Commit | Line | Data |
---|---|---|
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 | |
24 | #include <errno.h> | |
25 | #include <grp.h> | |
26 | #include <stdio.h> | |
27 | #include <stdlib.h> | |
28 | #include <string.h> | |
29 | #include <unistd.h> | |
30 | ||
5b97ec60 | 31 | #include <lttng/lttng.h> |
fac6795d DG |
32 | |
33 | #include "liblttsessiondcomm.h" | |
34 | #include "lttngerr.h" | |
f3ed775e | 35 | #include "lttng-share.h" |
fac6795d DG |
36 | |
37 | /* Socket to session daemon for communication */ | |
38 | static int sessiond_socket; | |
39 | static char sessiond_sock_path[PATH_MAX]; | |
40 | ||
41 | /* Communication structure to ltt-sessiond */ | |
fac6795d | 42 | static struct lttcomm_session_msg lsm; |
5461b305 | 43 | static struct lttcomm_lttng_msg llm; |
fac6795d | 44 | |
fac6795d DG |
45 | /* Variables */ |
46 | static char *tracing_group; | |
47 | static int connected; | |
48 | ||
49 | /* | |
ca95a216 | 50 | * send_data_sessiond |
fac6795d | 51 | * |
e065084a | 52 | * Send lttcomm_session_msg to the session daemon. |
fac6795d DG |
53 | * |
54 | * On success, return 0 | |
55 | * On error, return error code | |
56 | */ | |
ca95a216 | 57 | static int send_data_sessiond(void) |
fac6795d DG |
58 | { |
59 | int ret; | |
60 | ||
61 | if (!connected) { | |
e065084a DG |
62 | ret = -ENOTCONN; |
63 | goto end; | |
fac6795d DG |
64 | } |
65 | ||
66 | ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm)); | |
e065084a DG |
67 | |
68 | end: | |
69 | return ret; | |
70 | } | |
71 | ||
72 | /* | |
ca95a216 | 73 | * recv_data_sessiond |
e065084a DG |
74 | * |
75 | * Receive data from the sessiond socket. | |
76 | * | |
77 | * On success, return 0 | |
78 | * On error, return recv() error code | |
79 | */ | |
ca95a216 | 80 | static int recv_data_sessiond(void *buf, size_t len) |
e065084a DG |
81 | { |
82 | int ret; | |
83 | ||
84 | if (!connected) { | |
85 | ret = -ENOTCONN; | |
86 | goto end; | |
fac6795d DG |
87 | } |
88 | ||
ca95a216 | 89 | ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len); |
fac6795d | 90 | |
e065084a | 91 | end: |
fac6795d DG |
92 | return ret; |
93 | } | |
94 | ||
95 | /* | |
947308c4 | 96 | * Check if the specified group name exist. |
65beb5ff DG |
97 | * |
98 | * If yes return 0, else return -1. | |
947308c4 DG |
99 | */ |
100 | static int check_tracing_group(const char *grp_name) | |
101 | { | |
102 | struct group *grp_tracing; /* no free(). See getgrnam(3) */ | |
103 | gid_t *grp_list; | |
104 | int grp_list_size, grp_id, i; | |
105 | int ret = -1; | |
106 | ||
107 | /* Get GID of group 'tracing' */ | |
108 | grp_tracing = getgrnam(grp_name); | |
109 | if (grp_tracing == NULL) { | |
110 | /* NULL means not found also. getgrnam(3) */ | |
111 | if (errno != 0) { | |
112 | perror("getgrnam"); | |
113 | } | |
114 | goto end; | |
115 | } | |
116 | ||
117 | /* Get number of supplementary group IDs */ | |
118 | grp_list_size = getgroups(0, NULL); | |
119 | if (grp_list_size < 0) { | |
120 | perror("getgroups"); | |
121 | goto end; | |
122 | } | |
123 | ||
124 | /* Alloc group list of the right size */ | |
125 | grp_list = malloc(grp_list_size * sizeof(gid_t)); | |
126 | grp_id = getgroups(grp_list_size, grp_list); | |
127 | if (grp_id < -1) { | |
128 | perror("getgroups"); | |
129 | goto free_list; | |
130 | } | |
131 | ||
132 | for (i = 0; i < grp_list_size; i++) { | |
133 | if (grp_list[i] == grp_tracing->gr_gid) { | |
134 | ret = 0; | |
135 | break; | |
136 | } | |
137 | } | |
138 | ||
139 | free_list: | |
140 | free(grp_list); | |
141 | ||
142 | end: | |
143 | return ret; | |
144 | } | |
145 | ||
146 | /* | |
65beb5ff DG |
147 | * Set sessiond socket path by putting it in the global sessiond_sock_path |
148 | * variable. | |
947308c4 DG |
149 | */ |
150 | static int set_session_daemon_path(void) | |
151 | { | |
152 | int ret; | |
153 | ||
154 | /* Are we in the tracing group ? */ | |
155 | ret = check_tracing_group(tracing_group); | |
156 | if (ret < 0 && getuid() != 0) { | |
157 | if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK, | |
158 | getenv("HOME")) < 0) { | |
159 | return -ENOMEM; | |
160 | } | |
161 | } else { | |
162 | strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK, | |
163 | sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK)); | |
164 | } | |
165 | ||
166 | return 0; | |
167 | } | |
168 | ||
65beb5ff DG |
169 | /* |
170 | * Connect to the LTTng session daemon. | |
171 | * | |
172 | * On success, return 0. On error, return -1. | |
173 | */ | |
174 | static int connect_sessiond(void) | |
175 | { | |
176 | int ret; | |
177 | ||
178 | ret = set_session_daemon_path(); | |
179 | if (ret < 0) { | |
180 | return ret; | |
181 | } | |
182 | ||
183 | /* Connect to the sesssion daemon */ | |
184 | ret = lttcomm_connect_unix_sock(sessiond_sock_path); | |
185 | if (ret < 0) { | |
186 | return ret; | |
187 | } | |
188 | ||
189 | sessiond_socket = ret; | |
190 | connected = 1; | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* | |
196 | * Clean disconnect the session daemon. | |
197 | */ | |
198 | static int disconnect_sessiond(void) | |
199 | { | |
200 | int ret = 0; | |
201 | ||
202 | if (connected) { | |
203 | ret = lttcomm_close_unix_sock(sessiond_socket); | |
204 | sessiond_socket = 0; | |
205 | connected = 0; | |
206 | } | |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
35a6fdb7 DG |
211 | /* |
212 | * Reset the session message structure. | |
213 | */ | |
214 | static void reset_session_msg(void) | |
215 | { | |
216 | memset(&lsm, 0, sizeof(struct lttcomm_session_msg)); | |
217 | } | |
218 | ||
65beb5ff DG |
219 | /* |
220 | * ask_sessiond | |
221 | * | |
222 | * Ask the session daemon a specific command and put the data into buf. | |
223 | * | |
224 | * Return size of data (only payload, not header). | |
225 | */ | |
226 | static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf) | |
227 | { | |
228 | int ret; | |
229 | size_t size; | |
230 | void *data = NULL; | |
231 | ||
232 | ret = connect_sessiond(); | |
233 | if (ret < 0) { | |
234 | goto end; | |
235 | } | |
236 | ||
237 | lsm.cmd_type = lct; | |
238 | ||
239 | /* Send command to session daemon */ | |
240 | ret = send_data_sessiond(); | |
241 | if (ret < 0) { | |
242 | goto end; | |
243 | } | |
244 | ||
245 | /* Get header from data transmission */ | |
246 | ret = recv_data_sessiond(&llm, sizeof(llm)); | |
247 | if (ret < 0) { | |
248 | goto end; | |
249 | } | |
250 | ||
251 | /* Check error code if OK */ | |
252 | if (llm.ret_code != LTTCOMM_OK) { | |
253 | ret = -llm.ret_code; | |
254 | goto end; | |
255 | } | |
256 | ||
257 | size = llm.data_size; | |
258 | if (size == 0) { | |
7d29a247 | 259 | ret = 0; |
65beb5ff DG |
260 | goto end; |
261 | } | |
262 | ||
263 | data = (void*) malloc(size); | |
264 | ||
265 | /* Get payload data */ | |
266 | ret = recv_data_sessiond(data, size); | |
267 | if (ret < 0) { | |
268 | free(data); | |
269 | goto end; | |
270 | } | |
271 | ||
272 | *buf = data; | |
273 | ret = size; | |
274 | ||
275 | end: | |
276 | disconnect_sessiond(); | |
35a6fdb7 | 277 | reset_session_msg(); |
65beb5ff DG |
278 | return ret; |
279 | } | |
280 | ||
9f19cc17 | 281 | /* |
eb354453 DG |
282 | * Copy domain to lttcomm_session_msg domain. If unknown domain, default domain |
283 | * will be the kernel. | |
9f19cc17 | 284 | */ |
eb354453 | 285 | static void copy_lttng_domain(struct lttng_domain *dom) |
9f19cc17 | 286 | { |
eb354453 DG |
287 | if (dom) { |
288 | switch (dom->type) { | |
289 | case LTTNG_DOMAIN_KERNEL: | |
290 | case LTTNG_DOMAIN_UST: | |
291 | case LTTNG_DOMAIN_UST_EXEC_NAME: | |
292 | case LTTNG_DOMAIN_UST_PID: | |
293 | case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN: | |
294 | memcpy(&lsm.domain, dom, sizeof(struct lttng_domain)); | |
295 | break; | |
296 | default: | |
297 | lsm.domain.type = LTTNG_DOMAIN_KERNEL; | |
298 | break; | |
299 | } | |
300 | } | |
301 | } | |
302 | ||
303 | /* | |
304 | * Copy string from src to dst and enforce null terminated byte. | |
305 | */ | |
306 | static void copy_string(char *dst, const char *src, size_t len) | |
307 | { | |
308 | if (src && dst) { | |
309 | strncpy(dst, src, len); | |
310 | /* Enforce the NULL terminated byte */ | |
311 | dst[len - 1] = '\0'; | |
9f19cc17 DG |
312 | } |
313 | } | |
314 | ||
1df4dedd | 315 | /* |
f3ed775e | 316 | * Start tracing for all trace of the session. |
1df4dedd | 317 | */ |
38057ed1 | 318 | int lttng_start_tracing(const char *session_name) |
f3ed775e | 319 | { |
42abccdb | 320 | copy_string(lsm.session.name, session_name, NAME_MAX); |
f3ed775e DG |
321 | return ask_sessiond(LTTNG_START_TRACE, NULL); |
322 | } | |
1df4dedd DG |
323 | |
324 | /* | |
f3ed775e DG |
325 | * Stop tracing for all trace of the session. |
326 | */ | |
38057ed1 | 327 | int lttng_stop_tracing(const char *session_name) |
f3ed775e | 328 | { |
42abccdb | 329 | copy_string(lsm.session.name, session_name, NAME_MAX); |
f3ed775e DG |
330 | return ask_sessiond(LTTNG_STOP_TRACE, NULL); |
331 | } | |
332 | ||
333 | /* | |
7d29a247 | 334 | * lttng_add_context |
1df4dedd | 335 | */ |
7d29a247 | 336 | int lttng_add_context(struct lttng_domain *domain, |
38057ed1 DG |
337 | struct lttng_event_context *ctx, const char *event_name, |
338 | const char *channel_name) | |
d65106b1 | 339 | { |
eb354453 DG |
340 | copy_string(lsm.u.context.channel_name, channel_name, NAME_MAX); |
341 | copy_string(lsm.u.context.event_name, event_name, NAME_MAX); | |
b579acd9 | 342 | copy_lttng_domain(domain); |
d65106b1 | 343 | |
eb354453 DG |
344 | if (ctx) { |
345 | memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context)); | |
d65106b1 DG |
346 | } |
347 | ||
b579acd9 | 348 | return ask_sessiond(LTTNG_ADD_CONTEXT, NULL); |
d65106b1 DG |
349 | } |
350 | ||
f3ed775e | 351 | /* |
7d29a247 | 352 | * lttng_enable_event |
f3ed775e | 353 | */ |
7d29a247 | 354 | int lttng_enable_event(struct lttng_domain *domain, |
38057ed1 | 355 | struct lttng_event *ev, const char *channel_name) |
1df4dedd | 356 | { |
eb354453 | 357 | int ret = -1; |
33a2b854 | 358 | |
94cf3c47 | 359 | if (channel_name == NULL) { |
eb354453 | 360 | copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
33a2b854 | 361 | } else { |
eb354453 DG |
362 | copy_string(lsm.u.enable.channel_name, channel_name, NAME_MAX); |
363 | } | |
364 | ||
365 | if (domain) { | |
366 | switch (domain->type) { | |
367 | case LTTNG_DOMAIN_KERNEL: | |
368 | if (ev == NULL) { | |
369 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL); | |
370 | } else { | |
371 | memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event)); | |
372 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL); | |
373 | } | |
374 | break; | |
375 | case LTTNG_DOMAIN_UST: | |
376 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
377 | break; | |
378 | default: | |
379 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
380 | break; | |
381 | }; | |
f3ed775e DG |
382 | } |
383 | ||
33a2b854 | 384 | return ret; |
1df4dedd DG |
385 | } |
386 | ||
387 | /* | |
f5177a38 | 388 | * Disable event of a channel and domain. |
1df4dedd | 389 | */ |
38057ed1 DG |
390 | int lttng_disable_event(struct lttng_domain *domain, const char *name, |
391 | const char *channel_name) | |
1df4dedd | 392 | { |
eb354453 | 393 | int ret = -1; |
1df4dedd | 394 | |
94cf3c47 | 395 | if (channel_name == NULL) { |
eb354453 | 396 | copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
f3ed775e | 397 | } else { |
eb354453 DG |
398 | copy_string(lsm.u.disable.channel_name, channel_name, NAME_MAX); |
399 | } | |
400 | ||
f5177a38 DG |
401 | copy_lttng_domain(domain); |
402 | ||
403 | if (name == NULL) { | |
404 | ret = ask_sessiond(LTTNG_DISABLE_ALL_EVENT, NULL); | |
405 | } else { | |
406 | copy_string(lsm.u.disable.name, name, NAME_MAX); | |
407 | ret = ask_sessiond(LTTNG_DISABLE_EVENT, NULL); | |
f3ed775e DG |
408 | } |
409 | ||
f3ed775e | 410 | return ret; |
1df4dedd DG |
411 | } |
412 | ||
413 | /* | |
7d29a247 | 414 | * Enable recording for a channel for the kernel tracer. |
a5c5a2bd | 415 | */ |
38057ed1 DG |
416 | int lttng_enable_channel(struct lttng_domain *domain, |
417 | struct lttng_channel *chan) | |
a5c5a2bd | 418 | { |
eb354453 | 419 | int ret = -1; |
8c0faa1d | 420 | |
eb354453 DG |
421 | if (chan) { |
422 | memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel)); | |
423 | } | |
7d29a247 | 424 | |
eb354453 DG |
425 | if (domain) { |
426 | switch (domain->type) { | |
427 | case LTTNG_DOMAIN_KERNEL: | |
428 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL); | |
429 | break; | |
430 | case LTTNG_DOMAIN_UST: | |
431 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
432 | break; | |
433 | default: | |
434 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
435 | break; | |
436 | }; | |
437 | } | |
7d29a247 DG |
438 | |
439 | return ret; | |
8c0faa1d | 440 | } |
1df4dedd | 441 | |
2ef84c95 | 442 | /* |
0b97ec54 DG |
443 | * Disable channel. |
444 | * | |
445 | * All tracing will be stopped for registered events of the channel. | |
2ef84c95 | 446 | */ |
38057ed1 | 447 | int lttng_disable_channel(struct lttng_domain *domain, const char *name) |
2ef84c95 | 448 | { |
eb354453 | 449 | copy_string(lsm.u.disable.channel_name, name, NAME_MAX); |
0b97ec54 | 450 | copy_lttng_domain(domain); |
1df4dedd | 451 | |
0b97ec54 | 452 | return ask_sessiond(LTTNG_DISABLE_CHANNEL, NULL); |
ca95a216 DG |
453 | } |
454 | ||
fac6795d | 455 | /* |
2a71efd5 | 456 | * List all available tracepoints of domain. |
fac6795d | 457 | * |
2a71efd5 | 458 | * Return the size (bytes) of the list and set the events array. |
7d29a247 | 459 | * On error, return negative value. |
fac6795d | 460 | */ |
2a71efd5 DG |
461 | int lttng_list_tracepoints(struct lttng_domain *domain, |
462 | struct lttng_event **events) | |
fac6795d | 463 | { |
052da939 | 464 | int ret; |
fac6795d | 465 | |
eb354453 | 466 | copy_lttng_domain(domain); |
2a71efd5 | 467 | |
052da939 DG |
468 | ret = ask_sessiond(LTTNG_LIST_TRACEPOINTS, (void **) events); |
469 | if (ret < 0) { | |
470 | return ret; | |
eb354453 | 471 | } |
fac6795d | 472 | |
9f19cc17 | 473 | return ret / sizeof(struct lttng_event); |
fac6795d DG |
474 | } |
475 | ||
1657e9bb | 476 | /* |
7d29a247 | 477 | * Return a human readable string of code |
1657e9bb | 478 | */ |
7d29a247 | 479 | const char *lttng_get_readable_code(int code) |
1657e9bb | 480 | { |
7d29a247 DG |
481 | if (code > -LTTCOMM_OK) { |
482 | return "Ended with errors"; | |
1657e9bb DG |
483 | } |
484 | ||
7d29a247 | 485 | return lttcomm_get_readable_code(code); |
1657e9bb DG |
486 | } |
487 | ||
aaf97519 | 488 | /* |
894be886 | 489 | * Create a brand new session using name. |
aaf97519 | 490 | */ |
38057ed1 | 491 | int lttng_create_session(const char *name, const char *path) |
aaf97519 | 492 | { |
42abccdb DG |
493 | copy_string(lsm.session.name, name, NAME_MAX); |
494 | copy_string(lsm.session.path, path, PATH_MAX); | |
947308c4 | 495 | return ask_sessiond(LTTNG_CREATE_SESSION, NULL); |
8028d920 DG |
496 | } |
497 | ||
498 | /* | |
8028d920 DG |
499 | * Destroy session using name. |
500 | */ | |
38057ed1 | 501 | int lttng_destroy_session(const char *name) |
8028d920 | 502 | { |
42abccdb | 503 | copy_string(lsm.session.name, name, NAME_MAX); |
947308c4 | 504 | return ask_sessiond(LTTNG_DESTROY_SESSION, NULL); |
aaf97519 DG |
505 | } |
506 | ||
57167058 | 507 | /* |
57167058 DG |
508 | * Ask the session daemon for all available sessions. |
509 | * | |
ca95a216 DG |
510 | * Return number of session. |
511 | * On error, return negative value. | |
57167058 | 512 | */ |
ca95a216 | 513 | int lttng_list_sessions(struct lttng_session **sessions) |
57167058 | 514 | { |
ca95a216 | 515 | int ret; |
57167058 | 516 | |
ca95a216 | 517 | ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions); |
57167058 | 518 | if (ret < 0) { |
ca95a216 | 519 | return ret; |
57167058 DG |
520 | } |
521 | ||
ca95a216 | 522 | return ret / sizeof(struct lttng_session); |
57167058 DG |
523 | } |
524 | ||
9f19cc17 DG |
525 | /* |
526 | * List domain of a session. | |
527 | */ | |
528 | int lttng_list_domains(const char *session_name, struct lttng_domain **domains) | |
529 | { | |
530 | int ret; | |
531 | ||
42abccdb | 532 | copy_string(lsm.session.name, session_name, NAME_MAX); |
9f19cc17 DG |
533 | ret = ask_sessiond(LTTNG_LIST_DOMAINS, (void**) domains); |
534 | if (ret < 0) { | |
535 | return ret; | |
536 | } | |
537 | ||
538 | return ret / sizeof(struct lttng_domain); | |
539 | } | |
540 | ||
541 | /* | |
542 | * List channels of a session | |
543 | */ | |
544 | int lttng_list_channels(struct lttng_domain *domain, | |
545 | const char *session_name, struct lttng_channel **channels) | |
546 | { | |
547 | int ret; | |
548 | ||
42abccdb | 549 | copy_string(lsm.session.name, session_name, NAME_MAX); |
eb354453 | 550 | copy_lttng_domain(domain); |
9f19cc17 DG |
551 | |
552 | ret = ask_sessiond(LTTNG_LIST_CHANNELS, (void**) channels); | |
553 | if (ret < 0) { | |
554 | return ret; | |
555 | } | |
556 | ||
557 | return ret / sizeof(struct lttng_channel); | |
558 | } | |
559 | ||
560 | /* | |
561 | * List events of a session channel. | |
562 | */ | |
563 | int lttng_list_events(struct lttng_domain *domain, | |
564 | const char *session_name, const char *channel_name, | |
565 | struct lttng_event **events) | |
566 | { | |
567 | int ret; | |
568 | ||
42abccdb | 569 | copy_string(lsm.session.name, session_name, NAME_MAX); |
eb354453 DG |
570 | copy_string(lsm.u.list.channel_name, channel_name, NAME_MAX); |
571 | copy_lttng_domain(domain); | |
9f19cc17 DG |
572 | |
573 | ret = ask_sessiond(LTTNG_LIST_EVENTS, (void**) events); | |
574 | if (ret < 0) { | |
575 | return ret; | |
576 | } | |
577 | ||
578 | return ret / sizeof(struct lttng_event); | |
579 | } | |
580 | ||
7d29a247 DG |
581 | /* |
582 | * Set session name for the current lsm. | |
583 | */ | |
38057ed1 | 584 | void lttng_set_session_name(const char *name) |
e8be5f4f | 585 | { |
42abccdb | 586 | copy_string(lsm.session.name, name, NAME_MAX); |
e8be5f4f DG |
587 | } |
588 | ||
fac6795d DG |
589 | /* |
590 | * lttng_set_tracing_group | |
591 | * | |
592 | * Set tracing group variable with name. This function | |
593 | * allocate memory pointed by tracing_group. | |
594 | */ | |
595 | int lttng_set_tracing_group(const char *name) | |
596 | { | |
597 | if (asprintf(&tracing_group, "%s", name) < 0) { | |
598 | return -ENOMEM; | |
599 | } | |
600 | ||
601 | return 0; | |
602 | } | |
603 | ||
604 | /* | |
605 | * lttng_check_session_daemon | |
606 | * | |
947308c4 DG |
607 | * Yes, return 1 |
608 | * No, return 0 | |
609 | * Error, return negative value | |
fac6795d | 610 | */ |
947308c4 | 611 | int lttng_session_daemon_alive(void) |
fac6795d DG |
612 | { |
613 | int ret; | |
614 | ||
615 | ret = set_session_daemon_path(); | |
616 | if (ret < 0) { | |
947308c4 | 617 | /* Error */ |
fac6795d DG |
618 | return ret; |
619 | } | |
620 | ||
621 | /* If socket exist, we consider the daemon started */ | |
622 | ret = access(sessiond_sock_path, F_OK); | |
623 | if (ret < 0) { | |
947308c4 DG |
624 | /* Not alive */ |
625 | return 0; | |
fac6795d DG |
626 | } |
627 | ||
947308c4 DG |
628 | /* Is alive */ |
629 | return 1; | |
fac6795d DG |
630 | } |
631 | ||
632 | /* | |
633 | * lib constructor | |
634 | */ | |
635 | static void __attribute__((constructor)) init() | |
636 | { | |
637 | /* Set default session group */ | |
64a23ac4 | 638 | lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP); |
fac6795d | 639 | } |