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         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
 320         pthread_mutex_lock(&last_relay_session_id_lock);
 321         session->id = ++last_relay_session_id;
 322         pthread_mutex_unlock(&last_relay_session_id_lock);
 323
 324         lttng_ht_node_init_u64(&session->session_n, session->id);
 325         urcu_ref_init(&session->ref);
 326         CDS_INIT_LIST_HEAD(&session->recv_list);
 327         pthread_mutex_init(&session->lock, NULL);
 328         pthread_mutex_init(&session->recv_list_lock, NULL);
 329
 330         if (lttng_strncpy(session->session_name, session_name,
 331                         sizeof(session->session_name))) {
 332                 WARN("Session name exceeds maximal allowed length");
 333                 goto error;
 334         }
 335         if (lttng_strncpy(session->hostname, hostname,
 336                         sizeof(session->hostname))) {
 337                 WARN("Hostname exceeds maximal allowed length");
 338                 goto error;
 339         }
 340         if (lttng_strncpy(session->base_path, base_path,
 341                         sizeof(session->base_path))) {
 342                 WARN("Base path exceeds maximal allowed length");
 343                 goto error;
 344         }
 345         if (creation_time) {
 346                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 347         }
 348         session->session_name_contains_creation_time =
 349                         session_name_contains_creation_time;
 350
 351         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 352         if (!session->ctf_traces_ht) {
 353                 goto error;
 354         }
 355
 356         session->major = major;
 357         session->minor = minor;
 358
 359         session->live_timer = live_timer;
 360         session->snapshot = snapshot;
 361         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 362
 363         if (id_sessiond) {
 364                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 365         }
 366
 367         if (major == 2 && minor >= 11) {
 368                 /* Only applies for 2.11+ peers using trace chunks. */
 369                 ret = init_session_output_path(session);
 370                 if (ret) {
 371                         goto error;
 372                 }
 373         }
 374
 375         ret = sessiond_trace_chunk_registry_session_created(
 376                         sessiond_trace_chunk_registry, sessiond_uuid);
 377         if (ret) {
 378                 goto error;
 379         }
 380
 381         if (id_sessiond && current_chunk_id) {
 382                 enum lttng_trace_chunk_status chunk_status;
 383                 struct lttng_directory_handle *session_output_directory;
 384
 385                 session->current_trace_chunk =
 386                                 sessiond_trace_chunk_registry_get_chunk(
 387                                         sessiond_trace_chunk_registry,
 388                                         session->sessiond_uuid,
 389                                         session->id_sessiond.value,
 390                                         *current_chunk_id);
 391                 if (!session->current_trace_chunk) {
 392                         char uuid_str[LTTNG_UUID_STR_LEN];
 393
 394                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 395                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 396                                         uuid_str, *id_sessiond,
 397                                         *current_chunk_id);
 398                         goto error;
 399                 }
 400
 401                 chunk_status = lttng_trace_chunk_get_session_output_directory_handle(
 402                                 session->current_trace_chunk,
 403                                 &session_output_directory);
 404                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 405                         goto error;
 406                 }
 407
 408                 assert(session_output_directory);
 409                 session->output_directory = session_output_directory;
 410         } else if (!id_sessiond) {
 411                 /*
 412                  * Pre-2.11 peers will not announce trace chunks. An
 413                  * anonymous trace chunk which will remain set for the
 414                  * duration of the session is created.
 415                  */
 416                 ret = session_set_anonymous_chunk(session);
 417                 if (ret) {
 418                         goto error;
 419                 }
 420         } else {
 421                 session->output_directory =
 422                                 session_create_output_directory_handle(session);
 423                 if (!session->output_directory) {
 424                         goto error;
 425                 }
 426         }
 427
 428         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 429         return session;
 430
 431 error:
 432         session_put(session);
 433         return NULL;
 434 }
 435
 436 /* Should be called with RCU read-side lock held. */
 437 bool session_get(struct relay_session *session)
 438 {
 439         return urcu_ref_get_unless_zero(&session->ref);
 440 }
 441
 442 /*
 443  * Lookup a session within the session hash table using the session id
 444  * as key. A session reference is taken when a session is returned.
 445  * session_put() must be called on that session.
 446  *
 447  * Return session or NULL if not found.
 448  */
 449 struct relay_session *session_get_by_id(uint64_t id)
 450 {
 451         struct relay_session *session = NULL;
 452         struct lttng_ht_node_u64 *node;
 453         struct lttng_ht_iter iter;
 454
 455         rcu_read_lock();
 456         lttng_ht_lookup(sessions_ht, &id, &iter);
 457         node = lttng_ht_iter_get_node_u64(&iter);
 458         if (!node) {
 459                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 460                 goto end;
 461         }
 462         session = caa_container_of(node, struct relay_session, session_n);
 463         DBG("Session find by ID %" PRIu64 " id found", id);
 464         if (!session_get(session)) {
 465                 session = NULL;
 466         }
 467 end:
 468         rcu_read_unlock();
 469         return session;
 470 }
 471
 472 static void rcu_destroy_session(struct rcu_head *rcu_head)
 473 {
 474         struct relay_session *session =
 475                         caa_container_of(rcu_head, struct relay_session,
 476                                 rcu_node);
 477         /*
 478          * Since each trace has a reference on the session, it means
 479          * that if we are at the point where we teardown the session, no
 480          * trace belonging to that session exist at this point.
 481          * Calling lttng_ht_destroy in call_rcu worker thread so we
 482          * don't hold the RCU read-side lock while calling it.
 483          */
 484         lttng_ht_destroy(session->ctf_traces_ht);
 485         free(session);
 486 }
 487
 488 /*
 489  * Delete session from the given hash table.
 490  *
 491  * Return lttng ht del error code being 0 on success and 1 on failure.
 492  */
 493 static int session_delete(struct relay_session *session)
 494 {
 495         struct lttng_ht_iter iter;
 496
 497         iter.iter.node = &session->session_n.node;
 498         return lttng_ht_del(sessions_ht, &iter);
 499 }
 500
 501
 502 static void destroy_session(struct relay_session *session)
 503 {
 504         int ret;
 505
 506         ret = session_delete(session);
 507         assert(!ret);
 508         lttng_trace_chunk_put(session->current_trace_chunk);
 509         session->current_trace_chunk = NULL;
 510         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 511         session->pending_closure_trace_chunk = NULL;
 512         ret = sessiond_trace_chunk_registry_session_destroyed(
 513                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 514         assert(!ret);
 515         lttng_directory_handle_put(session->output_directory);
 516         session->output_directory = NULL;
 517         call_rcu(&session->rcu_node, rcu_destroy_session);
 518 }
 519
 520 static void session_release(struct urcu_ref *ref)
 521 {
 522         struct relay_session *session =
 523                         caa_container_of(ref, struct relay_session, ref);
 524
 525         destroy_session(session);
 526 }
 527
 528 void session_put(struct relay_session *session)
 529 {
 530         if (!session) {
 531                 return;
 532         }
 533         rcu_read_lock();
 534         urcu_ref_put(&session->ref, session_release);
 535         rcu_read_unlock();
 536 }
 537
 538 int session_close(struct relay_session *session)
 539 {
 540         int ret = 0;
 541         struct ctf_trace *trace;
 542         struct lttng_ht_iter iter;
 543         struct relay_stream *stream;
 544
 545         pthread_mutex_lock(&session->lock);
 546         DBG("closing session %" PRIu64 ": is conn already closed %d",
 547                         session->id, session->connection_closed);
 548         session->connection_closed = true;
 549         pthread_mutex_unlock(&session->lock);
 550
 551         rcu_read_lock();
 552         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 553                         &iter.iter, trace, node.node) {
 554                 ret = ctf_trace_close(trace);
 555                 if (ret) {
 556                         goto rcu_unlock;
 557                 }
 558         }
 559         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 560                         recv_node) {
 561                 /* Close streams which have not been published yet. */
 562                 try_stream_close(stream);
 563         }
 564 rcu_unlock:
 565         rcu_read_unlock();
 566         if (ret) {
 567                 return ret;
 568         }
 569         /* Put self-reference from create. */
 570         session_put(session);
 571         return ret;
 572 }
 573
 574 int session_abort(struct relay_session *session)
 575 {
 576         int ret = 0;
 577
 578         if (!session) {
 579                 return 0;
 580         }
 581
 582         pthread_mutex_lock(&session->lock);
 583         DBG("aborting session %" PRIu64, session->id);
 584         session->aborted = true;
 585         pthread_mutex_unlock(&session->lock);
 586         return ret;
 587 }
 588
 589 void print_sessions(void)
 590 {
 591         struct lttng_ht_iter iter;
 592         struct relay_session *session;
 593
 594         if (!sessions_ht) {
 595                 return;
 596         }
 597
 598         rcu_read_lock();
 599         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 600                         session_n.node) {
 601                 if (!session_get(session)) {
 602                         continue;
 603                 }
 604                 DBG("session %p refcount %ld session %" PRIu64,
 605                         session,
 606                         session->ref.refcount,
 607                         session->id);
 608                 session_put(session);
 609         }
 610         rcu_read_unlock();
 611 }