src/bin/lttng-relayd/session.c

   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.h>
  12 #include <common/uuid.h>
  13 #include <common/time.h>
  14 #include <common/utils.h>
  15 #include <common/uuid.h>
  16 #include <common/compat/path.h>
  17 #include <urcu/rculist.h>
  18
  19 #include <sys/stat.h>
  20
  21 #include "ctf-trace.h"
  22 #include "lttng-relayd.h"
  23 #include "session.h"
  24 #include "sessiond-trace-chunks.h"
  25 #include "stream.h"
  26 #include <common/defaults.h>
  27 #include "utils.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 = 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 = lttng_directory_handle_create(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         status = lttng_trace_chunk_set_credentials_current_user(chunk);
 224         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 225                 ret = -1;
 226                 goto end;
 227         }
 228
 229         status = lttng_trace_chunk_set_as_owner(chunk, output_directory);
 230         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 231                 ret = -1;
 232                 goto end;
 233         }
 234
 235         lttng_trace_chunk_set_fd_tracker(chunk, the_fd_tracker);
 236         output_directory = NULL;
 237         session->current_trace_chunk = chunk;
 238         chunk = NULL;
 239 end:
 240         lttng_trace_chunk_put(chunk);
 241         lttng_directory_handle_put(output_directory);
 242         return ret;
 243 }
 244
 245 /*
 246  * Check if a name is safe to use in a path.
 247  *
 248  * A name that is deemed "path-safe":
 249  *   - Does not contains a path separator (/ or \, platform dependant),
 250  *   - Does not start with a '.' (hidden file/folder),
 251  *   - Is not empty.
 252  */
 253 static bool is_name_path_safe(const char *name)
 254 {
 255         const size_t name_len = strlen(name);
 256
 257         /* Not empty. */
 258         if (name_len == 0) {
 259                 WARN("An empty name is not allowed to be used in a path");
 260                 return false;
 261         }
 262         /* Does not start with '.'. */
 263         if (name[0] == '.') {
 264                 WARN("Name \"%s\" is not allowed to be used in a path since it starts with '.'", 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", name);
 270                 return false;
 271         }
 272
 273         return true;
 274 }
 275
 276 /*
 277  * Create a new session by assigning a new session ID.
 278  *
 279  * Return allocated session or else NULL.
 280  */
 281 struct relay_session *session_create(const char *session_name,
 282                 const char *hostname, const char *base_path,
 283                 uint32_t live_timer,
 284                 bool snapshot,
 285                 const lttng_uuid sessiond_uuid,
 286                 const uint64_t *id_sessiond,
 287                 const uint64_t *current_chunk_id,
 288                 const time_t *creation_time,
 289                 uint32_t major,
 290                 uint32_t minor,
 291                 bool session_name_contains_creation_time)
 292 {
 293         int ret;
 294         struct relay_session *session = NULL;
 295
 296         assert(session_name);
 297         assert(hostname);
 298         assert(base_path);
 299
 300         if (!is_name_path_safe(session_name)) {
 301                 ERR("Refusing to create session as the provided session name is not path-safe");
 302                 goto error;
 303         }
 304         if (!is_name_path_safe(hostname)) {
 305                 ERR("Refusing to create session as the provided hostname is not path-safe");
 306                 goto error;
 307         }
 308         if (strstr(base_path, "../")) {
 309                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
 310                                 base_path);
 311                 goto error;
 312         }
 313
 314         session = zmalloc(sizeof(*session));
 315         if (!session) {
 316                 PERROR("Failed to allocate session");
 317                 goto error;
 318         }
 319         if (lttng_strncpy(session->session_name, session_name,
 320                         sizeof(session->session_name))) {
 321                 WARN("Session name exceeds maximal allowed length");
 322                 goto error;
 323         }
 324         if (lttng_strncpy(session->hostname, hostname,
 325                         sizeof(session->hostname))) {
 326                 WARN("Hostname exceeds maximal allowed length");
 327                 goto error;
 328         }
 329         if (lttng_strncpy(session->base_path, base_path,
 330                         sizeof(session->base_path))) {
 331                 WARN("Base path exceeds maximal allowed length");
 332                 goto error;
 333         }
 334         if (creation_time) {
 335                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 336         }
 337         session->session_name_contains_creation_time =
 338                         session_name_contains_creation_time;
 339
 340         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 341         if (!session->ctf_traces_ht) {
 342                 goto error;
 343         }
 344
 345         pthread_mutex_lock(&last_relay_session_id_lock);
 346         session->id = ++last_relay_session_id;
 347         pthread_mutex_unlock(&last_relay_session_id_lock);
 348
 349         session->major = major;
 350         session->minor = minor;
 351         lttng_ht_node_init_u64(&session->session_n, session->id);
 352         urcu_ref_init(&session->ref);
 353         CDS_INIT_LIST_HEAD(&session->recv_list);
 354         pthread_mutex_init(&session->lock, NULL);
 355         pthread_mutex_init(&session->recv_list_lock, NULL);
 356
 357         session->live_timer = live_timer;
 358         session->snapshot = snapshot;
 359         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 360
 361         if (id_sessiond) {
 362                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 363         }
 364
 365         if (major == 2 && minor >= 11) {
 366                 /* Only applies for 2.11+ peers using trace chunks. */
 367                 ret = init_session_output_path(session);
 368                 if (ret) {
 369                         goto error;
 370                 }
 371         }
 372
 373         ret = sessiond_trace_chunk_registry_session_created(
 374                         sessiond_trace_chunk_registry, sessiond_uuid);
 375         if (ret) {
 376                 goto error;
 377         }
 378
 379         if (id_sessiond && current_chunk_id) {
 380                 enum lttng_trace_chunk_status chunk_status;
 381                 struct lttng_directory_handle *session_output_directory;
 382
 383                 session->current_trace_chunk =
 384                                 sessiond_trace_chunk_registry_get_chunk(
 385                                         sessiond_trace_chunk_registry,
 386                                         session->sessiond_uuid,
 387                                         session->id_sessiond.value,
 388                                         *current_chunk_id);
 389                 if (!session->current_trace_chunk) {
 390                         char uuid_str[LTTNG_UUID_STR_LEN];
 391
 392                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 393                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 394                                         uuid_str, *id_sessiond,
 395                                         *current_chunk_id);
 396                         goto error;
 397                 }
 398
 399                 chunk_status = lttng_trace_chunk_get_session_output_directory_handle(
 400                                 session->current_trace_chunk,
 401                                 &session_output_directory);
 402                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 403                         goto error;
 404                 }
 405
 406                 assert(session_output_directory);
 407                 session->output_directory = session_output_directory;
 408         } else if (!id_sessiond) {
 409                 /*
 410                  * Pre-2.11 peers will not announce trace chunks. An
 411                  * anonymous trace chunk which will remain set for the
 412                  * duration of the session is created.
 413                  */
 414                 ret = session_set_anonymous_chunk(session);
 415                 if (ret) {
 416                         goto error;
 417                 }
 418         } else {
 419                 session->output_directory =
 420                                 session_create_output_directory_handle(session);
 421                 if (!session->output_directory) {
 422                         goto error;
 423                 }
 424         }
 425
 426         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 427         return session;
 428
 429 error:
 430         session_put(session);
 431         return NULL;
 432 }
 433
 434 /* Should be called with RCU read-side lock held. */
 435 bool session_get(struct relay_session *session)
 436 {
 437         return urcu_ref_get_unless_zero(&session->ref);
 438 }
 439
 440 /*
 441  * Lookup a session within the session hash table using the session id
 442  * as key. A session reference is taken when a session is returned.
 443  * session_put() must be called on that session.
 444  *
 445  * Return session or NULL if not found.
 446  */
 447 struct relay_session *session_get_by_id(uint64_t id)
 448 {
 449         struct relay_session *session = NULL;
 450         struct lttng_ht_node_u64 *node;
 451         struct lttng_ht_iter iter;
 452
 453         rcu_read_lock();
 454         lttng_ht_lookup(sessions_ht, &id, &iter);
 455         node = lttng_ht_iter_get_node_u64(&iter);
 456         if (!node) {
 457                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 458                 goto end;
 459         }
 460         session = caa_container_of(node, struct relay_session, session_n);
 461         DBG("Session find by ID %" PRIu64 " id found", id);
 462         if (!session_get(session)) {
 463                 session = NULL;
 464         }
 465 end:
 466         rcu_read_unlock();
 467         return session;
 468 }
 469
 470 static void rcu_destroy_session(struct rcu_head *rcu_head)
 471 {
 472         struct relay_session *session =
 473                         caa_container_of(rcu_head, struct relay_session,
 474                                 rcu_node);
 475         /*
 476          * Since each trace has a reference on the session, it means
 477          * that if we are at the point where we teardown the session, no
 478          * trace belonging to that session exist at this point.
 479          * Calling lttng_ht_destroy in call_rcu worker thread so we
 480          * don't hold the RCU read-side lock while calling it.
 481          */
 482         lttng_ht_destroy(session->ctf_traces_ht);
 483         free(session);
 484 }
 485
 486 /*
 487  * Delete session from the given hash table.
 488  *
 489  * Return lttng ht del error code being 0 on success and 1 on failure.
 490  */
 491 static int session_delete(struct relay_session *session)
 492 {
 493         struct lttng_ht_iter iter;
 494
 495         iter.iter.node = &session->session_n.node;
 496         return lttng_ht_del(sessions_ht, &iter);
 497 }
 498
 499
 500 static void destroy_session(struct relay_session *session)
 501 {
 502         int ret;
 503
 504         ret = session_delete(session);
 505         assert(!ret);
 506         lttng_trace_chunk_put(session->current_trace_chunk);
 507         session->current_trace_chunk = NULL;
 508         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 509         session->pending_closure_trace_chunk = NULL;
 510         ret = sessiond_trace_chunk_registry_session_destroyed(
 511                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 512         assert(!ret);
 513         lttng_directory_handle_put(session->output_directory);
 514         session->output_directory = NULL;
 515         call_rcu(&session->rcu_node, rcu_destroy_session);
 516 }
 517
 518 static void session_release(struct urcu_ref *ref)
 519 {
 520         struct relay_session *session =
 521                         caa_container_of(ref, struct relay_session, ref);
 522
 523         destroy_session(session);
 524 }
 525
 526 void session_put(struct relay_session *session)
 527 {
 528         if (!session) {
 529                 return;
 530         }
 531         rcu_read_lock();
 532         urcu_ref_put(&session->ref, session_release);
 533         rcu_read_unlock();
 534 }
 535
 536 int session_close(struct relay_session *session)
 537 {
 538         int ret = 0;
 539         struct ctf_trace *trace;
 540         struct lttng_ht_iter iter;
 541         struct relay_stream *stream;
 542
 543         pthread_mutex_lock(&session->lock);
 544         DBG("closing session %" PRIu64 ": is conn already closed %d",
 545                         session->id, session->connection_closed);
 546         session->connection_closed = true;
 547         pthread_mutex_unlock(&session->lock);
 548
 549         rcu_read_lock();
 550         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 551                         &iter.iter, trace, node.node) {
 552                 ret = ctf_trace_close(trace);
 553                 if (ret) {
 554                         goto rcu_unlock;
 555                 }
 556         }
 557         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 558                         recv_node) {
 559                 /* Close streams which have not been published yet. */
 560                 try_stream_close(stream);
 561         }
 562 rcu_unlock:
 563         rcu_read_unlock();
 564         if (ret) {
 565                 return ret;
 566         }
 567         /* Put self-reference from create. */
 568         session_put(session);
 569         return ret;
 570 }
 571
 572 int session_abort(struct relay_session *session)
 573 {
 574         int ret = 0;
 575
 576         if (!session) {
 577                 return 0;
 578         }
 579
 580         pthread_mutex_lock(&session->lock);
 581         DBG("aborting session %" PRIu64, session->id);
 582         session->aborted = true;
 583         pthread_mutex_unlock(&session->lock);
 584         return ret;
 585 }
 586
 587 void print_sessions(void)
 588 {
 589         struct lttng_ht_iter iter;
 590         struct relay_session *session;
 591
 592         if (!sessions_ht) {
 593                 return;
 594         }
 595
 596         rcu_read_lock();
 597         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 598                         session_n.node) {
 599                 if (!session_get(session)) {
 600                         continue;
 601                 }
 602                 DBG("session %p refcount %ld session %" PRIu64,
 603                         session,
 604                         session->ref.refcount,
 605                         session->id);
 606                 session_put(session);
 607         }
 608         rcu_read_unlock();
 609 }