Commit | Line | Data |
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5b74c7b1 DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * | |
d14d33bf AM |
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. | |
91d76f53 | 7 | * |
5b74c7b1 DG |
8 | * This program is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
d14d33bf | 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
5b74c7b1 DG |
11 | * GNU General Public License for more details. |
12 | * | |
d14d33bf AM |
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. | |
5b74c7b1 DG |
16 | */ |
17 | ||
18 | #define _GNU_SOURCE | |
6c9cc2ab | 19 | #include <limits.h> |
5b74c7b1 DG |
20 | #include <stdio.h> |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
a304c14c | 23 | #include <sys/stat.h> |
f6a9efaa | 24 | #include <urcu.h> |
5b74c7b1 | 25 | |
990570ed | 26 | #include <common/common.h> |
db758600 | 27 | #include <common/sessiond-comm/sessiond-comm.h> |
1e307fab | 28 | |
5b74c7b1 DG |
29 | #include "session.h" |
30 | ||
8c0faa1d | 31 | /* |
b5541356 | 32 | * NOTES: |
8c0faa1d | 33 | * |
b5541356 DG |
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 | |
54d01ffb | 37 | * using session_lock() and session_unlock(). |
8c0faa1d | 38 | */ |
8c0faa1d | 39 | |
5b74c7b1 | 40 | /* |
b5541356 | 41 | * Init tracing session list. |
5b74c7b1 | 42 | * |
b5541356 | 43 | * Please see session.h for more explanation and correct usage of the list. |
5b74c7b1 | 44 | */ |
b5541356 DG |
45 | static struct ltt_session_list ltt_session_list = { |
46 | .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), | |
47 | .lock = PTHREAD_MUTEX_INITIALIZER, | |
a24f7994 | 48 | .next_uuid = 0, |
b5541356 | 49 | }; |
5b74c7b1 DG |
50 | |
51 | /* | |
050349bb | 52 | * Add a ltt_session structure to the global list. |
5b74c7b1 | 53 | * |
050349bb | 54 | * The caller MUST acquire the session list lock before. |
44e96653 | 55 | * Returns the unique identifier for the session. |
5b74c7b1 | 56 | */ |
fc4705fe | 57 | static unsigned int add_session_list(struct ltt_session *ls) |
5b74c7b1 DG |
58 | { |
59 | cds_list_add(&ls->list, <t_session_list.head); | |
a24f7994 | 60 | return ltt_session_list.next_uuid++; |
5b74c7b1 DG |
61 | } |
62 | ||
63 | /* | |
050349bb | 64 | * Delete a ltt_session structure to the global list. |
b5541356 | 65 | * |
050349bb | 66 | * The caller MUST acquire the session list lock before. |
5b74c7b1 DG |
67 | */ |
68 | static void del_session_list(struct ltt_session *ls) | |
69 | { | |
70 | cds_list_del(&ls->list); | |
5b74c7b1 DG |
71 | } |
72 | ||
b5541356 | 73 | /* |
050349bb | 74 | * Return a pointer to the session list. |
b5541356 | 75 | */ |
54d01ffb | 76 | struct ltt_session_list *session_get_list(void) |
b5541356 DG |
77 | { |
78 | return <t_session_list; | |
79 | } | |
80 | ||
81 | /* | |
6c9cc2ab | 82 | * Acquire session list lock |
b5541356 | 83 | */ |
54d01ffb | 84 | void session_lock_list(void) |
b5541356 | 85 | { |
6c9cc2ab | 86 | pthread_mutex_lock(<t_session_list.lock); |
b5541356 DG |
87 | } |
88 | ||
89 | /* | |
6c9cc2ab | 90 | * Release session list lock |
b5541356 | 91 | */ |
54d01ffb | 92 | void session_unlock_list(void) |
b5541356 | 93 | { |
6c9cc2ab | 94 | pthread_mutex_unlock(<t_session_list.lock); |
b5541356 DG |
95 | } |
96 | ||
97 | /* | |
6c9cc2ab | 98 | * Acquire session lock |
b5541356 | 99 | */ |
54d01ffb | 100 | void session_lock(struct ltt_session *session) |
b5541356 | 101 | { |
6c9cc2ab DG |
102 | pthread_mutex_lock(&session->lock); |
103 | } | |
b5541356 | 104 | |
6c9cc2ab DG |
105 | /* |
106 | * Release session lock | |
107 | */ | |
54d01ffb | 108 | void session_unlock(struct ltt_session *session) |
6c9cc2ab DG |
109 | { |
110 | pthread_mutex_unlock(&session->lock); | |
b5541356 DG |
111 | } |
112 | ||
5b74c7b1 | 113 | /* |
74babd95 DG |
114 | * Return a ltt_session structure ptr that matches name. If no session found, |
115 | * NULL is returned. This must be called with the session lock held using | |
116 | * session_lock_list and session_unlock_list. | |
5b74c7b1 | 117 | */ |
54d01ffb | 118 | struct ltt_session *session_find_by_name(char *name) |
5b74c7b1 | 119 | { |
5b74c7b1 DG |
120 | struct ltt_session *iter; |
121 | ||
5f822d0a DG |
122 | DBG2("Trying to find session by name %s", name); |
123 | ||
5b74c7b1 | 124 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
1b110e1b | 125 | if (strncmp(iter->name, name, NAME_MAX) == 0) { |
74babd95 | 126 | goto found; |
5b74c7b1 DG |
127 | } |
128 | } | |
129 | ||
74babd95 | 130 | iter = NULL; |
5b74c7b1 | 131 | |
74babd95 | 132 | found: |
5b74c7b1 DG |
133 | return iter; |
134 | } | |
135 | ||
136 | /* | |
050349bb | 137 | * Delete session from the session list and free the memory. |
5b74c7b1 | 138 | * |
050349bb | 139 | * Return -1 if no session is found. On success, return 1; |
5b74c7b1 | 140 | */ |
271933a4 | 141 | int session_destroy(struct ltt_session *session) |
5b74c7b1 | 142 | { |
271933a4 DG |
143 | /* Safety check */ |
144 | if (session == NULL) { | |
145 | ERR("Session pointer was null on session destroy"); | |
146 | return LTTCOMM_OK; | |
5b74c7b1 | 147 | } |
271933a4 DG |
148 | |
149 | DBG("Destroying session %s", session->name); | |
150 | del_session_list(session); | |
271933a4 | 151 | pthread_mutex_destroy(&session->lock); |
07424f16 DG |
152 | |
153 | rcu_read_lock(); | |
154 | consumer_destroy_output(session->consumer); | |
155 | rcu_read_unlock(); | |
271933a4 | 156 | free(session); |
5b74c7b1 | 157 | |
54d01ffb | 158 | return LTTCOMM_OK; |
5b74c7b1 DG |
159 | } |
160 | ||
161 | /* | |
050349bb | 162 | * Create a brand new session and add it to the session list. |
5b74c7b1 | 163 | */ |
6df2e2c9 | 164 | int session_create(char *name, char *path, uid_t uid, gid_t gid) |
5b74c7b1 | 165 | { |
f3ed775e | 166 | int ret; |
5b74c7b1 | 167 | struct ltt_session *new_session; |
e07ae692 | 168 | |
5b74c7b1 | 169 | /* Allocate session data structure */ |
ba7f0ae5 | 170 | new_session = zmalloc(sizeof(struct ltt_session)); |
5b74c7b1 | 171 | if (new_session == NULL) { |
df0f840b | 172 | PERROR("zmalloc"); |
54d01ffb | 173 | ret = LTTCOMM_FATAL; |
f3ed775e | 174 | goto error_malloc; |
5b74c7b1 DG |
175 | } |
176 | ||
f3ed775e | 177 | /* Define session name */ |
5b74c7b1 | 178 | if (name != NULL) { |
74babd95 | 179 | if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) { |
54d01ffb | 180 | ret = LTTCOMM_FATAL; |
f3ed775e | 181 | goto error_asprintf; |
5b74c7b1 DG |
182 | } |
183 | } else { | |
f3ed775e | 184 | ERR("No session name given"); |
54d01ffb | 185 | ret = LTTCOMM_FATAL; |
f3ed775e DG |
186 | goto error; |
187 | } | |
188 | ||
189 | /* Define session system path */ | |
190 | if (path != NULL) { | |
74babd95 | 191 | if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) { |
54d01ffb | 192 | ret = LTTCOMM_FATAL; |
f3ed775e | 193 | goto error_asprintf; |
5b74c7b1 | 194 | } |
a4b92340 | 195 | new_session->start_consumer = 1; |
f3ed775e | 196 | } else { |
a4b92340 DG |
197 | /* No path indicates that there is no use for a consumer. */ |
198 | new_session->start_consumer = 0; | |
199 | new_session->path[0] = '\0'; | |
5b74c7b1 DG |
200 | } |
201 | ||
1d4b027a DG |
202 | /* Init kernel session */ |
203 | new_session->kernel_session = NULL; | |
f6a9efaa | 204 | new_session->ust_session = NULL; |
1657e9bb | 205 | |
0177d773 DG |
206 | /* Init lock */ |
207 | pthread_mutex_init(&new_session->lock, NULL); | |
5b74c7b1 | 208 | |
6df2e2c9 MD |
209 | new_session->uid = uid; |
210 | new_session->gid = gid; | |
211 | ||
a4b92340 | 212 | /* Mkdir if we have a valid path and length */ |
00e2e675 DG |
213 | if (strlen(new_session->path) > 0) { |
214 | ret = run_as_mkdir_recursive(new_session->path, S_IRWXU | S_IRWXG, | |
215 | new_session->uid, new_session->gid); | |
216 | if (ret < 0) { | |
217 | if (ret != -EEXIST) { | |
218 | ERR("Trace directory creation error"); | |
219 | ret = LTTCOMM_CREATE_DIR_FAIL; | |
220 | goto error; | |
221 | } | |
a304c14c MD |
222 | } |
223 | } | |
224 | ||
b5541356 | 225 | /* Add new session to the session list */ |
54d01ffb | 226 | session_lock_list(); |
a991f516 | 227 | new_session->id = add_session_list(new_session); |
54d01ffb | 228 | session_unlock_list(); |
b5541356 | 229 | |
a4b92340 DG |
230 | /* |
231 | * Consumer is let to NULL since the create_session_uri command will set it | |
232 | * up and, if valid, assign it to the session. | |
233 | */ | |
234 | ||
235 | DBG("Tracing session %s created in %s with ID %u by UID %d GID %d", name, | |
236 | path, new_session->id, new_session->uid, new_session->gid); | |
b082db07 | 237 | |
54d01ffb | 238 | return LTTCOMM_OK; |
5b74c7b1 DG |
239 | |
240 | error: | |
f3ed775e DG |
241 | error_asprintf: |
242 | if (new_session != NULL) { | |
243 | free(new_session); | |
244 | } | |
5b74c7b1 | 245 | |
f3ed775e DG |
246 | error_malloc: |
247 | return ret; | |
5b74c7b1 | 248 | } |