Commit | Line | Data |
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826d496d MD |
1 | /* |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
fac6795d DG |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version 2 | |
7 | * of the License, or (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
fac6795d DG |
17 | */ |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <errno.h> | |
21 | #include <grp.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <unistd.h> | |
26 | ||
5b97ec60 | 27 | #include <lttng/lttng.h> |
fac6795d DG |
28 | |
29 | #include "liblttsessiondcomm.h" | |
30 | #include "lttngerr.h" | |
31 | ||
32 | /* Socket to session daemon for communication */ | |
33 | static int sessiond_socket; | |
34 | static char sessiond_sock_path[PATH_MAX]; | |
35 | ||
36 | /* Communication structure to ltt-sessiond */ | |
fac6795d | 37 | static struct lttcomm_session_msg lsm; |
5461b305 | 38 | static struct lttcomm_lttng_msg llm; |
fac6795d DG |
39 | |
40 | /* Prototypes */ | |
41 | static int check_tracing_group(const char *grp_name); | |
6abb15de | 42 | static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf); |
ca95a216 DG |
43 | static int recv_data_sessiond(void *buf, size_t len); |
44 | static int send_data_sessiond(void); | |
fac6795d | 45 | static int set_session_daemon_path(void); |
fac6795d DG |
46 | |
47 | /* Variables */ | |
48 | static char *tracing_group; | |
49 | static int connected; | |
50 | ||
51 | /* | |
ca95a216 | 52 | * send_data_sessiond |
fac6795d | 53 | * |
e065084a | 54 | * Send lttcomm_session_msg to the session daemon. |
fac6795d DG |
55 | * |
56 | * On success, return 0 | |
57 | * On error, return error code | |
58 | */ | |
ca95a216 | 59 | static int send_data_sessiond(void) |
fac6795d DG |
60 | { |
61 | int ret; | |
62 | ||
63 | if (!connected) { | |
e065084a DG |
64 | ret = -ENOTCONN; |
65 | goto end; | |
fac6795d DG |
66 | } |
67 | ||
68 | ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm)); | |
e065084a DG |
69 | |
70 | end: | |
71 | return ret; | |
72 | } | |
73 | ||
74 | /* | |
ca95a216 | 75 | * recv_data_sessiond |
e065084a DG |
76 | * |
77 | * Receive data from the sessiond socket. | |
78 | * | |
79 | * On success, return 0 | |
80 | * On error, return recv() error code | |
81 | */ | |
ca95a216 | 82 | static int recv_data_sessiond(void *buf, size_t len) |
e065084a DG |
83 | { |
84 | int ret; | |
85 | ||
86 | if (!connected) { | |
87 | ret = -ENOTCONN; | |
88 | goto end; | |
fac6795d DG |
89 | } |
90 | ||
ca95a216 | 91 | ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len); |
fac6795d | 92 | if (ret < 0) { |
e065084a | 93 | goto end; |
fac6795d DG |
94 | } |
95 | ||
e065084a | 96 | end: |
fac6795d DG |
97 | return ret; |
98 | } | |
99 | ||
100 | /* | |
ca95a216 | 101 | * ask_sessiond |
fac6795d | 102 | * |
ca95a216 DG |
103 | * Ask the session daemon a specific command |
104 | * and put the data into buf. | |
105 | * | |
106 | * Return size of data (only payload, not header). | |
fac6795d | 107 | */ |
6abb15de | 108 | static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf) |
fac6795d | 109 | { |
ca95a216 DG |
110 | int ret; |
111 | size_t size; | |
112 | void *data = NULL; | |
ca95a216 | 113 | |
7442b2ba DG |
114 | ret = lttng_connect_sessiond(); |
115 | if (ret < 0) { | |
116 | goto end; | |
117 | } | |
118 | ||
ca95a216 DG |
119 | lsm.cmd_type = lct; |
120 | ||
121 | /* Send command to session daemon */ | |
122 | ret = send_data_sessiond(); | |
123 | if (ret < 0) { | |
124 | goto end; | |
fac6795d DG |
125 | } |
126 | ||
ca95a216 | 127 | /* Get header from data transmission */ |
5461b305 | 128 | ret = recv_data_sessiond(&llm, sizeof(llm)); |
ca95a216 DG |
129 | if (ret < 0) { |
130 | goto end; | |
131 | } | |
fac6795d | 132 | |
ca95a216 | 133 | /* Check error code if OK */ |
5461b305 DG |
134 | if (llm.ret_code != LTTCOMM_OK) { |
135 | ret = -llm.ret_code; | |
ca95a216 DG |
136 | goto end; |
137 | } | |
fac6795d | 138 | |
5461b305 | 139 | size = llm.trace_name_offset + llm.data_size; |
ca95a216 DG |
140 | if (size == 0) { |
141 | goto end; | |
fac6795d DG |
142 | } |
143 | ||
ca95a216 DG |
144 | data = (void*) malloc(size); |
145 | ||
146 | /* Get payload data */ | |
147 | ret = recv_data_sessiond(data, size); | |
fac6795d DG |
148 | if (ret < 0) { |
149 | goto end; | |
150 | } | |
151 | ||
ca95a216 DG |
152 | *buf = data; |
153 | ret = size; | |
fac6795d DG |
154 | |
155 | end: | |
7442b2ba | 156 | lttng_disconnect_sessiond(); |
ca95a216 | 157 | memset(&lsm, 0, sizeof(lsm)); |
fac6795d DG |
158 | return ret; |
159 | } | |
160 | ||
1df4dedd DG |
161 | /* |
162 | * BEGIN KERNEL CONTROL | |
163 | */ | |
164 | ||
165 | /* | |
166 | * lttng_kernel_enable_event | |
167 | * | |
168 | * Enable an event in the kernel tracer. | |
169 | */ | |
170 | int lttng_kernel_enable_event(char *event_name) | |
171 | { | |
172 | strncpy(lsm.u.event.event_name, event_name, NAME_MAX); | |
173 | return ask_sessiond(KERNEL_ENABLE_EVENT, NULL); | |
174 | } | |
175 | ||
176 | /* | |
177 | * lttng_kernel_disable_event | |
178 | * | |
179 | * Disable an event in the kernel tracer. | |
180 | */ | |
181 | int lttng_kernel_disable_event(char *event_name) | |
182 | { | |
183 | strncpy(lsm.u.event.event_name, event_name, NAME_MAX); | |
184 | return ask_sessiond(KERNEL_DISABLE_EVENT, NULL); | |
185 | } | |
186 | ||
187 | /* | |
188 | * lttng_kernel_create_session | |
189 | * | |
190 | * Create a session in the kernel tracer. | |
191 | */ | |
192 | int lttng_kernel_create_session(void) | |
193 | { | |
194 | return ask_sessiond(KERNEL_CREATE_SESSION, NULL); | |
195 | } | |
196 | ||
197 | /* | |
198 | * lttng_kernel_create_channel | |
199 | * | |
200 | * Create a channel in the kernel tracer. | |
201 | */ | |
202 | int lttng_kernel_create_channel(int overwrite, | |
203 | u64 subbuf_size, u64 num_subbuf, | |
204 | unsigned int switch_timer_interval, | |
205 | unsigned int read_timer_interval) | |
206 | { | |
207 | /* Write setting to the session message */ | |
208 | lsm.u.create_channel.overwrite = overwrite; | |
209 | lsm.u.create_channel.subbuf_size = subbuf_size; | |
210 | lsm.u.create_channel.num_subbuf = num_subbuf; | |
211 | lsm.u.create_channel.switch_timer_interval = switch_timer_interval; | |
212 | lsm.u.create_channel.read_timer_interval = read_timer_interval; | |
213 | ||
214 | return ask_sessiond(KERNEL_CREATE_CHANNEL, NULL); | |
215 | } | |
216 | ||
217 | /* | |
218 | * lttng_kernel_start_tracing | |
219 | * | |
220 | * Start kernel tracing. | |
221 | */ | |
222 | int lttng_kernel_start_tracing(void) | |
223 | { | |
224 | return ask_sessiond(KERNEL_START_TRACE, NULL); | |
225 | } | |
226 | ||
227 | /* | |
228 | * lttng_kernel_stop_tracing | |
229 | * | |
230 | * Stop kernel tracing. | |
231 | */ | |
232 | int lttng_kernel_stop_tracing(void) | |
233 | { | |
234 | return ask_sessiond(KERNEL_STOP_TRACE, NULL); | |
235 | } | |
236 | ||
237 | /* | |
238 | * END KERNEL CONTROL | |
239 | */ | |
240 | ||
ca95a216 DG |
241 | /* |
242 | * lttng_get_readable_code | |
243 | * | |
244 | * Return a human readable string of code | |
245 | */ | |
246 | const char *lttng_get_readable_code(int code) | |
247 | { | |
248 | if (code > -LTTCOMM_OK) { | |
249 | return "Ended with errors"; | |
250 | } | |
251 | ||
252 | return lttcomm_get_readable_code(code); | |
253 | } | |
254 | ||
ce3d728c DG |
255 | /* |
256 | * lttng_ust_start_trace | |
257 | * | |
258 | * Request a trace start for pid. | |
259 | */ | |
260 | int lttng_ust_start_trace(pid_t pid) | |
261 | { | |
262 | int ret; | |
263 | ||
264 | lsm.pid = pid; | |
265 | ret = ask_sessiond(UST_START_TRACE, NULL); | |
266 | ||
267 | return ret; | |
268 | } | |
269 | ||
520ff687 DG |
270 | /* |
271 | * lttng_ust_stop_trace | |
272 | * | |
273 | * Request a trace stop for pid. | |
274 | */ | |
275 | int lttng_ust_stop_trace(pid_t pid) | |
276 | { | |
277 | int ret; | |
278 | ||
279 | lsm.pid = pid; | |
280 | ret = ask_sessiond(UST_STOP_TRACE, NULL); | |
281 | ||
282 | return ret; | |
283 | } | |
284 | ||
df0da139 DG |
285 | /* |
286 | * lttng_ust_create_trace | |
287 | * | |
288 | * Request a trace creation for pid. | |
289 | */ | |
290 | int lttng_ust_create_trace(pid_t pid) | |
291 | { | |
292 | int ret; | |
293 | ||
294 | lsm.pid = pid; | |
295 | ret = ask_sessiond(UST_CREATE_TRACE, NULL); | |
296 | ||
297 | return ret; | |
298 | } | |
299 | ||
fac6795d DG |
300 | /* |
301 | * lttng_ust_list_apps | |
302 | * | |
303 | * Ask the session daemon for all UST traceable | |
304 | * applications. | |
305 | * | |
ca95a216 DG |
306 | * Return the number of pids. |
307 | * On error, return negative value. | |
fac6795d | 308 | */ |
ca95a216 | 309 | int lttng_ust_list_apps(pid_t **pids) |
fac6795d | 310 | { |
ca95a216 | 311 | int ret; |
fac6795d | 312 | |
ca95a216 | 313 | ret = ask_sessiond(UST_LIST_APPS, (void**) pids); |
fac6795d | 314 | if (ret < 0) { |
ca95a216 | 315 | return ret; |
fac6795d DG |
316 | } |
317 | ||
ca95a216 | 318 | return ret / sizeof(pid_t); |
fac6795d DG |
319 | } |
320 | ||
1657e9bb DG |
321 | /* |
322 | * lttng_list_traces | |
323 | * | |
324 | * Ask the session daemon for all traces (kernel and ust) | |
325 | * for the session identified by uuid. | |
326 | * | |
327 | * Return the number of traces. | |
328 | */ | |
329 | int lttng_list_traces(uuid_t *uuid, struct lttng_trace **traces) | |
330 | { | |
331 | int ret; | |
332 | ||
5461b305 | 333 | uuid_copy(lsm.session_uuid, *uuid); |
1657e9bb DG |
334 | |
335 | ret = ask_sessiond(LTTNG_LIST_TRACES, (void **) traces); | |
336 | if (ret < 0) { | |
337 | return ret; | |
338 | } | |
339 | ||
340 | return ret / sizeof(struct lttng_trace); | |
341 | } | |
342 | ||
aaf97519 DG |
343 | /* |
344 | * lttng_create_session | |
345 | * | |
346 | * Create a brand new session using name. Allocate | |
347 | * the session_id param pointing to the UUID. | |
348 | */ | |
8028d920 | 349 | int lttng_create_session(char *name, uuid_t *session_id) |
aaf97519 DG |
350 | { |
351 | int ret; | |
aaf97519 DG |
352 | |
353 | strncpy(lsm.session_name, name, sizeof(lsm.session_name)); | |
8028d920 | 354 | lsm.session_name[sizeof(lsm.session_name) - 1] = '\0'; |
aaf97519 DG |
355 | |
356 | ret = ask_sessiond(LTTNG_CREATE_SESSION, NULL); | |
357 | if (ret < 0) { | |
358 | goto end; | |
359 | } | |
360 | ||
5461b305 | 361 | uuid_copy(*session_id, llm.session_uuid); |
aaf97519 | 362 | |
8028d920 DG |
363 | end: |
364 | return ret; | |
365 | } | |
366 | ||
367 | /* | |
368 | * lttng_destroy_session | |
369 | * | |
370 | * Destroy session using name. | |
371 | */ | |
372 | int lttng_destroy_session(uuid_t *uuid) | |
373 | { | |
374 | int ret; | |
375 | ||
5461b305 | 376 | uuid_copy(lsm.session_uuid, *uuid); |
8028d920 DG |
377 | |
378 | ret = ask_sessiond(LTTNG_DESTROY_SESSION, NULL); | |
379 | if (ret < 0) { | |
380 | goto end; | |
381 | } | |
aaf97519 DG |
382 | |
383 | end: | |
384 | return ret; | |
385 | } | |
386 | ||
57167058 DG |
387 | /* |
388 | * lttng_list_sessions | |
389 | * | |
390 | * Ask the session daemon for all available sessions. | |
391 | * | |
ca95a216 DG |
392 | * Return number of session. |
393 | * On error, return negative value. | |
57167058 | 394 | */ |
ca95a216 | 395 | int lttng_list_sessions(struct lttng_session **sessions) |
57167058 | 396 | { |
ca95a216 | 397 | int ret; |
57167058 | 398 | |
ca95a216 | 399 | ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions); |
57167058 | 400 | if (ret < 0) { |
ca95a216 | 401 | return ret; |
57167058 DG |
402 | } |
403 | ||
ca95a216 | 404 | return ret / sizeof(struct lttng_session); |
57167058 DG |
405 | } |
406 | ||
fac6795d DG |
407 | /* |
408 | * lttng_connect_sessiond | |
409 | * | |
410 | * Connect to the LTTng session daemon. | |
411 | * On success, return 0 | |
412 | * On error, return a negative value | |
413 | */ | |
414 | int lttng_connect_sessiond(void) | |
415 | { | |
416 | int ret; | |
417 | ||
418 | ret = set_session_daemon_path(); | |
419 | if (ret < 0) { | |
420 | return ret; | |
421 | } | |
422 | ||
423 | /* Connect to the sesssion daemon */ | |
424 | ret = lttcomm_connect_unix_sock(sessiond_sock_path); | |
425 | if (ret < 0) { | |
426 | return ret; | |
427 | } | |
428 | ||
429 | sessiond_socket = ret; | |
430 | connected = 1; | |
431 | ||
432 | return 0; | |
433 | } | |
434 | ||
87378cf5 DG |
435 | /* |
436 | * lttng_disconnect_sessiond | |
437 | * | |
438 | * Clean disconnect the session daemon. | |
439 | */ | |
440 | int lttng_disconnect_sessiond(void) | |
441 | { | |
442 | int ret = 0; | |
443 | ||
444 | if (connected) { | |
445 | ret = lttcomm_close_unix_sock(sessiond_socket); | |
446 | sessiond_socket = 0; | |
447 | connected = 0; | |
448 | } | |
449 | ||
450 | return ret; | |
451 | } | |
452 | ||
e8be5f4f DG |
453 | /* |
454 | * lttng_set_current_session_uuid | |
455 | * | |
456 | * Set the session uuid for current lsm. | |
457 | */ | |
96243366 | 458 | void lttng_set_current_session_uuid(uuid_t *uuid) |
e8be5f4f | 459 | { |
5461b305 | 460 | uuid_copy(lsm.session_uuid, *uuid); |
e8be5f4f DG |
461 | } |
462 | ||
fac6795d DG |
463 | /* |
464 | * lttng_set_tracing_group | |
465 | * | |
466 | * Set tracing group variable with name. This function | |
467 | * allocate memory pointed by tracing_group. | |
468 | */ | |
469 | int lttng_set_tracing_group(const char *name) | |
470 | { | |
471 | if (asprintf(&tracing_group, "%s", name) < 0) { | |
472 | return -ENOMEM; | |
473 | } | |
474 | ||
475 | return 0; | |
476 | } | |
477 | ||
478 | /* | |
479 | * lttng_check_session_daemon | |
480 | * | |
481 | * Return 0 if a sesssion daemon is available | |
482 | * else return -1 | |
483 | */ | |
484 | int lttng_check_session_daemon(void) | |
485 | { | |
486 | int ret; | |
487 | ||
488 | ret = set_session_daemon_path(); | |
489 | if (ret < 0) { | |
490 | return ret; | |
491 | } | |
492 | ||
493 | /* If socket exist, we consider the daemon started */ | |
494 | ret = access(sessiond_sock_path, F_OK); | |
495 | if (ret < 0) { | |
496 | return ret; | |
497 | } | |
498 | ||
499 | return 0; | |
500 | } | |
501 | ||
fac6795d DG |
502 | /* |
503 | * set_session_daemon_path | |
504 | * | |
505 | * Set sessiond socket path by putting it in | |
506 | * the global sessiond_sock_path variable. | |
507 | */ | |
508 | static int set_session_daemon_path(void) | |
509 | { | |
510 | int ret; | |
511 | ||
512 | /* Are we in the tracing group ? */ | |
513 | ret = check_tracing_group(tracing_group); | |
847177cd | 514 | if (ret < 0 && getuid() != 0) { |
fac6795d DG |
515 | if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK, |
516 | getenv("HOME")) < 0) { | |
517 | return -ENOMEM; | |
518 | } | |
519 | } else { | |
520 | strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK, | |
521 | sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK)); | |
522 | } | |
523 | ||
524 | return 0; | |
525 | } | |
526 | ||
527 | /* | |
528 | * check_tracing_group | |
529 | * | |
530 | * Check if the specified group name exist. | |
531 | * If yes, 0, else -1 | |
532 | */ | |
533 | static int check_tracing_group(const char *grp_name) | |
534 | { | |
535 | struct group *grp_tracing; /* no free(). See getgrnam(3) */ | |
536 | gid_t *grp_list; | |
537 | int grp_list_size, grp_id, i; | |
538 | int ret = -1; | |
539 | ||
540 | /* Get GID of group 'tracing' */ | |
541 | grp_tracing = getgrnam(grp_name); | |
542 | if (grp_tracing == NULL) { | |
543 | /* NULL means not found also. getgrnam(3) */ | |
544 | if (errno != 0) { | |
545 | perror("getgrnam"); | |
546 | } | |
547 | goto end; | |
548 | } | |
549 | ||
550 | /* Get number of supplementary group IDs */ | |
551 | grp_list_size = getgroups(0, NULL); | |
552 | if (grp_list_size < 0) { | |
553 | perror("getgroups"); | |
554 | goto end; | |
555 | } | |
556 | ||
557 | /* Alloc group list of the right size */ | |
558 | grp_list = malloc(grp_list_size * sizeof(gid_t)); | |
559 | grp_id = getgroups(grp_list_size, grp_list); | |
560 | if (grp_id < -1) { | |
561 | perror("getgroups"); | |
562 | goto free_list; | |
563 | } | |
564 | ||
565 | for (i = 0; i < grp_list_size; i++) { | |
566 | if (grp_list[i] == grp_tracing->gr_gid) { | |
567 | ret = 0; | |
568 | break; | |
569 | } | |
570 | } | |
571 | ||
572 | free_list: | |
573 | free(grp_list); | |
574 | ||
575 | end: | |
576 | return ret; | |
577 | } | |
578 | ||
579 | /* | |
580 | * lib constructor | |
581 | */ | |
582 | static void __attribute__((constructor)) init() | |
583 | { | |
584 | /* Set default session group */ | |
585 | lttng_set_tracing_group(DEFAULT_TRACING_GROUP); | |
586 | } |