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 | ||
211 | /* | |
212 | * ask_sessiond | |
213 | * | |
214 | * Ask the session daemon a specific command and put the data into buf. | |
215 | * | |
216 | * Return size of data (only payload, not header). | |
217 | */ | |
218 | static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf) | |
219 | { | |
220 | int ret; | |
221 | size_t size; | |
222 | void *data = NULL; | |
223 | ||
224 | ret = connect_sessiond(); | |
225 | if (ret < 0) { | |
226 | goto end; | |
227 | } | |
228 | ||
229 | lsm.cmd_type = lct; | |
230 | ||
231 | /* Send command to session daemon */ | |
232 | ret = send_data_sessiond(); | |
233 | if (ret < 0) { | |
234 | goto end; | |
235 | } | |
236 | ||
237 | /* Get header from data transmission */ | |
238 | ret = recv_data_sessiond(&llm, sizeof(llm)); | |
239 | if (ret < 0) { | |
240 | goto end; | |
241 | } | |
242 | ||
243 | /* Check error code if OK */ | |
244 | if (llm.ret_code != LTTCOMM_OK) { | |
245 | ret = -llm.ret_code; | |
246 | goto end; | |
247 | } | |
248 | ||
249 | size = llm.data_size; | |
250 | if (size == 0) { | |
7d29a247 | 251 | ret = 0; |
65beb5ff DG |
252 | goto end; |
253 | } | |
254 | ||
255 | data = (void*) malloc(size); | |
256 | ||
257 | /* Get payload data */ | |
258 | ret = recv_data_sessiond(data, size); | |
259 | if (ret < 0) { | |
260 | free(data); | |
261 | goto end; | |
262 | } | |
263 | ||
264 | *buf = data; | |
265 | ret = size; | |
266 | ||
267 | end: | |
268 | disconnect_sessiond(); | |
269 | return ret; | |
270 | } | |
271 | ||
1df4dedd | 272 | /* |
f3ed775e | 273 | * Start tracing for all trace of the session. |
1df4dedd | 274 | */ |
38057ed1 | 275 | int lttng_start_tracing(const char *session_name) |
f3ed775e DG |
276 | { |
277 | strncpy(lsm.session_name, session_name, NAME_MAX); | |
278 | return ask_sessiond(LTTNG_START_TRACE, NULL); | |
279 | } | |
1df4dedd DG |
280 | |
281 | /* | |
f3ed775e DG |
282 | * Stop tracing for all trace of the session. |
283 | */ | |
38057ed1 | 284 | int lttng_stop_tracing(const char *session_name) |
f3ed775e DG |
285 | { |
286 | strncpy(lsm.session_name, session_name, NAME_MAX); | |
287 | return ask_sessiond(LTTNG_STOP_TRACE, NULL); | |
288 | } | |
289 | ||
290 | /* | |
7d29a247 | 291 | * lttng_add_context |
1df4dedd | 292 | */ |
7d29a247 | 293 | int lttng_add_context(struct lttng_domain *domain, |
38057ed1 DG |
294 | struct lttng_event_context *ctx, const char *event_name, |
295 | const char *channel_name) | |
d65106b1 | 296 | { |
7d29a247 DG |
297 | int ret; |
298 | ||
94cf3c47 | 299 | if (channel_name != NULL) { |
d65106b1 DG |
300 | strncpy(lsm.u.context.channel_name, channel_name, NAME_MAX); |
301 | } | |
302 | ||
94cf3c47 | 303 | if (event_name != NULL) { |
d65106b1 DG |
304 | strncpy(lsm.u.context.event_name, event_name, NAME_MAX); |
305 | } | |
306 | ||
7d29a247 DG |
307 | memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context)); |
308 | ||
309 | switch (domain->type) { | |
310 | case LTTNG_DOMAIN_KERNEL: | |
311 | ret = ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT, NULL); | |
312 | break; | |
313 | case LTTNG_DOMAIN_UST: | |
314 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
315 | break; | |
316 | default: | |
317 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
318 | break; | |
319 | }; | |
320 | ||
321 | return ret; | |
d65106b1 DG |
322 | } |
323 | ||
f3ed775e | 324 | /* |
7d29a247 | 325 | * lttng_enable_event |
f3ed775e | 326 | */ |
7d29a247 | 327 | int lttng_enable_event(struct lttng_domain *domain, |
38057ed1 | 328 | struct lttng_event *ev, const char *channel_name) |
1df4dedd | 329 | { |
33a2b854 DG |
330 | int ret; |
331 | ||
94cf3c47 | 332 | if (channel_name == NULL) { |
f3ed775e | 333 | strncpy(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
33a2b854 | 334 | } else { |
f3ed775e DG |
335 | strncpy(lsm.u.enable.channel_name, channel_name, NAME_MAX); |
336 | } | |
337 | ||
7d29a247 DG |
338 | switch (domain->type) { |
339 | case LTTNG_DOMAIN_KERNEL: | |
340 | if (ev == NULL) { | |
341 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL); | |
342 | } else { | |
343 | memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event)); | |
344 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL); | |
345 | } | |
346 | break; | |
347 | case LTTNG_DOMAIN_UST: | |
348 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
349 | break; | |
350 | default: | |
351 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
352 | break; | |
353 | }; | |
33a2b854 DG |
354 | |
355 | return ret; | |
1df4dedd DG |
356 | } |
357 | ||
358 | /* | |
7d29a247 | 359 | * Disable an event in the kernel tracer. |
1df4dedd | 360 | */ |
38057ed1 DG |
361 | int lttng_disable_event(struct lttng_domain *domain, const char *name, |
362 | const char *channel_name) | |
1df4dedd | 363 | { |
f3ed775e | 364 | int ret; |
1df4dedd | 365 | |
94cf3c47 | 366 | if (channel_name == NULL) { |
f3ed775e DG |
367 | strncpy(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX); |
368 | } else { | |
369 | strncpy(lsm.u.disable.channel_name, channel_name, NAME_MAX); | |
370 | } | |
371 | ||
7d29a247 DG |
372 | switch (domain->type) { |
373 | case LTTNG_DOMAIN_KERNEL: | |
374 | if (name == NULL) { | |
375 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT, NULL); | |
376 | } else { | |
377 | strncpy(lsm.u.disable.name, name, NAME_MAX); | |
378 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT, NULL); | |
379 | } | |
380 | break; | |
381 | case LTTNG_DOMAIN_UST: | |
382 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
383 | break; | |
384 | default: | |
385 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
386 | break; | |
387 | }; | |
f3ed775e DG |
388 | |
389 | return ret; | |
1df4dedd DG |
390 | } |
391 | ||
392 | /* | |
7d29a247 | 393 | * Enable recording for a channel for the kernel tracer. |
a5c5a2bd | 394 | */ |
38057ed1 DG |
395 | int lttng_enable_channel(struct lttng_domain *domain, |
396 | struct lttng_channel *chan) | |
a5c5a2bd | 397 | { |
7d29a247 | 398 | int ret; |
8c0faa1d | 399 | |
f3ed775e | 400 | memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel)); |
7d29a247 DG |
401 | |
402 | switch (domain->type) { | |
403 | case LTTNG_DOMAIN_KERNEL: | |
404 | ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL); | |
405 | break; | |
406 | case LTTNG_DOMAIN_UST: | |
407 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
408 | break; | |
409 | default: | |
410 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
411 | break; | |
412 | }; | |
413 | ||
414 | return ret; | |
8c0faa1d | 415 | } |
1df4dedd | 416 | |
2ef84c95 | 417 | /* |
7d29a247 | 418 | * Disable recording for the channel for the kernel tracer. |
2ef84c95 | 419 | */ |
38057ed1 | 420 | int lttng_disable_channel(struct lttng_domain *domain, const char *name) |
2ef84c95 | 421 | { |
7d29a247 | 422 | int ret; |
2ef84c95 | 423 | |
7d29a247 | 424 | strncpy(lsm.u.disable.channel_name, name, NAME_MAX); |
1df4dedd | 425 | |
7d29a247 DG |
426 | switch (domain->type) { |
427 | case LTTNG_DOMAIN_KERNEL: | |
428 | ret = ask_sessiond(LTTNG_KERNEL_DISABLE_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 | }; | |
ca95a216 | 437 | |
7d29a247 | 438 | return ret; |
ca95a216 DG |
439 | } |
440 | ||
fac6795d | 441 | /* |
7d29a247 | 442 | * List all available events in the kernel. |
fac6795d | 443 | * |
7d29a247 DG |
444 | * Return the size (bytes) of the list and set the event_list array. |
445 | * On error, return negative value. | |
fac6795d | 446 | */ |
7d29a247 | 447 | int lttng_list_events(struct lttng_domain *domain, char **event_list) |
fac6795d | 448 | { |
ca95a216 | 449 | int ret; |
fac6795d | 450 | |
7d29a247 DG |
451 | switch (domain->type) { |
452 | case LTTNG_DOMAIN_KERNEL: | |
453 | ret = ask_sessiond(LTTNG_KERNEL_LIST_EVENTS, (void **) event_list); | |
454 | break; | |
455 | case LTTNG_DOMAIN_UST: | |
456 | ret = LTTCOMM_NOT_IMPLEMENTED; | |
457 | break; | |
458 | default: | |
459 | ret = LTTCOMM_UNKNOWN_DOMAIN; | |
460 | break; | |
461 | }; | |
fac6795d | 462 | |
7d29a247 | 463 | return ret; |
fac6795d DG |
464 | } |
465 | ||
1657e9bb | 466 | /* |
7d29a247 | 467 | * Return a human readable string of code |
1657e9bb | 468 | */ |
7d29a247 | 469 | const char *lttng_get_readable_code(int code) |
1657e9bb | 470 | { |
7d29a247 DG |
471 | if (code > -LTTCOMM_OK) { |
472 | return "Ended with errors"; | |
1657e9bb DG |
473 | } |
474 | ||
7d29a247 | 475 | return lttcomm_get_readable_code(code); |
1657e9bb DG |
476 | } |
477 | ||
aaf97519 | 478 | /* |
894be886 | 479 | * Create a brand new session using name. |
aaf97519 | 480 | */ |
38057ed1 | 481 | int lttng_create_session(const char *name, const char *path) |
aaf97519 | 482 | { |
947308c4 | 483 | strncpy(lsm.session_name, name, NAME_MAX); |
f3ed775e | 484 | strncpy(lsm.path, path, PATH_MAX); |
947308c4 | 485 | return ask_sessiond(LTTNG_CREATE_SESSION, NULL); |
8028d920 DG |
486 | } |
487 | ||
488 | /* | |
8028d920 DG |
489 | * Destroy session using name. |
490 | */ | |
38057ed1 | 491 | int lttng_destroy_session(const char *name) |
8028d920 | 492 | { |
f3ed775e | 493 | strncpy(lsm.session_name, name, NAME_MAX); |
947308c4 | 494 | return ask_sessiond(LTTNG_DESTROY_SESSION, NULL); |
aaf97519 DG |
495 | } |
496 | ||
57167058 | 497 | /* |
57167058 DG |
498 | * Ask the session daemon for all available sessions. |
499 | * | |
ca95a216 DG |
500 | * Return number of session. |
501 | * On error, return negative value. | |
57167058 | 502 | */ |
ca95a216 | 503 | int lttng_list_sessions(struct lttng_session **sessions) |
57167058 | 504 | { |
ca95a216 | 505 | int ret; |
57167058 | 506 | |
ca95a216 | 507 | ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions); |
57167058 | 508 | if (ret < 0) { |
ca95a216 | 509 | return ret; |
57167058 DG |
510 | } |
511 | ||
ca95a216 | 512 | return ret / sizeof(struct lttng_session); |
57167058 DG |
513 | } |
514 | ||
7d29a247 DG |
515 | /* |
516 | * Set session name for the current lsm. | |
517 | */ | |
38057ed1 | 518 | void lttng_set_session_name(const char *name) |
e8be5f4f | 519 | { |
f3ed775e | 520 | strncpy(lsm.session_name, name, NAME_MAX); |
e8be5f4f DG |
521 | } |
522 | ||
fac6795d DG |
523 | /* |
524 | * lttng_set_tracing_group | |
525 | * | |
526 | * Set tracing group variable with name. This function | |
527 | * allocate memory pointed by tracing_group. | |
528 | */ | |
529 | int lttng_set_tracing_group(const char *name) | |
530 | { | |
531 | if (asprintf(&tracing_group, "%s", name) < 0) { | |
532 | return -ENOMEM; | |
533 | } | |
534 | ||
535 | return 0; | |
536 | } | |
537 | ||
538 | /* | |
539 | * lttng_check_session_daemon | |
540 | * | |
947308c4 DG |
541 | * Yes, return 1 |
542 | * No, return 0 | |
543 | * Error, return negative value | |
fac6795d | 544 | */ |
947308c4 | 545 | int lttng_session_daemon_alive(void) |
fac6795d DG |
546 | { |
547 | int ret; | |
548 | ||
549 | ret = set_session_daemon_path(); | |
550 | if (ret < 0) { | |
947308c4 | 551 | /* Error */ |
fac6795d DG |
552 | return ret; |
553 | } | |
554 | ||
555 | /* If socket exist, we consider the daemon started */ | |
556 | ret = access(sessiond_sock_path, F_OK); | |
557 | if (ret < 0) { | |
947308c4 DG |
558 | /* Not alive */ |
559 | return 0; | |
fac6795d DG |
560 | } |
561 | ||
947308c4 DG |
562 | /* Is alive */ |
563 | return 1; | |
fac6795d DG |
564 | } |
565 | ||
566 | /* | |
567 | * lib constructor | |
568 | */ | |
569 | static void __attribute__((constructor)) init() | |
570 | { | |
571 | /* Set default session group */ | |
64a23ac4 | 572 | lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP); |
fac6795d | 573 | } |