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 | ||
6c1c0768 | 18 | #define _LGPL_SOURCE |
6c9cc2ab | 19 | #include <limits.h> |
d022620a | 20 | #include <inttypes.h> |
5b74c7b1 DG |
21 | #include <stdio.h> |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
a304c14c | 24 | #include <sys/stat.h> |
f6a9efaa | 25 | #include <urcu.h> |
3d071855 MD |
26 | #include <dirent.h> |
27 | #include <sys/types.h> | |
5b74c7b1 | 28 | |
990570ed | 29 | #include <common/common.h> |
db758600 | 30 | #include <common/sessiond-comm/sessiond-comm.h> |
1e307fab | 31 | |
5b74c7b1 DG |
32 | #include "session.h" |
33 | ||
8c0faa1d | 34 | /* |
b5541356 | 35 | * NOTES: |
8c0faa1d | 36 | * |
b5541356 DG |
37 | * No ltt_session.lock is taken here because those data structure are widely |
38 | * spread across the lttng-tools code base so before caling functions below | |
39 | * that can read/write a session, the caller MUST acquire the session lock | |
54d01ffb | 40 | * using session_lock() and session_unlock(). |
8c0faa1d | 41 | */ |
8c0faa1d | 42 | |
5b74c7b1 | 43 | /* |
b5541356 | 44 | * Init tracing session list. |
5b74c7b1 | 45 | * |
b5541356 | 46 | * Please see session.h for more explanation and correct usage of the list. |
5b74c7b1 | 47 | */ |
b5541356 DG |
48 | static struct ltt_session_list ltt_session_list = { |
49 | .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), | |
50 | .lock = PTHREAD_MUTEX_INITIALIZER, | |
a24f7994 | 51 | .next_uuid = 0, |
b5541356 | 52 | }; |
5b74c7b1 | 53 | |
1c1c3634 DG |
54 | /* These characters are forbidden in a session name. Used by validate_name. */ |
55 | static const char *forbidden_name_chars = "/"; | |
56 | ||
57 | /* | |
58 | * Validate the session name for forbidden characters. | |
59 | * | |
60 | * Return 0 on success else -1 meaning a forbidden char. has been found. | |
61 | */ | |
62 | static int validate_name(const char *name) | |
63 | { | |
64 | int ret; | |
65 | char *tok, *tmp_name; | |
66 | ||
67 | assert(name); | |
68 | ||
69 | tmp_name = strdup(name); | |
70 | if (!tmp_name) { | |
71 | /* ENOMEM here. */ | |
72 | ret = -1; | |
73 | goto error; | |
74 | } | |
75 | ||
76 | tok = strpbrk(tmp_name, forbidden_name_chars); | |
77 | if (tok) { | |
78 | DBG("Session name %s contains a forbidden character", name); | |
79 | /* Forbidden character has been found. */ | |
80 | ret = -1; | |
81 | goto error; | |
82 | } | |
83 | ret = 0; | |
84 | ||
85 | error: | |
86 | free(tmp_name); | |
87 | return ret; | |
88 | } | |
89 | ||
5b74c7b1 | 90 | /* |
050349bb | 91 | * Add a ltt_session structure to the global list. |
5b74c7b1 | 92 | * |
050349bb | 93 | * The caller MUST acquire the session list lock before. |
44e96653 | 94 | * Returns the unique identifier for the session. |
5b74c7b1 | 95 | */ |
d022620a | 96 | static uint64_t add_session_list(struct ltt_session *ls) |
5b74c7b1 | 97 | { |
0525e9ae DG |
98 | assert(ls); |
99 | ||
5b74c7b1 | 100 | cds_list_add(&ls->list, <t_session_list.head); |
a24f7994 | 101 | return ltt_session_list.next_uuid++; |
5b74c7b1 DG |
102 | } |
103 | ||
104 | /* | |
050349bb | 105 | * Delete a ltt_session structure to the global list. |
b5541356 | 106 | * |
050349bb | 107 | * The caller MUST acquire the session list lock before. |
5b74c7b1 DG |
108 | */ |
109 | static void del_session_list(struct ltt_session *ls) | |
110 | { | |
0525e9ae DG |
111 | assert(ls); |
112 | ||
5b74c7b1 | 113 | cds_list_del(&ls->list); |
5b74c7b1 DG |
114 | } |
115 | ||
b5541356 | 116 | /* |
050349bb | 117 | * Return a pointer to the session list. |
b5541356 | 118 | */ |
54d01ffb | 119 | struct ltt_session_list *session_get_list(void) |
b5541356 DG |
120 | { |
121 | return <t_session_list; | |
122 | } | |
123 | ||
124 | /* | |
6c9cc2ab | 125 | * Acquire session list lock |
b5541356 | 126 | */ |
54d01ffb | 127 | void session_lock_list(void) |
b5541356 | 128 | { |
6c9cc2ab | 129 | pthread_mutex_lock(<t_session_list.lock); |
b5541356 DG |
130 | } |
131 | ||
132 | /* | |
6c9cc2ab | 133 | * Release session list lock |
b5541356 | 134 | */ |
54d01ffb | 135 | void session_unlock_list(void) |
b5541356 | 136 | { |
6c9cc2ab | 137 | pthread_mutex_unlock(<t_session_list.lock); |
b5541356 DG |
138 | } |
139 | ||
140 | /* | |
6c9cc2ab | 141 | * Acquire session lock |
b5541356 | 142 | */ |
54d01ffb | 143 | void session_lock(struct ltt_session *session) |
b5541356 | 144 | { |
0525e9ae DG |
145 | assert(session); |
146 | ||
6c9cc2ab DG |
147 | pthread_mutex_lock(&session->lock); |
148 | } | |
b5541356 | 149 | |
6c9cc2ab DG |
150 | /* |
151 | * Release session lock | |
152 | */ | |
54d01ffb | 153 | void session_unlock(struct ltt_session *session) |
6c9cc2ab | 154 | { |
0525e9ae DG |
155 | assert(session); |
156 | ||
6c9cc2ab | 157 | pthread_mutex_unlock(&session->lock); |
b5541356 DG |
158 | } |
159 | ||
5b74c7b1 | 160 | /* |
74babd95 DG |
161 | * Return a ltt_session structure ptr that matches name. If no session found, |
162 | * NULL is returned. This must be called with the session lock held using | |
163 | * session_lock_list and session_unlock_list. | |
5b74c7b1 | 164 | */ |
58a1a227 | 165 | struct ltt_session *session_find_by_name(const char *name) |
5b74c7b1 | 166 | { |
5b74c7b1 DG |
167 | struct ltt_session *iter; |
168 | ||
0525e9ae DG |
169 | assert(name); |
170 | ||
5f822d0a DG |
171 | DBG2("Trying to find session by name %s", name); |
172 | ||
5b74c7b1 | 173 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
1b110e1b | 174 | if (strncmp(iter->name, name, NAME_MAX) == 0) { |
74babd95 | 175 | goto found; |
5b74c7b1 DG |
176 | } |
177 | } | |
178 | ||
74babd95 | 179 | iter = NULL; |
5b74c7b1 | 180 | |
74babd95 | 181 | found: |
5b74c7b1 DG |
182 | return iter; |
183 | } | |
184 | ||
185 | /* | |
050349bb | 186 | * Delete session from the session list and free the memory. |
5b74c7b1 | 187 | * |
050349bb | 188 | * Return -1 if no session is found. On success, return 1; |
36b588ed | 189 | * Should *NOT* be called with RCU read-side lock held. |
5b74c7b1 | 190 | */ |
271933a4 | 191 | int session_destroy(struct ltt_session *session) |
5b74c7b1 | 192 | { |
271933a4 | 193 | /* Safety check */ |
0525e9ae | 194 | assert(session); |
271933a4 DG |
195 | |
196 | DBG("Destroying session %s", session->name); | |
197 | del_session_list(session); | |
271933a4 | 198 | pthread_mutex_destroy(&session->lock); |
07424f16 | 199 | |
6addfa37 | 200 | consumer_output_put(session->consumer); |
6dc3064a | 201 | snapshot_destroy(&session->snapshot); |
271933a4 | 202 | free(session); |
5b74c7b1 | 203 | |
f73fabfd | 204 | return LTTNG_OK; |
5b74c7b1 DG |
205 | } |
206 | ||
207 | /* | |
050349bb | 208 | * Create a brand new session and add it to the session list. |
5b74c7b1 | 209 | */ |
dec56f6c | 210 | int session_create(char *name, uid_t uid, gid_t gid) |
5b74c7b1 | 211 | { |
f3ed775e | 212 | int ret; |
5b74c7b1 | 213 | struct ltt_session *new_session; |
e07ae692 | 214 | |
5b74c7b1 | 215 | /* Allocate session data structure */ |
ba7f0ae5 | 216 | new_session = zmalloc(sizeof(struct ltt_session)); |
5b74c7b1 | 217 | if (new_session == NULL) { |
df0f840b | 218 | PERROR("zmalloc"); |
f73fabfd | 219 | ret = LTTNG_ERR_FATAL; |
f3ed775e | 220 | goto error_malloc; |
5b74c7b1 DG |
221 | } |
222 | ||
f3ed775e | 223 | /* Define session name */ |
5b74c7b1 | 224 | if (name != NULL) { |
74babd95 | 225 | if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) { |
f73fabfd | 226 | ret = LTTNG_ERR_FATAL; |
f3ed775e | 227 | goto error_asprintf; |
5b74c7b1 DG |
228 | } |
229 | } else { | |
f3ed775e | 230 | ERR("No session name given"); |
f73fabfd | 231 | ret = LTTNG_ERR_FATAL; |
f3ed775e DG |
232 | goto error; |
233 | } | |
234 | ||
1c1c3634 DG |
235 | ret = validate_name(name); |
236 | if (ret < 0) { | |
237 | ret = LTTNG_ERR_SESSION_INVALID_CHAR; | |
238 | goto error; | |
239 | } | |
240 | ||
d3e2ba59 | 241 | ret = gethostname(new_session->hostname, sizeof(new_session->hostname)); |
73184835 DG |
242 | if (ret < 0) { |
243 | if (errno == ENAMETOOLONG) { | |
244 | new_session->hostname[sizeof(new_session->hostname) - 1] = '\0'; | |
245 | } else { | |
246 | ret = LTTNG_ERR_FATAL; | |
247 | goto error; | |
248 | } | |
d3e2ba59 JD |
249 | } |
250 | ||
1d4b027a DG |
251 | /* Init kernel session */ |
252 | new_session->kernel_session = NULL; | |
f6a9efaa | 253 | new_session->ust_session = NULL; |
1657e9bb | 254 | |
0177d773 DG |
255 | /* Init lock */ |
256 | pthread_mutex_init(&new_session->lock, NULL); | |
5b74c7b1 | 257 | |
6df2e2c9 MD |
258 | new_session->uid = uid; |
259 | new_session->gid = gid; | |
260 | ||
6dc3064a DG |
261 | ret = snapshot_init(&new_session->snapshot); |
262 | if (ret < 0) { | |
263 | ret = LTTNG_ERR_NOMEM; | |
264 | goto error; | |
265 | } | |
266 | ||
b5541356 | 267 | /* Add new session to the session list */ |
54d01ffb | 268 | session_lock_list(); |
a991f516 | 269 | new_session->id = add_session_list(new_session); |
54d01ffb | 270 | session_unlock_list(); |
b5541356 | 271 | |
a4b92340 DG |
272 | /* |
273 | * Consumer is let to NULL since the create_session_uri command will set it | |
274 | * up and, if valid, assign it to the session. | |
275 | */ | |
276 | ||
d022620a DG |
277 | DBG("Tracing session %s created with ID %" PRIu64 " by UID %d GID %d", |
278 | name, new_session->id, new_session->uid, new_session->gid); | |
b082db07 | 279 | |
f73fabfd | 280 | return LTTNG_OK; |
5b74c7b1 DG |
281 | |
282 | error: | |
f3ed775e | 283 | error_asprintf: |
0e428499 | 284 | free(new_session); |
5b74c7b1 | 285 | |
f3ed775e DG |
286 | error_malloc: |
287 | return ret; | |
5b74c7b1 | 288 | } |
2f77fc4b DG |
289 | |
290 | /* | |
291 | * Check if the UID or GID match the session. Root user has access to all | |
292 | * sessions. | |
293 | */ | |
294 | int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid) | |
295 | { | |
296 | assert(session); | |
297 | ||
298 | if (uid != session->uid && gid != session->gid && uid != 0) { | |
299 | return 0; | |
300 | } else { | |
301 | return 1; | |
302 | } | |
303 | } |