Add NULL pointer check
[lttng-tools.git] / liblttngctl / lttngctl.c
CommitLineData
826d496d 1/*
82a3637f
DG
2 * liblttngctl.c
3 *
4 * Linux Trace Toolkit Control Library
5 *
826d496d 6 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
fac6795d 7 *
82a3637f
DG
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
12 *
13 * This library is distributed in the hope that it will be useful,
fac6795d 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
82a3637f
DG
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
fac6795d
DG
21 */
22
23#define _GNU_SOURCE
fac6795d 24#include <grp.h>
1e307fab 25#include <errno.h>
fac6795d
DG
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30
e88129fc 31#include <lttng-sessiond-comm.h>
1e307fab
DG
32#include <lttng-share.h>
33#include <lttng/lttng.h>
34#include <lttngerr.h>
fac6795d
DG
35
36/* Socket to session daemon for communication */
37static int sessiond_socket;
38static char sessiond_sock_path[PATH_MAX];
39
fac6795d
DG
40/* Variables */
41static char *tracing_group;
42static int connected;
43
99497cd0
MD
44/*
45 * Copy string from src to dst and enforce null terminated byte.
46 */
47static void copy_string(char *dst, const char *src, size_t len)
48{
e7d6716d 49 if (src && dst) {
99497cd0
MD
50 strncpy(dst, src, len);
51 /* Enforce the NULL terminated byte */
52 dst[len - 1] = '\0';
cd80958d
DG
53 } else if (dst) {
54 dst[0] = '\0';
99497cd0
MD
55 }
56}
57
fac6795d 58/*
cd80958d 59 * Copy domain to lttcomm_session_msg domain.
fac6795d 60 *
cd80958d
DG
61 * If domain is unknown, default domain will be the kernel.
62 */
63static void copy_lttng_domain(struct lttng_domain *dst, struct lttng_domain *src)
64{
65 if (src && dst) {
66 switch (src->type) {
67 case LTTNG_DOMAIN_KERNEL:
68 case LTTNG_DOMAIN_UST:
69 case LTTNG_DOMAIN_UST_EXEC_NAME:
70 case LTTNG_DOMAIN_UST_PID:
71 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
72 memcpy(dst, src, sizeof(struct lttng_domain));
73 break;
74 default:
75 dst->type = LTTNG_DOMAIN_KERNEL;
76 break;
77 }
78 }
79}
80
81/*
82 * Send lttcomm_session_msg to the session daemon.
fac6795d 83 *
cd80958d
DG
84 * On success, return 0
85 * On error, return error code
fac6795d 86 */
cd80958d 87static int send_session_msg(struct lttcomm_session_msg *lsm)
fac6795d
DG
88{
89 int ret;
90
91 if (!connected) {
e065084a
DG
92 ret = -ENOTCONN;
93 goto end;
fac6795d
DG
94 }
95
cd80958d
DG
96 ret = lttcomm_send_unix_sock(sessiond_socket, lsm,
97 sizeof(struct lttcomm_session_msg));
e065084a
DG
98
99end:
100 return ret;
101}
102
103/*
cd80958d 104 * Receive data from the sessiond socket.
e065084a 105 *
cd80958d
DG
106 * On success, return 0
107 * On error, return recv() error code
e065084a 108 */
ca95a216 109static int recv_data_sessiond(void *buf, size_t len)
e065084a
DG
110{
111 int ret;
112
113 if (!connected) {
114 ret = -ENOTCONN;
115 goto end;
fac6795d
DG
116 }
117
ca95a216 118 ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
fac6795d 119
e065084a 120end:
fac6795d
DG
121 return ret;
122}
123
124/*
947308c4 125 * Check if the specified group name exist.
65beb5ff 126 *
2269e89e 127 * If yes return 1, else return -1.
947308c4
DG
128 */
129static int check_tracing_group(const char *grp_name)
130{
131 struct group *grp_tracing; /* no free(). See getgrnam(3) */
132 gid_t *grp_list;
133 int grp_list_size, grp_id, i;
134 int ret = -1;
135
136 /* Get GID of group 'tracing' */
137 grp_tracing = getgrnam(grp_name);
138 if (grp_tracing == NULL) {
139 /* NULL means not found also. getgrnam(3) */
140 if (errno != 0) {
141 perror("getgrnam");
142 }
143 goto end;
144 }
145
146 /* Get number of supplementary group IDs */
147 grp_list_size = getgroups(0, NULL);
148 if (grp_list_size < 0) {
149 perror("getgroups");
150 goto end;
151 }
152
153 /* Alloc group list of the right size */
154 grp_list = malloc(grp_list_size * sizeof(gid_t));
155 grp_id = getgroups(grp_list_size, grp_list);
156 if (grp_id < -1) {
157 perror("getgroups");
158 goto free_list;
159 }
160
161 for (i = 0; i < grp_list_size; i++) {
162 if (grp_list[i] == grp_tracing->gr_gid) {
2269e89e 163 ret = 1;
947308c4
DG
164 break;
165 }
166 }
167
168free_list:
169 free(grp_list);
170
171end:
172 return ret;
173}
174
175/*
2269e89e
DG
176 * Try connect to session daemon with sock_path.
177 *
178 * Return 0 on success, else -1
179 */
180static int try_connect_sessiond(const char *sock_path)
181{
182 int ret;
183
184 /* If socket exist, we check if the daemon listens for connect. */
185 ret = access(sock_path, F_OK);
186 if (ret < 0) {
187 /* Not alive */
188 return -1;
189 }
190
191 ret = lttcomm_connect_unix_sock(sock_path);
192 if (ret < 0) {
193 /* Not alive */
194 return -1;
195 }
196
197 ret = lttcomm_close_unix_sock(ret);
198 if (ret < 0) {
199 perror("lttcomm_close_unix_sock");
200 }
201
202 return 0;
203}
204
205/*
206 * Set sessiond socket path by putting it in the global sessiond_sock_path
207 * variable.
947308c4
DG
208 */
209static int set_session_daemon_path(void)
210{
211 int ret;
2269e89e
DG
212 int in_tgroup = 0; /* In tracing group */
213 uid_t uid;
214
215 uid = getuid();
947308c4 216
2269e89e
DG
217 if (uid != 0) {
218 /* Are we in the tracing group ? */
219 in_tgroup = check_tracing_group(tracing_group);
220 }
221
222 if (uid == 0) {
223 /* Root */
224 copy_string(sessiond_sock_path,
225 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
226 sizeof(sessiond_sock_path));
227 } else if (in_tgroup) {
228 /* Tracing group */
229 copy_string(sessiond_sock_path,
230 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
231 sizeof(sessiond_sock_path));
232
233 ret = try_connect_sessiond(sessiond_sock_path);
234 if (ret < 0) {
235 /* Global session daemon not available */
236 if (snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
237 DEFAULT_HOME_CLIENT_UNIX_SOCK,
238 getenv("HOME")) < 0) {
239 return -ENOMEM;
240 }
241 }
242 } else {
243 /* Not in tracing group and not root, default */
99497cd0 244 if (snprintf(sessiond_sock_path, PATH_MAX,
cd80958d
DG
245 DEFAULT_HOME_CLIENT_UNIX_SOCK,
246 getenv("HOME")) < 0) {
947308c4
DG
247 return -ENOMEM;
248 }
947308c4
DG
249 }
250
251 return 0;
252}
253
65beb5ff
DG
254/*
255 * Connect to the LTTng session daemon.
256 *
257 * On success, return 0. On error, return -1.
258 */
259static int connect_sessiond(void)
260{
261 int ret;
262
263 ret = set_session_daemon_path();
264 if (ret < 0) {
265 return ret;
266 }
267
268 /* Connect to the sesssion daemon */
269 ret = lttcomm_connect_unix_sock(sessiond_sock_path);
270 if (ret < 0) {
271 return ret;
272 }
273
274 sessiond_socket = ret;
275 connected = 1;
276
277 return 0;
278}
279
280/*
281 * Clean disconnect the session daemon.
282 */
283static int disconnect_sessiond(void)
284{
285 int ret = 0;
286
287 if (connected) {
288 ret = lttcomm_close_unix_sock(sessiond_socket);
289 sessiond_socket = 0;
290 connected = 0;
291 }
292
293 return ret;
294}
295
35a6fdb7 296/*
cd80958d 297 * Ask the session daemon a specific command and put the data into buf.
65beb5ff 298 *
cd80958d 299 * Return size of data (only payload, not header).
65beb5ff 300 */
cd80958d 301static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
65beb5ff
DG
302{
303 int ret;
304 size_t size;
305 void *data = NULL;
cd80958d 306 struct lttcomm_lttng_msg llm;
65beb5ff
DG
307
308 ret = connect_sessiond();
309 if (ret < 0) {
310 goto end;
311 }
312
65beb5ff 313 /* Send command to session daemon */
cd80958d 314 ret = send_session_msg(lsm);
65beb5ff
DG
315 if (ret < 0) {
316 goto end;
317 }
318
319 /* Get header from data transmission */
320 ret = recv_data_sessiond(&llm, sizeof(llm));
321 if (ret < 0) {
322 goto end;
323 }
324
325 /* Check error code if OK */
326 if (llm.ret_code != LTTCOMM_OK) {
327 ret = -llm.ret_code;
328 goto end;
329 }
330
331 size = llm.data_size;
332 if (size == 0) {
7d29a247 333 ret = 0;
65beb5ff
DG
334 goto end;
335 }
336
337 data = (void*) malloc(size);
338
339 /* Get payload data */
340 ret = recv_data_sessiond(data, size);
341 if (ret < 0) {
342 free(data);
343 goto end;
344 }
345
83009e5e
DG
346 /*
347 * Extra protection not to dereference a NULL pointer. If buf is NULL at
348 * this point, an error is returned and data is freed.
349 */
350 if (buf == NULL) {
351 ret = -1;
352 free(data);
353 goto end;
354 }
355
65beb5ff
DG
356 *buf = data;
357 ret = size;
358
359end:
360 disconnect_sessiond();
361 return ret;
362}
363
9f19cc17 364/*
cd80958d 365 * Create lttng handle and return pointer.
9f19cc17 366 */
cd80958d
DG
367struct lttng_handle *lttng_create_handle(const char *session_name,
368 struct lttng_domain *domain)
9f19cc17 369{
cd80958d
DG
370 struct lttng_handle *handle;
371
372 handle = malloc(sizeof(struct lttng_handle));
373 if (handle == NULL) {
374 perror("malloc handle");
375 goto end;
376 }
377
378 /* Copy session name */
379 copy_string(handle->session_name, session_name,
380 sizeof(handle->session_name));
381
382 /* Copy lttng domain */
383 copy_lttng_domain(&handle->domain, domain);
384
385end:
386 return handle;
387}
388
389/*
390 * Destroy handle by free(3) the pointer.
391 */
392void lttng_destroy_handle(struct lttng_handle *handle)
393{
394 if (handle) {
395 free(handle);
eb354453
DG
396 }
397}
398
d9800920
DG
399/*
400 * Register an outside consumer.
401 */
402int lttng_register_consumer(struct lttng_handle *handle,
403 const char *socket_path)
404{
405 struct lttcomm_session_msg lsm;
406
407 lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
408 copy_string(lsm.session.name, handle->session_name,
409 sizeof(lsm.session.name));
410 copy_lttng_domain(&lsm.domain, &handle->domain);
411
412 copy_string(lsm.u.reg.path, socket_path, sizeof(lsm.u.reg.path));
413
414 return ask_sessiond(&lsm, NULL);
415}
416
1df4dedd 417/*
f3ed775e 418 * Start tracing for all trace of the session.
1df4dedd 419 */
cd80958d 420int lttng_start_tracing(struct lttng_handle *handle)
f3ed775e 421{
cd80958d
DG
422 struct lttcomm_session_msg lsm;
423
424 if (!handle) {
425 return -1;
426 }
427
428 lsm.cmd_type = LTTNG_START_TRACE;
429 copy_string(lsm.session.name, handle->session_name,
430 sizeof(lsm.session.name));
431
432 return ask_sessiond(&lsm, NULL);
f3ed775e 433}
1df4dedd
DG
434
435/*
f3ed775e
DG
436 * Stop tracing for all trace of the session.
437 */
cd80958d 438int lttng_stop_tracing(struct lttng_handle *handle)
f3ed775e 439{
cd80958d
DG
440 struct lttcomm_session_msg lsm;
441
442 lsm.cmd_type = LTTNG_STOP_TRACE;
443 copy_string(lsm.session.name, handle->session_name,
444 sizeof(lsm.session.name));
445
446 return ask_sessiond(&lsm, NULL);
f3ed775e
DG
447}
448
449/*
cd80958d 450 * Add context to event or/and channel.
1df4dedd 451 */
cd80958d 452int lttng_add_context(struct lttng_handle *handle,
38057ed1
DG
453 struct lttng_event_context *ctx, const char *event_name,
454 const char *channel_name)
d65106b1 455{
cd80958d
DG
456 struct lttcomm_session_msg lsm;
457
458 if (!handle) {
459 return -1;
460 }
461
462 lsm.cmd_type = LTTNG_ADD_CONTEXT;
463
464 /* Copy channel name */
465 copy_string(lsm.u.context.channel_name, channel_name,
466 sizeof(lsm.u.context.channel_name));
467 /* Copy event name */
468 copy_string(lsm.u.context.event_name, event_name,
469 sizeof(lsm.u.context.event_name));
470
471 copy_lttng_domain(&lsm.domain, &handle->domain);
d65106b1 472
eb354453
DG
473 if (ctx) {
474 memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
d65106b1
DG
475 }
476
cd80958d
DG
477 copy_string(lsm.session.name, handle->session_name,
478 sizeof(lsm.session.name));
479
480 return ask_sessiond(&lsm, NULL);
d65106b1
DG
481}
482
f3ed775e 483/*
cd80958d 484 * Enable event
f3ed775e 485 */
cd80958d 486int lttng_enable_event(struct lttng_handle *handle,
38057ed1 487 struct lttng_event *ev, const char *channel_name)
1df4dedd 488{
cd80958d
DG
489 struct lttcomm_session_msg lsm;
490
491 if (!handle) {
492 return -1;
493 }
33a2b854 494
94cf3c47 495 if (channel_name == NULL) {
cd80958d
DG
496 copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
497 sizeof(lsm.u.enable.channel_name));
33a2b854 498 } else {
cd80958d
DG
499 copy_string(lsm.u.enable.channel_name, channel_name,
500 sizeof(lsm.u.enable.channel_name));
eb354453
DG
501 }
502
cd80958d 503 copy_lttng_domain(&lsm.domain, &handle->domain);
0d0c377a 504
cd80958d
DG
505 if (ev) {
506 lsm.cmd_type = LTTNG_ENABLE_EVENT;
507 memcpy(&lsm.u.enable.event, ev, sizeof(lsm.u.enable.event));
0d0c377a 508 } else {
cd80958d 509 lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
f3ed775e
DG
510 }
511
cd80958d
DG
512 copy_string(lsm.session.name, handle->session_name,
513 sizeof(lsm.session.name));
514
515 return ask_sessiond(&lsm, NULL);
1df4dedd
DG
516}
517
518/*
f5177a38 519 * Disable event of a channel and domain.
1df4dedd 520 */
cd80958d 521int lttng_disable_event(struct lttng_handle *handle, const char *name,
38057ed1 522 const char *channel_name)
1df4dedd 523{
cd80958d 524 struct lttcomm_session_msg lsm;
1df4dedd 525
cd80958d
DG
526 if (!handle) {
527 return -1;
528 }
529
530 if (channel_name) {
531 copy_string(lsm.u.disable.channel_name, channel_name,
532 sizeof(lsm.u.disable.channel_name));
f3ed775e 533 } else {
cd80958d
DG
534 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
535 sizeof(lsm.u.disable.channel_name));
eb354453
DG
536 }
537
cd80958d 538 copy_lttng_domain(&lsm.domain, &handle->domain);
f5177a38
DG
539
540 if (name == NULL) {
cd80958d
DG
541 copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
542 lsm.cmd_type = LTTNG_DISABLE_EVENT;
f5177a38 543 } else {
cd80958d 544 lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
f3ed775e
DG
545 }
546
cd80958d
DG
547 copy_string(lsm.session.name, handle->session_name,
548 sizeof(lsm.session.name));
549
550 return ask_sessiond(&lsm, NULL);
1df4dedd
DG
551}
552
553/*
0d0c377a 554 * Enable channel per domain
a5c5a2bd 555 */
cd80958d 556int lttng_enable_channel(struct lttng_handle *handle,
38057ed1 557 struct lttng_channel *chan)
a5c5a2bd 558{
cd80958d
DG
559 struct lttcomm_session_msg lsm;
560
561 if (!handle) {
562 return -1;
563 }
564
eb354453 565 if (chan) {
cd80958d 566 memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
eb354453 567 }
7d29a247 568
cd80958d
DG
569 lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
570
571 copy_lttng_domain(&lsm.domain, &handle->domain);
7d29a247 572
cd80958d
DG
573 copy_string(lsm.session.name, handle->session_name,
574 sizeof(lsm.session.name));
575
576 return ask_sessiond(&lsm, NULL);
8c0faa1d 577}
1df4dedd 578
2ef84c95 579/*
0b97ec54 580 * All tracing will be stopped for registered events of the channel.
2ef84c95 581 */
cd80958d 582int lttng_disable_channel(struct lttng_handle *handle, const char *name)
2ef84c95 583{
cd80958d
DG
584 struct lttcomm_session_msg lsm;
585
586 if (!handle) {
587 return -1;
588 }
589
590 if (name) {
591 copy_string(lsm.u.disable.channel_name, name,
592 sizeof(lsm.u.disable.channel_name));
593 }
594
595 lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
1df4dedd 596
cd80958d
DG
597 copy_lttng_domain(&lsm.domain, &handle->domain);
598
599 copy_string(lsm.session.name, handle->session_name,
600 sizeof(lsm.session.name));
601
602 return ask_sessiond(&lsm, NULL);
ca95a216
DG
603}
604
fac6795d 605/*
2a71efd5 606 * List all available tracepoints of domain.
fac6795d 607 *
2a71efd5 608 * Return the size (bytes) of the list and set the events array.
7d29a247 609 * On error, return negative value.
fac6795d 610 */
cd80958d 611int lttng_list_tracepoints(struct lttng_handle *handle,
2a71efd5 612 struct lttng_event **events)
fac6795d 613{
052da939 614 int ret;
cd80958d
DG
615 struct lttcomm_session_msg lsm;
616
617 if (!handle) {
618 return -1;
619 }
fac6795d 620
cd80958d
DG
621 lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
622 copy_lttng_domain(&lsm.domain, &handle->domain);
2a71efd5 623
cd80958d 624 ret = ask_sessiond(&lsm, (void **) events);
052da939
DG
625 if (ret < 0) {
626 return ret;
eb354453 627 }
fac6795d 628
9f19cc17 629 return ret / sizeof(struct lttng_event);
fac6795d
DG
630}
631
1657e9bb 632/*
7d29a247 633 * Return a human readable string of code
1657e9bb 634 */
7d29a247 635const char *lttng_get_readable_code(int code)
1657e9bb 636{
7d29a247
DG
637 if (code > -LTTCOMM_OK) {
638 return "Ended with errors";
1657e9bb
DG
639 }
640
7d29a247 641 return lttcomm_get_readable_code(code);
1657e9bb
DG
642}
643
aaf97519 644/*
894be886 645 * Create a brand new session using name.
aaf97519 646 */
38057ed1 647int lttng_create_session(const char *name, const char *path)
aaf97519 648{
cd80958d
DG
649 struct lttcomm_session_msg lsm;
650
651 lsm.cmd_type = LTTNG_CREATE_SESSION;
652 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
653 copy_string(lsm.session.path, path, sizeof(lsm.session.path));
654
655 return ask_sessiond(&lsm, NULL);
8028d920
DG
656}
657
658/*
8028d920
DG
659 * Destroy session using name.
660 */
cd80958d 661int lttng_destroy_session(struct lttng_handle *handle)
8028d920 662{
cd80958d
DG
663 struct lttcomm_session_msg lsm;
664
665 if (!handle) {
666 return -1;
667 }
668
669 lsm.cmd_type = LTTNG_DESTROY_SESSION;
670 copy_string(lsm.session.name, handle->session_name,
671 sizeof(lsm.session.name));
672
673 return ask_sessiond(&lsm, NULL);
aaf97519
DG
674}
675
57167058 676/*
57167058
DG
677 * Ask the session daemon for all available sessions.
678 *
ca95a216
DG
679 * Return number of session.
680 * On error, return negative value.
57167058 681 */
ca95a216 682int lttng_list_sessions(struct lttng_session **sessions)
57167058 683{
ca95a216 684 int ret;
cd80958d 685 struct lttcomm_session_msg lsm;
57167058 686
cd80958d
DG
687 lsm.cmd_type = LTTNG_LIST_SESSIONS;
688 ret = ask_sessiond(&lsm, (void**) sessions);
57167058 689 if (ret < 0) {
ca95a216 690 return ret;
57167058
DG
691 }
692
ca95a216 693 return ret / sizeof(struct lttng_session);
57167058
DG
694}
695
9f19cc17
DG
696/*
697 * List domain of a session.
698 */
cd80958d
DG
699int lttng_list_domains(struct lttng_handle *handle,
700 struct lttng_domain **domains)
9f19cc17
DG
701{
702 int ret;
cd80958d
DG
703 struct lttcomm_session_msg lsm;
704
705 if (!handle) {
706 return -1;
707 }
9f19cc17 708
cd80958d
DG
709 lsm.cmd_type = LTTNG_LIST_DOMAINS;
710
711 copy_string(lsm.session.name, handle->session_name,
712 sizeof(lsm.session.name));
713
714 ret = ask_sessiond(&lsm, (void**) domains);
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715 if (ret < 0) {
716 return ret;
717 }
718
719 return ret / sizeof(struct lttng_domain);
720}
721
722/*
723 * List channels of a session
724 */
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725int lttng_list_channels(struct lttng_handle *handle,
726 struct lttng_channel **channels)
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727{
728 int ret;
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729 struct lttcomm_session_msg lsm;
730
731 if (!handle) {
732 return -1;
733 }
734
735 lsm.cmd_type = LTTNG_LIST_CHANNELS;
736 copy_string(lsm.session.name, handle->session_name,
737 sizeof(lsm.session.name));
9f19cc17 738
cd80958d 739 copy_lttng_domain(&lsm.domain, &handle->domain);
9f19cc17 740
cd80958d 741 ret = ask_sessiond(&lsm, (void**) channels);
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742 if (ret < 0) {
743 return ret;
744 }
745
746 return ret / sizeof(struct lttng_channel);
747}
748
749/*
750 * List events of a session channel.
751 */
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752int lttng_list_events(struct lttng_handle *handle,
753 const char *channel_name, struct lttng_event **events)
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754{
755 int ret;
cd80958d 756 struct lttcomm_session_msg lsm;
9f19cc17 757
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758 if (!handle) {
759 return -1;
760 }
761
762 lsm.cmd_type = LTTNG_LIST_EVENTS;
763 copy_string(lsm.session.name, handle->session_name,
764 sizeof(lsm.session.name));
765 copy_string(lsm.u.list.channel_name, channel_name,
766 sizeof(lsm.u.list.channel_name));
767
768 copy_lttng_domain(&lsm.domain, &handle->domain);
9f19cc17 769
cd80958d 770 ret = ask_sessiond(&lsm, (void**) events);
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771 if (ret < 0) {
772 return ret;
773 }
774
775 return ret / sizeof(struct lttng_event);
776}
777
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778/*
779 * lttng_set_tracing_group
780 *
781 * Set tracing group variable with name. This function
782 * allocate memory pointed by tracing_group.
783 */
784int lttng_set_tracing_group(const char *name)
785{
786 if (asprintf(&tracing_group, "%s", name) < 0) {
787 return -ENOMEM;
788 }
789
790 return 0;
791}
792
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793/*
794 * lttng_calibrate
795 */
cd80958d 796int lttng_calibrate(struct lttng_handle *handle,
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797 struct lttng_calibrate *calibrate)
798{
cd80958d 799 struct lttcomm_session_msg lsm;
d0254c7c 800
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801 if (!handle) {
802 return -1;
803 }
d0254c7c 804
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805 lsm.cmd_type = LTTNG_CALIBRATE;
806 copy_lttng_domain(&lsm.domain, &handle->domain);
d0254c7c 807
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808 memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
809
810 return ask_sessiond(&lsm, NULL);
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811}
812
fac6795d 813/*
2269e89e 814 * Check if session daemon is alive.
fac6795d 815 *
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816 * Return 1 if alive or 0 if not.
817 * On error return -1
fac6795d 818 */
947308c4 819int lttng_session_daemon_alive(void)
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820{
821 int ret;
822
823 ret = set_session_daemon_path();
824 if (ret < 0) {
947308c4 825 /* Error */
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826 return ret;
827 }
828
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829 if (strlen(sessiond_sock_path) == 0) {
830 /* No socket path set. Weird error */
831 return -1;
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832 }
833
2269e89e 834 ret = try_connect_sessiond(sessiond_sock_path);
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835 if (ret < 0) {
836 /* Not alive */
837 return 0;
838 }
7d8234d9 839
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840 /* Is alive */
841 return 1;
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842}
843
844/*
845 * lib constructor
846 */
847static void __attribute__((constructor)) init()
848{
849 /* Set default session group */
64a23ac4 850 lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
fac6795d 851}
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