Use the new functions for default subbuf sizes
[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 event and/or channel.
753 * If event_name is NULL, the context is applied to all events of the channel.
754 * If channel_name is NULL, a lookup of the event's channel is done.
755 * If both are NULL, the context is applied to all events of all channels.
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 /* Copy event name */
778 copy_string(lsm.u.context.event_name, event_name,
779 sizeof(lsm.u.context.event_name));
780
781 copy_lttng_domain(&lsm.domain, &handle->domain);
782
783 memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
784
785 copy_string(lsm.session.name, handle->session_name,
786 sizeof(lsm.session.name));
787
788 return ask_sessiond(&lsm, NULL);
789 }
790
791 /*
792 * Enable event(s) for a channel.
793 * If no event name is specified, all events are enabled.
794 * If no channel name is specified, the default 'channel0' is used.
795 * Returns size of returned session payload data or a negative error code.
796 */
797 int lttng_enable_event(struct lttng_handle *handle,
798 struct lttng_event *ev, const char *channel_name)
799 {
800 struct lttcomm_session_msg lsm;
801
802 if (handle == NULL || ev == NULL) {
803 return -LTTNG_ERR_INVALID;
804 }
805
806 memset(&lsm, 0, sizeof(lsm));
807
808 /* If no channel name, we put the default name */
809 if (channel_name == NULL) {
810 copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
811 sizeof(lsm.u.enable.channel_name));
812 } else {
813 copy_string(lsm.u.enable.channel_name, channel_name,
814 sizeof(lsm.u.enable.channel_name));
815 }
816
817 copy_lttng_domain(&lsm.domain, &handle->domain);
818
819 if (ev->name[0] != '\0') {
820 lsm.cmd_type = LTTNG_ENABLE_EVENT;
821 } else {
822 lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
823 }
824 memcpy(&lsm.u.enable.event, ev, sizeof(lsm.u.enable.event));
825
826 copy_string(lsm.session.name, handle->session_name,
827 sizeof(lsm.session.name));
828
829 return ask_sessiond(&lsm, NULL);
830 }
831
832 /*
833 * set filter for an event
834 * Return negative error value on error.
835 * Return size of returned session payload data if OK.
836 */
837
838 int lttng_set_event_filter(struct lttng_handle *handle,
839 const char *event_name, const char *channel_name,
840 const char *filter_expression)
841 {
842 struct lttcomm_session_msg lsm;
843 struct filter_parser_ctx *ctx;
844 FILE *fmem;
845 int ret = 0;
846
847 /* Safety check. */
848 if (handle == NULL) {
849 return -LTTNG_ERR_INVALID;
850 }
851
852 if (!filter_expression) {
853 return 0;
854 }
855
856 /*
857 * casting const to non-const, as the underlying function will
858 * use it in read-only mode.
859 */
860 fmem = lttng_fmemopen((void *) filter_expression,
861 strlen(filter_expression), "r");
862 if (!fmem) {
863 fprintf(stderr, "Error opening memory as stream\n");
864 return -LTTNG_ERR_FILTER_NOMEM;
865 }
866 ctx = filter_parser_ctx_alloc(fmem);
867 if (!ctx) {
868 fprintf(stderr, "Error allocating parser\n");
869 ret = -LTTNG_ERR_FILTER_NOMEM;
870 goto alloc_error;
871 }
872 ret = filter_parser_ctx_append_ast(ctx);
873 if (ret) {
874 fprintf(stderr, "Parse error\n");
875 ret = -LTTNG_ERR_FILTER_INVAL;
876 goto parse_error;
877 }
878 ret = filter_visitor_set_parent(ctx);
879 if (ret) {
880 fprintf(stderr, "Set parent error\n");
881 ret = -LTTNG_ERR_FILTER_INVAL;
882 goto parse_error;
883 }
884 if (print_xml) {
885 ret = filter_visitor_print_xml(ctx, stdout, 0);
886 if (ret) {
887 fflush(stdout);
888 fprintf(stderr, "XML print error\n");
889 ret = -LTTNG_ERR_FILTER_INVAL;
890 goto parse_error;
891 }
892 }
893
894 dbg_printf("Generating IR... ");
895 fflush(stdout);
896 ret = filter_visitor_ir_generate(ctx);
897 if (ret) {
898 fprintf(stderr, "Generate IR error\n");
899 ret = -LTTNG_ERR_FILTER_INVAL;
900 goto parse_error;
901 }
902 dbg_printf("done\n");
903
904 dbg_printf("Validating IR... ");
905 fflush(stdout);
906 ret = filter_visitor_ir_check_binary_op_nesting(ctx);
907 if (ret) {
908 ret = -LTTNG_ERR_FILTER_INVAL;
909 goto parse_error;
910 }
911 dbg_printf("done\n");
912
913 dbg_printf("Generating bytecode... ");
914 fflush(stdout);
915 ret = filter_visitor_bytecode_generate(ctx);
916 if (ret) {
917 fprintf(stderr, "Generate bytecode error\n");
918 ret = -LTTNG_ERR_FILTER_INVAL;
919 goto parse_error;
920 }
921 dbg_printf("done\n");
922 dbg_printf("Size of bytecode generated: %u bytes.\n",
923 bytecode_get_len(&ctx->bytecode->b));
924
925 memset(&lsm, 0, sizeof(lsm));
926
927 lsm.cmd_type = LTTNG_SET_FILTER;
928
929 /* Copy channel name */
930 copy_string(lsm.u.filter.channel_name, channel_name,
931 sizeof(lsm.u.filter.channel_name));
932 /* Copy event name */
933 copy_string(lsm.u.filter.event_name, event_name,
934 sizeof(lsm.u.filter.event_name));
935 lsm.u.filter.bytecode_len = sizeof(ctx->bytecode->b)
936 + bytecode_get_len(&ctx->bytecode->b);
937
938 copy_lttng_domain(&lsm.domain, &handle->domain);
939
940 copy_string(lsm.session.name, handle->session_name,
941 sizeof(lsm.session.name));
942
943 ret = ask_sessiond_varlen(&lsm, &ctx->bytecode->b,
944 lsm.u.filter.bytecode_len, NULL);
945
946 filter_bytecode_free(ctx);
947 filter_ir_free(ctx);
948 filter_parser_ctx_free(ctx);
949 if (fclose(fmem) != 0) {
950 perror("fclose");
951 }
952 return ret;
953
954 parse_error:
955 filter_bytecode_free(ctx);
956 filter_ir_free(ctx);
957 filter_parser_ctx_free(ctx);
958 alloc_error:
959 if (fclose(fmem) != 0) {
960 perror("fclose");
961 }
962 return ret;
963 }
964
965 /*
966 * Disable event(s) of a channel and domain.
967 * If no event name is specified, all events are disabled.
968 * If no channel name is specified, the default 'channel0' is used.
969 * Returns size of returned session payload data or a negative error code.
970 */
971 int lttng_disable_event(struct lttng_handle *handle, const char *name,
972 const char *channel_name)
973 {
974 struct lttcomm_session_msg lsm;
975
976 if (handle == NULL) {
977 return -LTTNG_ERR_INVALID;
978 }
979
980 memset(&lsm, 0, sizeof(lsm));
981
982 if (channel_name) {
983 copy_string(lsm.u.disable.channel_name, channel_name,
984 sizeof(lsm.u.disable.channel_name));
985 } else {
986 copy_string(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME,
987 sizeof(lsm.u.disable.channel_name));
988 }
989
990 copy_lttng_domain(&lsm.domain, &handle->domain);
991
992 if (name != NULL) {
993 copy_string(lsm.u.disable.name, name, sizeof(lsm.u.disable.name));
994 lsm.cmd_type = LTTNG_DISABLE_EVENT;
995 } else {
996 lsm.cmd_type = LTTNG_DISABLE_ALL_EVENT;
997 }
998
999 copy_string(lsm.session.name, handle->session_name,
1000 sizeof(lsm.session.name));
1001
1002 return ask_sessiond(&lsm, NULL);
1003 }
1004
1005 /*
1006 * Enable channel per domain
1007 * Returns size of returned session payload data or a negative error code.
1008 */
1009 int lttng_enable_channel(struct lttng_handle *handle,
1010 struct lttng_channel *chan)
1011 {
1012 struct lttcomm_session_msg lsm;
1013
1014 /*
1015 * NULL arguments are forbidden. No default values.
1016 */
1017 if (handle == NULL || chan == NULL) {
1018 return -LTTNG_ERR_INVALID;
1019 }
1020
1021 memset(&lsm, 0, sizeof(lsm));
1022
1023 memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
1024
1025 lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
1026
1027 copy_lttng_domain(&lsm.domain, &handle->domain);
1028
1029 copy_string(lsm.session.name, handle->session_name,
1030 sizeof(lsm.session.name));
1031
1032 return ask_sessiond(&lsm, NULL);
1033 }
1034
1035 /*
1036 * All tracing will be stopped for registered events of the channel.
1037 * Returns size of returned session payload data or a negative error code.
1038 */
1039 int lttng_disable_channel(struct lttng_handle *handle, const char *name)
1040 {
1041 struct lttcomm_session_msg lsm;
1042
1043 /* Safety check. Both are mandatory */
1044 if (handle == NULL || name == NULL) {
1045 return -LTTNG_ERR_INVALID;
1046 }
1047
1048 memset(&lsm, 0, sizeof(lsm));
1049
1050 lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
1051
1052 copy_string(lsm.u.disable.channel_name, name,
1053 sizeof(lsm.u.disable.channel_name));
1054
1055 copy_lttng_domain(&lsm.domain, &handle->domain);
1056
1057 copy_string(lsm.session.name, handle->session_name,
1058 sizeof(lsm.session.name));
1059
1060 return ask_sessiond(&lsm, NULL);
1061 }
1062
1063 /*
1064 * Lists all available tracepoints of domain.
1065 * Sets the contents of the events array.
1066 * Returns the number of lttng_event entries in events;
1067 * on error, returns a negative value.
1068 */
1069 int lttng_list_tracepoints(struct lttng_handle *handle,
1070 struct lttng_event **events)
1071 {
1072 int ret;
1073 struct lttcomm_session_msg lsm;
1074
1075 if (handle == NULL) {
1076 return -LTTNG_ERR_INVALID;
1077 }
1078
1079 lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
1080 copy_lttng_domain(&lsm.domain, &handle->domain);
1081
1082 ret = ask_sessiond(&lsm, (void **) events);
1083 if (ret < 0) {
1084 return ret;
1085 }
1086
1087 return ret / sizeof(struct lttng_event);
1088 }
1089
1090 /*
1091 * Lists all available tracepoint fields of domain.
1092 * Sets the contents of the event field array.
1093 * Returns the number of lttng_event_field entries in events;
1094 * on error, returns a negative value.
1095 */
1096 int lttng_list_tracepoint_fields(struct lttng_handle *handle,
1097 struct lttng_event_field **fields)
1098 {
1099 int ret;
1100 struct lttcomm_session_msg lsm;
1101
1102 if (handle == NULL) {
1103 return -LTTNG_ERR_INVALID;
1104 }
1105
1106 lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
1107 copy_lttng_domain(&lsm.domain, &handle->domain);
1108
1109 ret = ask_sessiond(&lsm, (void **) fields);
1110 if (ret < 0) {
1111 return ret;
1112 }
1113
1114 return ret / sizeof(struct lttng_event_field);
1115 }
1116
1117 /*
1118 * Returns a human readable string describing
1119 * the error code (a negative value).
1120 */
1121 const char *lttng_strerror(int code)
1122 {
1123 return error_get_str(code);
1124 }
1125
1126 /*
1127 * Create a brand new session using name and url for destination.
1128 *
1129 * Returns LTTNG_OK on success or a negative error code.
1130 */
1131 int lttng_create_session(const char *name, const char *url)
1132 {
1133 ssize_t size;
1134 struct lttcomm_session_msg lsm;
1135 struct lttng_uri *uris = NULL;
1136
1137 if (name == NULL) {
1138 return -LTTNG_ERR_INVALID;
1139 }
1140
1141 memset(&lsm, 0, sizeof(lsm));
1142
1143 lsm.cmd_type = LTTNG_CREATE_SESSION;
1144 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1145
1146 /* There should never be a data URL */
1147 size = parse_str_urls_to_uri(url, NULL, &uris);
1148 if (size < 0) {
1149 return -LTTNG_ERR_INVALID;
1150 }
1151
1152 lsm.u.uri.size = size;
1153
1154 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1155 NULL);
1156 }
1157
1158 /*
1159 * Destroy session using name.
1160 * Returns size of returned session payload data or a negative error code.
1161 */
1162 int lttng_destroy_session(const char *session_name)
1163 {
1164 struct lttcomm_session_msg lsm;
1165
1166 if (session_name == NULL) {
1167 return -LTTNG_ERR_INVALID;
1168 }
1169
1170 lsm.cmd_type = LTTNG_DESTROY_SESSION;
1171
1172 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1173
1174 return ask_sessiond(&lsm, NULL);
1175 }
1176
1177 /*
1178 * Ask the session daemon for all available sessions.
1179 * Sets the contents of the sessions array.
1180 * Returns the number of lttng_session entries in sessions;
1181 * on error, returns a negative value.
1182 */
1183 int lttng_list_sessions(struct lttng_session **sessions)
1184 {
1185 int ret;
1186 struct lttcomm_session_msg lsm;
1187
1188 lsm.cmd_type = LTTNG_LIST_SESSIONS;
1189 ret = ask_sessiond(&lsm, (void**) sessions);
1190 if (ret < 0) {
1191 return ret;
1192 }
1193
1194 return ret / sizeof(struct lttng_session);
1195 }
1196
1197 /*
1198 * Ask the session daemon for all available domains of a session.
1199 * Sets the contents of the domains array.
1200 * Returns the number of lttng_domain entries in domains;
1201 * on error, returns a negative value.
1202 */
1203 int lttng_list_domains(const char *session_name,
1204 struct lttng_domain **domains)
1205 {
1206 int ret;
1207 struct lttcomm_session_msg lsm;
1208
1209 if (session_name == NULL) {
1210 return -LTTNG_ERR_INVALID;
1211 }
1212
1213 lsm.cmd_type = LTTNG_LIST_DOMAINS;
1214
1215 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1216
1217 ret = ask_sessiond(&lsm, (void**) domains);
1218 if (ret < 0) {
1219 return ret;
1220 }
1221
1222 return ret / sizeof(struct lttng_domain);
1223 }
1224
1225 /*
1226 * Ask the session daemon for all available channels of a session.
1227 * Sets the contents of the channels array.
1228 * Returns the number of lttng_channel entries in channels;
1229 * on error, returns a negative value.
1230 */
1231 int lttng_list_channels(struct lttng_handle *handle,
1232 struct lttng_channel **channels)
1233 {
1234 int ret;
1235 struct lttcomm_session_msg lsm;
1236
1237 if (handle == NULL) {
1238 return -LTTNG_ERR_INVALID;
1239 }
1240
1241 lsm.cmd_type = LTTNG_LIST_CHANNELS;
1242 copy_string(lsm.session.name, handle->session_name,
1243 sizeof(lsm.session.name));
1244
1245 copy_lttng_domain(&lsm.domain, &handle->domain);
1246
1247 ret = ask_sessiond(&lsm, (void**) channels);
1248 if (ret < 0) {
1249 return ret;
1250 }
1251
1252 return ret / sizeof(struct lttng_channel);
1253 }
1254
1255 /*
1256 * Ask the session daemon for all available events of a session channel.
1257 * Sets the contents of the events array.
1258 * Returns the number of lttng_event entries in events;
1259 * on error, returns a negative value.
1260 */
1261 int lttng_list_events(struct lttng_handle *handle,
1262 const char *channel_name, struct lttng_event **events)
1263 {
1264 int ret;
1265 struct lttcomm_session_msg lsm;
1266
1267 /* Safety check. An handle and channel name are mandatory */
1268 if (handle == NULL || channel_name == NULL) {
1269 return -LTTNG_ERR_INVALID;
1270 }
1271
1272 lsm.cmd_type = LTTNG_LIST_EVENTS;
1273 copy_string(lsm.session.name, handle->session_name,
1274 sizeof(lsm.session.name));
1275 copy_string(lsm.u.list.channel_name, channel_name,
1276 sizeof(lsm.u.list.channel_name));
1277
1278 copy_lttng_domain(&lsm.domain, &handle->domain);
1279
1280 ret = ask_sessiond(&lsm, (void**) events);
1281 if (ret < 0) {
1282 return ret;
1283 }
1284
1285 return ret / sizeof(struct lttng_event);
1286 }
1287
1288 /*
1289 * Sets the tracing_group variable with name.
1290 * This function allocates memory pointed to by tracing_group.
1291 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1292 */
1293 int lttng_set_tracing_group(const char *name)
1294 {
1295 if (name == NULL) {
1296 return -LTTNG_ERR_INVALID;
1297 }
1298
1299 if (asprintf(&tracing_group, "%s", name) < 0) {
1300 return -LTTNG_ERR_FATAL;
1301 }
1302
1303 return 0;
1304 }
1305
1306 /*
1307 * Returns size of returned session payload data or a negative error code.
1308 */
1309 int lttng_calibrate(struct lttng_handle *handle,
1310 struct lttng_calibrate *calibrate)
1311 {
1312 struct lttcomm_session_msg lsm;
1313
1314 /* Safety check. NULL pointer are forbidden */
1315 if (handle == NULL || calibrate == NULL) {
1316 return -LTTNG_ERR_INVALID;
1317 }
1318
1319 lsm.cmd_type = LTTNG_CALIBRATE;
1320 copy_lttng_domain(&lsm.domain, &handle->domain);
1321
1322 memcpy(&lsm.u.calibrate, calibrate, sizeof(lsm.u.calibrate));
1323
1324 return ask_sessiond(&lsm, NULL);
1325 }
1326
1327 /*
1328 * Set default channel attributes.
1329 * If either or both of the arguments are null, attr content is zeroe'd.
1330 */
1331 void lttng_channel_set_default_attr(struct lttng_domain *domain,
1332 struct lttng_channel_attr *attr)
1333 {
1334 /* Safety check */
1335 if (attr == NULL || domain == NULL) {
1336 return;
1337 }
1338
1339 memset(attr, 0, sizeof(struct lttng_channel_attr));
1340
1341 switch (domain->type) {
1342 case LTTNG_DOMAIN_KERNEL:
1343 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1344 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1345 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1346
1347 attr->subbuf_size = default_get_kernel_channel_subbuf_size();
1348 attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
1349 attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
1350 break;
1351 case LTTNG_DOMAIN_UST:
1352 #if 0
1353 case LTTNG_DOMAIN_UST_EXEC_NAME:
1354 case LTTNG_DOMAIN_UST_PID:
1355 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1356 #endif
1357 attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
1358 attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
1359 attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
1360
1361 attr->subbuf_size = default_get_ust_channel_subbuf_size();
1362 attr->num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
1363 attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
1364 break;
1365 default:
1366 /* Default behavior: leave set to 0. */
1367 break;
1368 }
1369 }
1370
1371 /*
1372 * Check if session daemon is alive.
1373 *
1374 * Return 1 if alive or 0 if not.
1375 * On error returns a negative value.
1376 */
1377 int lttng_session_daemon_alive(void)
1378 {
1379 int ret;
1380
1381 ret = set_session_daemon_path();
1382 if (ret < 0) {
1383 /* Error */
1384 return ret;
1385 }
1386
1387 if (strlen(sessiond_sock_path) == 0) {
1388 /*
1389 * No socket path set. Weird error which means the constructor was not
1390 * called.
1391 */
1392 assert(0);
1393 }
1394
1395 ret = try_connect_sessiond(sessiond_sock_path);
1396 if (ret < 0) {
1397 /* Not alive */
1398 return 0;
1399 }
1400
1401 /* Is alive */
1402 return 1;
1403 }
1404
1405 /*
1406 * Set URL for a consumer for a session and domain.
1407 *
1408 * Return 0 on success, else a negative value.
1409 */
1410 int lttng_set_consumer_url(struct lttng_handle *handle,
1411 const char *control_url, const char *data_url)
1412 {
1413 ssize_t size;
1414 struct lttcomm_session_msg lsm;
1415 struct lttng_uri *uris = NULL;
1416
1417 if (handle == NULL || (control_url == NULL && data_url == NULL)) {
1418 return -LTTNG_ERR_INVALID;
1419 }
1420
1421 memset(&lsm, 0, sizeof(lsm));
1422
1423 lsm.cmd_type = LTTNG_SET_CONSUMER_URI;
1424
1425 copy_string(lsm.session.name, handle->session_name,
1426 sizeof(lsm.session.name));
1427 copy_lttng_domain(&lsm.domain, &handle->domain);
1428
1429 size = parse_str_urls_to_uri(control_url, data_url, &uris);
1430 if (size < 0) {
1431 return -LTTNG_ERR_INVALID;
1432 }
1433
1434 lsm.u.uri.size = size;
1435
1436 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1437 NULL);
1438 }
1439
1440 /*
1441 * Enable consumer for a session and domain.
1442 *
1443 * Return 0 on success, else a negative value.
1444 */
1445 int lttng_enable_consumer(struct lttng_handle *handle)
1446 {
1447 struct lttcomm_session_msg lsm;
1448
1449 if (handle == NULL) {
1450 return -LTTNG_ERR_INVALID;
1451 }
1452
1453 lsm.cmd_type = LTTNG_ENABLE_CONSUMER;
1454
1455 copy_string(lsm.session.name, handle->session_name,
1456 sizeof(lsm.session.name));
1457 copy_lttng_domain(&lsm.domain, &handle->domain);
1458
1459 return ask_sessiond(&lsm, NULL);
1460 }
1461
1462 /*
1463 * Disable consumer for a session and domain.
1464 *
1465 * Return 0 on success, else a negative value.
1466 */
1467 int lttng_disable_consumer(struct lttng_handle *handle)
1468 {
1469 struct lttcomm_session_msg lsm;
1470
1471 if (handle == NULL) {
1472 return -LTTNG_ERR_INVALID;
1473 }
1474
1475 lsm.cmd_type = LTTNG_DISABLE_CONSUMER;
1476
1477 copy_string(lsm.session.name, handle->session_name,
1478 sizeof(lsm.session.name));
1479 copy_lttng_domain(&lsm.domain, &handle->domain);
1480
1481 return ask_sessiond(&lsm, NULL);
1482 }
1483
1484 /*
1485 * Set health socket path by putting it in the global health_sock_path
1486 * variable.
1487 *
1488 * Returns 0 on success or assert(0) on ENOMEM.
1489 */
1490 static int set_health_socket_path(void)
1491 {
1492 int ret;
1493 int in_tgroup = 0; /* In tracing group */
1494 uid_t uid;
1495 const char *home;
1496
1497 uid = getuid();
1498
1499 if (uid != 0) {
1500 /* Are we in the tracing group ? */
1501 in_tgroup = check_tracing_group(tracing_group);
1502 }
1503
1504 if ((uid == 0) || in_tgroup) {
1505 copy_string(health_sock_path, DEFAULT_GLOBAL_HEALTH_UNIX_SOCK,
1506 sizeof(health_sock_path));
1507 }
1508
1509 if (uid != 0) {
1510 /*
1511 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
1512 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
1513 */
1514 home = getenv("HOME");
1515 if (home == NULL) {
1516 /* Fallback in /tmp .. */
1517 home = "/tmp";
1518 }
1519
1520 ret = snprintf(health_sock_path, sizeof(health_sock_path),
1521 DEFAULT_HOME_HEALTH_UNIX_SOCK, home);
1522 if ((ret < 0) || (ret >= sizeof(health_sock_path))) {
1523 /* ENOMEM at this point... just kill the control lib. */
1524 assert(0);
1525 }
1526 }
1527
1528 return 0;
1529 }
1530
1531 /*
1532 * Check session daemon health for a specific health component.
1533 *
1534 * Return 0 if health is OK or else 1 if BAD.
1535 *
1536 * Any other negative value is a lttng error code which can be translated with
1537 * lttng_strerror().
1538 */
1539 int lttng_health_check(enum lttng_health_component c)
1540 {
1541 int sock, ret;
1542 struct lttcomm_health_msg msg;
1543 struct lttcomm_health_data reply;
1544
1545 /* Connect to the sesssion daemon */
1546 sock = lttcomm_connect_unix_sock(health_sock_path);
1547 if (sock < 0) {
1548 ret = -LTTNG_ERR_NO_SESSIOND;
1549 goto error;
1550 }
1551
1552 msg.cmd = LTTNG_HEALTH_CHECK;
1553 msg.component = c;
1554
1555 ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
1556 if (ret < 0) {
1557 ret = -LTTNG_ERR_FATAL;
1558 goto close_error;
1559 }
1560
1561 ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
1562 if (ret < 0) {
1563 ret = -LTTNG_ERR_FATAL;
1564 goto close_error;
1565 }
1566
1567 ret = reply.ret_code;
1568
1569 close_error:
1570 close(sock);
1571
1572 error:
1573 return ret;
1574 }
1575
1576 /*
1577 * This is an extension of create session that is ONLY and SHOULD only be used
1578 * by the lttng command line program. It exists to avoid using URI parsing in
1579 * the lttng client.
1580 *
1581 * We need the date and time for the trace path subdirectory for the case where
1582 * the user does NOT define one using either -o or -U. Using the normal
1583 * lttng_create_session API call, we have no clue on the session daemon side if
1584 * the URL was generated automatically by the client or define by the user.
1585 *
1586 * So this function "wrapper" is hidden from the public API, takes the datetime
1587 * string and appends it if necessary to the URI subdirectory before sending it
1588 * to the session daemon.
1589 *
1590 * With this extra function, the lttng_create_session call behavior is not
1591 * changed and the timestamp is appended to the URI on the session daemon side
1592 * if necessary.
1593 */
1594 int _lttng_create_session_ext(const char *name, const char *url,
1595 const char *datetime)
1596 {
1597 int ret;
1598 ssize_t size;
1599 struct lttcomm_session_msg lsm;
1600 struct lttng_uri *uris = NULL;
1601
1602 if (name == NULL || datetime == NULL) {
1603 return -LTTNG_ERR_INVALID;
1604 }
1605
1606 memset(&lsm, 0, sizeof(lsm));
1607
1608 lsm.cmd_type = LTTNG_CREATE_SESSION;
1609 copy_string(lsm.session.name, name, sizeof(lsm.session.name));
1610
1611 /* There should never be a data URL */
1612 size = parse_str_urls_to_uri(url, NULL, &uris);
1613 if (size < 0) {
1614 return -LTTNG_ERR_INVALID;
1615 }
1616
1617 lsm.u.uri.size = size;
1618
1619 if (size > 0 && uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
1620 ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s-%s", name,
1621 datetime);
1622 if (ret < 0) {
1623 PERROR("snprintf uri subdir");
1624 return -LTTNG_ERR_FATAL;
1625 }
1626 }
1627
1628 return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
1629 NULL);
1630 }
1631
1632 /*
1633 * For a given session name, this call checks if the data is ready to be read
1634 * or is still being extracted by the consumer(s) hence not ready to be used by
1635 * any readers.
1636 */
1637 int lttng_data_pending(const char *session_name)
1638 {
1639 int ret;
1640 struct lttcomm_session_msg lsm;
1641
1642 if (session_name == NULL) {
1643 return -LTTNG_ERR_INVALID;
1644 }
1645
1646 lsm.cmd_type = LTTNG_DATA_PENDING;
1647
1648 copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
1649
1650 ret = ask_sessiond(&lsm, NULL);
1651
1652 /*
1653 * The ask_sessiond function negate the return code if it's not LTTNG_OK so
1654 * getting -1 means that the reply ret_code was 1 thus meaning that the
1655 * data is available. Yes it is hackish but for now this is the only way.
1656 */
1657 if (ret == -1) {
1658 ret = 1;
1659 }
1660
1661 return ret;
1662 }
1663
1664 /*
1665 * lib constructor
1666 */
1667 static void __attribute__((constructor)) init()
1668 {
1669 /* Set default session group */
1670 lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
1671 /* Set socket for health check */
1672 (void) set_health_socket_path();
1673 }
1674
1675 /*
1676 * lib destructor
1677 */
1678 static void __attribute__((destructor)) lttng_ctl_exit()
1679 {
1680 free(tracing_group);
1681 }
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