Merge branch 'master' into compat-freebsd
[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 <getopt.h>
21 #include <grp.h>
22 #include <limits.h>
23 #include <pthread.h>
24 #include <semaphore.h>
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sys/mman.h>
30 #include <sys/mount.h>
31 #include <sys/resource.h>
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 #include <urcu/futex.h>
37 #include <unistd.h>
38 #include <config.h>
39
40 #include <common/common.h>
41 #include <common/compat/poll.h>
42 #include <common/compat/socket.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, i;
299
300 ret = pipe(thread_quit_pipe);
301 if (ret < 0) {
302 PERROR("thread quit pipe");
303 goto error;
304 }
305
306 for (i = 0; i < 2; i++) {
307 ret = fcntl(thread_quit_pipe[i], F_SETFD, FD_CLOEXEC);
308 if (ret < 0) {
309 PERROR("fcntl");
310 goto error;
311 }
312 }
313
314 error:
315 return ret;
316 }
317
318 /*
319 * Complete teardown of a kernel session. This free all data structure related
320 * to a kernel session and update counter.
321 */
322 static void teardown_kernel_session(struct ltt_session *session)
323 {
324 if (!session->kernel_session) {
325 DBG3("No kernel session when tearing down session");
326 return;
327 }
328
329 DBG("Tearing down kernel session");
330
331 /*
332 * If a custom kernel consumer was registered, close the socket before
333 * tearing down the complete kernel session structure
334 */
335 if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
336 lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
337 }
338
339 trace_kernel_destroy_session(session->kernel_session);
340 }
341
342 /*
343 * Complete teardown of all UST sessions. This will free everything on his path
344 * and destroy the core essence of all ust sessions :)
345 */
346 static void teardown_ust_session(struct ltt_session *session)
347 {
348 int ret;
349
350 if (!session->ust_session) {
351 DBG3("No UST session when tearing down session");
352 return;
353 }
354
355 DBG("Tearing down UST session(s)");
356
357 ret = ust_app_destroy_trace_all(session->ust_session);
358 if (ret) {
359 ERR("Error in ust_app_destroy_trace_all");
360 }
361
362 trace_ust_destroy_session(session->ust_session);
363 }
364
365 /*
366 * Stop all threads by closing the thread quit pipe.
367 */
368 static void stop_threads(void)
369 {
370 int ret;
371
372 /* Stopping all threads */
373 DBG("Terminating all threads");
374 ret = notify_thread_pipe(thread_quit_pipe[1]);
375 if (ret < 0) {
376 ERR("write error on thread quit pipe");
377 }
378
379 /* Dispatch thread */
380 dispatch_thread_exit = 1;
381 futex_nto1_wake(&ust_cmd_queue.futex);
382 }
383
384 /*
385 * Cleanup the daemon
386 */
387 static void cleanup(void)
388 {
389 int ret;
390 char *cmd;
391 struct ltt_session *sess, *stmp;
392
393 DBG("Cleaning up");
394
395 DBG("Removing %s directory", rundir);
396 ret = asprintf(&cmd, "rm -rf %s", rundir);
397 if (ret < 0) {
398 ERR("asprintf failed. Something is really wrong!");
399 }
400
401 /* Remove lttng run directory */
402 ret = system(cmd);
403 if (ret < 0) {
404 ERR("Unable to clean %s", rundir);
405 }
406 free(cmd);
407
408 DBG("Cleaning up all sessions");
409
410 /* Destroy session list mutex */
411 if (session_list_ptr != NULL) {
412 pthread_mutex_destroy(&session_list_ptr->lock);
413
414 /* Cleanup ALL session */
415 cds_list_for_each_entry_safe(sess, stmp,
416 &session_list_ptr->head, list) {
417 teardown_kernel_session(sess);
418 teardown_ust_session(sess);
419 free(sess);
420 }
421 }
422
423 DBG("Closing all UST sockets");
424 ust_app_clean_list();
425
426 pthread_mutex_destroy(&kconsumer_data.pid_mutex);
427
428 if (is_root && !opt_no_kernel) {
429 DBG2("Closing kernel fd");
430 close(kernel_tracer_fd);
431 DBG("Unloading kernel modules");
432 modprobe_remove_lttng_all();
433 }
434
435 close(thread_quit_pipe[0]);
436 close(thread_quit_pipe[1]);
437
438 /* <fun> */
439 DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
440 "Matthew, BEET driven development works!%c[%dm",
441 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
442 /* </fun> */
443 }
444
445 /*
446 * Send data on a unix socket using the liblttsessiondcomm API.
447 *
448 * Return lttcomm error code.
449 */
450 static int send_unix_sock(int sock, void *buf, size_t len)
451 {
452 /* Check valid length */
453 if (len <= 0) {
454 return -1;
455 }
456
457 return lttcomm_send_unix_sock(sock, buf, len);
458 }
459
460 /*
461 * Free memory of a command context structure.
462 */
463 static void clean_command_ctx(struct command_ctx **cmd_ctx)
464 {
465 DBG("Clean command context structure");
466 if (*cmd_ctx) {
467 if ((*cmd_ctx)->llm) {
468 free((*cmd_ctx)->llm);
469 }
470 if ((*cmd_ctx)->lsm) {
471 free((*cmd_ctx)->lsm);
472 }
473 free(*cmd_ctx);
474 *cmd_ctx = NULL;
475 }
476 }
477
478 /*
479 * Send all stream fds of kernel channel to the consumer.
480 */
481 static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
482 int sock, struct ltt_kernel_channel *channel,
483 uid_t uid, gid_t gid)
484 {
485 int ret;
486 struct ltt_kernel_stream *stream;
487 struct lttcomm_consumer_msg lkm;
488
489 DBG("Sending streams of channel %s to kernel consumer",
490 channel->channel->name);
491
492 /* Send channel */
493 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
494 lkm.u.channel.channel_key = channel->fd;
495 lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
496 lkm.u.channel.mmap_len = 0; /* for kernel */
497 DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
498 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
499 if (ret < 0) {
500 perror("send consumer channel");
501 goto error;
502 }
503
504 /* Send streams */
505 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
506 if (!stream->fd) {
507 continue;
508 }
509 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
510 lkm.u.stream.channel_key = channel->fd;
511 lkm.u.stream.stream_key = stream->fd;
512 lkm.u.stream.state = stream->state;
513 lkm.u.stream.output = channel->channel->attr.output;
514 lkm.u.stream.mmap_len = 0; /* for kernel */
515 lkm.u.stream.uid = uid;
516 lkm.u.stream.gid = gid;
517 strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
518 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
519 DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
520 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
521 if (ret < 0) {
522 perror("send consumer stream");
523 goto error;
524 }
525 ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
526 if (ret < 0) {
527 perror("send consumer stream ancillary data");
528 goto error;
529 }
530 }
531
532 DBG("consumer channel streams sent");
533
534 return 0;
535
536 error:
537 return ret;
538 }
539
540 /*
541 * Send all stream fds of the kernel session to the consumer.
542 */
543 static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
544 struct ltt_kernel_session *session)
545 {
546 int ret;
547 struct ltt_kernel_channel *chan;
548 struct lttcomm_consumer_msg lkm;
549 int sock = session->consumer_fd;
550
551 DBG("Sending metadata stream fd");
552
553 /* Extra protection. It's NOT supposed to be set to 0 at this point */
554 if (session->consumer_fd == 0) {
555 session->consumer_fd = consumer_data->cmd_sock;
556 }
557
558 if (session->metadata_stream_fd != 0) {
559 /* Send metadata channel fd */
560 lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
561 lkm.u.channel.channel_key = session->metadata->fd;
562 lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
563 lkm.u.channel.mmap_len = 0; /* for kernel */
564 DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
565 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
566 if (ret < 0) {
567 perror("send consumer channel");
568 goto error;
569 }
570
571 /* Send metadata stream fd */
572 lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
573 lkm.u.stream.channel_key = session->metadata->fd;
574 lkm.u.stream.stream_key = session->metadata_stream_fd;
575 lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
576 lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
577 lkm.u.stream.mmap_len = 0; /* for kernel */
578 lkm.u.stream.uid = session->uid;
579 lkm.u.stream.gid = session->gid;
580 strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
581 lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
582 DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
583 ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
584 if (ret < 0) {
585 perror("send consumer stream");
586 goto error;
587 }
588 ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
589 if (ret < 0) {
590 perror("send consumer stream");
591 goto error;
592 }
593 }
594
595 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
596 ret = send_kconsumer_channel_streams(consumer_data, sock, chan,
597 session->uid, session->gid);
598 if (ret < 0) {
599 goto error;
600 }
601 }
602
603 DBG("consumer fds (metadata and channel streams) sent");
604
605 return 0;
606
607 error:
608 return ret;
609 }
610
611 /*
612 * Notify UST applications using the shm mmap futex.
613 */
614 static int notify_ust_apps(int active)
615 {
616 char *wait_shm_mmap;
617
618 DBG("Notifying applications of session daemon state: %d", active);
619
620 /* See shm.c for this call implying mmap, shm and futex calls */
621 wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
622 if (wait_shm_mmap == NULL) {
623 goto error;
624 }
625
626 /* Wake waiting process */
627 futex_wait_update((int32_t *) wait_shm_mmap, active);
628
629 /* Apps notified successfully */
630 return 0;
631
632 error:
633 return -1;
634 }
635
636 /*
637 * Setup the outgoing data buffer for the response (llm) by allocating the
638 * right amount of memory and copying the original information from the lsm
639 * structure.
640 *
641 * Return total size of the buffer pointed by buf.
642 */
643 static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
644 {
645 int ret, buf_size;
646
647 buf_size = size;
648
649 cmd_ctx->llm = zmalloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
650 if (cmd_ctx->llm == NULL) {
651 perror("zmalloc");
652 ret = -ENOMEM;
653 goto error;
654 }
655
656 /* Copy common data */
657 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
658 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
659
660 cmd_ctx->llm->data_size = size;
661 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
662
663 return buf_size;
664
665 error:
666 return ret;
667 }
668
669 /*
670 * Update the kernel poll set of all channel fd available over all tracing
671 * session. Add the wakeup pipe at the end of the set.
672 */
673 static int update_kernel_poll(struct lttng_poll_event *events)
674 {
675 int ret;
676 struct ltt_session *session;
677 struct ltt_kernel_channel *channel;
678
679 DBG("Updating kernel poll set");
680
681 session_lock_list();
682 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
683 session_lock(session);
684 if (session->kernel_session == NULL) {
685 session_unlock(session);
686 continue;
687 }
688
689 cds_list_for_each_entry(channel,
690 &session->kernel_session->channel_list.head, list) {
691 /* Add channel fd to the kernel poll set */
692 ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
693 if (ret < 0) {
694 session_unlock(session);
695 goto error;
696 }
697 DBG("Channel fd %d added to kernel set", channel->fd);
698 }
699 session_unlock(session);
700 }
701 session_unlock_list();
702
703 return 0;
704
705 error:
706 session_unlock_list();
707 return -1;
708 }
709
710 /*
711 * Find the channel fd from 'fd' over all tracing session. When found, check
712 * for new channel stream and send those stream fds to the kernel consumer.
713 *
714 * Useful for CPU hotplug feature.
715 */
716 static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
717 {
718 int ret = 0;
719 struct ltt_session *session;
720 struct ltt_kernel_channel *channel;
721
722 DBG("Updating kernel streams for channel fd %d", fd);
723
724 session_lock_list();
725 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
726 session_lock(session);
727 if (session->kernel_session == NULL) {
728 session_unlock(session);
729 continue;
730 }
731
732 /* This is not suppose to be 0 but this is an extra security check */
733 if (session->kernel_session->consumer_fd == 0) {
734 session->kernel_session->consumer_fd = consumer_data->cmd_sock;
735 }
736
737 cds_list_for_each_entry(channel,
738 &session->kernel_session->channel_list.head, list) {
739 if (channel->fd == fd) {
740 DBG("Channel found, updating kernel streams");
741 ret = kernel_open_channel_stream(channel);
742 if (ret < 0) {
743 goto error;
744 }
745
746 /*
747 * Have we already sent fds to the consumer? If yes, it means
748 * that tracing is started so it is safe to send our updated
749 * stream fds.
750 */
751 if (session->kernel_session->consumer_fds_sent == 1) {
752 ret = send_kconsumer_channel_streams(consumer_data,
753 session->kernel_session->consumer_fd, channel,
754 session->uid, session->gid);
755 if (ret < 0) {
756 goto error;
757 }
758 }
759 goto error;
760 }
761 }
762 session_unlock(session);
763 }
764 session_unlock_list();
765 return ret;
766
767 error:
768 session_unlock(session);
769 session_unlock_list();
770 return ret;
771 }
772
773 /*
774 * For each tracing session, update newly registered apps.
775 */
776 static void update_ust_app(int app_sock)
777 {
778 struct ltt_session *sess, *stmp;
779
780 session_lock_list();
781
782 /* For all tracing session(s) */
783 cds_list_for_each_entry_safe(sess, stmp, &session_list_ptr->head, list) {
784 session_lock(sess);
785 if (sess->ust_session) {
786 ust_app_global_update(sess->ust_session, app_sock);
787 }
788 session_unlock(sess);
789 }
790
791 session_unlock_list();
792 }
793
794 /*
795 * This thread manage event coming from the kernel.
796 *
797 * Features supported in this thread:
798 * -) CPU Hotplug
799 */
800 static void *thread_manage_kernel(void *data)
801 {
802 int ret, i, pollfd, update_poll_flag = 1;
803 uint32_t revents, nb_fd;
804 char tmp;
805 struct lttng_poll_event events;
806
807 DBG("Thread manage kernel started");
808
809 ret = create_thread_poll_set(&events, 2);
810 if (ret < 0) {
811 goto error;
812 }
813
814 ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
815 if (ret < 0) {
816 goto error;
817 }
818
819 while (1) {
820 if (update_poll_flag == 1) {
821 /*
822 * Reset number of fd in the poll set. Always 2 since there is the thread
823 * quit pipe and the kernel pipe.
824 */
825 events.nb_fd = 2;
826
827 ret = update_kernel_poll(&events);
828 if (ret < 0) {
829 goto error;
830 }
831 update_poll_flag = 0;
832 }
833
834 nb_fd = LTTNG_POLL_GETNB(&events);
835
836 DBG("Thread kernel polling on %d fds", nb_fd);
837
838 /* Zeroed the poll events */
839 lttng_poll_reset(&events);
840
841 /* Poll infinite value of time */
842 restart:
843 ret = lttng_poll_wait(&events, -1);
844 if (ret < 0) {
845 /*
846 * Restart interrupted system call.
847 */
848 if (errno == EINTR) {
849 goto restart;
850 }
851 goto error;
852 } else if (ret == 0) {
853 /* Should not happen since timeout is infinite */
854 ERR("Return value of poll is 0 with an infinite timeout.\n"
855 "This should not have happened! Continuing...");
856 continue;
857 }
858
859 for (i = 0; i < nb_fd; i++) {
860 /* Fetch once the poll data */
861 revents = LTTNG_POLL_GETEV(&events, i);
862 pollfd = LTTNG_POLL_GETFD(&events, i);
863
864 /* Thread quit pipe has been closed. Killing thread. */
865 ret = check_thread_quit_pipe(pollfd, revents);
866 if (ret) {
867 goto error;
868 }
869
870 /* Check for data on kernel pipe */
871 if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
872 ret = read(kernel_poll_pipe[0], &tmp, 1);
873 update_poll_flag = 1;
874 continue;
875 } else {
876 /*
877 * New CPU detected by the kernel. Adding kernel stream to
878 * kernel session and updating the kernel consumer
879 */
880 if (revents & LPOLLIN) {
881 ret = update_kernel_stream(&kconsumer_data, pollfd);
882 if (ret < 0) {
883 continue;
884 }
885 break;
886 /*
887 * TODO: We might want to handle the LPOLLERR | LPOLLHUP
888 * and unregister kernel stream at this point.
889 */
890 }
891 }
892 }
893 }
894
895 error:
896 DBG("Kernel thread dying");
897 close(kernel_poll_pipe[0]);
898 close(kernel_poll_pipe[1]);
899
900 lttng_poll_clean(&events);
901
902 return NULL;
903 }
904
905 /*
906 * This thread manage the consumer error sent back to the session daemon.
907 */
908 static void *thread_manage_consumer(void *data)
909 {
910 int sock = 0, i, ret, pollfd;
911 uint32_t revents, nb_fd;
912 enum lttcomm_return_code code;
913 struct lttng_poll_event events;
914 struct consumer_data *consumer_data = data;
915
916 DBG("[thread] Manage consumer started");
917
918 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
919 if (ret < 0) {
920 goto error;
921 }
922
923 /*
924 * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
925 * Nothing more will be added to this poll set.
926 */
927 ret = create_thread_poll_set(&events, 2);
928 if (ret < 0) {
929 goto error;
930 }
931
932 ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
933 if (ret < 0) {
934 goto error;
935 }
936
937 nb_fd = LTTNG_POLL_GETNB(&events);
938
939 /* Inifinite blocking call, waiting for transmission */
940 restart:
941 ret = lttng_poll_wait(&events, -1);
942 if (ret < 0) {
943 /*
944 * Restart interrupted system call.
945 */
946 if (errno == EINTR) {
947 goto restart;
948 }
949 goto error;
950 }
951
952 for (i = 0; i < nb_fd; i++) {
953 /* Fetch once the poll data */
954 revents = LTTNG_POLL_GETEV(&events, i);
955 pollfd = LTTNG_POLL_GETFD(&events, i);
956
957 /* Thread quit pipe has been closed. Killing thread. */
958 ret = check_thread_quit_pipe(pollfd, revents);
959 if (ret) {
960 goto error;
961 }
962
963 /* Event on the registration socket */
964 if (pollfd == consumer_data->err_sock) {
965 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
966 ERR("consumer err socket poll error");
967 goto error;
968 }
969 }
970 }
971
972 sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
973 if (sock < 0) {
974 goto error;
975 }
976
977 DBG2("Receiving code from consumer err_sock");
978
979 /* Getting status code from kconsumerd */
980 ret = lttcomm_recv_unix_sock(sock, &code,
981 sizeof(enum lttcomm_return_code));
982 if (ret <= 0) {
983 goto error;
984 }
985
986 if (code == CONSUMERD_COMMAND_SOCK_READY) {
987 consumer_data->cmd_sock =
988 lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
989 if (consumer_data->cmd_sock < 0) {
990 sem_post(&consumer_data->sem);
991 PERROR("consumer connect");
992 goto error;
993 }
994 /* Signal condition to tell that the kconsumerd is ready */
995 sem_post(&consumer_data->sem);
996 DBG("consumer command socket ready");
997 } else {
998 ERR("consumer error when waiting for SOCK_READY : %s",
999 lttcomm_get_readable_code(-code));
1000 goto error;
1001 }
1002
1003 /* Remove the kconsumerd error sock since we've established a connexion */
1004 ret = lttng_poll_del(&events, consumer_data->err_sock);
1005 if (ret < 0) {
1006 goto error;
1007 }
1008
1009 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
1010 if (ret < 0) {
1011 goto error;
1012 }
1013
1014 /* Update number of fd */
1015 nb_fd = LTTNG_POLL_GETNB(&events);
1016
1017 /* Inifinite blocking call, waiting for transmission */
1018 restart_poll:
1019 ret = lttng_poll_wait(&events, -1);
1020 if (ret < 0) {
1021 /*
1022 * Restart interrupted system call.
1023 */
1024 if (errno == EINTR) {
1025 goto restart_poll;
1026 }
1027 goto error;
1028 }
1029
1030 for (i = 0; i < nb_fd; i++) {
1031 /* Fetch once the poll data */
1032 revents = LTTNG_POLL_GETEV(&events, i);
1033 pollfd = LTTNG_POLL_GETFD(&events, i);
1034
1035 /* Thread quit pipe has been closed. Killing thread. */
1036 ret = check_thread_quit_pipe(pollfd, revents);
1037 if (ret) {
1038 goto error;
1039 }
1040
1041 /* Event on the kconsumerd socket */
1042 if (pollfd == sock) {
1043 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1044 ERR("consumer err socket second poll error");
1045 goto error;
1046 }
1047 }
1048 }
1049
1050 /* Wait for any kconsumerd error */
1051 ret = lttcomm_recv_unix_sock(sock, &code,
1052 sizeof(enum lttcomm_return_code));
1053 if (ret <= 0) {
1054 ERR("consumer closed the command socket");
1055 goto error;
1056 }
1057
1058 ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
1059
1060 error:
1061 DBG("consumer thread dying");
1062 close(consumer_data->err_sock);
1063 close(consumer_data->cmd_sock);
1064 close(sock);
1065
1066 unlink(consumer_data->err_unix_sock_path);
1067 unlink(consumer_data->cmd_unix_sock_path);
1068 consumer_data->pid = 0;
1069
1070 lttng_poll_clean(&events);
1071
1072 return NULL;
1073 }
1074
1075 /*
1076 * This thread manage application communication.
1077 */
1078 static void *thread_manage_apps(void *data)
1079 {
1080 int i, ret, pollfd;
1081 uint32_t revents, nb_fd;
1082 struct ust_command ust_cmd;
1083 struct lttng_poll_event events;
1084
1085 DBG("[thread] Manage application started");
1086
1087 rcu_register_thread();
1088 rcu_thread_online();
1089
1090 ret = create_thread_poll_set(&events, 2);
1091 if (ret < 0) {
1092 goto error;
1093 }
1094
1095 ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1096 if (ret < 0) {
1097 goto error;
1098 }
1099
1100 while (1) {
1101 /* Zeroed the events structure */
1102 lttng_poll_reset(&events);
1103
1104 nb_fd = LTTNG_POLL_GETNB(&events);
1105
1106 DBG("Apps thread polling on %d fds", nb_fd);
1107
1108 /* Inifinite blocking call, waiting for transmission */
1109 restart:
1110 ret = lttng_poll_wait(&events, -1);
1111 if (ret < 0) {
1112 /*
1113 * Restart interrupted system call.
1114 */
1115 if (errno == EINTR) {
1116 goto restart;
1117 }
1118 goto error;
1119 }
1120
1121 for (i = 0; i < nb_fd; i++) {
1122 /* Fetch once the poll data */
1123 revents = LTTNG_POLL_GETEV(&events, i);
1124 pollfd = LTTNG_POLL_GETFD(&events, i);
1125
1126 /* Thread quit pipe has been closed. Killing thread. */
1127 ret = check_thread_quit_pipe(pollfd, revents);
1128 if (ret) {
1129 goto error;
1130 }
1131
1132 /* Inspect the apps cmd pipe */
1133 if (pollfd == apps_cmd_pipe[0]) {
1134 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1135 ERR("Apps command pipe error");
1136 goto error;
1137 } else if (revents & LPOLLIN) {
1138 /* Empty pipe */
1139 ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
1140 if (ret < 0 || ret < sizeof(ust_cmd)) {
1141 perror("read apps cmd pipe");
1142 goto error;
1143 }
1144
1145 /* Register applicaton to the session daemon */
1146 ret = ust_app_register(&ust_cmd.reg_msg,
1147 ust_cmd.sock);
1148 if (ret == -ENOMEM) {
1149 goto error;
1150 } else if (ret < 0) {
1151 break;
1152 }
1153
1154 /*
1155 * Validate UST version compatibility.
1156 */
1157 ret = ust_app_validate_version(ust_cmd.sock);
1158 if (ret >= 0) {
1159 /*
1160 * Add channel(s) and event(s) to newly registered apps
1161 * from lttng global UST domain.
1162 */
1163 update_ust_app(ust_cmd.sock);
1164 }
1165
1166 ret = ust_app_register_done(ust_cmd.sock);
1167 if (ret < 0) {
1168 /*
1169 * If the registration is not possible, we simply
1170 * unregister the apps and continue
1171 */
1172 ust_app_unregister(ust_cmd.sock);
1173 } else {
1174 /*
1175 * We just need here to monitor the close of the UST
1176 * socket and poll set monitor those by default.
1177 * Listen on POLLIN (even if we never expect any
1178 * data) to ensure that hangup wakes us.
1179 */
1180 ret = lttng_poll_add(&events, ust_cmd.sock, LPOLLIN);
1181 if (ret < 0) {
1182 goto error;
1183 }
1184
1185 DBG("Apps with sock %d added to poll set",
1186 ust_cmd.sock);
1187 }
1188
1189 break;
1190 }
1191 } else {
1192 /*
1193 * At this point, we know that a registered application made
1194 * the event at poll_wait.
1195 */
1196 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1197 /* Removing from the poll set */
1198 ret = lttng_poll_del(&events, pollfd);
1199 if (ret < 0) {
1200 goto error;
1201 }
1202
1203 /* Socket closed on remote end. */
1204 ust_app_unregister(pollfd);
1205 break;
1206 }
1207 }
1208 }
1209 }
1210
1211 error:
1212 DBG("Application communication apps dying");
1213 close(apps_cmd_pipe[0]);
1214 close(apps_cmd_pipe[1]);
1215
1216 lttng_poll_clean(&events);
1217
1218 rcu_thread_offline();
1219 rcu_unregister_thread();
1220 return NULL;
1221 }
1222
1223 /*
1224 * Dispatch request from the registration threads to the application
1225 * communication thread.
1226 */
1227 static void *thread_dispatch_ust_registration(void *data)
1228 {
1229 int ret;
1230 struct cds_wfq_node *node;
1231 struct ust_command *ust_cmd = NULL;
1232
1233 DBG("[thread] Dispatch UST command started");
1234
1235 while (!dispatch_thread_exit) {
1236 /* Atomically prepare the queue futex */
1237 futex_nto1_prepare(&ust_cmd_queue.futex);
1238
1239 do {
1240 /* Dequeue command for registration */
1241 node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
1242 if (node == NULL) {
1243 DBG("Woken up but nothing in the UST command queue");
1244 /* Continue thread execution */
1245 break;
1246 }
1247
1248 ust_cmd = caa_container_of(node, struct ust_command, node);
1249
1250 DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
1251 " gid:%d sock:%d name:%s (version %d.%d)",
1252 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1253 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1254 ust_cmd->sock, ust_cmd->reg_msg.name,
1255 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1256 /*
1257 * Inform apps thread of the new application registration. This
1258 * call is blocking so we can be assured that the data will be read
1259 * at some point in time or wait to the end of the world :)
1260 */
1261 ret = write(apps_cmd_pipe[1], ust_cmd,
1262 sizeof(struct ust_command));
1263 if (ret < 0) {
1264 perror("write apps cmd pipe");
1265 if (errno == EBADF) {
1266 /*
1267 * We can't inform the application thread to process
1268 * registration. We will exit or else application
1269 * registration will not occur and tracing will never
1270 * start.
1271 */
1272 goto error;
1273 }
1274 }
1275 free(ust_cmd);
1276 } while (node != NULL);
1277
1278 /* Futex wait on queue. Blocking call on futex() */
1279 futex_nto1_wait(&ust_cmd_queue.futex);
1280 }
1281
1282 error:
1283 DBG("Dispatch thread dying");
1284 return NULL;
1285 }
1286
1287 /*
1288 * This thread manage application registration.
1289 */
1290 static void *thread_registration_apps(void *data)
1291 {
1292 int sock = 0, i, ret, pollfd;
1293 uint32_t revents, nb_fd;
1294 struct lttng_poll_event events;
1295 /*
1296 * Get allocated in this thread, enqueued to a global queue, dequeued and
1297 * freed in the manage apps thread.
1298 */
1299 struct ust_command *ust_cmd = NULL;
1300
1301 DBG("[thread] Manage application registration started");
1302
1303 ret = lttcomm_listen_unix_sock(apps_sock);
1304 if (ret < 0) {
1305 goto error;
1306 }
1307
1308 /*
1309 * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
1310 * more will be added to this poll set.
1311 */
1312 ret = create_thread_poll_set(&events, 2);
1313 if (ret < 0) {
1314 goto error;
1315 }
1316
1317 /* Add the application registration socket */
1318 ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
1319 if (ret < 0) {
1320 goto error;
1321 }
1322
1323 /* Notify all applications to register */
1324 ret = notify_ust_apps(1);
1325 if (ret < 0) {
1326 ERR("Failed to notify applications or create the wait shared memory.\n"
1327 "Execution continues but there might be problem for already\n"
1328 "running applications that wishes to register.");
1329 }
1330
1331 while (1) {
1332 DBG("Accepting application registration");
1333
1334 nb_fd = LTTNG_POLL_GETNB(&events);
1335
1336 /* Inifinite blocking call, waiting for transmission */
1337 restart:
1338 ret = lttng_poll_wait(&events, -1);
1339 if (ret < 0) {
1340 /*
1341 * Restart interrupted system call.
1342 */
1343 if (errno == EINTR) {
1344 goto restart;
1345 }
1346 goto error;
1347 }
1348
1349 for (i = 0; i < nb_fd; i++) {
1350 /* Fetch once the poll data */
1351 revents = LTTNG_POLL_GETEV(&events, i);
1352 pollfd = LTTNG_POLL_GETFD(&events, i);
1353
1354 /* Thread quit pipe has been closed. Killing thread. */
1355 ret = check_thread_quit_pipe(pollfd, revents);
1356 if (ret) {
1357 goto error;
1358 }
1359
1360 /* Event on the registration socket */
1361 if (pollfd == apps_sock) {
1362 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1363 ERR("Register apps socket poll error");
1364 goto error;
1365 } else if (revents & LPOLLIN) {
1366 sock = lttcomm_accept_unix_sock(apps_sock);
1367 if (sock < 0) {
1368 goto error;
1369 }
1370
1371 /* Create UST registration command for enqueuing */
1372 ust_cmd = zmalloc(sizeof(struct ust_command));
1373 if (ust_cmd == NULL) {
1374 perror("ust command zmalloc");
1375 goto error;
1376 }
1377
1378 /*
1379 * Using message-based transmissions to ensure we don't
1380 * have to deal with partially received messages.
1381 */
1382 ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
1383 sizeof(struct ust_register_msg));
1384 if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
1385 if (ret < 0) {
1386 perror("lttcomm_recv_unix_sock register apps");
1387 } else {
1388 ERR("Wrong size received on apps register");
1389 }
1390 free(ust_cmd);
1391 close(sock);
1392 continue;
1393 }
1394
1395 ust_cmd->sock = sock;
1396
1397 DBG("UST registration received with pid:%d ppid:%d uid:%d"
1398 " gid:%d sock:%d name:%s (version %d.%d)",
1399 ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
1400 ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
1401 ust_cmd->sock, ust_cmd->reg_msg.name,
1402 ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
1403
1404 /*
1405 * Lock free enqueue the registration request. The red pill
1406 * has been taken! This apps will be part of the *system*.
1407 */
1408 cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
1409
1410 /*
1411 * Wake the registration queue futex. Implicit memory
1412 * barrier with the exchange in cds_wfq_enqueue.
1413 */
1414 futex_nto1_wake(&ust_cmd_queue.futex);
1415 }
1416 }
1417 }
1418 }
1419
1420 error:
1421 DBG("UST Registration thread dying");
1422
1423 /* Notify that the registration thread is gone */
1424 notify_ust_apps(0);
1425
1426 close(apps_sock);
1427 close(sock);
1428 unlink(apps_unix_sock_path);
1429
1430 lttng_poll_clean(&events);
1431
1432 return NULL;
1433 }
1434
1435 /*
1436 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
1437 * exec or it will fails.
1438 */
1439 static int spawn_consumer_thread(struct consumer_data *consumer_data)
1440 {
1441 int ret;
1442 struct timespec timeout;
1443
1444 timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
1445 timeout.tv_nsec = 0;
1446
1447 /* Setup semaphore */
1448 ret = sem_init(&consumer_data->sem, 0, 0);
1449 if (ret < 0) {
1450 PERROR("sem_init consumer semaphore");
1451 goto error;
1452 }
1453
1454 ret = pthread_create(&consumer_data->thread, NULL,
1455 thread_manage_consumer, consumer_data);
1456 if (ret != 0) {
1457 PERROR("pthread_create consumer");
1458 ret = -1;
1459 goto error;
1460 }
1461
1462 /* Get time for sem_timedwait absolute timeout */
1463 ret = clock_gettime(CLOCK_REALTIME, &timeout);
1464 if (ret < 0) {
1465 PERROR("clock_gettime spawn consumer");
1466 /* Infinite wait for the kconsumerd thread to be ready */
1467 ret = sem_wait(&consumer_data->sem);
1468 } else {
1469 /* Normal timeout if the gettime was successful */
1470 timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
1471 ret = sem_timedwait(&consumer_data->sem, &timeout);
1472 }
1473
1474 if (ret < 0) {
1475 if (errno == ETIMEDOUT) {
1476 /*
1477 * Call has timed out so we kill the kconsumerd_thread and return
1478 * an error.
1479 */
1480 ERR("The consumer thread was never ready. Killing it");
1481 ret = pthread_cancel(consumer_data->thread);
1482 if (ret < 0) {
1483 PERROR("pthread_cancel consumer thread");
1484 }
1485 } else {
1486 PERROR("semaphore wait failed consumer thread");
1487 }
1488 goto error;
1489 }
1490
1491 pthread_mutex_lock(&consumer_data->pid_mutex);
1492 if (consumer_data->pid == 0) {
1493 ERR("Kconsumerd did not start");
1494 pthread_mutex_unlock(&consumer_data->pid_mutex);
1495 goto error;
1496 }
1497 pthread_mutex_unlock(&consumer_data->pid_mutex);
1498
1499 return 0;
1500
1501 error:
1502 return ret;
1503 }
1504
1505 /*
1506 * Join consumer thread
1507 */
1508 static int join_consumer_thread(struct consumer_data *consumer_data)
1509 {
1510 void *status;
1511 int ret;
1512
1513 if (consumer_data->pid != 0) {
1514 ret = kill(consumer_data->pid, SIGTERM);
1515 if (ret) {
1516 ERR("Error killing consumer daemon");
1517 return ret;
1518 }
1519 return pthread_join(consumer_data->thread, &status);
1520 } else {
1521 return 0;
1522 }
1523 }
1524
1525 /*
1526 * Fork and exec a consumer daemon (consumerd).
1527 *
1528 * Return pid if successful else -1.
1529 */
1530 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
1531 {
1532 int ret;
1533 pid_t pid;
1534 const char *consumer_to_use;
1535 const char *verbosity;
1536 struct stat st;
1537
1538 DBG("Spawning consumerd");
1539
1540 pid = fork();
1541 if (pid == 0) {
1542 /*
1543 * Exec consumerd.
1544 */
1545 if (opt_verbose_consumer) {
1546 verbosity = "--verbose";
1547 } else {
1548 verbosity = "--quiet";
1549 }
1550 switch (consumer_data->type) {
1551 case LTTNG_CONSUMER_KERNEL:
1552 /*
1553 * Find out which consumerd to execute. We will first try the
1554 * 64-bit path, then the sessiond's installation directory, and
1555 * fallback on the 32-bit one,
1556 */
1557 DBG3("Looking for a kernel consumer at these locations:");
1558 DBG3(" 1) %s", consumerd64_bin);
1559 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, CONSUMERD_FILE);
1560 DBG3(" 3) %s", consumerd32_bin);
1561 if (stat(consumerd64_bin, &st) == 0) {
1562 DBG3("Found location #1");
1563 consumer_to_use = consumerd64_bin;
1564 } else if (stat(INSTALL_BIN_PATH "/" CONSUMERD_FILE, &st) == 0) {
1565 DBG3("Found location #2");
1566 consumer_to_use = INSTALL_BIN_PATH "/" CONSUMERD_FILE;
1567 } else if (stat(consumerd32_bin, &st) == 0) {
1568 DBG3("Found location #3");
1569 consumer_to_use = consumerd32_bin;
1570 } else {
1571 DBG("Could not find any valid consumerd executable");
1572 break;
1573 }
1574 DBG("Using kernel consumer at: %s", consumer_to_use);
1575 execl(consumer_to_use,
1576 "lttng-consumerd", verbosity, "-k",
1577 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1578 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1579 NULL);
1580 break;
1581 case LTTNG_CONSUMER64_UST:
1582 {
1583 char *tmpnew = NULL;
1584
1585 if (consumerd64_libdir[0] != '\0') {
1586 char *tmp;
1587 size_t tmplen;
1588
1589 tmp = getenv("LD_LIBRARY_PATH");
1590 if (!tmp) {
1591 tmp = "";
1592 }
1593 tmplen = strlen("LD_LIBRARY_PATH=")
1594 + strlen(consumerd64_libdir) + 1 /* : */ + strlen(tmp);
1595 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1596 if (!tmpnew) {
1597 ret = -ENOMEM;
1598 goto error;
1599 }
1600 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1601 strcat(tmpnew, consumerd64_libdir);
1602 if (tmp[0] != '\0') {
1603 strcat(tmpnew, ":");
1604 strcat(tmpnew, tmp);
1605 }
1606 ret = putenv(tmpnew);
1607 if (ret) {
1608 ret = -errno;
1609 goto error;
1610 }
1611 }
1612 DBG("Using 64-bit UST consumer at: %s", consumerd64_bin);
1613 ret = execl(consumerd64_bin, "lttng-consumerd", verbosity, "-u",
1614 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1615 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1616 NULL);
1617 if (consumerd64_libdir[0] != '\0') {
1618 free(tmpnew);
1619 }
1620 if (ret) {
1621 goto error;
1622 }
1623 break;
1624 }
1625 case LTTNG_CONSUMER32_UST:
1626 {
1627 char *tmpnew = NULL;
1628
1629 if (consumerd32_libdir[0] != '\0') {
1630 char *tmp;
1631 size_t tmplen;
1632
1633 tmp = getenv("LD_LIBRARY_PATH");
1634 if (!tmp) {
1635 tmp = "";
1636 }
1637 tmplen = strlen("LD_LIBRARY_PATH=")
1638 + strlen(consumerd32_libdir) + 1 /* : */ + strlen(tmp);
1639 tmpnew = zmalloc(tmplen + 1 /* \0 */);
1640 if (!tmpnew) {
1641 ret = -ENOMEM;
1642 goto error;
1643 }
1644 strcpy(tmpnew, "LD_LIBRARY_PATH=");
1645 strcat(tmpnew, consumerd32_libdir);
1646 if (tmp[0] != '\0') {
1647 strcat(tmpnew, ":");
1648 strcat(tmpnew, tmp);
1649 }
1650 ret = putenv(tmpnew);
1651 if (ret) {
1652 ret = -errno;
1653 goto error;
1654 }
1655 }
1656 DBG("Using 32-bit UST consumer at: %s", consumerd32_bin);
1657 ret = execl(consumerd32_bin, "lttng-consumerd", verbosity, "-u",
1658 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
1659 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
1660 NULL);
1661 if (consumerd32_libdir[0] != '\0') {
1662 free(tmpnew);
1663 }
1664 if (ret) {
1665 goto error;
1666 }
1667 break;
1668 }
1669 default:
1670 perror("unknown consumer type");
1671 exit(EXIT_FAILURE);
1672 }
1673 if (errno != 0) {
1674 perror("kernel start consumer exec");
1675 }
1676 exit(EXIT_FAILURE);
1677 } else if (pid > 0) {
1678 ret = pid;
1679 } else {
1680 perror("start consumer fork");
1681 ret = -errno;
1682 }
1683 error:
1684 return ret;
1685 }
1686
1687 /*
1688 * Spawn the consumerd daemon and session daemon thread.
1689 */
1690 static int start_consumerd(struct consumer_data *consumer_data)
1691 {
1692 int ret;
1693
1694 pthread_mutex_lock(&consumer_data->pid_mutex);
1695 if (consumer_data->pid != 0) {
1696 pthread_mutex_unlock(&consumer_data->pid_mutex);
1697 goto end;
1698 }
1699
1700 ret = spawn_consumerd(consumer_data);
1701 if (ret < 0) {
1702 ERR("Spawning consumerd failed");
1703 pthread_mutex_unlock(&consumer_data->pid_mutex);
1704 goto error;
1705 }
1706
1707 /* Setting up the consumer_data pid */
1708 consumer_data->pid = ret;
1709 DBG2("Consumer pid %d", consumer_data->pid);
1710 pthread_mutex_unlock(&consumer_data->pid_mutex);
1711
1712 DBG2("Spawning consumer control thread");
1713 ret = spawn_consumer_thread(consumer_data);
1714 if (ret < 0) {
1715 ERR("Fatal error spawning consumer control thread");
1716 goto error;
1717 }
1718
1719 end:
1720 return 0;
1721
1722 error:
1723 return ret;
1724 }
1725
1726 /*
1727 * Check version of the lttng-modules.
1728 */
1729 static int validate_lttng_modules_version(void)
1730 {
1731 return kernel_validate_version(kernel_tracer_fd);
1732 }
1733
1734 /*
1735 * Setup necessary data for kernel tracer action.
1736 */
1737 static int init_kernel_tracer(void)
1738 {
1739 int ret;
1740
1741 /* Modprobe lttng kernel modules */
1742 ret = modprobe_lttng_control();
1743 if (ret < 0) {
1744 goto error;
1745 }
1746
1747 /* Open debugfs lttng */
1748 kernel_tracer_fd = open(module_proc_lttng, O_RDWR);
1749 if (kernel_tracer_fd < 0) {
1750 DBG("Failed to open %s", module_proc_lttng);
1751 ret = -1;
1752 goto error_open;
1753 }
1754
1755 /* Validate kernel version */
1756 ret = validate_lttng_modules_version();
1757 if (ret < 0) {
1758 goto error_version;
1759 }
1760
1761 ret = modprobe_lttng_data();
1762 if (ret < 0) {
1763 goto error_modules;
1764 }
1765
1766 DBG("Kernel tracer fd %d", kernel_tracer_fd);
1767 return 0;
1768
1769 error_version:
1770 modprobe_remove_lttng_control();
1771 close(kernel_tracer_fd);
1772 kernel_tracer_fd = 0;
1773 return LTTCOMM_KERN_VERSION;
1774
1775 error_modules:
1776 close(kernel_tracer_fd);
1777
1778 error_open:
1779 modprobe_remove_lttng_control();
1780
1781 error:
1782 WARN("No kernel tracer available");
1783 kernel_tracer_fd = 0;
1784 return LTTCOMM_KERN_NA;
1785 }
1786
1787 /*
1788 * Init tracing by creating trace directory and sending fds kernel consumer.
1789 */
1790 static int init_kernel_tracing(struct ltt_kernel_session *session)
1791 {
1792 int ret = 0;
1793
1794 if (session->consumer_fds_sent == 0) {
1795 /*
1796 * Assign default kernel consumer socket if no consumer assigned to the
1797 * kernel session. At this point, it's NOT suppose to be 0 but this is
1798 * an extra security check.
1799 */
1800 if (session->consumer_fd == 0) {
1801 session->consumer_fd = kconsumer_data.cmd_sock;
1802 }
1803
1804 ret = send_kconsumer_session_streams(&kconsumer_data, session);
1805 if (ret < 0) {
1806 ret = LTTCOMM_KERN_CONSUMER_FAIL;
1807 goto error;
1808 }
1809
1810 session->consumer_fds_sent = 1;
1811 }
1812
1813 error:
1814 return ret;
1815 }
1816
1817 /*
1818 * Create an UST session and add it to the session ust list.
1819 */
1820 static int create_ust_session(struct ltt_session *session,
1821 struct lttng_domain *domain)
1822 {
1823 struct ltt_ust_session *lus = NULL;
1824 int ret;
1825
1826 switch (domain->type) {
1827 case LTTNG_DOMAIN_UST:
1828 break;
1829 default:
1830 ret = LTTCOMM_UNKNOWN_DOMAIN;
1831 goto error;
1832 }
1833
1834 DBG("Creating UST session");
1835
1836 lus = trace_ust_create_session(session->path, session->id, domain);
1837 if (lus == NULL) {
1838 ret = LTTCOMM_UST_SESS_FAIL;
1839 goto error;
1840 }
1841
1842 ret = run_as_mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
1843 session->uid, session->gid);
1844 if (ret < 0) {
1845 if (ret != -EEXIST) {
1846 ERR("Trace directory creation error");
1847 ret = LTTCOMM_UST_SESS_FAIL;
1848 goto error;
1849 }
1850 }
1851
1852 /* The domain type dictate different actions on session creation */
1853 switch (domain->type) {
1854 case LTTNG_DOMAIN_UST:
1855 /* No ustctl for the global UST domain */
1856 break;
1857 default:
1858 ERR("Unknown UST domain on create session %d", domain->type);
1859 goto error;
1860 }
1861 lus->uid = session->uid;
1862 lus->gid = session->gid;
1863 session->ust_session = lus;
1864
1865 return LTTCOMM_OK;
1866
1867 error:
1868 free(lus);
1869 return ret;
1870 }
1871
1872 /*
1873 * Create a kernel tracer session then create the default channel.
1874 */
1875 static int create_kernel_session(struct ltt_session *session)
1876 {
1877 int ret;
1878
1879 DBG("Creating kernel session");
1880
1881 ret = kernel_create_session(session, kernel_tracer_fd);
1882 if (ret < 0) {
1883 ret = LTTCOMM_KERN_SESS_FAIL;
1884 goto error;
1885 }
1886
1887 /* Set kernel consumer socket fd */
1888 if (kconsumer_data.cmd_sock) {
1889 session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
1890 }
1891
1892 ret = run_as_mkdir_recursive(session->kernel_session->trace_path,
1893 S_IRWXU | S_IRWXG, session->uid, session->gid);
1894 if (ret < 0) {
1895 if (ret != -EEXIST) {
1896 ERR("Trace directory creation error");
1897 goto error;
1898 }
1899 }
1900 session->kernel_session->uid = session->uid;
1901 session->kernel_session->gid = session->gid;
1902
1903 error:
1904 return ret;
1905 }
1906
1907 /*
1908 * Check if the UID or GID match the session. Root user has access to all
1909 * sessions.
1910 */
1911 static int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
1912 {
1913 if (uid != session->uid && gid != session->gid && uid != 0) {
1914 return 0;
1915 } else {
1916 return 1;
1917 }
1918 }
1919
1920 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
1921 {
1922 unsigned int i = 0;
1923 struct ltt_session *session;
1924
1925 DBG("Counting number of available session for UID %d GID %d",
1926 uid, gid);
1927 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1928 /*
1929 * Only list the sessions the user can control.
1930 */
1931 if (!session_access_ok(session, uid, gid)) {
1932 continue;
1933 }
1934 i++;
1935 }
1936 return i;
1937 }
1938
1939 /*
1940 * Using the session list, filled a lttng_session array to send back to the
1941 * client for session listing.
1942 *
1943 * The session list lock MUST be acquired before calling this function. Use
1944 * session_lock_list() and session_unlock_list().
1945 */
1946 static void list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
1947 gid_t gid)
1948 {
1949 unsigned int i = 0;
1950 struct ltt_session *session;
1951
1952 DBG("Getting all available session for UID %d GID %d",
1953 uid, gid);
1954 /*
1955 * Iterate over session list and append data after the control struct in
1956 * the buffer.
1957 */
1958 cds_list_for_each_entry(session, &session_list_ptr->head, list) {
1959 /*
1960 * Only list the sessions the user can control.
1961 */
1962 if (!session_access_ok(session, uid, gid)) {
1963 continue;
1964 }
1965 strncpy(sessions[i].path, session->path, PATH_MAX);
1966 sessions[i].path[PATH_MAX - 1] = '\0';
1967 strncpy(sessions[i].name, session->name, NAME_MAX);
1968 sessions[i].name[NAME_MAX - 1] = '\0';
1969 sessions[i].enabled = session->enabled;
1970 i++;
1971 }
1972 }
1973
1974 /*
1975 * Fill lttng_channel array of all channels.
1976 */
1977 static void list_lttng_channels(int domain, struct ltt_session *session,
1978 struct lttng_channel *channels)
1979 {
1980 int i = 0;
1981 struct ltt_kernel_channel *kchan;
1982
1983 DBG("Listing channels for session %s", session->name);
1984
1985 switch (domain) {
1986 case LTTNG_DOMAIN_KERNEL:
1987 /* Kernel channels */
1988 if (session->kernel_session != NULL) {
1989 cds_list_for_each_entry(kchan,
1990 &session->kernel_session->channel_list.head, list) {
1991 /* Copy lttng_channel struct to array */
1992 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
1993 channels[i].enabled = kchan->enabled;
1994 i++;
1995 }
1996 }
1997 break;
1998 case LTTNG_DOMAIN_UST:
1999 {
2000 struct lttng_ht_iter iter;
2001 struct ltt_ust_channel *uchan;
2002
2003 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
2004 &iter.iter, uchan, node.node) {
2005 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
2006 channels[i].attr.overwrite = uchan->attr.overwrite;
2007 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
2008 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
2009 channels[i].attr.switch_timer_interval =
2010 uchan->attr.switch_timer_interval;
2011 channels[i].attr.read_timer_interval =
2012 uchan->attr.read_timer_interval;
2013 channels[i].enabled = uchan->enabled;
2014 switch (uchan->attr.output) {
2015 case LTTNG_UST_MMAP:
2016 default:
2017 channels[i].attr.output = LTTNG_EVENT_MMAP;
2018 break;
2019 }
2020 i++;
2021 }
2022 break;
2023 }
2024 default:
2025 break;
2026 }
2027 }
2028
2029 /*
2030 * Create a list of ust global domain events.
2031 */
2032 static int list_lttng_ust_global_events(char *channel_name,
2033 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
2034 {
2035 int i = 0, ret = 0;
2036 unsigned int nb_event = 0;
2037 struct lttng_ht_iter iter;
2038 struct lttng_ht_node_str *node;
2039 struct ltt_ust_channel *uchan;
2040 struct ltt_ust_event *uevent;
2041 struct lttng_event *tmp;
2042
2043 DBG("Listing UST global events for channel %s", channel_name);
2044
2045 rcu_read_lock();
2046
2047 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
2048 node = lttng_ht_iter_get_node_str(&iter);
2049 if (node == NULL) {
2050 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
2051 goto error;
2052 }
2053
2054 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
2055
2056 nb_event += lttng_ht_get_count(uchan->events);
2057
2058 if (nb_event == 0) {
2059 ret = nb_event;
2060 goto error;
2061 }
2062
2063 DBG3("Listing UST global %d events", nb_event);
2064
2065 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
2066 if (tmp == NULL) {
2067 ret = -LTTCOMM_FATAL;
2068 goto error;
2069 }
2070
2071 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
2072 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
2073 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2074 tmp[i].enabled = uevent->enabled;
2075 switch (uevent->attr.instrumentation) {
2076 case LTTNG_UST_TRACEPOINT:
2077 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
2078 break;
2079 case LTTNG_UST_PROBE:
2080 tmp[i].type = LTTNG_EVENT_PROBE;
2081 break;
2082 case LTTNG_UST_FUNCTION:
2083 tmp[i].type = LTTNG_EVENT_FUNCTION;
2084 break;
2085 }
2086 tmp[i].loglevel = uevent->attr.loglevel;
2087 switch (uevent->attr.loglevel_type) {
2088 case LTTNG_UST_LOGLEVEL_ALL:
2089 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2090 break;
2091 case LTTNG_UST_LOGLEVEL_RANGE:
2092 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
2093 break;
2094 case LTTNG_UST_LOGLEVEL_SINGLE:
2095 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
2096 break;
2097 }
2098 i++;
2099 }
2100
2101 ret = nb_event;
2102 *events = tmp;
2103
2104 error:
2105 rcu_read_unlock();
2106 return ret;
2107 }
2108
2109 /*
2110 * Fill lttng_event array of all kernel events in the channel.
2111 */
2112 static int list_lttng_kernel_events(char *channel_name,
2113 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
2114 {
2115 int i = 0, ret;
2116 unsigned int nb_event;
2117 struct ltt_kernel_event *event;
2118 struct ltt_kernel_channel *kchan;
2119
2120 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
2121 if (kchan == NULL) {
2122 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2123 goto error;
2124 }
2125
2126 nb_event = kchan->event_count;
2127
2128 DBG("Listing events for channel %s", kchan->channel->name);
2129
2130 if (nb_event == 0) {
2131 ret = nb_event;
2132 goto error;
2133 }
2134
2135 *events = zmalloc(nb_event * sizeof(struct lttng_event));
2136 if (*events == NULL) {
2137 ret = LTTCOMM_FATAL;
2138 goto error;
2139 }
2140
2141 /* Kernel channels */
2142 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
2143 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
2144 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
2145 (*events)[i].enabled = event->enabled;
2146 switch (event->event->instrumentation) {
2147 case LTTNG_KERNEL_TRACEPOINT:
2148 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
2149 break;
2150 case LTTNG_KERNEL_KPROBE:
2151 case LTTNG_KERNEL_KRETPROBE:
2152 (*events)[i].type = LTTNG_EVENT_PROBE;
2153 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
2154 sizeof(struct lttng_kernel_kprobe));
2155 break;
2156 case LTTNG_KERNEL_FUNCTION:
2157 (*events)[i].type = LTTNG_EVENT_FUNCTION;
2158 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
2159 sizeof(struct lttng_kernel_function));
2160 break;
2161 case LTTNG_KERNEL_NOOP:
2162 (*events)[i].type = LTTNG_EVENT_NOOP;
2163 break;
2164 case LTTNG_KERNEL_SYSCALL:
2165 (*events)[i].type = LTTNG_EVENT_SYSCALL;
2166 break;
2167 case LTTNG_KERNEL_ALL:
2168 assert(0);
2169 break;
2170 }
2171 i++;
2172 }
2173
2174 return nb_event;
2175
2176 error:
2177 return ret;
2178 }
2179
2180 /*
2181 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
2182 */
2183 static int cmd_disable_channel(struct ltt_session *session,
2184 int domain, char *channel_name)
2185 {
2186 int ret;
2187 struct ltt_ust_session *usess;
2188
2189 usess = session->ust_session;
2190
2191 switch (domain) {
2192 case LTTNG_DOMAIN_KERNEL:
2193 {
2194 ret = channel_kernel_disable(session->kernel_session,
2195 channel_name);
2196 if (ret != LTTCOMM_OK) {
2197 goto error;
2198 }
2199
2200 kernel_wait_quiescent(kernel_tracer_fd);
2201 break;
2202 }
2203 case LTTNG_DOMAIN_UST:
2204 {
2205 struct ltt_ust_channel *uchan;
2206 struct lttng_ht *chan_ht;
2207
2208 chan_ht = usess->domain_global.channels;
2209
2210 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
2211 if (uchan == NULL) {
2212 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2213 goto error;
2214 }
2215
2216 ret = channel_ust_disable(usess, domain, uchan);
2217 if (ret != LTTCOMM_OK) {
2218 goto error;
2219 }
2220 break;
2221 }
2222 #if 0
2223 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2224 case LTTNG_DOMAIN_UST_EXEC_NAME:
2225 case LTTNG_DOMAIN_UST_PID:
2226 #endif
2227 default:
2228 ret = LTTCOMM_UNKNOWN_DOMAIN;
2229 goto error;
2230 }
2231
2232 ret = LTTCOMM_OK;
2233
2234 error:
2235 return ret;
2236 }
2237
2238 /*
2239 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
2240 */
2241 static int cmd_enable_channel(struct ltt_session *session,
2242 int domain, struct lttng_channel *attr)
2243 {
2244 int ret;
2245 struct ltt_ust_session *usess = session->ust_session;
2246 struct lttng_ht *chan_ht;
2247
2248 DBG("Enabling channel %s for session %s", attr->name, session->name);
2249
2250 switch (domain) {
2251 case LTTNG_DOMAIN_KERNEL:
2252 {
2253 struct ltt_kernel_channel *kchan;
2254
2255 kchan = trace_kernel_get_channel_by_name(attr->name,
2256 session->kernel_session);
2257 if (kchan == NULL) {
2258 ret = channel_kernel_create(session->kernel_session,
2259 attr, kernel_poll_pipe[1]);
2260 } else {
2261 ret = channel_kernel_enable(session->kernel_session, kchan);
2262 }
2263
2264 if (ret != LTTCOMM_OK) {
2265 goto error;
2266 }
2267
2268 kernel_wait_quiescent(kernel_tracer_fd);
2269 break;
2270 }
2271 case LTTNG_DOMAIN_UST:
2272 {
2273 struct ltt_ust_channel *uchan;
2274
2275 chan_ht = usess->domain_global.channels;
2276
2277 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
2278 if (uchan == NULL) {
2279 ret = channel_ust_create(usess, domain, attr);
2280 } else {
2281 ret = channel_ust_enable(usess, domain, uchan);
2282 }
2283 break;
2284 }
2285 #if 0
2286 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2287 case LTTNG_DOMAIN_UST_EXEC_NAME:
2288 case LTTNG_DOMAIN_UST_PID:
2289 #endif
2290 default:
2291 ret = LTTCOMM_UNKNOWN_DOMAIN;
2292 goto error;
2293 }
2294
2295 error:
2296 return ret;
2297 }
2298
2299 /*
2300 * Command LTTNG_DISABLE_EVENT processed by the client thread.
2301 */
2302 static int cmd_disable_event(struct ltt_session *session, int domain,
2303 char *channel_name, char *event_name)
2304 {
2305 int ret;
2306
2307 switch (domain) {
2308 case LTTNG_DOMAIN_KERNEL:
2309 {
2310 struct ltt_kernel_channel *kchan;
2311 struct ltt_kernel_session *ksess;
2312
2313 ksess = session->kernel_session;
2314
2315 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2316 if (kchan == NULL) {
2317 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2318 goto error;
2319 }
2320
2321 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
2322 if (ret != LTTCOMM_OK) {
2323 goto error;
2324 }
2325
2326 kernel_wait_quiescent(kernel_tracer_fd);
2327 break;
2328 }
2329 case LTTNG_DOMAIN_UST:
2330 {
2331 struct ltt_ust_channel *uchan;
2332 struct ltt_ust_session *usess;
2333
2334 usess = session->ust_session;
2335
2336 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2337 channel_name);
2338 if (uchan == NULL) {
2339 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2340 goto error;
2341 }
2342
2343 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
2344 if (ret != LTTCOMM_OK) {
2345 goto error;
2346 }
2347
2348 DBG3("Disable UST event %s in channel %s completed", event_name,
2349 channel_name);
2350 break;
2351 }
2352 #if 0
2353 case LTTNG_DOMAIN_UST_EXEC_NAME:
2354 case LTTNG_DOMAIN_UST_PID:
2355 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2356 #endif
2357 default:
2358 ret = LTTCOMM_UND;
2359 goto error;
2360 }
2361
2362 ret = LTTCOMM_OK;
2363
2364 error:
2365 return ret;
2366 }
2367
2368 /*
2369 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
2370 */
2371 static int cmd_disable_event_all(struct ltt_session *session, int domain,
2372 char *channel_name)
2373 {
2374 int ret;
2375
2376 switch (domain) {
2377 case LTTNG_DOMAIN_KERNEL:
2378 {
2379 struct ltt_kernel_session *ksess;
2380 struct ltt_kernel_channel *kchan;
2381
2382 ksess = session->kernel_session;
2383
2384 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
2385 if (kchan == NULL) {
2386 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
2387 goto error;
2388 }
2389
2390 ret = event_kernel_disable_all(ksess, kchan);
2391 if (ret != LTTCOMM_OK) {
2392 goto error;
2393 }
2394
2395 kernel_wait_quiescent(kernel_tracer_fd);
2396 break;
2397 }
2398 case LTTNG_DOMAIN_UST:
2399 {
2400 struct ltt_ust_session *usess;
2401 struct ltt_ust_channel *uchan;
2402
2403 usess = session->ust_session;
2404
2405 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2406 channel_name);
2407 if (uchan == NULL) {
2408 ret = LTTCOMM_UST_CHAN_NOT_FOUND;
2409 goto error;
2410 }
2411
2412 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
2413 if (ret != 0) {
2414 goto error;
2415 }
2416
2417 DBG3("Disable all UST events in channel %s completed", channel_name);
2418
2419 break;
2420 }
2421 #if 0
2422 case LTTNG_DOMAIN_UST_EXEC_NAME:
2423 case LTTNG_DOMAIN_UST_PID:
2424 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2425 #endif
2426 default:
2427 ret = LTTCOMM_UND;
2428 goto error;
2429 }
2430
2431 ret = LTTCOMM_OK;
2432
2433 error:
2434 return ret;
2435 }
2436
2437 /*
2438 * Command LTTNG_ADD_CONTEXT processed by the client thread.
2439 */
2440 static int cmd_add_context(struct ltt_session *session, int domain,
2441 char *channel_name, char *event_name, struct lttng_event_context *ctx)
2442 {
2443 int ret;
2444
2445 switch (domain) {
2446 case LTTNG_DOMAIN_KERNEL:
2447 /* Add kernel context to kernel tracer */
2448 ret = context_kernel_add(session->kernel_session, ctx,
2449 event_name, channel_name);
2450 if (ret != LTTCOMM_OK) {
2451 goto error;
2452 }
2453 break;
2454 case LTTNG_DOMAIN_UST:
2455 {
2456 struct ltt_ust_session *usess = session->ust_session;
2457
2458 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
2459 if (ret != LTTCOMM_OK) {
2460 goto error;
2461 }
2462 break;
2463 }
2464 #if 0
2465 case LTTNG_DOMAIN_UST_EXEC_NAME:
2466 case LTTNG_DOMAIN_UST_PID:
2467 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2468 #endif
2469 default:
2470 ret = LTTCOMM_UND;
2471 goto error;
2472 }
2473
2474 ret = LTTCOMM_OK;
2475
2476 error:
2477 return ret;
2478 }
2479
2480 /*
2481 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2482 */
2483 static int cmd_enable_event(struct ltt_session *session, int domain,
2484 char *channel_name, struct lttng_event *event)
2485 {
2486 int ret;
2487 struct lttng_channel *attr;
2488 struct ltt_ust_session *usess = session->ust_session;
2489
2490 switch (domain) {
2491 case LTTNG_DOMAIN_KERNEL:
2492 {
2493 struct ltt_kernel_channel *kchan;
2494
2495 kchan = trace_kernel_get_channel_by_name(channel_name,
2496 session->kernel_session);
2497 if (kchan == NULL) {
2498 attr = channel_new_default_attr(domain);
2499 if (attr == NULL) {
2500 ret = LTTCOMM_FATAL;
2501 goto error;
2502 }
2503 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2504
2505 /* This call will notify the kernel thread */
2506 ret = channel_kernel_create(session->kernel_session,
2507 attr, kernel_poll_pipe[1]);
2508 if (ret != LTTCOMM_OK) {
2509 free(attr);
2510 goto error;
2511 }
2512 free(attr);
2513 }
2514
2515 /* Get the newly created kernel channel pointer */
2516 kchan = trace_kernel_get_channel_by_name(channel_name,
2517 session->kernel_session);
2518 if (kchan == NULL) {
2519 /* This sould not happen... */
2520 ret = LTTCOMM_FATAL;
2521 goto error;
2522 }
2523
2524 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
2525 event);
2526 if (ret != LTTCOMM_OK) {
2527 goto error;
2528 }
2529
2530 kernel_wait_quiescent(kernel_tracer_fd);
2531 break;
2532 }
2533 case LTTNG_DOMAIN_UST:
2534 {
2535 struct lttng_channel *attr;
2536 struct ltt_ust_channel *uchan;
2537
2538 /* Get channel from global UST domain */
2539 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2540 channel_name);
2541 if (uchan == NULL) {
2542 /* Create default channel */
2543 attr = channel_new_default_attr(domain);
2544 if (attr == NULL) {
2545 ret = LTTCOMM_FATAL;
2546 goto error;
2547 }
2548 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2549 attr->name[NAME_MAX - 1] = '\0';
2550
2551 ret = channel_ust_create(usess, domain, attr);
2552 if (ret != LTTCOMM_OK) {
2553 free(attr);
2554 goto error;
2555 }
2556 free(attr);
2557
2558 /* Get the newly created channel reference back */
2559 uchan = trace_ust_find_channel_by_name(
2560 usess->domain_global.channels, channel_name);
2561 if (uchan == NULL) {
2562 /* Something is really wrong */
2563 ret = LTTCOMM_FATAL;
2564 goto error;
2565 }
2566 }
2567
2568 /* At this point, the session and channel exist on the tracer */
2569 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
2570 if (ret != LTTCOMM_OK) {
2571 goto error;
2572 }
2573 break;
2574 }
2575 #if 0
2576 case LTTNG_DOMAIN_UST_EXEC_NAME:
2577 case LTTNG_DOMAIN_UST_PID:
2578 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2579 #endif
2580 default:
2581 ret = LTTCOMM_UND;
2582 goto error;
2583 }
2584
2585 ret = LTTCOMM_OK;
2586
2587 error:
2588 return ret;
2589 }
2590
2591 /*
2592 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
2593 */
2594 static int cmd_enable_event_all(struct ltt_session *session, int domain,
2595 char *channel_name, int event_type)
2596 {
2597 int ret;
2598 struct ltt_kernel_channel *kchan;
2599
2600 switch (domain) {
2601 case LTTNG_DOMAIN_KERNEL:
2602 kchan = trace_kernel_get_channel_by_name(channel_name,
2603 session->kernel_session);
2604 if (kchan == NULL) {
2605 /* This call will notify the kernel thread */
2606 ret = channel_kernel_create(session->kernel_session, NULL,
2607 kernel_poll_pipe[1]);
2608 if (ret != LTTCOMM_OK) {
2609 goto error;
2610 }
2611
2612 /* Get the newly created kernel channel pointer */
2613 kchan = trace_kernel_get_channel_by_name(channel_name,
2614 session->kernel_session);
2615 if (kchan == NULL) {
2616 /* This sould not happen... */
2617 ret = LTTCOMM_FATAL;
2618 goto error;
2619 }
2620
2621 }
2622
2623 switch (event_type) {
2624 case LTTNG_EVENT_SYSCALL:
2625 ret = event_kernel_enable_all_syscalls(session->kernel_session,
2626 kchan, kernel_tracer_fd);
2627 break;
2628 case LTTNG_EVENT_TRACEPOINT:
2629 /*
2630 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
2631 * events already registered to the channel.
2632 */
2633 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
2634 kchan, kernel_tracer_fd);
2635 break;
2636 case LTTNG_EVENT_ALL:
2637 /* Enable syscalls and tracepoints */
2638 ret = event_kernel_enable_all(session->kernel_session,
2639 kchan, kernel_tracer_fd);
2640 break;
2641 default:
2642 ret = LTTCOMM_KERN_ENABLE_FAIL;
2643 goto error;
2644 }
2645
2646 /* Manage return value */
2647 if (ret != LTTCOMM_OK) {
2648 goto error;
2649 }
2650
2651 kernel_wait_quiescent(kernel_tracer_fd);
2652 break;
2653 case LTTNG_DOMAIN_UST:
2654 {
2655 struct lttng_channel *attr;
2656 struct ltt_ust_channel *uchan;
2657 struct ltt_ust_session *usess = session->ust_session;
2658
2659 /* Get channel from global UST domain */
2660 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2661 channel_name);
2662 if (uchan == NULL) {
2663 /* Create default channel */
2664 attr = channel_new_default_attr(domain);
2665 if (attr == NULL) {
2666 ret = LTTCOMM_FATAL;
2667 goto error;
2668 }
2669 snprintf(attr->name, NAME_MAX, "%s", channel_name);
2670 attr->name[NAME_MAX - 1] = '\0';
2671
2672 /* Use the internal command enable channel */
2673 ret = channel_ust_create(usess, domain, attr);
2674 if (ret != LTTCOMM_OK) {
2675 free(attr);
2676 goto error;
2677 }
2678 free(attr);
2679
2680 /* Get the newly created channel reference back */
2681 uchan = trace_ust_find_channel_by_name(
2682 usess->domain_global.channels, channel_name);
2683 if (uchan == NULL) {
2684 /* Something is really wrong */
2685 ret = LTTCOMM_FATAL;
2686 goto error;
2687 }
2688 }
2689
2690 /* At this point, the session and channel exist on the tracer */
2691
2692 switch (event_type) {
2693 case LTTNG_EVENT_ALL:
2694 case LTTNG_EVENT_TRACEPOINT:
2695 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
2696 if (ret != LTTCOMM_OK) {
2697 goto error;
2698 }
2699 break;
2700 default:
2701 ret = LTTCOMM_UST_ENABLE_FAIL;
2702 goto error;
2703 }
2704
2705 /* Manage return value */
2706 if (ret != LTTCOMM_OK) {
2707 goto error;
2708 }
2709
2710 break;
2711 }
2712 #if 0
2713 case LTTNG_DOMAIN_UST_EXEC_NAME:
2714 case LTTNG_DOMAIN_UST_PID:
2715 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
2716 #endif
2717 default:
2718 ret = LTTCOMM_UND;
2719 goto error;
2720 }
2721
2722 ret = LTTCOMM_OK;
2723
2724 error:
2725 return ret;
2726 }
2727
2728 /*
2729 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2730 */
2731 static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
2732 {
2733 int ret;
2734 ssize_t nb_events = 0;
2735
2736 switch (domain) {
2737 case LTTNG_DOMAIN_KERNEL:
2738 nb_events = kernel_list_events(kernel_tracer_fd, events);
2739 if (nb_events < 0) {
2740 ret = LTTCOMM_KERN_LIST_FAIL;
2741 goto error;
2742 }
2743 break;
2744 case LTTNG_DOMAIN_UST:
2745 nb_events = ust_app_list_events(events);
2746 if (nb_events < 0) {
2747 ret = LTTCOMM_UST_LIST_FAIL;
2748 goto error;
2749 }
2750 break;
2751 default:
2752 ret = LTTCOMM_UND;
2753 goto error;
2754 }
2755
2756 return nb_events;
2757
2758 error:
2759 /* Return negative value to differentiate return code */
2760 return -ret;
2761 }
2762
2763 /*
2764 * Command LTTNG_START_TRACE processed by the client thread.
2765 */
2766 static int cmd_start_trace(struct ltt_session *session)
2767 {
2768 int ret;
2769 struct ltt_kernel_session *ksession;
2770 struct ltt_ust_session *usess;
2771
2772 /* Short cut */
2773 ksession = session->kernel_session;
2774 usess = session->ust_session;
2775
2776 if (session->enabled) {
2777 ret = LTTCOMM_UST_START_FAIL;
2778 goto error;
2779 }
2780
2781 session->enabled = 1;
2782
2783 /* Kernel tracing */
2784 if (ksession != NULL) {
2785 struct ltt_kernel_channel *kchan;
2786
2787 /* Open kernel metadata */
2788 if (ksession->metadata == NULL) {
2789 ret = kernel_open_metadata(ksession, ksession->trace_path);
2790 if (ret < 0) {
2791 ret = LTTCOMM_KERN_META_FAIL;
2792 goto error;
2793 }
2794 }
2795
2796 /* Open kernel metadata stream */
2797 if (ksession->metadata_stream_fd == 0) {
2798 ret = kernel_open_metadata_stream(ksession);
2799 if (ret < 0) {
2800 ERR("Kernel create metadata stream failed");
2801 ret = LTTCOMM_KERN_STREAM_FAIL;
2802 goto error;
2803 }
2804 }
2805
2806 /* For each channel */
2807 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2808 if (kchan->stream_count == 0) {
2809 ret = kernel_open_channel_stream(kchan);
2810 if (ret < 0) {
2811 ret = LTTCOMM_KERN_STREAM_FAIL;
2812 goto error;
2813 }
2814 /* Update the stream global counter */
2815 ksession->stream_count_global += ret;
2816 }
2817 }
2818
2819 /* Setup kernel consumer socket and send fds to it */
2820 ret = init_kernel_tracing(ksession);
2821 if (ret < 0) {
2822 ret = LTTCOMM_KERN_START_FAIL;
2823 goto error;
2824 }
2825
2826 /* This start the kernel tracing */
2827 ret = kernel_start_session(ksession);
2828 if (ret < 0) {
2829 ret = LTTCOMM_KERN_START_FAIL;
2830 goto error;
2831 }
2832
2833 /* Quiescent wait after starting trace */
2834 kernel_wait_quiescent(kernel_tracer_fd);
2835 }
2836
2837 /* Flag session that trace should start automatically */
2838 if (usess) {
2839 usess->start_trace = 1;
2840
2841 ret = ust_app_start_trace_all(usess);
2842 if (ret < 0) {
2843 ret = LTTCOMM_UST_START_FAIL;
2844 goto error;
2845 }
2846 }
2847
2848 ret = LTTCOMM_OK;
2849
2850 error:
2851 return ret;
2852 }
2853
2854 /*
2855 * Command LTTNG_STOP_TRACE processed by the client thread.
2856 */
2857 static int cmd_stop_trace(struct ltt_session *session)
2858 {
2859 int ret;
2860 struct ltt_kernel_channel *kchan;
2861 struct ltt_kernel_session *ksession;
2862 struct ltt_ust_session *usess;
2863
2864 /* Short cut */
2865 ksession = session->kernel_session;
2866 usess = session->ust_session;
2867
2868 if (!session->enabled) {
2869 ret = LTTCOMM_UST_STOP_FAIL;
2870 goto error;
2871 }
2872
2873 session->enabled = 0;
2874
2875 /* Kernel tracer */
2876 if (ksession != NULL) {
2877 DBG("Stop kernel tracing");
2878
2879 /* Flush all buffers before stopping */
2880 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2881 if (ret < 0) {
2882 ERR("Kernel metadata flush failed");
2883 }
2884
2885 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2886 ret = kernel_flush_buffer(kchan);
2887 if (ret < 0) {
2888 ERR("Kernel flush buffer error");
2889 }
2890 }
2891
2892 ret = kernel_stop_session(ksession);
2893 if (ret < 0) {
2894 ret = LTTCOMM_KERN_STOP_FAIL;
2895 goto error;
2896 }
2897
2898 kernel_wait_quiescent(kernel_tracer_fd);
2899 }
2900
2901 if (usess) {
2902 usess->start_trace = 0;
2903
2904 ret = ust_app_stop_trace_all(usess);
2905 if (ret < 0) {
2906 ret = LTTCOMM_UST_STOP_FAIL;
2907 goto error;
2908 }
2909 }
2910
2911 ret = LTTCOMM_OK;
2912
2913 error:
2914 return ret;
2915 }
2916
2917 /*
2918 * Command LTTNG_CREATE_SESSION processed by the client thread.
2919 */
2920 static int cmd_create_session(char *name, char *path, lttng_sock_cred *creds)
2921 {
2922 int ret;
2923
2924 ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
2925 LTTNG_SOCK_GET_GID_CRED(creds));
2926 if (ret != LTTCOMM_OK) {
2927 goto error;
2928 }
2929
2930 ret = LTTCOMM_OK;
2931
2932 error:
2933 return ret;
2934 }
2935
2936 /*
2937 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2938 */
2939 static int cmd_destroy_session(struct ltt_session *session, char *name)
2940 {
2941 int ret;
2942
2943 /* Clean kernel session teardown */
2944 teardown_kernel_session(session);
2945 /* UST session teardown */
2946 teardown_ust_session(session);
2947
2948 /*
2949 * Must notify the kernel thread here to update it's poll setin order
2950 * to remove the channel(s)' fd just destroyed.
2951 */
2952 ret = notify_thread_pipe(kernel_poll_pipe[1]);
2953 if (ret < 0) {
2954 perror("write kernel poll pipe");
2955 }
2956
2957 ret = session_destroy(session);
2958
2959 return ret;
2960 }
2961
2962 /*
2963 * Command LTTNG_CALIBRATE processed by the client thread.
2964 */
2965 static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
2966 {
2967 int ret;
2968
2969 switch (domain) {
2970 case LTTNG_DOMAIN_KERNEL:
2971 {
2972 struct lttng_kernel_calibrate kcalibrate;
2973
2974 kcalibrate.type = calibrate->type;
2975 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
2976 if (ret < 0) {
2977 ret = LTTCOMM_KERN_ENABLE_FAIL;
2978 goto error;
2979 }
2980 break;
2981 }
2982 case LTTNG_DOMAIN_UST:
2983 {
2984 struct lttng_ust_calibrate ucalibrate;
2985
2986 ucalibrate.type = calibrate->type;
2987 ret = ust_app_calibrate_glb(&ucalibrate);
2988 if (ret < 0) {
2989 ret = LTTCOMM_UST_CALIBRATE_FAIL;
2990 goto error;
2991 }
2992 break;
2993 }
2994 default:
2995 ret = LTTCOMM_UND;
2996 goto error;
2997 }
2998
2999 ret = LTTCOMM_OK;
3000
3001 error:
3002 return ret;
3003 }
3004
3005 /*
3006 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3007 */
3008 static int cmd_register_consumer(struct ltt_session *session, int domain,
3009 char *sock_path)
3010 {
3011 int ret, sock;
3012
3013 switch (domain) {
3014 case LTTNG_DOMAIN_KERNEL:
3015 /* Can't register a consumer if there is already one */
3016 if (session->kernel_session->consumer_fds_sent != 0) {
3017 ret = LTTCOMM_KERN_CONSUMER_FAIL;
3018 goto error;
3019 }
3020
3021 sock = lttcomm_connect_unix_sock(sock_path);
3022 if (sock < 0) {
3023 ret = LTTCOMM_CONNECT_FAIL;
3024 goto error;
3025 }
3026
3027 session->kernel_session->consumer_fd = sock;
3028 break;
3029 default:
3030 /* TODO: Userspace tracing */
3031 ret = LTTCOMM_UND;
3032 goto error;
3033 }
3034
3035 ret = LTTCOMM_OK;
3036
3037 error:
3038 return ret;
3039 }
3040
3041 /*
3042 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3043 */
3044 static ssize_t cmd_list_domains(struct ltt_session *session,
3045 struct lttng_domain **domains)
3046 {
3047 int ret, index = 0;
3048 ssize_t nb_dom = 0;
3049
3050 if (session->kernel_session != NULL) {
3051 DBG3("Listing domains found kernel domain");
3052 nb_dom++;
3053 }
3054
3055 if (session->ust_session != NULL) {
3056 DBG3("Listing domains found UST global domain");
3057 nb_dom++;
3058 }
3059
3060 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3061 if (*domains == NULL) {
3062 ret = -LTTCOMM_FATAL;
3063 goto error;
3064 }
3065
3066 if (session->kernel_session != NULL) {
3067 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3068 index++;
3069 }
3070
3071 if (session->ust_session != NULL) {
3072 (*domains)[index].type = LTTNG_DOMAIN_UST;
3073 index++;
3074 }
3075
3076 return nb_dom;
3077
3078 error:
3079 return ret;
3080 }
3081
3082 /*
3083 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3084 */
3085 static ssize_t cmd_list_channels(int domain, struct ltt_session *session,
3086 struct lttng_channel **channels)
3087 {
3088 int ret;
3089 ssize_t nb_chan = 0;
3090
3091 switch (domain) {
3092 case LTTNG_DOMAIN_KERNEL:
3093 if (session->kernel_session != NULL) {
3094 nb_chan = session->kernel_session->channel_count;
3095 }
3096 DBG3("Number of kernel channels %zd", nb_chan);
3097 break;
3098 case LTTNG_DOMAIN_UST:
3099 if (session->ust_session != NULL) {
3100 nb_chan = lttng_ht_get_count(
3101 session->ust_session->domain_global.channels);
3102 }
3103 DBG3("Number of UST global channels %zd", nb_chan);
3104 break;
3105 default:
3106 *channels = NULL;
3107 ret = -LTTCOMM_UND;
3108 goto error;
3109 }
3110
3111 if (nb_chan > 0) {
3112 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
3113 if (*channels == NULL) {
3114 ret = -LTTCOMM_FATAL;
3115 goto error;
3116 }
3117
3118 list_lttng_channels(domain, session, *channels);
3119 } else {
3120 *channels = NULL;
3121 }
3122
3123 return nb_chan;
3124
3125 error:
3126 return ret;
3127 }
3128
3129 /*
3130 * Command LTTNG_LIST_EVENTS processed by the client thread.
3131 */
3132 static ssize_t cmd_list_events(int domain, struct ltt_session *session,
3133 char *channel_name, struct lttng_event **events)
3134 {
3135 int ret = 0;
3136 ssize_t nb_event = 0;
3137
3138 switch (domain) {
3139 case LTTNG_DOMAIN_KERNEL:
3140 if (session->kernel_session != NULL) {
3141 nb_event = list_lttng_kernel_events(channel_name,
3142 session->kernel_session, events);
3143 }
3144 break;
3145 case LTTNG_DOMAIN_UST:
3146 {
3147 if (session->ust_session != NULL) {
3148 nb_event = list_lttng_ust_global_events(channel_name,
3149 &session->ust_session->domain_global, events);
3150 }
3151 break;
3152 }
3153 default:
3154 ret = -LTTCOMM_UND;
3155 goto error;
3156 }
3157
3158 ret = nb_event;
3159
3160 error:
3161 return ret;
3162 }
3163
3164 /*
3165 * Process the command requested by the lttng client within the command
3166 * context structure. This function make sure that the return structure (llm)
3167 * is set and ready for transmission before returning.
3168 *
3169 * Return any error encountered or 0 for success.
3170 */
3171 static int process_client_msg(struct command_ctx *cmd_ctx)
3172 {
3173 int ret = LTTCOMM_OK;
3174 int need_tracing_session = 1;
3175 int need_domain;
3176
3177 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
3178
3179 switch (cmd_ctx->lsm->cmd_type) {
3180 case LTTNG_CREATE_SESSION:
3181 case LTTNG_DESTROY_SESSION:
3182 case LTTNG_LIST_SESSIONS:
3183 case LTTNG_LIST_DOMAINS:
3184 case LTTNG_START_TRACE:
3185 case LTTNG_STOP_TRACE:
3186 need_domain = 0;
3187 break;
3188 default:
3189 need_domain = 1;
3190 }
3191
3192 if (opt_no_kernel && need_domain
3193 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
3194 ret = LTTCOMM_KERN_NA;
3195 goto error;
3196 }
3197
3198 /*
3199 * Check for command that don't needs to allocate a returned payload. We do
3200 * this here so we don't have to make the call for no payload at each
3201 * command.
3202 */
3203 switch(cmd_ctx->lsm->cmd_type) {
3204 case LTTNG_LIST_SESSIONS:
3205 case LTTNG_LIST_TRACEPOINTS:
3206 case LTTNG_LIST_DOMAINS:
3207 case LTTNG_LIST_CHANNELS:
3208 case LTTNG_LIST_EVENTS:
3209 break;
3210 default:
3211 /* Setup lttng message with no payload */
3212 ret = setup_lttng_msg(cmd_ctx, 0);
3213 if (ret < 0) {
3214 /* This label does not try to unlock the session */
3215 goto init_setup_error;
3216 }
3217 }
3218
3219 /* Commands that DO NOT need a session. */
3220 switch (cmd_ctx->lsm->cmd_type) {
3221 case LTTNG_CREATE_SESSION:
3222 case LTTNG_CALIBRATE:
3223 case LTTNG_LIST_SESSIONS:
3224 case LTTNG_LIST_TRACEPOINTS:
3225 need_tracing_session = 0;
3226 break;
3227 default:
3228 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
3229 session_lock_list();
3230 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
3231 session_unlock_list();
3232 if (cmd_ctx->session == NULL) {
3233 if (cmd_ctx->lsm->session.name != NULL) {
3234 ret = LTTCOMM_SESS_NOT_FOUND;
3235 } else {
3236 /* If no session name specified */
3237 ret = LTTCOMM_SELECT_SESS;
3238 }
3239 goto error;
3240 } else {
3241 /* Acquire lock for the session */
3242 session_lock(cmd_ctx->session);
3243 }
3244 break;
3245 }
3246
3247 if (!need_domain) {
3248 goto skip_domain;
3249 }
3250 /*
3251 * Check domain type for specific "pre-action".
3252 */
3253 switch (cmd_ctx->lsm->domain.type) {
3254 case LTTNG_DOMAIN_KERNEL:
3255 if (!is_root) {
3256 ret = LTTCOMM_KERN_NA;
3257 goto error;
3258 }
3259
3260 /* Kernel tracer check */
3261 if (kernel_tracer_fd == 0) {
3262 /* Basically, load kernel tracer modules */
3263 ret = init_kernel_tracer();
3264 if (ret != 0) {
3265 goto error;
3266 }
3267 }
3268
3269 /* Need a session for kernel command */
3270 if (need_tracing_session) {