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_command_type 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_command_type 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
.size_payload
;
144 data
= (void*) malloc(size
);
146 /* Get payload data */
147 ret
= recv_data_sessiond(data
, size
);
156 lttng_disconnect_sessiond();
157 memset(&lsm
, 0, sizeof(lsm
));
162 * lttng_get_readable_code
164 * Return a human readable string of code
166 const char *lttng_get_readable_code(int code
)
168 if (code
> -LTTCOMM_OK
) {
169 return "Ended with errors";
172 return lttcomm_get_readable_code(code
);
176 * lttng_ust_start_trace
178 * Request a trace start for pid.
180 int lttng_ust_start_trace(pid_t pid
)
185 ret
= ask_sessiond(UST_START_TRACE
, NULL
);
191 * lttng_ust_stop_trace
193 * Request a trace stop for pid.
195 int lttng_ust_stop_trace(pid_t pid
)
200 ret
= ask_sessiond(UST_STOP_TRACE
, NULL
);
206 * lttng_ust_create_trace
208 * Request a trace creation for pid.
210 int lttng_ust_create_trace(pid_t pid
)
215 ret
= ask_sessiond(UST_CREATE_TRACE
, NULL
);
221 * lttng_ust_list_apps
223 * Ask the session daemon for all UST traceable
226 * Return the number of pids.
227 * On error, return negative value.
229 int lttng_ust_list_apps(pid_t
**pids
)
233 ret
= ask_sessiond(UST_LIST_APPS
, (void**) pids
);
238 return ret
/ sizeof(pid_t
);
244 * Ask the session daemon for all traces (kernel and ust)
245 * for the session identified by uuid.
247 * Return the number of traces.
249 int lttng_list_traces(uuid_t
*uuid
, struct lttng_trace
**traces
)
253 uuid_copy(lsm
.session_id
, *uuid
);
255 ret
= ask_sessiond(LTTNG_LIST_TRACES
, (void **) traces
);
260 return ret
/ sizeof(struct lttng_trace
);
264 * lttng_create_session
266 * Create a brand new session using name. Allocate
267 * the session_id param pointing to the UUID.
269 int lttng_create_session(char *name
, uuid_t
*session_id
)
273 strncpy(lsm
.session_name
, name
, sizeof(lsm
.session_name
));
274 lsm
.session_name
[sizeof(lsm
.session_name
) - 1] = '\0';
276 ret
= ask_sessiond(LTTNG_CREATE_SESSION
, NULL
);
281 uuid_copy(*session_id
, llm
.session_id
);
288 * lttng_destroy_session
290 * Destroy session using name.
292 int lttng_destroy_session(uuid_t
*uuid
)
296 uuid_copy(lsm
.session_id
, *uuid
);
298 ret
= ask_sessiond(LTTNG_DESTROY_SESSION
, NULL
);
308 * lttng_list_sessions
310 * Ask the session daemon for all available sessions.
312 * Return number of session.
313 * On error, return negative value.
315 int lttng_list_sessions(struct lttng_session
**sessions
)
319 ret
= ask_sessiond(LTTNG_LIST_SESSIONS
, (void**) sessions
);
324 return ret
/ sizeof(struct lttng_session
);
328 * lttng_connect_sessiond
330 * Connect to the LTTng session daemon.
331 * On success, return 0
332 * On error, return a negative value
334 int lttng_connect_sessiond(void)
338 ret
= set_session_daemon_path();
343 /* Connect to the sesssion daemon */
344 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
349 sessiond_socket
= ret
;
356 * lttng_disconnect_sessiond
358 * Clean disconnect the session daemon.
360 int lttng_disconnect_sessiond(void)
365 ret
= lttcomm_close_unix_sock(sessiond_socket
);
374 * lttng_set_current_session_uuid
376 * Set the session uuid for current lsm.
378 void lttng_set_current_session_uuid(uuid_t
*uuid
)
380 uuid_copy(lsm
.session_id
, *uuid
);
384 * lttng_set_tracing_group
386 * Set tracing group variable with name. This function
387 * allocate memory pointed by tracing_group.
389 int lttng_set_tracing_group(const char *name
)
391 if (asprintf(&tracing_group
, "%s", name
) < 0) {
399 * lttng_check_session_daemon
401 * Return 0 if a sesssion daemon is available
404 int lttng_check_session_daemon(void)
408 ret
= set_session_daemon_path();
413 /* If socket exist, we consider the daemon started */
414 ret
= access(sessiond_sock_path
, F_OK
);
423 * set_session_daemon_path
425 * Set sessiond socket path by putting it in
426 * the global sessiond_sock_path variable.
428 static int set_session_daemon_path(void)
432 /* Are we in the tracing group ? */
433 ret
= check_tracing_group(tracing_group
);
435 if (sprintf(sessiond_sock_path
, DEFAULT_HOME_CLIENT_UNIX_SOCK
,
436 getenv("HOME")) < 0) {
440 strncpy(sessiond_sock_path
, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
441 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
));
448 * check_tracing_group
450 * Check if the specified group name exist.
453 static int check_tracing_group(const char *grp_name
)
455 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
457 int grp_list_size
, grp_id
, i
;
460 /* Get GID of group 'tracing' */
461 grp_tracing
= getgrnam(grp_name
);
462 if (grp_tracing
== NULL
) {
463 /* NULL means not found also. getgrnam(3) */
470 /* Get number of supplementary group IDs */
471 grp_list_size
= getgroups(0, NULL
);
472 if (grp_list_size
< 0) {
477 /* Alloc group list of the right size */
478 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
479 grp_id
= getgroups(grp_list_size
, grp_list
);
485 for (i
= 0; i
< grp_list_size
; i
++) {
486 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
502 static void __attribute__((constructor
)) init()
504 /* Set default session group */
505 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);