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/compat/path.h>
  13 #include <common/fd-tracker/utils.h>
  14 #include <common/time.h>
  15 #include <common/utils.h>
  16 #include <common/uuid.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 = 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         assert(session_name);
 296         assert(hostname);
 297         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(sizeof(*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         }
 347         session->session_name_contains_creation_time =
 348                         session_name_contains_creation_time;
 349
 350         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 351         if (!session->ctf_traces_ht) {
 352                 goto error;
 353         }
 354
 355         session->major = major;
 356         session->minor = minor;
 357
 358         session->live_timer = live_timer;
 359         session->snapshot = snapshot;
 360         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 361
 362         if (id_sessiond) {
 363                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 364         }
 365
 366         if (major == 2 && minor >= 11) {
 367                 /* Only applies for 2.11+ peers using trace chunks. */
 368                 ret = init_session_output_path(session);
 369                 if (ret) {
 370                         goto error;
 371                 }
 372         }
 373
 374         ret = sessiond_trace_chunk_registry_session_created(
 375                         sessiond_trace_chunk_registry, sessiond_uuid);
 376         if (ret) {
 377                 goto error;
 378         }
 379
 380         if (id_sessiond && current_chunk_id) {
 381                 enum lttng_trace_chunk_status chunk_status;
 382                 struct lttng_directory_handle *session_output_directory;
 383
 384                 session->current_trace_chunk =
 385                                 sessiond_trace_chunk_registry_get_chunk(
 386                                         sessiond_trace_chunk_registry,
 387                                         session->sessiond_uuid,
 388                                         session->id_sessiond.value,
 389                                         *current_chunk_id);
 390                 if (!session->current_trace_chunk) {
 391                         char uuid_str[LTTNG_UUID_STR_LEN];
 392
 393                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 394                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 395                                         uuid_str, *id_sessiond,
 396                                         *current_chunk_id);
 397                         goto error;
 398                 }
 399
 400                 chunk_status = lttng_trace_chunk_get_session_output_directory_handle(
 401                                 session->current_trace_chunk,
 402                                 &session_output_directory);
 403                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 404                         goto error;
 405                 }
 406
 407                 assert(session_output_directory);
 408                 session->output_directory = session_output_directory;
 409         } else if (!id_sessiond) {
 410                 /*
 411                  * Pre-2.11 peers will not announce trace chunks. An
 412                  * anonymous trace chunk which will remain set for the
 413                  * duration of the session is created.
 414                  */
 415                 ret = session_set_anonymous_chunk(session);
 416                 if (ret) {
 417                         goto error;
 418                 }
 419         } else {
 420                 session->output_directory =
 421                                 session_create_output_directory_handle(session);
 422                 if (!session->output_directory) {
 423                         goto error;
 424                 }
 425         }
 426
 427         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 428         return session;
 429
 430 error:
 431         session_put(session);
 432         return NULL;
 433 }
 434
 435 /* Should be called with RCU read-side lock held. */
 436 bool session_get(struct relay_session *session)
 437 {
 438         return urcu_ref_get_unless_zero(&session->ref);
 439 }
 440
 441 /*
 442  * Lookup a session within the session hash table using the session id
 443  * as key. A session reference is taken when a session is returned.
 444  * session_put() must be called on that session.
 445  *
 446  * Return session or NULL if not found.
 447  */
 448 struct relay_session *session_get_by_id(uint64_t id)
 449 {
 450         struct relay_session *session = NULL;
 451         struct lttng_ht_node_u64 *node;
 452         struct lttng_ht_iter iter;
 453
 454         rcu_read_lock();
 455         lttng_ht_lookup(sessions_ht, &id, &iter);
 456         node = lttng_ht_iter_get_node_u64(&iter);
 457         if (!node) {
 458                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 459                 goto end;
 460         }
 461         session = caa_container_of(node, struct relay_session, session_n);
 462         DBG("Session find by ID %" PRIu64 " id found", id);
 463         if (!session_get(session)) {
 464                 session = NULL;
 465         }
 466 end:
 467         rcu_read_unlock();
 468         return session;
 469 }
 470
 471 static void rcu_destroy_session(struct rcu_head *rcu_head)
 472 {
 473         struct relay_session *session =
 474                         caa_container_of(rcu_head, struct relay_session,
 475                                 rcu_node);
 476         /*
 477          * Since each trace has a reference on the session, it means
 478          * that if we are at the point where we teardown the session, no
 479          * trace belonging to that session exist at this point.
 480          * Calling lttng_ht_destroy in call_rcu worker thread so we
 481          * don't hold the RCU read-side lock while calling it.
 482          */
 483         lttng_ht_destroy(session->ctf_traces_ht);
 484         free(session);
 485 }
 486
 487 /*
 488  * Delete session from the given hash table.
 489  *
 490  * Return lttng ht del error code being 0 on success and 1 on failure.
 491  */
 492 static int session_delete(struct relay_session *session)
 493 {
 494         struct lttng_ht_iter iter;
 495
 496         iter.iter.node = &session->session_n.node;
 497         return lttng_ht_del(sessions_ht, &iter);
 498 }
 499
 500
 501 static void destroy_session(struct relay_session *session)
 502 {
 503         int ret;
 504
 505         ret = session_delete(session);
 506         assert(!ret);
 507         lttng_trace_chunk_put(session->current_trace_chunk);
 508         session->current_trace_chunk = NULL;
 509         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 510         session->pending_closure_trace_chunk = NULL;
 511         ret = sessiond_trace_chunk_registry_session_destroyed(
 512                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 513         assert(!ret);
 514         lttng_directory_handle_put(session->output_directory);
 515         session->output_directory = NULL;
 516         call_rcu(&session->rcu_node, rcu_destroy_session);
 517 }
 518
 519 static void session_release(struct urcu_ref *ref)
 520 {
 521         struct relay_session *session =
 522                         caa_container_of(ref, struct relay_session, ref);
 523
 524         destroy_session(session);
 525 }
 526
 527 void session_put(struct relay_session *session)
 528 {
 529         if (!session) {
 530                 return;
 531         }
 532         rcu_read_lock();
 533         urcu_ref_put(&session->ref, session_release);
 534         rcu_read_unlock();
 535 }
 536
 537 int session_close(struct relay_session *session)
 538 {
 539         int ret = 0;
 540         struct ctf_trace *trace;
 541         struct lttng_ht_iter iter;
 542         struct relay_stream *stream;
 543
 544         pthread_mutex_lock(&session->lock);
 545         DBG("closing session %" PRIu64 ": is conn already closed %d",
 546                         session->id, session->connection_closed);
 547         session->connection_closed = true;
 548         pthread_mutex_unlock(&session->lock);
 549
 550         rcu_read_lock();
 551         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 552                         &iter.iter, trace, node.node) {
 553                 ret = ctf_trace_close(trace);
 554                 if (ret) {
 555                         goto rcu_unlock;
 556                 }
 557         }
 558         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 559                         recv_node) {
 560                 /* Close streams which have not been published yet. */
 561                 try_stream_close(stream);
 562         }
 563 rcu_unlock:
 564         rcu_read_unlock();
 565         if (ret) {
 566                 return ret;
 567         }
 568         /* Put self-reference from create. */
 569         session_put(session);
 570         return ret;
 571 }
 572
 573 int session_abort(struct relay_session *session)
 574 {
 575         int ret = 0;
 576
 577         if (!session) {
 578                 return 0;
 579         }
 580
 581         pthread_mutex_lock(&session->lock);
 582         DBG("aborting session %" PRIu64, session->id);
 583         session->aborted = true;
 584         pthread_mutex_unlock(&session->lock);
 585         return ret;
 586 }
 587
 588 void print_sessions(void)
 589 {
 590         struct lttng_ht_iter iter;
 591         struct relay_session *session;
 592
 593         if (!sessions_ht) {
 594                 return;
 595         }
 596
 597         rcu_read_lock();
 598         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 599                         session_n.node) {
 600                 if (!session_get(session)) {
 601                         continue;
 602                 }
 603                 DBG("session %p refcount %ld session %" PRIu64,
 604                         session,
 605                         session->ref.refcount,
 606                         session->id);
 607                 session_put(session);
 608         }
 609         rcu_read_unlock();
 610 }