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