src/bin/lttng-relayd/session.cpp

   1 /*
   2  * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   4  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-only
   7  *
   8  */
   9
  10 #define _LGPL_SOURCE
  11 #include "ctf-trace.hpp"
  12 #include "lttng-relayd.hpp"
  13 #include "session.hpp"
  14 #include "sessiond-trace-chunks.hpp"
  15 #include "stream.hpp"
  16 #include "utils.hpp"
  17
  18 #include <common/common.hpp>
  19 #include <common/compat/path.hpp>
  20 #include <common/defaults.hpp>
  21 #include <common/fd-tracker/utils.hpp>
  22 #include <common/time.hpp>
  23 #include <common/utils.hpp>
  24 #include <common/uuid.hpp>
  25
  26 #include <sys/stat.h>
  27 #include <urcu/rculist.h>
  28
  29 /* Global session id used in the session creation. */
  30 static uint64_t last_relay_session_id;
  31 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
  32
  33 static int init_session_output_path_group_by_host(struct relay_session *session)
  34 {
  35         /*
  36          * session_directory:
  37          *
  38          * if base_path is \0'
  39          *   hostname/session_name
  40          * else
  41          *   hostname/base_path
  42          */
  43         char *session_directory = nullptr;
  44         int ret = 0;
  45
  46         if (session->output_path[0] != '\0') {
  47                 goto end;
  48         }
  49         /*
  50          * If base path is set, it overrides the session name for the
  51          * session relative base path. No timestamp is appended if the
  52          * base path is overridden.
  53          *
  54          * If the session name already contains the creation time (e.g.
  55          * auto-<timestamp>, don't append yet another timestamp after
  56          * the session name in the generated path.
  57          *
  58          * Otherwise, generate the path with session_name-<timestamp>.
  59          */
  60         if (session->base_path[0] != '\0') {
  61                 ret = asprintf(&session_directory, "%s/%s", session->hostname, session->base_path);
  62         } else if (session->session_name_contains_creation_time) {
  63                 ret = asprintf(
  64                         &session_directory, "%s/%s", session->hostname, session->session_name);
  65         } else {
  66                 char session_creation_datetime[DATETIME_STR_LEN];
  67
  68                 ret = time_to_datetime_str(LTTNG_OPTIONAL_GET(session->creation_time),
  69                                            session_creation_datetime,
  70                                            sizeof(session_creation_datetime));
  71                 if (ret) {
  72                         ERR("Failed to format session creation timestamp while initializing session output directory handle");
  73                         ret = -1;
  74                         goto end;
  75                 }
  76
  77                 ret = asprintf(&session_directory,
  78                                "%s/%s-%s",
  79                                session->hostname,
  80                                session->session_name,
  81                                session_creation_datetime);
  82         }
  83         if (ret < 0) {
  84                 PERROR("Failed to format session directory name");
  85                 goto end;
  86         }
  87
  88         if (strlen(session_directory) >= LTTNG_PATH_MAX) {
  89                 ERR("Session output directory exceeds maximal length");
  90                 ret = -1;
  91                 goto end;
  92         }
  93         strcpy(session->output_path, session_directory);
  94         ret = 0;
  95
  96 end:
  97         free(session_directory);
  98         return ret;
  99 }
 100
 101 static int init_session_output_path_group_by_session(struct relay_session *session)
 102 {
 103         /*
 104          * session_directory:
 105          *
 106          *   session_name/hostname-creation_time/base_path
 107          *
 108          * For session name including the datetime, use it as the complete name
 109          * since. Do not perform modification on it since the datetime is an
 110          * integral part of the name and how a user identify a session.
 111          */
 112         int ret = 0;
 113         char *session_directory = nullptr;
 114         char creation_datetime[DATETIME_STR_LEN];
 115
 116         if (session->output_path[0] != '\0') {
 117                 /* output_path as been generated already */
 118                 goto end;
 119         }
 120
 121         ret = time_to_datetime_str(LTTNG_OPTIONAL_GET(session->creation_time),
 122                                    creation_datetime,
 123                                    sizeof(creation_datetime));
 124         if (ret) {
 125                 ERR("Failed to format session creation timestamp while initializing session output directory handle");
 126                 ret = -1;
 127                 goto end;
 128         }
 129
 130         ret = asprintf(&session_directory,
 131                        "%s/%s-%s%s%s",
 132                        session->session_name,
 133                        session->hostname,
 134                        creation_datetime,
 135                        session->base_path[0] != '\0' ? "/" : "",
 136                        session->base_path);
 137         if (ret < 0) {
 138                 PERROR("Failed to format session directory name");
 139                 goto end;
 140         }
 141
 142         if (strlen(session_directory) >= LTTNG_PATH_MAX) {
 143                 ERR("Session output directory exceeds maximal length");
 144                 ret = -1;
 145                 goto end;
 146         }
 147
 148         strcpy(session->output_path, session_directory);
 149         ret = 0;
 150
 151 end:
 152         free(session_directory);
 153         return ret;
 154 }
 155
 156 static int init_session_output_path(struct relay_session *session)
 157 {
 158         int ret;
 159
 160         switch (opt_group_output_by) {
 161         case RELAYD_GROUP_OUTPUT_BY_HOST:
 162                 ret = init_session_output_path_group_by_host(session);
 163                 break;
 164         case RELAYD_GROUP_OUTPUT_BY_SESSION:
 165                 ret = init_session_output_path_group_by_session(session);
 166                 break;
 167         case RELAYD_GROUP_OUTPUT_BY_UNKNOWN:
 168         default:
 169                 abort();
 170                 break;
 171         }
 172
 173         return ret;
 174 }
 175
 176 static struct lttng_directory_handle *
 177 session_create_output_directory_handle(struct relay_session *session)
 178 {
 179         int ret;
 180         /*
 181          * relayd_output_path/session_directory
 182          * e.g. /home/user/lttng-traces/hostname/session_name
 183          */
 184         char *full_session_path = nullptr;
 185         struct lttng_directory_handle *handle = nullptr;
 186
 187         pthread_mutex_lock(&session->lock);
 188         full_session_path = create_output_path(session->output_path);
 189         if (!full_session_path) {
 190                 goto end;
 191         }
 192
 193         ret = utils_mkdir_recursive(full_session_path, S_IRWXU | S_IRWXG, -1, -1);
 194         if (ret) {
 195                 ERR("Failed to create session output path \"%s\"", full_session_path);
 196                 goto end;
 197         }
 198
 199         handle = fd_tracker_create_directory_handle(the_fd_tracker, full_session_path);
 200 end:
 201         pthread_mutex_unlock(&session->lock);
 202         free(full_session_path);
 203         return handle;
 204 }
 205
 206 static int session_set_anonymous_chunk(struct relay_session *session)
 207 {
 208         int ret = 0;
 209         struct lttng_trace_chunk *chunk = nullptr;
 210         enum lttng_trace_chunk_status status;
 211         struct lttng_directory_handle *output_directory;
 212
 213         output_directory = session_create_output_directory_handle(session);
 214         if (!output_directory) {
 215                 goto end;
 216         }
 217
 218         chunk = lttng_trace_chunk_create_anonymous();
 219         if (!chunk) {
 220                 goto end;
 221         }
 222
 223         lttng_trace_chunk_set_fd_tracker(chunk, the_fd_tracker);
 224         status = lttng_trace_chunk_set_credentials_current_user(chunk);
 225         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 226                 ret = -1;
 227                 goto end;
 228         }
 229
 230         status = lttng_trace_chunk_set_as_owner(chunk, output_directory);
 231         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 232                 ret = -1;
 233                 goto end;
 234         }
 235
 236         session->current_trace_chunk = chunk;
 237         chunk = nullptr;
 238 end:
 239         lttng_trace_chunk_put(chunk);
 240         lttng_directory_handle_put(output_directory);
 241         return ret;
 242 }
 243
 244 /*
 245  * Check if a name is safe to use in a path.
 246  *
 247  * A name that is deemed "path-safe":
 248  *   - Does not contains a path separator (/ or \, platform dependant),
 249  *   - Does not start with a '.' (hidden file/folder),
 250  *   - Is not empty.
 251  */
 252 static bool is_name_path_safe(const char *name)
 253 {
 254         const size_t name_len = strlen(name);
 255
 256         /* Not empty. */
 257         if (name_len == 0) {
 258                 WARN("An empty name is not allowed to be used in a path");
 259                 return false;
 260         }
 261         /* Does not start with '.'. */
 262         if (name[0] == '.') {
 263                 WARN("Name \"%s\" is not allowed to be used in a path since it starts with '.'",
 264                      name);
 265                 return false;
 266         }
 267         /* Does not contain a path-separator. */
 268         if (strchr(name, LTTNG_PATH_SEPARATOR)) {
 269                 WARN("Name \"%s\" is not allowed to be used in a path since it contains a path separator",
 270                      name);
 271                 return false;
 272         }
 273
 274         return true;
 275 }
 276
 277 /*
 278  * Create a new session by assigning a new session ID.
 279  *
 280  * Return allocated session or else NULL.
 281  */
 282 struct relay_session *session_create(const char *session_name,
 283                                      const char *hostname,
 284                                      const char *base_path,
 285                                      uint32_t live_timer,
 286                                      bool snapshot,
 287                                      const lttng_uuid& sessiond_uuid,
 288                                      const uint64_t *id_sessiond,
 289                                      const uint64_t *current_chunk_id,
 290                                      const time_t *creation_time,
 291                                      uint32_t major,
 292                                      uint32_t minor,
 293                                      bool session_name_contains_creation_time)
 294 {
 295         int ret;
 296         struct relay_session *session = nullptr;
 297
 298         LTTNG_ASSERT(session_name);
 299         LTTNG_ASSERT(hostname);
 300         LTTNG_ASSERT(base_path);
 301
 302         if (!is_name_path_safe(session_name)) {
 303                 ERR("Refusing to create session as the provided session name is not path-safe");
 304                 goto error;
 305         }
 306         if (!is_name_path_safe(hostname)) {
 307                 ERR("Refusing to create session as the provided hostname is not path-safe");
 308                 goto error;
 309         }
 310         if (strstr(base_path, "../")) {
 311                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"", base_path);
 312                 goto error;
 313         }
 314
 315         session = zmalloc<relay_session>();
 316         if (!session) {
 317                 PERROR("Failed to allocate session");
 318                 goto error;
 319         }
 320
 321         pthread_mutex_lock(&last_relay_session_id_lock);
 322         session->id = ++last_relay_session_id;
 323         pthread_mutex_unlock(&last_relay_session_id_lock);
 324
 325         lttng_ht_node_init_u64(&session->session_n, session->id);
 326         urcu_ref_init(&session->ref);
 327         CDS_INIT_LIST_HEAD(&session->recv_list);
 328         pthread_mutex_init(&session->lock, nullptr);
 329         pthread_mutex_init(&session->recv_list_lock, nullptr);
 330
 331         if (lttng_strncpy(session->session_name, session_name, sizeof(session->session_name))) {
 332                 WARN("Session name exceeds maximal allowed length");
 333                 goto error;
 334         }
 335         if (lttng_strncpy(session->hostname, hostname, sizeof(session->hostname))) {
 336                 WARN("Hostname exceeds maximal allowed length");
 337                 goto error;
 338         }
 339         if (lttng_strncpy(session->base_path, base_path, sizeof(session->base_path))) {
 340                 WARN("Base path exceeds maximal allowed length");
 341                 goto error;
 342         }
 343         if (creation_time) {
 344                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 345         } else {
 346                 LTTNG_OPTIONAL_SET(&session->creation_time, time(nullptr));
 347                 if (session->creation_time.value == (time_t) -1) {
 348                         PERROR("Failed to sample session creation time");
 349                         goto error;
 350                 }
 351         }
 352         session->session_name_contains_creation_time = session_name_contains_creation_time;
 353
 354         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 355         if (!session->ctf_traces_ht) {
 356                 goto error;
 357         }
 358
 359         session->major = major;
 360         session->minor = minor;
 361
 362         session->live_timer = live_timer;
 363         session->snapshot = snapshot;
 364         session->sessiond_uuid = sessiond_uuid;
 365
 366         if (id_sessiond) {
 367                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 368         }
 369
 370         if (major == 2 && minor >= 11) {
 371                 /* Only applies for 2.11+ peers using trace chunks. */
 372                 ret = init_session_output_path(session);
 373                 if (ret) {
 374                         goto error;
 375                 }
 376         }
 377
 378         ret = sessiond_trace_chunk_registry_session_created(sessiond_trace_chunk_registry,
 379                                                             sessiond_uuid);
 380         if (ret) {
 381                 goto error;
 382         }
 383
 384         if (id_sessiond && current_chunk_id) {
 385                 enum lttng_trace_chunk_status chunk_status;
 386                 struct lttng_directory_handle *session_output_directory;
 387
 388                 session->current_trace_chunk =
 389                         sessiond_trace_chunk_registry_get_chunk(sessiond_trace_chunk_registry,
 390                                                                 session->sessiond_uuid,
 391                                                                 session->id_sessiond.value,
 392                                                                 *current_chunk_id);
 393                 if (!session->current_trace_chunk) {
 394                         char uuid_str[LTTNG_UUID_STR_LEN];
 395
 396                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 397                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64
 398                             ", trace chunk id = %" PRIu64,
 399                             uuid_str,
 400                             *id_sessiond,
 401                             *current_chunk_id);
 402                         goto error;
 403                 }
 404
 405                 chunk_status = lttng_trace_chunk_get_session_output_directory_handle(
 406                         session->current_trace_chunk, &session_output_directory);
 407                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 408                         goto error;
 409                 }
 410
 411                 LTTNG_ASSERT(session_output_directory);
 412                 session->output_directory = session_output_directory;
 413         } else if (!id_sessiond) {
 414                 /*
 415                  * Pre-2.11 peers will not announce trace chunks. An
 416                  * anonymous trace chunk which will remain set for the
 417                  * duration of the session is created.
 418                  */
 419                 ret = session_set_anonymous_chunk(session);
 420                 if (ret) {
 421                         goto error;
 422                 }
 423         } else {
 424                 session->output_directory = session_create_output_directory_handle(session);
 425                 if (!session->output_directory) {
 426                         goto error;
 427                 }
 428         }
 429
 430         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 431         return session;
 432
 433 error:
 434         session_put(session);
 435         return nullptr;
 436 }
 437
 438 /* Should be called with RCU read-side lock held. */
 439 bool session_get(struct relay_session *session)
 440 {
 441         return urcu_ref_get_unless_zero(&session->ref);
 442 }
 443
 444 /*
 445  * Lookup a session within the session hash table using the session id
 446  * as key. A session reference is taken when a session is returned.
 447  * session_put() must be called on that session.
 448  *
 449  * Return session or NULL if not found.
 450  */
 451 struct relay_session *session_get_by_id(uint64_t id)
 452 {
 453         struct relay_session *session = nullptr;
 454         struct lttng_ht_node_u64 *node;
 455         struct lttng_ht_iter iter;
 456
 457         rcu_read_lock();
 458         lttng_ht_lookup(sessions_ht, &id, &iter);
 459         node = lttng_ht_iter_get_node_u64(&iter);
 460         if (!node) {
 461                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 462                 goto end;
 463         }
 464         session = lttng::utils::container_of(node, &relay_session::session_n);
 465         DBG("Session find by ID %" PRIu64 " id found", id);
 466         if (!session_get(session)) {
 467                 session = nullptr;
 468         }
 469 end:
 470         rcu_read_unlock();
 471         return session;
 472 }
 473
 474 /*
 475  * Check if any of the relay sessions originating from the same
 476  * session daemon session have the 'ongoing_rotation' state set.
 477  *
 478  * The caller must hold the lock of session.
 479  */
 480 bool session_has_ongoing_rotation(const struct relay_session *session)
 481 {
 482         bool ongoing_rotation = false;
 483         struct lttng_ht_iter iter;
 484         struct relay_session *iterated_session;
 485
 486         ASSERT_LOCKED(session->lock);
 487
 488         if (!session->id_sessiond.is_set) {
 489                 /*
 490                  * The peer that created this session is too old to
 491                  * support rotations; we can assume no rotations are ongoing.
 492                  */
 493                 goto end;
 494         }
 495
 496         if (session->ongoing_rotation) {
 497                 ongoing_rotation = true;
 498                 goto end;
 499         }
 500
 501         rcu_read_lock();
 502         /*
 503          * Sample the 'ongoing_rotation' status of all relay sessions that
 504          * originate from the same session daemon session.
 505          */
 506         cds_lfht_for_each_entry (sessions_ht->ht, &iter.iter, iterated_session, session_n.node) {
 507                 if (!session_get(iterated_session)) {
 508                         continue;
 509                 }
 510
 511                 if (session == iterated_session) {
 512                         /* Skip this session. */
 513                         goto next_session_no_unlock;
 514                 }
 515
 516                 pthread_mutex_lock(&iterated_session->lock);
 517
 518                 if (!iterated_session->id_sessiond.is_set) {
 519                         /*
 520                          * Session belongs to a peer that doesn't support
 521                          * rotations.
 522                          */
 523                         goto next_session;
 524                 }
 525
 526                 if (session->sessiond_uuid != iterated_session->sessiond_uuid) {
 527                         /* Sessions do not originate from the same sessiond. */
 528                         goto next_session;
 529                 }
 530
 531                 if (LTTNG_OPTIONAL_GET(session->id_sessiond) !=
 532                     LTTNG_OPTIONAL_GET(iterated_session->id_sessiond)) {
 533                         /*
 534                          * Sessions do not originate from the same sessiond
 535                          * session.
 536                          */
 537                         goto next_session;
 538                 }
 539
 540                 ongoing_rotation = iterated_session->ongoing_rotation;
 541
 542         next_session:
 543                 pthread_mutex_unlock(&iterated_session->lock);
 544         next_session_no_unlock:
 545                 session_put(iterated_session);
 546
 547                 if (ongoing_rotation) {
 548                         break;
 549                 }
 550         }
 551         rcu_read_unlock();
 552
 553 end:
 554         return ongoing_rotation;
 555 }
 556
 557 static void rcu_destroy_session(struct rcu_head *rcu_head)
 558 {
 559         struct relay_session *session = caa_container_of(rcu_head, struct relay_session, rcu_node);
 560         /*
 561          * Since each trace has a reference on the session, it means
 562          * that if we are at the point where we teardown the session, no
 563          * trace belonging to that session exist at this point.
 564          * Calling lttng_ht_destroy in call_rcu worker thread so we
 565          * don't hold the RCU read-side lock while calling it.
 566          */
 567         lttng_ht_destroy(session->ctf_traces_ht);
 568         free(session);
 569 }
 570
 571 /*
 572  * Delete session from the given hash table.
 573  *
 574  * Return lttng ht del error code being 0 on success and 1 on failure.
 575  */
 576 static int session_delete(struct relay_session *session)
 577 {
 578         struct lttng_ht_iter iter;
 579
 580         iter.iter.node = &session->session_n.node;
 581         return lttng_ht_del(sessions_ht, &iter);
 582 }
 583
 584 static void destroy_session(struct relay_session *session)
 585 {
 586         int ret;
 587
 588         ret = session_delete(session);
 589         LTTNG_ASSERT(!ret);
 590         lttng_trace_chunk_put(session->current_trace_chunk);
 591         session->current_trace_chunk = nullptr;
 592         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 593         session->pending_closure_trace_chunk = nullptr;
 594         ret = sessiond_trace_chunk_registry_session_destroyed(sessiond_trace_chunk_registry,
 595                                                               session->sessiond_uuid);
 596         LTTNG_ASSERT(!ret);
 597         lttng_directory_handle_put(session->output_directory);
 598         session->output_directory = nullptr;
 599         call_rcu(&session->rcu_node, rcu_destroy_session);
 600 }
 601
 602 static void session_release(struct urcu_ref *ref)
 603 {
 604         struct relay_session *session = lttng::utils::container_of(ref, &relay_session::ref);
 605
 606         destroy_session(session);
 607 }
 608
 609 void session_put(struct relay_session *session)
 610 {
 611         if (!session) {
 612                 return;
 613         }
 614         rcu_read_lock();
 615         urcu_ref_put(&session->ref, session_release);
 616         rcu_read_unlock();
 617 }
 618
 619 int session_close(struct relay_session *session)
 620 {
 621         int ret = 0;
 622         struct ctf_trace *trace;
 623         struct lttng_ht_iter iter;
 624         struct relay_stream *stream;
 625
 626         pthread_mutex_lock(&session->lock);
 627         DBG("closing session %" PRIu64 ": is conn already closed %d",
 628             session->id,
 629             session->connection_closed);
 630         session->connection_closed = true;
 631         pthread_mutex_unlock(&session->lock);
 632
 633         rcu_read_lock();
 634         cds_lfht_for_each_entry (session->ctf_traces_ht->ht, &iter.iter, trace, node.node) {
 635                 ret = ctf_trace_close(trace);
 636                 if (ret) {
 637                         goto rcu_unlock;
 638                 }
 639         }
 640         cds_list_for_each_entry_rcu(stream, &session->recv_list, recv_node)
 641         {
 642                 /* Close streams which have not been published yet. */
 643                 try_stream_close(stream);
 644         }
 645 rcu_unlock:
 646         rcu_read_unlock();
 647         if (ret) {
 648                 return ret;
 649         }
 650         /* Put self-reference from create. */
 651         session_put(session);
 652         return ret;
 653 }
 654
 655 int session_abort(struct relay_session *session)
 656 {
 657         int ret = 0;
 658
 659         if (!session) {
 660                 return 0;
 661         }
 662
 663         pthread_mutex_lock(&session->lock);
 664         DBG("aborting session %" PRIu64, session->id);
 665         session->aborted = true;
 666         pthread_mutex_unlock(&session->lock);
 667         return ret;
 668 }
 669
 670 void print_sessions()
 671 {
 672         struct lttng_ht_iter iter;
 673         struct relay_session *session;
 674
 675         if (!sessions_ht) {
 676                 return;
 677         }
 678
 679         rcu_read_lock();
 680         cds_lfht_for_each_entry (sessions_ht->ht, &iter.iter, session, session_n.node) {
 681                 if (!session_get(session)) {
 682                         continue;
 683                 }
 684                 DBG("session %p refcount %ld session %" PRIu64,
 685                     session,
 686                     session->ref.refcount,
 687                     session->id);
 688                 session_put(session);
 689         }
 690         rcu_read_unlock();
 691 }