Improve protection around strncpy and memcpy calls
[lttng-tools.git] / liblttngctl / liblttngctl.c
CommitLineData
826d496d 1/*
82a3637f
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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
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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
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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
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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
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32
33#include "liblttsessiondcomm.h"
34#include "lttngerr.h"
f3ed775e 35#include "lttng-share.h"
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36
37/* Socket to session daemon for communication */
38static int sessiond_socket;
39static char sessiond_sock_path[PATH_MAX];
40
41/* Communication structure to ltt-sessiond */
fac6795d 42static struct lttcomm_session_msg lsm;
5461b305 43static struct lttcomm_lttng_msg llm;
fac6795d 44
fac6795d
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45/* Variables */
46static char *tracing_group;
47static int connected;
48
49/*
ca95a216 50 * send_data_sessiond
fac6795d 51 *
e065084a 52 * Send lttcomm_session_msg to the session daemon.
fac6795d
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53 *
54 * On success, return 0
55 * On error, return error code
56 */
ca95a216 57static int send_data_sessiond(void)
fac6795d
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58{
59 int ret;
60
61 if (!connected) {
e065084a
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62 ret = -ENOTCONN;
63 goto end;
fac6795d
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64 }
65
66 ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
e065084a
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67
68end:
69 return ret;
70}
71
72/*
ca95a216 73 * recv_data_sessiond
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74 *
75 * Receive data from the sessiond socket.
76 *
77 * On success, return 0
78 * On error, return recv() error code
79 */
ca95a216 80static int recv_data_sessiond(void *buf, size_t len)
e065084a
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81{
82 int ret;
83
84 if (!connected) {
85 ret = -ENOTCONN;
86 goto end;
fac6795d
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87 }
88
ca95a216 89 ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
fac6795d 90
e065084a 91end:
fac6795d
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92 return ret;
93}
94
95/*
947308c4 96 * Check if the specified group name exist.
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97 *
98 * If yes return 0, else return -1.
947308c4
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99 */
100static 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
139free_list:
140 free(grp_list);
141
142end:
143 return ret;
144}
145
146/*
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147 * Set sessiond socket path by putting it in the global sessiond_sock_path
148 * variable.
947308c4
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149 */
150static 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
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169/*
170 * Connect to the LTTng session daemon.
171 *
172 * On success, return 0. On error, return -1.
173 */
174static 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 */
198static 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
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211/*
212 * Reset the session message structure.
213 */
214static void reset_session_msg(void)
215{
216 memset(&lsm, 0, sizeof(struct lttcomm_session_msg));
217}
218
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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 */
226static 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
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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
275end:
276 disconnect_sessiond();
35a6fdb7 277 reset_session_msg();
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278 return ret;
279}
280
9f19cc17 281/*
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282 * Copy domain to lttcomm_session_msg domain. If unknown domain, default domain
283 * will be the kernel.
9f19cc17 284 */
eb354453 285static void copy_lttng_domain(struct lttng_domain *dom)
9f19cc17 286{
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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 */
306static 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
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312 }
313}
314
1df4dedd 315/*
f3ed775e 316 * Start tracing for all trace of the session.
1df4dedd 317 */
38057ed1 318int lttng_start_tracing(const char *session_name)
f3ed775e 319{
eb354453 320 copy_string(lsm.session_name, session_name, NAME_MAX);
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321 return ask_sessiond(LTTNG_START_TRACE, NULL);
322}
1df4dedd
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323
324/*
f3ed775e
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325 * Stop tracing for all trace of the session.
326 */
38057ed1 327int lttng_stop_tracing(const char *session_name)
f3ed775e 328{
eb354453 329 copy_string(lsm.session_name, session_name, NAME_MAX);
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330 return ask_sessiond(LTTNG_STOP_TRACE, NULL);
331}
332
333/*
7d29a247 334 * lttng_add_context
1df4dedd 335 */
7d29a247 336int lttng_add_context(struct lttng_domain *domain,
38057ed1
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337 struct lttng_event_context *ctx, const char *event_name,
338 const char *channel_name)
d65106b1 339{
eb354453 340 int ret = -1;
7d29a247 341
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342 copy_string(lsm.u.context.channel_name, channel_name, NAME_MAX);
343 copy_string(lsm.u.context.event_name, event_name, NAME_MAX);
d65106b1 344
eb354453
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345 if (ctx) {
346 memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
d65106b1
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347 }
348
eb354453
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349 if (domain) {
350 switch (domain->type) {
351 case LTTNG_DOMAIN_KERNEL:
352 ret = ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT, NULL);
353 break;
354 case LTTNG_DOMAIN_UST:
355 ret = LTTCOMM_NOT_IMPLEMENTED;
356 break;
357 default:
358 ret = LTTCOMM_UNKNOWN_DOMAIN;
359 break;
360 };
361 }
7d29a247
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362
363 return ret;
d65106b1
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364}
365
f3ed775e 366/*
7d29a247 367 * lttng_enable_event
f3ed775e 368 */
7d29a247 369int lttng_enable_event(struct lttng_domain *domain,
38057ed1 370 struct lttng_event *ev, const char *channel_name)
1df4dedd 371{
eb354453 372 int ret = -1;
33a2b854 373
94cf3c47 374 if (channel_name == NULL) {
eb354453 375 copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
33a2b854 376 } else {
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377 copy_string(lsm.u.enable.channel_name, channel_name, NAME_MAX);
378 }
379
380 if (domain) {
381 switch (domain->type) {
382 case LTTNG_DOMAIN_KERNEL:
383 if (ev == NULL) {
384 ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL);
385 } else {
386 memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event));
387 ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL);
388 }
389 break;
390 case LTTNG_DOMAIN_UST:
391 ret = LTTCOMM_NOT_IMPLEMENTED;
392 break;
393 default:
394 ret = LTTCOMM_UNKNOWN_DOMAIN;
395 break;
396 };
f3ed775e
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397 }
398
33a2b854 399 return ret;
1df4dedd
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400}
401
402/*
7d29a247 403 * Disable an event in the kernel tracer.
1df4dedd 404 */
38057ed1
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405int lttng_disable_event(struct lttng_domain *domain, const char *name,
406 const char *channel_name)
1df4dedd 407{
eb354453 408 int ret = -1;
1df4dedd 409
94cf3c47 410 if (channel_name == NULL) {
eb354453 411 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
f3ed775e 412 } else {
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413 copy_string(lsm.u.disable.channel_name, channel_name, NAME_MAX);
414 }
415
416 if (domain) {
417 switch (domain->type) {
418 case LTTNG_DOMAIN_KERNEL:
419 if (name == NULL) {
420 ret = ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT, NULL);
421 } else {
422 copy_string(lsm.u.disable.name, name, NAME_MAX);
423 ret = ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT, NULL);
424 }
425 break;
426 case LTTNG_DOMAIN_UST:
427 ret = LTTCOMM_NOT_IMPLEMENTED;
428 break;
429 default:
430 ret = LTTCOMM_UNKNOWN_DOMAIN;
431 break;
432 };
f3ed775e
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433 }
434
f3ed775e 435 return ret;
1df4dedd
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436}
437
438/*
7d29a247 439 * Enable recording for a channel for the kernel tracer.
a5c5a2bd 440 */
38057ed1
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441int lttng_enable_channel(struct lttng_domain *domain,
442 struct lttng_channel *chan)
a5c5a2bd 443{
eb354453 444 int ret = -1;
8c0faa1d 445
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446 if (chan) {
447 memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel));
448 }
7d29a247 449
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450 if (domain) {
451 switch (domain->type) {
452 case LTTNG_DOMAIN_KERNEL:
453 ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL);
454 break;
455 case LTTNG_DOMAIN_UST:
456 ret = LTTCOMM_NOT_IMPLEMENTED;
457 break;
458 default:
459 ret = LTTCOMM_UNKNOWN_DOMAIN;
460 break;
461 };
462 }
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463
464 return ret;
8c0faa1d 465}
1df4dedd 466
2ef84c95 467/*
7d29a247 468 * Disable recording for the channel for the kernel tracer.
2ef84c95 469 */
38057ed1 470int lttng_disable_channel(struct lttng_domain *domain, const char *name)
2ef84c95 471{
eb354453 472 int ret = -1;
2ef84c95 473
eb354453 474 copy_string(lsm.u.disable.channel_name, name, NAME_MAX);
1df4dedd 475
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476 if (domain) {
477 switch (domain->type) {
478 case LTTNG_DOMAIN_KERNEL:
479 ret = ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL, NULL);
480 break;
481 case LTTNG_DOMAIN_UST:
482 ret = LTTCOMM_NOT_IMPLEMENTED;
483 break;
484 default:
485 ret = LTTCOMM_UNKNOWN_DOMAIN;
486 break;
487 };
488 }
ca95a216 489
7d29a247 490 return ret;
ca95a216
DG
491}
492
fac6795d 493/*
2a71efd5 494 * List all available tracepoints of domain.
fac6795d 495 *
2a71efd5 496 * Return the size (bytes) of the list and set the events array.
7d29a247 497 * On error, return negative value.
fac6795d 498 */
2a71efd5
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499int lttng_list_tracepoints(struct lttng_domain *domain,
500 struct lttng_event **events)
fac6795d 501{
eb354453 502 int ret = -1;
fac6795d 503
eb354453 504 copy_lttng_domain(domain);
2a71efd5 505
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506 if (domain) {
507 switch (domain->type) {
508 case LTTNG_DOMAIN_KERNEL:
509 ret = ask_sessiond(LTTNG_KERNEL_LIST_EVENTS, (void **) events);
510 break;
511 case LTTNG_DOMAIN_UST:
512 ret = LTTCOMM_NOT_IMPLEMENTED;
513 break;
514 default:
515 ret = LTTCOMM_UNKNOWN_DOMAIN;
516 break;
517 };
518 }
fac6795d 519
9f19cc17 520 return ret / sizeof(struct lttng_event);
fac6795d
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521}
522
1657e9bb 523/*
7d29a247 524 * Return a human readable string of code
1657e9bb 525 */
7d29a247 526const char *lttng_get_readable_code(int code)
1657e9bb 527{
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528 if (code > -LTTCOMM_OK) {
529 return "Ended with errors";
1657e9bb
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530 }
531
7d29a247 532 return lttcomm_get_readable_code(code);
1657e9bb
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533}
534
aaf97519 535/*
894be886 536 * Create a brand new session using name.
aaf97519 537 */
38057ed1 538int lttng_create_session(const char *name, const char *path)
aaf97519 539{
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540 copy_string(lsm.session_name, name, NAME_MAX);
541 copy_string(lsm.path, path, PATH_MAX);
947308c4 542 return ask_sessiond(LTTNG_CREATE_SESSION, NULL);
8028d920
DG
543}
544
545/*
8028d920
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546 * Destroy session using name.
547 */
38057ed1 548int lttng_destroy_session(const char *name)
8028d920 549{
eb354453 550 copy_string(lsm.session_name, name, NAME_MAX);
947308c4 551 return ask_sessiond(LTTNG_DESTROY_SESSION, NULL);
aaf97519
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552}
553
57167058 554/*
57167058
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555 * Ask the session daemon for all available sessions.
556 *
ca95a216
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557 * Return number of session.
558 * On error, return negative value.
57167058 559 */
ca95a216 560int lttng_list_sessions(struct lttng_session **sessions)
57167058 561{
ca95a216 562 int ret;
57167058 563
ca95a216 564 ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions);
57167058 565 if (ret < 0) {
ca95a216 566 return ret;
57167058
DG
567 }
568
ca95a216 569 return ret / sizeof(struct lttng_session);
57167058
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570}
571
9f19cc17
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572/*
573 * List domain of a session.
574 */
575int lttng_list_domains(const char *session_name, struct lttng_domain **domains)
576{
577 int ret;
578
eb354453 579 copy_string(lsm.session_name, session_name, NAME_MAX);
9f19cc17
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580 ret = ask_sessiond(LTTNG_LIST_DOMAINS, (void**) domains);
581 if (ret < 0) {
582 return ret;
583 }
584
585 return ret / sizeof(struct lttng_domain);
586}
587
588/*
589 * List channels of a session
590 */
591int lttng_list_channels(struct lttng_domain *domain,
592 const char *session_name, struct lttng_channel **channels)
593{
594 int ret;
595
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596 copy_string(lsm.session_name, session_name, NAME_MAX);
597 copy_lttng_domain(domain);
9f19cc17
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598
599 ret = ask_sessiond(LTTNG_LIST_CHANNELS, (void**) channels);
600 if (ret < 0) {
601 return ret;
602 }
603
604 return ret / sizeof(struct lttng_channel);
605}
606
607/*
608 * List events of a session channel.
609 */
610int lttng_list_events(struct lttng_domain *domain,
611 const char *session_name, const char *channel_name,
612 struct lttng_event **events)
613{
614 int ret;
615
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616 copy_string(lsm.session_name, session_name, NAME_MAX);
617 copy_string(lsm.u.list.channel_name, channel_name, NAME_MAX);
618 copy_lttng_domain(domain);
9f19cc17
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619
620 ret = ask_sessiond(LTTNG_LIST_EVENTS, (void**) events);
621 if (ret < 0) {
622 return ret;
623 }
624
625 return ret / sizeof(struct lttng_event);
626}
627
7d29a247
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628/*
629 * Set session name for the current lsm.
630 */
38057ed1 631void lttng_set_session_name(const char *name)
e8be5f4f 632{
eb354453 633 copy_string(lsm.session_name, name, NAME_MAX);
e8be5f4f
DG
634}
635
fac6795d
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636/*
637 * lttng_set_tracing_group
638 *
639 * Set tracing group variable with name. This function
640 * allocate memory pointed by tracing_group.
641 */
642int lttng_set_tracing_group(const char *name)
643{
644 if (asprintf(&tracing_group, "%s", name) < 0) {
645 return -ENOMEM;
646 }
647
648 return 0;
649}
650
651/*
652 * lttng_check_session_daemon
653 *
947308c4
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654 * Yes, return 1
655 * No, return 0
656 * Error, return negative value
fac6795d 657 */
947308c4 658int lttng_session_daemon_alive(void)
fac6795d
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659{
660 int ret;
661
662 ret = set_session_daemon_path();
663 if (ret < 0) {
947308c4 664 /* Error */
fac6795d
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665 return ret;
666 }
667
668 /* If socket exist, we consider the daemon started */
669 ret = access(sessiond_sock_path, F_OK);
670 if (ret < 0) {
947308c4
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671 /* Not alive */
672 return 0;
fac6795d
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673 }
674
947308c4
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675 /* Is alive */
676 return 1;
fac6795d
DG
677}
678
679/*
680 * lib constructor
681 */
682static void __attribute__((constructor)) init()
683{
684 /* Set default session group */
64a23ac4 685 lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
fac6795d 686}
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