4884b0294a0bfcc3aa73b67df222c6a08d845b74
[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl.c
1 /*
2 * liblttngctl.c
3 *
4 * Linux Trace Toolkit Control Library
5 *
6 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
7 *
8 * This library is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU Lesser General Public License, version 2.1 only,
10 * as published by the Free Software Foundation.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #define _GNU_SOURCE
23 #include <assert.h>
24 #include <grp.h>
25 #include <errno.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include <common/common.h>
32 #include <common/defaults.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <common/uri.h>
35 #include <lttng/lttng.h>
36
37 #include "filter/filter-ast.h"
38 #include "filter/filter-parser.h"
39 #include "filter/filter-bytecode.h"
40 #include "filter/memstream.h"
41
42 #ifdef DEBUG
43 static const int print_xml = 1;
44 #define dbg_printf(fmt, args...) \
45 printf("[debug liblttng-ctl] " fmt, ## args)
46 #else
47 static const int print_xml = 0;
48 #define dbg_printf(fmt, args...) \
49 do { \
50 /* do nothing but check printf format */ \
51 if (0) \
52 printf("[debug liblttnctl] " fmt, ## args); \
53 } while (0)
54 #endif
55
56
57 /* Socket to session daemon for communication */
58 static int sessiond_socket;
59 static char sessiond_sock_path[PATH_MAX];
60 static char health_sock_path[PATH_MAX];
61
62 /* Variables */
63 static char *tracing_group;
64 static int connected;
65
66 /* Global */
67
68 /*
69 * Those two variables are used by error.h to silent or control the verbosity of
70 * error message. They are global to the library so application linking with it
71 * are able to compile correctly and also control verbosity of the library.
72 */
73 int lttng_opt_quiet;
74 int lttng_opt_verbose;
75
76 static void set_default_url_attr(struct lttng_uri *uri,
77 enum lttng_stream_type stype)
78 {
79 uri->stype = stype;
80 if (uri->dtype != LTTNG_DST_PATH && uri->port == 0) {
81 uri->port = (stype == LTTNG_STREAM_CONTROL) ?
82 DEFAULT_NETWORK_CONTROL_PORT : DEFAULT_NETWORK_DATA_PORT;
83 }
84 }
85
86 /*
87 * Parse a string URL and creates URI(s) returning the size of the populated
88 * array.
89 */
90 static ssize_t parse_str_urls_to_uri(const char *ctrl_url, const char *data_url,
91 struct lttng_uri **uris)
92 {
93 int ret;
94 unsigned int equal = 1, idx = 0;
95 /* Add the "file://" size to the URL maximum size */
96 char url[PATH_MAX + 7];
97 ssize_t size_ctrl = 0, size_data = 0, size;
98 struct lttng_uri *ctrl_uris = NULL, *data_uris = NULL;
99 struct lttng_uri *tmp_uris = NULL;
100
101 /* No URL(s) is allowed. This means that the consumer will be disabled. */
102 if (ctrl_url == NULL && data_url == NULL) {
103 return 0;
104 }
105
106 /* Check if URLs are equal and if so, only use the control URL */
107 if (ctrl_url && data_url) {
108 equal = !strcmp(ctrl_url, data_url);
109 }
110
111 /*
112 * Since we allow the str_url to be a full local filesystem path, we are
113 * going to create a valid file:// URL if it's the case.
114 *
115 * Check if first character is a '/' or else reject the URL.
116 */
117 if (ctrl_url && ctrl_url[0] == '/') {
118 ret = snprintf(url, sizeof(url), "file://%s", ctrl_url);
119 if (ret < 0) {
120 PERROR("snprintf file url");
121 goto parse_error;
122 }
123 ctrl_url = url;
124 }
125
126 /* Parse the control URL if there is one */
127 if (ctrl_url) {
128 size_ctrl = uri_parse(ctrl_url, &ctrl_uris);
129 if (size_ctrl < 1) {
130 ERR("Unable to parse the URL %s", ctrl_url);
131 goto parse_error;
132 }
133
134 /* At this point, we know there is at least one URI in the array */
135 set_default_url_attr(&ctrl_uris[0], LTTNG_STREAM_CONTROL);
136
137 if (ctrl_uris[0].dtype == LTTNG_DST_PATH && data_url) {
138 ERR("Can not have a data URL when destination is file://");
139 goto error;
140 }
141
142 /* URL are not equal but the control URL uses a net:// protocol */
143 if (size_ctrl == 2) {
144 if (!equal) {
145 ERR("Control URL uses the net:// protocol and the data URL is "
146 "different. Not allowed.");
147 goto error;
148 } else {
149 set_default_url_attr(&ctrl_uris[1], LTTNG_STREAM_DATA);
150 /*
151 * The data_url and ctrl_url are equal and the ctrl_url
152 * contains a net:// protocol so we just skip the data part.
153 */
154 data_url = NULL;
155 }
156 }
157 }
158
159 if (data_url) {
160 /* We have to parse the data URL in this case */
161 size_data = uri_parse(data_url, &data_uris);
162 if (size_data < 1) {
163 ERR("Unable to parse the URL %s", data_url);
164 goto error;
165 } else if (size_data == 2) {
166 ERR("Data URL can not be set with the net[4|6]:// protocol");
167 goto error;
168 }
169
170 set_default_url_attr(&data_uris[0], LTTNG_STREAM_DATA);
171 }
172
173 /* Compute total size */
174 size = size_ctrl + size_data;
175
176 tmp_uris = zmalloc(sizeof(struct lttng_uri) * size);
177 if (tmp_uris == NULL) {
178 PERROR("zmalloc uris");
179 goto error;
180 }
181
182 if (ctrl_uris) {
183 /* It's possible the control URIs array contains more than one URI */
184 memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * size_ctrl);
185 ++idx;
186 }
187
188 if (data_uris) {
189 memcpy(&tmp_uris[idx], data_uris, sizeof(struct lttng_uri));
190 }
191
192 *uris = tmp_uris;
193
194 return size;
195
196 error:
197 free(ctrl_uris);
198 free(data_uris);
199 free(tmp_uris);
200 parse_error:
201 return -1;
202 }
203
204 /*
205 * Copy string from src to dst and enforce null terminated byte.
206 */
207 static void copy_string(char *dst, const char *src, size_t len)
208 {
209 if (src && dst) {
210 strncpy(dst, src, len);
211 /* Enforce the NULL terminated byte */
212 dst[len - 1] = '\0';
213 } else if (dst) {
214 dst[0] = '\0';
215 }
216 }
217
218 /*
219 * Copy domain to lttcomm_session_msg domain.
220 *
221 * If domain is unknown, default domain will be the kernel.
222 */
223 static void copy_lttng_domain(struct lttng_domain *dst, struct lttng_domain *src)
224 {
225 if (src && dst) {
226 switch (src->type) {
227 case LTTNG_DOMAIN_KERNEL:
228 case LTTNG_DOMAIN_UST:
229 /*
230 case LTTNG_DOMAIN_UST_EXEC_NAME:
231 case LTTNG_DOMAIN_UST_PID:
232 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
233 */
234 memcpy(dst, src, sizeof(struct lttng_domain));
235 break;
236 default:
237 memset(dst, 0, sizeof(struct lttng_domain));
238 break;
239 }
240 }
241 }
242
243 /*
244 * Send lttcomm_session_msg to the session daemon.
245 *
246 * On success, returns the number of bytes sent (>=0)
247 * On error, returns -1
248 */
249 static int send_session_msg(struct lttcomm_session_msg *lsm)
250 {
251 int ret;
252
253 if (!connected) {
254 ret = -LTTNG_ERR_NO_SESSIOND;
255 goto end;
256 }
257
258 DBG("LSM cmd type : %d", lsm->cmd_type);
259
260 ret = lttcomm_send_creds_unix_sock(sessiond_socket, lsm,
261 sizeof(struct lttcomm_session_msg));
262 if (ret < 0) {
263 ret = -LTTNG_ERR_FATAL;
264 }
265
266 end:
267 return ret;
268 }
269
270 /*
271 * Send var len data to the session daemon.
272 *
273 * On success, returns the number of bytes sent (>=0)
274 * On error, returns -1
275 */
276 static int send_session_varlen(void *data, size_t len)
277 {
278 int ret;
279
280 if (!connected) {
281 ret = -LTTNG_ERR_NO_SESSIOND;
282 goto end;
283 }
284
285 if (!data || !len) {
286 ret = 0;
287 goto end;
288 }
289
290 ret = lttcomm_send_unix_sock(sessiond_socket, data, len);
291 if (ret < 0) {
292 ret = -LTTNG_ERR_FATAL;
293 }
294
295 end:
296 return ret;
297 }
298
299 /*
300 * Receive data from the sessiond socket.
301 *
302 * On success, returns the number of bytes received (>=0)
303 * On error, returns -1 (recvmsg() error) or -ENOTCONN
304 */
305 static int recv_data_sessiond(void *buf, size_t len)
306 {
307 int ret;
308
309 if (!connected) {
310 ret = -LTTNG_ERR_NO_SESSIOND;
311 goto end;
312 }
313
314 ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
315 if (ret < 0) {
316 ret = -LTTNG_ERR_FATAL;
317 }
318
319 end:
320 return ret;
321 }
322
323 /*
324 * Check if we are in the specified group.
325 *
326 * If yes return 1, else return -1.
327 */
328 static int check_tracing_group(const char *grp_name)
329 {
330 struct group *grp_tracing; /* no free(). See getgrnam(3) */
331 gid_t *grp_list;
332 int grp_list_size, grp_id, i;
333 int ret = -1;
334
335 /* Get GID of group 'tracing' */
336 grp_tracing = getgrnam(grp_name);
337 if (!grp_tracing) {
338 /* If grp_tracing is NULL, the group does not exist. */
339 goto end;
340 }
341
342 /* Get number of supplementary group IDs */
343 grp_list_size = getgroups(0, NULL);
344 if (grp_list_size < 0) {
345 perror("getgroups");
346 goto end;
347 }
348
349 /* Alloc group list of the right size */
350 grp_list = malloc(grp_list_size * sizeof(gid_t));
351 if (!grp_list) {
352 perror("malloc");
353 goto end;
354 }
355 grp_id = getgroups(grp_list_size, grp_list);
356 if (grp_id < 0) {
357 perror("getgroups");
358 goto free_list;
359 }
360
361 for (i = 0; i < grp_list_size; i++) {
362 if (grp_list[i] == grp_tracing->gr_gid) {
363 ret = 1;
364 break;
365 }
366 }
367
368 free_list:
369 free(grp_list);
370
371 end:
372 return ret;
373 }
374
375 /*
376 * Try connect to session daemon with sock_path.
377 *
378 * Return 0 on success, else -1
379 */
380 static int try_connect_sessiond(const char *sock_path)
381 {
382 int ret;
383
384 /* If socket exist, we check if the daemon listens for connect. */
385 ret = access(sock_path, F_OK);
386 if (ret < 0) {
387 /* Not alive */
388 goto error;
389 }
390
391 ret = lttcomm_connect_unix_sock(sock_path);
392 if (ret < 0) {
393 /* Not alive */
394 goto error;
395 }
396
397 ret = lttcomm_close_unix_sock(ret);
398 if (ret < 0) {
399 perror("lttcomm_close_unix_sock");
400 }
401
402 return 0;
403
404 error:
405 return -1;
406 }
407
408 /*
409 * Set sessiond socket path by putting it in the global sessiond_sock_path
410 * variable.
411 *
412 * Returns 0 on success, negative value on failure (the sessiond socket path
413 * is somehow too long or ENOMEM).
414 */
415 static int set_session_daemon_path(void)
416 {
417 int ret;
418 int in_tgroup = 0; /* In tracing group */
419 uid_t uid;
420
421 uid = getuid();
422
423 if (uid != 0) {
424 /* Are we in the tracing group ? */
425 in_tgroup = check_tracing_group(tracing_group);
426 }
427
428 if ((uid == 0) || in_tgroup) {
429 copy_string(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
430 sizeof(sessiond_sock_path));
431 }
432
433 if (uid != 0) {
434 if (in_tgroup) {
435 /* Tracing group */
436 ret = try_connect_sessiond(sessiond_sock_path);
437 if (ret >= 0) {
438 goto end;
439 }
440 /* Global session daemon not available... */
441 }
442 /* ...or not in tracing group (and not root), default */
443
444 /*
445 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
446 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
447 */
448 ret = snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
449 DEFAULT_HOME_CLIENT_UNIX_SOCK, getenv("HOME"));
450 if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
451 goto error;
452 }
453 }
454 end:
455 return 0;
456
457 error:
458 return -1;
459 }
460
461 /*
462 * Connect to the LTTng session daemon.
463 *
464 * On success, return 0. On error, return -1.
465 */
466 static int connect_sessiond(void)
467 {
468 int ret;
469
470 ret = set_session_daemon_path();
471 if (ret < 0) {
472 goto error;
473 }
474
475 /* Connect to the sesssion daemon */
476 ret = lttcomm_connect_unix_sock(sessiond_sock_path);
477 if (ret < 0) {
478 goto error;
479 }
480
481 sessiond_socket = ret;
482 connected = 1;
483
484 return 0;
485
486 error:
487 return -1;
488 }
489
490 /*
491 * Clean disconnect from the session daemon.
492 * On success, return 0. On error, return -1.
493 */
494 static int disconnect_sessiond(void)
495 {
496 int ret = 0;
497
498 if (connected) {
499 ret = lttcomm_close_unix_sock(sessiond_socket);
500 sessiond_socket = 0;
501 connected = 0;
502 }
503
504 return ret;
505 }
506
507 /*
508 * Ask the session daemon a specific command and put the data into buf.
509 * Takes extra var. len. data as input to send to the session daemon.
510 *
511 * Return size of data (only payload, not header) or a negative error code.
512 */
513 static int ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
514 void *vardata, size_t varlen, void **buf)
515 {
516 int ret;
517 size_t size;
518 void *data = NULL;
519 struct lttcomm_lttng_msg llm;
520
521 ret = connect_sessiond();
522 if (ret < 0) {
523 ret = -LTTNG_ERR_NO_SESSIOND;
524 goto end;
525 }
526
527 /* Send command to session daemon */
528 ret = send_session_msg(lsm);
529 if (ret < 0) {
530 /* Ret value is a valid lttng error code. */
531 goto end;
532 }
533 /* Send var len data */
534 ret = send_session_varlen(vardata, varlen);
535 if (ret < 0) {
536 /* Ret value is a valid lttng error code. */
537 goto end;
538 }
539
540 /* Get header from data transmission */
541 ret = recv_data_sessiond(&llm, sizeof(llm));
542 if (ret < 0) {
543 /* Ret value is a valid lttng error code. */
544 goto end;
545 }
546
547 /* Check error code if OK */
548 if (llm.ret_code != LTTNG_OK) {
549 ret = -llm.ret_code;
550 goto end;
551 }
552
553 size = llm.data_size;
554 if (size == 0) {
555 /* If client free with size 0 */
556 if (buf != NULL) {
557 *buf = NULL;
558 }
559 ret = 0;
560 goto end;
561 }
562
563 data = (void*) malloc(size);
564
565 /* Get payload data */
566 ret = recv_data_sessiond(data, size);
567 if (ret < 0) {
568 free(data);
569 goto end;
570 }
571
572 /*
573 * Extra protection not to dereference a NULL pointer. If buf is NULL at
574 * this point, an error is returned and data is freed.
575 */
576 if (buf == NULL) {
577 ret = -LTTNG_ERR_INVALID;
578 free(data);
579 goto end;
580 }
581
582 *buf = data;
583 ret = size;
584
585 end:
586 disconnect_sessiond();
587 return ret;
588 }
589
590 /*
591 * Ask the session daemon a specific command and put the data into buf.
592 *
593 * Return size of data (only payload, not header) or a negative error code.
594 */
595 static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
596 {
597 return ask_sessiond_varlen(lsm, NULL, 0, buf);
598 }
599
600 /*
601 * Create lttng handle and return pointer.
602 * The returned pointer will be NULL in case of malloc() error.
603 */
604 struct lttng_handle *lttng_create_handle(const char *session_name,
605 struct lttng_domain *domain)
606 {
607 struct lttng_handle *handle = NULL;
608
609 if (domain == NULL) {
610 goto end;
611 }
612
613 handle = malloc(sizeof(struct lttng_handle));
614 if (handle == NULL) {
615 PERROR("malloc handle");
616 goto end;
617 }
618
619 /* Copy session name */
620 copy_string(handle->session_name, session_name,
621 sizeof(handle->session_name));
622
623 /* Copy lttng domain */
624 copy_lttng_domain(&handle->domain, domain);
625
626 end:
627 return handle;
628 }
629
630 /*
631 * Destroy handle by free(3) the pointer.
632 */
633 void lttng_destroy_handle(struct lttng_handle *handle)
634 {
635 if (handle) {
636 free(handle);
637 }
638 }
639
640 /*
641 * Register an outside consumer.
642 * Returns size of returned session payload data or a negative error code.
643 */
644 int lttng_register_consumer(struct lttng_handle *handle,
645 const char *socket_path)
646 {
647 struct lttcomm_session_msg lsm;
648
649 if (handle == NULL || socket_path == NULL) {
650 return -LTTNG_ERR_INVALID;
651 }
652
653 lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
654 copy_string(lsm.session.name, handle->session_name,
655 sizeof(lsm.session.name));
656 copy_lttng_domain(&lsm.domain, &handle->domain);
657
658 copy_string(lsm.u.reg.path, socket_path, sizeof(lsm.u.reg.path));
659
660 return ask_sessiond(&lsm, NULL);
661 }
662
663 /*
664 * Start tracing for all traces of the session.
665 * Returns size of returned session payload data or a negative error code.
666 */
667 int lttng_start_tracing(const char *session_name)
668 {
669 struct lttcomm_session_msg lsm;
670
671 if (session_name == NULL) {
672 return -LTTNG_ERR_INVALID;
673 }
674
675 lsm.cmd_type = LTTNG_START_TRACE;
676
677 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
678
679 return ask_sessiond(&lsm, NULL);
680 }
681
682 /*
683 * Stop tracing for all traces of the session.
684 */
685 static int _lttng_stop_tracing(const char *session_name, int wait)
686 {
687 int ret, data_ret;
688 struct lttcomm_session_msg lsm;
689
690 if (session_name == NULL) {
691 return -LTTNG_ERR_INVALID;
692 }
693
694 lsm.cmd_type = LTTNG_STOP_TRACE;
695
696 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
697
698 ret = ask_sessiond(&lsm, NULL);
699 if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
700 goto error;
701 }
702
703 if (!wait) {
704 goto end;
705 }
706
707 _MSG("Waiting for data availability");
708
709 /* Check for data availability */
710 do {
711 data_ret = lttng_data_pending(session_name);
712 if (data_ret < 0) {
713 /* Return the data available call error. */
714 ret = data_ret;
715 goto error;
716 }
717
718 /*
719 * Data sleep time before retrying (in usec). Don't sleep if the call
720 * returned value indicates availability.
721 */
722 if (data_ret) {
723 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
724 _MSG(".");
725 }
726 } while (data_ret != 0);
727
728 MSG("");
729
730 end:
731 error:
732 return ret;
733 }
734
735 /*
736 * Stop tracing and wait for data availability.
737 */
738 int lttng_stop_tracing(const char *session_name)
739 {
740 return _lttng_stop_tracing(session_name, 1);
741 }
742
743 /*
744 * Stop tracing but _don't_ wait for data availability.
745 */
746 int lttng_stop_tracing_no_wait(const char *session_name)
747 {
748 return _lttng_stop_tracing(session_name, 0);
749 }
750
751 /*
752 * Add context to a channel.
753 *
754 * If the given channel is NULL, add the contexts to all channels.
755 * The event_name param is ignored.
756 *
757 * Returns the size of the returned payload data or a negative error code.
758 */
759 int lttng_add_context(struct lttng_handle *handle,
760 struct lttng_event_context *ctx, const char *event_name,
761 const char *channel_name)
762 {
763 struct lttcomm_session_msg lsm;
764
765 /* Safety check. Both are mandatory */
766 if (handle == NULL || ctx == NULL) {
767 return -LTTNG_ERR_INVALID;
768 }
769
770 memset(&lsm, 0, sizeof(lsm));
771
772 lsm.cmd_type = LTTNG_ADD_CONTEXT;
773
774 /* Copy channel name */
775 copy_string(lsm.u.context.channel_name, channel_name,
776 sizeof(lsm.u.context.channel_name));
777
778 copy_lttng_domain(&lsm.domain, &handle->domain);
779
780 memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
781
782 copy_string(lsm.session.name, handle->session_name,
783 sizeof(lsm.session.name));
784
785 return ask_sessiond(&lsm, NULL);
786 }
787
788 /*
789 * Enable event(s) for a channel.
790 * If no event name is specified, all events are enabled.
791 * If no channel name is specified, the default 'channel0' is used.
792 * Returns size of returned session payload data or a negative error code.
793 */
794 int lttng_enable_event(struct lttng_handle *handle,
795 struct lttng_event *ev, const char *channel_name)
796 {
797 struct lttcomm_session_msg lsm;
798
799 if (handle == NULL || ev == NULL) {
800 return -LTTNG_ERR_INVALID;
801 }
802
803 memset(&lsm, 0, sizeof(lsm));
804
805 /* If no channel name, we put the default name */
806 if (channel_name == NULL) {
807 copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
808 sizeof(lsm.u.enable.channel_name));
809 } else {
810 copy_string(lsm.u.enable.channel_name, channel_name,
811 sizeof(lsm.u.enable.channel_name));
812 }
813
814 copy_lttng_domain(&lsm.domain, &handle->domain);
815
816 if (ev->name[0] != '\0') {
817 lsm.cmd_type = LTTNG_ENABLE_EVENT;
818 } else {
819 lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
820 }
821 memcpy(&lsm.u.enable.event, ev, sizeof(lsm.u.enable.event));
822
823 copy_string(lsm.session.name, handle->session_name,
824 sizeof(lsm.session.name));
825
826 return ask_sessiond(&lsm, NULL);
827 }
828
829 /*
830 * set filter for an event
831 * Return negative error value on error.
832 * Return size of returned session payload data if OK.
833 */
834
835 int lttng_set_event_filter(struct lttng_handle *handle,
836 const char *event_name, const char *channel_name,
837 const char *filter_expression)
838 {
839 struct lttcomm_session_msg lsm;
840 struct filter_parser_ctx *ctx;
841 FILE *fmem;
842 int ret = 0;
843
844 /* Safety check. */
845 if (handle == NULL) {
846 return -LTTNG_ERR_INVALID;
847 }
848
849 if (!filter_expression) {
850 return 0;
851 }
852
853 /*
854 * casting const to non-const, as the underlying function will
855 * use it in read-only mode.
856 */
857 fmem = lttng_fmemopen((void *) filter_expression,
858 strlen(filter_expression), "r");
859 if (!fmem) {
860 fprintf(stderr, "Error opening memory as stream\n");
861 return -LTTNG_ERR_FILTER_NOMEM;
862 }
863 ctx = filter_parser_ctx_alloc(fmem);
864 if (!ctx) {
865 fprintf(stderr, "Error allocating parser\n");
866 ret = -LTTNG_ERR_FILTER_NOMEM;
867 goto alloc_error;
868 }
869 ret = filter_parser_ctx_append_ast(ctx);
870 if (ret) {
871 fprintf(stderr, "Parse error\n");
872 ret = -LTTNG_ERR_FILTER_INVAL;
873 goto parse_error;
874 }
875 ret = filter_visitor_set_parent(ctx);
876 if (ret) {
877 fprintf(stderr, "Set parent error\n");
878 ret = -LTTNG_ERR_FILTER_INVAL;
879 goto parse_error;
880 }
881 if (print_xml) {
882 ret = filter_visitor_print_xml(ctx, stdout, 0);
883 if (ret) {
884 fflush(stdout);
885 fprintf(stderr, "XML print error\n");
886 ret = -LTTNG_ERR_FILTER_INVAL;
887 goto parse_error;
888 }
889 }
890
891 dbg_printf("Generating IR... ");
892 fflush(stdout);
893 ret = filter_visitor_ir_generate(ctx);
894 if (ret) {
895 fprintf(stderr, "Generate IR error\n");
896 ret = -LTTNG_ERR_FILTER_INVAL;
897 goto parse_error;
898 }
899 dbg_printf("done\n");
900
901 dbg_printf("Validating IR... ");
902 fflush(stdout);
903 ret = filter_visitor_ir_check_binary_op_nesting(ctx);
904 if (ret) {
905 ret = -LTTNG_ERR_FILTER_INVAL;
906 goto parse_error;
907 }
908 dbg_printf("done\n");
909
910 dbg_printf("Generating bytecode... ");
911 fflush(stdout);
912 ret = filter_visitor_bytecode_generate(ctx);
913 if (ret) {
914 fprintf(stderr, "Generate bytecode error\n");
915 ret = -LTTNG_ERR_FILTER_INVAL;
916 goto parse_error;
917 }
918 dbg_printf("done\n");
919 dbg_printf("Size of bytecode generated: %u bytes.\n",
920 bytecode_get_len(&ctx->bytecode->b));
921
922 memset(&lsm, 0, sizeof(lsm));
923
924 lsm.cmd_type = LTTNG_SET_FILTER;
925
926 /* Copy channel name */
927 copy_string(lsm.u.filter.channel_name, channel_name,
928 sizeof(lsm.u.filter.channel_name));
929 /* Copy event name */
930 copy_string(lsm.u.filter.event_name, event_name,
931 sizeof(lsm.u.filter.event_name));
932 lsm.u.filter.bytecode_len = sizeof(ctx->bytecode->b)
933 + bytecode_get_len(&ctx->bytecode->b);
934
935 copy_lttng_domain(&lsm.domain, &handle->domain);
936
937 copy_string(lsm.session.name, handle->session_name,
938 sizeof(lsm.session.name));
939
940 ret = ask_sessiond_varlen(&lsm, &ctx->bytecode->b,
941 lsm.u.filter.bytecode_len, NULL);
942
943 filter_bytecode_free(ctx);
944 filter_ir_free(ctx);
945 filter_parser_ctx_free(ctx);
946 if (fclose(fmem) != 0) {
947 perror("fclose");
948 }
949 return ret;
950
951 parse_error:
952 filter_bytecode_free(ctx);
953 filter_ir_free(ctx);
954 filter_parser_ctx_free(ctx);
955 alloc_error:
956 if (fclose(fmem) != 0) {
957 perror("fclose");
958 }
959 return ret;
960 }
961
962 /*
963 * Disable event(s) of a channel and domain.
964 * If no event name is specified, all events are disabled.
965 * If no channel name is specified, the default 'channel0' is used.
966 * Returns size of returned session payload data or a negative error code.
967 */
968 int lttng_disable_event(struct lttng_handle *handle, const char *name,
969 const char *channel_name)
970 {
971 struct lttcomm_session_msg lsm;
972
973 if (handle == NULL) {
974 return -LTTNG_ERR_INVALID;
975 }
976
977 memset(&lsm, 0, sizeof(lsm));
978
979 if (channel_name) {
980 copy_string(lsm.u.disable.channel_name, channel_name,
981 sizeof(lsm.u.disable.channel_name));
982 } else {
983 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
984 sizeof(lsm.u.disable.channel_name));
985 }
986
987 copy_lttng_domain(&lsm.domain, &handle->domain);
988
989 if (name != NULL) {
990 copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
991 lsm.cmd_type = LTTNG_DISABLE_EVENT;
992 } else {
993 lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
994 }
995
996 copy_string(lsm.session.name, handle->session_name,
997 sizeof(lsm.session.name));
998
999 return ask_sessiond(&lsm, NULL);
1000 }
1001
1002 /*
1003 * Enable channel per domain
1004 * Returns size of returned session payload data or a negative error code.
1005 */
1006 int lttng_enable_channel(struct lttng_handle *handle,
1007 struct lttng_channel *chan)
1008 {
1009 struct lttcomm_session_msg lsm;
1010
1011 /*
1012 * NULL arguments are forbidden. No default values.
1013 */
1014 if (handle == NULL || chan == NULL) {
1015 return -LTTNG_ERR_INVALID;
1016 }
1017
1018 memset(&lsm, 0, sizeof(lsm));
1019
1020 memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
1021
1022 lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
1023
1024 copy_lttng_domain(&lsm.domain, &handle->domain);
1025
1026 copy_string(lsm.session.name, handle->session_name,
1027 sizeof(lsm.session.name));
1028
1029 return ask_sessiond(&lsm, NULL);
1030 }
1031
1032 /*
1033 * All tracing will be stopped for registered events of the channel.
1034 * Returns size of returned session payload data or a negative error code.
1035 */
1036 int lttng_disable_channel(struct lttng_handle *handle, const char *name)
1037 {
1038 struct lttcomm_session_msg lsm;
1039
1040 /* Safety check. Both are mandatory */
1041 if (handle == NULL || name == NULL) {
1042 return -LTTNG_ERR_INVALID;
1043 }
1044
1045 memset(&lsm, 0, sizeof(lsm));
1046
1047 lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
1048
1049 copy_string(lsm.u.disable.channel_name, name,
1050 sizeof(lsm.u.disable.channel_name));
1051
1052 copy_lttng_domain(&lsm.domain, &handle->domain);
1053
1054 copy_string(lsm.session.name, handle->session_name,
1055 sizeof(lsm.session.name));
1056
1057 return ask_sessiond(&lsm, NULL);
1058 }
1059
1060 /*
1061 * Lists all available tracepoints of domain.
1062 * Sets the contents of the events array.
1063 * Returns the number of lttng_event entries in events;
1064 * on error, returns a negative value.
1065 */
1066 int lttng_list_tracepoints(struct lttng_handle *handle,
1067 struct lttng_event **events)
1068 {
1069 int ret;
1070 struct lttcomm_session_msg lsm;
1071
1072 if (handle == NULL) {
1073 return -LTTNG_ERR_INVALID;
1074 }
1075
1076 lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
1077 copy_lttng_domain(&lsm.domain, &handle->domain);
1078
1079 ret = ask_sessiond(&lsm, (void **) events);
1080 if (ret < 0) {
1081 return ret;
1082 }
1083
1084 return ret / sizeof(struct lttng_event);
1085 }
1086
1087 /*
1088 * Lists all available tracepoint fields of domain.
1089 * Sets the contents of the event field array.
1090 * Returns the number of lttng_event_field entries in events;
1091 * on error, returns a negative value.
1092 */
1093 int lttng_list_tracepoint_fields(struct lttng_handle *handle,
1094 struct lttng_event_field **fields)
1095 {
1096 int ret;
1097 struct lttcomm_session_msg lsm;
1098
1099 if (handle == NULL) {
1100 return -LTTNG_ERR_INVALID;
1101 }
1102
1103 lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
1104 copy_lttng_domain(&lsm.domain, &handle->domain);
1105
1106 ret = ask_sessiond(&lsm, (void **) fields);
1107 if (ret < 0) {
1108 return ret;
1109 }
1110
1111 return ret / sizeof(struct lttng_event_field);
1112 }
1113
1114 /*
1115 * Returns a human readable string describing
1116 * the error code (a negative value).
1117 */
1118 const char *lttng_strerror(int code)
1119 {
1120 return error_get_str(code);
1121 }
1122
1123 /*
1124 * Create a brand new session using name and url for destination.
1125 *
1126 * Returns LTTNG_OK on success or a negative error code.
1127 */
1128 int lttng_create_session(const char *name, const char *url)
1129 {
1130 ssize_t size;
1131 struct lttcomm_session_msg lsm;
1132 struct lttng_uri *uris = NULL;
1133
1134 if (name == NULL) {
1135 return -LTTNG_ERR_INVALID;
1136 }
1137
1138 memset(&lsm, 0, sizeof(lsm));
1139
1140 lsm.cmd_type = LTTNG_CREATE_SESSION;
1141 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1142
1143 /* There should never be a data URL */
1144 size = parse_str_urls_to_uri(url, NULL, &uris);
1145 if (size < 0) {
1146 return -LTTNG_ERR_INVALID;
1147 }
1148
1149 lsm.u.uri.size = size;
1150
1151 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1152 NULL);
1153 }
1154
1155 /*
1156 * Destroy session using name.
1157 * Returns size of returned session payload data or a negative error code.
1158 */
1159 int lttng_destroy_session(const char *session_name)
1160 {
1161 struct lttcomm_session_msg lsm;
1162
1163 if (session_name == NULL) {
1164 return -LTTNG_ERR_INVALID;
1165 }
1166
1167 lsm.cmd_type = LTTNG_DESTROY_SESSION;
1168
1169 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1170
1171 return ask_sessiond(&lsm, NULL);
1172 }
1173
1174 /*
1175 * Ask the session daemon for all available sessions.
1176 * Sets the contents of the sessions array.
1177 * Returns the number of lttng_session entries in sessions;
1178 * on error, returns a negative value.
1179 */
1180 int lttng_list_sessions(struct lttng_session **sessions)
1181 {
1182 int ret;
1183 struct lttcomm_session_msg lsm;
1184
1185 lsm.cmd_type = LTTNG_LIST_SESSIONS;
1186 ret = ask_sessiond(&lsm, (void**) sessions);
1187 if (ret < 0) {
1188 return ret;
1189 }
1190
1191 return ret / sizeof(struct lttng_session);
1192 }
1193
1194 /*
1195 * Ask the session daemon for all available domains of a session.
1196 * Sets the contents of the domains array.
1197 * Returns the number of lttng_domain entries in domains;
1198 * on error, returns a negative value.
1199 */
1200 int lttng_list_domains(const char *session_name,
1201 struct lttng_domain **domains)
1202 {
1203 int ret;
1204 struct lttcomm_session_msg lsm;
1205
1206 if (session_name == NULL) {
1207 return -LTTNG_ERR_INVALID;
1208 }
1209
1210 lsm.cmd_type = LTTNG_LIST_DOMAINS;
1211
1212 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1213
1214 ret = ask_sessiond(&lsm, (void**) domains);
1215 if (ret < 0) {
1216 return ret;
1217 }
1218
1219 return ret / sizeof(struct lttng_domain);
1220 }
1221
1222 /*
1223 * Ask the session daemon for all available channels of a session.
1224 * Sets the contents of the channels array.
1225 * Returns the number of lttng_channel entries in channels;
1226 * on error, returns a negative value.
1227 */
1228 int lttng_list_channels(struct lttng_handle *handle,
1229 struct lttng_channel **channels)
1230 {
1231 int ret;
1232 struct lttcomm_session_msg lsm;
1233
1234 if (handle == NULL) {
1235 return -LTTNG_ERR_INVALID;
1236 }
1237
1238 lsm.cmd_type = LTTNG_LIST_CHANNELS;
1239 copy_string(lsm.session.name, handle->session_name,
1240 sizeof(lsm.session.name));
1241
1242 copy_lttng_domain(&lsm.domain, &handle->domain);
1243
1244 ret = ask_sessiond(&lsm, (void**) channels);
1245 if (ret < 0) {
1246 return ret;
1247 }
1248
1249 return ret / sizeof(struct lttng_channel);
1250 }
1251
1252 /*
1253 * Ask the session daemon for all available events of a session channel.
1254 * Sets the contents of the events array.
1255 * Returns the number of lttng_event entries in events;
1256 * on error, returns a negative value.
1257 */
1258 int lttng_list_events(struct lttng_handle *handle,
1259 const char *channel_name, struct lttng_event **events)
1260 {
1261 int ret;
1262 struct lttcomm_session_msg lsm;
1263
1264 /* Safety check. An handle and channel name are mandatory */
1265 if (handle == NULL || channel_name == NULL) {
1266 return -LTTNG_ERR_INVALID;
1267 }
1268
1269 lsm.cmd_type = LTTNG_LIST_EVENTS;
1270 copy_string(lsm.session.name, handle->session_name,
1271 sizeof(lsm.session.name));
1272 copy_string(lsm.u.list.channel_name, channel_name,
1273 sizeof(lsm.u.list.channel_name));
1274
1275 copy_lttng_domain(&lsm.domain, &handle->domain);
1276
1277 ret = ask_sessiond(&lsm, (void**) events);
1278 if (ret < 0) {
1279 return ret;
1280 }
1281
1282 return ret / sizeof(struct lttng_event);
1283 }
1284
1285 /*
1286 * Sets the tracing_group variable with name.
1287 * This function allocates memory pointed to by tracing_group.
1288 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1289 */
1290 int lttng_set_tracing_group(const char *name)
1291 {
1292 if (name == NULL) {
1293 return -LTTNG_ERR_INVALID;
1294 }
1295
1296 if (asprintf(&tracing_group, "%s", name) < 0) {
1297 return -LTTNG_ERR_FATAL;
1298 }
1299
1300 return 0;
1301 }
1302
1303 /*
1304 * Returns size of returned session payload data or a negative error code.
1305 */
1306 int lttng_calibrate(struct lttng_handle *handle,
1307 struct lttng_calibrate *calibrate)
1308 {
1309 struct lttcomm_session_msg lsm;
1310
1311 /* Safety check. NULL pointer are forbidden */
1312 if (handle == NULL || calibrate == NULL) {
1313 return -LTTNG_ERR_INVALID;
1314 }
1315
1316 lsm.cmd_type = LTTNG_CALIBRATE;
1317 copy_lttng_domain(&lsm.domain, &handle->domain);
1318
1319 memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
1320
1321 return ask_sessiond(&lsm, NULL);
1322 }
1323
1324 /*
1325 * Set default channel attributes.
1326 * If either or both of the arguments are null, attr content is zeroe'd.
1327 */
1328 void lttng_channel_set_default_attr(struct lttng_domain *domain,
1329 struct lttng_channel_attr *attr)
1330 {
1331 /* Safety check */
1332 if (attr == NULL || domain == NULL) {
1333 return;
1334 }
1335
1336 memset(attr, 0, sizeof(struct lttng_channel_attr));
1337
1338 switch (domain->type) {
1339 case LTTNG_DOMAIN_KERNEL:
1340 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1341 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1342 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1343
1344 attr->subbuf_size = default_get_kernel_channel_subbuf_size();
1345 attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1346 attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1347 break;
1348 case LTTNG_DOMAIN_UST:
1349 #if 0
1350 case LTTNG_DOMAIN_UST_EXEC_NAME:
1351 case LTTNG_DOMAIN_UST_PID:
1352 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1353 #endif
1354 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1355 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1356 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1357
1358 attr->subbuf_size = default_get_ust_channel_subbuf_size();
1359 attr->num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
1360 attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
1361 break;
1362 default:
1363 /* Default behavior: leave set to 0. */
1364 break;
1365 }
1366 }
1367
1368 /*
1369 * Check if session daemon is alive.
1370 *
1371 * Return 1 if alive or 0 if not.
1372 * On error returns a negative value.
1373 */
1374 int lttng_session_daemon_alive(void)
1375 {
1376 int ret;
1377
1378 ret = set_session_daemon_path();
1379 if (ret < 0) {
1380 /* Error */
1381 return ret;
1382 }
1383
1384 if (strlen(sessiond_sock_path) == 0) {
1385 /*
1386 * No socket path set. Weird error which means the constructor was not
1387 * called.
1388 */
1389 assert(0);
1390 }
1391
1392 ret = try_connect_sessiond(sessiond_sock_path);
1393 if (ret < 0) {
1394 /* Not alive */
1395 return 0;
1396 }
1397
1398 /* Is alive */
1399 return 1;
1400 }
1401
1402 /*
1403 * Set URL for a consumer for a session and domain.
1404 *
1405 * Return 0 on success, else a negative value.
1406 */
1407 int lttng_set_consumer_url(struct lttng_handle *handle,
1408 const char *control_url, const char *data_url)
1409 {
1410 ssize_t size;
1411 struct lttcomm_session_msg lsm;
1412 struct lttng_uri *uris = NULL;
1413
1414 if (handle == NULL || (control_url == NULL && data_url == NULL)) {
1415 return -LTTNG_ERR_INVALID;
1416 }
1417
1418 memset(&lsm, 0, sizeof(lsm));
1419
1420 lsm.cmd_type = LTTNG_SET_CONSUMER_URI;
1421
1422 copy_string(lsm.session.name, handle->session_name,
1423 sizeof(lsm.session.name));
1424 copy_lttng_domain(&lsm.domain, &handle->domain);
1425
1426 size = parse_str_urls_to_uri(control_url, data_url, &uris);
1427 if (size < 0) {
1428 return -LTTNG_ERR_INVALID;
1429 }
1430
1431 lsm.u.uri.size = size;
1432
1433 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1434 NULL);
1435 }
1436
1437 /*
1438 * Enable consumer for a session and domain.
1439 *
1440 * Return 0 on success, else a negative value.
1441 */
1442 int lttng_enable_consumer(struct lttng_handle *handle)
1443 {
1444 struct lttcomm_session_msg lsm;
1445
1446 if (handle == NULL) {
1447 return -LTTNG_ERR_INVALID;
1448 }
1449
1450 lsm.cmd_type = LTTNG_ENABLE_CONSUMER;
1451
1452 copy_string(lsm.session.name, handle->session_name,
1453 sizeof(lsm.session.name));
1454 copy_lttng_domain(&lsm.domain, &handle->domain);
1455
1456 return ask_sessiond(&lsm, NULL);
1457 }
1458
1459 /*
1460 * Disable consumer for a session and domain.
1461 *
1462 * Return 0 on success, else a negative value.
1463 */
1464 int lttng_disable_consumer(struct lttng_handle *handle)
1465 {
1466 struct lttcomm_session_msg lsm;
1467
1468 if (handle == NULL) {
1469 return -LTTNG_ERR_INVALID;
1470 }
1471
1472 lsm.cmd_type = LTTNG_DISABLE_CONSUMER;
1473
1474 copy_string(lsm.session.name, handle->session_name,
1475 sizeof(lsm.session.name));
1476 copy_lttng_domain(&lsm.domain, &handle->domain);
1477
1478 return ask_sessiond(&lsm, NULL);
1479 }
1480
1481 /*
1482 * Set health socket path by putting it in the global health_sock_path
1483 * variable.
1484 *
1485 * Returns 0 on success or assert(0) on ENOMEM.
1486 */
1487 static int set_health_socket_path(void)
1488 {
1489 int ret;
1490 int in_tgroup = 0; /* In tracing group */
1491 uid_t uid;
1492 const char *home;
1493
1494 uid = getuid();
1495
1496 if (uid != 0) {
1497 /* Are we in the tracing group ? */
1498 in_tgroup = check_tracing_group(tracing_group);
1499 }
1500
1501 if ((uid == 0) || in_tgroup) {
1502 copy_string(health_sock_path, DEFAULT_GLOBAL_HEALTH_UNIX_SOCK,
1503 sizeof(health_sock_path));
1504 }
1505
1506 if (uid != 0) {
1507 /*
1508 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
1509 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
1510 */
1511 home = getenv("HOME");
1512 if (home == NULL) {
1513 /* Fallback in /tmp .. */
1514 home = "/tmp";
1515 }
1516
1517 ret = snprintf(health_sock_path, sizeof(health_sock_path),
1518 DEFAULT_HOME_HEALTH_UNIX_SOCK, home);
1519 if ((ret < 0) || (ret >= sizeof(health_sock_path))) {
1520 /* ENOMEM at this point... just kill the control lib. */
1521 assert(0);
1522 }
1523 }
1524
1525 return 0;
1526 }
1527
1528 /*
1529 * Check session daemon health for a specific health component.
1530 *
1531 * Return 0 if health is OK or else 1 if BAD.
1532 *
1533 * Any other negative value is a lttng error code which can be translated with
1534 * lttng_strerror().
1535 */
1536 int lttng_health_check(enum lttng_health_component c)
1537 {
1538 int sock, ret;
1539 struct lttcomm_health_msg msg;
1540 struct lttcomm_health_data reply;
1541
1542 /* Connect to the sesssion daemon */
1543 sock = lttcomm_connect_unix_sock(health_sock_path);
1544 if (sock < 0) {
1545 ret = -LTTNG_ERR_NO_SESSIOND;
1546 goto error;
1547 }
1548
1549 msg.cmd = LTTNG_HEALTH_CHECK;
1550 msg.component = c;
1551
1552 ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
1553 if (ret < 0) {
1554 ret = -LTTNG_ERR_FATAL;
1555 goto close_error;
1556 }
1557
1558 ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
1559 if (ret < 0) {
1560 ret = -LTTNG_ERR_FATAL;
1561 goto close_error;
1562 }
1563
1564 ret = reply.ret_code;
1565
1566 close_error:
1567 close(sock);
1568
1569 error:
1570 return ret;
1571 }
1572
1573 /*
1574 * This is an extension of create session that is ONLY and SHOULD only be used
1575 * by the lttng command line program. It exists to avoid using URI parsing in
1576 * the lttng client.
1577 *
1578 * We need the date and time for the trace path subdirectory for the case where
1579 * the user does NOT define one using either -o or -U. Using the normal
1580 * lttng_create_session API call, we have no clue on the session daemon side if
1581 * the URL was generated automatically by the client or define by the user.
1582 *
1583 * So this function "wrapper" is hidden from the public API, takes the datetime
1584 * string and appends it if necessary to the URI subdirectory before sending it
1585 * to the session daemon.
1586 *
1587 * With this extra function, the lttng_create_session call behavior is not
1588 * changed and the timestamp is appended to the URI on the session daemon side
1589 * if necessary.
1590 */
1591 int _lttng_create_session_ext(const char *name, const char *url,
1592 const char *datetime)
1593 {
1594 int ret;
1595 ssize_t size;
1596 struct lttcomm_session_msg lsm;
1597 struct lttng_uri *uris = NULL;
1598
1599 if (name == NULL || datetime == NULL) {
1600 return -LTTNG_ERR_INVALID;
1601 }
1602
1603 memset(&lsm, 0, sizeof(lsm));
1604
1605 lsm.cmd_type = LTTNG_CREATE_SESSION;
1606 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1607
1608 /* There should never be a data URL */
1609 size = parse_str_urls_to_uri(url, NULL, &uris);
1610 if (size < 0) {
1611 return -LTTNG_ERR_INVALID;
1612 }
1613
1614 lsm.u.uri.size = size;
1615
1616 if (size > 0 && uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
1617 ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s-%s", name,
1618 datetime);
1619 if (ret < 0) {
1620 PERROR("snprintf uri subdir");
1621 return -LTTNG_ERR_FATAL;
1622 }
1623 }
1624
1625 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1626 NULL);
1627 }
1628
1629 /*
1630 * For a given session name, this call checks if the data is ready to be read
1631 * or is still being extracted by the consumer(s) hence not ready to be used by
1632 * any readers.
1633 */
1634 int lttng_data_pending(const char *session_name)
1635 {
1636 int ret;
1637 struct lttcomm_session_msg lsm;
1638
1639 if (session_name == NULL) {
1640 return -LTTNG_ERR_INVALID;
1641 }
1642
1643 lsm.cmd_type = LTTNG_DATA_PENDING;
1644
1645 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1646
1647 ret = ask_sessiond(&lsm, NULL);
1648
1649 /*
1650 * The ask_sessiond function negate the return code if it's not LTTNG_OK so
1651 * getting -1 means that the reply ret_code was 1 thus meaning that the
1652 * data is available. Yes it is hackish but for now this is the only way.
1653 */
1654 if (ret == -1) {
1655 ret = 1;
1656 }
1657
1658 return ret;
1659 }
1660
1661 /*
1662 * lib constructor
1663 */
1664 static void __attribute__((constructor)) init()
1665 {
1666 /* Set default session group */
1667 lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
1668 /* Set socket for health check */
1669 (void) set_health_socket_path();
1670 }
1671
1672 /*
1673 * lib destructor
1674 */
1675 static void __attribute__((destructor)) lttng_ctl_exit()
1676 {
1677 free(tracing_group);
1678 }
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