4 * Linux Trace Toolkit Control Library
6 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
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.
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.
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
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 <common/utils.h>
36 #include <lttng/lttng.h>
38 #include "filter/filter-ast.h"
39 #include "filter/filter-parser.h"
40 #include "filter/filter-bytecode.h"
41 #include "filter/memstream.h"
42 #include "lttng-ctl-helper.h"
45 static const int print_xml
= 1;
46 #define dbg_printf(fmt, args...) \
47 printf("[debug liblttng-ctl] " fmt, ## args)
49 static const int print_xml
= 0;
50 #define dbg_printf(fmt, args...) \
52 /* do nothing but check printf format */ \
54 printf("[debug liblttnctl] " fmt, ## args); \
59 /* Socket to session daemon for communication */
60 static int sessiond_socket
;
61 static char sessiond_sock_path
[PATH_MAX
];
62 static char health_sock_path
[PATH_MAX
];
65 static char *tracing_group
;
71 * Those two variables are used by error.h to silent or control the verbosity of
72 * error message. They are global to the library so application linking with it
73 * are able to compile correctly and also control verbosity of the library.
76 int lttng_opt_verbose
;
79 * Copy string from src to dst and enforce null terminated byte.
82 void lttng_ctl_copy_string(char *dst
, const char *src
, size_t len
)
85 strncpy(dst
, src
, len
);
86 /* Enforce the NULL terminated byte */
94 * Copy domain to lttcomm_session_msg domain.
96 * If domain is unknown, default domain will be the kernel.
99 void lttng_ctl_copy_lttng_domain(struct lttng_domain
*dst
,
100 struct lttng_domain
*src
)
104 case LTTNG_DOMAIN_KERNEL
:
105 case LTTNG_DOMAIN_UST
:
106 memcpy(dst
, src
, sizeof(struct lttng_domain
));
109 memset(dst
, 0, sizeof(struct lttng_domain
));
116 * Send lttcomm_session_msg to the session daemon.
118 * On success, returns the number of bytes sent (>=0)
119 * On error, returns -1
121 static int send_session_msg(struct lttcomm_session_msg
*lsm
)
126 ret
= -LTTNG_ERR_NO_SESSIOND
;
130 DBG("LSM cmd type : %d", lsm
->cmd_type
);
132 ret
= lttcomm_send_creds_unix_sock(sessiond_socket
, lsm
,
133 sizeof(struct lttcomm_session_msg
));
135 ret
= -LTTNG_ERR_FATAL
;
143 * Send var len data to the session daemon.
145 * On success, returns the number of bytes sent (>=0)
146 * On error, returns -1
148 static int send_session_varlen(void *data
, size_t len
)
153 ret
= -LTTNG_ERR_NO_SESSIOND
;
162 ret
= lttcomm_send_unix_sock(sessiond_socket
, data
, len
);
164 ret
= -LTTNG_ERR_FATAL
;
172 * Receive data from the sessiond socket.
174 * On success, returns the number of bytes received (>=0)
175 * On error, returns -1 (recvmsg() error) or -ENOTCONN
177 static int recv_data_sessiond(void *buf
, size_t len
)
182 ret
= -LTTNG_ERR_NO_SESSIOND
;
186 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
188 ret
= -LTTNG_ERR_FATAL
;
196 * Check if we are in the specified group.
198 * If yes return 1, else return -1.
200 static int check_tracing_group(const char *grp_name
)
202 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
204 int grp_list_size
, grp_id
, i
;
207 /* Get GID of group 'tracing' */
208 grp_tracing
= getgrnam(grp_name
);
210 /* If grp_tracing is NULL, the group does not exist. */
214 /* Get number of supplementary group IDs */
215 grp_list_size
= getgroups(0, NULL
);
216 if (grp_list_size
< 0) {
221 /* Alloc group list of the right size */
222 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
227 grp_id
= getgroups(grp_list_size
, grp_list
);
233 for (i
= 0; i
< grp_list_size
; i
++) {
234 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
248 * Try connect to session daemon with sock_path.
250 * Return 0 on success, else -1
252 static int try_connect_sessiond(const char *sock_path
)
256 /* If socket exist, we check if the daemon listens for connect. */
257 ret
= access(sock_path
, F_OK
);
263 ret
= lttcomm_connect_unix_sock(sock_path
);
269 ret
= lttcomm_close_unix_sock(ret
);
271 perror("lttcomm_close_unix_sock");
281 * Set sessiond socket path by putting it in the global sessiond_sock_path
284 * Returns 0 on success, negative value on failure (the sessiond socket path
285 * is somehow too long or ENOMEM).
287 static int set_session_daemon_path(void)
289 int in_tgroup
= 0; /* In tracing group */
295 /* Are we in the tracing group ? */
296 in_tgroup
= check_tracing_group(tracing_group
);
299 if ((uid
== 0) || in_tgroup
) {
300 lttng_ctl_copy_string(sessiond_sock_path
,
301 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
, sizeof(sessiond_sock_path
));
309 ret
= try_connect_sessiond(sessiond_sock_path
);
313 /* Global session daemon not available... */
315 /* ...or not in tracing group (and not root), default */
318 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
319 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
321 ret
= snprintf(sessiond_sock_path
, sizeof(sessiond_sock_path
),
322 DEFAULT_HOME_CLIENT_UNIX_SOCK
, utils_get_home_dir());
323 if ((ret
< 0) || (ret
>= sizeof(sessiond_sock_path
))) {
335 * Connect to the LTTng session daemon.
337 * On success, return 0. On error, return -1.
339 static int connect_sessiond(void)
343 /* Don't try to connect if already connected. */
348 ret
= set_session_daemon_path();
353 /* Connect to the sesssion daemon */
354 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
359 sessiond_socket
= ret
;
369 * Clean disconnect from the session daemon.
370 * On success, return 0. On error, return -1.
372 static int disconnect_sessiond(void)
377 ret
= lttcomm_close_unix_sock(sessiond_socket
);
386 * Ask the session daemon a specific command and put the data into buf.
387 * Takes extra var. len. data as input to send to the session daemon.
389 * Return size of data (only payload, not header) or a negative error code.
392 int lttng_ctl_ask_sessiond_varlen(struct lttcomm_session_msg
*lsm
,
393 void *vardata
, size_t varlen
, void **buf
)
398 struct lttcomm_lttng_msg llm
;
400 ret
= connect_sessiond();
402 ret
= -LTTNG_ERR_NO_SESSIOND
;
406 /* Send command to session daemon */
407 ret
= send_session_msg(lsm
);
409 /* Ret value is a valid lttng error code. */
412 /* Send var len data */
413 ret
= send_session_varlen(vardata
, varlen
);
415 /* Ret value is a valid lttng error code. */
419 /* Get header from data transmission */
420 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
422 /* Ret value is a valid lttng error code. */
426 /* Check error code if OK */
427 if (llm
.ret_code
!= LTTNG_OK
) {
432 size
= llm
.data_size
;
434 /* If client free with size 0 */
442 data
= (void*) malloc(size
);
444 /* Get payload data */
445 ret
= recv_data_sessiond(data
, size
);
452 * Extra protection not to dereference a NULL pointer. If buf is NULL at
453 * this point, an error is returned and data is freed.
456 ret
= -LTTNG_ERR_INVALID
;
465 disconnect_sessiond();
470 * Create lttng handle and return pointer.
471 * The returned pointer will be NULL in case of malloc() error.
473 struct lttng_handle
*lttng_create_handle(const char *session_name
,
474 struct lttng_domain
*domain
)
476 struct lttng_handle
*handle
= NULL
;
478 if (domain
== NULL
) {
482 handle
= malloc(sizeof(struct lttng_handle
));
483 if (handle
== NULL
) {
484 PERROR("malloc handle");
488 /* Copy session name */
489 lttng_ctl_copy_string(handle
->session_name
, session_name
,
490 sizeof(handle
->session_name
));
492 /* Copy lttng domain */
493 lttng_ctl_copy_lttng_domain(&handle
->domain
, domain
);
500 * Destroy handle by free(3) the pointer.
502 void lttng_destroy_handle(struct lttng_handle
*handle
)
508 * Register an outside consumer.
509 * Returns size of returned session payload data or a negative error code.
511 int lttng_register_consumer(struct lttng_handle
*handle
,
512 const char *socket_path
)
514 struct lttcomm_session_msg lsm
;
516 if (handle
== NULL
|| socket_path
== NULL
) {
517 return -LTTNG_ERR_INVALID
;
520 lsm
.cmd_type
= LTTNG_REGISTER_CONSUMER
;
521 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
522 sizeof(lsm
.session
.name
));
523 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
525 lttng_ctl_copy_string(lsm
.u
.reg
.path
, socket_path
, sizeof(lsm
.u
.reg
.path
));
527 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
531 * Start tracing for all traces of the session.
532 * Returns size of returned session payload data or a negative error code.
534 int lttng_start_tracing(const char *session_name
)
536 struct lttcomm_session_msg lsm
;
538 if (session_name
== NULL
) {
539 return -LTTNG_ERR_INVALID
;
542 lsm
.cmd_type
= LTTNG_START_TRACE
;
544 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
545 sizeof(lsm
.session
.name
));
547 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
551 * Stop tracing for all traces of the session.
553 static int _lttng_stop_tracing(const char *session_name
, int wait
)
556 struct lttcomm_session_msg lsm
;
558 if (session_name
== NULL
) {
559 return -LTTNG_ERR_INVALID
;
562 lsm
.cmd_type
= LTTNG_STOP_TRACE
;
564 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
565 sizeof(lsm
.session
.name
));
567 ret
= lttng_ctl_ask_sessiond(&lsm
, NULL
);
568 if (ret
< 0 && ret
!= -LTTNG_ERR_TRACE_ALREADY_STOPPED
) {
576 _MSG("Waiting for data availability");
579 /* Check for data availability */
581 data_ret
= lttng_data_pending(session_name
);
583 /* Return the data available call error. */
589 * Data sleep time before retrying (in usec). Don't sleep if the call
590 * returned value indicates availability.
593 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME
);
597 } while (data_ret
!= 0);
607 * Stop tracing and wait for data availability.
609 int lttng_stop_tracing(const char *session_name
)
611 return _lttng_stop_tracing(session_name
, 1);
615 * Stop tracing but _don't_ wait for data availability.
617 int lttng_stop_tracing_no_wait(const char *session_name
)
619 return _lttng_stop_tracing(session_name
, 0);
623 * Add context to a channel.
625 * If the given channel is NULL, add the contexts to all channels.
626 * The event_name param is ignored.
628 * Returns the size of the returned payload data or a negative error code.
630 int lttng_add_context(struct lttng_handle
*handle
,
631 struct lttng_event_context
*ctx
, const char *event_name
,
632 const char *channel_name
)
634 struct lttcomm_session_msg lsm
;
636 /* Safety check. Both are mandatory */
637 if (handle
== NULL
|| ctx
== NULL
) {
638 return -LTTNG_ERR_INVALID
;
641 memset(&lsm
, 0, sizeof(lsm
));
643 lsm
.cmd_type
= LTTNG_ADD_CONTEXT
;
645 /* If no channel name, send empty string. */
646 if (channel_name
== NULL
) {
647 lttng_ctl_copy_string(lsm
.u
.context
.channel_name
, "",
648 sizeof(lsm
.u
.context
.channel_name
));
650 lttng_ctl_copy_string(lsm
.u
.context
.channel_name
, channel_name
,
651 sizeof(lsm
.u
.context
.channel_name
));
654 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
656 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
658 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
659 sizeof(lsm
.session
.name
));
661 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
665 * Enable event(s) for a channel.
666 * If no event name is specified, all events are enabled.
667 * If no channel name is specified, the default 'channel0' is used.
668 * Returns size of returned session payload data or a negative error code.
670 int lttng_enable_event(struct lttng_handle
*handle
,
671 struct lttng_event
*ev
, const char *channel_name
)
673 struct lttcomm_session_msg lsm
;
675 if (handle
== NULL
|| ev
== NULL
) {
676 return -LTTNG_ERR_INVALID
;
679 memset(&lsm
, 0, sizeof(lsm
));
681 /* If no channel name, send empty string. */
682 if (channel_name
== NULL
) {
683 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, "",
684 sizeof(lsm
.u
.enable
.channel_name
));
686 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
687 sizeof(lsm
.u
.enable
.channel_name
));
690 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
692 if (ev
->name
[0] != '\0') {
693 lsm
.cmd_type
= LTTNG_ENABLE_EVENT
;
695 lsm
.cmd_type
= LTTNG_ENABLE_ALL_EVENT
;
697 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(lsm
.u
.enable
.event
));
699 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
700 sizeof(lsm
.session
.name
));
702 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
706 * Create or enable an event with a filter expression.
708 * Return negative error value on error.
709 * Return size of returned session payload data if OK.
711 int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
712 struct lttng_event
*event
, const char *channel_name
,
713 const char *filter_expression
)
715 struct lttcomm_session_msg lsm
;
716 struct filter_parser_ctx
*ctx
;
720 if (!filter_expression
) {
722 * Fall back to normal event enabling if no filter
725 return lttng_enable_event(handle
, event
, channel_name
);
729 * Empty filter string will always be rejected by the parser
730 * anyway, so treat this corner-case early to eliminate
731 * lttng_fmemopen error for 0-byte allocation.
733 if (handle
== NULL
|| filter_expression
[0] == '\0') {
734 return -LTTNG_ERR_INVALID
;
738 * casting const to non-const, as the underlying function will
739 * use it in read-only mode.
741 fmem
= lttng_fmemopen((void *) filter_expression
,
742 strlen(filter_expression
), "r");
744 fprintf(stderr
, "Error opening memory as stream\n");
745 return -LTTNG_ERR_FILTER_NOMEM
;
747 ctx
= filter_parser_ctx_alloc(fmem
);
749 fprintf(stderr
, "Error allocating parser\n");
750 ret
= -LTTNG_ERR_FILTER_NOMEM
;
753 ret
= filter_parser_ctx_append_ast(ctx
);
755 fprintf(stderr
, "Parse error\n");
756 ret
= -LTTNG_ERR_FILTER_INVAL
;
759 ret
= filter_visitor_set_parent(ctx
);
761 fprintf(stderr
, "Set parent error\n");
762 ret
= -LTTNG_ERR_FILTER_INVAL
;
766 ret
= filter_visitor_print_xml(ctx
, stdout
, 0);
769 fprintf(stderr
, "XML print error\n");
770 ret
= -LTTNG_ERR_FILTER_INVAL
;
775 dbg_printf("Generating IR... ");
777 ret
= filter_visitor_ir_generate(ctx
);
779 fprintf(stderr
, "Generate IR error\n");
780 ret
= -LTTNG_ERR_FILTER_INVAL
;
783 dbg_printf("done\n");
785 dbg_printf("Validating IR... ");
787 ret
= filter_visitor_ir_check_binary_op_nesting(ctx
);
789 ret
= -LTTNG_ERR_FILTER_INVAL
;
792 dbg_printf("done\n");
794 dbg_printf("Generating bytecode... ");
796 ret
= filter_visitor_bytecode_generate(ctx
);
798 fprintf(stderr
, "Generate bytecode error\n");
799 ret
= -LTTNG_ERR_FILTER_INVAL
;
802 dbg_printf("done\n");
803 dbg_printf("Size of bytecode generated: %u bytes.\n",
804 bytecode_get_len(&ctx
->bytecode
->b
));
806 memset(&lsm
, 0, sizeof(lsm
));
808 lsm
.cmd_type
= LTTNG_ENABLE_EVENT_WITH_FILTER
;
810 /* If no channel name, send empty string. */
811 if (channel_name
== NULL
) {
812 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, "",
813 sizeof(lsm
.u
.enable
.channel_name
));
815 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
816 sizeof(lsm
.u
.enable
.channel_name
));
819 /* Copy event name */
821 memcpy(&lsm
.u
.enable
.event
, event
, sizeof(lsm
.u
.enable
.event
));
824 lsm
.u
.enable
.bytecode_len
= sizeof(ctx
->bytecode
->b
)
825 + bytecode_get_len(&ctx
->bytecode
->b
);
827 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
829 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
830 sizeof(lsm
.session
.name
));
832 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, &ctx
->bytecode
->b
,
833 lsm
.u
.enable
.bytecode_len
, NULL
);
835 filter_bytecode_free(ctx
);
837 filter_parser_ctx_free(ctx
);
838 if (fclose(fmem
) != 0) {
844 filter_bytecode_free(ctx
);
846 filter_parser_ctx_free(ctx
);
848 if (fclose(fmem
) != 0) {
855 * Disable event(s) of a channel and domain.
856 * If no event name is specified, all events are disabled.
857 * If no channel name is specified, the default 'channel0' is used.
858 * Returns size of returned session payload data or a negative error code.
860 int lttng_disable_event(struct lttng_handle
*handle
, const char *name
,
861 const char *channel_name
)
863 struct lttcomm_session_msg lsm
;
865 if (handle
== NULL
) {
866 return -LTTNG_ERR_INVALID
;
869 memset(&lsm
, 0, sizeof(lsm
));
871 /* If no channel name, send empty string. */
872 if (channel_name
== NULL
) {
873 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, "",
874 sizeof(lsm
.u
.disable
.channel_name
));
876 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, channel_name
,
877 sizeof(lsm
.u
.disable
.channel_name
));
880 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
883 lttng_ctl_copy_string(lsm
.u
.disable
.name
, name
,
884 sizeof(lsm
.u
.disable
.name
));
885 lsm
.cmd_type
= LTTNG_DISABLE_EVENT
;
887 lsm
.cmd_type
= LTTNG_DISABLE_ALL_EVENT
;
890 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
891 sizeof(lsm
.session
.name
));
893 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
897 * Enable channel per domain
898 * Returns size of returned session payload data or a negative error code.
900 int lttng_enable_channel(struct lttng_handle
*handle
,
901 struct lttng_channel
*chan
)
903 struct lttcomm_session_msg lsm
;
906 * NULL arguments are forbidden. No default values.
908 if (handle
== NULL
|| chan
== NULL
) {
909 return -LTTNG_ERR_INVALID
;
912 memset(&lsm
, 0, sizeof(lsm
));
914 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(lsm
.u
.channel
.chan
));
916 lsm
.cmd_type
= LTTNG_ENABLE_CHANNEL
;
918 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
920 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
921 sizeof(lsm
.session
.name
));
923 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
927 * All tracing will be stopped for registered events of the channel.
928 * Returns size of returned session payload data or a negative error code.
930 int lttng_disable_channel(struct lttng_handle
*handle
, const char *name
)
932 struct lttcomm_session_msg lsm
;
934 /* Safety check. Both are mandatory */
935 if (handle
== NULL
|| name
== NULL
) {
936 return -LTTNG_ERR_INVALID
;
939 memset(&lsm
, 0, sizeof(lsm
));
941 lsm
.cmd_type
= LTTNG_DISABLE_CHANNEL
;
943 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, name
,
944 sizeof(lsm
.u
.disable
.channel_name
));
946 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
948 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
949 sizeof(lsm
.session
.name
));
951 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
955 * Lists all available tracepoints of domain.
956 * Sets the contents of the events array.
957 * Returns the number of lttng_event entries in events;
958 * on error, returns a negative value.
960 int lttng_list_tracepoints(struct lttng_handle
*handle
,
961 struct lttng_event
**events
)
964 struct lttcomm_session_msg lsm
;
966 if (handle
== NULL
) {
967 return -LTTNG_ERR_INVALID
;
970 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINTS
;
971 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
973 ret
= lttng_ctl_ask_sessiond(&lsm
, (void **) events
);
978 return ret
/ sizeof(struct lttng_event
);
982 * Lists all available tracepoint fields of domain.
983 * Sets the contents of the event field array.
984 * Returns the number of lttng_event_field entries in events;
985 * on error, returns a negative value.
987 int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
988 struct lttng_event_field
**fields
)
991 struct lttcomm_session_msg lsm
;
993 if (handle
== NULL
) {
994 return -LTTNG_ERR_INVALID
;
997 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINT_FIELDS
;
998 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1000 ret
= lttng_ctl_ask_sessiond(&lsm
, (void **) fields
);
1005 return ret
/ sizeof(struct lttng_event_field
);
1009 * Returns a human readable string describing
1010 * the error code (a negative value).
1012 const char *lttng_strerror(int code
)
1014 return error_get_str(code
);
1018 * Create a brand new session using name and url for destination.
1020 * Returns LTTNG_OK on success or a negative error code.
1022 int lttng_create_session(const char *name
, const char *url
)
1026 struct lttcomm_session_msg lsm
;
1027 struct lttng_uri
*uris
= NULL
;
1030 return -LTTNG_ERR_INVALID
;
1033 memset(&lsm
, 0, sizeof(lsm
));
1035 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1036 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1038 /* There should never be a data URL */
1039 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1041 return -LTTNG_ERR_INVALID
;
1044 lsm
.u
.uri
.size
= size
;
1046 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1047 sizeof(struct lttng_uri
) * size
, NULL
);
1054 * Destroy session using name.
1055 * Returns size of returned session payload data or a negative error code.
1057 int lttng_destroy_session(const char *session_name
)
1059 struct lttcomm_session_msg lsm
;
1061 if (session_name
== NULL
) {
1062 return -LTTNG_ERR_INVALID
;
1065 lsm
.cmd_type
= LTTNG_DESTROY_SESSION
;
1067 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1068 sizeof(lsm
.session
.name
));
1070 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
1074 * Ask the session daemon for all available sessions.
1075 * Sets the contents of the sessions array.
1076 * Returns the number of lttng_session entries in sessions;
1077 * on error, returns a negative value.
1079 int lttng_list_sessions(struct lttng_session
**sessions
)
1082 struct lttcomm_session_msg lsm
;
1084 lsm
.cmd_type
= LTTNG_LIST_SESSIONS
;
1085 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) sessions
);
1090 return ret
/ sizeof(struct lttng_session
);
1094 * Ask the session daemon for all available domains of a session.
1095 * Sets the contents of the domains array.
1096 * Returns the number of lttng_domain entries in domains;
1097 * on error, returns a negative value.
1099 int lttng_list_domains(const char *session_name
,
1100 struct lttng_domain
**domains
)
1103 struct lttcomm_session_msg lsm
;
1105 if (session_name
== NULL
) {
1106 return -LTTNG_ERR_INVALID
;
1109 lsm
.cmd_type
= LTTNG_LIST_DOMAINS
;
1111 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1112 sizeof(lsm
.session
.name
));
1114 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) domains
);
1119 return ret
/ sizeof(struct lttng_domain
);
1123 * Ask the session daemon for all available channels of a session.
1124 * Sets the contents of the channels array.
1125 * Returns the number of lttng_channel entries in channels;
1126 * on error, returns a negative value.
1128 int lttng_list_channels(struct lttng_handle
*handle
,
1129 struct lttng_channel
**channels
)
1132 struct lttcomm_session_msg lsm
;
1134 if (handle
== NULL
) {
1135 return -LTTNG_ERR_INVALID
;
1138 lsm
.cmd_type
= LTTNG_LIST_CHANNELS
;
1139 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1140 sizeof(lsm
.session
.name
));
1142 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1144 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) channels
);
1149 return ret
/ sizeof(struct lttng_channel
);
1153 * Ask the session daemon for all available events of a session channel.
1154 * Sets the contents of the events array.
1155 * Returns the number of lttng_event entries in events;
1156 * on error, returns a negative value.
1158 int lttng_list_events(struct lttng_handle
*handle
,
1159 const char *channel_name
, struct lttng_event
**events
)
1162 struct lttcomm_session_msg lsm
;
1164 /* Safety check. An handle and channel name are mandatory */
1165 if (handle
== NULL
|| channel_name
== NULL
) {
1166 return -LTTNG_ERR_INVALID
;
1169 lsm
.cmd_type
= LTTNG_LIST_EVENTS
;
1170 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1171 sizeof(lsm
.session
.name
));
1172 lttng_ctl_copy_string(lsm
.u
.list
.channel_name
, channel_name
,
1173 sizeof(lsm
.u
.list
.channel_name
));
1175 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1177 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) events
);
1182 return ret
/ sizeof(struct lttng_event
);
1186 * Sets the tracing_group variable with name.
1187 * This function allocates memory pointed to by tracing_group.
1188 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1190 int lttng_set_tracing_group(const char *name
)
1193 return -LTTNG_ERR_INVALID
;
1196 if (asprintf(&tracing_group
, "%s", name
) < 0) {
1197 return -LTTNG_ERR_FATAL
;
1204 * Returns size of returned session payload data or a negative error code.
1206 int lttng_calibrate(struct lttng_handle
*handle
,
1207 struct lttng_calibrate
*calibrate
)
1209 struct lttcomm_session_msg lsm
;
1211 /* Safety check. NULL pointer are forbidden */
1212 if (handle
== NULL
|| calibrate
== NULL
) {
1213 return -LTTNG_ERR_INVALID
;
1216 lsm
.cmd_type
= LTTNG_CALIBRATE
;
1217 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1219 memcpy(&lsm
.u
.calibrate
, calibrate
, sizeof(lsm
.u
.calibrate
));
1221 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
1225 * Set default channel attributes.
1226 * If either or both of the arguments are null, attr content is zeroe'd.
1228 void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
1229 struct lttng_channel_attr
*attr
)
1232 if (attr
== NULL
|| domain
== NULL
) {
1236 memset(attr
, 0, sizeof(struct lttng_channel_attr
));
1238 /* Same for all domains. */
1239 attr
->overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1240 attr
->tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
1241 attr
->tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
1243 switch (domain
->type
) {
1244 case LTTNG_DOMAIN_KERNEL
:
1245 attr
->switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
1246 attr
->read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
1247 attr
->subbuf_size
= default_get_kernel_channel_subbuf_size();
1248 attr
->num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
1249 attr
->output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1251 case LTTNG_DOMAIN_UST
:
1252 switch (domain
->buf_type
) {
1253 case LTTNG_BUFFER_PER_UID
:
1254 attr
->subbuf_size
= default_get_ust_uid_channel_subbuf_size();
1255 attr
->num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
1256 attr
->output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
1257 attr
->switch_timer_interval
= DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
1258 attr
->read_timer_interval
= DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
1260 case LTTNG_BUFFER_PER_PID
:
1262 attr
->subbuf_size
= default_get_ust_pid_channel_subbuf_size();
1263 attr
->num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
1264 attr
->output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
1265 attr
->switch_timer_interval
= DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
1266 attr
->read_timer_interval
= DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
1270 /* Default behavior: leave set to 0. */
1276 * Check if session daemon is alive.
1278 * Return 1 if alive or 0 if not.
1279 * On error returns a negative value.
1281 int lttng_session_daemon_alive(void)
1285 ret
= set_session_daemon_path();
1291 if (*sessiond_sock_path
== '\0') {
1293 * No socket path set. Weird error which means the constructor was not
1299 ret
= try_connect_sessiond(sessiond_sock_path
);
1310 * Set URL for a consumer for a session and domain.
1312 * Return 0 on success, else a negative value.
1314 int lttng_set_consumer_url(struct lttng_handle
*handle
,
1315 const char *control_url
, const char *data_url
)
1319 struct lttcomm_session_msg lsm
;
1320 struct lttng_uri
*uris
= NULL
;
1322 if (handle
== NULL
|| (control_url
== NULL
&& data_url
== NULL
)) {
1323 return -LTTNG_ERR_INVALID
;
1326 memset(&lsm
, 0, sizeof(lsm
));
1328 lsm
.cmd_type
= LTTNG_SET_CONSUMER_URI
;
1330 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1331 sizeof(lsm
.session
.name
));
1332 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1334 size
= uri_parse_str_urls(control_url
, data_url
, &uris
);
1336 return -LTTNG_ERR_INVALID
;
1339 lsm
.u
.uri
.size
= size
;
1341 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1342 sizeof(struct lttng_uri
) * size
, NULL
);
1351 int lttng_enable_consumer(struct lttng_handle
*handle
)
1359 int lttng_disable_consumer(struct lttng_handle
*handle
)
1365 * Set health socket path by putting it in the global health_sock_path
1368 * Returns 0 on success or -ENOMEM.
1370 static int set_health_socket_path(void)
1378 if (uid
== 0 || check_tracing_group(tracing_group
)) {
1379 lttng_ctl_copy_string(health_sock_path
,
1380 DEFAULT_GLOBAL_HEALTH_UNIX_SOCK
, sizeof(health_sock_path
));
1385 * With GNU C < 2.1, snprintf returns -1 if the target buffer
1386 * is too small; With GNU C >= 2.1, snprintf returns the
1387 * required size (excluding closing null).
1389 home
= utils_get_home_dir();
1391 /* Fallback in /tmp */
1395 ret
= snprintf(health_sock_path
, sizeof(health_sock_path
),
1396 DEFAULT_HOME_HEALTH_UNIX_SOCK
, home
);
1397 if ((ret
< 0) || (ret
>= sizeof(health_sock_path
))) {
1405 * Check session daemon health for a specific health component.
1407 * Return 0 if health is OK or else 1 if BAD.
1409 * Any other negative value is a lttng error code which can be translated with
1412 int lttng_health_check(enum lttng_health_component c
)
1415 struct lttcomm_health_msg msg
;
1416 struct lttcomm_health_data reply
;
1418 /* Connect to the sesssion daemon */
1419 sock
= lttcomm_connect_unix_sock(health_sock_path
);
1421 ret
= -LTTNG_ERR_NO_SESSIOND
;
1425 msg
.cmd
= LTTNG_HEALTH_CHECK
;
1428 ret
= lttcomm_send_unix_sock(sock
, (void *)&msg
, sizeof(msg
));
1430 ret
= -LTTNG_ERR_FATAL
;
1434 ret
= lttcomm_recv_unix_sock(sock
, (void *)&reply
, sizeof(reply
));
1436 ret
= -LTTNG_ERR_FATAL
;
1440 ret
= reply
.ret_code
;
1446 closeret
= close(sock
);
1455 * This is an extension of create session that is ONLY and SHOULD only be used
1456 * by the lttng command line program. It exists to avoid using URI parsing in
1459 * We need the date and time for the trace path subdirectory for the case where
1460 * the user does NOT define one using either -o or -U. Using the normal
1461 * lttng_create_session API call, we have no clue on the session daemon side if
1462 * the URL was generated automatically by the client or define by the user.
1464 * So this function "wrapper" is hidden from the public API, takes the datetime
1465 * string and appends it if necessary to the URI subdirectory before sending it
1466 * to the session daemon.
1468 * With this extra function, the lttng_create_session call behavior is not
1469 * changed and the timestamp is appended to the URI on the session daemon side
1472 int _lttng_create_session_ext(const char *name
, const char *url
,
1473 const char *datetime
)
1477 struct lttcomm_session_msg lsm
;
1478 struct lttng_uri
*uris
= NULL
;
1480 if (name
== NULL
|| datetime
== NULL
) {
1481 return -LTTNG_ERR_INVALID
;
1484 memset(&lsm
, 0, sizeof(lsm
));
1486 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1487 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1489 /* There should never be a data URL */
1490 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1492 ret
= -LTTNG_ERR_INVALID
;
1496 lsm
.u
.uri
.size
= size
;
1498 if (size
> 0 && uris
[0].dtype
!= LTTNG_DST_PATH
&& strlen(uris
[0].subdir
) == 0) {
1499 /* Don't append datetime if the name was automatically created. */
1500 if (strncmp(name
, DEFAULT_SESSION_NAME
"-",
1501 strlen(DEFAULT_SESSION_NAME
) + 1)) {
1502 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s-%s",
1505 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s", name
);
1508 PERROR("snprintf uri subdir");
1509 ret
= -LTTNG_ERR_FATAL
;
1514 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1515 sizeof(struct lttng_uri
) * size
, NULL
);
1523 * For a given session name, this call checks if the data is ready to be read
1524 * or is still being extracted by the consumer(s) hence not ready to be used by
1527 int lttng_data_pending(const char *session_name
)
1530 struct lttcomm_session_msg lsm
;
1532 if (session_name
== NULL
) {
1533 return -LTTNG_ERR_INVALID
;
1536 lsm
.cmd_type
= LTTNG_DATA_PENDING
;
1538 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1539 sizeof(lsm
.session
.name
));
1541 ret
= lttng_ctl_ask_sessiond(&lsm
, NULL
);
1544 * The lttng_ctl_ask_sessiond function negate the return code if it's not
1545 * LTTNG_OK so getting -1 means that the reply ret_code was 1 thus meaning
1546 * that the data is available. Yes it is hackish but for now this is the
1557 * Create a session exclusively used for snapshot.
1559 * Returns LTTNG_OK on success or a negative error code.
1561 int lttng_create_session_snapshot(const char *name
, const char *snapshot_url
)
1565 struct lttcomm_session_msg lsm
;
1566 struct lttng_uri
*uris
= NULL
;
1569 return -LTTNG_ERR_INVALID
;
1572 memset(&lsm
, 0, sizeof(lsm
));
1574 lsm
.cmd_type
= LTTNG_CREATE_SESSION_SNAPSHOT
;
1575 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1577 size
= uri_parse_str_urls(snapshot_url
, NULL
, &uris
);
1579 return -LTTNG_ERR_INVALID
;
1582 lsm
.u
.uri
.size
= size
;
1584 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1585 sizeof(struct lttng_uri
) * size
, NULL
);
1592 * Create a session exclusively used for live.
1594 * Returns LTTNG_OK on success or a negative error code.
1596 int lttng_create_session_live(const char *name
, const char *url
,
1597 unsigned int timer_interval
)
1601 struct lttcomm_session_msg lsm
;
1602 struct lttng_uri
*uris
= NULL
;
1605 return -LTTNG_ERR_INVALID
;
1608 memset(&lsm
, 0, sizeof(lsm
));
1610 lsm
.cmd_type
= LTTNG_CREATE_SESSION_LIVE
;
1611 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1613 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1615 ret
= -LTTNG_ERR_INVALID
;
1619 /* file:// is not accepted for live session. */
1620 if (uris
[0].dtype
== LTTNG_DST_PATH
) {
1621 ret
= -LTTNG_ERR_INVALID
;
1625 lsm
.u
.session_live
.nb_uri
= size
;
1626 lsm
.u
.session_live
.timer_interval
= timer_interval
;
1628 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1629 sizeof(struct lttng_uri
) * size
, NULL
);
1639 static void __attribute__((constructor
)) init()
1641 /* Set default session group */
1642 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);
1643 /* Set socket for health check */
1644 if (set_health_socket_path()) {
1652 static void __attribute__((destructor
)) lttng_ctl_exit()
1654 free(tracing_group
);