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/liblttngctl.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
)
116 /* Send command to session daemon */
117 ret
= send_data_sessiond();
122 /* Get header from data transmission */
123 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
128 /* Check error code if OK */
129 if (llm
.ret_code
!= LTTCOMM_OK
) {
134 size
= llm
.size_payload
;
139 data
= (void*) malloc(size
);
141 /* Get payload data */
142 ret
= recv_data_sessiond(data
, size
);
151 /* Reset lsm data struct */
152 memset(&lsm
, 0, sizeof(lsm
));
157 * lttng_get_readable_code
159 * Return a human readable string of code
161 const char *lttng_get_readable_code(int code
)
163 if (code
> -LTTCOMM_OK
) {
164 return "Ended with errors";
167 return lttcomm_get_readable_code(code
);
171 * lttng_ust_list_apps
173 * Ask the session daemon for all UST traceable
176 * Return the number of pids.
177 * On error, return negative value.
179 int lttng_ust_list_apps(pid_t
**pids
)
183 ret
= ask_sessiond(UST_LIST_APPS
, (void**) pids
);
188 return ret
/ sizeof(pid_t
);
192 * lttng_create_session
194 * Create a brand new session using name. Allocate
195 * the session_id param pointing to the UUID.
197 int lttng_create_session(char *name
, char **session_id
)
202 strncpy(lsm
.session_name
, name
, sizeof(lsm
.session_name
));
204 ret
= ask_sessiond(LTTNG_CREATE_SESSION
, NULL
);
209 /* Allocate UUID string length */
210 uuid
= malloc(UUID_STR_LEN
);
212 strncpy(uuid
, llm
.session_id
, UUID_STR_LEN
);
220 * lttng_list_sessions
222 * Ask the session daemon for all available sessions.
224 * Return number of session.
225 * On error, return negative value.
227 int lttng_list_sessions(struct lttng_session
**sessions
)
231 ret
= ask_sessiond(LTTNG_LIST_SESSIONS
, (void**) sessions
);
236 return ret
/ sizeof(struct lttng_session
);
240 * lttng_connect_sessiond
242 * Connect to the LTTng session daemon.
243 * On success, return 0
244 * On error, return a negative value
246 int lttng_connect_sessiond(void)
250 ret
= set_session_daemon_path();
255 /* Connect to the sesssion daemon */
256 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
261 sessiond_socket
= ret
;
268 * lttng_set_tracing_group
270 * Set tracing group variable with name. This function
271 * allocate memory pointed by tracing_group.
273 int lttng_set_tracing_group(const char *name
)
275 if (asprintf(&tracing_group
, "%s", name
) < 0) {
283 * lttng_check_session_daemon
285 * Return 0 if a sesssion daemon is available
288 int lttng_check_session_daemon(void)
292 ret
= set_session_daemon_path();
297 /* If socket exist, we consider the daemon started */
298 ret
= access(sessiond_sock_path
, F_OK
);
307 * set_session_daemon_path
309 * Set sessiond socket path by putting it in
310 * the global sessiond_sock_path variable.
312 static int set_session_daemon_path(void)
316 /* Are we in the tracing group ? */
317 ret
= check_tracing_group(tracing_group
);
319 if (sprintf(sessiond_sock_path
, DEFAULT_HOME_CLIENT_UNIX_SOCK
,
320 getenv("HOME")) < 0) {
324 strncpy(sessiond_sock_path
, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
325 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
));
332 * check_tracing_group
334 * Check if the specified group name exist.
337 static int check_tracing_group(const char *grp_name
)
339 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
341 int grp_list_size
, grp_id
, i
;
344 /* Get GID of group 'tracing' */
345 grp_tracing
= getgrnam(grp_name
);
346 if (grp_tracing
== NULL
) {
347 /* NULL means not found also. getgrnam(3) */
354 /* Get number of supplementary group IDs */
355 grp_list_size
= getgroups(0, NULL
);
356 if (grp_list_size
< 0) {
361 /* Alloc group list of the right size */
362 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
363 grp_id
= getgroups(grp_list_size
, grp_list
);
369 for (i
= 0; i
< grp_list_size
; i
++) {
370 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
386 static void __attribute__((constructor
)) init()
388 /* Set default session group */
389 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);