src/bin/lttng-relayd/session.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #include <common/common.h>
  22 #include <common/utils.h>
  23 #include <common/compat/uuid.h>
  24 #include <urcu/rculist.h>
  25
  26 #include "ctf-trace.h"
  27 #include "lttng-relayd.h"
  28 #include "session.h"
  29 #include "sessiond-trace-chunks.h"
  30 #include "stream.h"
  31 #include <common/defaults.h>
  32
  33 /* Global session id used in the session creation. */
  34 static uint64_t last_relay_session_id;
  35 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
  36
  37 static int init_session_output_path(struct relay_session *session)
  38 {
  39         /*
  40          * session_directory:
  41          *
  42          * if base_path is \0'
  43          *   hostname/session_name
  44          * else
  45          *   hostname/base_path
  46          */
  47         char *session_directory = NULL;
  48         int ret = 0;
  49
  50         if (session->output_path[0] != '\0') {
  51                 goto end;
  52         }
  53         /*
  54          * If base path is set, it overrides the session name for the
  55          * session relative base path. No timestamp is appended if the
  56          * base path is overridden.
  57          *
  58          * If the session name already contains the creation time (e.g.
  59          * auto-<timestamp>, don't append yet another timestamp after
  60          * the session name in the generated path.
  61          *
  62          * Otherwise, generate the path with session_name-<timestamp>.
  63          */
  64         if (session->base_path[0] != '\0') {
  65                 ret = asprintf(&session_directory, "%s/%s", session->hostname,
  66                                 session->base_path);
  67         } else if (session->session_name_contains_creation_time) {
  68                 ret = asprintf(&session_directory, "%s/%s", session->hostname,
  69                                 session->session_name);
  70         } else {
  71                 char session_creation_datetime[16];
  72                 size_t strftime_ret;
  73                 struct tm *timeinfo;
  74                 time_t creation_time;
  75
  76                 /*
  77                  * The 2.11+ protocol guarantees that a creation time
  78                  * is provided for a session. This would indicate a
  79                  * protocol error or an improper use of this util.
  80                  */
  81                 if (!session->creation_time.is_set) {
  82                         ERR("Creation time missing for session \"%s\" (protocol error)",
  83                                         session->session_name);
  84                         ret = -1;
  85                         goto end;
  86                 }
  87                 creation_time = LTTNG_OPTIONAL_GET(session->creation_time);
  88
  89                 timeinfo = localtime(&creation_time);
  90                 if (!timeinfo) {
  91                         ERR("Failed to get timeinfo while initializing session output directory handle");
  92                         ret = -1;
  93                         goto end;
  94                 }
  95                 strftime_ret = strftime(session_creation_datetime,
  96                                 sizeof(session_creation_datetime),
  97                                 "%Y%m%d-%H%M%S", timeinfo);
  98                 if (strftime_ret == 0) {
  99                         ERR("Failed to format session creation timestamp while initializing session output directory handle");
 100                         ret = -1;
 101                         goto end;
 102                 }
 103                 ret = asprintf(&session_directory, "%s/%s-%s",
 104                                 session->hostname, session->session_name,
 105                                 session_creation_datetime);
 106         }
 107         if (ret < 0) {
 108                 PERROR("Failed to format session directory name");
 109                 goto end;
 110         }
 111
 112         if (strlen(session_directory) >= LTTNG_PATH_MAX) {
 113                 ERR("Session output directory exceeds maximal length");
 114                 ret = -1;
 115                 goto end;
 116         }
 117         strcpy(session->output_path, session_directory);
 118         ret = 0;
 119
 120 end:
 121         free(session_directory);
 122         return ret;
 123 }
 124
 125 static int session_set_anonymous_chunk(struct relay_session *session)
 126 {
 127         int ret = 0;
 128         struct lttng_trace_chunk *chunk = NULL;
 129         enum lttng_trace_chunk_status status;
 130         struct lttng_directory_handle output_directory;
 131         char *output_path;
 132         bool output_path_allocated = false;
 133
 134         if (!opt_output_path) {
 135                 /* No output path defined */
 136                 const char *home_dir = utils_get_home_dir();
 137                 if (!home_dir) {
 138                         ERR("Home path not found."
 139                                         " Please specify an output path using -o, --output PATH");
 140                         ret = -1;
 141                         goto end;
 142                 }
 143                 ret = asprintf(&output_path, "%s/%s", home_dir, DEFAULT_TRACE_DIR_NAME);
 144                 if (ret < 0) {
 145                         PERROR("asprintf trace dir name");
 146                         ret = -1;
 147                         goto end;
 148                 }
 149                 output_path_allocated = true;
 150         } else {
 151                 output_path = opt_output_path;
 152                 output_path_allocated = false;
 153         }
 154
 155         ret = lttng_directory_handle_init(&output_directory, output_path);
 156         if (ret) {
 157                 goto end;
 158         }
 159
 160         chunk = lttng_trace_chunk_create_anonymous();
 161         if (!chunk) {
 162                 goto end;
 163         }
 164
 165         status = lttng_trace_chunk_set_credentials_current_user(chunk);
 166         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 167                 ret = -1;
 168                 goto end;
 169         }
 170
 171         status = lttng_trace_chunk_set_as_owner(chunk, &output_directory);
 172         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 173                 ret = -1;
 174                 goto end;
 175         }
 176         session->current_trace_chunk = chunk;
 177         chunk = NULL;
 178 end:
 179         lttng_trace_chunk_put(chunk);
 180         lttng_directory_handle_fini(&output_directory);
 181         if (output_path_allocated) {
 182                 free(output_path);
 183         }
 184         return ret;
 185 }
 186
 187 /*
 188  * Create a new session by assigning a new session ID.
 189  *
 190  * Return allocated session or else NULL.
 191  */
 192 struct relay_session *session_create(const char *session_name,
 193                 const char *hostname, const char *base_path,
 194                 uint32_t live_timer,
 195                 bool snapshot,
 196                 const lttng_uuid sessiond_uuid,
 197                 const uint64_t *id_sessiond,
 198                 const uint64_t *current_chunk_id,
 199                 const time_t *creation_time,
 200                 uint32_t major,
 201                 uint32_t minor,
 202                 bool session_name_contains_creation_time)
 203 {
 204         int ret;
 205         struct relay_session *session = NULL;
 206
 207         if (session_name && strstr(session_name, ".")) {
 208                 ERR("Illegal character in session name: \"%s\"",
 209                                 session_name);
 210                 goto error;
 211         }
 212         if (base_path && strstr(base_path, "../")) {
 213                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
 214                                 base_path);
 215                 goto error;
 216         }
 217         if (hostname && strstr(hostname, ".")) {
 218                 ERR("Invalid character in hostname: \"%s\"",
 219                                 hostname);
 220                 goto error;
 221         }
 222
 223         session = zmalloc(sizeof(*session));
 224         if (!session) {
 225                 PERROR("Failed to allocate session");
 226                 goto error;
 227         }
 228         if (lttng_strncpy(session->session_name, session_name,
 229                         sizeof(session->session_name))) {
 230                 WARN("Session name exceeds maximal allowed length");
 231                 goto error;
 232         }
 233         if (lttng_strncpy(session->hostname, hostname,
 234                         sizeof(session->hostname))) {
 235                 WARN("Hostname exceeds maximal allowed length");
 236                 goto error;
 237         }
 238         if (lttng_strncpy(session->base_path, base_path,
 239                         sizeof(session->base_path))) {
 240                 WARN("Base path exceeds maximal allowed length");
 241                 goto error;
 242         }
 243         if (creation_time) {
 244                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 245         }
 246         session->session_name_contains_creation_time =
 247                         session_name_contains_creation_time;
 248
 249         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 250         if (!session->ctf_traces_ht) {
 251                 goto error;
 252         }
 253
 254         pthread_mutex_lock(&last_relay_session_id_lock);
 255         session->id = ++last_relay_session_id;
 256         pthread_mutex_unlock(&last_relay_session_id_lock);
 257
 258         session->major = major;
 259         session->minor = minor;
 260         lttng_ht_node_init_u64(&session->session_n, session->id);
 261         urcu_ref_init(&session->ref);
 262         CDS_INIT_LIST_HEAD(&session->recv_list);
 263         pthread_mutex_init(&session->lock, NULL);
 264         pthread_mutex_init(&session->recv_list_lock, NULL);
 265
 266         session->live_timer = live_timer;
 267         session->snapshot = snapshot;
 268         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 269
 270         if (id_sessiond) {
 271                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 272         }
 273
 274         ret = init_session_output_path(session);
 275         if (ret) {
 276                 goto error;
 277         }
 278         ret = sessiond_trace_chunk_registry_session_created(
 279                         sessiond_trace_chunk_registry, sessiond_uuid);
 280         if (ret) {
 281                 goto error;
 282         }
 283
 284         if (id_sessiond && current_chunk_id) {
 285                 session->current_trace_chunk =
 286                                 sessiond_trace_chunk_registry_get_chunk(
 287                                         sessiond_trace_chunk_registry,
 288                                         session->sessiond_uuid,
 289                                         session->id_sessiond.value,
 290                                         *current_chunk_id);
 291                 if (!session->current_trace_chunk) {
 292                         char uuid_str[UUID_STR_LEN];
 293
 294                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 295                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 296                                         uuid_str, *id_sessiond,
 297                                         *current_chunk_id);
 298                 }
 299         } else if (!id_sessiond) {
 300                 /*
 301                  * Pre-2.11 peers will not announce trace chunks. An
 302                  * anonymous trace chunk which will remain set for the
 303                  * duration of the session is created.
 304                  */
 305                 ret = session_set_anonymous_chunk(session);
 306                 if (ret) {
 307                         goto error;
 308                 }
 309         }
 310
 311         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 312         return session;
 313
 314 error:
 315         session_put(session);
 316         return NULL;
 317 }
 318
 319 /* Should be called with RCU read-side lock held. */
 320 bool session_get(struct relay_session *session)
 321 {
 322         return urcu_ref_get_unless_zero(&session->ref);
 323 }
 324
 325 /*
 326  * Lookup a session within the session hash table using the session id
 327  * as key. A session reference is taken when a session is returned.
 328  * session_put() must be called on that session.
 329  *
 330  * Return session or NULL if not found.
 331  */
 332 struct relay_session *session_get_by_id(uint64_t id)
 333 {
 334         struct relay_session *session = NULL;
 335         struct lttng_ht_node_u64 *node;
 336         struct lttng_ht_iter iter;
 337
 338         rcu_read_lock();
 339         lttng_ht_lookup(sessions_ht, &id, &iter);
 340         node = lttng_ht_iter_get_node_u64(&iter);
 341         if (!node) {
 342                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 343                 goto end;
 344         }
 345         session = caa_container_of(node, struct relay_session, session_n);
 346         DBG("Session find by ID %" PRIu64 " id found", id);
 347         if (!session_get(session)) {
 348                 session = NULL;
 349         }
 350 end:
 351         rcu_read_unlock();
 352         return session;
 353 }
 354
 355 static void rcu_destroy_session(struct rcu_head *rcu_head)
 356 {
 357         struct relay_session *session =
 358                         caa_container_of(rcu_head, struct relay_session,
 359                                 rcu_node);
 360         /*
 361          * Since each trace has a reference on the session, it means
 362          * that if we are at the point where we teardown the session, no
 363          * trace belonging to that session exist at this point.
 364          * Calling lttng_ht_destroy in call_rcu worker thread so we
 365          * don't hold the RCU read-side lock while calling it.
 366          */
 367         lttng_ht_destroy(session->ctf_traces_ht);
 368         free(session);
 369 }
 370
 371 /*
 372  * Delete session from the given hash table.
 373  *
 374  * Return lttng ht del error code being 0 on success and 1 on failure.
 375  */
 376 static int session_delete(struct relay_session *session)
 377 {
 378         struct lttng_ht_iter iter;
 379
 380         iter.iter.node = &session->session_n.node;
 381         return lttng_ht_del(sessions_ht, &iter);
 382 }
 383
 384
 385 static void destroy_session(struct relay_session *session)
 386 {
 387         int ret;
 388
 389         ret = session_delete(session);
 390         assert(!ret);
 391         lttng_trace_chunk_put(session->current_trace_chunk);
 392         session->current_trace_chunk = NULL;
 393         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 394         session->pending_closure_trace_chunk = NULL;
 395         ret = sessiond_trace_chunk_registry_session_destroyed(
 396                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 397         assert(!ret);
 398         call_rcu(&session->rcu_node, rcu_destroy_session);
 399 }
 400
 401 void session_release(struct urcu_ref *ref)
 402 {
 403         struct relay_session *session =
 404                         caa_container_of(ref, struct relay_session, ref);
 405
 406         destroy_session(session);
 407 }
 408
 409 void session_put(struct relay_session *session)
 410 {
 411         rcu_read_lock();
 412         urcu_ref_put(&session->ref, session_release);
 413         rcu_read_unlock();
 414 }
 415
 416 int session_close(struct relay_session *session)
 417 {
 418         int ret = 0;
 419         struct ctf_trace *trace;
 420         struct lttng_ht_iter iter;
 421         struct relay_stream *stream;
 422
 423         pthread_mutex_lock(&session->lock);
 424         DBG("closing session %" PRIu64 ": is conn already closed %d",
 425                         session->id, session->connection_closed);
 426         session->connection_closed = true;
 427         pthread_mutex_unlock(&session->lock);
 428
 429         rcu_read_lock();
 430         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 431                         &iter.iter, trace, node.node) {
 432                 ret = ctf_trace_close(trace);
 433                 if (ret) {
 434                         goto rcu_unlock;
 435                 }
 436         }
 437         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 438                         recv_node) {
 439                 /* Close streams which have not been published yet. */
 440                 try_stream_close(stream);
 441         }
 442 rcu_unlock:
 443         rcu_read_unlock();
 444         if (ret) {
 445                 return ret;
 446         }
 447         /* Put self-reference from create. */
 448         session_put(session);
 449         return ret;
 450 }
 451
 452 int session_abort(struct relay_session *session)
 453 {
 454         int ret = 0;
 455
 456         if (!session) {
 457                 return 0;
 458         }
 459
 460         pthread_mutex_lock(&session->lock);
 461         DBG("aborting session %" PRIu64, session->id);
 462         session->aborted = true;
 463         pthread_mutex_unlock(&session->lock);
 464         return ret;
 465 }
 466
 467 void print_sessions(void)
 468 {
 469         struct lttng_ht_iter iter;
 470         struct relay_session *session;
 471
 472         if (!sessions_ht) {
 473                 return;
 474         }
 475
 476         rcu_read_lock();
 477         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 478                         session_n.node) {
 479                 if (!session_get(session)) {
 480                         continue;
 481                 }
 482                 DBG("session %p refcount %ld session %" PRIu64,
 483                         session,
 484                         session->ref.refcount,
 485                         session->id);
 486                 session_put(session);
 487         }
 488         rcu_read_unlock();
 489 }