| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 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. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 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. |
| 16 | */ |
| 17 | |
| 18 | #define _LGPL_SOURCE |
| 19 | #include <limits.h> |
| 20 | #include <inttypes.h> |
| 21 | #include <stdio.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | #include <sys/stat.h> |
| 25 | #include <urcu.h> |
| 26 | #include <dirent.h> |
| 27 | #include <sys/types.h> |
| 28 | #include <pthread.h> |
| 29 | |
| 30 | #include <common/common.h> |
| 31 | #include <common/sessiond-comm/sessiond-comm.h> |
| 32 | #include <lttng/location-internal.h> |
| 33 | #include "lttng-sessiond.h" |
| 34 | #include "kernel.h" |
| 35 | |
| 36 | #include "session.h" |
| 37 | #include "utils.h" |
| 38 | #include "trace-ust.h" |
| 39 | #include "timer.h" |
| 40 | |
| 41 | /* |
| 42 | * NOTES: |
| 43 | * |
| 44 | * No ltt_session.lock is taken here because those data structure are widely |
| 45 | * spread across the lttng-tools code base so before caling functions below |
| 46 | * that can read/write a session, the caller MUST acquire the session lock |
| 47 | * using session_lock() and session_unlock(). |
| 48 | */ |
| 49 | |
| 50 | /* |
| 51 | * Init tracing session list. |
| 52 | * |
| 53 | * Please see session.h for more explanation and correct usage of the list. |
| 54 | */ |
| 55 | static struct ltt_session_list ltt_session_list = { |
| 56 | .head = CDS_LIST_HEAD_INIT(ltt_session_list.head), |
| 57 | .lock = PTHREAD_MUTEX_INITIALIZER, |
| 58 | .removal_cond = PTHREAD_COND_INITIALIZER, |
| 59 | .next_uuid = 0, |
| 60 | }; |
| 61 | |
| 62 | /* These characters are forbidden in a session name. Used by validate_name. */ |
| 63 | static const char *forbidden_name_chars = "/"; |
| 64 | |
| 65 | /* Global hash table to keep the sessions, indexed by id. */ |
| 66 | static struct lttng_ht *ltt_sessions_ht_by_id = NULL; |
| 67 | |
| 68 | /* |
| 69 | * Validate the session name for forbidden characters. |
| 70 | * |
| 71 | * Return 0 on success else -1 meaning a forbidden char. has been found. |
| 72 | */ |
| 73 | static int validate_name(const char *name) |
| 74 | { |
| 75 | int ret; |
| 76 | char *tok, *tmp_name; |
| 77 | |
| 78 | assert(name); |
| 79 | |
| 80 | tmp_name = strdup(name); |
| 81 | if (!tmp_name) { |
| 82 | /* ENOMEM here. */ |
| 83 | ret = -1; |
| 84 | goto error; |
| 85 | } |
| 86 | |
| 87 | tok = strpbrk(tmp_name, forbidden_name_chars); |
| 88 | if (tok) { |
| 89 | DBG("Session name %s contains a forbidden character", name); |
| 90 | /* Forbidden character has been found. */ |
| 91 | ret = -1; |
| 92 | goto error; |
| 93 | } |
| 94 | ret = 0; |
| 95 | |
| 96 | error: |
| 97 | free(tmp_name); |
| 98 | return ret; |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * Add a ltt_session structure to the global list. |
| 103 | * |
| 104 | * The caller MUST acquire the session list lock before. |
| 105 | * Returns the unique identifier for the session. |
| 106 | */ |
| 107 | static uint64_t add_session_list(struct ltt_session *ls) |
| 108 | { |
| 109 | assert(ls); |
| 110 | |
| 111 | cds_list_add(&ls->list, <t_session_list.head); |
| 112 | return ltt_session_list.next_uuid++; |
| 113 | } |
| 114 | |
| 115 | /* |
| 116 | * Delete a ltt_session structure to the global list. |
| 117 | * |
| 118 | * The caller MUST acquire the session list lock before. |
| 119 | */ |
| 120 | static void del_session_list(struct ltt_session *ls) |
| 121 | { |
| 122 | assert(ls); |
| 123 | |
| 124 | cds_list_del(&ls->list); |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Return a pointer to the session list. |
| 129 | */ |
| 130 | struct ltt_session_list *session_get_list(void) |
| 131 | { |
| 132 | return <t_session_list; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * Returns once the session list is empty. |
| 137 | */ |
| 138 | void session_list_wait_empty(void) |
| 139 | { |
| 140 | pthread_mutex_lock(<t_session_list.lock); |
| 141 | while (!cds_list_empty(<t_session_list.head)) { |
| 142 | pthread_cond_wait(<t_session_list.removal_cond, |
| 143 | <t_session_list.lock); |
| 144 | } |
| 145 | pthread_mutex_unlock(<t_session_list.lock); |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * Acquire session list lock |
| 150 | */ |
| 151 | void session_lock_list(void) |
| 152 | { |
| 153 | pthread_mutex_lock(<t_session_list.lock); |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * Try to acquire session list lock |
| 158 | */ |
| 159 | int session_trylock_list(void) |
| 160 | { |
| 161 | return pthread_mutex_trylock(<t_session_list.lock); |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * Release session list lock |
| 166 | */ |
| 167 | void session_unlock_list(void) |
| 168 | { |
| 169 | pthread_mutex_unlock(<t_session_list.lock); |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Get the session's consumer destination type. |
| 174 | * |
| 175 | * The caller must hold the session lock. |
| 176 | */ |
| 177 | enum consumer_dst_type session_get_consumer_destination_type( |
| 178 | const struct ltt_session *session) |
| 179 | { |
| 180 | /* |
| 181 | * The output information is duplicated in both of those session types. |
| 182 | * Hence, it doesn't matter from which it is retrieved. However, it is |
| 183 | * possible for only one of them to be set. |
| 184 | */ |
| 185 | return session->kernel_session ? |
| 186 | session->kernel_session->consumer->type : |
| 187 | session->ust_session->consumer->type; |
| 188 | } |
| 189 | |
| 190 | /* |
| 191 | * Get the session's consumer network hostname. |
| 192 | * The caller must ensure that the destination is of type "net". |
| 193 | * |
| 194 | * The caller must hold the session lock. |
| 195 | */ |
| 196 | const char *session_get_net_consumer_hostname(const struct ltt_session *session) |
| 197 | { |
| 198 | const char *hostname = NULL; |
| 199 | const struct consumer_output *output; |
| 200 | |
| 201 | output = session->kernel_session ? |
| 202 | session->kernel_session->consumer : |
| 203 | session->ust_session->consumer; |
| 204 | |
| 205 | /* |
| 206 | * hostname is assumed to be the same for both control and data |
| 207 | * connections. |
| 208 | */ |
| 209 | switch (output->dst.net.control.dtype) { |
| 210 | case LTTNG_DST_IPV4: |
| 211 | hostname = output->dst.net.control.dst.ipv4; |
| 212 | break; |
| 213 | case LTTNG_DST_IPV6: |
| 214 | hostname = output->dst.net.control.dst.ipv6; |
| 215 | break; |
| 216 | default: |
| 217 | abort(); |
| 218 | } |
| 219 | return hostname; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Get the session's consumer network control and data ports. |
| 224 | * The caller must ensure that the destination is of type "net". |
| 225 | * |
| 226 | * The caller must hold the session lock. |
| 227 | */ |
| 228 | void session_get_net_consumer_ports(const struct ltt_session *session, |
| 229 | uint16_t *control_port, uint16_t *data_port) |
| 230 | { |
| 231 | const struct consumer_output *output; |
| 232 | |
| 233 | output = session->kernel_session ? |
| 234 | session->kernel_session->consumer : |
| 235 | session->ust_session->consumer; |
| 236 | *control_port = output->dst.net.control.port; |
| 237 | *data_port = output->dst.net.data.port; |
| 238 | } |
| 239 | |
| 240 | /* |
| 241 | * Get the location of the latest trace archive produced by a rotation. |
| 242 | * |
| 243 | * The caller must hold the session lock. |
| 244 | */ |
| 245 | struct lttng_trace_archive_location *session_get_trace_archive_location( |
| 246 | struct ltt_session *session) |
| 247 | { |
| 248 | struct lttng_trace_archive_location *location = NULL; |
| 249 | |
| 250 | if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) { |
| 251 | goto end; |
| 252 | } |
| 253 | |
| 254 | switch (session_get_consumer_destination_type(session)) { |
| 255 | case CONSUMER_DST_LOCAL: |
| 256 | location = lttng_trace_archive_location_local_create( |
| 257 | session->rotation_chunk.current_rotate_path); |
| 258 | break; |
| 259 | case CONSUMER_DST_NET: |
| 260 | { |
| 261 | const char *hostname; |
| 262 | uint16_t control_port, data_port; |
| 263 | |
| 264 | hostname = session_get_net_consumer_hostname(session); |
| 265 | session_get_net_consumer_ports(session, |
| 266 | &control_port, |
| 267 | &data_port); |
| 268 | location = lttng_trace_archive_location_relay_create( |
| 269 | hostname, |
| 270 | LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP, |
| 271 | control_port, data_port, |
| 272 | session->rotation_chunk.current_rotate_path); |
| 273 | break; |
| 274 | } |
| 275 | default: |
| 276 | abort(); |
| 277 | } |
| 278 | end: |
| 279 | return location; |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * Allocate the ltt_sessions_ht_by_id HT. |
| 284 | * |
| 285 | * The session list lock must be held. |
| 286 | */ |
| 287 | int ltt_sessions_ht_alloc(void) |
| 288 | { |
| 289 | int ret = 0; |
| 290 | |
| 291 | DBG("Allocating ltt_sessions_ht_by_id"); |
| 292 | ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64); |
| 293 | if (!ltt_sessions_ht_by_id) { |
| 294 | ret = -1; |
| 295 | ERR("Failed to allocate ltt_sessions_ht_by_id"); |
| 296 | goto end; |
| 297 | } |
| 298 | end: |
| 299 | return ret; |
| 300 | } |
| 301 | |
| 302 | /* |
| 303 | * Destroy the ltt_sessions_ht_by_id HT. |
| 304 | * |
| 305 | * The session list lock must be held. |
| 306 | */ |
| 307 | static void ltt_sessions_ht_destroy(void) |
| 308 | { |
| 309 | if (!ltt_sessions_ht_by_id) { |
| 310 | return; |
| 311 | } |
| 312 | ht_cleanup_push(ltt_sessions_ht_by_id); |
| 313 | ltt_sessions_ht_by_id = NULL; |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Add a ltt_session to the ltt_sessions_ht_by_id. |
| 318 | * If unallocated, the ltt_sessions_ht_by_id HT is allocated. |
| 319 | * The session list lock must be held. |
| 320 | */ |
| 321 | static void add_session_ht(struct ltt_session *ls) |
| 322 | { |
| 323 | int ret; |
| 324 | |
| 325 | assert(ls); |
| 326 | |
| 327 | if (!ltt_sessions_ht_by_id) { |
| 328 | ret = ltt_sessions_ht_alloc(); |
| 329 | if (ret) { |
| 330 | ERR("Error allocating the sessions HT"); |
| 331 | goto end; |
| 332 | } |
| 333 | } |
| 334 | lttng_ht_node_init_u64(&ls->node, ls->id); |
| 335 | lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node); |
| 336 | |
| 337 | end: |
| 338 | return; |
| 339 | } |
| 340 | |
| 341 | /* |
| 342 | * Test if ltt_sessions_ht_by_id is empty. |
| 343 | * Return 1 if empty, 0 if not empty. |
| 344 | * The session list lock must be held. |
| 345 | */ |
| 346 | static int ltt_sessions_ht_empty(void) |
| 347 | { |
| 348 | int ret; |
| 349 | |
| 350 | if (!ltt_sessions_ht_by_id) { |
| 351 | ret = 1; |
| 352 | goto end; |
| 353 | } |
| 354 | |
| 355 | ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1; |
| 356 | end: |
| 357 | return ret; |
| 358 | } |
| 359 | |
| 360 | /* |
| 361 | * Remove a ltt_session from the ltt_sessions_ht_by_id. |
| 362 | * If empty, the ltt_sessions_ht_by_id HT is freed. |
| 363 | * The session list lock must be held. |
| 364 | */ |
| 365 | static void del_session_ht(struct ltt_session *ls) |
| 366 | { |
| 367 | struct lttng_ht_iter iter; |
| 368 | int ret; |
| 369 | |
| 370 | assert(ls); |
| 371 | assert(ltt_sessions_ht_by_id); |
| 372 | |
| 373 | iter.iter.node = &ls->node.node; |
| 374 | ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter); |
| 375 | assert(!ret); |
| 376 | |
| 377 | if (ltt_sessions_ht_empty()) { |
| 378 | DBG("Empty ltt_sessions_ht_by_id, destroying it"); |
| 379 | ltt_sessions_ht_destroy(); |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * Acquire session lock |
| 385 | */ |
| 386 | void session_lock(struct ltt_session *session) |
| 387 | { |
| 388 | assert(session); |
| 389 | |
| 390 | pthread_mutex_lock(&session->lock); |
| 391 | } |
| 392 | |
| 393 | /* |
| 394 | * Release session lock |
| 395 | */ |
| 396 | void session_unlock(struct ltt_session *session) |
| 397 | { |
| 398 | assert(session); |
| 399 | |
| 400 | pthread_mutex_unlock(&session->lock); |
| 401 | } |
| 402 | |
| 403 | static |
| 404 | void session_release(struct urcu_ref *ref) |
| 405 | { |
| 406 | int ret; |
| 407 | struct ltt_ust_session *usess; |
| 408 | struct ltt_kernel_session *ksess; |
| 409 | struct ltt_session *session = container_of(ref, typeof(*session), ref); |
| 410 | |
| 411 | usess = session->ust_session; |
| 412 | ksess = session->kernel_session; |
| 413 | |
| 414 | /* Clean kernel session teardown */ |
| 415 | kernel_destroy_session(ksess); |
| 416 | |
| 417 | /* UST session teardown */ |
| 418 | if (usess) { |
| 419 | /* Close any relayd session */ |
| 420 | consumer_output_send_destroy_relayd(usess->consumer); |
| 421 | |
| 422 | /* Destroy every UST application related to this session. */ |
| 423 | ret = ust_app_destroy_trace_all(usess); |
| 424 | if (ret) { |
| 425 | ERR("Error in ust_app_destroy_trace_all"); |
| 426 | } |
| 427 | |
| 428 | /* Clean up the rest. */ |
| 429 | trace_ust_destroy_session(usess); |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Must notify the kernel thread here to update it's poll set in order to |
| 434 | * remove the channel(s)' fd just destroyed. |
| 435 | */ |
| 436 | ret = notify_thread_pipe(kernel_poll_pipe[1]); |
| 437 | if (ret < 0) { |
| 438 | PERROR("write kernel poll pipe"); |
| 439 | } |
| 440 | |
| 441 | DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id); |
| 442 | pthread_mutex_destroy(&session->lock); |
| 443 | |
| 444 | consumer_output_put(session->consumer); |
| 445 | snapshot_destroy(&session->snapshot); |
| 446 | |
| 447 | if (session->published) { |
| 448 | ASSERT_LOCKED(ltt_session_list.lock); |
| 449 | del_session_list(session); |
| 450 | del_session_ht(session); |
| 451 | pthread_cond_broadcast(<t_session_list.removal_cond); |
| 452 | } |
| 453 | free(session); |
| 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Acquire a reference to a session. |
| 458 | * This function may fail (return false); its return value must be checked. |
| 459 | */ |
| 460 | bool session_get(struct ltt_session *session) |
| 461 | { |
| 462 | return urcu_ref_get_unless_zero(&session->ref); |
| 463 | } |
| 464 | |
| 465 | /* |
| 466 | * Release a reference to a session. |
| 467 | */ |
| 468 | void session_put(struct ltt_session *session) |
| 469 | { |
| 470 | if (!session) { |
| 471 | return; |
| 472 | } |
| 473 | /* |
| 474 | * The session list lock must be held as any session_put() |
| 475 | * may cause the removal of the session from the session_list. |
| 476 | */ |
| 477 | ASSERT_LOCKED(ltt_session_list.lock); |
| 478 | assert(session->ref.refcount); |
| 479 | urcu_ref_put(&session->ref, session_release); |
| 480 | } |
| 481 | |
| 482 | /* |
| 483 | * Destroy a session. |
| 484 | * |
| 485 | * This method does not immediately release/free the session as other |
| 486 | * components may still hold a reference to the session. However, |
| 487 | * the session should no longer be presented to the user. |
| 488 | * |
| 489 | * Releases the session list's reference to the session |
| 490 | * and marks it as destroyed. Iterations on the session list should be |
| 491 | * mindful of the "destroyed" flag. |
| 492 | */ |
| 493 | void session_destroy(struct ltt_session *session) |
| 494 | { |
| 495 | assert(!session->destroyed); |
| 496 | session->destroyed = true; |
| 497 | session_put(session); |
| 498 | } |
| 499 | |
| 500 | /* |
| 501 | * Return a ltt_session structure ptr that matches name. If no session found, |
| 502 | * NULL is returned. This must be called with the session list lock held using |
| 503 | * session_lock_list and session_unlock_list. |
| 504 | * A reference to the session is implicitly acquired by this function. |
| 505 | */ |
| 506 | struct ltt_session *session_find_by_name(const char *name) |
| 507 | { |
| 508 | struct ltt_session *iter; |
| 509 | |
| 510 | assert(name); |
| 511 | ASSERT_LOCKED(ltt_session_list.lock); |
| 512 | |
| 513 | DBG2("Trying to find session by name %s", name); |
| 514 | |
| 515 | cds_list_for_each_entry(iter, <t_session_list.head, list) { |
| 516 | if (!strncmp(iter->name, name, NAME_MAX) && |
| 517 | !iter->destroyed) { |
| 518 | goto found; |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | return NULL; |
| 523 | found: |
| 524 | return session_get(iter) ? iter : NULL; |
| 525 | } |
| 526 | |
| 527 | /* |
| 528 | * Return an ltt_session that matches the id. If no session is found, |
| 529 | * NULL is returned. This must be called with rcu_read_lock and |
| 530 | * session list lock held (to guarantee the lifetime of the session). |
| 531 | */ |
| 532 | struct ltt_session *session_find_by_id(uint64_t id) |
| 533 | { |
| 534 | struct lttng_ht_node_u64 *node; |
| 535 | struct lttng_ht_iter iter; |
| 536 | struct ltt_session *ls; |
| 537 | |
| 538 | ASSERT_LOCKED(ltt_session_list.lock); |
| 539 | |
| 540 | if (!ltt_sessions_ht_by_id) { |
| 541 | goto end; |
| 542 | } |
| 543 | |
| 544 | lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter); |
| 545 | node = lttng_ht_iter_get_node_u64(&iter); |
| 546 | if (node == NULL) { |
| 547 | goto end; |
| 548 | } |
| 549 | ls = caa_container_of(node, struct ltt_session, node); |
| 550 | |
| 551 | DBG3("Session %" PRIu64 " found by id.", id); |
| 552 | return session_get(ls) ? ls : NULL; |
| 553 | |
| 554 | end: |
| 555 | DBG3("Session %" PRIu64 " NOT found by id", id); |
| 556 | return NULL; |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | * Create a new session and add it to the session list. |
| 561 | * Session list lock must be held by the caller. |
| 562 | */ |
| 563 | enum lttng_error_code session_create(const char *name, uid_t uid, gid_t gid, |
| 564 | struct ltt_session **out_session) |
| 565 | { |
| 566 | int ret; |
| 567 | enum lttng_error_code ret_code; |
| 568 | struct ltt_session *new_session = NULL; |
| 569 | |
| 570 | ASSERT_LOCKED(ltt_session_list.lock); |
| 571 | if (name) { |
| 572 | struct ltt_session *clashing_session; |
| 573 | |
| 574 | clashing_session = session_find_by_name(name); |
| 575 | if (clashing_session) { |
| 576 | session_put(clashing_session); |
| 577 | ret_code = LTTNG_ERR_EXIST_SESS; |
| 578 | goto error; |
| 579 | } |
| 580 | } |
| 581 | new_session = zmalloc(sizeof(struct ltt_session)); |
| 582 | if (!new_session) { |
| 583 | PERROR("Failed to allocate an ltt_session structure"); |
| 584 | ret_code = LTTNG_ERR_NOMEM; |
| 585 | goto error; |
| 586 | } |
| 587 | |
| 588 | urcu_ref_init(&new_session->ref); |
| 589 | pthread_mutex_init(&new_session->lock, NULL); |
| 590 | |
| 591 | new_session->creation_time = time(NULL); |
| 592 | if (new_session->creation_time == (time_t) -1) { |
| 593 | PERROR("Failed to sample session creation time"); |
| 594 | ret_code = LTTNG_ERR_SESSION_FAIL; |
| 595 | goto error; |
| 596 | } |
| 597 | |
| 598 | /* Create default consumer output. */ |
| 599 | new_session->consumer = consumer_create_output(CONSUMER_DST_LOCAL); |
| 600 | if (new_session->consumer == NULL) { |
| 601 | ret_code = LTTNG_ERR_NOMEM; |
| 602 | goto error; |
| 603 | } |
| 604 | |
| 605 | if (name) { |
| 606 | ret = lttng_strncpy(new_session->name, name, sizeof(new_session->name)); |
| 607 | if (ret) { |
| 608 | ret_code = LTTNG_ERR_SESSION_INVALID_CHAR; |
| 609 | goto error; |
| 610 | } |
| 611 | ret = validate_name(name); |
| 612 | if (ret < 0) { |
| 613 | ret_code = LTTNG_ERR_SESSION_INVALID_CHAR; |
| 614 | goto error; |
| 615 | } |
| 616 | } else { |
| 617 | int i = 0; |
| 618 | bool found_name = false; |
| 619 | char datetime[16]; |
| 620 | struct tm *timeinfo; |
| 621 | |
| 622 | timeinfo = localtime(&new_session->creation_time); |
| 623 | if (!timeinfo) { |
| 624 | ret_code = LTTNG_ERR_SESSION_FAIL; |
| 625 | goto error; |
| 626 | } |
| 627 | strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo); |
| 628 | for (i = 0; i < INT_MAX; i++) { |
| 629 | struct ltt_session *clashing_session; |
| 630 | |
| 631 | if (i == 0) { |
| 632 | ret = snprintf(new_session->name, |
| 633 | sizeof(new_session->name), |
| 634 | "%s-%s", |
| 635 | DEFAULT_SESSION_NAME, |
| 636 | datetime); |
| 637 | } else { |
| 638 | ret = snprintf(new_session->name, |
| 639 | sizeof(new_session->name), |
| 640 | "%s%d-%s", |
| 641 | DEFAULT_SESSION_NAME, i, |
| 642 | datetime); |
| 643 | } |
| 644 | if (ret == -1 || ret >= sizeof(new_session->name)) { |
| 645 | /* |
| 646 | * Null-terminate in case the name is used |
| 647 | * in logging statements. |
| 648 | */ |
| 649 | new_session->name[sizeof(new_session->name) - 1] = '\0'; |
| 650 | ret_code = LTTNG_ERR_SESSION_FAIL; |
| 651 | goto error; |
| 652 | } |
| 653 | |
| 654 | clashing_session = |
| 655 | session_find_by_name(new_session->name); |
| 656 | session_put(clashing_session); |
| 657 | if (!clashing_session) { |
| 658 | found_name = true; |
| 659 | break; |
| 660 | } |
| 661 | } |
| 662 | if (found_name) { |
| 663 | DBG("Generated session name \"%s\"", new_session->name); |
| 664 | new_session->has_auto_generated_name = true; |
| 665 | } else { |
| 666 | ERR("Failed to auto-generate a session name"); |
| 667 | ret_code = LTTNG_ERR_SESSION_FAIL; |
| 668 | goto error; |
| 669 | } |
| 670 | } |
| 671 | |
| 672 | ret = gethostname(new_session->hostname, sizeof(new_session->hostname)); |
| 673 | if (ret < 0) { |
| 674 | if (errno == ENAMETOOLONG) { |
| 675 | new_session->hostname[sizeof(new_session->hostname) - 1] = '\0'; |
| 676 | ERR("Hostname exceeds the maximal permitted length and has been truncated to %s", |
| 677 | new_session->hostname); |
| 678 | } else { |
| 679 | ret_code = LTTNG_ERR_SESSION_FAIL; |
| 680 | goto error; |
| 681 | } |
| 682 | } |
| 683 | |
| 684 | new_session->uid = uid; |
| 685 | new_session->gid = gid; |
| 686 | |
| 687 | ret = snapshot_init(&new_session->snapshot); |
| 688 | if (ret < 0) { |
| 689 | ret_code = LTTNG_ERR_NOMEM; |
| 690 | goto error; |
| 691 | } |
| 692 | |
| 693 | new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION; |
| 694 | |
| 695 | /* Add new session to the session list. */ |
| 696 | new_session->id = add_session_list(new_session); |
| 697 | |
| 698 | /* |
| 699 | * Add the new session to the ltt_sessions_ht_by_id. |
| 700 | * No ownership is taken by the hash table; it is merely |
| 701 | * a wrapper around the session list used for faster access |
| 702 | * by session id. |
| 703 | */ |
| 704 | add_session_ht(new_session); |
| 705 | new_session->published = true; |
| 706 | |
| 707 | /* |
| 708 | * Consumer is left to NULL since the create_session_uri command will |
| 709 | * set it up and, if valid, assign it to the session. |
| 710 | */ |
| 711 | DBG("Tracing session %s created with ID %" PRIu64 " by uid = %d, gid = %d", |
| 712 | new_session->name, new_session->id, new_session->uid, |
| 713 | new_session->gid); |
| 714 | ret_code = LTTNG_OK; |
| 715 | end: |
| 716 | if (new_session) { |
| 717 | (void) session_get(new_session); |
| 718 | *out_session = new_session; |
| 719 | } |
| 720 | return ret_code; |
| 721 | error: |
| 722 | session_put(new_session); |
| 723 | new_session = NULL; |
| 724 | goto end; |
| 725 | } |
| 726 | |
| 727 | /* |
| 728 | * Check if the UID or GID match the session. Root user has access to all |
| 729 | * sessions. |
| 730 | */ |
| 731 | int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid) |
| 732 | { |
| 733 | assert(session); |
| 734 | |
| 735 | if (uid != session->uid && gid != session->gid && uid != 0) { |
| 736 | return 0; |
| 737 | } else { |
| 738 | return 1; |
| 739 | } |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Set a session's rotation state and reset all associated state. |
| 744 | * |
| 745 | * This function resets the rotation state (check timers, pending |
| 746 | * flags, etc.) and sets the result of the last rotation. The result |
| 747 | * can be queries by a liblttng-ctl client. |
| 748 | * |
| 749 | * Be careful of the result passed to this function. For instance, |
| 750 | * on failure to launch a rotation, a client will expect the rotation |
| 751 | * state to be set to "NO_ROTATION". If an error occured while the |
| 752 | * rotation was "ONGOING", result should be set to "ERROR", which will |
| 753 | * allow a client to report it. |
| 754 | * |
| 755 | * Must be called with the session and session_list locks held. |
| 756 | */ |
| 757 | int session_reset_rotation_state(struct ltt_session *session, |
| 758 | enum lttng_rotation_state result) |
| 759 | { |
| 760 | int ret = 0; |
| 761 | |
| 762 | ASSERT_LOCKED(ltt_session_list.lock); |
| 763 | ASSERT_LOCKED(session->lock); |
| 764 | |
| 765 | session->rotation_pending_local = false; |
| 766 | session->rotation_pending_relay = false; |
| 767 | session->rotated_after_last_stop = false; |
| 768 | session->rotation_state = result; |
| 769 | if (session->rotation_pending_check_timer_enabled) { |
| 770 | ret = timer_session_rotation_pending_check_stop(session); |
| 771 | } |
| 772 | return ret; |
| 773 | } |