Commit | Line | Data |
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5b74c7b1 DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
82a3637f DG |
6 | * as published by the Free Software Foundation; only version 2 |
7 | * of the License. | |
91d76f53 | 8 | * |
5b74c7b1 DG |
9 | * This program is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
050349bb | 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
5b74c7b1 DG |
12 | * GNU General Public License for more details. |
13 | * | |
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. | |
17 | */ | |
18 | ||
19 | #define _GNU_SOURCE | |
6c9cc2ab | 20 | #include <limits.h> |
5b74c7b1 DG |
21 | #include <stdio.h> |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
a304c14c MD |
24 | #include <sys/stat.h> |
25 | #include <sys/types.h> | |
f6a9efaa | 26 | #include <urcu.h> |
5b74c7b1 | 27 | |
54d01ffb | 28 | #include <lttng-sessiond-comm.h> |
1e307fab | 29 | #include <lttngerr.h> |
a304c14c | 30 | #include <runas.h> |
1e307fab | 31 | |
daf282ab | 32 | #include "../common/hashtable.h" |
5b74c7b1 DG |
33 | #include "session.h" |
34 | ||
8c0faa1d | 35 | /* |
b5541356 | 36 | * NOTES: |
8c0faa1d | 37 | * |
b5541356 DG |
38 | * No ltt_session.lock is taken here because those data structure are widely |
39 | * spread across the lttng-tools code base so before caling functions below | |
40 | * that can read/write a session, the caller MUST acquire the session lock | |
54d01ffb | 41 | * using session_lock() and session_unlock(). |
8c0faa1d | 42 | */ |
8c0faa1d | 43 | |
5b74c7b1 | 44 | /* |
b5541356 | 45 | * Init tracing session list. |
5b74c7b1 | 46 | * |
b5541356 | 47 | * Please see session.h for more explanation and correct usage of the list. |
5b74c7b1 | 48 | */ |
b5541356 DG |
49 | static struct ltt_session_list ltt_session_list = { |
50 | .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), | |
51 | .lock = PTHREAD_MUTEX_INITIALIZER, | |
52 | .count = 0, | |
53 | }; | |
5b74c7b1 DG |
54 | |
55 | /* | |
050349bb | 56 | * Add a ltt_session structure to the global list. |
5b74c7b1 | 57 | * |
050349bb | 58 | * The caller MUST acquire the session list lock before. |
44e96653 | 59 | * Returns the unique identifier for the session. |
5b74c7b1 | 60 | */ |
44e96653 | 61 | static int add_session_list(struct ltt_session *ls) |
5b74c7b1 DG |
62 | { |
63 | cds_list_add(&ls->list, <t_session_list.head); | |
44e96653 | 64 | return ++ltt_session_list.count; |
5b74c7b1 DG |
65 | } |
66 | ||
67 | /* | |
050349bb | 68 | * Delete a ltt_session structure to the global list. |
b5541356 | 69 | * |
050349bb | 70 | * The caller MUST acquire the session list lock before. |
5b74c7b1 DG |
71 | */ |
72 | static void del_session_list(struct ltt_session *ls) | |
73 | { | |
74 | cds_list_del(&ls->list); | |
75 | /* Sanity check */ | |
b5541356 DG |
76 | if (ltt_session_list.count > 0) { |
77 | ltt_session_list.count--; | |
5b74c7b1 DG |
78 | } |
79 | } | |
80 | ||
b5541356 | 81 | /* |
050349bb | 82 | * Return a pointer to the session list. |
b5541356 | 83 | */ |
54d01ffb | 84 | struct ltt_session_list *session_get_list(void) |
b5541356 DG |
85 | { |
86 | return <t_session_list; | |
87 | } | |
88 | ||
89 | /* | |
6c9cc2ab | 90 | * Acquire session list lock |
b5541356 | 91 | */ |
54d01ffb | 92 | void session_lock_list(void) |
b5541356 | 93 | { |
6c9cc2ab | 94 | pthread_mutex_lock(<t_session_list.lock); |
b5541356 DG |
95 | } |
96 | ||
97 | /* | |
6c9cc2ab | 98 | * Release session list lock |
b5541356 | 99 | */ |
54d01ffb | 100 | void session_unlock_list(void) |
b5541356 | 101 | { |
6c9cc2ab | 102 | pthread_mutex_unlock(<t_session_list.lock); |
b5541356 DG |
103 | } |
104 | ||
105 | /* | |
6c9cc2ab | 106 | * Acquire session lock |
b5541356 | 107 | */ |
54d01ffb | 108 | void session_lock(struct ltt_session *session) |
b5541356 | 109 | { |
6c9cc2ab DG |
110 | pthread_mutex_lock(&session->lock); |
111 | } | |
b5541356 | 112 | |
6c9cc2ab DG |
113 | /* |
114 | * Release session lock | |
115 | */ | |
54d01ffb | 116 | void session_unlock(struct ltt_session *session) |
6c9cc2ab DG |
117 | { |
118 | pthread_mutex_unlock(&session->lock); | |
b5541356 DG |
119 | } |
120 | ||
5b74c7b1 | 121 | /* |
74babd95 DG |
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. | |
5b74c7b1 | 125 | */ |
54d01ffb | 126 | struct ltt_session *session_find_by_name(char *name) |
5b74c7b1 | 127 | { |
5b74c7b1 DG |
128 | struct ltt_session *iter; |
129 | ||
5f822d0a DG |
130 | DBG2("Trying to find session by name %s", name); |
131 | ||
5b74c7b1 | 132 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
1b110e1b | 133 | if (strncmp(iter->name, name, NAME_MAX) == 0) { |
74babd95 | 134 | goto found; |
5b74c7b1 DG |
135 | } |
136 | } | |
137 | ||
74babd95 | 138 | iter = NULL; |
5b74c7b1 | 139 | |
74babd95 | 140 | found: |
5b74c7b1 DG |
141 | return iter; |
142 | } | |
143 | ||
144 | /* | |
050349bb | 145 | * Delete session from the session list and free the memory. |
5b74c7b1 | 146 | * |
050349bb | 147 | * Return -1 if no session is found. On success, return 1; |
5b74c7b1 | 148 | */ |
271933a4 | 149 | int session_destroy(struct ltt_session *session) |
5b74c7b1 | 150 | { |
271933a4 DG |
151 | /* Safety check */ |
152 | if (session == NULL) { | |
153 | ERR("Session pointer was null on session destroy"); | |
154 | return LTTCOMM_OK; | |
5b74c7b1 | 155 | } |
271933a4 DG |
156 | |
157 | DBG("Destroying session %s", session->name); | |
158 | del_session_list(session); | |
271933a4 DG |
159 | pthread_mutex_destroy(&session->lock); |
160 | free(session); | |
5b74c7b1 | 161 | |
54d01ffb | 162 | return LTTCOMM_OK; |
5b74c7b1 DG |
163 | } |
164 | ||
165 | /* | |
050349bb | 166 | * Create a brand new session and add it to the session list. |
5b74c7b1 | 167 | */ |
6df2e2c9 | 168 | int session_create(char *name, char *path, uid_t uid, gid_t gid) |
5b74c7b1 | 169 | { |
f3ed775e | 170 | int ret; |
5b74c7b1 | 171 | struct ltt_session *new_session; |
e07ae692 | 172 | |
54d01ffb | 173 | new_session = session_find_by_name(name); |
5b74c7b1 | 174 | if (new_session != NULL) { |
54d01ffb | 175 | ret = LTTCOMM_EXIST_SESS; |
f3ed775e | 176 | goto error_exist; |
5b74c7b1 DG |
177 | } |
178 | ||
179 | /* Allocate session data structure */ | |
ba7f0ae5 | 180 | new_session = zmalloc(sizeof(struct ltt_session)); |
5b74c7b1 | 181 | if (new_session == NULL) { |
ba7f0ae5 | 182 | perror("zmalloc"); |
54d01ffb | 183 | ret = LTTCOMM_FATAL; |
f3ed775e | 184 | goto error_malloc; |
5b74c7b1 DG |
185 | } |
186 | ||
f3ed775e | 187 | /* Define session name */ |
5b74c7b1 | 188 | if (name != NULL) { |
74babd95 | 189 | if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) { |
54d01ffb | 190 | ret = LTTCOMM_FATAL; |
f3ed775e | 191 | goto error_asprintf; |
5b74c7b1 DG |
192 | } |
193 | } else { | |
f3ed775e | 194 | ERR("No session name given"); |
54d01ffb | 195 | ret = LTTCOMM_FATAL; |
f3ed775e DG |
196 | goto error; |
197 | } | |
198 | ||
199 | /* Define session system path */ | |
200 | if (path != NULL) { | |
74babd95 | 201 | if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) { |
54d01ffb | 202 | ret = LTTCOMM_FATAL; |
f3ed775e | 203 | goto error_asprintf; |
5b74c7b1 | 204 | } |
f3ed775e DG |
205 | } else { |
206 | ERR("No session path given"); | |
54d01ffb | 207 | ret = LTTCOMM_FATAL; |
f3ed775e | 208 | goto error; |
5b74c7b1 DG |
209 | } |
210 | ||
1d4b027a DG |
211 | /* Init kernel session */ |
212 | new_session->kernel_session = NULL; | |
f6a9efaa | 213 | new_session->ust_session = NULL; |
1657e9bb | 214 | |
0177d773 DG |
215 | /* Init lock */ |
216 | pthread_mutex_init(&new_session->lock, NULL); | |
5b74c7b1 | 217 | |
6df2e2c9 MD |
218 | new_session->uid = uid; |
219 | new_session->gid = gid; | |
220 | ||
a304c14c MD |
221 | ret = mkdir_recursive_run_as(new_session->path, S_IRWXU | S_IRWXG, |
222 | new_session->uid, new_session->gid); | |
223 | if (ret < 0) { | |
224 | if (ret != -EEXIST) { | |
225 | ERR("Trace directory creation error"); | |
226 | ret = LTTCOMM_CREATE_FAIL; | |
227 | goto error; | |
228 | } | |
229 | } | |
230 | ||
b5541356 | 231 | /* Add new session to the session list */ |
54d01ffb | 232 | session_lock_list(); |
a991f516 | 233 | new_session->id = add_session_list(new_session); |
54d01ffb | 234 | session_unlock_list(); |
b5541356 | 235 | |
6df2e2c9 MD |
236 | DBG("Tracing session %s created in %s with ID %d by UID %d GID %d", |
237 | name, path, new_session->id, | |
238 | new_session->uid, new_session->gid); | |
b082db07 | 239 | |
54d01ffb | 240 | return LTTCOMM_OK; |
5b74c7b1 DG |
241 | |
242 | error: | |
f3ed775e DG |
243 | error_asprintf: |
244 | if (new_session != NULL) { | |
245 | free(new_session); | |
246 | } | |
5b74c7b1 | 247 | |
f3ed775e DG |
248 | error_exist: |
249 | error_malloc: | |
250 | return ret; | |
5b74c7b1 | 251 | } |