2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 #include <lttng/lttng.h>
29 #include "liblttsessiondcomm.h"
32 /* Socket to session daemon for communication */
33 static int sessiond_socket
;
34 static char sessiond_sock_path
[PATH_MAX
];
36 /* Communication structure to ltt-sessiond */
37 static struct lttcomm_session_msg lsm
;
38 static struct lttcomm_lttng_msg llm
;
41 static int check_tracing_group(const char *grp_name
);
42 static int ask_sessiond(enum lttcomm_sessiond_command lct
, void **buf
);
43 static int recv_data_sessiond(void *buf
, size_t len
);
44 static int send_data_sessiond(void);
45 static int set_session_daemon_path(void);
48 static char *tracing_group
;
54 * Send lttcomm_session_msg to the session daemon.
56 * On success, return 0
57 * On error, return error code
59 static int send_data_sessiond(void)
68 ret
= lttcomm_send_unix_sock(sessiond_socket
, &lsm
, sizeof(lsm
));
77 * Receive data from the sessiond socket.
79 * On success, return 0
80 * On error, return recv() error code
82 static int recv_data_sessiond(void *buf
, size_t len
)
91 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
103 * Ask the session daemon a specific command
104 * and put the data into buf.
106 * Return size of data (only payload, not header).
108 static int ask_sessiond(enum lttcomm_sessiond_command lct
, void **buf
)
114 ret
= lttng_connect_sessiond();
121 /* Send command to session daemon */
122 ret
= send_data_sessiond();
127 /* Get header from data transmission */
128 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
133 /* Check error code if OK */
134 if (llm
.ret_code
!= LTTCOMM_OK
) {
139 size
= llm
.trace_name_offset
+ llm
.data_size
;
144 data
= (void*) malloc(size
);
146 /* Get payload data */
147 ret
= recv_data_sessiond(data
, size
);
156 lttng_disconnect_sessiond();
161 * BEGIN KERNEL CONTROL
165 * lttng_kernel_enable_event
167 * Enable an event in the kernel tracer.
169 int lttng_kernel_enable_event(char *event_name
)
171 strncpy(lsm
.u
.event
.event_name
, event_name
, NAME_MAX
);
172 return ask_sessiond(KERNEL_ENABLE_EVENT
, NULL
);
176 * lttng_kernel_disable_event
178 * Disable an event in the kernel tracer.
180 int lttng_kernel_disable_event(char *event_name
)
182 strncpy(lsm
.u
.event
.event_name
, event_name
, NAME_MAX
);
183 return ask_sessiond(KERNEL_DISABLE_EVENT
, NULL
);
187 * lttng_kernel_create_session
189 * Create a session in the kernel tracer.
191 int lttng_kernel_create_session(void)
193 return ask_sessiond(KERNEL_CREATE_SESSION
, NULL
);
197 * lttng_kernel_create_channel
199 * Create a channel in the kernel tracer.
201 int lttng_kernel_create_channel(void)
203 return ask_sessiond(KERNEL_CREATE_CHANNEL
, NULL
);
207 * lttng_kernel_start_tracing
209 * Start kernel tracing.
211 int lttng_kernel_start_tracing(void)
213 return ask_sessiond(KERNEL_START_TRACE
, NULL
);
217 * lttng_kernel_stop_tracing
219 * Stop kernel tracing.
221 int lttng_kernel_stop_tracing(void)
223 return ask_sessiond(KERNEL_STOP_TRACE
, NULL
);
231 * lttng_get_readable_code
233 * Return a human readable string of code
235 const char *lttng_get_readable_code(int code
)
237 if (code
> -LTTCOMM_OK
) {
238 return "Ended with errors";
241 return lttcomm_get_readable_code(code
);
245 * lttng_ust_start_trace
247 * Request a trace start for pid.
249 int lttng_ust_start_trace(pid_t pid
)
254 ret
= ask_sessiond(UST_START_TRACE
, NULL
);
260 * lttng_ust_stop_trace
262 * Request a trace stop for pid.
264 int lttng_ust_stop_trace(pid_t pid
)
269 ret
= ask_sessiond(UST_STOP_TRACE
, NULL
);
275 * lttng_ust_create_trace
277 * Request a trace creation for pid.
279 int lttng_ust_create_trace(pid_t pid
)
284 ret
= ask_sessiond(UST_CREATE_TRACE
, NULL
);
290 * lttng_ust_list_apps
292 * Ask the session daemon for all UST traceable
295 * Return the number of pids.
296 * On error, return negative value.
298 int lttng_ust_list_apps(pid_t
**pids
)
302 ret
= ask_sessiond(UST_LIST_APPS
, (void**) pids
);
307 return ret
/ sizeof(pid_t
);
313 * Ask the session daemon for all traces (kernel and ust)
314 * for the session identified by uuid.
316 * Return the number of traces.
318 int lttng_list_traces(uuid_t
*uuid
, struct lttng_trace
**traces
)
322 uuid_copy(lsm
.session_uuid
, *uuid
);
324 ret
= ask_sessiond(LTTNG_LIST_TRACES
, (void **) traces
);
329 return ret
/ sizeof(struct lttng_trace
);
333 * lttng_create_session
335 * Create a brand new session using name.
337 int lttng_create_session(char *name
)
341 strncpy(lsm
.session_name
, name
, sizeof(lsm
.session_name
));
342 lsm
.session_name
[sizeof(lsm
.session_name
) - 1] = '\0';
344 ret
= ask_sessiond(LTTNG_CREATE_SESSION
, NULL
);
354 * lttng_destroy_session
356 * Destroy session using name.
358 int lttng_destroy_session(uuid_t
*uuid
)
362 uuid_copy(lsm
.session_uuid
, *uuid
);
364 ret
= ask_sessiond(LTTNG_DESTROY_SESSION
, NULL
);
374 * lttng_list_sessions
376 * Ask the session daemon for all available sessions.
378 * Return number of session.
379 * On error, return negative value.
381 int lttng_list_sessions(struct lttng_session
**sessions
)
385 ret
= ask_sessiond(LTTNG_LIST_SESSIONS
, (void**) sessions
);
390 return ret
/ sizeof(struct lttng_session
);
394 * lttng_connect_sessiond
396 * Connect to the LTTng session daemon.
397 * On success, return 0
398 * On error, return a negative value
400 int lttng_connect_sessiond(void)
404 ret
= set_session_daemon_path();
409 /* Connect to the sesssion daemon */
410 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
415 sessiond_socket
= ret
;
422 * lttng_disconnect_sessiond
424 * Clean disconnect the session daemon.
426 int lttng_disconnect_sessiond(void)
431 ret
= lttcomm_close_unix_sock(sessiond_socket
);
440 * lttng_set_current_session_uuid
442 * Set the session uuid for current lsm.
444 void lttng_set_current_session_uuid(uuid_t
*uuid
)
446 uuid_copy(lsm
.session_uuid
, *uuid
);
450 * lttng_set_tracing_group
452 * Set tracing group variable with name. This function
453 * allocate memory pointed by tracing_group.
455 int lttng_set_tracing_group(const char *name
)
457 if (asprintf(&tracing_group
, "%s", name
) < 0) {
465 * lttng_check_session_daemon
467 * Return 0 if a sesssion daemon is available
470 int lttng_check_session_daemon(void)
474 ret
= set_session_daemon_path();
479 /* If socket exist, we consider the daemon started */
480 ret
= access(sessiond_sock_path
, F_OK
);
489 * set_session_daemon_path
491 * Set sessiond socket path by putting it in
492 * the global sessiond_sock_path variable.
494 static int set_session_daemon_path(void)
498 /* Are we in the tracing group ? */
499 ret
= check_tracing_group(tracing_group
);
500 if (ret
< 0 && getuid() != 0) {
501 if (sprintf(sessiond_sock_path
, DEFAULT_HOME_CLIENT_UNIX_SOCK
,
502 getenv("HOME")) < 0) {
506 strncpy(sessiond_sock_path
, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
507 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
));
514 * check_tracing_group
516 * Check if the specified group name exist.
519 static int check_tracing_group(const char *grp_name
)
521 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
523 int grp_list_size
, grp_id
, i
;
526 /* Get GID of group 'tracing' */
527 grp_tracing
= getgrnam(grp_name
);
528 if (grp_tracing
== NULL
) {
529 /* NULL means not found also. getgrnam(3) */
536 /* Get number of supplementary group IDs */
537 grp_list_size
= getgroups(0, NULL
);
538 if (grp_list_size
< 0) {
543 /* Alloc group list of the right size */
544 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
545 grp_id
= getgroups(grp_list_size
, grp_list
);
551 for (i
= 0; i
< grp_list_size
; i
++) {
552 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
568 static void __attribute__((constructor
)) init()
570 /* Set default session group */
571 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);