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/lttng.h>
33 #include "liblttsessiondcomm.h"
35 #include "lttng-share.h"
37 /* Socket to session daemon for communication */
38 static int sessiond_socket
;
39 static char sessiond_sock_path
[PATH_MAX
];
41 /* Communication structure to ltt-sessiond */
42 static struct lttcomm_session_msg lsm
;
43 static struct lttcomm_lttng_msg llm
;
46 static char *tracing_group
;
52 * Send lttcomm_session_msg to the session daemon.
54 * On success, return 0
55 * On error, return error code
57 static int send_data_sessiond(void)
66 ret
= lttcomm_send_unix_sock(sessiond_socket
, &lsm
, sizeof(lsm
));
75 * Receive data from the sessiond socket.
77 * On success, return 0
78 * On error, return recv() error code
80 static int recv_data_sessiond(void *buf
, size_t len
)
89 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
96 * Check if the specified group name exist.
98 * If yes return 0, else return -1.
100 static int check_tracing_group(const char *grp_name
)
102 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
104 int grp_list_size
, grp_id
, i
;
107 /* Get GID of group 'tracing' */
108 grp_tracing
= getgrnam(grp_name
);
109 if (grp_tracing
== NULL
) {
110 /* NULL means not found also. getgrnam(3) */
117 /* Get number of supplementary group IDs */
118 grp_list_size
= getgroups(0, NULL
);
119 if (grp_list_size
< 0) {
124 /* Alloc group list of the right size */
125 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
126 grp_id
= getgroups(grp_list_size
, grp_list
);
132 for (i
= 0; i
< grp_list_size
; i
++) {
133 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
147 * Set sessiond socket path by putting it in the global sessiond_sock_path
150 static int set_session_daemon_path(void)
154 /* Are we in the tracing group ? */
155 ret
= check_tracing_group(tracing_group
);
156 if (ret
< 0 && getuid() != 0) {
157 if (sprintf(sessiond_sock_path
, DEFAULT_HOME_CLIENT_UNIX_SOCK
,
158 getenv("HOME")) < 0) {
162 strncpy(sessiond_sock_path
, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
163 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
));
170 * Connect to the LTTng session daemon.
172 * On success, return 0. On error, return -1.
174 static int connect_sessiond(void)
178 ret
= set_session_daemon_path();
183 /* Connect to the sesssion daemon */
184 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
189 sessiond_socket
= ret
;
196 * Clean disconnect the session daemon.
198 static int disconnect_sessiond(void)
203 ret
= lttcomm_close_unix_sock(sessiond_socket
);
212 * Reset the session message structure.
214 static void reset_session_msg(void)
216 memset(&lsm
, 0, sizeof(struct lttcomm_session_msg
));
222 * Ask the session daemon a specific command and put the data into buf.
224 * Return size of data (only payload, not header).
226 static int ask_sessiond(enum lttcomm_sessiond_command lct
, void **buf
)
232 ret
= connect_sessiond();
239 /* Send command to session daemon */
240 ret
= send_data_sessiond();
245 /* Get header from data transmission */
246 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
251 /* Check error code if OK */
252 if (llm
.ret_code
!= LTTCOMM_OK
) {
257 size
= llm
.data_size
;
263 data
= (void*) malloc(size
);
265 /* Get payload data */
266 ret
= recv_data_sessiond(data
, size
);
276 disconnect_sessiond();
282 * Copy domain to lttcomm_session_msg domain.
284 * Return -1 if the domain is unkown.
286 static int copy_lttng_domain(struct lttng_domain
*dom
)
289 case LTTNG_DOMAIN_KERNEL
:
290 case LTTNG_DOMAIN_UST
:
291 case LTTNG_DOMAIN_UST_EXEC_NAME
:
292 case LTTNG_DOMAIN_UST_PID
:
293 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN
:
294 memcpy(&lsm
.domain
, dom
, sizeof(struct lttng_domain
));
302 * Start tracing for all trace of the session.
304 int lttng_start_tracing(const char *session_name
)
306 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
307 return ask_sessiond(LTTNG_START_TRACE
, NULL
);
311 * Stop tracing for all trace of the session.
313 int lttng_stop_tracing(const char *session_name
)
315 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
316 return ask_sessiond(LTTNG_STOP_TRACE
, NULL
);
322 int lttng_add_context(struct lttng_domain
*domain
,
323 struct lttng_event_context
*ctx
, const char *event_name
,
324 const char *channel_name
)
328 if (channel_name
!= NULL
) {
329 strncpy(lsm
.u
.context
.channel_name
, channel_name
, NAME_MAX
);
332 if (event_name
!= NULL
) {
333 strncpy(lsm
.u
.context
.event_name
, event_name
, NAME_MAX
);
336 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
338 switch (domain
->type
) {
339 case LTTNG_DOMAIN_KERNEL
:
340 ret
= ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT
, NULL
);
342 case LTTNG_DOMAIN_UST
:
343 ret
= LTTCOMM_NOT_IMPLEMENTED
;
346 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
356 int lttng_enable_event(struct lttng_domain
*domain
,
357 struct lttng_event
*ev
, const char *channel_name
)
361 if (channel_name
== NULL
) {
362 strncpy(lsm
.u
.enable
.channel_name
, DEFAULT_CHANNEL_NAME
, NAME_MAX
);
364 strncpy(lsm
.u
.enable
.channel_name
, channel_name
, NAME_MAX
);
367 switch (domain
->type
) {
368 case LTTNG_DOMAIN_KERNEL
:
370 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT
, NULL
);
372 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(struct lttng_event
));
373 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT
, NULL
);
376 case LTTNG_DOMAIN_UST
:
377 ret
= LTTCOMM_NOT_IMPLEMENTED
;
380 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
388 * Disable an event in the kernel tracer.
390 int lttng_disable_event(struct lttng_domain
*domain
, const char *name
,
391 const char *channel_name
)
395 if (channel_name
== NULL
) {
396 strncpy(lsm
.u
.disable
.channel_name
, DEFAULT_CHANNEL_NAME
, NAME_MAX
);
398 strncpy(lsm
.u
.disable
.channel_name
, channel_name
, NAME_MAX
);
401 switch (domain
->type
) {
402 case LTTNG_DOMAIN_KERNEL
:
404 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT
, NULL
);
406 strncpy(lsm
.u
.disable
.name
, name
, NAME_MAX
);
407 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT
, NULL
);
410 case LTTNG_DOMAIN_UST
:
411 ret
= LTTCOMM_NOT_IMPLEMENTED
;
414 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
422 * Enable recording for a channel for the kernel tracer.
424 int lttng_enable_channel(struct lttng_domain
*domain
,
425 struct lttng_channel
*chan
)
429 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(struct lttng_channel
));
431 switch (domain
->type
) {
432 case LTTNG_DOMAIN_KERNEL
:
433 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL
, NULL
);
435 case LTTNG_DOMAIN_UST
:
436 ret
= LTTCOMM_NOT_IMPLEMENTED
;
439 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
447 * Disable recording for the channel for the kernel tracer.
449 int lttng_disable_channel(struct lttng_domain
*domain
, const char *name
)
453 strncpy(lsm
.u
.disable
.channel_name
, name
, NAME_MAX
);
455 switch (domain
->type
) {
456 case LTTNG_DOMAIN_KERNEL
:
457 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL
, NULL
);
459 case LTTNG_DOMAIN_UST
:
460 ret
= LTTCOMM_NOT_IMPLEMENTED
;
463 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
471 * List all available kernel events.
473 * Return the size (bytes) of the list and set the event_list array.
474 * On error, return negative value.
476 int lttng_list_kernel_events(struct lttng_event
**events
)
480 ret
= ask_sessiond(LTTNG_KERNEL_LIST_EVENTS
, (void **) events
);
482 return ret
/ sizeof(struct lttng_event
);
486 * Return a human readable string of code
488 const char *lttng_get_readable_code(int code
)
490 if (code
> -LTTCOMM_OK
) {
491 return "Ended with errors";
494 return lttcomm_get_readable_code(code
);
498 * Create a brand new session using name.
500 int lttng_create_session(const char *name
, const char *path
)
502 strncpy(lsm
.session_name
, name
, NAME_MAX
);
503 strncpy(lsm
.path
, path
, PATH_MAX
);
504 return ask_sessiond(LTTNG_CREATE_SESSION
, NULL
);
508 * Destroy session using name.
510 int lttng_destroy_session(const char *name
)
512 strncpy(lsm
.session_name
, name
, NAME_MAX
);
513 return ask_sessiond(LTTNG_DESTROY_SESSION
, NULL
);
517 * Ask the session daemon for all available sessions.
519 * Return number of session.
520 * On error, return negative value.
522 int lttng_list_sessions(struct lttng_session
**sessions
)
526 ret
= ask_sessiond(LTTNG_LIST_SESSIONS
, (void**) sessions
);
531 return ret
/ sizeof(struct lttng_session
);
535 * List domain of a session.
537 int lttng_list_domains(const char *session_name
, struct lttng_domain
**domains
)
541 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
542 ret
= ask_sessiond(LTTNG_LIST_DOMAINS
, (void**) domains
);
547 return ret
/ sizeof(struct lttng_domain
);
551 * List channels of a session
553 int lttng_list_channels(struct lttng_domain
*domain
,
554 const char *session_name
, struct lttng_channel
**channels
)
558 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
559 ret
= copy_lttng_domain(domain
);
561 return -LTTCOMM_UNKNOWN_DOMAIN
;
564 ret
= ask_sessiond(LTTNG_LIST_CHANNELS
, (void**) channels
);
569 return ret
/ sizeof(struct lttng_channel
);
573 * List events of a session channel.
575 int lttng_list_events(struct lttng_domain
*domain
,
576 const char *session_name
, const char *channel_name
,
577 struct lttng_event
**events
)
581 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
582 strncpy(lsm
.u
.list
.channel_name
, channel_name
, NAME_MAX
);
583 ret
= copy_lttng_domain(domain
);
585 return -LTTCOMM_UNKNOWN_DOMAIN
;
588 ret
= ask_sessiond(LTTNG_LIST_EVENTS
, (void**) events
);
593 return ret
/ sizeof(struct lttng_event
);
597 * Set session name for the current lsm.
599 void lttng_set_session_name(const char *name
)
601 strncpy(lsm
.session_name
, name
, NAME_MAX
);
605 * lttng_set_tracing_group
607 * Set tracing group variable with name. This function
608 * allocate memory pointed by tracing_group.
610 int lttng_set_tracing_group(const char *name
)
612 if (asprintf(&tracing_group
, "%s", name
) < 0) {
620 * lttng_check_session_daemon
624 * Error, return negative value
626 int lttng_session_daemon_alive(void)
630 ret
= set_session_daemon_path();
636 /* If socket exist, we consider the daemon started */
637 ret
= access(sessiond_sock_path
, F_OK
);
650 static void __attribute__((constructor
)) init()
652 /* Set default session group */
653 lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP
);