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; only version 2
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.
25 #include <sys/types.h>
28 #include <lttng-sessiond-comm.h>
32 #include "hashtable.h"
35 #include "../hashtable/hash.h"
40 * No ltt_session.lock is taken here because those data structure are widely
41 * spread across the lttng-tools code base so before caling functions below
42 * that can read/write a session, the caller MUST acquire the session lock
43 * using session_lock() and session_unlock().
47 * Init tracing session list.
49 * Please see session.h for more explanation and correct usage of the list.
51 static struct ltt_session_list ltt_session_list
= {
52 .head
= CDS_LIST_HEAD_INIT(ltt_session_list
.head
),
53 .lock
= PTHREAD_MUTEX_INITIALIZER
,
58 * Add a ltt_session structure to the global list.
60 * The caller MUST acquire the session list lock before.
61 * Returns the unique identifier for the session.
63 static int add_session_list(struct ltt_session
*ls
)
65 cds_list_add(&ls
->list
, <t_session_list
.head
);
66 return ++ltt_session_list
.count
;
70 * Delete a ltt_session structure to the global list.
72 * The caller MUST acquire the session list lock before.
74 static void del_session_list(struct ltt_session
*ls
)
76 cds_list_del(&ls
->list
);
78 if (ltt_session_list
.count
> 0) {
79 ltt_session_list
.count
--;
84 * Return a pointer to the session list.
86 struct ltt_session_list
*session_get_list(void)
88 return <t_session_list
;
92 * Acquire session list lock
94 void session_lock_list(void)
96 pthread_mutex_lock(<t_session_list
.lock
);
100 * Release session list lock
102 void session_unlock_list(void)
104 pthread_mutex_unlock(<t_session_list
.lock
);
108 * Acquire session lock
110 void session_lock(struct ltt_session
*session
)
112 pthread_mutex_lock(&session
->lock
);
116 * Release session lock
118 void session_unlock(struct ltt_session
*session
)
120 pthread_mutex_unlock(&session
->lock
);
124 * Return a ltt_session structure ptr that matches name. If no session found,
125 * NULL is returned. This must be called with the session lock held using
126 * session_lock_list and session_unlock_list.
128 struct ltt_session
*session_find_by_name(char *name
)
130 struct ltt_session
*iter
;
132 DBG2("Trying to find session by name %s", name
);
134 cds_list_for_each_entry(iter
, <t_session_list
.head
, list
) {
135 if (strncmp(iter
->name
, name
, NAME_MAX
) == 0) {
147 * Delete session from the session list and free the memory.
149 * Return -1 if no session is found. On success, return 1;
151 int session_destroy(struct ltt_session
*session
)
154 if (session
== NULL
) {
155 ERR("Session pointer was null on session destroy");
159 DBG("Destroying session %s", session
->name
);
160 del_session_list(session
);
161 pthread_mutex_destroy(&session
->lock
);
168 * Create a brand new session and add it to the session list.
170 int session_create(char *name
, char *path
, uid_t uid
, gid_t gid
)
173 struct ltt_session
*new_session
;
175 new_session
= session_find_by_name(name
);
176 if (new_session
!= NULL
) {
177 ret
= LTTCOMM_EXIST_SESS
;
181 /* Allocate session data structure */
182 new_session
= zmalloc(sizeof(struct ltt_session
));
183 if (new_session
== NULL
) {
189 /* Define session name */
191 if (snprintf(new_session
->name
, NAME_MAX
, "%s", name
) < 0) {
196 ERR("No session name given");
201 /* Define session system path */
203 if (snprintf(new_session
->path
, PATH_MAX
, "%s", path
) < 0) {
208 ERR("No session path given");
213 /* Init kernel session */
214 new_session
->kernel_session
= NULL
;
215 new_session
->ust_session
= NULL
;
218 pthread_mutex_init(&new_session
->lock
, NULL
);
220 new_session
->uid
= uid
;
221 new_session
->gid
= gid
;
223 ret
= mkdir_recursive_run_as(new_session
->path
, S_IRWXU
| S_IRWXG
,
224 new_session
->uid
, new_session
->gid
);
226 if (ret
!= -EEXIST
) {
227 ERR("Trace directory creation error");
228 ret
= LTTCOMM_CREATE_FAIL
;
233 /* Add new session to the session list */
235 new_session
->id
= add_session_list(new_session
);
236 session_unlock_list();
238 DBG("Tracing session %s created in %s with ID %d by UID %d GID %d",
239 name
, path
, new_session
->id
,
240 new_session
->uid
, new_session
->gid
);
246 if (new_session
!= NULL
) {