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, | |
48 | .count = 0, | |
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); | |
44e96653 | 60 | return ++ltt_session_list.count; |
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. |
e74ecf5a MD |
67 | * The session list count CANNOT be decremented, as it is used as unique |
68 | * identifier for the session in UST app hash table lookups. | |
5b74c7b1 DG |
69 | */ |
70 | static void del_session_list(struct ltt_session *ls) | |
71 | { | |
72 | cds_list_del(&ls->list); | |
5b74c7b1 DG |
73 | } |
74 | ||
b5541356 | 75 | /* |
050349bb | 76 | * Return a pointer to the session list. |
b5541356 | 77 | */ |
54d01ffb | 78 | struct ltt_session_list *session_get_list(void) |
b5541356 DG |
79 | { |
80 | return <t_session_list; | |
81 | } | |
82 | ||
83 | /* | |
6c9cc2ab | 84 | * Acquire session list lock |
b5541356 | 85 | */ |
54d01ffb | 86 | void session_lock_list(void) |
b5541356 | 87 | { |
6c9cc2ab | 88 | pthread_mutex_lock(<t_session_list.lock); |
b5541356 DG |
89 | } |
90 | ||
91 | /* | |
6c9cc2ab | 92 | * Release session list lock |
b5541356 | 93 | */ |
54d01ffb | 94 | void session_unlock_list(void) |
b5541356 | 95 | { |
6c9cc2ab | 96 | pthread_mutex_unlock(<t_session_list.lock); |
b5541356 DG |
97 | } |
98 | ||
99 | /* | |
6c9cc2ab | 100 | * Acquire session lock |
b5541356 | 101 | */ |
54d01ffb | 102 | void session_lock(struct ltt_session *session) |
b5541356 | 103 | { |
6c9cc2ab DG |
104 | pthread_mutex_lock(&session->lock); |
105 | } | |
b5541356 | 106 | |
6c9cc2ab DG |
107 | /* |
108 | * Release session lock | |
109 | */ | |
54d01ffb | 110 | void session_unlock(struct ltt_session *session) |
6c9cc2ab DG |
111 | { |
112 | pthread_mutex_unlock(&session->lock); | |
b5541356 DG |
113 | } |
114 | ||
5b74c7b1 | 115 | /* |
74babd95 DG |
116 | * Return a ltt_session structure ptr that matches name. If no session found, |
117 | * NULL is returned. This must be called with the session lock held using | |
118 | * session_lock_list and session_unlock_list. | |
5b74c7b1 | 119 | */ |
54d01ffb | 120 | struct ltt_session *session_find_by_name(char *name) |
5b74c7b1 | 121 | { |
5b74c7b1 DG |
122 | struct ltt_session *iter; |
123 | ||
5f822d0a DG |
124 | DBG2("Trying to find session by name %s", name); |
125 | ||
5b74c7b1 | 126 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
1b110e1b | 127 | if (strncmp(iter->name, name, NAME_MAX) == 0) { |
74babd95 | 128 | goto found; |
5b74c7b1 DG |
129 | } |
130 | } | |
131 | ||
74babd95 | 132 | iter = NULL; |
5b74c7b1 | 133 | |
74babd95 | 134 | found: |
5b74c7b1 DG |
135 | return iter; |
136 | } | |
137 | ||
138 | /* | |
050349bb | 139 | * Delete session from the session list and free the memory. |
5b74c7b1 | 140 | * |
050349bb | 141 | * Return -1 if no session is found. On success, return 1; |
5b74c7b1 | 142 | */ |
271933a4 | 143 | int session_destroy(struct ltt_session *session) |
5b74c7b1 | 144 | { |
271933a4 DG |
145 | /* Safety check */ |
146 | if (session == NULL) { | |
147 | ERR("Session pointer was null on session destroy"); | |
148 | return LTTCOMM_OK; | |
5b74c7b1 | 149 | } |
271933a4 DG |
150 | |
151 | DBG("Destroying session %s", session->name); | |
152 | del_session_list(session); | |
271933a4 DG |
153 | pthread_mutex_destroy(&session->lock); |
154 | free(session); | |
5b74c7b1 | 155 | |
54d01ffb | 156 | return LTTCOMM_OK; |
5b74c7b1 DG |
157 | } |
158 | ||
159 | /* | |
050349bb | 160 | * Create a brand new session and add it to the session list. |
5b74c7b1 | 161 | */ |
6df2e2c9 | 162 | int session_create(char *name, char *path, uid_t uid, gid_t gid) |
5b74c7b1 | 163 | { |
f3ed775e | 164 | int ret; |
5b74c7b1 | 165 | struct ltt_session *new_session; |
e07ae692 | 166 | |
5b74c7b1 | 167 | /* Allocate session data structure */ |
ba7f0ae5 | 168 | new_session = zmalloc(sizeof(struct ltt_session)); |
5b74c7b1 | 169 | if (new_session == NULL) { |
df0f840b | 170 | PERROR("zmalloc"); |
54d01ffb | 171 | ret = LTTCOMM_FATAL; |
f3ed775e | 172 | goto error_malloc; |
5b74c7b1 DG |
173 | } |
174 | ||
f3ed775e | 175 | /* Define session name */ |
5b74c7b1 | 176 | if (name != NULL) { |
74babd95 | 177 | if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) { |
54d01ffb | 178 | ret = LTTCOMM_FATAL; |
f3ed775e | 179 | goto error_asprintf; |
5b74c7b1 DG |
180 | } |
181 | } else { | |
f3ed775e | 182 | ERR("No session name given"); |
54d01ffb | 183 | ret = LTTCOMM_FATAL; |
f3ed775e DG |
184 | goto error; |
185 | } | |
186 | ||
187 | /* Define session system path */ | |
188 | if (path != NULL) { | |
74babd95 | 189 | if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) { |
54d01ffb | 190 | ret = LTTCOMM_FATAL; |
f3ed775e | 191 | goto error_asprintf; |
5b74c7b1 | 192 | } |
f3ed775e DG |
193 | } else { |
194 | ERR("No session path given"); | |
54d01ffb | 195 | ret = LTTCOMM_FATAL; |
f3ed775e | 196 | goto error; |
5b74c7b1 DG |
197 | } |
198 | ||
1d4b027a DG |
199 | /* Init kernel session */ |
200 | new_session->kernel_session = NULL; | |
f6a9efaa | 201 | new_session->ust_session = NULL; |
1657e9bb | 202 | |
0177d773 DG |
203 | /* Init lock */ |
204 | pthread_mutex_init(&new_session->lock, NULL); | |
5b74c7b1 | 205 | |
6df2e2c9 MD |
206 | new_session->uid = uid; |
207 | new_session->gid = gid; | |
208 | ||
00e2e675 DG |
209 | /* Mkdir if we have a valid path length */ |
210 | if (strlen(new_session->path) > 0) { | |
211 | ret = run_as_mkdir_recursive(new_session->path, S_IRWXU | S_IRWXG, | |
212 | new_session->uid, new_session->gid); | |
213 | if (ret < 0) { | |
214 | if (ret != -EEXIST) { | |
215 | ERR("Trace directory creation error"); | |
216 | ret = LTTCOMM_CREATE_DIR_FAIL; | |
217 | goto error; | |
218 | } | |
a304c14c MD |
219 | } |
220 | } | |
221 | ||
b5541356 | 222 | /* Add new session to the session list */ |
54d01ffb | 223 | session_lock_list(); |
a991f516 | 224 | new_session->id = add_session_list(new_session); |
54d01ffb | 225 | session_unlock_list(); |
b5541356 | 226 | |
fc4705fe | 227 | DBG("Tracing session %s created in %s with ID %u by UID %d GID %d", |
6df2e2c9 MD |
228 | name, path, new_session->id, |
229 | new_session->uid, new_session->gid); | |
b082db07 | 230 | |
54d01ffb | 231 | return LTTCOMM_OK; |
5b74c7b1 DG |
232 | |
233 | error: | |
f3ed775e DG |
234 | error_asprintf: |
235 | if (new_session != NULL) { | |
236 | free(new_session); | |
237 | } | |
5b74c7b1 | 238 | |
f3ed775e DG |
239 | error_malloc: |
240 | return ret; | |
5b74c7b1 | 241 | } |