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
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <lttng-sessiond-comm.h>
32 #include <lttng-share.h>
33 #include <lttng/lttng.h>
36 /* Socket to session daemon for communication */
37 static int sessiond_socket
;
38 static char sessiond_sock_path
[PATH_MAX
];
41 static char *tracing_group
;
45 * Copy string from src to dst and enforce null terminated byte.
47 static void copy_string(char *dst
, const char *src
, size_t len
)
50 strncpy(dst
, src
, len
);
51 /* Enforce the NULL terminated byte */
59 * Copy domain to lttcomm_session_msg domain.
61 * If domain is unknown, default domain will be the kernel.
63 static void copy_lttng_domain(struct lttng_domain
*dst
, struct lttng_domain
*src
)
67 case LTTNG_DOMAIN_KERNEL
:
68 case LTTNG_DOMAIN_UST
:
69 case LTTNG_DOMAIN_UST_EXEC_NAME
:
70 case LTTNG_DOMAIN_UST_PID
:
71 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN
:
72 memcpy(dst
, src
, sizeof(struct lttng_domain
));
75 dst
->type
= LTTNG_DOMAIN_KERNEL
;
82 * Send lttcomm_session_msg to the session daemon.
84 * On success, return 0
85 * On error, return error code
87 static int send_session_msg(struct lttcomm_session_msg
*lsm
)
96 ret
= lttcomm_send_unix_sock(sessiond_socket
, lsm
,
97 sizeof(struct lttcomm_session_msg
));
104 * Receive data from the sessiond socket.
106 * On success, return 0
107 * On error, return recv() error code
109 static int recv_data_sessiond(void *buf
, size_t len
)
118 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
125 * Check if the specified group name exist.
127 * If yes return 1, else return -1.
129 static int check_tracing_group(const char *grp_name
)
131 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
133 int grp_list_size
, grp_id
, i
;
136 /* Get GID of group 'tracing' */
137 grp_tracing
= getgrnam(grp_name
);
138 if (grp_tracing
== NULL
) {
139 /* NULL means not found also. getgrnam(3) */
146 /* Get number of supplementary group IDs */
147 grp_list_size
= getgroups(0, NULL
);
148 if (grp_list_size
< 0) {
153 /* Alloc group list of the right size */
154 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
155 grp_id
= getgroups(grp_list_size
, grp_list
);
161 for (i
= 0; i
< grp_list_size
; i
++) {
162 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
176 * Try connect to session daemon with sock_path.
178 * Return 0 on success, else -1
180 static int try_connect_sessiond(const char *sock_path
)
184 /* If socket exist, we check if the daemon listens for connect. */
185 ret
= access(sock_path
, F_OK
);
191 ret
= lttcomm_connect_unix_sock(sock_path
);
197 ret
= lttcomm_close_unix_sock(ret
);
199 perror("lttcomm_close_unix_sock");
206 * Set sessiond socket path by putting it in the global sessiond_sock_path
209 static int set_session_daemon_path(void)
212 int in_tgroup
= 0; /* In tracing group */
218 /* Are we in the tracing group ? */
219 in_tgroup
= check_tracing_group(tracing_group
);
224 copy_string(sessiond_sock_path
,
225 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
226 sizeof(sessiond_sock_path
));
227 } else if (in_tgroup
) {
229 copy_string(sessiond_sock_path
,
230 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
231 sizeof(sessiond_sock_path
));
233 ret
= try_connect_sessiond(sessiond_sock_path
);
235 /* Global session daemon not available */
236 if (snprintf(sessiond_sock_path
, sizeof(sessiond_sock_path
),
237 DEFAULT_HOME_CLIENT_UNIX_SOCK
,
238 getenv("HOME")) < 0) {
243 /* Not in tracing group and not root, default */
244 if (snprintf(sessiond_sock_path
, PATH_MAX
,
245 DEFAULT_HOME_CLIENT_UNIX_SOCK
,
246 getenv("HOME")) < 0) {
255 * Connect to the LTTng session daemon.
257 * On success, return 0. On error, return -1.
259 static int connect_sessiond(void)
263 ret
= set_session_daemon_path();
268 /* Connect to the sesssion daemon */
269 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
274 sessiond_socket
= ret
;
281 * Clean disconnect the session daemon.
283 static int disconnect_sessiond(void)
288 ret
= lttcomm_close_unix_sock(sessiond_socket
);
297 * Ask the session daemon a specific command and put the data into buf.
299 * Return size of data (only payload, not header).
301 static int ask_sessiond(struct lttcomm_session_msg
*lsm
, void **buf
)
306 struct lttcomm_lttng_msg llm
;
308 ret
= connect_sessiond();
313 /* Send command to session daemon */
314 ret
= send_session_msg(lsm
);
319 /* Get header from data transmission */
320 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
325 /* Check error code if OK */
326 if (llm
.ret_code
!= LTTCOMM_OK
) {
331 size
= llm
.data_size
;
337 data
= (void*) malloc(size
);
339 /* Get payload data */
340 ret
= recv_data_sessiond(data
, size
);
350 disconnect_sessiond();
355 * Create lttng handle and return pointer.
357 struct lttng_handle
*lttng_create_handle(const char *session_name
,
358 struct lttng_domain
*domain
)
360 struct lttng_handle
*handle
;
362 handle
= malloc(sizeof(struct lttng_handle
));
363 if (handle
== NULL
) {
364 perror("malloc handle");
368 /* Copy session name */
369 copy_string(handle
->session_name
, session_name
,
370 sizeof(handle
->session_name
));
372 /* Copy lttng domain */
373 copy_lttng_domain(&handle
->domain
, domain
);
380 * Destroy handle by free(3) the pointer.
382 void lttng_destroy_handle(struct lttng_handle
*handle
)
390 * Register an outside consumer.
392 int lttng_register_consumer(struct lttng_handle
*handle
,
393 const char *socket_path
)
395 struct lttcomm_session_msg lsm
;
397 lsm
.cmd_type
= LTTNG_REGISTER_CONSUMER
;
398 copy_string(lsm
.session
.name
, handle
->session_name
,
399 sizeof(lsm
.session
.name
));
400 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
402 copy_string(lsm
.u
.reg
.path
, socket_path
, sizeof(lsm
.u
.reg
.path
));
404 return ask_sessiond(&lsm
, NULL
);
408 * Start tracing for all trace of the session.
410 int lttng_start_tracing(struct lttng_handle
*handle
)
412 struct lttcomm_session_msg lsm
;
418 lsm
.cmd_type
= LTTNG_START_TRACE
;
419 copy_string(lsm
.session
.name
, handle
->session_name
,
420 sizeof(lsm
.session
.name
));
422 return ask_sessiond(&lsm
, NULL
);
426 * Stop tracing for all trace of the session.
428 int lttng_stop_tracing(struct lttng_handle
*handle
)
430 struct lttcomm_session_msg lsm
;
432 lsm
.cmd_type
= LTTNG_STOP_TRACE
;
433 copy_string(lsm
.session
.name
, handle
->session_name
,
434 sizeof(lsm
.session
.name
));
436 return ask_sessiond(&lsm
, NULL
);
440 * Add context to event or/and channel.
442 int lttng_add_context(struct lttng_handle
*handle
,
443 struct lttng_event_context
*ctx
, const char *event_name
,
444 const char *channel_name
)
446 struct lttcomm_session_msg lsm
;
452 lsm
.cmd_type
= LTTNG_ADD_CONTEXT
;
454 /* Copy channel name */
455 copy_string(lsm
.u
.context
.channel_name
, channel_name
,
456 sizeof(lsm
.u
.context
.channel_name
));
457 /* Copy event name */
458 copy_string(lsm
.u
.context
.event_name
, event_name
,
459 sizeof(lsm
.u
.context
.event_name
));
461 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
464 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
467 copy_string(lsm
.session
.name
, handle
->session_name
,
468 sizeof(lsm
.session
.name
));
470 return ask_sessiond(&lsm
, NULL
);
476 int lttng_enable_event(struct lttng_handle
*handle
,
477 struct lttng_event
*ev
, const char *channel_name
)
479 struct lttcomm_session_msg lsm
;
485 if (channel_name
== NULL
) {
486 copy_string(lsm
.u
.enable
.channel_name
, DEFAULT_CHANNEL_NAME
,
487 sizeof(lsm
.u
.enable
.channel_name
));
489 copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
490 sizeof(lsm
.u
.enable
.channel_name
));
493 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
496 lsm
.cmd_type
= LTTNG_ENABLE_EVENT
;
497 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(lsm
.u
.enable
.event
));
499 lsm
.cmd_type
= LTTNG_ENABLE_ALL_EVENT
;
502 copy_string(lsm
.session
.name
, handle
->session_name
,
503 sizeof(lsm
.session
.name
));
505 return ask_sessiond(&lsm
, NULL
);
509 * Disable event of a channel and domain.
511 int lttng_disable_event(struct lttng_handle
*handle
, const char *name
,
512 const char *channel_name
)
514 struct lttcomm_session_msg lsm
;
521 copy_string(lsm
.u
.disable
.channel_name
, channel_name
,
522 sizeof(lsm
.u
.disable
.channel_name
));
524 copy_string(lsm
.u
.disable
.channel_name
, DEFAULT_CHANNEL_NAME
,
525 sizeof(lsm
.u
.disable
.channel_name
));
528 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
531 copy_string(lsm
.u
.disable
.name
, name
, sizeof(lsm
.u
.disable
.name
));
532 lsm
.cmd_type
= LTTNG_DISABLE_EVENT
;
534 lsm
.cmd_type
= LTTNG_DISABLE_ALL_EVENT
;
537 copy_string(lsm
.session
.name
, handle
->session_name
,
538 sizeof(lsm
.session
.name
));
540 return ask_sessiond(&lsm
, NULL
);
544 * Enable channel per domain
546 int lttng_enable_channel(struct lttng_handle
*handle
,
547 struct lttng_channel
*chan
)
549 struct lttcomm_session_msg lsm
;
556 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(lsm
.u
.channel
.chan
));
559 lsm
.cmd_type
= LTTNG_ENABLE_CHANNEL
;
561 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
563 copy_string(lsm
.session
.name
, handle
->session_name
,
564 sizeof(lsm
.session
.name
));
566 return ask_sessiond(&lsm
, NULL
);
570 * All tracing will be stopped for registered events of the channel.
572 int lttng_disable_channel(struct lttng_handle
*handle
, const char *name
)
574 struct lttcomm_session_msg lsm
;
581 copy_string(lsm
.u
.disable
.channel_name
, name
,
582 sizeof(lsm
.u
.disable
.channel_name
));
585 lsm
.cmd_type
= LTTNG_DISABLE_CHANNEL
;
587 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
589 copy_string(lsm
.session
.name
, handle
->session_name
,
590 sizeof(lsm
.session
.name
));
592 return ask_sessiond(&lsm
, NULL
);
596 * List all available tracepoints of domain.
598 * Return the size (bytes) of the list and set the events array.
599 * On error, return negative value.
601 int lttng_list_tracepoints(struct lttng_handle
*handle
,
602 struct lttng_event
**events
)
605 struct lttcomm_session_msg lsm
;
611 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINTS
;
612 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
614 ret
= ask_sessiond(&lsm
, (void **) events
);
619 return ret
/ sizeof(struct lttng_event
);
623 * Return a human readable string of code
625 const char *lttng_get_readable_code(int code
)
627 if (code
> -LTTCOMM_OK
) {
628 return "Ended with errors";
631 return lttcomm_get_readable_code(code
);
635 * Create a brand new session using name.
637 int lttng_create_session(const char *name
, const char *path
)
639 struct lttcomm_session_msg lsm
;
641 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
642 copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
643 copy_string(lsm
.session
.path
, path
, sizeof(lsm
.session
.path
));
645 return ask_sessiond(&lsm
, NULL
);
649 * Destroy session using name.
651 int lttng_destroy_session(struct lttng_handle
*handle
)
653 struct lttcomm_session_msg lsm
;
659 lsm
.cmd_type
= LTTNG_DESTROY_SESSION
;
660 copy_string(lsm
.session
.name
, handle
->session_name
,
661 sizeof(lsm
.session
.name
));
663 return ask_sessiond(&lsm
, NULL
);
667 * Ask the session daemon for all available sessions.
669 * Return number of session.
670 * On error, return negative value.
672 int lttng_list_sessions(struct lttng_session
**sessions
)
675 struct lttcomm_session_msg lsm
;
677 lsm
.cmd_type
= LTTNG_LIST_SESSIONS
;
678 ret
= ask_sessiond(&lsm
, (void**) sessions
);
683 return ret
/ sizeof(struct lttng_session
);
687 * List domain of a session.
689 int lttng_list_domains(struct lttng_handle
*handle
,
690 struct lttng_domain
**domains
)
693 struct lttcomm_session_msg lsm
;
699 lsm
.cmd_type
= LTTNG_LIST_DOMAINS
;
701 copy_string(lsm
.session
.name
, handle
->session_name
,
702 sizeof(lsm
.session
.name
));
704 ret
= ask_sessiond(&lsm
, (void**) domains
);
709 return ret
/ sizeof(struct lttng_domain
);
713 * List channels of a session
715 int lttng_list_channels(struct lttng_handle
*handle
,
716 struct lttng_channel
**channels
)
719 struct lttcomm_session_msg lsm
;
725 lsm
.cmd_type
= LTTNG_LIST_CHANNELS
;
726 copy_string(lsm
.session
.name
, handle
->session_name
,
727 sizeof(lsm
.session
.name
));
729 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
731 ret
= ask_sessiond(&lsm
, (void**) channels
);
736 return ret
/ sizeof(struct lttng_channel
);
740 * List events of a session channel.
742 int lttng_list_events(struct lttng_handle
*handle
,
743 const char *channel_name
, struct lttng_event
**events
)
746 struct lttcomm_session_msg lsm
;
752 lsm
.cmd_type
= LTTNG_LIST_EVENTS
;
753 copy_string(lsm
.session
.name
, handle
->session_name
,
754 sizeof(lsm
.session
.name
));
755 copy_string(lsm
.u
.list
.channel_name
, channel_name
,
756 sizeof(lsm
.u
.list
.channel_name
));
758 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
760 ret
= ask_sessiond(&lsm
, (void**) events
);
765 return ret
/ sizeof(struct lttng_event
);
769 * lttng_set_tracing_group
771 * Set tracing group variable with name. This function
772 * allocate memory pointed by tracing_group.
774 int lttng_set_tracing_group(const char *name
)
776 if (asprintf(&tracing_group
, "%s", name
) < 0) {
786 int lttng_calibrate(struct lttng_handle
*handle
,
787 struct lttng_calibrate
*calibrate
)
789 struct lttcomm_session_msg lsm
;
795 lsm
.cmd_type
= LTTNG_CALIBRATE
;
796 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
798 memcpy(&lsm
.u
.calibrate
, calibrate
, sizeof(lsm
.u
.calibrate
));
800 return ask_sessiond(&lsm
, NULL
);
804 * Check if session daemon is alive.
806 * Return 1 if alive or 0 if not.
809 int lttng_session_daemon_alive(void)
813 ret
= set_session_daemon_path();
819 if (strlen(sessiond_sock_path
) == 0) {
820 /* No socket path set. Weird error */
824 ret
= try_connect_sessiond(sessiond_sock_path
);
837 static void __attribute__((constructor
)) init()
839 /* Set default session group */
840 lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP
);