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 * Start tracing for all trace of the session.
284 int lttng_start_tracing(const char *session_name
)
286 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
287 return ask_sessiond(LTTNG_START_TRACE
, NULL
);
291 * Stop tracing for all trace of the session.
293 int lttng_stop_tracing(const char *session_name
)
295 strncpy(lsm
.session_name
, session_name
, NAME_MAX
);
296 return ask_sessiond(LTTNG_STOP_TRACE
, NULL
);
302 int lttng_add_context(struct lttng_domain
*domain
,
303 struct lttng_event_context
*ctx
, const char *event_name
,
304 const char *channel_name
)
308 if (channel_name
!= NULL
) {
309 strncpy(lsm
.u
.context
.channel_name
, channel_name
, NAME_MAX
);
312 if (event_name
!= NULL
) {
313 strncpy(lsm
.u
.context
.event_name
, event_name
, NAME_MAX
);
316 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
318 switch (domain
->type
) {
319 case LTTNG_DOMAIN_KERNEL
:
320 ret
= ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT
, NULL
);
322 case LTTNG_DOMAIN_UST
:
323 ret
= LTTCOMM_NOT_IMPLEMENTED
;
326 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
336 int lttng_enable_event(struct lttng_domain
*domain
,
337 struct lttng_event
*ev
, const char *channel_name
)
341 if (channel_name
== NULL
) {
342 strncpy(lsm
.u
.enable
.channel_name
, DEFAULT_CHANNEL_NAME
, NAME_MAX
);
344 strncpy(lsm
.u
.enable
.channel_name
, channel_name
, NAME_MAX
);
347 switch (domain
->type
) {
348 case LTTNG_DOMAIN_KERNEL
:
350 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT
, NULL
);
352 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(struct lttng_event
));
353 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT
, NULL
);
356 case LTTNG_DOMAIN_UST
:
357 ret
= LTTCOMM_NOT_IMPLEMENTED
;
360 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
368 * Disable an event in the kernel tracer.
370 int lttng_disable_event(struct lttng_domain
*domain
, const char *name
,
371 const char *channel_name
)
375 if (channel_name
== NULL
) {
376 strncpy(lsm
.u
.disable
.channel_name
, DEFAULT_CHANNEL_NAME
, NAME_MAX
);
378 strncpy(lsm
.u
.disable
.channel_name
, channel_name
, NAME_MAX
);
381 switch (domain
->type
) {
382 case LTTNG_DOMAIN_KERNEL
:
384 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT
, NULL
);
386 strncpy(lsm
.u
.disable
.name
, name
, NAME_MAX
);
387 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT
, NULL
);
390 case LTTNG_DOMAIN_UST
:
391 ret
= LTTCOMM_NOT_IMPLEMENTED
;
394 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
402 * Enable recording for a channel for the kernel tracer.
404 int lttng_enable_channel(struct lttng_domain
*domain
,
405 struct lttng_channel
*chan
)
409 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(struct lttng_channel
));
411 switch (domain
->type
) {
412 case LTTNG_DOMAIN_KERNEL
:
413 ret
= ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL
, NULL
);
415 case LTTNG_DOMAIN_UST
:
416 ret
= LTTCOMM_NOT_IMPLEMENTED
;
419 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
427 * Disable recording for the channel for the kernel tracer.
429 int lttng_disable_channel(struct lttng_domain
*domain
, const char *name
)
433 strncpy(lsm
.u
.disable
.channel_name
, name
, NAME_MAX
);
435 switch (domain
->type
) {
436 case LTTNG_DOMAIN_KERNEL
:
437 ret
= ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL
, NULL
);
439 case LTTNG_DOMAIN_UST
:
440 ret
= LTTCOMM_NOT_IMPLEMENTED
;
443 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
451 * List all available events in the kernel.
453 * Return the size (bytes) of the list and set the event_list array.
454 * On error, return negative value.
456 int lttng_list_events(struct lttng_domain
*domain
, char **event_list
)
460 switch (domain
->type
) {
461 case LTTNG_DOMAIN_KERNEL
:
462 ret
= ask_sessiond(LTTNG_KERNEL_LIST_EVENTS
, (void **) event_list
);
464 case LTTNG_DOMAIN_UST
:
465 ret
= LTTCOMM_NOT_IMPLEMENTED
;
468 ret
= LTTCOMM_UNKNOWN_DOMAIN
;
476 * Return a human readable string of code
478 const char *lttng_get_readable_code(int code
)
480 if (code
> -LTTCOMM_OK
) {
481 return "Ended with errors";
484 return lttcomm_get_readable_code(code
);
488 * Create a brand new session using name.
490 int lttng_create_session(const char *name
, const char *path
)
492 strncpy(lsm
.session_name
, name
, NAME_MAX
);
493 strncpy(lsm
.path
, path
, PATH_MAX
);
494 return ask_sessiond(LTTNG_CREATE_SESSION
, NULL
);
498 * Destroy session using name.
500 int lttng_destroy_session(const char *name
)
502 strncpy(lsm
.session_name
, name
, NAME_MAX
);
503 return ask_sessiond(LTTNG_DESTROY_SESSION
, NULL
);
507 * Ask the session daemon for all available sessions.
509 * Return number of session.
510 * On error, return negative value.
512 int lttng_list_sessions(struct lttng_session
**sessions
)
516 ret
= ask_sessiond(LTTNG_LIST_SESSIONS
, (void**) sessions
);
521 return ret
/ sizeof(struct lttng_session
);
525 * Set session name for the current lsm.
527 void lttng_set_session_name(const char *name
)
529 strncpy(lsm
.session_name
, name
, NAME_MAX
);
533 * lttng_set_tracing_group
535 * Set tracing group variable with name. This function
536 * allocate memory pointed by tracing_group.
538 int lttng_set_tracing_group(const char *name
)
540 if (asprintf(&tracing_group
, "%s", name
) < 0) {
548 * lttng_check_session_daemon
552 * Error, return negative value
554 int lttng_session_daemon_alive(void)
558 ret
= set_session_daemon_path();
564 /* If socket exist, we consider the daemon started */
565 ret
= access(sessiond_sock_path
, F_OK
);
578 static void __attribute__((constructor
)) init()
580 /* Set default session group */
581 lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP
);