Pass lttng_event struct to the set_filter API call
[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 *
832 * Return negative error value on error.
833 * Return size of returned session payload data if OK.
834 */
835 int lttng_set_event_filter(struct lttng_handle *handle,
836 struct lttng_event *event, 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 if (event) {
931 memcpy(&lsm.u.enable.event, event, sizeof(lsm.u.enable.event));
932 }
933
934 lsm.u.filter.bytecode_len = sizeof(ctx->bytecode->b)
935 + bytecode_get_len(&ctx->bytecode->b);
936
937 copy_lttng_domain(&lsm.domain, &handle->domain);
938
939 copy_string(lsm.session.name, handle->session_name,
940 sizeof(lsm.session.name));
941
942 ret = ask_sessiond_varlen(&lsm, &ctx->bytecode->b,
943 lsm.u.filter.bytecode_len, NULL);
944
945 filter_bytecode_free(ctx);
946 filter_ir_free(ctx);
947 filter_parser_ctx_free(ctx);
948 if (fclose(fmem) != 0) {
949 perror("fclose");
950 }
951 return ret;
952
953 parse_error:
954 filter_bytecode_free(ctx);
955 filter_ir_free(ctx);
956 filter_parser_ctx_free(ctx);
957 alloc_error:
958 if (fclose(fmem) != 0) {
959 perror("fclose");
960 }
961 return ret;
962 }
963
964 /*
965 * Disable event(s) of a channel and domain.
966 * If no event name is specified, all events are disabled.
967 * If no channel name is specified, the default 'channel0' is used.
968 * Returns size of returned session payload data or a negative error code.
969 */
970 int lttng_disable_event(struct lttng_handle *handle, const char *name,
971 const char *channel_name)
972 {
973 struct lttcomm_session_msg lsm;
974
975 if (handle == NULL) {
976 return -LTTNG_ERR_INVALID;
977 }
978
979 memset(&lsm, 0, sizeof(lsm));
980
981 if (channel_name) {
982 copy_string(lsm.u.disable.channel_name, channel_name,
983 sizeof(lsm.u.disable.channel_name));
984 } else {
985 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
986 sizeof(lsm.u.disable.channel_name));
987 }
988
989 copy_lttng_domain(&lsm.domain, &handle->domain);
990
991 if (name != NULL) {
992 copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
993 lsm.cmd_type = LTTNG_DISABLE_EVENT;
994 } else {
995 lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
996 }
997
998 copy_string(lsm.session.name, handle->session_name,
999 sizeof(lsm.session.name));
1000
1001 return ask_sessiond(&lsm, NULL);
1002 }
1003
1004 /*
1005 * Enable channel per domain
1006 * Returns size of returned session payload data or a negative error code.
1007 */
1008 int lttng_enable_channel(struct lttng_handle *handle,
1009 struct lttng_channel *chan)
1010 {
1011 struct lttcomm_session_msg lsm;
1012
1013 /*
1014 * NULL arguments are forbidden. No default values.
1015 */
1016 if (handle == NULL || chan == NULL) {
1017 return -LTTNG_ERR_INVALID;
1018 }
1019
1020 memset(&lsm, 0, sizeof(lsm));
1021
1022 memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
1023
1024 lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
1025
1026 copy_lttng_domain(&lsm.domain, &handle->domain);
1027
1028 copy_string(lsm.session.name, handle->session_name,
1029 sizeof(lsm.session.name));
1030
1031 return ask_sessiond(&lsm, NULL);
1032 }
1033
1034 /*
1035 * All tracing will be stopped for registered events of the channel.
1036 * Returns size of returned session payload data or a negative error code.
1037 */
1038 int lttng_disable_channel(struct lttng_handle *handle, const char *name)
1039 {
1040 struct lttcomm_session_msg lsm;
1041
1042 /* Safety check. Both are mandatory */
1043 if (handle == NULL || name == NULL) {
1044 return -LTTNG_ERR_INVALID;
1045 }
1046
1047 memset(&lsm, 0, sizeof(lsm));
1048
1049 lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
1050
1051 copy_string(lsm.u.disable.channel_name, name,
1052 sizeof(lsm.u.disable.channel_name));
1053
1054 copy_lttng_domain(&lsm.domain, &handle->domain);
1055
1056 copy_string(lsm.session.name, handle->session_name,
1057 sizeof(lsm.session.name));
1058
1059 return ask_sessiond(&lsm, NULL);
1060 }
1061
1062 /*
1063 * Lists all available tracepoints of domain.
1064 * Sets the contents of the events array.
1065 * Returns the number of lttng_event entries in events;
1066 * on error, returns a negative value.
1067 */
1068 int lttng_list_tracepoints(struct lttng_handle *handle,
1069 struct lttng_event **events)
1070 {
1071 int ret;
1072 struct lttcomm_session_msg lsm;
1073
1074 if (handle == NULL) {
1075 return -LTTNG_ERR_INVALID;
1076 }
1077
1078 lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
1079 copy_lttng_domain(&lsm.domain, &handle->domain);
1080
1081 ret = ask_sessiond(&lsm, (void **) events);
1082 if (ret < 0) {
1083 return ret;
1084 }
1085
1086 return ret / sizeof(struct lttng_event);
1087 }
1088
1089 /*
1090 * Lists all available tracepoint fields of domain.
1091 * Sets the contents of the event field array.
1092 * Returns the number of lttng_event_field entries in events;
1093 * on error, returns a negative value.
1094 */
1095 int lttng_list_tracepoint_fields(struct lttng_handle *handle,
1096 struct lttng_event_field **fields)
1097 {
1098 int ret;
1099 struct lttcomm_session_msg lsm;
1100
1101 if (handle == NULL) {
1102 return -LTTNG_ERR_INVALID;
1103 }
1104
1105 lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
1106 copy_lttng_domain(&lsm.domain, &handle->domain);
1107
1108 ret = ask_sessiond(&lsm, (void **) fields);
1109 if (ret < 0) {
1110 return ret;
1111 }
1112
1113 return ret / sizeof(struct lttng_event_field);
1114 }
1115
1116 /*
1117 * Returns a human readable string describing
1118 * the error code (a negative value).
1119 */
1120 const char *lttng_strerror(int code)
1121 {
1122 return error_get_str(code);
1123 }
1124
1125 /*
1126 * Create a brand new session using name and url for destination.
1127 *
1128 * Returns LTTNG_OK on success or a negative error code.
1129 */
1130 int lttng_create_session(const char *name, const char *url)
1131 {
1132 ssize_t size;
1133 struct lttcomm_session_msg lsm;
1134 struct lttng_uri *uris = NULL;
1135
1136 if (name == NULL) {
1137 return -LTTNG_ERR_INVALID;
1138 }
1139
1140 memset(&lsm, 0, sizeof(lsm));
1141
1142 lsm.cmd_type = LTTNG_CREATE_SESSION;
1143 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1144
1145 /* There should never be a data URL */
1146 size = parse_str_urls_to_uri(url, NULL, &uris);
1147 if (size < 0) {
1148 return -LTTNG_ERR_INVALID;
1149 }
1150
1151 lsm.u.uri.size = size;
1152
1153 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1154 NULL);
1155 }
1156
1157 /*
1158 * Destroy session using name.
1159 * Returns size of returned session payload data or a negative error code.
1160 */
1161 int lttng_destroy_session(const char *session_name)
1162 {
1163 struct lttcomm_session_msg lsm;
1164
1165 if (session_name == NULL) {
1166 return -LTTNG_ERR_INVALID;
1167 }
1168
1169 lsm.cmd_type = LTTNG_DESTROY_SESSION;
1170
1171 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1172
1173 return ask_sessiond(&lsm, NULL);
1174 }
1175
1176 /*
1177 * Ask the session daemon for all available sessions.
1178 * Sets the contents of the sessions array.
1179 * Returns the number of lttng_session entries in sessions;
1180 * on error, returns a negative value.
1181 */
1182 int lttng_list_sessions(struct lttng_session **sessions)
1183 {
1184 int ret;
1185 struct lttcomm_session_msg lsm;
1186
1187 lsm.cmd_type = LTTNG_LIST_SESSIONS;
1188 ret = ask_sessiond(&lsm, (void**) sessions);
1189 if (ret < 0) {
1190 return ret;
1191 }
1192
1193 return ret / sizeof(struct lttng_session);
1194 }
1195
1196 /*
1197 * Ask the session daemon for all available domains of a session.
1198 * Sets the contents of the domains array.
1199 * Returns the number of lttng_domain entries in domains;
1200 * on error, returns a negative value.
1201 */
1202 int lttng_list_domains(const char *session_name,
1203 struct lttng_domain **domains)
1204 {
1205 int ret;
1206 struct lttcomm_session_msg lsm;
1207
1208 if (session_name == NULL) {
1209 return -LTTNG_ERR_INVALID;
1210 }
1211
1212 lsm.cmd_type = LTTNG_LIST_DOMAINS;
1213
1214 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1215
1216 ret = ask_sessiond(&lsm, (void**) domains);
1217 if (ret < 0) {
1218 return ret;
1219 }
1220
1221 return ret / sizeof(struct lttng_domain);
1222 }
1223
1224 /*
1225 * Ask the session daemon for all available channels of a session.
1226 * Sets the contents of the channels array.
1227 * Returns the number of lttng_channel entries in channels;
1228 * on error, returns a negative value.
1229 */
1230 int lttng_list_channels(struct lttng_handle *handle,
1231 struct lttng_channel **channels)
1232 {
1233 int ret;
1234 struct lttcomm_session_msg lsm;
1235
1236 if (handle == NULL) {
1237 return -LTTNG_ERR_INVALID;
1238 }
1239
1240 lsm.cmd_type = LTTNG_LIST_CHANNELS;
1241 copy_string(lsm.session.name, handle->session_name,
1242 sizeof(lsm.session.name));
1243
1244 copy_lttng_domain(&lsm.domain, &handle->domain);
1245
1246 ret = ask_sessiond(&lsm, (void**) channels);
1247 if (ret < 0) {
1248 return ret;
1249 }
1250
1251 return ret / sizeof(struct lttng_channel);
1252 }
1253
1254 /*
1255 * Ask the session daemon for all available events of a session channel.
1256 * Sets the contents of the events array.
1257 * Returns the number of lttng_event entries in events;
1258 * on error, returns a negative value.
1259 */
1260 int lttng_list_events(struct lttng_handle *handle,
1261 const char *channel_name, struct lttng_event **events)
1262 {
1263 int ret;
1264 struct lttcomm_session_msg lsm;
1265
1266 /* Safety check. An handle and channel name are mandatory */
1267 if (handle == NULL || channel_name == NULL) {
1268 return -LTTNG_ERR_INVALID;
1269 }
1270
1271 lsm.cmd_type = LTTNG_LIST_EVENTS;
1272 copy_string(lsm.session.name, handle->session_name,
1273 sizeof(lsm.session.name));
1274 copy_string(lsm.u.list.channel_name, channel_name,
1275 sizeof(lsm.u.list.channel_name));
1276
1277 copy_lttng_domain(&lsm.domain, &handle->domain);
1278
1279 ret = ask_sessiond(&lsm, (void**) events);
1280 if (ret < 0) {
1281 return ret;
1282 }
1283
1284 return ret / sizeof(struct lttng_event);
1285 }
1286
1287 /*
1288 * Sets the tracing_group variable with name.
1289 * This function allocates memory pointed to by tracing_group.
1290 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1291 */
1292 int lttng_set_tracing_group(const char *name)
1293 {
1294 if (name == NULL) {
1295 return -LTTNG_ERR_INVALID;
1296 }
1297
1298 if (asprintf(&tracing_group, "%s", name) < 0) {
1299 return -LTTNG_ERR_FATAL;
1300 }
1301
1302 return 0;
1303 }
1304
1305 /*
1306 * Returns size of returned session payload data or a negative error code.
1307 */
1308 int lttng_calibrate(struct lttng_handle *handle,
1309 struct lttng_calibrate *calibrate)
1310 {
1311 struct lttcomm_session_msg lsm;
1312
1313 /* Safety check. NULL pointer are forbidden */
1314 if (handle == NULL || calibrate == NULL) {
1315 return -LTTNG_ERR_INVALID;
1316 }
1317
1318 lsm.cmd_type = LTTNG_CALIBRATE;
1319 copy_lttng_domain(&lsm.domain, &handle->domain);
1320
1321 memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
1322
1323 return ask_sessiond(&lsm, NULL);
1324 }
1325
1326 /*
1327 * Set default channel attributes.
1328 * If either or both of the arguments are null, attr content is zeroe'd.
1329 */
1330 void lttng_channel_set_default_attr(struct lttng_domain *domain,
1331 struct lttng_channel_attr *attr)
1332 {
1333 /* Safety check */
1334 if (attr == NULL || domain == NULL) {
1335 return;
1336 }
1337
1338 memset(attr, 0, sizeof(struct lttng_channel_attr));
1339
1340 switch (domain->type) {
1341 case LTTNG_DOMAIN_KERNEL:
1342 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1343 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1344 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1345
1346 attr->subbuf_size = default_get_kernel_channel_subbuf_size();
1347 attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1348 attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1349 break;
1350 case LTTNG_DOMAIN_UST:
1351 #if 0
1352 case LTTNG_DOMAIN_UST_EXEC_NAME:
1353 case LTTNG_DOMAIN_UST_PID:
1354 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1355 #endif
1356 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1357 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1358 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1359
1360 attr->subbuf_size = default_get_ust_channel_subbuf_size();
1361 attr->num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
1362 attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
1363 break;
1364 default:
1365 /* Default behavior: leave set to 0. */
1366 break;
1367 }
1368 }
1369
1370 /*
1371 * Check if session daemon is alive.
1372 *
1373 * Return 1 if alive or 0 if not.
1374 * On error returns a negative value.
1375 */
1376 int lttng_session_daemon_alive(void)
1377 {
1378 int ret;
1379
1380 ret = set_session_daemon_path();
1381 if (ret < 0) {
1382 /* Error */
1383 return ret;
1384 }
1385
1386 if (strlen(sessiond_sock_path) == 0) {
1387 /*
1388 * No socket path set. Weird error which means the constructor was not
1389 * called.
1390 */
1391 assert(0);
1392 }
1393
1394 ret = try_connect_sessiond(sessiond_sock_path);
1395 if (ret < 0) {
1396 /* Not alive */
1397 return 0;
1398 }
1399
1400 /* Is alive */
1401 return 1;
1402 }
1403
1404 /*
1405 * Set URL for a consumer for a session and domain.
1406 *
1407 * Return 0 on success, else a negative value.
1408 */
1409 int lttng_set_consumer_url(struct lttng_handle *handle,
1410 const char *control_url, const char *data_url)
1411 {
1412 ssize_t size;
1413 struct lttcomm_session_msg lsm;
1414 struct lttng_uri *uris = NULL;
1415
1416 if (handle == NULL || (control_url == NULL && data_url == NULL)) {
1417 return -LTTNG_ERR_INVALID;
1418 }
1419
1420 memset(&lsm, 0, sizeof(lsm));
1421
1422 lsm.cmd_type = LTTNG_SET_CONSUMER_URI;
1423
1424 copy_string(lsm.session.name, handle->session_name,
1425 sizeof(lsm.session.name));
1426 copy_lttng_domain(&lsm.domain, &handle->domain);
1427
1428 size = parse_str_urls_to_uri(control_url, data_url, &uris);
1429 if (size < 0) {
1430 return -LTTNG_ERR_INVALID;
1431 }
1432
1433 lsm.u.uri.size = size;
1434
1435 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1436 NULL);
1437 }
1438
1439 /*
1440 * Enable consumer for a session and domain.
1441 *
1442 * Return 0 on success, else a negative value.
1443 */
1444 int lttng_enable_consumer(struct lttng_handle *handle)
1445 {
1446 struct lttcomm_session_msg lsm;
1447
1448 if (handle == NULL) {
1449 return -LTTNG_ERR_INVALID;
1450 }
1451
1452 lsm.cmd_type = LTTNG_ENABLE_CONSUMER;
1453
1454 copy_string(lsm.session.name, handle->session_name,
1455 sizeof(lsm.session.name));
1456 copy_lttng_domain(&lsm.domain, &handle->domain);
1457
1458 return ask_sessiond(&lsm, NULL);
1459 }
1460
1461 /*
1462 * Disable consumer for a session and domain.
1463 *
1464 * Return 0 on success, else a negative value.
1465 */
1466 int lttng_disable_consumer(struct lttng_handle *handle)
1467 {
1468 struct lttcomm_session_msg lsm;
1469
1470 if (handle == NULL) {
1471 return -LTTNG_ERR_INVALID;
1472 }
1473
1474 lsm.cmd_type = LTTNG_DISABLE_CONSUMER;
1475
1476 copy_string(lsm.session.name, handle->session_name,
1477 sizeof(lsm.session.name));
1478 copy_lttng_domain(&lsm.domain, &handle->domain);
1479
1480 return ask_sessiond(&lsm, NULL);
1481 }
1482
1483 /*
1484 * Set health socket path by putting it in the global health_sock_path
1485 * variable.
1486 *
1487 * Returns 0 on success or assert(0) on ENOMEM.
1488 */
1489 static int set_health_socket_path(void)
1490 {
1491 int ret;
1492 int in_tgroup = 0; /* In tracing group */
1493 uid_t uid;
1494 const char *home;
1495
1496 uid = getuid();
1497
1498 if (uid != 0) {
1499 /* Are we in the tracing group ? */
1500 in_tgroup = check_tracing_group(tracing_group);
1501 }
1502
1503 if ((uid == 0) || in_tgroup) {
1504 copy_string(health_sock_path, DEFAULT_GLOBAL_HEALTH_UNIX_SOCK,
1505 sizeof(health_sock_path));
1506 }
1507
1508 if (uid != 0) {
1509 /*
1510 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
1511 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
1512 */
1513 home = getenv("HOME");
1514 if (home == NULL) {
1515 /* Fallback in /tmp .. */
1516 home = "/tmp";
1517 }
1518
1519 ret = snprintf(health_sock_path, sizeof(health_sock_path),
1520 DEFAULT_HOME_HEALTH_UNIX_SOCK, home);
1521 if ((ret < 0) || (ret >= sizeof(health_sock_path))) {
1522 /* ENOMEM at this point... just kill the control lib. */
1523 assert(0);
1524 }
1525 }
1526
1527 return 0;
1528 }
1529
1530 /*
1531 * Check session daemon health for a specific health component.
1532 *
1533 * Return 0 if health is OK or else 1 if BAD.
1534 *
1535 * Any other negative value is a lttng error code which can be translated with
1536 * lttng_strerror().
1537 */
1538 int lttng_health_check(enum lttng_health_component c)
1539 {
1540 int sock, ret;
1541 struct lttcomm_health_msg msg;
1542 struct lttcomm_health_data reply;
1543
1544 /* Connect to the sesssion daemon */
1545 sock = lttcomm_connect_unix_sock(health_sock_path);
1546 if (sock < 0) {
1547 ret = -LTTNG_ERR_NO_SESSIOND;
1548 goto error;
1549 }
1550
1551 msg.cmd = LTTNG_HEALTH_CHECK;
1552 msg.component = c;
1553
1554 ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
1555 if (ret < 0) {
1556 ret = -LTTNG_ERR_FATAL;
1557 goto close_error;
1558 }
1559
1560 ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
1561 if (ret < 0) {
1562 ret = -LTTNG_ERR_FATAL;
1563 goto close_error;
1564 }
1565
1566 ret = reply.ret_code;
1567
1568 close_error:
1569 close(sock);
1570
1571 error:
1572 return ret;
1573 }
1574
1575 /*
1576 * This is an extension of create session that is ONLY and SHOULD only be used
1577 * by the lttng command line program. It exists to avoid using URI parsing in
1578 * the lttng client.
1579 *
1580 * We need the date and time for the trace path subdirectory for the case where
1581 * the user does NOT define one using either -o or -U. Using the normal
1582 * lttng_create_session API call, we have no clue on the session daemon side if
1583 * the URL was generated automatically by the client or define by the user.
1584 *
1585 * So this function "wrapper" is hidden from the public API, takes the datetime
1586 * string and appends it if necessary to the URI subdirectory before sending it
1587 * to the session daemon.
1588 *
1589 * With this extra function, the lttng_create_session call behavior is not
1590 * changed and the timestamp is appended to the URI on the session daemon side
1591 * if necessary.
1592 */
1593 int _lttng_create_session_ext(const char *name, const char *url,
1594 const char *datetime)
1595 {
1596 int ret;
1597 ssize_t size;
1598 struct lttcomm_session_msg lsm;
1599 struct lttng_uri *uris = NULL;
1600
1601 if (name == NULL || datetime == NULL) {
1602 return -LTTNG_ERR_INVALID;
1603 }
1604
1605 memset(&lsm, 0, sizeof(lsm));
1606
1607 lsm.cmd_type = LTTNG_CREATE_SESSION;
1608 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1609
1610 /* There should never be a data URL */
1611 size = parse_str_urls_to_uri(url, NULL, &uris);
1612 if (size < 0) {
1613 return -LTTNG_ERR_INVALID;
1614 }
1615
1616 lsm.u.uri.size = size;
1617
1618 if (size > 0 && uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
1619 ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s-%s", name,
1620 datetime);
1621 if (ret < 0) {
1622 PERROR("snprintf uri subdir");
1623 return -LTTNG_ERR_FATAL;
1624 }
1625 }
1626
1627 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1628 NULL);
1629 }
1630
1631 /*
1632 * For a given session name, this call checks if the data is ready to be read
1633 * or is still being extracted by the consumer(s) hence not ready to be used by
1634 * any readers.
1635 */
1636 int lttng_data_pending(const char *session_name)
1637 {
1638 int ret;
1639 struct lttcomm_session_msg lsm;
1640
1641 if (session_name == NULL) {
1642 return -LTTNG_ERR_INVALID;
1643 }
1644
1645 lsm.cmd_type = LTTNG_DATA_PENDING;
1646
1647 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1648
1649 ret = ask_sessiond(&lsm, NULL);
1650
1651 /*
1652 * The ask_sessiond function negate the return code if it's not LTTNG_OK so
1653 * getting -1 means that the reply ret_code was 1 thus meaning that the
1654 * data is available. Yes it is hackish but for now this is the only way.
1655 */
1656 if (ret == -1) {
1657 ret = 1;
1658 }
1659
1660 return ret;
1661 }
1662
1663 /*
1664 * lib constructor
1665 */
1666 static void __attribute__((constructor)) init()
1667 {
1668 /* Set default session group */
1669 lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
1670 /* Set socket for health check */
1671 (void) set_health_socket_path();
1672 }
1673
1674 /*
1675 * lib destructor
1676 */
1677 static void __attribute__((destructor)) lttng_ctl_exit()
1678 {
1679 free(tracing_group);
1680 }
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