Fix: sessiond app listening: use posix-compliant poll flags
[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;
126 static int apps_sock;
127 static int kernel_tracer_fd;
128 static int kernel_poll_pipe[2];
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];
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];
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;
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 close(kernel_tracer_fd);
423 DBG("Unloading kernel modules");
424 modprobe_remove_lttng_all();
425 }
426
427 close(thread_quit_pipe[0]);
428 close(thread_quit_pipe[1]);
429
430 /* <fun> */
431 DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
432 "Matthew, BEET driven development works!%c[%dm",
433 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
434 /* </fun> */
435 }
436
437 /*
438 * Send data on a unix socket using the liblttsessiondcomm API.
439 *
440 * Return lttcomm error code.
441 */
442 static int send_unix_sock(int sock, void *buf, size_t len)
443 {
444 /* Check valid length */
445 if (len <= 0) {
446 return -1;
447 }
448
449 return lttcomm_send_unix_sock(sock, buf, len);
450 }
451
452 /*
453 * Free memory of a command context structure.
454 */
455 static void clean_command_ctx(struct command_ctx **cmd_ctx)
456 {
457 DBG("Clean command context structure");
458 if (*cmd_ctx) {
459 if ((*cmd_ctx)->llm) {
460 free((*cmd_ctx)->llm);
461 }
462 if ((*cmd_ctx)->lsm) {
463 free((*cmd_ctx)->lsm);
464 }
465 free(*cmd_ctx);
466 *cmd_ctx = NULL;
467 }
468 }
469
470 /*
471 * Send all stream fds of kernel channel to the consumer.
472 */
473 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
474 int sock, struct ltt_kernel_channel *channel,
475 uid_t uid, gid_t gid)
476 {
477 int ret;
478 struct ltt_kernel_stream *stream;
479 struct lttcomm_consumer_msg lkm;
480
481 DBG("Sending streams of channel %s to kernel consumer",
482 channel->channel->name);
483
484 /* Send channel */
485 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
486 lkm.u.channel.channel_key = channel->fd;
487 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
488 lkm.u.channel.mmap_len = 0; /* for kernel */
489 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
490 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
491 if (ret < 0) {
492 perror("send consumer channel");
493 goto error;
494 }
495
496 /* Send streams */
497 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
498 if (!stream->fd) {
499 continue;
500 }
501 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
502 lkm.u.stream.channel_key = channel->fd;
503 lkm.u.stream.stream_key = stream->fd;
504 lkm.u.stream.state = stream->state;
505 lkm.u.stream.output = channel->channel->attr.output;
506 lkm.u.stream.mmap_len = 0; /* for kernel */
507 lkm.u.stream.uid = uid;
508 lkm.u.stream.gid = gid;
509 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
510 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
511 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
512 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
513 if (ret < 0) {
514 perror("send consumer stream");
515 goto error;
516 }
517 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
518 if (ret < 0) {
519 perror("send consumer stream ancillary data");
520 goto error;
521 }
522 }
523
524 DBG("consumer channel streams sent");
525
526 return 0;
527
528 error:
529 return ret;
530 }
531
532 /*
533 * Send all stream fds of the kernel session to the consumer.
534 */
535 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
536 struct ltt_kernel_session *session)
537 {
538 int ret;
539 struct ltt_kernel_channel *chan;
540 struct lttcomm_consumer_msg lkm;
541 int sock = session->consumer_fd;
542
543 DBG("Sending metadata stream fd");
544
545 /* Extra protection. It's NOT supposed to be set to 0 at this point */
546 if (session->consumer_fd == 0) {
547 session->consumer_fd = consumer_data->cmd_sock;
548 }
549
550 if (session->metadata_stream_fd != 0) {
551 /* Send metadata channel fd */
552 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
553 lkm.u.channel.channel_key = session->metadata->fd;
554 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
555 lkm.u.channel.mmap_len = 0; /* for kernel */
556 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
557 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
558 if (ret < 0) {
559 perror("send consumer channel");
560 goto error;
561 }
562
563 /* Send metadata stream fd */
564 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
565 lkm.u.stream.channel_key = session->metadata->fd;
566 lkm.u.stream.stream_key = session->metadata_stream_fd;
567 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
568 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
569 lkm.u.stream.mmap_len = 0; /* for kernel */
570 lkm.u.stream.uid = session->uid;
571 lkm.u.stream.gid = session->gid;
572 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
573 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
574 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
575 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
576 if (ret < 0) {
577 perror("send consumer stream");
578 goto error;
579 }
580 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
581 if (ret < 0) {
582 perror("send consumer stream");
583 goto error;
584 }
585 }
586
587 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
588 ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
589 session->uid, session->gid);
590 if (ret < 0) {
591 goto error;
592 }
593 }
594
595 DBG("consumer fds (metadata and channel streams) sent");
596
597 return 0;
598
599 error:
600 return ret;
601 }
602
603 /*
604 * Notify UST applications using the shm mmap futex.
605 */
606 static int notify_ust_apps(int active)
607 {
608 char *wait_shm_mmap;
609
610 DBG("Notifying applications of session daemon state: %d", active);
611
612 /* See shm.c for this call implying mmap, shm and futex calls */
613 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
614 if (wait_shm_mmap == NULL) {
615 goto error;
616 }
617
618 /* Wake waiting process */
619 futex_wait_update((int32_t *) wait_shm_mmap, active);
620
621 /* Apps notified successfully */
622 return 0;
623
624 error:
625 return -1;
626 }
627
628 /*
629 * Setup the outgoing data buffer for the response (llm) by allocating the
630 * right amount of memory and copying the original information from the lsm
631 * structure.
632 *
633 * Return total size of the buffer pointed by buf.
634 */
635 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
636 {
637 int ret, buf_size;
638
639 buf_size = size;
640
641 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
642 if (cmd_ctx->llm == NULL) {
643 perror("zmalloc");
644 ret = -ENOMEM;
645 goto error;
646 }
647
648 /* Copy common data */
649 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
650 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
651
652 cmd_ctx->llm->data_size = size;
653 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
654
655 return buf_size;
656
657 error:
658 return ret;
659 }
660
661 /*
662 * Update the kernel poll set of all channel fd available over all tracing
663 * session. Add the wakeup pipe at the end of the set.
664 */
665 static int update_kernel_poll(struct lttng_poll_event *events)
666 {
667 int ret;
668 struct ltt_session *session;
669 struct ltt_kernel_channel *channel;
670
671 DBG("Updating kernel poll set");
672
673 session_lock_list();
674 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
675 session_lock(session);
676 if (session->kernel_session == NULL) {
677 session_unlock(session);
678 continue;
679 }
680
681 cds_list_for_each_entry(channel,
682 &session->kernel_session->channel_list.head, list) {
683 /* Add channel fd to the kernel poll set */
684 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
685 if (ret < 0) {
686 session_unlock(session);
687 goto error;
688 }
689 DBG("Channel fd %d added to kernel set", channel->fd);
690 }
691 session_unlock(session);
692 }
693 session_unlock_list();
694
695 return 0;
696
697 error:
698 session_unlock_list();
699 return -1;
700 }
701
702 /*
703 * Find the channel fd from 'fd' over all tracing session. When found, check
704 * for new channel stream and send those stream fds to the kernel consumer.
705 *
706 * Useful for CPU hotplug feature.
707 */
708 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
709 {
710 int ret = 0;
711 struct ltt_session *session;
712 struct ltt_kernel_channel *channel;
713
714 DBG("Updating kernel streams for channel fd %d", fd);
715
716 session_lock_list();
717 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
718 session_lock(session);
719 if (session->kernel_session == NULL) {
720 session_unlock(session);
721 continue;
722 }
723
724 /* This is not suppose to be 0 but this is an extra security check */
725 if (session->kernel_session->consumer_fd == 0) {
726 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
727 }
728
729 cds_list_for_each_entry(channel,
730 &session->kernel_session->channel_list.head, list) {
731 if (channel->fd == fd) {
732 DBG("Channel found, updating kernel streams");
733 ret = kernel_open_channel_stream(channel);
734 if (ret < 0) {
735 goto error;
736 }
737
738 /*
739 * Have we already sent fds to the consumer? If yes, it means
740 * that tracing is started so it is safe to send our updated
741 * stream fds.
742 */
743 if (session->kernel_session->consumer_fds_sent == 1) {
744 ret = send_kconsumer_channel_streams(consumer_data,
745 session->kernel_session->consumer_fd, channel,
746 session->uid, session->gid);
747 if (ret < 0) {
748 goto error;
749 }
750 }
751 goto error;
752 }
753 }
754 session_unlock(session);
755 }
756 session_unlock_list();
757 return ret;
758
759 error:
760 session_unlock(session);
761 session_unlock_list();
762 return ret;
763 }
764
765 /*
766 * For each tracing session, update newly registered apps.
767 */
768 static void update_ust_app(int app_sock)
769 {
770 struct ltt_session *sess, *stmp;
771
772 session_lock_list();
773
774 /* For all tracing session(s) */
775 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
776 session_lock(sess);
777 if (sess->ust_session) {
778 ust_app_global_update(sess->ust_session, app_sock);
779 }
780 session_unlock(sess);
781 }
782
783 session_unlock_list();
784 }
785
786 /*
787 * This thread manage event coming from the kernel.
788 *
789 * Features supported in this thread:
790 * -) CPU Hotplug
791 */
792 static void *thread_manage_kernel(void *data)
793 {
794 int ret, i, pollfd, update_poll_flag = 1;
795 uint32_t revents, nb_fd;
796 char tmp;
797 struct lttng_poll_event events;
798
799 DBG("Thread manage kernel started");
800
801 ret = create_thread_poll_set(&events, 2);
802 if (ret < 0) {
803 goto error;
804 }
805
806 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
807 if (ret < 0) {
808 goto error;
809 }
810
811 while (1) {
812 if (update_poll_flag == 1) {
813 /*
814 * Reset number of fd in the poll set. Always 2 since there is the thread
815 * quit pipe and the kernel pipe.
816 */
817 events.nb_fd = 2;
818
819 ret = update_kernel_poll(&events);
820 if (ret < 0) {
821 goto error;
822 }
823 update_poll_flag = 0;
824 }
825
826 nb_fd = LTTNG_POLL_GETNB(&events);
827
828 DBG("Thread kernel polling on %d fds", nb_fd);
829
830 /* Zeroed the poll events */
831 lttng_poll_reset(&events);
832
833 /* Poll infinite value of time */
834 restart:
835 ret = lttng_poll_wait(&events, -1);
836 if (ret < 0) {
837 /*
838 * Restart interrupted system call.
839 */
840 if (errno == EINTR) {
841 goto restart;
842 }
843 goto error;
844 } else if (ret == 0) {
845 /* Should not happen since timeout is infinite */
846 ERR("Return value of poll is 0 with an infinite timeout.\n"
847 "This should not have happened! Continuing...");
848 continue;
849 }
850
851 for (i = 0; i < nb_fd; i++) {
852 /* Fetch once the poll data */
853 revents = LTTNG_POLL_GETEV(&events, i);
854 pollfd = LTTNG_POLL_GETFD(&events, i);
855
856 /* Thread quit pipe has been closed. Killing thread. */
857 ret = check_thread_quit_pipe(pollfd, revents);
858 if (ret) {
859 goto error;
860 }
861
862 /* Check for data on kernel pipe */
863 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
864 ret = read(kernel_poll_pipe[0], &tmp, 1);
865 update_poll_flag = 1;
866 continue;
867 } else {
868 /*
869 * New CPU detected by the kernel. Adding kernel stream to
870 * kernel session and updating the kernel consumer
871 */
872 if (revents & LPOLLIN) {
873 ret = update_kernel_stream(&kconsumer_data, pollfd);
874 if (ret < 0) {
875 continue;
876 }
877 break;
878 /*
879 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
880 * and unregister kernel stream at this point.
881 */
882 }
883 }
884 }
885 }
886
887 error:
888 DBG("Kernel thread dying");
889 close(kernel_poll_pipe[0]);
890 close(kernel_poll_pipe[1]);
891
892 lttng_poll_clean(&events);
893
894 return NULL;
895 }
896
897 /*
898 * This thread manage the consumer error sent back to the session daemon.
899 */
900 static void *thread_manage_consumer(void *data)
901 {
902 int sock = 0, i, ret, pollfd;
903 uint32_t revents, nb_fd;
904 enum lttcomm_return_code code;
905 struct lttng_poll_event events;
906 struct consumer_data *consumer_data = data;
907
908 DBG("[thread] Manage consumer started");
909
910 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
911 if (ret < 0) {
912 goto error;
913 }
914
915 /*
916 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
917 * Nothing more will be added to this poll set.
918 */
919 ret = create_thread_poll_set(&events, 2);
920 if (ret < 0) {
921 goto error;
922 }
923
924 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
925 if (ret < 0) {
926 goto error;
927 }
928
929 nb_fd = LTTNG_POLL_GETNB(&events);
930
931 /* Inifinite blocking call, waiting for transmission */
932 restart:
933 ret = lttng_poll_wait(&events, -1);
934 if (ret < 0) {
935 /*
936 * Restart interrupted system call.
937 */
938 if (errno == EINTR) {
939 goto restart;
940 }
941 goto error;
942 }
943
944 for (i = 0; i < nb_fd; i++) {
945 /* Fetch once the poll data */
946 revents = LTTNG_POLL_GETEV(&events, i);
947 pollfd = LTTNG_POLL_GETFD(&events, i);
948
949 /* Thread quit pipe has been closed. Killing thread. */
950 ret = check_thread_quit_pipe(pollfd, revents);
951 if (ret) {
952 goto error;
953 }
954
955 /* Event on the registration socket */
956 if (pollfd == consumer_data->err_sock) {
957 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
958 ERR("consumer err socket poll error");
959 goto error;
960 }
961 }
962 }
963
964 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
965 if (sock < 0) {
966 goto error;
967 }
968
969 DBG2("Receiving code from consumer err_sock");
970
971 /* Getting status code from kconsumerd */
972 ret = lttcomm_recv_unix_sock(sock, &code,
973 sizeof(enum lttcomm_return_code));
974 if (ret <= 0) {
975 goto error;
976 }
977
978 if (code == CONSUMERD_COMMAND_SOCK_READY) {
979 consumer_data->cmd_sock =
980 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
981 if (consumer_data->cmd_sock < 0) {
982 sem_post(&consumer_data->sem);
983 PERROR("consumer connect");
984 goto error;
985 }
986 /* Signal condition to tell that the kconsumerd is ready */
987 sem_post(&consumer_data->sem);
988 DBG("consumer command socket ready");
989 } else {
990 ERR("consumer error when waiting for SOCK_READY : %s",
991 lttcomm_get_readable_code(-code));
992 goto error;
993 }
994
995 /* Remove the kconsumerd error sock since we've established a connexion */
996 ret = lttng_poll_del(&events, consumer_data->err_sock);
997 if (ret < 0) {
998 goto error;
999 }
1000
1001 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
1002 if (ret < 0) {
1003 goto error;
1004 }
1005
1006 /* Update number of fd */
1007 nb_fd = LTTNG_POLL_GETNB(&events);
1008
1009 /* Inifinite blocking call, waiting for transmission */
1010 restart_poll:
1011 ret = lttng_poll_wait(&events, -1);
1012 if (ret < 0) {
1013 /*
1014 * Restart interrupted system call.
1015 */
1016 if (errno == EINTR) {
1017 goto restart_poll;
1018 }
1019 goto error;
1020 }
1021
1022 for (i = 0; i < nb_fd; i++) {
1023 /* Fetch once the poll data */
1024 revents = LTTNG_POLL_GETEV(&events, i);
1025 pollfd = LTTNG_POLL_GETFD(&events, i);
1026
1027 /* Thread quit pipe has been closed. Killing thread. */
1028 ret = check_thread_quit_pipe(pollfd, revents);
1029 if (ret) {
1030 goto error;
1031 }
1032
1033 /* Event on the kconsumerd socket */
1034 if (pollfd == sock) {
1035 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1036 ERR("consumer err socket second poll error");
1037 goto error;
1038 }
1039 }
1040 }
1041
1042 /* Wait for any kconsumerd error */
1043 ret = lttcomm_recv_unix_sock(sock, &code,
1044 sizeof(enum lttcomm_return_code));
1045 if (ret <= 0) {
1046 ERR("consumer closed the command socket");
1047 goto error;
1048 }
1049
1050 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
1051
1052 error:
1053 DBG("consumer thread dying");
1054 close(consumer_data->err_sock);
1055 close(consumer_data->cmd_sock);
1056 close(sock);
1057
1058 unlink(consumer_data->err_unix_sock_path);
1059 unlink(consumer_data->cmd_unix_sock_path);
1060 consumer_data->pid = 0;
1061
1062 lttng_poll_clean(&events);
1063
1064 return NULL;
1065 }
1066
1067 /*
1068 * This thread manage application communication.
1069 */
1070 static void *thread_manage_apps(void *data)
1071 {
1072 int i, ret, pollfd;
1073 uint32_t revents, nb_fd;
1074 struct ust_command ust_cmd;
1075 struct lttng_poll_event events;
1076
1077 DBG("[thread] Manage application started");
1078
1079 rcu_register_thread();
1080 rcu_thread_online();
1081
1082 ret = create_thread_poll_set(&events, 2);
1083 if (ret < 0) {
1084 goto error;
1085 }
1086
1087 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1088 if (ret < 0) {
1089 goto error;
1090 }
1091
1092 while (1) {
1093 /* Zeroed the events structure */
1094 lttng_poll_reset(&events);
1095
1096 nb_fd = LTTNG_POLL_GETNB(&events);
1097
1098 DBG("Apps thread polling on %d fds", nb_fd);
1099
1100 /* Inifinite blocking call, waiting for transmission */
1101 restart:
1102 ret = lttng_poll_wait(&events, -1);
1103 if (ret < 0) {
1104 /*
1105 * Restart interrupted system call.
1106 */
1107 if (errno == EINTR) {
1108 goto restart;
1109 }
1110 goto error;
1111 }
1112
1113 for (i = 0; i < nb_fd; i++) {
1114 /* Fetch once the poll data */
1115 revents = LTTNG_POLL_GETEV(&events, i);
1116 pollfd = LTTNG_POLL_GETFD(&events, i);
1117
1118 /* Thread quit pipe has been closed. Killing thread. */
1119 ret = check_thread_quit_pipe(pollfd, revents);
1120 if (ret) {
1121 goto error;
1122 }
1123
1124 /* Inspect the apps cmd pipe */
1125 if (pollfd == apps_cmd_pipe[0]) {
1126 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1127 ERR("Apps command pipe error");
1128 goto error;
1129 } else if (revents & LPOLLIN) {
1130 /* Empty pipe */
1131 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1132 if (ret < 0 || ret < sizeof(ust_cmd)) {
1133 perror("read apps cmd pipe");
1134 goto error;
1135 }
1136
1137 /* Register applicaton to the session daemon */
1138 ret = ust_app_register(&ust_cmd.reg_msg,
1139 ust_cmd.sock);
1140 if (ret == -ENOMEM) {
1141 goto error;
1142 } else if (ret < 0) {
1143 break;
1144 }
1145
1146 /*
1147 * Validate UST version compatibility.
1148 */
1149 ret = ust_app_validate_version(ust_cmd.sock);
1150 if (ret >= 0) {
1151 /*
1152 * Add channel(s) and event(s) to newly registered apps
1153 * from lttng global UST domain.
1154 */
1155 update_ust_app(ust_cmd.sock);
1156 }
1157
1158 ret = ust_app_register_done(ust_cmd.sock);
1159 if (ret < 0) {
1160 /*
1161 * If the registration is not possible, we simply
1162 * unregister the apps and continue
1163 */
1164 ust_app_unregister(ust_cmd.sock);
1165 } else {
1166 /*
1167 * We just need here to monitor the close of the UST
1168 * socket and poll set monitor those by default.
1169 * Listen on POLLIN (even if we never expect any
1170 * data) to ensure that hangup wakes us.
1171 */
1172 ret = lttng_poll_add(&events, ust_cmd.sock, LPOLLIN);
1173 if (ret < 0) {
1174 goto error;
1175 }
1176
1177 DBG("Apps with sock %d added to poll set",
1178 ust_cmd.sock);
1179 }
1180
1181 break;
1182 }
1183 } else {
1184 /*
1185 * At this point, we know that a registered application made
1186 * the event at poll_wait.
1187 */
1188 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1189 /* Removing from the poll set */
1190 ret = lttng_poll_del(&events, pollfd);
1191 if (ret < 0) {
1192 goto error;
1193 }
1194
1195 /* Socket closed on remote end. */
1196 ust_app_unregister(pollfd);
1197 break;
1198 }
1199 }
1200 }
1201 }
1202
1203 error:
1204 DBG("Application communication apps dying");
1205 close(apps_cmd_pipe[0]);
1206 close(apps_cmd_pipe[1]);
1207
1208 lttng_poll_clean(&events);
1209
1210 rcu_thread_offline();
1211 rcu_unregister_thread();
1212 return NULL;
1213 }
1214
1215 /*
1216 * Dispatch request from the registration threads to the application
1217 * communication thread.
1218 */
1219 static void *thread_dispatch_ust_registration(void *data)
1220 {
1221 int ret;
1222 struct cds_wfq_node *node;
1223 struct ust_command *ust_cmd = NULL;
1224
1225 DBG("[thread] Dispatch UST command started");
1226
1227 while (!dispatch_thread_exit) {
1228 /* Atomically prepare the queue futex */
1229 futex_nto1_prepare(&ust_cmd_queue.futex);
1230
1231 do {
1232 /* Dequeue command for registration */
1233 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1234 if (node == NULL) {
1235 DBG("Woken up but nothing in the UST command queue");
1236 /* Continue thread execution */
1237 break;
1238 }
1239
1240 ust_cmd = caa_container_of(node, struct ust_command, node);
1241
1242 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1243 " gid:%d sock:%d name:%s (version %d.%d)",
1244 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1245 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1246 ust_cmd->sock, ust_cmd->reg_msg.name,
1247 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1248 /*
1249 * Inform apps thread of the new application registration. This
1250 * call is blocking so we can be assured that the data will be read
1251 * at some point in time or wait to the end of the world :)
1252 */
1253 ret = write(apps_cmd_pipe[1], ust_cmd,
1254 sizeof(struct ust_command));
1255 if (ret < 0) {
1256 perror("write apps cmd pipe");
1257 if (errno == EBADF) {
1258 /*
1259 * We can't inform the application thread to process
1260 * registration. We will exit or else application
1261 * registration will not occur and tracing will never
1262 * start.
1263 */
1264 goto error;
1265 }
1266 }
1267 free(ust_cmd);
1268 } while (node != NULL);
1269
1270 /* Futex wait on queue. Blocking call on futex() */
1271 futex_nto1_wait(&ust_cmd_queue.futex);
1272 }
1273
1274 error:
1275 DBG("Dispatch thread dying");
1276 return NULL;
1277 }
1278
1279 /*
1280 * This thread manage application registration.
1281 */
1282 static void *thread_registration_apps(void *data)
1283 {
1284 int sock = 0, i, ret, pollfd;
1285 uint32_t revents, nb_fd;
1286 struct lttng_poll_event events;
1287 /*
1288 * Get allocated in this thread, enqueued to a global queue, dequeued and
1289 * freed in the manage apps thread.
1290 */
1291 struct ust_command *ust_cmd = NULL;
1292
1293 DBG("[thread] Manage application registration started");
1294
1295 ret = lttcomm_listen_unix_sock(apps_sock);
1296 if (ret < 0) {
1297 goto error;
1298 }
1299
1300 /*
1301 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1302 * more will be added to this poll set.
1303 */
1304 ret = create_thread_poll_set(&events, 2);
1305 if (ret < 0) {
1306 goto error;
1307 }
1308
1309 /* Add the application registration socket */
1310 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1311 if (ret < 0) {
1312 goto error;
1313 }
1314
1315 /* Notify all applications to register */
1316 ret = notify_ust_apps(1);
1317 if (ret < 0) {
1318 ERR("Failed to notify applications or create the wait shared memory.\n"
1319 "Execution continues but there might be problem for already\n"
1320 "running applications that wishes to register.");
1321 }
1322
1323 while (1) {
1324 DBG("Accepting application registration");
1325
1326 nb_fd = LTTNG_POLL_GETNB(&events);
1327
1328 /* Inifinite blocking call, waiting for transmission */
1329 restart:
1330 ret = lttng_poll_wait(&events, -1);
1331 if (ret < 0) {
1332 /*
1333 * Restart interrupted system call.
1334 */
1335 if (errno == EINTR) {
1336 goto restart;
1337 }
1338 goto error;
1339 }
1340
1341 for (i = 0; i < nb_fd; i++) {
1342 /* Fetch once the poll data */
1343 revents = LTTNG_POLL_GETEV(&events, i);
1344 pollfd = LTTNG_POLL_GETFD(&events, i);
1345
1346 /* Thread quit pipe has been closed. Killing thread. */
1347 ret = check_thread_quit_pipe(pollfd, revents);
1348 if (ret) {
1349 goto error;
1350 }
1351
1352 /* Event on the registration socket */
1353 if (pollfd == apps_sock) {
1354 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1355 ERR("Register apps socket poll error");
1356 goto error;
1357 } else if (revents & LPOLLIN) {
1358 sock = lttcomm_accept_unix_sock(apps_sock);
1359 if (sock < 0) {
1360 goto error;
1361 }
1362
1363 /* Create UST registration command for enqueuing */
1364 ust_cmd = zmalloc(sizeof(struct ust_command));
1365 if (ust_cmd == NULL) {
1366 perror("ust command zmalloc");
1367 goto error;
1368 }
1369
1370 /*
1371 * Using message-based transmissions to ensure we don't
1372 * have to deal with partially received messages.
1373 */
1374 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1375 sizeof(struct ust_register_msg));
1376 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1377 if (ret < 0) {
1378 perror("lttcomm_recv_unix_sock register apps");
1379 } else {
1380 ERR("Wrong size received on apps register");
1381 }
1382 free(ust_cmd);
1383 close(sock);
1384 continue;
1385 }
1386
1387 ust_cmd->sock = sock;
1388
1389 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1390 " gid:%d sock:%d name:%s (version %d.%d)",
1391 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1392 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1393 ust_cmd->sock, ust_cmd->reg_msg.name,
1394 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1395
1396 /*
1397 * Lock free enqueue the registration request. The red pill
1398 * has been taken! This apps will be part of the *system*.
1399 */
1400 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1401
1402 /*
1403 * Wake the registration queue futex. Implicit memory
1404 * barrier with the exchange in cds_wfq_enqueue.
1405 */
1406 futex_nto1_wake(&ust_cmd_queue.futex);
1407 }
1408 }
1409 }
1410 }
1411
1412 error:
1413 DBG("UST Registration thread dying");
1414
1415 /* Notify that the registration thread is gone */
1416 notify_ust_apps(0);
1417
1418 close(apps_sock);
1419 close(sock);
1420 unlink(apps_unix_sock_path);
1421
1422 lttng_poll_clean(&events);
1423
1424 return NULL;
1425 }
1426
1427 /*
1428 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1429 * exec or it will fails.
1430 */
1431 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1432 {
1433 int ret;
1434 struct timespec timeout;
1435
1436 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1437 timeout.tv_nsec = 0;
1438
1439 /* Setup semaphore */
1440 ret = sem_init(&consumer_data->sem, 0, 0);
1441 if (ret < 0) {
1442 PERROR("sem_init consumer semaphore");
1443 goto error;
1444 }
1445
1446 ret = pthread_create(&consumer_data->thread, NULL,
1447 thread_manage_consumer, consumer_data);
1448 if (ret != 0) {
1449 PERROR("pthread_create consumer");
1450 ret = -1;
1451 goto error;
1452 }
1453
1454 /* Get time for sem_timedwait absolute timeout */
1455 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1456 if (ret < 0) {
1457 PERROR("clock_gettime spawn consumer");
1458 /* Infinite wait for the kconsumerd thread to be ready */
1459 ret = sem_wait(&consumer_data->sem);
1460 } else {
1461 /* Normal timeout if the gettime was successful */
1462 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1463 ret = sem_timedwait(&consumer_data->sem, &timeout);
1464 }
1465
1466 if (ret < 0) {
1467 if (errno == ETIMEDOUT) {
1468 /*
1469 * Call has timed out so we kill the kconsumerd_thread and return
1470 * an error.
1471 */
1472 ERR("The consumer thread was never ready. Killing it");
1473 ret = pthread_cancel(consumer_data->thread);
1474 if (ret < 0) {
1475 PERROR("pthread_cancel consumer thread");
1476 }
1477 } else {
1478 PERROR("semaphore wait failed consumer thread");
1479 }
1480 goto error;
1481 }
1482
1483 pthread_mutex_lock(&consumer_data->pid_mutex);
1484 if (consumer_data->pid == 0) {
1485 ERR("Kconsumerd did not start");
1486 pthread_mutex_unlock(&consumer_data->pid_mutex);
1487 goto error;
1488 }
1489 pthread_mutex_unlock(&consumer_data->pid_mutex);
1490
1491 return 0;
1492
1493 error:
1494 return ret;
1495 }
1496
1497 /*
1498 * Join consumer thread
1499 */
1500 static int join_consumer_thread(struct consumer_data *consumer_data)
1501 {
1502 void *status;
1503 int ret;
1504
1505 if (consumer_data->pid != 0) {
1506 ret = kill(consumer_data->pid, SIGTERM);
1507 if (ret) {
1508 ERR("Error killing consumer daemon");
1509 return ret;
1510 }
1511 return pthread_join(consumer_data->thread, &status);
1512 } else {
1513 return 0;
1514 }
1515 }
1516
1517 /*
1518 * Fork and exec a consumer daemon (consumerd).
1519 *
1520 * Return pid if successful else -1.
1521 */
1522 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1523 {
1524 int ret;
1525 pid_t pid;
1526 const char *consumer_to_use;
1527 const char *verbosity;
1528 struct stat st;
1529
1530 DBG("Spawning consumerd");
1531
1532 pid = fork();
1533 if (pid == 0) {
1534 /*
1535 * Exec consumerd.
1536 */
1537 if (opt_verbose_consumer) {
1538 verbosity = "--verbose";
1539 } else {
1540 verbosity = "--quiet";
1541 }
1542 switch (consumer_data->type) {
1543 case LTTNG_CONSUMER_KERNEL:
1544 /*
1545 * Find out which consumerd to execute. We will first try the
1546 * 64-bit path, then the sessiond's installation directory, and
1547 * fallback on the 32-bit one,
1548 */
1549 DBG3("Looking for a kernel consumer at these locations:");
1550 DBG3(" 1) %s", consumerd64_bin);
1551 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, CONSUMERD_FILE);
1552 DBG3(" 3) %s", consumerd32_bin);
1553 if (stat(consumerd64_bin, &st) == 0) {
1554 DBG3("Found location #1");
1555 consumer_to_use = consumerd64_bin;
1556 } else if (stat(INSTALL_BIN_PATH "/" CONSUMERD_FILE, &st) == 0) {
1557 DBG3("Found location #2");
1558 consumer_to_use = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
1559 } else if (stat(consumerd32_bin, &st) == 0) {
1560 DBG3("Found location #3");
1561 consumer_to_use = consumerd32_bin;
1562 } else {
1563 DBG("Could not find any valid consumerd executable");
1564 break;
1565 }
1566 DBG("Using kernel consumer at: %s", consumer_to_use);
1567 execl(consumer_to_use,
1568 "lttng-consumerd", verbosity, "-k",
1569 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1570 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1571 NULL);
1572 break;
1573 case LTTNG_CONSUMER64_UST:
1574 {
1575 char *tmpnew = NULL;
1576
1577 if (consumerd64_libdir[0] != '\0') {
1578 char *tmp;
1579 size_t tmplen;
1580
1581 tmp = getenv("LD_LIBRARY_PATH");
1582 if (!tmp) {
1583 tmp = "";
1584 }
1585 tmplen = strlen("LD_LIBRARY_PATH=")
1586 + strlen(consumerd64_libdir) + 1 /* : */ + strlen(tmp);
1587 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1588 if (!tmpnew) {
1589 ret = -ENOMEM;
1590 goto error;
1591 }
1592 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1593 strcat(tmpnew, consumerd64_libdir);
1594 if (tmp[0] != '\0') {
1595 strcat(tmpnew, ":");
1596 strcat(tmpnew, tmp);
1597 }
1598 ret = putenv(tmpnew);
1599 if (ret) {
1600 ret = -errno;
1601 goto error;
1602 }
1603 }
1604 DBG("Using 64-bit UST consumer at: %s", consumerd64_bin);
1605 ret = execl(consumerd64_bin, "lttng-consumerd", verbosity, "-u",
1606 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1607 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1608 NULL);
1609 if (consumerd64_libdir[0] != '\0') {
1610 free(tmpnew);
1611 }
1612 if (ret) {
1613 goto error;
1614 }
1615 break;
1616 }
1617 case LTTNG_CONSUMER32_UST:
1618 {
1619 char *tmpnew = NULL;
1620
1621 if (consumerd32_libdir[0] != '\0') {
1622 char *tmp;
1623 size_t tmplen;
1624
1625 tmp = getenv("LD_LIBRARY_PATH");
1626 if (!tmp) {
1627 tmp = "";
1628 }
1629 tmplen = strlen("LD_LIBRARY_PATH=")
1630 + strlen(consumerd32_libdir) + 1 /* : */ + strlen(tmp);
1631 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1632 if (!tmpnew) {
1633 ret = -ENOMEM;
1634 goto error;
1635 }
1636 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1637 strcat(tmpnew, consumerd32_libdir);
1638 if (tmp[0] != '\0') {
1639 strcat(tmpnew, ":");
1640 strcat(tmpnew, tmp);
1641 }
1642 ret = putenv(tmpnew);
1643 if (ret) {
1644 ret = -errno;
1645 goto error;
1646 }
1647 }
1648 DBG("Using 32-bit UST consumer at: %s", consumerd32_bin);
1649 ret = execl(consumerd32_bin, "lttng-consumerd", verbosity, "-u",
1650 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1651 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1652 NULL);
1653 if (consumerd32_libdir[0] != '\0') {
1654 free(tmpnew);
1655 }
1656 if (ret) {
1657 goto error;
1658 }
1659 break;
1660 }
1661 default:
1662 perror("unknown consumer type");
1663 exit(EXIT_FAILURE);
1664 }
1665 if (errno != 0) {
1666 perror("kernel start consumer exec");
1667 }
1668 exit(EXIT_FAILURE);
1669 } else if (pid > 0) {
1670 ret = pid;
1671 } else {
1672 perror("start consumer fork");
1673 ret = -errno;
1674 }
1675 error:
1676 return ret;
1677 }
1678
1679 /*
1680 * Spawn the consumerd daemon and session daemon thread.
1681 */
1682 static int start_consumerd(struct consumer_data *consumer_data)
1683 {
1684 int ret;
1685
1686 pthread_mutex_lock(&consumer_data->pid_mutex);
1687 if (consumer_data->pid != 0) {
1688 pthread_mutex_unlock(&consumer_data->pid_mutex);
1689 goto end;
1690 }
1691
1692 ret = spawn_consumerd(consumer_data);
1693 if (ret < 0) {
1694 ERR("Spawning consumerd failed");
1695 pthread_mutex_unlock(&consumer_data->pid_mutex);
1696 goto error;
1697 }
1698
1699 /* Setting up the consumer_data pid */
1700 consumer_data->pid = ret;
1701 DBG2("Consumer pid %d", consumer_data->pid);
1702 pthread_mutex_unlock(&consumer_data->pid_mutex);
1703
1704 DBG2("Spawning consumer control thread");
1705 ret = spawn_consumer_thread(consumer_data);
1706 if (ret < 0) {
1707 ERR("Fatal error spawning consumer control thread");
1708 goto error;
1709 }
1710
1711 end:
1712 return 0;
1713
1714 error:
1715 return ret;
1716 }
1717
1718 /*
1719 * Check version of the lttng-modules.
1720 */
1721 static int validate_lttng_modules_version(void)
1722 {
1723 return kernel_validate_version(kernel_tracer_fd);
1724 }
1725
1726 /*
1727 * Setup necessary data for kernel tracer action.
1728 */
1729 static int init_kernel_tracer(void)
1730 {
1731 int ret;
1732
1733 /* Modprobe lttng kernel modules */
1734 ret = modprobe_lttng_control();
1735 if (ret < 0) {
1736 goto error;
1737 }
1738
1739 /* Open debugfs lttng */
1740 kernel_tracer_fd = open(module_proc_lttng, O_RDWR);
1741 if (kernel_tracer_fd < 0) {
1742 DBG("Failed to open %s", module_proc_lttng);
1743 ret = -1;
1744 goto error_open;
1745 }
1746
1747 /* Validate kernel version */
1748 ret = validate_lttng_modules_version();
1749 if (ret < 0) {
1750 goto error_version;
1751 }
1752
1753 ret = modprobe_lttng_data();
1754 if (ret < 0) {
1755 goto error_modules;
1756 }
1757
1758 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1759 return 0;
1760
1761 error_version:
1762 modprobe_remove_lttng_control();
1763 close(kernel_tracer_fd);
1764 kernel_tracer_fd = 0;
1765 return LTTCOMM_KERN_VERSION;
1766
1767 error_modules:
1768 close(kernel_tracer_fd);
1769
1770 error_open:
1771 modprobe_remove_lttng_control();
1772
1773 error:
1774 WARN("No kernel tracer available");
1775 kernel_tracer_fd = 0;
1776 return LTTCOMM_KERN_NA;
1777 }
1778
1779 /*
1780 * Init tracing by creating trace directory and sending fds kernel consumer.
1781 */
1782 static int init_kernel_tracing(struct ltt_kernel_session *session)
1783 {
1784 int ret = 0;
1785
1786 if (session->consumer_fds_sent == 0) {
1787 /*
1788 * Assign default kernel consumer socket if no consumer assigned to the
1789 * kernel session. At this point, it's NOT suppose to be 0 but this is
1790 * an extra security check.
1791 */
1792 if (session->consumer_fd == 0) {
1793 session->consumer_fd = kconsumer_data.cmd_sock;
1794 }
1795
1796 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1797 if (ret < 0) {
1798 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1799 goto error;
1800 }
1801
1802 session->consumer_fds_sent = 1;
1803 }
1804
1805 error:
1806 return ret;
1807 }
1808
1809 /*
1810 * Create an UST session and add it to the session ust list.
1811 */
1812 static int create_ust_session(struct ltt_session *session,
1813 struct lttng_domain *domain)
1814 {
1815 struct ltt_ust_session *lus = NULL;
1816 int ret;
1817
1818 switch (domain->type) {
1819 case LTTNG_DOMAIN_UST:
1820 break;
1821 default:
1822 ret = LTTCOMM_UNKNOWN_DOMAIN;
1823 goto error;
1824 }
1825
1826 DBG("Creating UST session");
1827
1828 lus = trace_ust_create_session(session->path, session->id, domain);
1829 if (lus == NULL) {
1830 ret = LTTCOMM_UST_SESS_FAIL;
1831 goto error;
1832 }
1833
1834 ret = run_as_mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1835 session->uid, session->gid);
1836 if (ret < 0) {
1837 if (ret != -EEXIST) {
1838 ERR("Trace directory creation error");
1839 ret = LTTCOMM_UST_SESS_FAIL;
1840 goto error;
1841 }
1842 }
1843
1844 /* The domain type dictate different actions on session creation */
1845 switch (domain->type) {
1846 case LTTNG_DOMAIN_UST:
1847 /* No ustctl for the global UST domain */
1848 break;
1849 default:
1850 ERR("Unknown UST domain on create session %d", domain->type);
1851 goto error;
1852 }
1853 lus->uid = session->uid;
1854 lus->gid = session->gid;
1855 session->ust_session = lus;
1856
1857 return LTTCOMM_OK;
1858
1859 error:
1860 free(lus);
1861 return ret;
1862 }
1863
1864 /*
1865 * Create a kernel tracer session then create the default channel.
1866 */
1867 static int create_kernel_session(struct ltt_session *session)
1868 {
1869 int ret;
1870
1871 DBG("Creating kernel session");
1872
1873 ret = kernel_create_session(session, kernel_tracer_fd);
1874 if (ret < 0) {
1875 ret = LTTCOMM_KERN_SESS_FAIL;
1876 goto error;
1877 }
1878
1879 /* Set kernel consumer socket fd */
1880 if (kconsumer_data.cmd_sock) {
1881 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1882 }
1883
1884 ret = run_as_mkdir_recursive(session->kernel_session->trace_path,
1885 S_IRWXU | S_IRWXG, session->uid, session->gid);
1886 if (ret < 0) {
1887 if (ret != -EEXIST) {
1888 ERR("Trace directory creation error");
1889 goto error;
1890 }
1891 }
1892 session->kernel_session->uid = session->uid;
1893 session->kernel_session->gid = session->gid;
1894
1895 error:
1896 return ret;
1897 }
1898
1899 /*
1900 * Check if the UID or GID match the session. Root user has access to all
1901 * sessions.
1902 */
1903 static int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
1904 {
1905 if (uid != session->uid && gid != session->gid && uid != 0) {
1906 return 0;
1907 } else {
1908 return 1;
1909 }
1910 }
1911
1912 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
1913 {
1914 unsigned int i = 0;
1915 struct ltt_session *session;
1916
1917 DBG("Counting number of available session for UID %d GID %d",
1918 uid, gid);
1919 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1920 /*
1921 * Only list the sessions the user can control.
1922 */
1923 if (!session_access_ok(session, uid, gid)) {
1924 continue;
1925 }
1926 i++;
1927 }
1928 return i;
1929 }
1930
1931 /*
1932 * Using the session list, filled a lttng_session array to send back to the
1933 * client for session listing.
1934 *
1935 * The session list lock MUST be acquired before calling this function. Use
1936 * session_lock_list() and session_unlock_list().
1937 */
1938 static void list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
1939 gid_t gid)
1940 {
1941 unsigned int i = 0;
1942 struct ltt_session *session;
1943
1944 DBG("Getting all available session for UID %d GID %d",
1945 uid, gid);
1946 /*
1947 * Iterate over session list and append data after the control struct in
1948 * the buffer.
1949 */
1950 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1951 /*
1952 * Only list the sessions the user can control.
1953 */
1954 if (!session_access_ok(session, uid, gid)) {
1955 continue;
1956 }
1957 strncpy(sessions[i].path, session->path, PATH_MAX);
1958 sessions[i].path[PATH_MAX - 1] = '\0';
1959 strncpy(sessions[i].name, session->name, NAME_MAX);
1960 sessions[i].name[NAME_MAX - 1] = '\0';
1961 sessions[i].enabled = session->enabled;
1962 i++;
1963 }
1964 }
1965
1966 /*
1967 * Fill lttng_channel array of all channels.
1968 */
1969 static void list_lttng_channels(int domain, struct ltt_session *session,
1970 struct lttng_channel *channels)
1971 {
1972 int i = 0;
1973 struct ltt_kernel_channel *kchan;
1974
1975 DBG("Listing channels for session %s", session->name);
1976
1977 switch (domain) {
1978 case LTTNG_DOMAIN_KERNEL:
1979 /* Kernel channels */
1980 if (session->kernel_session != NULL) {
1981 cds_list_for_each_entry(kchan,
1982 &session->kernel_session->channel_list.head, list) {
1983 /* Copy lttng_channel struct to array */
1984 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1985 channels[i].enabled = kchan->enabled;
1986 i++;
1987 }
1988 }
1989 break;
1990 case LTTNG_DOMAIN_UST:
1991 {
1992 struct lttng_ht_iter iter;
1993 struct ltt_ust_channel *uchan;
1994
1995 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
1996 &iter.iter, uchan, node.node) {
1997 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
1998 channels[i].attr.overwrite = uchan->attr.overwrite;
1999 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
2000 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
2001 channels[i].attr.switch_timer_interval =
2002 uchan->attr.switch_timer_interval;
2003 channels[i].attr.read_timer_interval =
2004 uchan->attr.read_timer_interval;
2005 channels[i].enabled = uchan->enabled;
2006 switch (uchan->attr.output) {
2007 case LTTNG_UST_MMAP:
2008 default:
2009 channels[i].attr.output = LTTNG_EVENT_MMAP;
2010 break;
2011 }
2012 i++;
2013 }
2014 break;
2015 }
2016 default:
2017 break;
2018 }
2019 }
2020
2021 /*
2022 * Create a list of ust global domain events.
2023 */
2024 static int list_lttng_ust_global_events(char *channel_name,
2025 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
2026 {
2027 int i = 0, ret = 0;
2028 unsigned int nb_event = 0;
2029 struct lttng_ht_iter iter;
2030 struct lttng_ht_node_str *node;
2031 struct ltt_ust_channel *uchan;
2032 struct ltt_ust_event *uevent;
2033 struct lttng_event *tmp;
2034
2035 DBG("Listing UST global events for channel %s", channel_name);
2036
2037 rcu_read_lock();
2038
2039 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
2040 node = lttng_ht_iter_get_node_str(&iter);
2041 if (node == NULL) {
2042 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
2043 goto error;
2044 }
2045
2046 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
2047
2048 nb_event += lttng_ht_get_count(uchan->events);
2049
2050 if (nb_event == 0) {
2051 ret = nb_event;
2052 goto error;
2053 }
2054
2055 DBG3("Listing UST global %d events", nb_event);
2056
2057 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
2058 if (tmp == NULL) {
2059 ret = -LTTCOMM_FATAL;
2060 goto error;
2061 }
2062
2063 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
2064 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
2065 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2066 tmp[i].enabled = uevent->enabled;
2067 switch (uevent->attr.instrumentation) {
2068 case LTTNG_UST_TRACEPOINT:
2069 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
2070 break;
2071 case LTTNG_UST_PROBE:
2072 tmp[i].type = LTTNG_EVENT_PROBE;
2073 break;
2074 case LTTNG_UST_FUNCTION:
2075 tmp[i].type = LTTNG_EVENT_FUNCTION;
2076 break;
2077 }
2078 tmp[i].loglevel = uevent->attr.loglevel;
2079 switch (uevent->attr.loglevel_type) {
2080 case LTTNG_UST_LOGLEVEL_ALL:
2081 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2082 break;
2083 case LTTNG_UST_LOGLEVEL_RANGE:
2084 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
2085 break;
2086 case LTTNG_UST_LOGLEVEL_SINGLE:
2087 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
2088 break;
2089 }
2090 i++;
2091 }
2092
2093 ret = nb_event;
2094 *events = tmp;
2095
2096 error:
2097 rcu_read_unlock();
2098 return ret;
2099 }
2100
2101 /*
2102 * Fill lttng_event array of all kernel events in the channel.
2103 */
2104 static int list_lttng_kernel_events(char *channel_name,
2105 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
2106 {
2107 int i = 0, ret;
2108 unsigned int nb_event;
2109 struct ltt_kernel_event *event;
2110 struct ltt_kernel_channel *kchan;
2111
2112 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
2113 if (kchan == NULL) {
2114 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2115 goto error;
2116 }
2117
2118 nb_event = kchan->event_count;
2119
2120 DBG("Listing events for channel %s", kchan->channel->name);
2121
2122 if (nb_event == 0) {
2123 ret = nb_event;
2124 goto error;
2125 }
2126
2127 *events = zmalloc(nb_event * sizeof(struct lttng_event));
2128 if (*events == NULL) {
2129 ret = LTTCOMM_FATAL;
2130 goto error;
2131 }
2132
2133 /* Kernel channels */
2134 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
2135 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
2136 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2137 (*events)[i].enabled = event->enabled;
2138 switch (event->event->instrumentation) {
2139 case LTTNG_KERNEL_TRACEPOINT:
2140 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
2141 break;
2142 case LTTNG_KERNEL_KPROBE:
2143 case LTTNG_KERNEL_KRETPROBE:
2144 (*events)[i].type = LTTNG_EVENT_PROBE;
2145 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
2146 sizeof(struct lttng_kernel_kprobe));
2147 break;
2148 case LTTNG_KERNEL_FUNCTION:
2149 (*events)[i].type = LTTNG_EVENT_FUNCTION;
2150 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
2151 sizeof(struct lttng_kernel_function));
2152 break;
2153 case LTTNG_KERNEL_NOOP:
2154 (*events)[i].type = LTTNG_EVENT_NOOP;
2155 break;
2156 case LTTNG_KERNEL_SYSCALL:
2157 (*events)[i].type = LTTNG_EVENT_SYSCALL;
2158 break;
2159 case LTTNG_KERNEL_ALL:
2160 assert(0);
2161 break;
2162 }
2163 i++;
2164 }
2165
2166 return nb_event;
2167
2168 error:
2169 return ret;
2170 }
2171
2172 /*
2173 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2174 */
2175 static int cmd_disable_channel(struct ltt_session *session,
2176 int domain, char *channel_name)
2177 {
2178 int ret;
2179 struct ltt_ust_session *usess;
2180
2181 usess = session->ust_session;
2182
2183 switch (domain) {
2184 case LTTNG_DOMAIN_KERNEL:
2185 {
2186 ret = channel_kernel_disable(session->kernel_session,
2187 channel_name);
2188 if (ret != LTTCOMM_OK) {
2189 goto error;
2190 }
2191
2192 kernel_wait_quiescent(kernel_tracer_fd);
2193 break;
2194 }
2195 case LTTNG_DOMAIN_UST:
2196 {
2197 struct ltt_ust_channel *uchan;
2198 struct lttng_ht *chan_ht;
2199
2200 chan_ht = usess->domain_global.channels;
2201
2202 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
2203 if (uchan == NULL) {
2204 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2205 goto error;
2206 }
2207
2208 ret = channel_ust_disable(usess, domain, uchan);
2209 if (ret != LTTCOMM_OK) {
2210 goto error;
2211 }
2212 break;
2213 }
2214 #if 0
2215 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2216 case LTTNG_DOMAIN_UST_EXEC_NAME:
2217 case LTTNG_DOMAIN_UST_PID:
2218 #endif
2219 default:
2220 ret = LTTCOMM_UNKNOWN_DOMAIN;
2221 goto error;
2222 }
2223
2224 ret = LTTCOMM_OK;
2225
2226 error:
2227 return ret;
2228 }
2229
2230 /*
2231 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2232 */
2233 static int cmd_enable_channel(struct ltt_session *session,
2234 int domain, struct lttng_channel *attr)
2235 {
2236 int ret;
2237 struct ltt_ust_session *usess = session->ust_session;
2238 struct lttng_ht *chan_ht;
2239
2240 DBG("Enabling channel %s for session %s", attr->name, session->name);
2241
2242 switch (domain) {
2243 case LTTNG_DOMAIN_KERNEL:
2244 {
2245 struct ltt_kernel_channel *kchan;
2246
2247 kchan = trace_kernel_get_channel_by_name(attr->name,
2248 session->kernel_session);
2249 if (kchan == NULL) {
2250 ret = channel_kernel_create(session->kernel_session,
2251 attr, kernel_poll_pipe[1]);
2252 } else {
2253 ret = channel_kernel_enable(session->kernel_session, kchan);
2254 }
2255
2256 if (ret != LTTCOMM_OK) {
2257 goto error;
2258 }
2259
2260 kernel_wait_quiescent(kernel_tracer_fd);
2261 break;
2262 }
2263 case LTTNG_DOMAIN_UST:
2264 {
2265 struct ltt_ust_channel *uchan;
2266
2267 chan_ht = usess->domain_global.channels;
2268
2269 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
2270 if (uchan == NULL) {
2271 ret = channel_ust_create(usess, domain, attr);
2272 } else {
2273 ret = channel_ust_enable(usess, domain, uchan);
2274 }
2275 break;
2276 }
2277 #if 0
2278 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2279 case LTTNG_DOMAIN_UST_EXEC_NAME:
2280 case LTTNG_DOMAIN_UST_PID:
2281 #endif
2282 default:
2283 ret = LTTCOMM_UNKNOWN_DOMAIN;
2284 goto error;
2285 }
2286
2287 error:
2288 return ret;
2289 }
2290
2291 /*
2292 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2293 */
2294 static int cmd_disable_event(struct ltt_session *session, int domain,
2295 char *channel_name, char *event_name)
2296 {
2297 int ret;
2298
2299 switch (domain) {
2300 case LTTNG_DOMAIN_KERNEL:
2301 {
2302 struct ltt_kernel_channel *kchan;
2303 struct ltt_kernel_session *ksess;
2304
2305 ksess = session->kernel_session;
2306
2307 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2308 if (kchan == NULL) {
2309 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2310 goto error;
2311 }
2312
2313 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
2314 if (ret != LTTCOMM_OK) {
2315 goto error;
2316 }
2317
2318 kernel_wait_quiescent(kernel_tracer_fd);
2319 break;
2320 }
2321 case LTTNG_DOMAIN_UST:
2322 {
2323 struct ltt_ust_channel *uchan;
2324 struct ltt_ust_session *usess;
2325
2326 usess = session->ust_session;
2327
2328 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2329 channel_name);
2330 if (uchan == NULL) {
2331 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2332 goto error;
2333 }
2334
2335 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
2336 if (ret != LTTCOMM_OK) {
2337 goto error;
2338 }
2339
2340 DBG3("Disable UST event %s in channel %s completed", event_name,
2341 channel_name);
2342 break;
2343 }
2344 #if 0
2345 case LTTNG_DOMAIN_UST_EXEC_NAME:
2346 case LTTNG_DOMAIN_UST_PID:
2347 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2348 #endif
2349 default:
2350 ret = LTTCOMM_UND;
2351 goto error;
2352 }
2353
2354 ret = LTTCOMM_OK;
2355
2356 error:
2357 return ret;
2358 }
2359
2360 /*
2361 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2362 */
2363 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2364 char *channel_name)
2365 {
2366 int ret;
2367
2368 switch (domain) {
2369 case LTTNG_DOMAIN_KERNEL:
2370 {
2371 struct ltt_kernel_session *ksess;
2372 struct ltt_kernel_channel *kchan;
2373
2374 ksess = session->kernel_session;
2375
2376 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2377 if (kchan == NULL) {
2378 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2379 goto error;
2380 }
2381
2382 ret = event_kernel_disable_all(ksess, kchan);
2383 if (ret != LTTCOMM_OK) {
2384 goto error;
2385 }
2386
2387 kernel_wait_quiescent(kernel_tracer_fd);
2388 break;
2389 }
2390 case LTTNG_DOMAIN_UST:
2391 {
2392 struct ltt_ust_session *usess;
2393 struct ltt_ust_channel *uchan;
2394
2395 usess = session->ust_session;
2396
2397 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2398 channel_name);
2399 if (uchan == NULL) {
2400 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2401 goto error;
2402 }
2403
2404 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
2405 if (ret != 0) {
2406 goto error;
2407 }
2408
2409 DBG3("Disable all UST events in channel %s completed", channel_name);
2410
2411 break;
2412 }
2413 #if 0
2414 case LTTNG_DOMAIN_UST_EXEC_NAME:
2415 case LTTNG_DOMAIN_UST_PID:
2416 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2417 #endif
2418 default:
2419 ret = LTTCOMM_UND;
2420 goto error;
2421 }
2422
2423 ret = LTTCOMM_OK;
2424
2425 error:
2426 return ret;
2427 }
2428
2429 /*
2430 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2431 */
2432 static int cmd_add_context(struct ltt_session *session, int domain,
2433 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2434 {
2435 int ret;
2436
2437 switch (domain) {
2438 case LTTNG_DOMAIN_KERNEL:
2439 /* Add kernel context to kernel tracer */
2440 ret = context_kernel_add(session->kernel_session, ctx,
2441 event_name, channel_name);
2442 if (ret != LTTCOMM_OK) {
2443 goto error;
2444 }
2445 break;
2446 case LTTNG_DOMAIN_UST:
2447 {
2448 struct ltt_ust_session *usess = session->ust_session;
2449
2450 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
2451 if (ret != LTTCOMM_OK) {
2452 goto error;
2453 }
2454 break;
2455 }
2456 #if 0
2457 case LTTNG_DOMAIN_UST_EXEC_NAME:
2458 case LTTNG_DOMAIN_UST_PID:
2459 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2460 #endif
2461 default:
2462 ret = LTTCOMM_UND;
2463 goto error;
2464 }
2465
2466 ret = LTTCOMM_OK;
2467
2468 error:
2469 return ret;
2470 }
2471
2472 /*
2473 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2474 */
2475 static int cmd_enable_event(struct ltt_session *session, int domain,
2476 char *channel_name, struct lttng_event *event)
2477 {
2478 int ret;
2479 struct lttng_channel *attr;
2480 struct ltt_ust_session *usess = session->ust_session;
2481
2482 switch (domain) {
2483 case LTTNG_DOMAIN_KERNEL:
2484 {
2485 struct ltt_kernel_channel *kchan;
2486
2487 kchan = trace_kernel_get_channel_by_name(channel_name,
2488 session->kernel_session);
2489 if (kchan == NULL) {
2490 attr = channel_new_default_attr(domain);
2491 if (attr == NULL) {
2492 ret = LTTCOMM_FATAL;
2493 goto error;
2494 }
2495 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2496
2497 /* This call will notify the kernel thread */
2498 ret = channel_kernel_create(session->kernel_session,
2499 attr, kernel_poll_pipe[1]);
2500 if (ret != LTTCOMM_OK) {
2501 free(attr);
2502 goto error;
2503 }
2504 free(attr);
2505 }
2506
2507 /* Get the newly created kernel channel pointer */
2508 kchan = trace_kernel_get_channel_by_name(channel_name,
2509 session->kernel_session);
2510 if (kchan == NULL) {
2511 /* This sould not happen... */
2512 ret = LTTCOMM_FATAL;
2513 goto error;
2514 }
2515
2516 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2517 event);
2518 if (ret != LTTCOMM_OK) {
2519 goto error;
2520 }
2521
2522 kernel_wait_quiescent(kernel_tracer_fd);
2523 break;
2524 }
2525 case LTTNG_DOMAIN_UST:
2526 {
2527 struct lttng_channel *attr;
2528 struct ltt_ust_channel *uchan;
2529
2530 /* Get channel from global UST domain */
2531 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2532 channel_name);
2533 if (uchan == NULL) {
2534 /* Create default channel */
2535 attr = channel_new_default_attr(domain);
2536 if (attr == NULL) {
2537 ret = LTTCOMM_FATAL;
2538 goto error;
2539 }
2540 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2541 attr->name[NAME_MAX - 1] = '\0';
2542
2543 ret = channel_ust_create(usess, domain, attr);
2544 if (ret != LTTCOMM_OK) {
2545 free(attr);
2546 goto error;
2547 }
2548 free(attr);
2549
2550 /* Get the newly created channel reference back */
2551 uchan = trace_ust_find_channel_by_name(
2552 usess->domain_global.channels, channel_name);
2553 if (uchan == NULL) {
2554 /* Something is really wrong */
2555 ret = LTTCOMM_FATAL;
2556 goto error;
2557 }
2558 }
2559
2560 /* At this point, the session and channel exist on the tracer */
2561 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
2562 if (ret != LTTCOMM_OK) {
2563 goto error;
2564 }
2565 break;
2566 }
2567 #if 0
2568 case LTTNG_DOMAIN_UST_EXEC_NAME:
2569 case LTTNG_DOMAIN_UST_PID:
2570 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2571 #endif
2572 default:
2573 ret = LTTCOMM_UND;
2574 goto error;
2575 }
2576
2577 ret = LTTCOMM_OK;
2578
2579 error:
2580 return ret;
2581 }
2582
2583 /*
2584 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2585 */
2586 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2587 char *channel_name, int event_type)
2588 {
2589 int ret;
2590 struct ltt_kernel_channel *kchan;
2591
2592 switch (domain) {
2593 case LTTNG_DOMAIN_KERNEL:
2594 kchan = trace_kernel_get_channel_by_name(channel_name,
2595 session->kernel_session);
2596 if (kchan == NULL) {
2597 /* This call will notify the kernel thread */
2598 ret = channel_kernel_create(session->kernel_session, NULL,
2599 kernel_poll_pipe[1]);
2600 if (ret != LTTCOMM_OK) {
2601 goto error;
2602 }
2603
2604 /* Get the newly created kernel channel pointer */
2605 kchan = trace_kernel_get_channel_by_name(channel_name,
2606 session->kernel_session);
2607 if (kchan == NULL) {
2608 /* This sould not happen... */
2609 ret = LTTCOMM_FATAL;
2610 goto error;
2611 }
2612
2613 }
2614
2615 switch (event_type) {
2616 case LTTNG_EVENT_SYSCALL:
2617 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2618 kchan, kernel_tracer_fd);
2619 break;
2620 case LTTNG_EVENT_TRACEPOINT:
2621 /*
2622 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2623 * events already registered to the channel.
2624 */
2625 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2626 kchan, kernel_tracer_fd);
2627 break;
2628 case LTTNG_EVENT_ALL:
2629 /* Enable syscalls and tracepoints */
2630 ret = event_kernel_enable_all(session->kernel_session,
2631 kchan, kernel_tracer_fd);
2632 break;
2633 default:
2634 ret = LTTCOMM_KERN_ENABLE_FAIL;
2635 goto error;
2636 }
2637
2638 /* Manage return value */
2639 if (ret != LTTCOMM_OK) {
2640 goto error;
2641 }
2642
2643 kernel_wait_quiescent(kernel_tracer_fd);
2644 break;
2645 case LTTNG_DOMAIN_UST:
2646 {
2647 struct lttng_channel *attr;
2648 struct ltt_ust_channel *uchan;
2649 struct ltt_ust_session *usess = session->ust_session;
2650
2651 /* Get channel from global UST domain */
2652 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2653 channel_name);
2654 if (uchan == NULL) {
2655 /* Create default channel */
2656 attr = channel_new_default_attr(domain);
2657 if (attr == NULL) {
2658 ret = LTTCOMM_FATAL;
2659 goto error;
2660 }
2661 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2662 attr->name[NAME_MAX - 1] = '\0';
2663
2664 /* Use the internal command enable channel */
2665 ret = channel_ust_create(usess, domain, attr);
2666 if (ret != LTTCOMM_OK) {
2667 free(attr);
2668 goto error;
2669 }
2670 free(attr);
2671
2672 /* Get the newly created channel reference back */
2673 uchan = trace_ust_find_channel_by_name(
2674 usess->domain_global.channels, channel_name);
2675 if (uchan == NULL) {
2676 /* Something is really wrong */
2677 ret = LTTCOMM_FATAL;
2678 goto error;
2679 }
2680 }
2681
2682 /* At this point, the session and channel exist on the tracer */
2683
2684 switch (event_type) {
2685 case LTTNG_EVENT_ALL:
2686 case LTTNG_EVENT_TRACEPOINT:
2687 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
2688 if (ret != LTTCOMM_OK) {
2689 goto error;
2690 }
2691 break;
2692 default:
2693 ret = LTTCOMM_UST_ENABLE_FAIL;
2694 goto error;
2695 }
2696
2697 /* Manage return value */
2698 if (ret != LTTCOMM_OK) {
2699 goto error;
2700 }
2701
2702 break;
2703 }
2704 #if 0
2705 case LTTNG_DOMAIN_UST_EXEC_NAME:
2706 case LTTNG_DOMAIN_UST_PID:
2707 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2708 #endif
2709 default:
2710 ret = LTTCOMM_UND;
2711 goto error;
2712 }
2713
2714 ret = LTTCOMM_OK;
2715
2716 error:
2717 return ret;
2718 }
2719
2720 /*
2721 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2722 */
2723 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2724 {
2725 int ret;
2726 ssize_t nb_events = 0;
2727
2728 switch (domain) {
2729 case LTTNG_DOMAIN_KERNEL:
2730 nb_events = kernel_list_events(kernel_tracer_fd, events);
2731 if (nb_events < 0) {
2732 ret = LTTCOMM_KERN_LIST_FAIL;
2733 goto error;
2734 }
2735 break;
2736 case LTTNG_DOMAIN_UST:
2737 nb_events = ust_app_list_events(events);
2738 if (nb_events < 0) {
2739 ret = LTTCOMM_UST_LIST_FAIL;
2740 goto error;
2741 }
2742 break;
2743 default:
2744 ret = LTTCOMM_UND;
2745 goto error;
2746 }
2747
2748 return nb_events;
2749
2750 error:
2751 /* Return negative value to differentiate return code */
2752 return -ret;
2753 }
2754
2755 /*
2756 * Command LTTNG_START_TRACE processed by the client thread.
2757 */
2758 static int cmd_start_trace(struct ltt_session *session)
2759 {
2760 int ret;
2761 struct ltt_kernel_session *ksession;
2762 struct ltt_ust_session *usess;
2763
2764 /* Short cut */
2765 ksession = session->kernel_session;
2766 usess = session->ust_session;
2767
2768 if (session->enabled) {
2769 ret = LTTCOMM_UST_START_FAIL;
2770 goto error;
2771 }
2772
2773 session->enabled = 1;
2774
2775 /* Kernel tracing */
2776 if (ksession != NULL) {
2777 struct ltt_kernel_channel *kchan;
2778
2779 /* Open kernel metadata */
2780 if (ksession->metadata == NULL) {
2781 ret = kernel_open_metadata(ksession, ksession->trace_path);
2782 if (ret < 0) {
2783 ret = LTTCOMM_KERN_META_FAIL;
2784 goto error;
2785 }
2786 }
2787
2788 /* Open kernel metadata stream */
2789 if (ksession->metadata_stream_fd == 0) {
2790 ret = kernel_open_metadata_stream(ksession);
2791 if (ret < 0) {
2792 ERR("Kernel create metadata stream failed");
2793 ret = LTTCOMM_KERN_STREAM_FAIL;
2794 goto error;
2795 }
2796 }
2797
2798 /* For each channel */
2799 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2800 if (kchan->stream_count == 0) {
2801 ret = kernel_open_channel_stream(kchan);
2802 if (ret < 0) {
2803 ret = LTTCOMM_KERN_STREAM_FAIL;
2804 goto error;
2805 }
2806 /* Update the stream global counter */
2807 ksession->stream_count_global += ret;
2808 }
2809 }
2810
2811 /* Setup kernel consumer socket and send fds to it */
2812 ret = init_kernel_tracing(ksession);
2813 if (ret < 0) {
2814 ret = LTTCOMM_KERN_START_FAIL;
2815 goto error;
2816 }
2817
2818 /* This start the kernel tracing */
2819 ret = kernel_start_session(ksession);
2820 if (ret < 0) {
2821 ret = LTTCOMM_KERN_START_FAIL;
2822 goto error;
2823 }
2824
2825 /* Quiescent wait after starting trace */
2826 kernel_wait_quiescent(kernel_tracer_fd);
2827 }
2828
2829 /* Flag session that trace should start automatically */
2830 if (usess) {
2831 usess->start_trace = 1;
2832
2833 ret = ust_app_start_trace_all(usess);
2834 if (ret < 0) {
2835 ret = LTTCOMM_UST_START_FAIL;
2836 goto error;
2837 }
2838 }
2839
2840 ret = LTTCOMM_OK;
2841
2842 error:
2843 return ret;
2844 }
2845
2846 /*
2847 * Command LTTNG_STOP_TRACE processed by the client thread.
2848 */
2849 static int cmd_stop_trace(struct ltt_session *session)
2850 {
2851 int ret;
2852 struct ltt_kernel_channel *kchan;
2853 struct ltt_kernel_session *ksession;
2854 struct ltt_ust_session *usess;
2855
2856 /* Short cut */
2857 ksession = session->kernel_session;
2858 usess = session->ust_session;
2859
2860 if (!session->enabled) {
2861 ret = LTTCOMM_UST_STOP_FAIL;
2862 goto error;
2863 }
2864
2865 session->enabled = 0;
2866
2867 /* Kernel tracer */
2868 if (ksession != NULL) {
2869 DBG("Stop kernel tracing");
2870
2871 /* Flush all buffers before stopping */
2872 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2873 if (ret < 0) {
2874 ERR("Kernel metadata flush failed");
2875 }
2876
2877 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2878 ret = kernel_flush_buffer(kchan);
2879 if (ret < 0) {
2880 ERR("Kernel flush buffer error");
2881 }
2882 }
2883
2884 ret = kernel_stop_session(ksession);
2885 if (ret < 0) {
2886 ret = LTTCOMM_KERN_STOP_FAIL;
2887 goto error;
2888 }
2889
2890 kernel_wait_quiescent(kernel_tracer_fd);
2891 }
2892
2893 if (usess) {
2894 usess->start_trace = 0;
2895
2896 ret = ust_app_stop_trace_all(usess);
2897 if (ret < 0) {
2898 ret = LTTCOMM_UST_STOP_FAIL;
2899 goto error;
2900 }
2901 }
2902
2903 ret = LTTCOMM_OK;
2904
2905 error:
2906 return ret;
2907 }
2908
2909 /*
2910 * Command LTTNG_CREATE_SESSION processed by the client thread.
2911 */
2912 static int cmd_create_session(char *name, char *path, struct ucred *creds)
2913 {
2914 int ret;
2915
2916 ret = session_create(name, path, creds->uid, creds->gid);
2917 if (ret != LTTCOMM_OK) {
2918 goto error;
2919 }
2920
2921 ret = LTTCOMM_OK;
2922
2923 error:
2924 return ret;
2925 }
2926
2927 /*
2928 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2929 */
2930 static int cmd_destroy_session(struct ltt_session *session, char *name)
2931 {
2932 int ret;
2933
2934 /* Clean kernel session teardown */
2935 teardown_kernel_session(session);
2936 /* UST session teardown */
2937 teardown_ust_session(session);
2938
2939 /*
2940 * Must notify the kernel thread here to update it's poll setin order
2941 * to remove the channel(s)' fd just destroyed.
2942 */
2943 ret = notify_thread_pipe(kernel_poll_pipe[1]);
2944 if (ret < 0) {
2945 perror("write kernel poll pipe");
2946 }
2947
2948 ret = session_destroy(session);
2949
2950 return ret;
2951 }
2952
2953 /*
2954 * Command LTTNG_CALIBRATE processed by the client thread.
2955 */
2956 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2957 {
2958 int ret;
2959
2960 switch (domain) {
2961 case LTTNG_DOMAIN_KERNEL:
2962 {
2963 struct lttng_kernel_calibrate kcalibrate;
2964
2965 kcalibrate.type = calibrate->type;
2966 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2967 if (ret < 0) {
2968 ret = LTTCOMM_KERN_ENABLE_FAIL;
2969 goto error;
2970 }
2971 break;
2972 }
2973 case LTTNG_DOMAIN_UST:
2974 {
2975 struct lttng_ust_calibrate ucalibrate;
2976
2977 ucalibrate.type = calibrate->type;
2978 ret = ust_app_calibrate_glb(&ucalibrate);
2979 if (ret < 0) {
2980 ret = LTTCOMM_UST_CALIBRATE_FAIL;
2981 goto error;
2982 }
2983 break;
2984 }
2985 default:
2986 ret = LTTCOMM_UND;
2987 goto error;
2988 }
2989
2990 ret = LTTCOMM_OK;
2991
2992 error:
2993 return ret;
2994 }
2995
2996 /*
2997 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
2998 */
2999 static int cmd_register_consumer(struct ltt_session *session, int domain,
3000 char *sock_path)
3001 {
3002 int ret, sock;
3003
3004 switch (domain) {
3005 case LTTNG_DOMAIN_KERNEL:
3006 /* Can't register a consumer if there is already one */
3007 if (session->kernel_session->consumer_fds_sent != 0) {
3008 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3009 goto error;
3010 }
3011
3012 sock = lttcomm_connect_unix_sock(sock_path);
3013 if (sock < 0) {
3014 ret = LTTCOMM_CONNECT_FAIL;
3015 goto error;
3016 }
3017
3018 session->kernel_session->consumer_fd = sock;
3019 break;
3020 default:
3021 /* TODO: Userspace tracing */
3022 ret = LTTCOMM_UND;
3023 goto error;
3024 }
3025
3026 ret = LTTCOMM_OK;
3027
3028 error:
3029 return ret;
3030 }
3031
3032 /*
3033 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3034 */
3035 static ssize_t cmd_list_domains(struct ltt_session *session,
3036 struct lttng_domain **domains)
3037 {
3038 int ret, index = 0;
3039 ssize_t nb_dom = 0;
3040
3041 if (session->kernel_session != NULL) {
3042 DBG3("Listing domains found kernel domain");
3043 nb_dom++;
3044 }
3045
3046 if (session->ust_session != NULL) {
3047 DBG3("Listing domains found UST global domain");
3048 nb_dom++;
3049 }
3050
3051 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3052 if (*domains == NULL) {
3053 ret = -LTTCOMM_FATAL;
3054 goto error;
3055 }
3056
3057 if (session->kernel_session != NULL) {
3058 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3059 index++;
3060 }
3061
3062 if (session->ust_session != NULL) {
3063 (*domains)[index].type = LTTNG_DOMAIN_UST;
3064 index++;
3065 }
3066
3067 return nb_dom;
3068
3069 error:
3070 return ret;
3071 }
3072
3073 /*
3074 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3075 */
3076 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
3077 struct lttng_channel **channels)
3078 {
3079 int ret;
3080 ssize_t nb_chan = 0;
3081
3082 switch (domain) {
3083 case LTTNG_DOMAIN_KERNEL:
3084 if (session->kernel_session != NULL) {
3085 nb_chan = session->kernel_session->channel_count;
3086 }
3087 DBG3("Number of kernel channels %zd", nb_chan);
3088 break;
3089 case LTTNG_DOMAIN_UST:
3090 if (session->ust_session != NULL) {
3091 nb_chan = lttng_ht_get_count(
3092 session->ust_session->domain_global.channels);
3093 }
3094 DBG3("Number of UST global channels %zd", nb_chan);
3095 break;
3096 default:
3097 *channels = NULL;
3098 ret = -LTTCOMM_UND;
3099 goto error;
3100 }
3101
3102 if (nb_chan > 0) {
3103 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
3104 if (*channels == NULL) {
3105 ret = -LTTCOMM_FATAL;
3106 goto error;
3107 }
3108
3109 list_lttng_channels(domain, session, *channels);
3110 } else {
3111 *channels = NULL;
3112 }
3113
3114 return nb_chan;
3115
3116 error:
3117 return ret;
3118 }
3119
3120 /*
3121 * Command LTTNG_LIST_EVENTS processed by the client thread.
3122 */
3123 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
3124 char *channel_name, struct lttng_event **events)
3125 {
3126 int ret = 0;
3127 ssize_t nb_event = 0;
3128
3129 switch (domain) {
3130 case LTTNG_DOMAIN_KERNEL:
3131 if (session->kernel_session != NULL) {
3132 nb_event = list_lttng_kernel_events(channel_name,
3133 session->kernel_session, events);
3134 }
3135 break;
3136 case LTTNG_DOMAIN_UST:
3137 {
3138 if (session->ust_session != NULL) {
3139 nb_event = list_lttng_ust_global_events(channel_name,
3140 &session->ust_session->domain_global, events);
3141 }
3142 break;
3143 }
3144 default:
3145 ret = -LTTCOMM_UND;
3146 goto error;
3147 }
3148
3149 ret = nb_event;
3150
3151 error:
3152 return ret;
3153 }
3154
3155 /*
3156 * Process the command requested by the lttng client within the command
3157 * context structure. This function make sure that the return structure (llm)
3158 * is set and ready for transmission before returning.
3159 *
3160 * Return any error encountered or 0 for success.
3161 */
3162 static int process_client_msg(struct command_ctx *cmd_ctx)
3163 {
3164 int ret = LTTCOMM_OK;
3165 int need_tracing_session = 1;
3166 int need_domain;
3167
3168 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
3169
3170 switch (cmd_ctx->lsm->cmd_type) {
3171 case LTTNG_CREATE_SESSION:
3172 case LTTNG_DESTROY_SESSION:
3173 case LTTNG_LIST_SESSIONS:
3174 case LTTNG_LIST_DOMAINS:
3175 case LTTNG_START_TRACE:
3176 case LTTNG_STOP_TRACE:
3177 need_domain = 0;
3178 break;
3179 default:
3180 need_domain = 1;
3181 }
3182
3183 if (opt_no_kernel && need_domain
3184 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
3185 ret = LTTCOMM_KERN_NA;
3186 goto error;
3187 }
3188
3189 /*
3190 * Check for command that don't needs to allocate a returned payload. We do
3191 * this here so we don't have to make the call for no payload at each
3192 * command.
3193 */
3194 switch(cmd_ctx->lsm->cmd_type) {
3195 case LTTNG_LIST_SESSIONS:
3196 case LTTNG_LIST_TRACEPOINTS:
3197 case LTTNG_LIST_DOMAINS:
3198 case LTTNG_LIST_CHANNELS:
3199 case LTTNG_LIST_EVENTS:
3200 break;
3201 default:
3202 /* Setup lttng message with no payload */
3203 ret = setup_lttng_msg(cmd_ctx, 0);
3204 if (ret < 0) {
3205 /* This label does not try to unlock the session */
3206 goto init_setup_error;
3207 }
3208 }
3209
3210 /* Commands that DO NOT need a session. */
3211 switch (cmd_ctx->lsm->cmd_type) {
3212 case LTTNG_CREATE_SESSION:
3213 case LTTNG_CALIBRATE:
3214 case LTTNG_LIST_SESSIONS:
3215 case LTTNG_LIST_TRACEPOINTS:
3216 need_tracing_session = 0;
3217 break;
3218 default:
3219 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
3220 session_lock_list();
3221 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
3222 session_unlock_list();
3223 if (cmd_ctx->session == NULL) {
3224 if (cmd_ctx->lsm->session.name != NULL) {
3225 ret = LTTCOMM_SESS_NOT_FOUND;
3226 } else {
3227 /* If no session name specified */
3228 ret = LTTCOMM_SELECT_SESS;
3229 }
3230 goto error;
3231 } else {
3232 /* Acquire lock for the session */
3233 session_lock(cmd_ctx->session);
3234 }
3235 break;
3236 }
3237
3238 if (!need_domain) {
3239 goto skip_domain;
3240 }
3241 /*
3242 * Check domain type for specific "pre-action".
3243 */
3244 switch (cmd_ctx->lsm->domain.type) {
3245 case LTTNG_DOMAIN_KERNEL:
3246 if (!is_root) {
3247 ret = LTTCOMM_KERN_NA;
3248 goto error;
3249 }
3250
3251 /* Kernel tracer check */
3252 if (kernel_tracer_fd == 0) {
3253 /* Basically, load kernel tracer modules */
3254 ret = init_kernel_tracer();
3255 if (ret != 0) {
3256 goto error;
3257 }
3258 }
3259
3260 /* Need a session for kernel command */
3261 if (need_tracing_session) {
3262 if (cmd_ctx->session->kernel_session == NULL) {
3263 ret = create_kernel_session(cmd_ctx->session);
3264 if (ret < 0) {
3265 ret = LTTCOMM_KERN_SESS_FAIL;
3266 goto error;
3267 }
3268 }
3269
3270 /* Start the kernel consumer daemon */