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 | ||
1df4dedd | 281 | /* |
f3ed775e | 282 | * Start tracing for all trace of the session. |
1df4dedd | 283 | */ |
38057ed1 | 284 | int lttng_start_tracing(const char *session_name) |
f3ed775e DG |
285 | { |
286 | strncpy(lsm.session_name, session_name, NAME_MAX); | |
287 | return ask_sessiond(LTTNG_START_TRACE, NULL); | |
288 | } | |
1df4dedd DG |
289 | |
290 | /* | |
f3ed775e DG |
291 | * Stop tracing for all trace of the session. |
292 | */ | |
38057ed1 | 293 | int lttng_stop_tracing(const char *session_name) |
f3ed775e DG |
294 | { |
295 | strncpy(lsm.session_name, session_name, NAME_MAX); | |
296 | return ask_sessiond(LTTNG_STOP_TRACE, NULL); | |
297 | } | |
298 | ||
299 | /* | |
7d29a247 | 300 | * lttng_add_context |
1df4dedd | 301 | */ |
7d29a247 | 302 | int lttng_add_context(struct lttng_domain *domain, |
38057ed1 DG |
303 | struct lttng_event_context *ctx, const char *event_name, |
304 | const char *channel_name) | |
d65106b1 | 305 | { |
7d29a247 DG |
306 | int ret; |
307 | ||
94cf3c47 | 308 | if (channel_name != NULL) { |
d65106b1 DG |
309 | strncpy(lsm.u.context.channel_name, channel_name, NAME_MAX); |
310 | } | |
311 | ||
94cf3c47 | 312 | if (event_name != NULL) { |
d65106b1 DG |
313 | strncpy(lsm.u.context.event_name, event_name, NAME_MAX); |
314 | } | |
315 | ||
7d29a247 DG |
316 | memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context)); |
317 | ||
318 | switch (domain->type) { | |
319 | case LTTNG_DOMAIN_KERNEL: | |
320 | ret = ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT, NULL); | |
321 | break; | |
322 | case LTTNG_DOMAIN_UST: | |
323 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
324 | break; | |
325 | default: | |
326 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
327 | break; | |
328 | }; | |
329 | ||
330 | return ret; | |
d65106b1 DG |
331 | } |
332 | ||
f3ed775e | 333 | /* |
7d29a247 | 334 | * lttng_enable_event |
f3ed775e | 335 | */ |
7d29a247 | 336 | int lttng_enable_event(struct lttng_domain *domain, |
38057ed1 | 337 | struct lttng_event *ev, const char *channel_name) |
1df4dedd | 338 | { |
33a2b854 DG |
339 | int ret; |
340 | ||
94cf3c47 | 341 | if (channel_name == NULL) { |
f3ed775e | 342 | strncpy(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
33a2b854 | 343 | } else { |
f3ed775e DG |
344 | strncpy(lsm.u.enable.channel_name, channel_name, NAME_MAX); |
345 | } | |
346 | ||
7d29a247 DG |
347 | switch (domain->type) { |
348 | case LTTNG_DOMAIN_KERNEL: | |
349 | if (ev == NULL) { | |
350 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL); | |
351 | } else { | |
352 | memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event)); | |
353 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL); | |
354 | } | |
355 | break; | |
356 | case LTTNG_DOMAIN_UST: | |
357 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
358 | break; | |
359 | default: | |
360 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
361 | break; | |
362 | }; | |
33a2b854 DG |
363 | |
364 | return ret; | |
1df4dedd DG |
365 | } |
366 | ||
367 | /* | |
7d29a247 | 368 | * Disable an event in the kernel tracer. |
1df4dedd | 369 | */ |
38057ed1 DG |
370 | int lttng_disable_event(struct lttng_domain *domain, const char *name, |
371 | const char *channel_name) | |
1df4dedd | 372 | { |
f3ed775e | 373 | int ret; |
1df4dedd | 374 | |
94cf3c47 | 375 | if (channel_name == NULL) { |
f3ed775e DG |
376 | strncpy(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
377 | } else { | |
378 | strncpy(lsm.u.disable.channel_name, channel_name, NAME_MAX); | |
379 | } | |
380 | ||
7d29a247 DG |
381 | switch (domain->type) { |
382 | case LTTNG_DOMAIN_KERNEL: | |
383 | if (name == NULL) { | |
384 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT, NULL); | |
385 | } else { | |
386 | strncpy(lsm.u.disable.name, name, NAME_MAX); | |
387 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_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 DG |
397 | |
398 | return ret; | |
1df4dedd DG |
399 | } |
400 | ||
401 | /* | |
7d29a247 | 402 | * Enable recording for a channel for the kernel tracer. |
a5c5a2bd | 403 | */ |
38057ed1 DG |
404 | int lttng_enable_channel(struct lttng_domain *domain, |
405 | struct lttng_channel *chan) | |
a5c5a2bd | 406 | { |
7d29a247 | 407 | int ret; |
8c0faa1d | 408 | |
f3ed775e | 409 | memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel)); |
7d29a247 DG |
410 | |
411 | switch (domain->type) { | |
412 | case LTTNG_DOMAIN_KERNEL: | |
413 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL); | |
414 | break; | |
415 | case LTTNG_DOMAIN_UST: | |
416 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
417 | break; | |
418 | default: | |
419 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
420 | break; | |
421 | }; | |
422 | ||
423 | return ret; | |
8c0faa1d | 424 | } |
1df4dedd | 425 | |
2ef84c95 | 426 | /* |
7d29a247 | 427 | * Disable recording for the channel for the kernel tracer. |
2ef84c95 | 428 | */ |
38057ed1 | 429 | int lttng_disable_channel(struct lttng_domain *domain, const char *name) |
2ef84c95 | 430 | { |
7d29a247 | 431 | int ret; |
2ef84c95 | 432 | |
7d29a247 | 433 | strncpy(lsm.u.disable.channel_name, name, NAME_MAX); |
1df4dedd | 434 | |
7d29a247 DG |
435 | switch (domain->type) { |
436 | case LTTNG_DOMAIN_KERNEL: | |
437 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL, NULL); | |
438 | break; | |
439 | case LTTNG_DOMAIN_UST: | |
440 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
441 | break; | |
442 | default: | |
443 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
444 | break; | |
445 | }; | |
ca95a216 | 446 | |
7d29a247 | 447 | return ret; |
ca95a216 DG |
448 | } |
449 | ||
fac6795d | 450 | /* |
7d29a247 | 451 | * List all available events in the kernel. |
fac6795d | 452 | * |
7d29a247 DG |
453 | * Return the size (bytes) of the list and set the event_list array. |
454 | * On error, return negative value. | |
fac6795d | 455 | */ |
7d29a247 | 456 | int lttng_list_events(struct lttng_domain *domain, char **event_list) |
fac6795d | 457 | { |
ca95a216 | 458 | int ret; |
fac6795d | 459 | |
7d29a247 DG |
460 | switch (domain->type) { |
461 | case LTTNG_DOMAIN_KERNEL: | |
462 | ret = ask_sessiond(LTTNG_KERNEL_LIST_EVENTS, (void **) event_list); | |
463 | break; | |
464 | case LTTNG_DOMAIN_UST: | |
465 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
466 | break; | |
467 | default: | |
468 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
469 | break; | |
470 | }; | |
fac6795d | 471 | |
7d29a247 | 472 | return ret; |
fac6795d DG |
473 | } |
474 | ||
1657e9bb | 475 | /* |
7d29a247 | 476 | * Return a human readable string of code |
1657e9bb | 477 | */ |
7d29a247 | 478 | const char *lttng_get_readable_code(int code) |
1657e9bb | 479 | { |
7d29a247 DG |
480 | if (code > -LTTCOMM_OK) { |
481 | return "Ended with errors"; | |
1657e9bb DG |
482 | } |
483 | ||
7d29a247 | 484 | return lttcomm_get_readable_code(code); |
1657e9bb DG |
485 | } |
486 | ||
aaf97519 | 487 | /* |
894be886 | 488 | * Create a brand new session using name. |
aaf97519 | 489 | */ |
38057ed1 | 490 | int lttng_create_session(const char *name, const char *path) |
aaf97519 | 491 | { |
947308c4 | 492 | strncpy(lsm.session_name, name, NAME_MAX); |
f3ed775e | 493 | strncpy(lsm.path, path, PATH_MAX); |
947308c4 | 494 | return ask_sessiond(LTTNG_CREATE_SESSION, NULL); |
8028d920 DG |
495 | } |
496 | ||
497 | /* | |
8028d920 DG |
498 | * Destroy session using name. |
499 | */ | |
38057ed1 | 500 | int lttng_destroy_session(const char *name) |
8028d920 | 501 | { |
f3ed775e | 502 | strncpy(lsm.session_name, name, NAME_MAX); |
947308c4 | 503 | return ask_sessiond(LTTNG_DESTROY_SESSION, NULL); |
aaf97519 DG |
504 | } |
505 | ||
57167058 | 506 | /* |
57167058 DG |
507 | * Ask the session daemon for all available sessions. |
508 | * | |
ca95a216 DG |
509 | * Return number of session. |
510 | * On error, return negative value. | |
57167058 | 511 | */ |
ca95a216 | 512 | int lttng_list_sessions(struct lttng_session **sessions) |
57167058 | 513 | { |
ca95a216 | 514 | int ret; |
57167058 | 515 | |
ca95a216 | 516 | ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions); |
57167058 | 517 | if (ret < 0) { |
ca95a216 | 518 | return ret; |
57167058 DG |
519 | } |
520 | ||
ca95a216 | 521 | return ret / sizeof(struct lttng_session); |
57167058 DG |
522 | } |
523 | ||
7d29a247 DG |
524 | /* |
525 | * Set session name for the current lsm. | |
526 | */ | |
38057ed1 | 527 | void lttng_set_session_name(const char *name) |
e8be5f4f | 528 | { |
f3ed775e | 529 | strncpy(lsm.session_name, name, NAME_MAX); |
e8be5f4f DG |
530 | } |
531 | ||
fac6795d DG |
532 | /* |
533 | * lttng_set_tracing_group | |
534 | * | |
535 | * Set tracing group variable with name. This function | |
536 | * allocate memory pointed by tracing_group. | |
537 | */ | |
538 | int lttng_set_tracing_group(const char *name) | |
539 | { | |
540 | if (asprintf(&tracing_group, "%s", name) < 0) { | |
541 | return -ENOMEM; | |
542 | } | |
543 | ||
544 | return 0; | |
545 | } | |
546 | ||
547 | /* | |
548 | * lttng_check_session_daemon | |
549 | * | |
947308c4 DG |
550 | * Yes, return 1 |
551 | * No, return 0 | |
552 | * Error, return negative value | |
fac6795d | 553 | */ |
947308c4 | 554 | int lttng_session_daemon_alive(void) |
fac6795d DG |
555 | { |
556 | int ret; | |
557 | ||
558 | ret = set_session_daemon_path(); | |
559 | if (ret < 0) { | |
947308c4 | 560 | /* Error */ |
fac6795d DG |
561 | return ret; |
562 | } | |
563 | ||
564 | /* If socket exist, we consider the daemon started */ | |
565 | ret = access(sessiond_sock_path, F_OK); | |
566 | if (ret < 0) { | |
947308c4 DG |
567 | /* Not alive */ |
568 | return 0; | |
fac6795d DG |
569 | } |
570 | ||
947308c4 DG |
571 | /* Is alive */ |
572 | return 1; | |
fac6795d DG |
573 | } |
574 | ||
575 | /* | |
576 | * lib constructor | |
577 | */ | |
578 | static void __attribute__((constructor)) init() | |
579 | { | |
580 | /* Set default session group */ | |
64a23ac4 | 581 | lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP); |
fac6795d | 582 | } |