2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <common/common.h>
27 #include <common/sessiond-comm/sessiond-comm.h>
34 * No ltt_session.lock is taken here because those data structure are widely
35 * spread across the lttng-tools code base so before caling functions below
36 * that can read/write a session, the caller MUST acquire the session lock
37 * using session_lock() and session_unlock().
41 * Init tracing session list.
43 * Please see session.h for more explanation and correct usage of the list.
45 static struct ltt_session_list ltt_session_list
= {
46 .head
= CDS_LIST_HEAD_INIT(ltt_session_list
.head
),
47 .lock
= PTHREAD_MUTEX_INITIALIZER
,
52 * Add a ltt_session structure to the global list.
54 * The caller MUST acquire the session list lock before.
55 * Returns the unique identifier for the session.
57 static unsigned int add_session_list(struct ltt_session
*ls
)
61 cds_list_add(&ls
->list
, <t_session_list
.head
);
62 return ltt_session_list
.next_uuid
++;
66 * Delete a ltt_session structure to the global list.
68 * The caller MUST acquire the session list lock before.
70 static void del_session_list(struct ltt_session
*ls
)
74 cds_list_del(&ls
->list
);
78 * Return a pointer to the session list.
80 struct ltt_session_list
*session_get_list(void)
82 return <t_session_list
;
86 * Acquire session list lock
88 void session_lock_list(void)
90 pthread_mutex_lock(<t_session_list
.lock
);
94 * Release session list lock
96 void session_unlock_list(void)
98 pthread_mutex_unlock(<t_session_list
.lock
);
102 * Acquire session lock
104 void session_lock(struct ltt_session
*session
)
108 pthread_mutex_lock(&session
->lock
);
112 * Release session lock
114 void session_unlock(struct ltt_session
*session
)
118 pthread_mutex_unlock(&session
->lock
);
122 * Return a ltt_session structure ptr that matches name. If no session found,
123 * NULL is returned. This must be called with the session lock held using
124 * session_lock_list and session_unlock_list.
126 struct ltt_session
*session_find_by_name(char *name
)
128 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;
150 * Should *NOT* be called with RCU read-side lock held.
152 int session_destroy(struct ltt_session
*session
)
157 DBG("Destroying session %s", session
->name
);
158 del_session_list(session
);
159 pthread_mutex_destroy(&session
->lock
);
161 consumer_destroy_output(session
->consumer
);
168 * Create a brand new session and add it to the session list.
170 int session_create(char *name
, uid_t uid
, gid_t gid
)
173 struct ltt_session
*new_session
;
175 /* Allocate session data structure */
176 new_session
= zmalloc(sizeof(struct ltt_session
));
177 if (new_session
== NULL
) {
179 ret
= LTTNG_ERR_FATAL
;
183 /* Define session name */
185 if (snprintf(new_session
->name
, NAME_MAX
, "%s", name
) < 0) {
186 ret
= LTTNG_ERR_FATAL
;
190 ERR("No session name given");
191 ret
= LTTNG_ERR_FATAL
;
195 /* Init kernel session */
196 new_session
->kernel_session
= NULL
;
197 new_session
->ust_session
= NULL
;
200 pthread_mutex_init(&new_session
->lock
, NULL
);
202 new_session
->uid
= uid
;
203 new_session
->gid
= gid
;
205 /* Add new session to the session list */
207 new_session
->id
= add_session_list(new_session
);
208 session_unlock_list();
211 * Consumer is let to NULL since the create_session_uri command will set it
212 * up and, if valid, assign it to the session.
215 DBG("Tracing session %s created with ID %u by UID %d GID %d", name
,
216 new_session
->id
, new_session
->uid
, new_session
->gid
);
229 * Check if the UID or GID match the session. Root user has access to all
232 int session_access_ok(struct ltt_session
*session
, uid_t uid
, gid_t gid
)
236 if (uid
!= session
->uid
&& gid
!= session
->gid
&& uid
!= 0) {