {
1709 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
1710 perror("chmod");
1711 goto error;
1712 }
1713
1714error:
1715 return ret;
1716}
1717
1718/*
1719 * sighandler
1720 *
1721 * Signal handler for the daemon
1722 */
1723static void sighandler(int sig)
1724{
1725 switch (sig) {
1726 case SIGPIPE:
1727 DBG("SIGPIPE catched");
1728 return;
1729 case SIGINT:
1730 DBG("SIGINT catched");
1731 cleanup();
1732 break;
1733 case SIGTERM:
1734 DBG("SIGTERM catched");
1735 cleanup();
1736 break;
1737 default:
1738 break;
1739 }
1740
1741 exit(EXIT_SUCCESS);
1742}
1743
1744/*
1745 * set_signal_handler
1746 *
1747 * Setup signal handler for :
1748 * SIGINT, SIGTERM, SIGPIPE
1749 */
1750static int set_signal_handler(void)
1751{
1752 int ret = 0;
1753 struct sigaction sa;
1754 sigset_t sigset;
1755
1756 if ((ret = sigemptyset(&sigset)) < 0) {
1757 perror("sigemptyset");
1758 return ret;
1759 }
1760
1761 sa.sa_handler = sighandler;
1762 sa.sa_mask = sigset;
1763 sa.sa_flags = 0;
1764 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1765 perror("sigaction");
1766 return ret;
1767 }
1768
1769 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1770 perror("sigaction");
1771 return ret;
1772 }
1773
1774 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
1775 perror("sigaction");
1776 return ret;
1777 }
1778
1779 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
1780
1781 return ret;
1782}
1783
1784/*
1785 * set_ulimit
1786 *
1787 * Set open files limit to unlimited. This daemon can open a large number of
1788 * file descriptors in order to consumer multiple kernel traces.
1789 */
1790static void set_ulimit(void)
1791{
1792 int ret;
1793 struct rlimit lim;
1794
1795 lim.rlim_cur = 65535;
1796 lim.rlim_max = 65535;
1797
1798 ret = setrlimit(RLIMIT_NOFILE, &lim);
1799 if (ret < 0) {
1800 perror("failed to set open files limit");
1801 }
1802}
1803
1804/*
1805 * main
1806 */
1807int main(int argc, char **argv)
1808{
1809 int ret = 0;
1810 void *status;
1811
1812 /* Parse arguments */
1813 progname = argv[0];
1814 if ((ret = parse_args(argc, argv) < 0)) {
1815 goto error;
1816 }
1817
1818 /* Daemonize */
1819 if (opt_daemon) {
1820 ret = daemon(0, 0);
1821 if (ret < 0) {
1822 perror("daemon");
1823 goto error;
1824 }
1825 }
1826
1827 /* Check if daemon is UID = 0 */
1828 is_root = !getuid();
1829
1830 /* Set all sockets path */
1831 if (is_root) {
1832 ret = create_lttng_rundir();
1833 if (ret < 0) {
1834 goto error;
1835 }
1836
1837 if (strlen(apps_unix_sock_path) == 0) {
1838 snprintf(apps_unix_sock_path, PATH_MAX,
1839 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
1840 }
1841
1842 if (strlen(client_unix_sock_path) == 0) {
1843 snprintf(client_unix_sock_path, PATH_MAX,
1844 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
1845 }
1846
1847 ret = set_kconsumerd_sockets();
1848 if (ret < 0) {
1849 goto error;
1850 }
1851
1852 /* Setup kernel tracer */
1853 init_kernel_tracer();
1854
1855 /* Set ulimit for open files */
1856 set_ulimit();
1857 } else {
1858 if (strlen(apps_unix_sock_path) == 0) {
1859 snprintf(apps_unix_sock_path, PATH_MAX,
1860 DEFAULT_HOME_APPS_UNIX_SOCK, get_home_dir());
1861 }
1862
1863 /* Set the cli tool unix socket path */
1864 if (strlen(client_unix_sock_path) == 0) {
1865 snprintf(client_unix_sock_path, PATH_MAX,
1866 DEFAULT_HOME_CLIENT_UNIX_SOCK, get_home_dir());
1867 }
1868 }
1869
1870 DBG("Client socket path %s", client_unix_sock_path);
1871 DBG("Application socket path %s", apps_unix_sock_path);
1872
1873 /* See if daemon already exist. If any of the two
1874 * socket needed by the daemon are present, this test fails
1875 */
1876 if ((ret = check_existing_daemon()) == 0) {
1877 ERR("Already running daemon.\n");
1878 /* We do not goto error because we must not
1879 * cleanup() because a daemon is already running.
1880 */
1881 exit(EXIT_FAILURE);
1882 }
1883
1884 if (set_signal_handler() < 0) {
1885 goto error;
1886 }
1887
1888 /* Setup the needed unix socket */
1889 if (init_daemon_socket() < 0) {
1890 goto error;
1891 }
1892
1893 /* Set credentials to socket */
1894 if (is_root && (set_permissions() < 0)) {
1895 goto error;
1896 }
1897
1898 /* Get parent pid if -S, --sig-parent is specified. */
1899 if (opt_sig_parent) {
1900 ppid = getppid();
1901 }
1902
1903 while (1) {
1904 /* Create thread to manage the client socket */
1905 ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
1906 if (ret != 0) {
1907 perror("pthread_create");
1908 goto error;
1909 }
1910
1911 /* Create thread to manage application socket */
1912 ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
1913 if (ret != 0) {
1914 perror("pthread_create");
1915 goto error;
1916 }
1917
1918 ret = pthread_join(client_thread, &status);
1919 if (ret != 0) {
1920 perror("pthread_join");
1921 goto error;
1922 }
1923 }
1924
1925 cleanup();
1926 exit(EXIT_SUCCESS);
1927
1928error:
1929 cleanup();
1930 exit(EXIT_FAILURE);
1931}
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