Fix: notification channel not released on error path
[lttng-tools.git] / src / bin / lttng-sessiond / session.c
CommitLineData
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1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
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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 *
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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
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11 * GNU General Public License for more details.
12 *
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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.
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16 */
17
6c1c0768 18#define _LGPL_SOURCE
6c9cc2ab 19#include <limits.h>
d022620a 20#include <inttypes.h>
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21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
a304c14c 24#include <sys/stat.h>
f6a9efaa 25#include <urcu.h>
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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 32#include "session.h"
23324029 33#include "utils.h"
dd73d57b 34#include "trace-ust.h"
5b74c7b1 35
8c0faa1d 36/*
b5541356 37 * NOTES:
8c0faa1d 38 *
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39 * No ltt_session.lock is taken here because those data structure are widely
40 * spread across the lttng-tools code base so before caling functions below
41 * that can read/write a session, the caller MUST acquire the session lock
54d01ffb 42 * using session_lock() and session_unlock().
8c0faa1d 43 */
8c0faa1d 44
5b74c7b1 45/*
b5541356 46 * Init tracing session list.
5b74c7b1 47 *
b5541356 48 * Please see session.h for more explanation and correct usage of the list.
5b74c7b1 49 */
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50static struct ltt_session_list ltt_session_list = {
51 .head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
52 .lock = PTHREAD_MUTEX_INITIALIZER,
a24f7994 53 .next_uuid = 0,
b5541356 54};
5b74c7b1 55
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56/* These characters are forbidden in a session name. Used by validate_name. */
57static const char *forbidden_name_chars = "/";
58
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59/* Global hash table to keep the sessions, indexed by id. */
60static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
61
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62/*
63 * Validate the session name for forbidden characters.
64 *
65 * Return 0 on success else -1 meaning a forbidden char. has been found.
66 */
67static int validate_name(const char *name)
68{
69 int ret;
70 char *tok, *tmp_name;
71
72 assert(name);
73
74 tmp_name = strdup(name);
75 if (!tmp_name) {
76 /* ENOMEM here. */
77 ret = -1;
78 goto error;
79 }
80
81 tok = strpbrk(tmp_name, forbidden_name_chars);
82 if (tok) {
83 DBG("Session name %s contains a forbidden character", name);
84 /* Forbidden character has been found. */
85 ret = -1;
86 goto error;
87 }
88 ret = 0;
89
90error:
91 free(tmp_name);
92 return ret;
93}
94
5b74c7b1 95/*
050349bb 96 * Add a ltt_session structure to the global list.
5b74c7b1 97 *
050349bb 98 * The caller MUST acquire the session list lock before.
44e96653 99 * Returns the unique identifier for the session.
5b74c7b1 100 */
d022620a 101static uint64_t add_session_list(struct ltt_session *ls)
5b74c7b1 102{
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103 assert(ls);
104
5b74c7b1 105 cds_list_add(&ls->list, &ltt_session_list.head);
a24f7994 106 return ltt_session_list.next_uuid++;
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107}
108
109/*
050349bb 110 * Delete a ltt_session structure to the global list.
b5541356 111 *
050349bb 112 * The caller MUST acquire the session list lock before.
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113 */
114static void del_session_list(struct ltt_session *ls)
115{
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116 assert(ls);
117
5b74c7b1 118 cds_list_del(&ls->list);
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119}
120
b5541356 121/*
050349bb 122 * Return a pointer to the session list.
b5541356 123 */
54d01ffb 124struct ltt_session_list *session_get_list(void)
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125{
126 return &ltt_session_list;
127}
128
129/*
6c9cc2ab 130 * Acquire session list lock
b5541356 131 */
54d01ffb 132void session_lock_list(void)
b5541356 133{
6c9cc2ab 134 pthread_mutex_lock(&ltt_session_list.lock);
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135}
136
71e0a100
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137/*
138 * Try to acquire session list lock
139 */
140int session_trylock_list(void)
141{
142 return pthread_mutex_trylock(&ltt_session_list.lock);
143}
144
b5541356 145/*
6c9cc2ab 146 * Release session list lock
b5541356 147 */
54d01ffb 148void session_unlock_list(void)
b5541356 149{
6c9cc2ab 150 pthread_mutex_unlock(&ltt_session_list.lock);
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151}
152
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153/*
154 * Get the session's consumer destination type.
155 *
156 * The caller must hold the session lock.
157 */
158enum consumer_dst_type session_get_consumer_destination_type(
159 const struct ltt_session *session)
160{
161 /*
162 * The output information is duplicated in both of those session types.
163 * Hence, it doesn't matter from which it is retrieved. However, it is
164 * possible for only one of them to be set.
165 */
166 return session->kernel_session ?
167 session->kernel_session->consumer->type :
168 session->ust_session->consumer->type;
169}
170
171/*
172 * Get the session's consumer network hostname.
173 * The caller must ensure that the destination is of type "net".
174 *
175 * The caller must hold the session lock.
176 */
177const char *session_get_net_consumer_hostname(const struct ltt_session *session)
178{
179 const char *hostname = NULL;
180 const struct consumer_output *output;
181
182 output = session->kernel_session ?
183 session->kernel_session->consumer :
184 session->ust_session->consumer;
185
186 /*
187 * hostname is assumed to be the same for both control and data
188 * connections.
189 */
190 switch (output->dst.net.control.dtype) {
191 case LTTNG_DST_IPV4:
192 hostname = output->dst.net.control.dst.ipv4;
193 break;
194 case LTTNG_DST_IPV6:
195 hostname = output->dst.net.control.dst.ipv6;
196 break;
197 default:
198 abort();
199 }
200 return hostname;
201}
202
203/*
204 * Get the session's consumer network control and data ports.
205 * The caller must ensure that the destination is of type "net".
206 *
207 * The caller must hold the session lock.
208 */
209void session_get_net_consumer_ports(const struct ltt_session *session,
210 uint16_t *control_port, uint16_t *data_port)
211{
212 const struct consumer_output *output;
213
214 output = session->kernel_session ?
215 session->kernel_session->consumer :
216 session->ust_session->consumer;
217 *control_port = output->dst.net.control.port;
218 *data_port = output->dst.net.data.port;
219}
220
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221/*
222 * Allocate the ltt_sessions_ht_by_id HT.
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223 *
224 * The session list lock must be held.
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225 */
226int ltt_sessions_ht_alloc(void)
227{
228 int ret = 0;
229
230 DBG("Allocating ltt_sessions_ht_by_id");
231 ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
232 if (!ltt_sessions_ht_by_id) {
233 ret = -1;
234 ERR("Failed to allocate ltt_sessions_ht_by_id");
235 goto end;
236 }
237end:
238 return ret;
239}
240
241/*
242 * Destroy the ltt_sessions_ht_by_id HT.
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243 *
244 * The session list lock must be held.
23324029 245 */
accdc9bf 246static void ltt_sessions_ht_destroy(void)
23324029
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247{
248 if (!ltt_sessions_ht_by_id) {
249 return;
250 }
251 ht_cleanup_push(ltt_sessions_ht_by_id);
252 ltt_sessions_ht_by_id = NULL;
253}
254
255/*
256 * Add a ltt_session to the ltt_sessions_ht_by_id.
257 * If unallocated, the ltt_sessions_ht_by_id HT is allocated.
258 * The session list lock must be held.
259 */
260static void add_session_ht(struct ltt_session *ls)
261{
262 int ret;
263
264 assert(ls);
265
266 if (!ltt_sessions_ht_by_id) {
267 ret = ltt_sessions_ht_alloc();
268 if (ret) {
269 ERR("Error allocating the sessions HT");
270 goto end;
271 }
272 }
273 lttng_ht_node_init_u64(&ls->node, ls->id);
274 lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node);
275
276end:
277 return;
278}
279
280/*
281 * Test if ltt_sessions_ht_by_id is empty.
282 * Return 1 if empty, 0 if not empty.
283 * The session list lock must be held.
284 */
def88971 285static int ltt_sessions_ht_empty(void)
23324029
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286{
287 int ret;
288
289 if (!ltt_sessions_ht_by_id) {
290 ret = 1;
291 goto end;
292 }
293
294 ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1;
295end:
296 return ret;
297}
298
299/*
300 * Remove a ltt_session from the ltt_sessions_ht_by_id.
301 * If empty, the ltt_sessions_ht_by_id HT is freed.
302 * The session list lock must be held.
303 */
304static void del_session_ht(struct ltt_session *ls)
305{
306 struct lttng_ht_iter iter;
307 int ret;
308
309 assert(ls);
310 assert(ltt_sessions_ht_by_id);
311
312 iter.iter.node = &ls->node.node;
313 ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter);
314 assert(!ret);
315
316 if (ltt_sessions_ht_empty()) {
317 DBG("Empty ltt_sessions_ht_by_id, destroying it");
318 ltt_sessions_ht_destroy();
319 }
320}
321
b5541356 322/*
6c9cc2ab 323 * Acquire session lock
b5541356 324 */
54d01ffb 325void session_lock(struct ltt_session *session)
b5541356 326{
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327 assert(session);
328
6c9cc2ab
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329 pthread_mutex_lock(&session->lock);
330}
b5541356 331
6c9cc2ab
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332/*
333 * Release session lock
334 */
54d01ffb 335void session_unlock(struct ltt_session *session)
6c9cc2ab 336{
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337 assert(session);
338
6c9cc2ab 339 pthread_mutex_unlock(&session->lock);
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340}
341
5b74c7b1 342/*
74babd95 343 * Return a ltt_session structure ptr that matches name. If no session found,
23324029 344 * NULL is returned. This must be called with the session list lock held using
74babd95 345 * session_lock_list and session_unlock_list.
5b74c7b1 346 */
58a1a227 347struct ltt_session *session_find_by_name(const char *name)
5b74c7b1 348{
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349 struct ltt_session *iter;
350
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351 assert(name);
352
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353 DBG2("Trying to find session by name %s", name);
354
5b74c7b1 355 cds_list_for_each_entry(iter, &ltt_session_list.head, list) {
1b110e1b 356 if (strncmp(iter->name, name, NAME_MAX) == 0) {
74babd95 357 goto found;
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358 }
359 }
360
74babd95 361 iter = NULL;
5b74c7b1 362
74babd95 363found:
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364 return iter;
365}
366
23324029
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367/*
368 * Return an ltt_session that matches the id. If no session is found,
369 * NULL is returned. This must be called with rcu_read_lock and
370 * session list lock held (to guarantee the lifetime of the session).
371 */
372struct ltt_session *session_find_by_id(uint64_t id)
373{
374 struct lttng_ht_node_u64 *node;
375 struct lttng_ht_iter iter;
376 struct ltt_session *ls;
377
d68ec974
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378 if (!ltt_sessions_ht_by_id) {
379 goto end;
380 }
381
23324029
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382 lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
383 node = lttng_ht_iter_get_node_u64(&iter);
384 if (node == NULL) {
d68ec974 385 goto end;
23324029
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386 }
387 ls = caa_container_of(node, struct ltt_session, node);
388
389 DBG3("Session %" PRIu64 " found by id.", id);
390 return ls;
391
d68ec974 392end:
23324029
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393 DBG3("Session %" PRIu64 " NOT found by id", id);
394 return NULL;
395}
396
5b74c7b1 397/*
050349bb 398 * Delete session from the session list and free the memory.
5b74c7b1 399 *
050349bb 400 * Return -1 if no session is found. On success, return 1;
36b588ed 401 * Should *NOT* be called with RCU read-side lock held.
5b74c7b1 402 */
271933a4 403int session_destroy(struct ltt_session *session)
5b74c7b1 404{
271933a4 405 /* Safety check */
0525e9ae 406 assert(session);
271933a4 407
5c408ad8 408 DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
271933a4 409 del_session_list(session);
271933a4 410 pthread_mutex_destroy(&session->lock);
23324029 411 del_session_ht(session);
07424f16 412
6addfa37 413 consumer_output_put(session->consumer);
6dc3064a 414 snapshot_destroy(&session->snapshot);
271933a4 415 free(session);
5b74c7b1 416
f73fabfd 417 return LTTNG_OK;
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418}
419
420/*
050349bb 421 * Create a brand new session and add it to the session list.
5b74c7b1 422 */
dec56f6c 423int session_create(char *name, uid_t uid, gid_t gid)
5b74c7b1 424{
f3ed775e 425 int ret;
5b74c7b1 426 struct ltt_session *new_session;
e07ae692 427
5b74c7b1 428 /* Allocate session data structure */
ba7f0ae5 429 new_session = zmalloc(sizeof(struct ltt_session));
5b74c7b1 430 if (new_session == NULL) {
df0f840b 431 PERROR("zmalloc");
f73fabfd 432 ret = LTTNG_ERR_FATAL;
f3ed775e 433 goto error_malloc;
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434 }
435
f3ed775e 436 /* Define session name */
5b74c7b1 437 if (name != NULL) {
74babd95 438 if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) {
f73fabfd 439 ret = LTTNG_ERR_FATAL;
f3ed775e 440 goto error_asprintf;
5b74c7b1
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441 }
442 } else {
f3ed775e 443 ERR("No session name given");
f73fabfd 444 ret = LTTNG_ERR_FATAL;
f3ed775e
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445 goto error;
446 }
447
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448 ret = validate_name(name);
449 if (ret < 0) {
450 ret = LTTNG_ERR_SESSION_INVALID_CHAR;
451 goto error;
452 }
453
d3e2ba59 454 ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
73184835
DG
455 if (ret < 0) {
456 if (errno == ENAMETOOLONG) {
457 new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
458 } else {
459 ret = LTTNG_ERR_FATAL;
460 goto error;
461 }
d3e2ba59
JD
462 }
463
1d4b027a
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464 /* Init kernel session */
465 new_session->kernel_session = NULL;
f6a9efaa 466 new_session->ust_session = NULL;
1657e9bb 467
0177d773
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468 /* Init lock */
469 pthread_mutex_init(&new_session->lock, NULL);
5b74c7b1 470
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471 new_session->uid = uid;
472 new_session->gid = gid;
473
6dc3064a
DG
474 ret = snapshot_init(&new_session->snapshot);
475 if (ret < 0) {
476 ret = LTTNG_ERR_NOMEM;
477 goto error;
478 }
479
5c408ad8 480 new_session->rotate_pending = false;
4f23c583 481 new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
5c408ad8 482 new_session->rotate_pending_relay = false;
d88744a4 483 new_session->rotate_relay_pending_timer_enabled = false;
259c2674 484 new_session->rotate_timer = false;
5c408ad8 485
b5541356 486 /* Add new session to the session list */
54d01ffb 487 session_lock_list();
a991f516 488 new_session->id = add_session_list(new_session);
23324029
JD
489 /*
490 * Add the new session to the ltt_sessions_ht_by_id.
491 * No ownership is taken by the hash table; it is merely
492 * a wrapper around the session list used for faster access
493 * by session id.
494 */
495 add_session_ht(new_session);
54d01ffb 496 session_unlock_list();
b5541356 497
a4b92340
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498 /*
499 * Consumer is let to NULL since the create_session_uri command will set it
500 * up and, if valid, assign it to the session.
501 */
d022620a
DG
502 DBG("Tracing session %s created with ID %" PRIu64 " by UID %d GID %d",
503 name, new_session->id, new_session->uid, new_session->gid);
b082db07 504
f73fabfd 505 return LTTNG_OK;
5b74c7b1
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506
507error:
f3ed775e 508error_asprintf:
0e428499 509 free(new_session);
5b74c7b1 510
f3ed775e
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511error_malloc:
512 return ret;
5b74c7b1 513}
2f77fc4b
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514
515/*
516 * Check if the UID or GID match the session. Root user has access to all
517 * sessions.
518 */
519int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
520{
521 assert(session);
522
523 if (uid != session->uid && gid != session->gid && uid != 0) {
524 return 0;
525 } else {
526 return 1;
527 }
528}
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