5644cb82d9998b74f55e5a9c13a0ab77cb7d7dde
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; only version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * 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/mman.h>
31 #include <sys/mount.h>
32 #include <sys/resource.h>
33 #include <sys/socket.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 #include <urcu/futex.h>
38 #include <unistd.h>
39 #include <config.h>
40
41 #include <common/common.h>
42 #include <common/compat/poll.h>
43 #include <common/defaults.h>
44 #include <common/kernel-consumer/kernel-consumer.h>
45 #include <common/ust-consumer/ust-consumer.h>
46
47 #include "lttng-sessiond.h"
48 #include "channel.h"
49 #include "context.h"
50 #include "event.h"
51 #include "futex.h"
52 #include "kernel.h"
53 #include "modprobe.h"
54 #include "shm.h"
55 #include "ust-ctl.h"
56 #include "utils.h"
57
58 #define CONSUMERD_FILE "lttng-consumerd"
59
60 struct consumer_data {
61 enum lttng_consumer_type type;
62
63 pthread_t thread; /* Worker thread interacting with the consumer */
64 sem_t sem;
65
66 /* Mutex to control consumerd pid assignation */
67 pthread_mutex_t pid_mutex;
68 pid_t pid;
69
70 int err_sock;
71 int cmd_sock;
72
73 /* consumer error and command Unix socket path */
74 char err_unix_sock_path[PATH_MAX];
75 char cmd_unix_sock_path[PATH_MAX];
76 };
77
78 /* Const values */
79 const char default_home_dir[] = DEFAULT_HOME_DIR;
80 const char default_tracing_group[] = DEFAULT_TRACING_GROUP;
81 const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
82 const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
83
84 /* Variables */
85 int opt_verbose; /* Not static for lttngerr.h */
86 int opt_verbose_consumer; /* Not static for lttngerr.h */
87 int opt_quiet; /* Not static for lttngerr.h */
88
89 const char *progname;
90 const char *opt_tracing_group;
91 static int opt_sig_parent;
92 static int opt_daemon;
93 static int opt_no_kernel;
94 static int is_root; /* Set to 1 if the daemon is running as root */
95 static pid_t ppid; /* Parent PID for --sig-parent option */
96 static char *rundir;
97
98 /* Consumer daemon specific control data */
99 static struct consumer_data kconsumer_data = {
100 .type = LTTNG_CONSUMER_KERNEL,
101 .err_unix_sock_path = DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
102 .cmd_unix_sock_path = DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
103 };
104 static struct consumer_data ustconsumer64_data = {
105 .type = LTTNG_CONSUMER64_UST,
106 .err_unix_sock_path = DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH,
107 .cmd_unix_sock_path = DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
108 };
109 static struct consumer_data ustconsumer32_data = {
110 .type = LTTNG_CONSUMER32_UST,
111 .err_unix_sock_path = DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH,
112 .cmd_unix_sock_path = DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
113 };
114
115 static int dispatch_thread_exit;
116
117 /* Global application Unix socket path */
118 static char apps_unix_sock_path[PATH_MAX];
119 /* Global client Unix socket path */
120 static char client_unix_sock_path[PATH_MAX];
121 /* global wait shm path for UST */
122 static char wait_shm_path[PATH_MAX];
123
124 /* Sockets and FDs */
125 static int client_sock = -1;
126 static int apps_sock = -1;
127 static int kernel_tracer_fd = -1;
128 static int kernel_poll_pipe[2] = { -1, -1 };
129
130 /*
131 * Quit pipe for all threads. This permits a single cancellation point
132 * for all threads when receiving an event on the pipe.
133 */
134 static int thread_quit_pipe[2] = { -1, -1 };
135
136 /*
137 * This pipe is used to inform the thread managing application communication
138 * that a command is queued and ready to be processed.
139 */
140 static int apps_cmd_pipe[2] = { -1, -1 };
141
142 /* Pthread, Mutexes and Semaphores */
143 static pthread_t apps_thread;
144 static pthread_t reg_apps_thread;
145 static pthread_t client_thread;
146 static pthread_t kernel_thread;
147 static pthread_t dispatch_thread;
148
149
150 /*
151 * UST registration command queue. This queue is tied with a futex and uses a N
152 * wakers / 1 waiter implemented and detailed in futex.c/.h
153 *
154 * The thread_manage_apps and thread_dispatch_ust_registration interact with
155 * this queue and the wait/wake scheme.
156 */
157 static struct ust_cmd_queue ust_cmd_queue;
158
159 /*
160 * Pointer initialized before thread creation.
161 *
162 * This points to the tracing session list containing the session count and a
163 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
164 * MUST NOT be taken if you call a public function in session.c.
165 *
166 * The lock is nested inside the structure: session_list_ptr->lock. Please use
167 * session_lock_list and session_unlock_list for lock acquisition.
168 */
169 static struct ltt_session_list *session_list_ptr;
170
171 int ust_consumerd64_fd = -1;
172 int ust_consumerd32_fd = -1;
173
174 static const char *consumerd32_bin = CONFIG_CONSUMERD32_BIN;
175 static const char *consumerd64_bin = CONFIG_CONSUMERD64_BIN;
176 static const char *consumerd32_libdir = CONFIG_CONSUMERD32_LIBDIR;
177 static const char *consumerd64_libdir = CONFIG_CONSUMERD64_LIBDIR;
178
179 static
180 void setup_consumerd_path(void)
181 {
182 const char *bin, *libdir;
183
184 /*
185 * Allow INSTALL_BIN_PATH to be used as a target path for the
186 * native architecture size consumer if CONFIG_CONSUMER*_PATH
187 * has not been defined.
188 */
189 #if (CAA_BITS_PER_LONG == 32)
190 if (!consumerd32_bin[0]) {
191 consumerd32_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
192 }
193 if (!consumerd32_libdir[0]) {
194 consumerd32_libdir = INSTALL_LIB_PATH;
195 }
196 #elif (CAA_BITS_PER_LONG == 64)
197 if (!consumerd64_bin[0]) {
198 consumerd64_bin = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
199 }
200 if (!consumerd64_libdir[0]) {
201 consumerd64_libdir = INSTALL_LIB_PATH;
202 }
203 #else
204 #error "Unknown bitness"
205 #endif
206
207 /*
208 * runtime env. var. overrides the build default.
209 */
210 bin = getenv("LTTNG_CONSUMERD32_BIN");
211 if (bin) {
212 consumerd32_bin = bin;
213 }
214 bin = getenv("LTTNG_CONSUMERD64_BIN");
215 if (bin) {
216 consumerd64_bin = bin;
217 }
218 libdir = getenv("LTTNG_CONSUMERD32_LIBDIR");
219 if (libdir) {
220 consumerd32_libdir = libdir;
221 }
222 libdir = getenv("LTTNG_CONSUMERD64_LIBDIR");
223 if (libdir) {
224 consumerd64_libdir = libdir;
225 }
226 }
227
228 /*
229 * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
230 */
231 static int create_thread_poll_set(struct lttng_poll_event *events,
232 unsigned int size)
233 {
234 int ret;
235
236 if (events == NULL || size == 0) {
237 ret = -1;
238 goto error;
239 }
240
241 ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
242 if (ret < 0) {
243 goto error;
244 }
245
246 /* Add quit pipe */
247 ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
248 if (ret < 0) {
249 goto error;
250 }
251
252 return 0;
253
254 error:
255 return ret;
256 }
257
258 /*
259 * Check if the thread quit pipe was triggered.
260 *
261 * Return 1 if it was triggered else 0;
262 */
263 static int check_thread_quit_pipe(int fd, uint32_t events)
264 {
265 if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
266 return 1;
267 }
268
269 return 0;
270 }
271
272 /*
273 * Return group ID of the tracing group or -1 if not found.
274 */
275 static gid_t allowed_group(void)
276 {
277 struct group *grp;
278
279 if (opt_tracing_group) {
280 grp = getgrnam(opt_tracing_group);
281 } else {
282 grp = getgrnam(default_tracing_group);
283 }
284 if (!grp) {
285 return -1;
286 } else {
287 return grp->gr_gid;
288 }
289 }
290
291 /*
292 * Init thread quit pipe.
293 *
294 * Return -1 on error or 0 if all pipes are created.
295 */
296 static int init_thread_quit_pipe(void)
297 {
298 int ret;
299
300 ret = pipe2(thread_quit_pipe, O_CLOEXEC);
301 if (ret < 0) {
302 PERROR("thread quit pipe");
303 goto error;
304 }
305
306 error:
307 return ret;
308 }
309
310 /*
311 * Complete teardown of a kernel session. This free all data structure related
312 * to a kernel session and update counter.
313 */
314 static void teardown_kernel_session(struct ltt_session *session)
315 {
316 if (!session->kernel_session) {
317 DBG3("No kernel session when tearing down session");
318 return;
319 }
320
321 DBG("Tearing down kernel session");
322
323 /*
324 * If a custom kernel consumer was registered, close the socket before
325 * tearing down the complete kernel session structure
326 */
327 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
328 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
329 }
330
331 trace_kernel_destroy_session(session->kernel_session);
332 }
333
334 /*
335 * Complete teardown of all UST sessions. This will free everything on his path
336 * and destroy the core essence of all ust sessions :)
337 */
338 static void teardown_ust_session(struct ltt_session *session)
339 {
340 int ret;
341
342 if (!session->ust_session) {
343 DBG3("No UST session when tearing down session");
344 return;
345 }
346
347 DBG("Tearing down UST session(s)");
348
349 ret = ust_app_destroy_trace_all(session->ust_session);
350 if (ret) {
351 ERR("Error in ust_app_destroy_trace_all");
352 }
353
354 trace_ust_destroy_session(session->ust_session);
355 }
356
357 /*
358 * Stop all threads by closing the thread quit pipe.
359 */
360 static void stop_threads(void)
361 {
362 int ret;
363
364 /* Stopping all threads */
365 DBG("Terminating all threads");
366 ret = notify_thread_pipe(thread_quit_pipe[1]);
367 if (ret < 0) {
368 ERR("write error on thread quit pipe");
369 }
370
371 /* Dispatch thread */
372 dispatch_thread_exit = 1;
373 futex_nto1_wake(&ust_cmd_queue.futex);
374 }
375
376 /*
377 * Cleanup the daemon
378 */
379 static void cleanup(void)
380 {
381 int ret, i;
382 char *cmd;
383 struct ltt_session *sess, *stmp;
384
385 DBG("Cleaning up");
386
387 DBG("Removing %s directory", rundir);
388 ret = asprintf(&cmd, "rm -rf %s", rundir);
389 if (ret < 0) {
390 ERR("asprintf failed. Something is really wrong!");
391 }
392
393 /* Remove lttng run directory */
394 ret = system(cmd);
395 if (ret < 0) {
396 ERR("Unable to clean %s", rundir);
397 }
398 free(cmd);
399
400 DBG("Cleaning up all sessions");
401
402 /* Destroy session list mutex */
403 if (session_list_ptr != NULL) {
404 pthread_mutex_destroy(&session_list_ptr->lock);
405
406 /* Cleanup ALL session */
407 cds_list_for_each_entry_safe(sess, stmp,
408 &session_list_ptr->head, list) {
409 teardown_kernel_session(sess);
410 teardown_ust_session(sess);
411 free(sess);
412 }
413 }
414
415 DBG("Closing all UST sockets");
416 ust_app_clean_list();
417
418 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
419
420 if (is_root && !opt_no_kernel) {
421 DBG2("Closing kernel fd");
422 if (kernel_tracer_fd >= 0) {
423 ret = close(kernel_tracer_fd);
424 if (ret) {
425 PERROR("close");
426 }
427 }
428 DBG("Unloading kernel modules");
429 modprobe_remove_lttng_all();
430 }
431
432 /*
433 * Closing all pipes used for communication between threads.
434 */
435 for (i = 0; i < 2; i++) {
436 if (kernel_poll_pipe[i] >= 0) {
437 ret = close(kernel_poll_pipe[i]);
438 if (ret) {
439 PERROR("close");
440 }
441
442 }
443 }
444 for (i = 0; i < 2; i++) {
445 if (thread_quit_pipe[i] >= 0) {
446 ret = close(thread_quit_pipe[i]);
447 if (ret) {
448 PERROR("close");
449 }
450 }
451 }
452 for (i = 0; i < 2; i++) {
453 if (apps_cmd_pipe[i] >= 0) {
454 ret = close(apps_cmd_pipe[i]);
455 if (ret) {
456 PERROR("close");
457 }
458 }
459 }
460
461 /* <fun> */
462 DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
463 "Matthew, BEET driven development works!%c[%dm",
464 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
465 /* </fun> */
466 }
467
468 /*
469 * Send data on a unix socket using the liblttsessiondcomm API.
470 *
471 * Return lttcomm error code.
472 */
473 static int send_unix_sock(int sock, void *buf, size_t len)
474 {
475 /* Check valid length */
476 if (len <= 0) {
477 return -1;
478 }
479
480 return lttcomm_send_unix_sock(sock, buf, len);
481 }
482
483 /*
484 * Free memory of a command context structure.
485 */
486 static void clean_command_ctx(struct command_ctx **cmd_ctx)
487 {
488 DBG("Clean command context structure");
489 if (*cmd_ctx) {
490 if ((*cmd_ctx)->llm) {
491 free((*cmd_ctx)->llm);
492 }
493 if ((*cmd_ctx)->lsm) {
494 free((*cmd_ctx)->lsm);
495 }
496 free(*cmd_ctx);
497 *cmd_ctx = NULL;
498 }
499 }
500
501 /*
502 * Send all stream fds of kernel channel to the consumer.
503 */
504 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
505 int sock, struct ltt_kernel_channel *channel,
506 uid_t uid, gid_t gid)
507 {
508 int ret;
509 struct ltt_kernel_stream *stream;
510 struct lttcomm_consumer_msg lkm;
511
512 DBG("Sending streams of channel %s to kernel consumer",
513 channel->channel->name);
514
515 /* Send channel */
516 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
517 lkm.u.channel.channel_key = channel->fd;
518 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
519 lkm.u.channel.mmap_len = 0; /* for kernel */
520 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
521 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
522 if (ret < 0) {
523 PERROR("send consumer channel");
524 goto error;
525 }
526
527 /* Send streams */
528 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
529 if (!stream->fd) {
530 continue;
531 }
532 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
533 lkm.u.stream.channel_key = channel->fd;
534 lkm.u.stream.stream_key = stream->fd;
535 lkm.u.stream.state = stream->state;
536 lkm.u.stream.output = channel->channel->attr.output;
537 lkm.u.stream.mmap_len = 0; /* for kernel */
538 lkm.u.stream.uid = uid;
539 lkm.u.stream.gid = gid;
540 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
541 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
542 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
543 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
544 if (ret < 0) {
545 PERROR("send consumer stream");
546 goto error;
547 }
548 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
549 if (ret < 0) {
550 PERROR("send consumer stream ancillary data");
551 goto error;
552 }
553 }
554
555 DBG("consumer channel streams sent");
556
557 return 0;
558
559 error:
560 return ret;
561 }
562
563 /*
564 * Send all stream fds of the kernel session to the consumer.
565 */
566 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
567 struct ltt_kernel_session *session)
568 {
569 int ret;
570 struct ltt_kernel_channel *chan;
571 struct lttcomm_consumer_msg lkm;
572 int sock = session->consumer_fd;
573
574 DBG("Sending metadata stream fd");
575
576 /* Extra protection. It's NOT supposed to be set to 0 at this point */
577 if (session->consumer_fd == 0) {
578 session->consumer_fd = consumer_data->cmd_sock;
579 }
580
581 if (session->metadata_stream_fd != 0) {
582 /* Send metadata channel fd */
583 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
584 lkm.u.channel.channel_key = session->metadata->fd;
585 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
586 lkm.u.channel.mmap_len = 0; /* for kernel */
587 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
588 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
589 if (ret < 0) {
590 PERROR("send consumer channel");
591 goto error;
592 }
593
594 /* Send metadata stream fd */
595 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
596 lkm.u.stream.channel_key = session->metadata->fd;
597 lkm.u.stream.stream_key = session->metadata_stream_fd;
598 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
599 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
600 lkm.u.stream.mmap_len = 0; /* for kernel */
601 lkm.u.stream.uid = session->uid;
602 lkm.u.stream.gid = session->gid;
603 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
604 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
605 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
606 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
607 if (ret < 0) {
608 PERROR("send consumer stream");
609 goto error;
610 }
611 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
612 if (ret < 0) {
613 PERROR("send consumer stream");
614 goto error;
615 }
616 }
617
618 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
619 ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
620 session->uid, session->gid);
621 if (ret < 0) {
622 goto error;
623 }
624 }
625
626 DBG("consumer fds (metadata and channel streams) sent");
627
628 return 0;
629
630 error:
631 return ret;
632 }
633
634 /*
635 * Notify UST applications using the shm mmap futex.
636 */
637 static int notify_ust_apps(int active)
638 {
639 char *wait_shm_mmap;
640
641 DBG("Notifying applications of session daemon state: %d", active);
642
643 /* See shm.c for this call implying mmap, shm and futex calls */
644 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
645 if (wait_shm_mmap == NULL) {
646 goto error;
647 }
648
649 /* Wake waiting process */
650 futex_wait_update((int32_t *) wait_shm_mmap, active);
651
652 /* Apps notified successfully */
653 return 0;
654
655 error:
656 return -1;
657 }
658
659 /*
660 * Setup the outgoing data buffer for the response (llm) by allocating the
661 * right amount of memory and copying the original information from the lsm
662 * structure.
663 *
664 * Return total size of the buffer pointed by buf.
665 */
666 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
667 {
668 int ret, buf_size;
669
670 buf_size = size;
671
672 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
673 if (cmd_ctx->llm == NULL) {
674 PERROR("zmalloc");
675 ret = -ENOMEM;
676 goto error;
677 }
678
679 /* Copy common data */
680 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
681 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
682
683 cmd_ctx->llm->data_size = size;
684 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
685
686 return buf_size;
687
688 error:
689 return ret;
690 }
691
692 /*
693 * Update the kernel poll set of all channel fd available over all tracing
694 * session. Add the wakeup pipe at the end of the set.
695 */
696 static int update_kernel_poll(struct lttng_poll_event *events)
697 {
698 int ret;
699 struct ltt_session *session;
700 struct ltt_kernel_channel *channel;
701
702 DBG("Updating kernel poll set");
703
704 session_lock_list();
705 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
706 session_lock(session);
707 if (session->kernel_session == NULL) {
708 session_unlock(session);
709 continue;
710 }
711
712 cds_list_for_each_entry(channel,
713 &session->kernel_session->channel_list.head, list) {
714 /* Add channel fd to the kernel poll set */
715 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
716 if (ret < 0) {
717 session_unlock(session);
718 goto error;
719 }
720 DBG("Channel fd %d added to kernel set", channel->fd);
721 }
722 session_unlock(session);
723 }
724 session_unlock_list();
725
726 return 0;
727
728 error:
729 session_unlock_list();
730 return -1;
731 }
732
733 /*
734 * Find the channel fd from 'fd' over all tracing session. When found, check
735 * for new channel stream and send those stream fds to the kernel consumer.
736 *
737 * Useful for CPU hotplug feature.
738 */
739 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
740 {
741 int ret = 0;
742 struct ltt_session *session;
743 struct ltt_kernel_channel *channel;
744
745 DBG("Updating kernel streams for channel fd %d", fd);
746
747 session_lock_list();
748 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
749 session_lock(session);
750 if (session->kernel_session == NULL) {
751 session_unlock(session);
752 continue;
753 }
754
755 /* This is not suppose to be 0 but this is an extra security check */
756 if (session->kernel_session->consumer_fd == 0) {
757 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
758 }
759
760 cds_list_for_each_entry(channel,
761 &session->kernel_session->channel_list.head, list) {
762 if (channel->fd == fd) {
763 DBG("Channel found, updating kernel streams");
764 ret = kernel_open_channel_stream(channel);
765 if (ret < 0) {
766 goto error;
767 }
768
769 /*
770 * Have we already sent fds to the consumer? If yes, it means
771 * that tracing is started so it is safe to send our updated
772 * stream fds.
773 */
774 if (session->kernel_session->consumer_fds_sent == 1) {
775 ret = send_kconsumer_channel_streams(consumer_data,
776 session->kernel_session->consumer_fd, channel,
777 session->uid, session->gid);
778 if (ret < 0) {
779 goto error;
780 }
781 }
782 goto error;
783 }
784 }
785 session_unlock(session);
786 }
787 session_unlock_list();
788 return ret;
789
790 error:
791 session_unlock(session);
792 session_unlock_list();
793 return ret;
794 }
795
796 /*
797 * For each tracing session, update newly registered apps.
798 */
799 static void update_ust_app(int app_sock)
800 {
801 struct ltt_session *sess, *stmp;
802
803 session_lock_list();
804
805 /* For all tracing session(s) */
806 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
807 session_lock(sess);
808 if (sess->ust_session) {
809 ust_app_global_update(sess->ust_session, app_sock);
810 }
811 session_unlock(sess);
812 }
813
814 session_unlock_list();
815 }
816
817 /*
818 * This thread manage event coming from the kernel.
819 *
820 * Features supported in this thread:
821 * -) CPU Hotplug
822 */
823 static void *thread_manage_kernel(void *data)
824 {
825 int ret, i, pollfd, update_poll_flag = 1;
826 uint32_t revents, nb_fd;
827 char tmp;
828 struct lttng_poll_event events;
829
830 DBG("Thread manage kernel started");
831
832 ret = create_thread_poll_set(&events, 2);
833 if (ret < 0) {
834 goto error_poll_create;
835 }
836
837 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
838 if (ret < 0) {
839 goto error;
840 }
841
842 while (1) {
843 if (update_poll_flag == 1) {
844 /*
845 * Reset number of fd in the poll set. Always 2 since there is the thread
846 * quit pipe and the kernel pipe.
847 */
848 events.nb_fd = 2;
849
850 ret = update_kernel_poll(&events);
851 if (ret < 0) {
852 goto error;
853 }
854 update_poll_flag = 0;
855 }
856
857 nb_fd = LTTNG_POLL_GETNB(&events);
858
859 DBG("Thread kernel polling on %d fds", nb_fd);
860
861 /* Zeroed the poll events */
862 lttng_poll_reset(&events);
863
864 /* Poll infinite value of time */
865 restart:
866 ret = lttng_poll_wait(&events, -1);
867 if (ret < 0) {
868 /*
869 * Restart interrupted system call.
870 */
871 if (errno == EINTR) {
872 goto restart;
873 }
874 goto error;
875 } else if (ret == 0) {
876 /* Should not happen since timeout is infinite */
877 ERR("Return value of poll is 0 with an infinite timeout.\n"
878 "This should not have happened! Continuing...");
879 continue;
880 }
881
882 for (i = 0; i < nb_fd; i++) {
883 /* Fetch once the poll data */
884 revents = LTTNG_POLL_GETEV(&events, i);
885 pollfd = LTTNG_POLL_GETFD(&events, i);
886
887 /* Thread quit pipe has been closed. Killing thread. */
888 ret = check_thread_quit_pipe(pollfd, revents);
889 if (ret) {
890 goto error;
891 }
892
893 /* Check for data on kernel pipe */
894 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
895 ret = read(kernel_poll_pipe[0], &tmp, 1);
896 update_poll_flag = 1;
897 continue;
898 } else {
899 /*
900 * New CPU detected by the kernel. Adding kernel stream to
901 * kernel session and updating the kernel consumer
902 */
903 if (revents & LPOLLIN) {
904 ret = update_kernel_stream(&kconsumer_data, pollfd);
905 if (ret < 0) {
906 continue;
907 }
908 break;
909 /*
910 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
911 * and unregister kernel stream at this point.
912 */
913 }
914 }
915 }
916 }
917
918 error:
919 lttng_poll_clean(&events);
920 error_poll_create:
921 DBG("Kernel thread dying");
922 return NULL;
923 }
924
925 /*
926 * This thread manage the consumer error sent back to the session daemon.
927 */
928 static void *thread_manage_consumer(void *data)
929 {
930 int sock = -1, i, ret, pollfd;
931 uint32_t revents, nb_fd;
932 enum lttcomm_return_code code;
933 struct lttng_poll_event events;
934 struct consumer_data *consumer_data = data;
935
936 DBG("[thread] Manage consumer started");
937
938 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
939 if (ret < 0) {
940 goto error_listen;
941 }
942
943 /*
944 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
945 * Nothing more will be added to this poll set.
946 */
947 ret = create_thread_poll_set(&events, 2);
948 if (ret < 0) {
949 goto error_poll;
950 }
951
952 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
953 if (ret < 0) {
954 goto error;
955 }
956
957 nb_fd = LTTNG_POLL_GETNB(&events);
958
959 /* Inifinite blocking call, waiting for transmission */
960 restart:
961 ret = lttng_poll_wait(&events, -1);
962 if (ret < 0) {
963 /*
964 * Restart interrupted system call.
965 */
966 if (errno == EINTR) {
967 goto restart;
968 }
969 goto error;
970 }
971
972 for (i = 0; i < nb_fd; i++) {
973 /* Fetch once the poll data */
974 revents = LTTNG_POLL_GETEV(&events, i);
975 pollfd = LTTNG_POLL_GETFD(&events, i);
976
977 /* Thread quit pipe has been closed. Killing thread. */
978 ret = check_thread_quit_pipe(pollfd, revents);
979 if (ret) {
980 goto error;
981 }
982
983 /* Event on the registration socket */
984 if (pollfd == consumer_data->err_sock) {
985 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
986 ERR("consumer err socket poll error");
987 goto error;
988 }
989 }
990 }
991
992 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
993 if (sock < 0) {
994 goto error;
995 }
996
997 DBG2("Receiving code from consumer err_sock");
998
999 /* Getting status code from kconsumerd */
1000 ret = lttcomm_recv_unix_sock(sock, &code,
1001 sizeof(enum lttcomm_return_code));
1002 if (ret <= 0) {
1003 goto error;
1004 }
1005
1006 if (code == CONSUMERD_COMMAND_SOCK_READY) {
1007 consumer_data->cmd_sock =
1008 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
1009 if (consumer_data->cmd_sock < 0) {
1010 sem_post(&consumer_data->sem);
1011 PERROR("consumer connect");
1012 goto error;
1013 }
1014 /* Signal condition to tell that the kconsumerd is ready */
1015 sem_post(&consumer_data->sem);
1016 DBG("consumer command socket ready");
1017 } else {
1018 ERR("consumer error when waiting for SOCK_READY : %s",
1019 lttcomm_get_readable_code(-code));
1020 goto error;
1021 }
1022
1023 /* Remove the kconsumerd error sock since we've established a connexion */
1024 ret = lttng_poll_del(&events, consumer_data->err_sock);
1025 if (ret < 0) {
1026 goto error;
1027 }
1028
1029 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
1030 if (ret < 0) {
1031 goto error;
1032 }
1033
1034 /* Update number of fd */
1035 nb_fd = LTTNG_POLL_GETNB(&events);
1036
1037 /* Inifinite blocking call, waiting for transmission */
1038 restart_poll:
1039 ret = lttng_poll_wait(&events, -1);
1040 if (ret < 0) {
1041 /*
1042 * Restart interrupted system call.
1043 */
1044 if (errno == EINTR) {
1045 goto restart_poll;
1046 }
1047 goto error;
1048 }
1049
1050 for (i = 0; i < nb_fd; i++) {
1051 /* Fetch once the poll data */
1052 revents = LTTNG_POLL_GETEV(&events, i);
1053 pollfd = LTTNG_POLL_GETFD(&events, i);
1054
1055 /* Thread quit pipe has been closed. Killing thread. */
1056 ret = check_thread_quit_pipe(pollfd, revents);
1057 if (ret) {
1058 goto error;
1059 }
1060
1061 /* Event on the kconsumerd socket */
1062 if (pollfd == sock) {
1063 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1064 ERR("consumer err socket second poll error");
1065 goto error;
1066 }
1067 }
1068 }
1069
1070 /* Wait for any kconsumerd error */
1071 ret = lttcomm_recv_unix_sock(sock, &code,
1072 sizeof(enum lttcomm_return_code));
1073 if (ret <= 0) {
1074 ERR("consumer closed the command socket");
1075 goto error;
1076 }
1077
1078 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
1079
1080 error:
1081 if (consumer_data->err_sock >= 0) {
1082 ret = close(consumer_data->err_sock);
1083 if (ret) {
1084 PERROR("close");
1085 }
1086 }
1087 if (consumer_data->cmd_sock >= 0) {
1088 ret = close(consumer_data->cmd_sock);
1089 if (ret) {
1090 PERROR("close");
1091 }
1092 }
1093 if (sock >= 0) {
1094 ret = close(sock);
1095 if (ret) {
1096 PERROR("close");
1097 }
1098 }
1099
1100 unlink(consumer_data->err_unix_sock_path);
1101 unlink(consumer_data->cmd_unix_sock_path);
1102 consumer_data->pid = 0;
1103
1104 lttng_poll_clean(&events);
1105 error_poll:
1106 error_listen:
1107 DBG("consumer thread cleanup completed");
1108
1109 return NULL;
1110 }
1111
1112 /*
1113 * This thread manage application communication.
1114 */
1115 static void *thread_manage_apps(void *data)
1116 {
1117 int i, ret, pollfd;
1118 uint32_t revents, nb_fd;
1119 struct ust_command ust_cmd;
1120 struct lttng_poll_event events;
1121
1122 DBG("[thread] Manage application started");
1123
1124 rcu_register_thread();
1125 rcu_thread_online();
1126
1127 ret = create_thread_poll_set(&events, 2);
1128 if (ret < 0) {
1129 goto error_poll_create;
1130 }
1131
1132 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1133 if (ret < 0) {
1134 goto error;
1135 }
1136
1137 while (1) {
1138 /* Zeroed the events structure */
1139 lttng_poll_reset(&events);
1140
1141 nb_fd = LTTNG_POLL_GETNB(&events);
1142
1143 DBG("Apps thread polling on %d fds", nb_fd);
1144
1145 /* Inifinite blocking call, waiting for transmission */
1146 restart:
1147 ret = lttng_poll_wait(&events, -1);
1148 if (ret < 0) {
1149 /*
1150 * Restart interrupted system call.
1151 */
1152 if (errno == EINTR) {
1153 goto restart;
1154 }
1155 goto error;
1156 }
1157
1158 for (i = 0; i < nb_fd; i++) {
1159 /* Fetch once the poll data */
1160 revents = LTTNG_POLL_GETEV(&events, i);
1161 pollfd = LTTNG_POLL_GETFD(&events, i);
1162
1163 /* Thread quit pipe has been closed. Killing thread. */
1164 ret = check_thread_quit_pipe(pollfd, revents);
1165 if (ret) {
1166 goto error;
1167 }
1168
1169 /* Inspect the apps cmd pipe */
1170 if (pollfd == apps_cmd_pipe[0]) {
1171 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1172 ERR("Apps command pipe error");
1173 goto error;
1174 } else if (revents & LPOLLIN) {
1175 /* Empty pipe */
1176 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1177 if (ret < 0 || ret < sizeof(ust_cmd)) {
1178 PERROR("read apps cmd pipe");
1179 goto error;
1180 }
1181
1182 /* Register applicaton to the session daemon */
1183 ret = ust_app_register(&ust_cmd.reg_msg,
1184 ust_cmd.sock);
1185 if (ret == -ENOMEM) {
1186 goto error;
1187 } else if (ret < 0) {
1188 break;
1189 }
1190
1191 /*
1192 * Validate UST version compatibility.
1193 */
1194 ret = ust_app_validate_version(ust_cmd.sock);
1195 if (ret >= 0) {
1196 /*
1197 * Add channel(s) and event(s) to newly registered apps
1198 * from lttng global UST domain.
1199 */
1200 update_ust_app(ust_cmd.sock);
1201 }
1202
1203 ret = ust_app_register_done(ust_cmd.sock);
1204 if (ret < 0) {
1205 /*
1206 * If the registration is not possible, we simply
1207 * unregister the apps and continue
1208 */
1209 ust_app_unregister(ust_cmd.sock);
1210 } else {
1211 /*
1212 * We just need here to monitor the close of the UST
1213 * socket and poll set monitor those by default.
1214 * Listen on POLLIN (even if we never expect any
1215 * data) to ensure that hangup wakes us.
1216 */
1217 ret = lttng_poll_add(&events, ust_cmd.sock, LPOLLIN);
1218 if (ret < 0) {
1219 goto error;
1220 }
1221
1222 DBG("Apps with sock %d added to poll set",
1223 ust_cmd.sock);
1224 }
1225
1226 break;
1227 }
1228 } else {
1229 /*
1230 * At this point, we know that a registered application made
1231 * the event at poll_wait.
1232 */
1233 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1234 /* Removing from the poll set */
1235 ret = lttng_poll_del(&events, pollfd);
1236 if (ret < 0) {
1237 goto error;
1238 }
1239
1240 /* Socket closed on remote end. */
1241 ust_app_unregister(pollfd);
1242 break;
1243 }
1244 }
1245 }
1246 }
1247
1248 error:
1249 lttng_poll_clean(&events);
1250 error_poll_create:
1251 DBG("Application communication apps thread cleanup complete");
1252 rcu_thread_offline();
1253 rcu_unregister_thread();
1254 return NULL;
1255 }
1256
1257 /*
1258 * Dispatch request from the registration threads to the application
1259 * communication thread.
1260 */
1261 static void *thread_dispatch_ust_registration(void *data)
1262 {
1263 int ret;
1264 struct cds_wfq_node *node;
1265 struct ust_command *ust_cmd = NULL;
1266
1267 DBG("[thread] Dispatch UST command started");
1268
1269 while (!dispatch_thread_exit) {
1270 /* Atomically prepare the queue futex */
1271 futex_nto1_prepare(&ust_cmd_queue.futex);
1272
1273 do {
1274 /* Dequeue command for registration */
1275 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1276 if (node == NULL) {
1277 DBG("Woken up but nothing in the UST command queue");
1278 /* Continue thread execution */
1279 break;
1280 }
1281
1282 ust_cmd = caa_container_of(node, struct ust_command, node);
1283
1284 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1285 " gid:%d sock:%d name:%s (version %d.%d)",
1286 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1287 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1288 ust_cmd->sock, ust_cmd->reg_msg.name,
1289 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1290 /*
1291 * Inform apps thread of the new application registration. This
1292 * call is blocking so we can be assured that the data will be read
1293 * at some point in time or wait to the end of the world :)
1294 */
1295 ret = write(apps_cmd_pipe[1], ust_cmd,
1296 sizeof(struct ust_command));
1297 if (ret < 0) {
1298 PERROR("write apps cmd pipe");
1299 if (errno == EBADF) {
1300 /*
1301 * We can't inform the application thread to process
1302 * registration. We will exit or else application
1303 * registration will not occur and tracing will never
1304 * start.
1305 */
1306 goto error;
1307 }
1308 }
1309 free(ust_cmd);
1310 } while (node != NULL);
1311
1312 /* Futex wait on queue. Blocking call on futex() */
1313 futex_nto1_wait(&ust_cmd_queue.futex);
1314 }
1315
1316 error:
1317 DBG("Dispatch thread dying");
1318 return NULL;
1319 }
1320
1321 /*
1322 * This thread manage application registration.
1323 */
1324 static void *thread_registration_apps(void *data)
1325 {
1326 int sock = -1, i, ret, pollfd;
1327 uint32_t revents, nb_fd;
1328 struct lttng_poll_event events;
1329 /*
1330 * Get allocated in this thread, enqueued to a global queue, dequeued and
1331 * freed in the manage apps thread.
1332 */
1333 struct ust_command *ust_cmd = NULL;
1334
1335 DBG("[thread] Manage application registration started");
1336
1337 ret = lttcomm_listen_unix_sock(apps_sock);
1338 if (ret < 0) {
1339 goto error_listen;
1340 }
1341
1342 /*
1343 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1344 * more will be added to this poll set.
1345 */
1346 ret = create_thread_poll_set(&events, 2);
1347 if (ret < 0) {
1348 goto error_create_poll;
1349 }
1350
1351 /* Add the application registration socket */
1352 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1353 if (ret < 0) {
1354 goto error_poll_add;
1355 }
1356
1357 /* Notify all applications to register */
1358 ret = notify_ust_apps(1);
1359 if (ret < 0) {
1360 ERR("Failed to notify applications or create the wait shared memory.\n"
1361 "Execution continues but there might be problem for already\n"
1362 "running applications that wishes to register.");
1363 }
1364
1365 while (1) {
1366 DBG("Accepting application registration");
1367
1368 nb_fd = LTTNG_POLL_GETNB(&events);
1369
1370 /* Inifinite blocking call, waiting for transmission */
1371 restart:
1372 ret = lttng_poll_wait(&events, -1);
1373 if (ret < 0) {
1374 /*
1375 * Restart interrupted system call.
1376 */
1377 if (errno == EINTR) {
1378 goto restart;
1379 }
1380 goto error;
1381 }
1382
1383 for (i = 0; i < nb_fd; i++) {
1384 /* Fetch once the poll data */
1385 revents = LTTNG_POLL_GETEV(&events, i);
1386 pollfd = LTTNG_POLL_GETFD(&events, i);
1387
1388 /* Thread quit pipe has been closed. Killing thread. */
1389 ret = check_thread_quit_pipe(pollfd, revents);
1390 if (ret) {
1391 goto error;
1392 }
1393
1394 /* Event on the registration socket */
1395 if (pollfd == apps_sock) {
1396 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1397 ERR("Register apps socket poll error");
1398 goto error;
1399 } else if (revents & LPOLLIN) {
1400 sock = lttcomm_accept_unix_sock(apps_sock);
1401 if (sock < 0) {
1402 goto error;
1403 }
1404
1405 /* Create UST registration command for enqueuing */
1406 ust_cmd = zmalloc(sizeof(struct ust_command));
1407 if (ust_cmd == NULL) {
1408 PERROR("ust command zmalloc");
1409 goto error;
1410 }
1411
1412 /*
1413 * Using message-based transmissions to ensure we don't
1414 * have to deal with partially received messages.
1415 */
1416 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1417 sizeof(struct ust_register_msg));
1418 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1419 if (ret < 0) {
1420 PERROR("lttcomm_recv_unix_sock register apps");
1421 } else {
1422 ERR("Wrong size received on apps register");
1423 }
1424 free(ust_cmd);
1425 ret = close(sock);
1426 if (ret) {
1427 PERROR("close");
1428 }
1429 sock = -1;
1430 continue;
1431 }
1432
1433 ust_cmd->sock = sock;
1434
1435 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1436 " gid:%d sock:%d name:%s (version %d.%d)",
1437 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1438 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1439 ust_cmd->sock, ust_cmd->reg_msg.name,
1440 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1441
1442 /*
1443 * Lock free enqueue the registration request. The red pill
1444 * has been taken! This apps will be part of the *system*.
1445 */
1446 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1447
1448 /*
1449 * Wake the registration queue futex. Implicit memory
1450 * barrier with the exchange in cds_wfq_enqueue.
1451 */
1452 futex_nto1_wake(&ust_cmd_queue.futex);
1453 }
1454 }
1455 }
1456 }
1457
1458 error:
1459 /* Notify that the registration thread is gone */
1460 notify_ust_apps(0);
1461
1462 if (apps_sock >= 0) {
1463 ret = close(apps_sock);
1464 if (ret) {
1465 PERROR("close");
1466 }
1467 }
1468 if (sock >= 0) {
1469 ret = close(sock);
1470 if (ret) {
1471 PERROR("close");
1472 }
1473 }
1474 unlink(apps_unix_sock_path);
1475
1476 error_poll_add:
1477 lttng_poll_clean(&events);
1478 error_listen:
1479 error_create_poll:
1480 DBG("UST Registration thread cleanup complete");
1481
1482 return NULL;
1483 }
1484
1485 /*
1486 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1487 * exec or it will fails.
1488 */
1489 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1490 {
1491 int ret;
1492 struct timespec timeout;
1493
1494 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1495 timeout.tv_nsec = 0;
1496
1497 /* Setup semaphore */
1498 ret = sem_init(&consumer_data->sem, 0, 0);
1499 if (ret < 0) {
1500 PERROR("sem_init consumer semaphore");
1501 goto error;
1502 }
1503
1504 ret = pthread_create(&consumer_data->thread, NULL,
1505 thread_manage_consumer, consumer_data);
1506 if (ret != 0) {
1507 PERROR("pthread_create consumer");
1508 ret = -1;
1509 goto error;
1510 }
1511
1512 /* Get time for sem_timedwait absolute timeout */
1513 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1514 if (ret < 0) {
1515 PERROR("clock_gettime spawn consumer");
1516 /* Infinite wait for the kconsumerd thread to be ready */
1517 ret = sem_wait(&consumer_data->sem);
1518 } else {
1519 /* Normal timeout if the gettime was successful */
1520 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1521 ret = sem_timedwait(&consumer_data->sem, &timeout);
1522 }
1523
1524 if (ret < 0) {
1525 if (errno == ETIMEDOUT) {
1526 /*
1527 * Call has timed out so we kill the kconsumerd_thread and return
1528 * an error.
1529 */
1530 ERR("The consumer thread was never ready. Killing it");
1531 ret = pthread_cancel(consumer_data->thread);
1532 if (ret < 0) {
1533 PERROR("pthread_cancel consumer thread");
1534 }
1535 } else {
1536 PERROR("semaphore wait failed consumer thread");
1537 }
1538 goto error;
1539 }
1540
1541 pthread_mutex_lock(&consumer_data->pid_mutex);
1542 if (consumer_data->pid == 0) {
1543 ERR("Kconsumerd did not start");
1544 pthread_mutex_unlock(&consumer_data->pid_mutex);
1545 goto error;
1546 }
1547 pthread_mutex_unlock(&consumer_data->pid_mutex);
1548
1549 return 0;
1550
1551 error:
1552 return ret;
1553 }
1554
1555 /*
1556 * Join consumer thread
1557 */
1558 static int join_consumer_thread(struct consumer_data *consumer_data)
1559 {
1560 void *status;
1561 int ret;
1562
1563 if (consumer_data->pid != 0) {
1564 ret = kill(consumer_data->pid, SIGTERM);
1565 if (ret) {
1566 ERR("Error killing consumer daemon");
1567 return ret;
1568 }
1569 return pthread_join(consumer_data->thread, &status);
1570 } else {
1571 return 0;
1572 }
1573 }
1574
1575 /*
1576 * Fork and exec a consumer daemon (consumerd).
1577 *
1578 * Return pid if successful else -1.
1579 */
1580 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1581 {
1582 int ret;
1583 pid_t pid;
1584 const char *consumer_to_use;
1585 const char *verbosity;
1586 struct stat st;
1587
1588 DBG("Spawning consumerd");
1589
1590 pid = fork();
1591 if (pid == 0) {
1592 /*
1593 * Exec consumerd.
1594 */
1595 if (opt_verbose_consumer) {
1596 verbosity = "--verbose";
1597 } else {
1598 verbosity = "--quiet";
1599 }
1600 switch (consumer_data->type) {
1601 case LTTNG_CONSUMER_KERNEL:
1602 /*
1603 * Find out which consumerd to execute. We will first try the
1604 * 64-bit path, then the sessiond's installation directory, and
1605 * fallback on the 32-bit one,
1606 */
1607 DBG3("Looking for a kernel consumer at these locations:");
1608 DBG3(" 1) %s", consumerd64_bin);
1609 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, CONSUMERD_FILE);
1610 DBG3(" 3) %s", consumerd32_bin);
1611 if (stat(consumerd64_bin, &st) == 0) {
1612 DBG3("Found location #1");
1613 consumer_to_use = consumerd64_bin;
1614 } else if (stat(INSTALL_BIN_PATH "/" CONSUMERD_FILE, &st) == 0) {
1615 DBG3("Found location #2");
1616 consumer_to_use = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
1617 } else if (stat(consumerd32_bin, &st) == 0) {
1618 DBG3("Found location #3");
1619 consumer_to_use = consumerd32_bin;
1620 } else {
1621 DBG("Could not find any valid consumerd executable");
1622 break;
1623 }
1624 DBG("Using kernel consumer at: %s", consumer_to_use);
1625 execl(consumer_to_use,
1626 "lttng-consumerd", verbosity, "-k",
1627 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1628 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1629 NULL);
1630 break;
1631 case LTTNG_CONSUMER64_UST:
1632 {
1633 char *tmpnew = NULL;
1634
1635 if (consumerd64_libdir[0] != '\0') {
1636 char *tmp;
1637 size_t tmplen;
1638
1639 tmp = getenv("LD_LIBRARY_PATH");
1640 if (!tmp) {
1641 tmp = "";
1642 }
1643 tmplen = strlen("LD_LIBRARY_PATH=")
1644 + strlen(consumerd64_libdir) + 1 /* : */ + strlen(tmp);
1645 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1646 if (!tmpnew) {
1647 ret = -ENOMEM;
1648 goto error;
1649 }
1650 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1651 strcat(tmpnew, consumerd64_libdir);
1652 if (tmp[0] != '\0') {
1653 strcat(tmpnew, ":");
1654 strcat(tmpnew, tmp);
1655 }
1656 ret = putenv(tmpnew);
1657 if (ret) {
1658 ret = -errno;
1659 goto error;
1660 }
1661 }
1662 DBG("Using 64-bit UST consumer at: %s", consumerd64_bin);
1663 ret = execl(consumerd64_bin, "lttng-consumerd", verbosity, "-u",
1664 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1665 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1666 NULL);
1667 if (consumerd64_libdir[0] != '\0') {
1668 free(tmpnew);
1669 }
1670 if (ret) {
1671 goto error;
1672 }
1673 break;
1674 }
1675 case LTTNG_CONSUMER32_UST:
1676 {
1677 char *tmpnew = NULL;
1678
1679 if (consumerd32_libdir[0] != '\0') {
1680 char *tmp;
1681 size_t tmplen;
1682
1683 tmp = getenv("LD_LIBRARY_PATH");
1684 if (!tmp) {
1685 tmp = "";
1686 }
1687 tmplen = strlen("LD_LIBRARY_PATH=")
1688 + strlen(consumerd32_libdir) + 1 /* : */ + strlen(tmp);
1689 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1690 if (!tmpnew) {
1691 ret = -ENOMEM;
1692 goto error;
1693 }
1694 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1695 strcat(tmpnew, consumerd32_libdir);
1696 if (tmp[0] != '\0') {
1697 strcat(tmpnew, ":");
1698 strcat(tmpnew, tmp);
1699 }
1700 ret = putenv(tmpnew);
1701 if (ret) {
1702 ret = -errno;
1703 goto error;
1704 }
1705 }
1706 DBG("Using 32-bit UST consumer at: %s", consumerd32_bin);
1707 ret = execl(consumerd32_bin, "lttng-consumerd", verbosity, "-u",
1708 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1709 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1710 NULL);
1711 if (consumerd32_libdir[0] != '\0') {
1712 free(tmpnew);
1713 }
1714 if (ret) {
1715 goto error;
1716 }
1717 break;
1718 }
1719 default:
1720 PERROR("unknown consumer type");
1721 exit(EXIT_FAILURE);
1722 }
1723 if (errno != 0) {
1724 PERROR("kernel start consumer exec");
1725 }
1726 exit(EXIT_FAILURE);
1727 } else if (pid > 0) {
1728 ret = pid;
1729 } else {
1730 PERROR("start consumer fork");
1731 ret = -errno;
1732 }
1733 error:
1734 return ret;
1735 }
1736
1737 /*
1738 * Spawn the consumerd daemon and session daemon thread.
1739 */
1740 static int start_consumerd(struct consumer_data *consumer_data)
1741 {
1742 int ret;
1743
1744 pthread_mutex_lock(&consumer_data->pid_mutex);
1745 if (consumer_data->pid != 0) {
1746 pthread_mutex_unlock(&consumer_data->pid_mutex);
1747 goto end;
1748 }
1749
1750 ret = spawn_consumerd(consumer_data);
1751 if (ret < 0) {
1752 ERR("Spawning consumerd failed");
1753 pthread_mutex_unlock(&consumer_data->pid_mutex);
1754 goto error;
1755 }
1756
1757 /* Setting up the consumer_data pid */
1758 consumer_data->pid = ret;
1759 DBG2("Consumer pid %d", consumer_data->pid);
1760 pthread_mutex_unlock(&consumer_data->pid_mutex);
1761
1762 DBG2("Spawning consumer control thread");
1763 ret = spawn_consumer_thread(consumer_data);
1764 if (ret < 0) {
1765 ERR("Fatal error spawning consumer control thread");
1766 goto error;
1767 }
1768
1769 end:
1770 return 0;
1771
1772 error:
1773 return ret;
1774 }
1775
1776 /*
1777 * Check version of the lttng-modules.
1778 */
1779 static int validate_lttng_modules_version(void)
1780 {
1781 return kernel_validate_version(kernel_tracer_fd);
1782 }
1783
1784 /*
1785 * Setup necessary data for kernel tracer action.
1786 */
1787 static int init_kernel_tracer(void)
1788 {
1789 int ret;
1790
1791 /* Modprobe lttng kernel modules */
1792 ret = modprobe_lttng_control();
1793 if (ret < 0) {
1794 goto error;
1795 }
1796
1797 /* Open debugfs lttng */
1798 kernel_tracer_fd = open(module_proc_lttng, O_RDWR);
1799 if (kernel_tracer_fd < 0) {
1800 DBG("Failed to open %s", module_proc_lttng);
1801 ret = -1;
1802 goto error_open;
1803 }
1804
1805 /* Validate kernel version */
1806 ret = validate_lttng_modules_version();
1807 if (ret < 0) {
1808 goto error_version;
1809 }
1810
1811 ret = modprobe_lttng_data();
1812 if (ret < 0) {
1813 goto error_modules;
1814 }
1815
1816 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1817 return 0;
1818
1819 error_version:
1820 modprobe_remove_lttng_control();
1821 ret = close(kernel_tracer_fd);
1822 if (ret) {
1823 PERROR("close");
1824 }
1825 kernel_tracer_fd = -1;
1826 return LTTCOMM_KERN_VERSION;
1827
1828 error_modules:
1829 ret = close(kernel_tracer_fd);
1830 if (ret) {
1831 PERROR("close");
1832 }
1833
1834 error_open:
1835 modprobe_remove_lttng_control();
1836
1837 error:
1838 WARN("No kernel tracer available");
1839 kernel_tracer_fd = -1;
1840 return LTTCOMM_KERN_NA;
1841 }
1842
1843 /*
1844 * Init tracing by creating trace directory and sending fds kernel consumer.
1845 */
1846 static int init_kernel_tracing(struct ltt_kernel_session *session)
1847 {
1848 int ret = 0;
1849
1850 if (session->consumer_fds_sent == 0) {
1851 /*
1852 * Assign default kernel consumer socket if no consumer assigned to the
1853 * kernel session. At this point, it's NOT suppose to be 0 but this is
1854 * an extra security check.
1855 */
1856 if (session->consumer_fd == 0) {
1857 session->consumer_fd = kconsumer_data.cmd_sock;
1858 }
1859
1860 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1861 if (ret < 0) {
1862 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1863 goto error;
1864 }
1865
1866 session->consumer_fds_sent = 1;
1867 }
1868
1869 error:
1870 return ret;
1871 }
1872
1873 /*
1874 * Create an UST session and add it to the session ust list.
1875 */
1876 static int create_ust_session(struct ltt_session *session,
1877 struct lttng_domain *domain)
1878 {
1879 struct ltt_ust_session *lus = NULL;
1880 int ret;
1881
1882 switch (domain->type) {
1883 case LTTNG_DOMAIN_UST:
1884 break;
1885 default:
1886 ret = LTTCOMM_UNKNOWN_DOMAIN;
1887 goto error;
1888 }
1889
1890 DBG("Creating UST session");
1891
1892 lus = trace_ust_create_session(session->path, session->id, domain);
1893 if (lus == NULL) {
1894 ret = LTTCOMM_UST_SESS_FAIL;
1895 goto error;
1896 }
1897
1898 ret = run_as_mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1899 session->uid, session->gid);
1900 if (ret < 0) {
1901 if (ret != -EEXIST) {
1902 ERR("Trace directory creation error");
1903 ret = LTTCOMM_UST_SESS_FAIL;
1904 goto error;
1905 }
1906 }
1907
1908 /* The domain type dictate different actions on session creation */
1909 switch (domain->type) {
1910 case LTTNG_DOMAIN_UST:
1911 /* No ustctl for the global UST domain */
1912 break;
1913 default:
1914 ERR("Unknown UST domain on create session %d", domain->type);
1915 goto error;
1916 }
1917 lus->uid = session->uid;
1918 lus->gid = session->gid;
1919 session->ust_session = lus;
1920
1921 return LTTCOMM_OK;
1922
1923 error:
1924 free(lus);
1925 return ret;
1926 }
1927
1928 /*
1929 * Create a kernel tracer session then create the default channel.
1930 */
1931 static int create_kernel_session(struct ltt_session *session)
1932 {
1933 int ret;
1934
1935 DBG("Creating kernel session");
1936
1937 ret = kernel_create_session(session, kernel_tracer_fd);
1938 if (ret < 0) {
1939 ret = LTTCOMM_KERN_SESS_FAIL;
1940 goto error;
1941 }
1942
1943 /* Set kernel consumer socket fd */
1944 if (kconsumer_data.cmd_sock) {
1945 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1946 }
1947
1948 ret = run_as_mkdir_recursive(session->kernel_session->trace_path,
1949 S_IRWXU | S_IRWXG, session->uid, session->gid);
1950 if (ret < 0) {
1951 if (ret != -EEXIST) {
1952 ERR("Trace directory creation error");
1953 goto error;
1954 }
1955 }
1956 session->kernel_session->uid = session->uid;
1957 session->kernel_session->gid = session->gid;
1958
1959 error:
1960 return ret;
1961 }
1962
1963 /*
1964 * Check if the UID or GID match the session. Root user has access to all
1965 * sessions.
1966 */
1967 static int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
1968 {
1969 if (uid != session->uid && gid != session->gid && uid != 0) {
1970 return 0;
1971 } else {
1972 return 1;
1973 }
1974 }
1975
1976 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
1977 {
1978 unsigned int i = 0;
1979 struct ltt_session *session;
1980
1981 DBG("Counting number of available session for UID %d GID %d",
1982 uid, gid);
1983 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1984 /*
1985 * Only list the sessions the user can control.
1986 */
1987 if (!session_access_ok(session, uid, gid)) {
1988 continue;
1989 }
1990 i++;
1991 }
1992 return i;
1993 }
1994
1995 /*
1996 * Using the session list, filled a lttng_session array to send back to the
1997 * client for session listing.
1998 *
1999 * The session list lock MUST be acquired before calling this function. Use
2000 * session_lock_list() and session_unlock_list().
2001 */
2002 static void list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2003 gid_t gid)
2004 {
2005 unsigned int i = 0;
2006 struct ltt_session *session;
2007
2008 DBG("Getting all available session for UID %d GID %d",
2009 uid, gid);
2010 /*
2011 * Iterate over session list and append data after the control struct in
2012 * the buffer.
2013 */
2014 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
2015 /*
2016 * Only list the sessions the user can control.
2017 */
2018 if (!session_access_ok(session, uid, gid)) {
2019 continue;
2020 }
2021 strncpy(sessions[i].path, session->path, PATH_MAX);
2022 sessions[i].path[PATH_MAX - 1] = '\0';
2023 strncpy(sessions[i].name, session->name, NAME_MAX);
2024 sessions[i].name[NAME_MAX - 1] = '\0';
2025 sessions[i].enabled = session->enabled;
2026 i++;
2027 }
2028 }
2029
2030 /*
2031 * Fill lttng_channel array of all channels.
2032 */
2033 static void list_lttng_channels(int domain, struct ltt_session *session,
2034 struct lttng_channel *channels)
2035 {
2036 int i = 0;
2037 struct ltt_kernel_channel *kchan;
2038
2039 DBG("Listing channels for session %s", session->name);
2040
2041 switch (domain) {
2042 case LTTNG_DOMAIN_KERNEL:
2043 /* Kernel channels */
2044 if (session->kernel_session != NULL) {
2045 cds_list_for_each_entry(kchan,
2046 &session->kernel_session->channel_list.head, list) {
2047 /* Copy lttng_channel struct to array */
2048 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
2049 channels[i].enabled = kchan->enabled;
2050 i++;
2051 }
2052 }
2053 break;
2054 case LTTNG_DOMAIN_UST:
2055 {
2056 struct lttng_ht_iter iter;
2057 struct ltt_ust_channel *uchan;
2058
2059 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
2060 &iter.iter, uchan, node.node) {
2061 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
2062 channels[i].attr.overwrite = uchan->attr.overwrite;
2063 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
2064 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
2065 channels[i].attr.switch_timer_interval =
2066 uchan->attr.switch_timer_interval;
2067 channels[i].attr.read_timer_interval =
2068 uchan->attr.read_timer_interval;
2069 channels[i].enabled = uchan->enabled;
2070 switch (uchan->attr.output) {
2071 case LTTNG_UST_MMAP:
2072 default:
2073 channels[i].attr.output = LTTNG_EVENT_MMAP;
2074 break;
2075 }
2076 i++;
2077 }
2078 break;
2079 }
2080 default:
2081 break;
2082 }
2083 }
2084
2085 /*
2086 * Create a list of ust global domain events.
2087 */
2088 static int list_lttng_ust_global_events(char *channel_name,
2089 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
2090 {
2091 int i = 0, ret = 0;
2092 unsigned int nb_event = 0;
2093 struct lttng_ht_iter iter;
2094 struct lttng_ht_node_str *node;
2095 struct ltt_ust_channel *uchan;
2096 struct ltt_ust_event *uevent;
2097 struct lttng_event *tmp;
2098
2099 DBG("Listing UST global events for channel %s", channel_name);
2100
2101 rcu_read_lock();
2102
2103 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
2104 node = lttng_ht_iter_get_node_str(&iter);
2105 if (node == NULL) {
2106 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
2107 goto error;
2108 }
2109
2110 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
2111
2112 nb_event += lttng_ht_get_count(uchan->events);
2113
2114 if (nb_event == 0) {
2115 ret = nb_event;
2116 goto error;
2117 }
2118
2119 DBG3("Listing UST global %d events", nb_event);
2120
2121 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
2122 if (tmp == NULL) {
2123 ret = -LTTCOMM_FATAL;
2124 goto error;
2125 }
2126
2127 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
2128 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
2129 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2130 tmp[i].enabled = uevent->enabled;
2131 switch (uevent->attr.instrumentation) {
2132 case LTTNG_UST_TRACEPOINT:
2133 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
2134 break;
2135 case LTTNG_UST_PROBE:
2136 tmp[i].type = LTTNG_EVENT_PROBE;
2137 break;
2138 case LTTNG_UST_FUNCTION:
2139 tmp[i].type = LTTNG_EVENT_FUNCTION;
2140 break;
2141 }
2142 tmp[i].loglevel = uevent->attr.loglevel;
2143 switch (uevent->attr.loglevel_type) {
2144 case LTTNG_UST_LOGLEVEL_ALL:
2145 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2146 break;
2147 case LTTNG_UST_LOGLEVEL_RANGE:
2148 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
2149 break;
2150 case LTTNG_UST_LOGLEVEL_SINGLE:
2151 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
2152 break;
2153 }
2154 i++;
2155 }
2156
2157 ret = nb_event;
2158 *events = tmp;
2159
2160 error:
2161 rcu_read_unlock();
2162 return ret;
2163 }
2164
2165 /*
2166 * Fill lttng_event array of all kernel events in the channel.
2167 */
2168 static int list_lttng_kernel_events(char *channel_name,
2169 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
2170 {
2171 int i = 0, ret;
2172 unsigned int nb_event;
2173 struct ltt_kernel_event *event;
2174 struct ltt_kernel_channel *kchan;
2175
2176 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
2177 if (kchan == NULL) {
2178 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2179 goto error;
2180 }
2181
2182 nb_event = kchan->event_count;
2183
2184 DBG("Listing events for channel %s", kchan->channel->name);
2185
2186 if (nb_event == 0) {
2187 ret = nb_event;
2188 goto error;
2189 }
2190
2191 *events = zmalloc(nb_event * sizeof(struct lttng_event));
2192 if (*events == NULL) {
2193 ret = LTTCOMM_FATAL;
2194 goto error;
2195 }
2196
2197 /* Kernel channels */
2198 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
2199 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
2200 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2201 (*events)[i].enabled = event->enabled;
2202 switch (event->event->instrumentation) {
2203 case LTTNG_KERNEL_TRACEPOINT:
2204 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
2205 break;
2206 case LTTNG_KERNEL_KPROBE:
2207 case LTTNG_KERNEL_KRETPROBE:
2208 (*events)[i].type = LTTNG_EVENT_PROBE;
2209 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
2210 sizeof(struct lttng_kernel_kprobe));
2211 break;
2212 case LTTNG_KERNEL_FUNCTION:
2213 (*events)[i].type = LTTNG_EVENT_FUNCTION;
2214 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
2215 sizeof(struct lttng_kernel_function));
2216 break;
2217 case LTTNG_KERNEL_NOOP:
2218 (*events)[i].type = LTTNG_EVENT_NOOP;
2219 break;
2220 case LTTNG_KERNEL_SYSCALL:
2221 (*events)[i].type = LTTNG_EVENT_SYSCALL;
2222 break;
2223 case LTTNG_KERNEL_ALL:
2224 assert(0);
2225 break;
2226 }
2227 i++;
2228 }
2229
2230 return nb_event;
2231
2232 error:
2233 return ret;
2234 }
2235
2236 /*
2237 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2238 */
2239 static int cmd_disable_channel(struct ltt_session *session,
2240 int domain, char *channel_name)
2241 {
2242 int ret;
2243 struct ltt_ust_session *usess;
2244
2245 usess = session->ust_session;
2246
2247 switch (domain) {
2248 case LTTNG_DOMAIN_KERNEL:
2249 {
2250 ret = channel_kernel_disable(session->kernel_session,
2251 channel_name);
2252 if (ret != LTTCOMM_OK) {
2253 goto error;
2254 }
2255
2256 kernel_wait_quiescent(kernel_tracer_fd);
2257 break;
2258 }
2259 case LTTNG_DOMAIN_UST:
2260 {
2261 struct ltt_ust_channel *uchan;
2262 struct lttng_ht *chan_ht;
2263
2264 chan_ht = usess->domain_global.channels;
2265
2266 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
2267 if (uchan == NULL) {
2268 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2269 goto error;
2270 }
2271
2272 ret = channel_ust_disable(usess, domain, uchan);
2273 if (ret != LTTCOMM_OK) {
2274 goto error;
2275 }
2276 break;
2277 }
2278 #if 0
2279 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2280 case LTTNG_DOMAIN_UST_EXEC_NAME:
2281 case LTTNG_DOMAIN_UST_PID:
2282 #endif
2283 default:
2284 ret = LTTCOMM_UNKNOWN_DOMAIN;
2285 goto error;
2286 }
2287
2288 ret = LTTCOMM_OK;
2289
2290 error:
2291 return ret;
2292 }
2293
2294 /*
2295 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2296 */
2297 static int cmd_enable_channel(struct ltt_session *session,
2298 int domain, struct lttng_channel *attr)
2299 {
2300 int ret;
2301 struct ltt_ust_session *usess = session->ust_session;
2302 struct lttng_ht *chan_ht;
2303
2304 DBG("Enabling channel %s for session %s", attr->name, session->name);
2305
2306 switch (domain) {
2307 case LTTNG_DOMAIN_KERNEL:
2308 {
2309 struct ltt_kernel_channel *kchan;
2310
2311 kchan = trace_kernel_get_channel_by_name(attr->name,
2312 session->kernel_session);
2313 if (kchan == NULL) {
2314 ret = channel_kernel_create(session->kernel_session,
2315 attr, kernel_poll_pipe[1]);
2316 } else {
2317 ret = channel_kernel_enable(session->kernel_session, kchan);
2318 }
2319
2320 if (ret != LTTCOMM_OK) {
2321 goto error;
2322 }
2323
2324 kernel_wait_quiescent(kernel_tracer_fd);
2325 break;
2326 }
2327 case LTTNG_DOMAIN_UST:
2328 {
2329 struct ltt_ust_channel *uchan;
2330
2331 chan_ht = usess->domain_global.channels;
2332
2333 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
2334 if (uchan == NULL) {
2335 ret = channel_ust_create(usess, domain, attr);
2336 } else {
2337 ret = channel_ust_enable(usess, domain, uchan);
2338 }
2339 break;
2340 }
2341 #if 0
2342 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2343 case LTTNG_DOMAIN_UST_EXEC_NAME:
2344 case LTTNG_DOMAIN_UST_PID:
2345 #endif
2346 default:
2347 ret = LTTCOMM_UNKNOWN_DOMAIN;
2348 goto error;
2349 }
2350
2351 error:
2352 return ret;
2353 }
2354
2355 /*
2356 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2357 */
2358 static int cmd_disable_event(struct ltt_session *session, int domain,
2359 char *channel_name, char *event_name)
2360 {
2361 int ret;
2362
2363 switch (domain) {
2364 case LTTNG_DOMAIN_KERNEL:
2365 {
2366 struct ltt_kernel_channel *kchan;
2367 struct ltt_kernel_session *ksess;
2368
2369 ksess = session->kernel_session;
2370
2371 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2372 if (kchan == NULL) {
2373 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2374 goto error;
2375 }
2376
2377 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
2378 if (ret != LTTCOMM_OK) {
2379 goto error;
2380 }
2381
2382 kernel_wait_quiescent(kernel_tracer_fd);
2383 break;
2384 }
2385 case LTTNG_DOMAIN_UST:
2386 {
2387 struct ltt_ust_channel *uchan;
2388 struct ltt_ust_session *usess;
2389
2390 usess = session->ust_session;
2391
2392 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2393 channel_name);
2394 if (uchan == NULL) {
2395 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2396 goto error;
2397 }
2398
2399 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
2400 if (ret != LTTCOMM_OK) {
2401 goto error;
2402 }
2403
2404 DBG3("Disable UST event %s in channel %s completed", event_name,
2405 channel_name);
2406 break;
2407 }
2408 #if 0
2409 case LTTNG_DOMAIN_UST_EXEC_NAME:
2410 case LTTNG_DOMAIN_UST_PID:
2411 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2412 #endif
2413 default:
2414 ret = LTTCOMM_UND;
2415 goto error;
2416 }
2417
2418 ret = LTTCOMM_OK;
2419
2420 error:
2421 return ret;
2422 }
2423
2424 /*
2425 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2426 */
2427 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2428 char *channel_name)
2429 {
2430 int ret;
2431
2432 switch (domain) {
2433 case LTTNG_DOMAIN_KERNEL:
2434 {
2435 struct ltt_kernel_session *ksess;
2436 struct ltt_kernel_channel *kchan;
2437
2438 ksess = session->kernel_session;
2439
2440 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2441 if (kchan == NULL) {
2442 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2443 goto error;
2444 }
2445
2446 ret = event_kernel_disable_all(ksess, kchan);
2447 if (ret != LTTCOMM_OK) {
2448 goto error;
2449 }
2450
2451 kernel_wait_quiescent(kernel_tracer_fd);
2452 break;
2453 }
2454 case LTTNG_DOMAIN_UST:
2455 {
2456 struct ltt_ust_session *usess;
2457 struct ltt_ust_channel *uchan;
2458
2459 usess = session->ust_session;
2460
2461 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2462 channel_name);
2463 if (uchan == NULL) {
2464 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2465 goto error;
2466 }
2467
2468 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
2469 if (ret != 0) {
2470 goto error;
2471 }
2472
2473 DBG3("Disable all UST events in channel %s completed", channel_name);
2474
2475 break;
2476 }
2477 #if 0
2478 case LTTNG_DOMAIN_UST_EXEC_NAME:
2479 case LTTNG_DOMAIN_UST_PID:
2480 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2481 #endif
2482 default:
2483 ret = LTTCOMM_UND;
2484 goto error;
2485 }
2486
2487 ret = LTTCOMM_OK;
2488
2489 error:
2490 return ret;
2491 }
2492
2493 /*
2494 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2495 */
2496 static int cmd_add_context(struct ltt_session *session, int domain,
2497 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2498 {
2499 int ret;
2500
2501 switch (domain) {
2502 case LTTNG_DOMAIN_KERNEL:
2503 /* Add kernel context to kernel tracer */
2504 ret = context_kernel_add(session->kernel_session, ctx,
2505 event_name, channel_name);
2506 if (ret != LTTCOMM_OK) {
2507 goto error;
2508 }
2509 break;
2510 case LTTNG_DOMAIN_UST:
2511 {
2512 struct ltt_ust_session *usess = session->ust_session;
2513
2514 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
2515 if (ret != LTTCOMM_OK) {
2516 goto error;
2517 }
2518 break;
2519 }
2520 #if 0
2521 case LTTNG_DOMAIN_UST_EXEC_NAME:
2522 case LTTNG_DOMAIN_UST_PID:
2523 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2524 #endif
2525 default:
2526 ret = LTTCOMM_UND;
2527 goto error;
2528 }
2529
2530 ret = LTTCOMM_OK;
2531
2532 error:
2533 return ret;
2534 }
2535
2536 /*
2537 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2538 */
2539 static int cmd_enable_event(struct ltt_session *session, int domain,
2540 char *channel_name, struct lttng_event *event)
2541 {
2542 int ret;
2543 struct lttng_channel *attr;
2544 struct ltt_ust_session *usess = session->ust_session;
2545
2546 switch (domain) {
2547 case LTTNG_DOMAIN_KERNEL:
2548 {
2549 struct ltt_kernel_channel *kchan;
2550
2551 kchan = trace_kernel_get_channel_by_name(channel_name,
2552 session->kernel_session);
2553 if (kchan == NULL) {
2554 attr = channel_new_default_attr(domain);
2555 if (attr == NULL) {
2556 ret = LTTCOMM_FATAL;
2557 goto error;
2558 }
2559 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2560
2561 /* This call will notify the kernel thread */
2562 ret = channel_kernel_create(session->kernel_session,
2563 attr, kernel_poll_pipe[1]);
2564 if (ret != LTTCOMM_OK) {
2565 free(attr);
2566 goto error;
2567 }
2568 free(attr);
2569 }
2570
2571 /* Get the newly created kernel channel pointer */
2572 kchan = trace_kernel_get_channel_by_name(channel_name,
2573 session->kernel_session);
2574 if (kchan == NULL) {
2575 /* This sould not happen... */
2576 ret = LTTCOMM_FATAL;
2577 goto error;
2578 }
2579
2580 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2581 event);
2582 if (ret != LTTCOMM_OK) {
2583 goto error;
2584 }
2585
2586 kernel_wait_quiescent(kernel_tracer_fd);
2587 break;
2588 }
2589 case LTTNG_DOMAIN_UST:
2590 {
2591 struct lttng_channel *attr;
2592 struct ltt_ust_channel *uchan;
2593
2594 /* Get channel from global UST domain */
2595 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2596 channel_name);
2597 if (uchan == NULL) {
2598 /* Create default channel */
2599 attr = channel_new_default_attr(domain);
2600 if (attr == NULL) {
2601 ret = LTTCOMM_FATAL;
2602 goto error;
2603 }
2604 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2605 attr->name[NAME_MAX - 1] = '\0';
2606
2607 ret = channel_ust_create(usess, domain, attr);
2608 if (ret != LTTCOMM_OK) {
2609 free(attr);
2610 goto error;
2611 }
2612 free(attr);
2613
2614 /* Get the newly created channel reference back */
2615 uchan = trace_ust_find_channel_by_name(
2616 usess->domain_global.channels, channel_name);
2617 if (uchan == NULL) {
2618 /* Something is really wrong */
2619 ret = LTTCOMM_FATAL;
2620 goto error;
2621 }
2622 }
2623
2624 /* At this point, the session and channel exist on the tracer */
2625 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
2626 if (ret != LTTCOMM_OK) {
2627 goto error;
2628 }
2629 break;
2630 }
2631 #if 0
2632 case LTTNG_DOMAIN_UST_EXEC_NAME:
2633 case LTTNG_DOMAIN_UST_PID:
2634 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2635 #endif
2636 default:
2637 ret = LTTCOMM_UND;
2638 goto error;
2639 }
2640
2641 ret = LTTCOMM_OK;
2642
2643 error:
2644 return ret;
2645 }
2646
2647 /*
2648 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2649 */
2650 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2651 char *channel_name, int event_type)
2652 {
2653 int ret;
2654 struct ltt_kernel_channel *kchan;
2655
2656 switch (domain) {
2657 case LTTNG_DOMAIN_KERNEL:
2658 kchan = trace_kernel_get_channel_by_name(channel_name,
2659 session->kernel_session);
2660 if (kchan == NULL) {
2661 /* This call will notify the kernel thread */
2662 ret = channel_kernel_create(session->kernel_session, NULL,
2663 kernel_poll_pipe[1]);
2664 if (ret != LTTCOMM_OK) {
2665 goto error;
2666 }
2667
2668 /* Get the newly created kernel channel pointer */
2669 kchan = trace_kernel_get_channel_by_name(channel_name,
2670 session->kernel_session);
2671 if (kchan == NULL) {
2672 /* This sould not happen... */
2673 ret = LTTCOMM_FATAL;
2674 goto error;
2675 }
2676
2677 }
2678
2679 switch (event_type) {
2680 case LTTNG_EVENT_SYSCALL:
2681 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2682 kchan, kernel_tracer_fd);
2683 break;
2684 case LTTNG_EVENT_TRACEPOINT:
2685 /*
2686 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2687 * events already registered to the channel.
2688 */
2689 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2690 kchan, kernel_tracer_fd);
2691 break;
2692 case LTTNG_EVENT_ALL:
2693 /* Enable syscalls and tracepoints */
2694 ret = event_kernel_enable_all(session->kernel_session,
2695 kchan, kernel_tracer_fd);
2696 break;
2697 default:
2698 ret = LTTCOMM_KERN_ENABLE_FAIL;
2699 goto error;
2700 }
2701
2702 /* Manage return value */
2703 if (ret != LTTCOMM_OK) {
2704 goto error;
2705 }
2706
2707 kernel_wait_quiescent(kernel_tracer_fd);
2708 break;
2709 case LTTNG_DOMAIN_UST:
2710 {
2711 struct lttng_channel *attr;
2712 struct ltt_ust_channel *uchan;
2713 struct ltt_ust_session *usess = session->ust_session;
2714
2715 /* Get channel from global UST domain */
2716 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2717 channel_name);
2718 if (uchan == NULL) {
2719 /* Create default channel */
2720 attr = channel_new_default_attr(domain);
2721 if (attr == NULL) {
2722 ret = LTTCOMM_FATAL;
2723 goto error;
2724 }
2725 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2726 attr->name[NAME_MAX - 1] = '\0';
2727
2728 /* Use the internal command enable channel */
2729 ret = channel_ust_create(usess, domain, attr);
2730 if (ret != LTTCOMM_OK) {
2731 free(attr);
2732 goto error;
2733 }
2734 free(attr);
2735
2736 /* Get the newly created channel reference back */
2737 uchan = trace_ust_find_channel_by_name(
2738 usess->domain_global.channels, channel_name);
2739 if (uchan == NULL) {
2740 /* Something is really wrong */
2741 ret = LTTCOMM_FATAL;
2742 goto error;
2743 }
2744 }
2745
2746 /* At this point, the session and channel exist on the tracer */
2747
2748 switch (event_type) {
2749 case LTTNG_EVENT_ALL:
2750 case LTTNG_EVENT_TRACEPOINT:
2751 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
2752 if (ret != LTTCOMM_OK) {
2753 goto error;
2754 }
2755 break;
2756 default:
2757 ret = LTTCOMM_UST_ENABLE_FAIL;
2758 goto error;
2759 }
2760
2761 /* Manage return value */
2762 if (ret != LTTCOMM_OK) {
2763 goto error;
2764 }
2765
2766 break;
2767 }
2768 #if 0
2769 case LTTNG_DOMAIN_UST_EXEC_NAME:
2770 case LTTNG_DOMAIN_UST_PID:
2771 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2772 #endif
2773 default:
2774 ret = LTTCOMM_UND;
2775 goto error;
2776 }
2777
2778 ret = LTTCOMM_OK;
2779
2780 error:
2781 return ret;
2782 }
2783
2784 /*
2785 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2786 */
2787 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2788 {
2789 int ret;
2790 ssize_t nb_events = 0;
2791
2792 switch (domain) {
2793 case LTTNG_DOMAIN_KERNEL:
2794 nb_events = kernel_list_events(kernel_tracer_fd, events);
2795 if (nb_events < 0) {
2796 ret = LTTCOMM_KERN_LIST_FAIL;
2797 goto error;
2798 }
2799 break;
2800 case LTTNG_DOMAIN_UST:
2801 nb_events = ust_app_list_events(events);
2802 if (nb_events < 0) {
2803 ret = LTTCOMM_UST_LIST_FAIL;
2804 goto error;
2805 }
2806 break;
2807 default:
2808 ret = LTTCOMM_UND;
2809 goto error;
2810 }
2811
2812 return nb_events;
2813
2814 error:
2815 /* Return negative value to differentiate return code */
2816 return -ret;
2817 }
2818
2819 /*
2820 * Command LTTNG_START_TRACE processed by the client thread.
2821 */
2822 static int cmd_start_trace(struct ltt_session *session)
2823 {
2824 int ret;
2825 struct ltt_kernel_session *ksession;
2826 struct ltt_ust_session *usess;
2827
2828 /* Short cut */
2829 ksession = session->kernel_session;
2830 usess = session->ust_session;
2831
2832 if (session->enabled) {
2833 ret = LTTCOMM_UST_START_FAIL;
2834 goto error;
2835 }
2836
2837 session->enabled = 1;
2838
2839 /* Kernel tracing */
2840 if (ksession != NULL) {
2841 struct ltt_kernel_channel *kchan;
2842
2843 /* Open kernel metadata */
2844 if (ksession->metadata == NULL) {
2845 ret = kernel_open_metadata(ksession, ksession->trace_path);
2846 if (ret < 0) {
2847 ret = LTTCOMM_KERN_META_FAIL;
2848 goto error;
2849 }
2850 }
2851
2852 /* Open kernel metadata stream */
2853 if (ksession->metadata_stream_fd == 0) {
2854 ret = kernel_open_metadata_stream(ksession);
2855 if (ret < 0) {
2856 ERR("Kernel create metadata stream failed");
2857 ret = LTTCOMM_KERN_STREAM_FAIL;
2858 goto error;
2859 }
2860 }
2861
2862 /* For each channel */
2863 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2864 if (kchan->stream_count == 0) {
2865 ret = kernel_open_channel_stream(kchan);
2866 if (ret < 0) {
2867 ret = LTTCOMM_KERN_STREAM_FAIL;
2868 goto error;
2869 }
2870 /* Update the stream global counter */
2871 ksession->stream_count_global += ret;
2872 }
2873 }
2874
2875 /* Setup kernel consumer socket and send fds to it */
2876 ret = init_kernel_tracing(ksession);
2877 if (ret < 0) {
2878 ret = LTTCOMM_KERN_START_FAIL;
2879 goto error;
2880 }
2881
2882 /* This start the kernel tracing */
2883 ret = kernel_start_session(ksession);
2884 if (ret < 0) {
2885 ret = LTTCOMM_KERN_START_FAIL;
2886 goto error;
2887 }
2888
2889 /* Quiescent wait after starting trace */
2890 kernel_wait_quiescent(kernel_tracer_fd);
2891 }
2892
2893 /* Flag session that trace should start automatically */
2894 if (usess) {
2895 usess->start_trace = 1;
2896
2897 ret = ust_app_start_trace_all(usess);
2898 if (ret < 0) {
2899 ret = LTTCOMM_UST_START_FAIL;
2900 goto error;
2901 }
2902 }
2903
2904 ret = LTTCOMM_OK;
2905
2906 error:
2907 return ret;
2908 }
2909
2910 /*
2911 * Command LTTNG_STOP_TRACE processed by the client thread.
2912 */
2913 static int cmd_stop_trace(struct ltt_session *session)
2914 {
2915 int ret;
2916 struct ltt_kernel_channel *kchan;
2917 struct ltt_kernel_session *ksession;
2918 struct ltt_ust_session *usess;
2919
2920 /* Short cut */
2921 ksession = session->kernel_session;
2922 usess = session->ust_session;
2923
2924 if (!session->enabled) {
2925 ret = LTTCOMM_UST_STOP_FAIL;
2926 goto error;
2927 }
2928
2929 session->enabled = 0;
2930
2931 /* Kernel tracer */
2932 if (ksession != NULL) {
2933 DBG("Stop kernel tracing");
2934
2935 /* Flush all buffers before stopping */
2936 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2937 if (ret < 0) {
2938 ERR("Kernel metadata flush failed");
2939 }
2940
2941 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2942 ret = kernel_flush_buffer(kchan);
2943 if (ret < 0) {
2944 ERR("Kernel flush buffer error");
2945 }
2946 }
2947
2948 ret = kernel_stop_session(ksession);
2949 if (ret < 0) {
2950 ret = LTTCOMM_KERN_STOP_FAIL;
2951 goto error;
2952 }
2953
2954 kernel_wait_quiescent(kernel_tracer_fd);
2955 }
2956
2957 if (usess) {
2958 usess->start_trace = 0;
2959
2960 ret = ust_app_stop_trace_all(usess);
2961 if (ret < 0) {
2962 ret = LTTCOMM_UST_STOP_FAIL;
2963 goto error;
2964 }
2965 }
2966
2967 ret = LTTCOMM_OK;
2968
2969 error:
2970 return ret;
2971 }
2972
2973 /*
2974 * Command LTTNG_CREATE_SESSION processed by the client thread.
2975 */
2976 static int cmd_create_session(char *name, char *path, struct ucred *creds)
2977 {
2978 int ret;
2979
2980 ret = session_create(name, path, creds->uid, creds->gid);
2981 if (ret != LTTCOMM_OK) {
2982 goto error;
2983 }
2984
2985 ret = LTTCOMM_OK;
2986
2987 error:
2988 return ret;
2989 }
2990
2991 /*
2992 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2993 */
2994 static int cmd_destroy_session(struct ltt_session *session, char *name)
2995 {
2996 int ret;
2997
2998 /* Clean kernel session teardown */
2999 teardown_kernel_session(session);
3000 /* UST session teardown */
3001 teardown_ust_session(session);
3002
3003 /*
3004 * Must notify the kernel thread here to update it's poll setin order
3005 * to remove the channel(s)' fd just destroyed.
3006 */
3007 ret = notify_thread_pipe(kernel_poll_pipe[1]);
3008 if (ret < 0) {
3009 PERROR("write kernel poll pipe");
3010 }
3011
3012 ret = session_destroy(session);
3013
3014 return ret;
3015 }
3016
3017 /*
3018 * Command LTTNG_CALIBRATE processed by the client thread.
3019 */
3020 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
3021 {
3022 int ret;
3023
3024 switch (domain) {
3025 case LTTNG_DOMAIN_KERNEL:
3026 {
3027 struct lttng_kernel_calibrate kcalibrate;
3028
3029 kcalibrate.type = calibrate->type;
3030 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
3031 if (ret < 0) {
3032 ret = LTTCOMM_KERN_ENABLE_FAIL;
3033 goto error;
3034 }
3035 break;
3036 }
3037 case LTTNG_DOMAIN_UST:
3038 {
3039 struct lttng_ust_calibrate ucalibrate;
3040
3041 ucalibrate.type = calibrate->type;
3042 ret = ust_app_calibrate_glb(&ucalibrate);
3043 if (ret < 0) {
3044 ret = LTTCOMM_UST_CALIBRATE_FAIL;
3045 goto error;
3046 }
3047 break;
3048 }
3049 default:
3050 ret = LTTCOMM_UND;
3051 goto error;
3052 }
3053
3054 ret = LTTCOMM_OK;
3055
3056 error:
3057 return ret;
3058 }
3059
3060 /*
3061 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3062 */
3063 static int cmd_register_consumer(struct ltt_session *session, int domain,
3064 char *sock_path)
3065 {
3066 int ret, sock;
3067
3068 switch (domain) {
3069 case LTTNG_DOMAIN_KERNEL:
3070 /* Can't register a consumer if there is already one */
3071 if (session->kernel_session->consumer_fds_sent != 0) {
3072 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3073 goto error;
3074 }
3075
3076 sock = lttcomm_connect_unix_sock(sock_path);
3077 if (sock < 0) {
3078 ret = LTTCOMM_CONNECT_FAIL;
3079 goto error;
3080 }
3081
3082 session->kernel_session->consumer_fd = sock;
3083 break;
3084 default:
3085 /* TODO: Userspace tracing */
3086 ret = LTTCOMM_UND;
3087 goto error;
3088 }
3089
3090 ret = LTTCOMM_OK;
3091
3092 error:
3093 return ret;
3094 }
3095
3096 /*
3097 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3098 */
3099 static ssize_t cmd_list_domains(struct ltt_session *session,
3100 struct lttng_domain **domains)
3101 {
3102 int ret, index = 0;
3103 ssize_t nb_dom = 0;
3104
3105 if (session->kernel_session != NULL) {
3106 DBG3("Listing domains found kernel domain");
3107 nb_dom++;
3108 }
3109
3110 if (session->ust_session != NULL) {
3111 DBG3("Listing domains found UST global domain");
3112 nb_dom++;
3113 }
3114
3115 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3116 if (*domains == NULL) {
3117 ret = -LTTCOMM_FATAL;
3118 goto error;
3119 }
3120
3121 if (session->kernel_session != NULL) {
3122 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3123 index++;
3124 }
3125
3126 if (session->ust_session != NULL) {
3127 (*domains)[index].type = LTTNG_DOMAIN_UST;
3128 index++;
3129 }
3130
3131 return nb_dom;
3132
3133 error:
3134 return ret;
3135 }
3136
3137 /*
3138 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3139 */
3140 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
3141 struct lttng_channel **channels)
3142 {
3143 int ret;
3144 ssize_t nb_chan = 0;
3145
3146 switch (domain) {
3147 case LTTNG_DOMAIN_KERNEL:
3148 if (session->kernel_session != NULL) {
3149 nb_chan = session->kernel_session->channel_count;
3150 }
3151 DBG3("Number of kernel channels %zd", nb_chan);
3152 break;
3153 case LTTNG_DOMAIN_UST:
3154 if (session->ust_session != NULL) {
3155 nb_chan = lttng_ht_get_count(
3156 session->ust_session->domain_global.channels);
3157 }
3158 DBG3("Number of UST global channels %zd", nb_chan);
3159 break;
3160 default:
3161 *channels = NULL;
3162 ret = -LTTCOMM_UND;
3163 goto error;
3164 }
3165
3166 if (nb_chan > 0) {
3167 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
3168 if (*channels == NULL) {
3169 ret = -LTTCOMM_FATAL;
3170 goto error;
3171 }
3172
3173 list_lttng_channels(domain, session, *channels);
3174 } else {
3175 *channels = NULL;
3176 }
3177
3178 return nb_chan;
3179
3180 error:
3181 return ret;
3182 }
3183
3184 /*
3185 * Command LTTNG_LIST_EVENTS processed by the client thread.
3186 */
3187 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
3188 char *channel_name, struct lttng_event **events)
3189 {
3190 int ret = 0;
3191 ssize_t nb_event = 0;
3192
3193 switch (domain) {
3194 case LTTNG_DOMAIN_KERNEL:
3195 if (session->kernel_session != NULL) {
3196 nb_event = list_lttng_kernel_events(channel_name,
3197 session->kernel_session, events);
3198 }
3199 break;
3200 case LTTNG_DOMAIN_UST:
3201 {
3202 if (session->ust_session != NULL) {
3203 nb_event = list_lttng_ust_global_events(channel_name,
3204 &session->ust_session->domain_global, events);
3205 }
3206 break;
3207 }
3208 default:
3209 ret = -LTTCOMM_UND;
3210 goto error;
3211 }
3212
3213 ret = nb_event;
3214
3215 error:
3216 return ret;
3217 }
3218
3219 /*
3220 * Process the command requested by the lttng client within the command
3221 * context structure. This function make sure that the return structure (llm)
3222 * is set and ready for transmission before returning.
3223 *
3224 * Return any error encountered or 0 for success.
3225 */
3226 static int process_client_msg(struct command_ctx *cmd_ctx)
3227 {
3228 int ret = LTTCOMM_OK;
3229 int need_tracing_session = 1;
3230 int need_domain;
3231
3232 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
3233
3234 switch (cmd_ctx->lsm->cmd_type) {
3235 case LTTNG_CREATE_SESSION:
3236 case LTTNG_DESTROY_SESSION:
3237 case LTTNG_LIST_SESSIONS:
3238 case LTTNG_LIST_DOMAINS:
3239 case LTTNG_START_TRACE:
3240 case LTTNG_STOP_TRACE:
3241 need_domain = 0;
3242 break;
3243 default:
3244 need_domain = 1;
3245 }
3246
3247 if (opt_no_kernel && need_domain
3248 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
3249 ret = LTTCOMM_KERN_NA;
3250 goto error;
3251 }
3252
3253 /*
3254 * Check for command that don't needs to allocate a returned payload. We do
3255 * this here so we don't have to make the call for no payload at each
3256 * command.
3257 */
3258 switch(cmd_ctx->lsm->cmd_type) {
3259 case LTTNG_LIST_SESSIONS:
3260 case LTTNG_LIST_TRACEPOINTS:
3261 case LTTNG_LIST_DOMAINS:
3262 case LTTNG_LIST_CHANNELS:
3263 case LTTNG_LIST_EVENTS:
3264 break;
3265 default:
3266 /* Setup lttng message with no payload */
3267 ret = setup_lttng_msg(cmd_ctx, 0);
3268 if (ret < 0) {
3269 /* This label does not try to unlock the session */
3270 goto init_setup_error;
3271 }
3272 }
3273
3274 /* Commands that DO NOT need a session. */
3275 switch (cmd_ctx->lsm->cmd_type) {
3276 case LTTNG_CREATE_SESSION:
3277 case LTTNG_CALIBRATE:
3278 case LTTNG_LIST_SESSIONS:
3279 case LTTNG_LIST_TRACEPOINTS:
3280 need_tracing_session = 0;
3281 break;
3282 default:
3283 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
3284 session_lock_list();
3285 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
3286 session_unlock_list();
3287 if (cmd_ctx->session == NULL) {
3288 if (cmd_ctx->lsm->session.name != NULL) {
3289 ret = LTTCOMM_SESS_NOT_FOUND;
3290 } else {
3291 /* If no session name specified */
3292 ret = LTTCOMM_SELECT_SESS;
3293 }
3294 goto error;
3295 } else {
3296 /* Acquire lock for the session */
3297 session_lock(cmd_ctx->session);
3298 }
3299 break;
3300 }
3301
3302 if (!need_domain) {
3303 goto skip_domain;
3304 }
3305 /*
3306 * Check domain type for specific "pre-action".
3307 */
3308 switch (cmd_ctx->lsm->domain.type) {
3309 case LTTNG_DOMAIN_KERNEL:
3310 if (!is_root) {
3311 ret = LTTCOMM_KERN_NA;
3312 goto error;
3313 }
3314
3315 /* Kernel tracer check */
3316 if (kernel_tracer_fd == -1) {
3317 /* Basically, load kernel tracer modules */
3318 ret = init_kernel_tracer();
3319 if (ret != 0) {
3320 goto error;
3321 }
3322 }
3323
3324 /* Need a session for kernel command */
3325 if (need_tracing_session) {
3326 if (cmd_ctx->session->kernel_session == NULL) {
3327 ret = create_kernel_session(cmd_ctx->session);
3328 if (ret < 0) {
3329 ret = LTTCOMM_KERN_SESS_FAIL;
3330 goto error;
3331 }
3332 }
3333
3334 /* Start the kernel consumer daemon */
3335 pthread_mutex_lock(&kconsumer_data.pid_mutex);
3336 if (kconsumer_data.pid == 0 &&
3337 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3338 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3339 ret = start_consumerd(&kconsumer_data);
3340 if (ret < 0) {
3341 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3342 goto error;
3343 }
3344 } else {
3345 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
3346 }
3347 }
3348 break;
3349 case LTTNG_DOMAIN_UST:
3350 {
3351 if (need_tracing_session) {
3352 if (cmd_ctx->session->ust_session == NULL) {
3353 ret = create_ust_session(cmd_ctx->session,
3354 &cmd_ctx->lsm->domain);
3355 if (ret != LTTCOMM_OK) {
3356 goto error;
3357 }
3358 }
3359 /* Start the UST consumer daemons */
3360 /* 64-bit */
3361 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
3362 if (consumerd64_bin[0] != '\0' &&
3363 ustconsumer64_data.pid == 0 &&
3364 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3365 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
3366 ret = start_consumerd(&ustconsumer64_data);
3367 if (ret < 0) {
3368 ret = LTTCOMM_UST_CONSUMER64_FAIL;
3369 ust_consumerd64_fd = -EINVAL;
3370 goto error;
3371 }
3372
3373 ust_consumerd64_fd = ustconsumer64_data.cmd_sock;
3374 } else {
3375 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
3376 }
3377 /* 32-bit */
3378 if (consumerd32_bin[0] != '\0' &&
3379 ustconsumer32_data.pid == 0 &&
3380 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
3381 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
3382 ret = start_consumerd(&ustconsumer32_data);
3383 if (ret < 0) {
3384 ret = LTTCOMM_UST_CONSUMER32_FAIL;
3385 ust_consumerd32_fd = -EINVAL;
3386 goto error;
3387 }
3388 ust_consumerd32_fd = ustconsumer32_data.cmd_sock;
3389 } else {
3390 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
3391 }
3392 }
3393 break;
3394 }
3395 default:
3396 break;
3397 }
3398 skip_domain:
3399
3400 /*
3401 * Check that the UID or GID match that of the tracing session.
3402 * The root user can interact with all sessions.
3403 */
3404 if (need_tracing_session) {
3405 if (!session_access_ok(cmd_ctx->session,
3406 cmd_ctx->creds.uid, cmd_ctx->creds.gid)) {
3407 ret = LTTCOMM_EPERM;
3408 goto error;
3409 }
3410 }
3411
3412 /* Process by command type */
3413 switch (cmd_ctx->lsm->cmd_type) {
3414 case LTTNG_ADD_CONTEXT:
3415 {
3416 ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3417 cmd_ctx->lsm->u.context.channel_name,
3418 cmd_ctx->lsm->u.context.event_name,
3419 &cmd_ctx->lsm->u.context.ctx);
3420 break;
3421 }
3422 case LTTNG_DISABLE_CHANNEL:
3423 {
3424 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3425 cmd_ctx->lsm->u.disable.channel_name);
3426 break;
3427 }
3428 case LTTNG_DISABLE_EVENT:
3429 {
3430 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3431 cmd_ctx->lsm->u.disable.channel_name,
3432 cmd_ctx->lsm->u.disable.name);
3433 break;
3434 }
3435 case LTTNG_DISABLE_ALL_EVENT:
3436 {
3437 DBG("Disabling all events");
3438
3439 ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3440 cmd_ctx->lsm->u.disable.channel_name);
3441 break;
3442 }
3443 case LTTNG_ENABLE_CHANNEL:
3444 {
3445 ret = cmd_enable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3446 &cmd_ctx->lsm->u.channel.chan);
3447 break;
3448 }
3449 case LTTNG_ENABLE_EVENT:
3450 {
3451 ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3452 cmd_ctx->lsm->u.enable.channel_name,
3453 &cmd_ctx->lsm->u.enable.event);
3454 break;
3455 }
3456 case LTTNG_ENABLE_ALL_EVENT:
3457 {
3458 DBG("Enabling all events");
3459
3460 ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3461 cmd_ctx->lsm->u.enable.channel_name,
3462 cmd_ctx->lsm->u.enable.event.type);
3463 break;
3464 }
3465 case LTTNG_LIST_TRACEPOINTS:
3466 {
3467 struct lttng_event *events;
3468 ssize_t nb_events;
3469
3470 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
3471 if (nb_events < 0) {
3472 ret = -nb_events;
3473 goto error;
3474 }
3475
3476 /*
3477 * Setup lttng message with payload size set to the event list size in
3478 * bytes and then copy list into the llm payload.
3479 */
3480 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
3481 if (ret < 0) {
3482 free(events);
3483 goto setup_error;
3484 }
3485
3486 /* Copy event list into message payload */
3487 memcpy(cmd_ctx->llm->payload, events,
3488 sizeof(struct lttng_event) * nb_events);
3489
3490 free(events);
3491
3492 ret = LTTCOMM_OK;
3493 break;
3494 }
3495 case LTTNG_START_TRACE:
3496 {
3497 ret = cmd_start_trace(cmd_ctx->session);
3498 break;
3499 }
3500 case LTTNG_STOP_TRACE:
3501 {
3502 ret = cmd_stop_trace(cmd_ctx->session);
3503 break;
3504 }
3505 case LTTNG_CREATE_SESSION:
3506 {
3507 ret = cmd_create_session(cmd_ctx->lsm->session.name,
3508 cmd_ctx->lsm->session.path, &cmd_ctx->creds);
3509 break;
3510 }
3511 case LTTNG_DESTROY_SESSION:
3512 {
3513 ret = cmd_destroy_session(cmd_ctx->session,
3514 cmd_ctx->lsm->session.name);
3515 break;
3516 }
3517 case LTTNG_LIST_DOMAINS:
3518 {
3519 ssize_t nb_dom;
3520 struct lttng_domain *domains;
3521
3522 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
3523 if (nb_dom < 0) {
3524 ret = -nb_dom;
3525 goto error;
3526 }
3527
3528 ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
3529 if (ret < 0) {
3530 goto setup_error;
3531 }
3532
3533 /* Copy event list into message payload */
3534 memcpy(cmd_ctx->llm->payload, domains,
3535 nb_dom * sizeof(struct lttng_domain));
3536
3537 free(domains);
3538
3539 ret = LTTCOMM_OK;
3540 break;
3541 }
3542 case LTTNG_LIST_CHANNELS:
3543 {
3544 size_t nb_chan;
3545 struct lttng_channel *channels;
3546
3547 nb_chan = cmd_list_channels(cmd_ctx->lsm->domain.type,
3548 cmd_ctx->session, &channels);
3549 if (nb_chan < 0) {
3550 ret = -nb_chan;
3551 goto error;
3552 }
3553
3554 ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
3555 if (ret < 0) {
3556 goto setup_error;
3557 }
3558
3559 /* Copy event list into message payload */
3560 memcpy(cmd_ctx->llm->payload, channels,
3561 nb_chan * sizeof(struct lttng_channel));
3562
3563 free(channels);
3564
3565 ret = LTTCOMM_OK;
3566 break;
3567 }
3568 case LTTNG_LIST_EVENTS:
3569 {
3570 ssize_t nb_event;
3571 struct lttng_event *events = NULL;
3572
3573 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type, cmd_ctx->session,
3574 cmd_ctx->lsm->u.list.channel_name, &events);
3575 if (nb_event < 0) {
3576 ret = -nb_event;
3577 goto error;
3578 }
3579
3580 ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
3581 if (ret < 0) {
3582 goto setup_error;
3583 }
3584
3585 /* Copy event list into message payload */
3586 memcpy(cmd_ctx->llm->payload, events,
3587 nb_event * sizeof(struct lttng_event));
3588
3589 free(events);
3590
3591 ret = LTTCOMM_OK;
3592 break;
3593 }
3594 case LTTNG_LIST_SESSIONS:
3595 {
3596 unsigned int nr_sessions;
3597
3598 session_lock_list();
3599 nr_sessions = lttng_sessions_count(cmd_ctx->creds.uid, cmd_ctx->creds.gid);
3600
3601 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * nr_sessions);
3602 if (ret < 0) {
3603 session_unlock_list();
3604 goto setup_error;
3605 }
3606
3607 /* Filled the session array */
3608 list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload),
3609 cmd_ctx->creds.uid, cmd_ctx->creds.gid);
3610
3611 session_unlock_list();
3612
3613 ret = LTTCOMM_OK;
3614 break;
3615 }
3616 case LTTNG_CALIBRATE:
3617 {
3618 ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
3619 &cmd_ctx->lsm->u.calibrate);
3620 break;
3621 }
3622 case LTTNG_REGISTER_CONSUMER:
3623 {
3624 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
3625 cmd_ctx->lsm->u.reg.path);
3626 break;
3627 }
3628 default:
3629 ret = LTTCOMM_UND;
3630 break;
3631 }
3632
3633 error:
3634 if (cmd_ctx->llm == NULL) {
3635 DBG("Missing llm structure. Allocating one.");
3636 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
3637 goto setup_error;
3638 }
3639 }
3640 /* Set return code */
3641 cmd_ctx->llm->ret_code = ret;
3642 setup_error:
3643 if (cmd_ctx->session) {
3644 session_unlock(cmd_ctx->session);
3645 }
3646 init_setup_error:
3647 return ret;
3648 }
3649
3650 /*
3651 * This thread manage all clients request using the unix client socket for
3652 * communication.
3653 */
3654 static void *thread_manage_clients(void *data)
3655 {
3656 int sock = -1, ret, i, pollfd;
3657 uint32_t revents, nb_fd;
3658 struct command_ctx *cmd_ctx = NULL;
3659 struct lttng_poll_event events;
3660
3661 DBG("[thread] Manage client started");
3662
3663 rcu_register_thread();
3664
3665 ret = lttcomm_listen_unix_sock(client_sock);
3666 if (ret < 0) {
3667 goto error;
3668 }
3669
3670 /*
3671 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
3672 * more will be added to this poll set.
3673 */
3674 ret = create_thread_poll_set(&events, 2);
3675 if (ret < 0) {
3676 goto error;
3677 }
3678
3679 /* Add the application registration socket */
3680 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
3681 if (ret < 0) {
3682 goto error;
3683 }
3684
3685 /*
3686 * Notify parent pid that we are ready to accept command for client side.
3687 */
3688 if (opt_sig_parent) {
3689 kill(ppid, SIGUSR1);
3690 }
3691
3692 while (1) {
3693 DBG("Accepting client command ...");
3694
3695 nb_fd = LTTNG_POLL_GETNB(&events);
3696
3697 /* Inifinite blocking call, waiting for transmission */
3698 restart:
3699 ret = lttng_poll_wait(&events, -1);
3700 if (ret < 0) {
3701 /*
3702 * Restart interrupted system call.
3703 */
3704 if (errno == EINTR) {
3705 goto restart;
3706 }
3707 goto error;
3708 }
3709
3710 for (i = 0; i < nb_fd; i++) {
3711 /* Fetch once the poll data */
3712 revents = LTTNG_POLL_GETEV(&events, i);
3713 pollfd = LTTNG_POLL_GETFD(&events, i);
3714
3715 /* Thread quit pipe has been closed. Killing thread. */
3716 ret = check_thread_quit_pipe(pollfd, revents);
3717 if (ret) {
3718 goto error;
3719 }
3720
3721 /* Event on the registration socket */
3722 if (pollfd == client_sock) {
3723 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
3724 ERR("Client socket poll error");
3725 goto error;
3726 }
3727 }
3728 }
3729
3730 DBG("Wait for client response");
3731
3732 sock = lttcomm_accept_unix_sock(client_sock);
3733 if (sock < 0) {
3734 goto error;
3735 }
3736
3737 /* Set socket option for credentials retrieval */
3738 ret = lttcomm_setsockopt_creds_unix_sock(sock);
3739 if (ret < 0) {
3740 goto error;
3741 }
3742
3743 /* Allocate context command to process the client request */
3744 cmd_ctx = zmalloc(sizeof(struct command_ctx));
3745 if (cmd_ctx == NULL) {
3746 PERROR("zmalloc cmd_ctx");
3747 goto error;
3748 }
3749
3750 /* Allocate data buffer for reception */
3751 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
3752 if (cmd_ctx->lsm == NULL) {
3753 PERROR("zmalloc cmd_ctx->lsm");
3754 goto error;
3755 }
3756
3757 cmd_ctx->llm = NULL;
3758 cmd_ctx->session = NULL;
3759
3760 /*
3761 * Data is received from the lttng client. The struct
3762 * lttcomm_session_msg (lsm) contains the command and data request of
3763 * the client.
3764 */
3765 DBG("Receiving data from client ...");
3766 ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
3767 sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
3768 if (ret <= 0) {
3769 DBG("Nothing recv() from client... continuing");
3770 ret = close(sock);
3771 if (ret) {
3772 PERROR("close");