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 <common/common.hpp>
  12 #include <common/compat/path.hpp>
  13 #include <common/fd-tracker/utils.hpp>
  14 #include <common/time.hpp>
  15 #include <common/utils.hpp>
  16 #include <common/uuid.hpp>
  17 #include <urcu/rculist.h>
  18
  19 #include <sys/stat.h>
  20
  21 #include "ctf-trace.hpp"
  22 #include "lttng-relayd.hpp"
  23 #include "session.hpp"
  24 #include "sessiond-trace-chunks.hpp"
  25 #include "stream.hpp"
  26 #include <common/defaults.hpp>
  27 #include "utils.hpp"
  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 = NULL;
  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,
  62                                 session->base_path);
  63         } else if (session->session_name_contains_creation_time) {
  64                 ret = asprintf(&session_directory, "%s/%s", session->hostname,
  65                                 session->session_name);
  66         } else {
  67                 char session_creation_datetime[DATETIME_STR_LEN];
  68
  69                 ret = time_to_datetime_str(
  70                                 LTTNG_OPTIONAL_GET(session->creation_time),
  71                                 session_creation_datetime,
  72                                 sizeof(session_creation_datetime));
  73                 if (ret) {
  74                         ERR("Failed to format session creation timestamp while initializing session output directory handle");
  75                         ret = -1;
  76                         goto end;
  77                 }
  78
  79                 ret = asprintf(&session_directory, "%s/%s-%s",
  80                                 session->hostname, 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(
 102                 struct relay_session *session)
 103 {
 104         /*
 105          * session_directory:
 106          *
 107          *   session_name/hostname-creation_time/base_path
 108          *
 109          * For session name including the datetime, use it as the complete name
 110          * since. Do not perform modification on it since the datetime is an
 111          * integral part of the name and how a user identify a session.
 112          */
 113         int ret = 0;
 114         char *session_directory = NULL;
 115         char creation_datetime[DATETIME_STR_LEN];
 116
 117         if (session->output_path[0] != '\0') {
 118                 /* output_path as been generated already */
 119                 goto end;
 120         }
 121
 122         ret = time_to_datetime_str(LTTNG_OPTIONAL_GET(session->creation_time),
 123                         creation_datetime, 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, "%s/%s-%s%s%s",
 131                         session->session_name, session->hostname,
 132                         creation_datetime,
 133                         session->base_path[0] != '\0' ? "/" : "",
 134                         session->base_path);
 135         if (ret < 0) {
 136                 PERROR("Failed to format session directory name");
 137                 goto end;
 138         }
 139
 140         if (strlen(session_directory) >= LTTNG_PATH_MAX) {
 141                 ERR("Session output directory exceeds maximal length");
 142                 ret = -1;
 143                 goto end;
 144         }
 145
 146         strcpy(session->output_path, session_directory);
 147         ret = 0;
 148
 149 end:
 150         free(session_directory);
 151         return ret;
 152 }
 153
 154 static int init_session_output_path(struct relay_session *session)
 155 {
 156         int ret;
 157
 158         switch (opt_group_output_by) {
 159         case RELAYD_GROUP_OUTPUT_BY_HOST:
 160                 ret = init_session_output_path_group_by_host(session);
 161                 break;
 162         case RELAYD_GROUP_OUTPUT_BY_SESSION:
 163                 ret = init_session_output_path_group_by_session(session);
 164                 break;
 165         case RELAYD_GROUP_OUTPUT_BY_UNKNOWN:
 166         default:
 167                 abort();
 168                 break;
 169         }
 170
 171         return ret;
 172 }
 173
 174 static struct lttng_directory_handle *session_create_output_directory_handle(
 175                 struct relay_session *session)
 176 {
 177         int ret;
 178         /*
 179          * relayd_output_path/session_directory
 180          * e.g. /home/user/lttng-traces/hostname/session_name
 181          */
 182         char *full_session_path = NULL;
 183         struct lttng_directory_handle *handle = NULL;
 184
 185         pthread_mutex_lock(&session->lock);
 186         full_session_path = create_output_path(session->output_path);
 187         if (!full_session_path) {
 188                 goto end;
 189         }
 190
 191         ret = utils_mkdir_recursive(
 192                         full_session_path, S_IRWXU | S_IRWXG, -1, -1);
 193         if (ret) {
 194                 ERR("Failed to create session output path \"%s\"",
 195                                 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 = NULL;
 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 = NULL;
 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 '.'", name);
 264                 return false;
 265         }
 266         /* Does not contain a path-separator. */
 267         if (strchr(name, LTTNG_PATH_SEPARATOR)) {
 268                 WARN("Name \"%s\" is not allowed to be used in a path since it contains a path separator", name);
 269                 return false;
 270         }
 271
 272         return true;
 273 }
 274
 275 /*
 276  * Create a new session by assigning a new session ID.
 277  *
 278  * Return allocated session or else NULL.
 279  */
 280 struct relay_session *session_create(const char *session_name,
 281                 const char *hostname, const char *base_path,
 282                 uint32_t live_timer,
 283                 bool snapshot,
 284                 const lttng_uuid& sessiond_uuid,
 285                 const uint64_t *id_sessiond,
 286                 const uint64_t *current_chunk_id,
 287                 const time_t *creation_time,
 288                 uint32_t major,
 289                 uint32_t minor,
 290                 bool session_name_contains_creation_time)
 291 {
 292         int ret;
 293         struct relay_session *session = NULL;
 294
 295         LTTNG_ASSERT(session_name);
 296         LTTNG_ASSERT(hostname);
 297         LTTNG_ASSERT(base_path);
 298
 299         if (!is_name_path_safe(session_name)) {
 300                 ERR("Refusing to create session as the provided session name is not path-safe");
 301                 goto error;
 302         }
 303         if (!is_name_path_safe(hostname)) {
 304                 ERR("Refusing to create session as the provided hostname is not path-safe");
 305                 goto error;
 306         }
 307         if (strstr(base_path, "../")) {
 308                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
 309                                 base_path);
 310                 goto error;
 311         }
 312
 313         session = zmalloc<relay_session>();
 314         if (!session) {
 315                 PERROR("Failed to allocate session");
 316                 goto error;
 317         }
 318
 319         pthread_mutex_lock(&last_relay_session_id_lock);
 320         session->id = ++last_relay_session_id;
 321         pthread_mutex_unlock(&last_relay_session_id_lock);
 322
 323         lttng_ht_node_init_u64(&session->session_n, session->id);
 324         urcu_ref_init(&session->ref);
 325         CDS_INIT_LIST_HEAD(&session->recv_list);
 326         pthread_mutex_init(&session->lock, NULL);
 327         pthread_mutex_init(&session->recv_list_lock, NULL);
 328
 329         if (lttng_strncpy(session->session_name, session_name,
 330                         sizeof(session->session_name))) {
 331                 WARN("Session name exceeds maximal allowed length");
 332                 goto error;
 333         }
 334         if (lttng_strncpy(session->hostname, hostname,
 335                         sizeof(session->hostname))) {
 336                 WARN("Hostname exceeds maximal allowed length");
 337                 goto error;
 338         }
 339         if (lttng_strncpy(session->base_path, base_path,
 340                         sizeof(session->base_path))) {
 341                 WARN("Base path exceeds maximal allowed length");
 342                 goto error;
 343         }
 344         if (creation_time) {
 345                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 346         } else {
 347                 LTTNG_OPTIONAL_SET(&session->creation_time, time(NULL));
 348                 if (session->creation_time.value == (time_t) -1) {
 349                         PERROR("Failed to sample session creation time");
 350                         goto error;
 351                 }
 352         }
 353         session->session_name_contains_creation_time =
 354                         session_name_contains_creation_time;
 355
 356         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 357         if (!session->ctf_traces_ht) {
 358                 goto error;
 359         }
 360
 361         session->major = major;
 362         session->minor = minor;
 363
 364         session->live_timer = live_timer;
 365         session->snapshot = snapshot;
 366         session->sessiond_uuid = sessiond_uuid;
 367
 368         if (id_sessiond) {
 369                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 370         }
 371
 372         if (major == 2 && minor >= 11) {
 373                 /* Only applies for 2.11+ peers using trace chunks. */
 374                 ret = init_session_output_path(session);
 375                 if (ret) {
 376                         goto error;
 377                 }
 378         }
 379
 380         ret = sessiond_trace_chunk_registry_session_created(
 381                         sessiond_trace_chunk_registry, sessiond_uuid);
 382         if (ret) {
 383                 goto error;
 384         }
 385
 386         if (id_sessiond && current_chunk_id) {
 387                 enum lttng_trace_chunk_status chunk_status;
 388                 struct lttng_directory_handle *session_output_directory;
 389
 390                 session->current_trace_chunk =
 391                                 sessiond_trace_chunk_registry_get_chunk(
 392                                         sessiond_trace_chunk_registry,
 393                                         session->sessiond_uuid,
 394                                         session->id_sessiond.value,
 395                                         *current_chunk_id);
 396                 if (!session->current_trace_chunk) {
 397                         char uuid_str[LTTNG_UUID_STR_LEN];
 398
 399                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 400                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 401                                         uuid_str, *id_sessiond,
 402                                         *current_chunk_id);
 403                         goto error;
 404                 }
 405
 406                 chunk_status = lttng_trace_chunk_get_session_output_directory_handle(
 407                                 session->current_trace_chunk,
 408                                 &session_output_directory);
 409                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 410                         goto error;
 411                 }
 412
 413                 LTTNG_ASSERT(session_output_directory);
 414                 session->output_directory = session_output_directory;
 415         } else if (!id_sessiond) {
 416                 /*
 417                  * Pre-2.11 peers will not announce trace chunks. An
 418                  * anonymous trace chunk which will remain set for the
 419                  * duration of the session is created.
 420                  */
 421                 ret = session_set_anonymous_chunk(session);
 422                 if (ret) {
 423                         goto error;
 424                 }
 425         } else {
 426                 session->output_directory =
 427                                 session_create_output_directory_handle(session);
 428                 if (!session->output_directory) {
 429                         goto error;
 430                 }
 431         }
 432
 433         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 434         return session;
 435
 436 error:
 437         session_put(session);
 438         return NULL;
 439 }
 440
 441 /* Should be called with RCU read-side lock held. */
 442 bool session_get(struct relay_session *session)
 443 {
 444         return urcu_ref_get_unless_zero(&session->ref);
 445 }
 446
 447 /*
 448  * Lookup a session within the session hash table using the session id
 449  * as key. A session reference is taken when a session is returned.
 450  * session_put() must be called on that session.
 451  *
 452  * Return session or NULL if not found.
 453  */
 454 struct relay_session *session_get_by_id(uint64_t id)
 455 {
 456         struct relay_session *session = NULL;
 457         struct lttng_ht_node_u64 *node;
 458         struct lttng_ht_iter iter;
 459
 460         rcu_read_lock();
 461         lttng_ht_lookup(sessions_ht, &id, &iter);
 462         node = lttng_ht_iter_get_node_u64(&iter);
 463         if (!node) {
 464                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 465                 goto end;
 466         }
 467         session = lttng::utils::container_of(node, &relay_session::session_n);
 468         DBG("Session find by ID %" PRIu64 " id found", id);
 469         if (!session_get(session)) {
 470                 session = NULL;
 471         }
 472 end:
 473         rcu_read_unlock();
 474         return session;
 475 }
 476
 477 /*
 478  * Check if any of the relay sessions originating from the same
 479  * session daemon session have the 'ongoing_rotation' state set.
 480  *
 481  * The caller must hold the lock of session.
 482  */
 483 bool session_has_ongoing_rotation(const struct relay_session *session)
 484 {
 485         bool ongoing_rotation = false;
 486         struct lttng_ht_iter iter;
 487         struct relay_session *iterated_session;
 488
 489         ASSERT_LOCKED(session->lock);
 490
 491         if (!session->id_sessiond.is_set) {
 492                 /*
 493                  * The peer that created this session is too old to
 494                  * support rotations; we can assume no rotations are ongoing.
 495                  */
 496                 goto end;
 497         }
 498
 499         if (session->ongoing_rotation) {
 500                 ongoing_rotation = true;
 501                 goto end;
 502         }
 503
 504         rcu_read_lock();
 505         /*
 506          * Sample the 'ongoing_rotation' status of all relay sessions that
 507          * originate from the same session daemon session.
 508          */
 509         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, iterated_session,
 510                         session_n.node) {
 511                 if (!session_get(iterated_session)) {
 512                         continue;
 513                 }
 514
 515                 if (session == iterated_session) {
 516                         /* Skip this session. */
 517                         goto next_session_no_unlock;
 518                 }
 519
 520                 pthread_mutex_lock(&iterated_session->lock);
 521
 522                 if (!iterated_session->id_sessiond.is_set) {
 523                         /*
 524                          * Session belongs to a peer that doesn't support
 525                          * rotations.
 526                          */
 527                         goto next_session;
 528                 }
 529
 530                 if (session->sessiond_uuid != iterated_session->sessiond_uuid) {
 531                         /* Sessions do not originate from the same sessiond. */
 532                         goto next_session;
 533                 }
 534
 535                 if (LTTNG_OPTIONAL_GET(session->id_sessiond) !=
 536                                 LTTNG_OPTIONAL_GET(iterated_session->id_sessiond)) {
 537                         /*
 538                          * Sessions do not originate from the same sessiond
 539                          * session.
 540                          */
 541                         goto next_session;
 542                 }
 543
 544                 ongoing_rotation = iterated_session->ongoing_rotation;
 545
 546 next_session:
 547                 pthread_mutex_unlock(&iterated_session->lock);
 548 next_session_no_unlock:
 549                 session_put(iterated_session);
 550
 551                 if (ongoing_rotation) {
 552                         break;
 553                 }
 554         }
 555         rcu_read_unlock();
 556
 557 end:
 558         return ongoing_rotation;
 559 }
 560
 561 static void rcu_destroy_session(struct rcu_head *rcu_head)
 562 {
 563         struct relay_session *session =
 564                         caa_container_of(rcu_head, struct relay_session,
 565                                 rcu_node);
 566         /*
 567          * Since each trace has a reference on the session, it means
 568          * that if we are at the point where we teardown the session, no
 569          * trace belonging to that session exist at this point.
 570          * Calling lttng_ht_destroy in call_rcu worker thread so we
 571          * don't hold the RCU read-side lock while calling it.
 572          */
 573         lttng_ht_destroy(session->ctf_traces_ht);
 574         free(session);
 575 }
 576
 577 /*
 578  * Delete session from the given hash table.
 579  *
 580  * Return lttng ht del error code being 0 on success and 1 on failure.
 581  */
 582 static int session_delete(struct relay_session *session)
 583 {
 584         struct lttng_ht_iter iter;
 585
 586         iter.iter.node = &session->session_n.node;
 587         return lttng_ht_del(sessions_ht, &iter);
 588 }
 589
 590
 591 static void destroy_session(struct relay_session *session)
 592 {
 593         int ret;
 594
 595         ret = session_delete(session);
 596         LTTNG_ASSERT(!ret);
 597         lttng_trace_chunk_put(session->current_trace_chunk);
 598         session->current_trace_chunk = NULL;
 599         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 600         session->pending_closure_trace_chunk = NULL;
 601         ret = sessiond_trace_chunk_registry_session_destroyed(
 602                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 603         LTTNG_ASSERT(!ret);
 604         lttng_directory_handle_put(session->output_directory);
 605         session->output_directory = NULL;
 606         call_rcu(&session->rcu_node, rcu_destroy_session);
 607 }
 608
 609 static void session_release(struct urcu_ref *ref)
 610 {
 611         struct relay_session *session =
 612                         lttng::utils::container_of(ref, &relay_session::ref);
 613
 614         destroy_session(session);
 615 }
 616
 617 void session_put(struct relay_session *session)
 618 {
 619         if (!session) {
 620                 return;
 621         }
 622         rcu_read_lock();
 623         urcu_ref_put(&session->ref, session_release);
 624         rcu_read_unlock();
 625 }
 626
 627 int session_close(struct relay_session *session)
 628 {
 629         int ret = 0;
 630         struct ctf_trace *trace;
 631         struct lttng_ht_iter iter;
 632         struct relay_stream *stream;
 633
 634         pthread_mutex_lock(&session->lock);
 635         DBG("closing session %" PRIu64 ": is conn already closed %d",
 636                         session->id, session->connection_closed);
 637         session->connection_closed = true;
 638         pthread_mutex_unlock(&session->lock);
 639
 640         rcu_read_lock();
 641         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 642                         &iter.iter, trace, node.node) {
 643                 ret = ctf_trace_close(trace);
 644                 if (ret) {
 645                         goto rcu_unlock;
 646                 }
 647         }
 648         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 649                         recv_node) {
 650                 /* Close streams which have not been published yet. */
 651                 try_stream_close(stream);
 652         }
 653 rcu_unlock:
 654         rcu_read_unlock();
 655         if (ret) {
 656                 return ret;
 657         }
 658         /* Put self-reference from create. */
 659         session_put(session);
 660         return ret;
 661 }
 662
 663 int session_abort(struct relay_session *session)
 664 {
 665         int ret = 0;
 666
 667         if (!session) {
 668                 return 0;
 669         }
 670
 671         pthread_mutex_lock(&session->lock);
 672         DBG("aborting session %" PRIu64, session->id);
 673         session->aborted = true;
 674         pthread_mutex_unlock(&session->lock);
 675         return ret;
 676 }
 677
 678 void print_sessions(void)
 679 {
 680         struct lttng_ht_iter iter;
 681         struct relay_session *session;
 682
 683         if (!sessions_ht) {
 684                 return;
 685         }
 686
 687         rcu_read_lock();
 688         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 689                         session_n.node) {
 690                 if (!session_get(session)) {
 691                         continue;
 692                 }
 693                 DBG("session %p refcount %ld session %" PRIu64,
 694                         session,
 695                         session->ref.refcount,
 696                         session->id);
 697                 session_put(session);
 698         }
 699         rcu_read_unlock();
 700 }