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 <sys/stat.h>
  27
  28 #include "ctf-trace.h"
  29 #include "lttng-relayd.h"
  30 #include "session.h"
  31 #include "sessiond-trace-chunks.h"
  32 #include "stream.h"
  33 #include <common/defaults.h>
  34 #include "utils.h"
  35
  36 /* Global session id used in the session creation. */
  37 static uint64_t last_relay_session_id;
  38 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
  39
  40 static int init_session_output_path(struct relay_session *session)
  41 {
  42         /*
  43          * session_directory:
  44          *
  45          * if base_path is \0'
  46          *   hostname/session_name
  47          * else
  48          *   hostname/base_path
  49          */
  50         char *session_directory = NULL;
  51         int ret = 0;
  52
  53         if (session->output_path[0] != '\0') {
  54                 goto end;
  55         }
  56         /*
  57          * If base path is set, it overrides the session name for the
  58          * session relative base path. No timestamp is appended if the
  59          * base path is overridden.
  60          *
  61          * If the session name already contains the creation time (e.g.
  62          * auto-<timestamp>, don't append yet another timestamp after
  63          * the session name in the generated path.
  64          *
  65          * Otherwise, generate the path with session_name-<timestamp>.
  66          */
  67         if (session->base_path[0] != '\0') {
  68                 ret = asprintf(&session_directory, "%s/%s", session->hostname,
  69                                 session->base_path);
  70         } else if (session->session_name_contains_creation_time) {
  71                 ret = asprintf(&session_directory, "%s/%s", session->hostname,
  72                                 session->session_name);
  73         } else {
  74                 char session_creation_datetime[16];
  75                 size_t strftime_ret;
  76                 struct tm *timeinfo;
  77                 time_t creation_time;
  78
  79                 /*
  80                  * The 2.11+ protocol guarantees that a creation time
  81                  * is provided for a session. This would indicate a
  82                  * protocol error or an improper use of this util.
  83                  */
  84                 if (!session->creation_time.is_set) {
  85                         ERR("Creation time missing for session \"%s\" (protocol error)",
  86                                         session->session_name);
  87                         ret = -1;
  88                         goto end;
  89                 }
  90                 creation_time = LTTNG_OPTIONAL_GET(session->creation_time);
  91
  92                 timeinfo = localtime(&creation_time);
  93                 if (!timeinfo) {
  94                         ERR("Failed to get timeinfo while initializing session output directory handle");
  95                         ret = -1;
  96                         goto end;
  97                 }
  98                 strftime_ret = strftime(session_creation_datetime,
  99                                 sizeof(session_creation_datetime),
 100                                 "%Y%m%d-%H%M%S", timeinfo);
 101                 if (strftime_ret == 0) {
 102                         ERR("Failed to format session creation timestamp while initializing session output directory handle");
 103                         ret = -1;
 104                         goto end;
 105                 }
 106                 ret = asprintf(&session_directory, "%s/%s-%s",
 107                                 session->hostname, session->session_name,
 108                                 session_creation_datetime);
 109         }
 110         if (ret < 0) {
 111                 PERROR("Failed to format session directory name");
 112                 goto end;
 113         }
 114
 115         if (strlen(session_directory) >= LTTNG_PATH_MAX) {
 116                 ERR("Session output directory exceeds maximal length");
 117                 ret = -1;
 118                 goto end;
 119         }
 120         strcpy(session->output_path, session_directory);
 121         ret = 0;
 122
 123 end:
 124         free(session_directory);
 125         return ret;
 126 }
 127
 128 static int session_set_anonymous_chunk(struct relay_session *session)
 129 {
 130         int ret = 0;
 131         struct lttng_trace_chunk *chunk = NULL;
 132         enum lttng_trace_chunk_status status;
 133         struct lttng_directory_handle output_directory;
 134
 135         ret = session_init_output_directory_handle(session, &output_directory);
 136         if (ret) {
 137                 goto end;
 138         }
 139
 140         chunk = lttng_trace_chunk_create_anonymous();
 141         if (!chunk) {
 142                 goto end;
 143         }
 144
 145         status = lttng_trace_chunk_set_credentials_current_user(chunk);
 146         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 147                 ret = -1;
 148                 goto end;
 149         }
 150
 151         status = lttng_trace_chunk_set_as_owner(chunk, &output_directory);
 152         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
 153                 ret = -1;
 154                 goto end;
 155         }
 156         session->current_trace_chunk = chunk;
 157         chunk = NULL;
 158 end:
 159         lttng_trace_chunk_put(chunk);
 160         lttng_directory_handle_fini(&output_directory);
 161         return ret;
 162 }
 163
 164 /*
 165  * Create a new session by assigning a new session ID.
 166  *
 167  * Return allocated session or else NULL.
 168  */
 169 struct relay_session *session_create(const char *session_name,
 170                 const char *hostname, const char *base_path,
 171                 uint32_t live_timer,
 172                 bool snapshot,
 173                 const lttng_uuid sessiond_uuid,
 174                 const uint64_t *id_sessiond,
 175                 const uint64_t *current_chunk_id,
 176                 const time_t *creation_time,
 177                 uint32_t major,
 178                 uint32_t minor,
 179                 bool session_name_contains_creation_time)
 180 {
 181         int ret;
 182         struct relay_session *session = NULL;
 183
 184         if (session_name && strstr(session_name, ".")) {
 185                 ERR("Illegal character in session name: \"%s\"",
 186                                 session_name);
 187                 goto error;
 188         }
 189         if (base_path && strstr(base_path, "../")) {
 190                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
 191                                 base_path);
 192                 goto error;
 193         }
 194         if (hostname && strstr(hostname, ".")) {
 195                 ERR("Invalid character in hostname: \"%s\"",
 196                                 hostname);
 197                 goto error;
 198         }
 199
 200         session = zmalloc(sizeof(*session));
 201         if (!session) {
 202                 PERROR("Failed to allocate session");
 203                 goto error;
 204         }
 205         if (lttng_strncpy(session->session_name, session_name,
 206                         sizeof(session->session_name))) {
 207                 WARN("Session name exceeds maximal allowed length");
 208                 goto error;
 209         }
 210         if (lttng_strncpy(session->hostname, hostname,
 211                         sizeof(session->hostname))) {
 212                 WARN("Hostname exceeds maximal allowed length");
 213                 goto error;
 214         }
 215         if (lttng_strncpy(session->base_path, base_path,
 216                         sizeof(session->base_path))) {
 217                 WARN("Base path exceeds maximal allowed length");
 218                 goto error;
 219         }
 220         if (creation_time) {
 221                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 222         }
 223         session->session_name_contains_creation_time =
 224                         session_name_contains_creation_time;
 225
 226         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 227         if (!session->ctf_traces_ht) {
 228                 goto error;
 229         }
 230
 231         pthread_mutex_lock(&last_relay_session_id_lock);
 232         session->id = ++last_relay_session_id;
 233         pthread_mutex_unlock(&last_relay_session_id_lock);
 234
 235         session->major = major;
 236         session->minor = minor;
 237         lttng_ht_node_init_u64(&session->session_n, session->id);
 238         urcu_ref_init(&session->ref);
 239         CDS_INIT_LIST_HEAD(&session->recv_list);
 240         pthread_mutex_init(&session->lock, NULL);
 241         pthread_mutex_init(&session->recv_list_lock, NULL);
 242
 243         session->live_timer = live_timer;
 244         session->snapshot = snapshot;
 245         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 246
 247         if (id_sessiond) {
 248                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 249         }
 250
 251         if (major == 2 && minor >= 11) {
 252                 /* Only applies for 2.11+ peers using trace chunks. */
 253                 ret = init_session_output_path(session);
 254                 if (ret) {
 255                         goto error;
 256                 }
 257         }
 258
 259         ret = sessiond_trace_chunk_registry_session_created(
 260                         sessiond_trace_chunk_registry, sessiond_uuid);
 261         if (ret) {
 262                 goto error;
 263         }
 264
 265         if (id_sessiond && current_chunk_id) {
 266                 session->current_trace_chunk =
 267                                 sessiond_trace_chunk_registry_get_chunk(
 268                                         sessiond_trace_chunk_registry,
 269                                         session->sessiond_uuid,
 270                                         session->id_sessiond.value,
 271                                         *current_chunk_id);
 272                 if (!session->current_trace_chunk) {
 273                         char uuid_str[UUID_STR_LEN];
 274
 275                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 276                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 277                                         uuid_str, *id_sessiond,
 278                                         *current_chunk_id);
 279                 }
 280         } else if (!id_sessiond) {
 281                 /*
 282                  * Pre-2.11 peers will not announce trace chunks. An
 283                  * anonymous trace chunk which will remain set for the
 284                  * duration of the session is created.
 285                  */
 286                 ret = session_set_anonymous_chunk(session);
 287                 if (ret) {
 288                         goto error;
 289                 }
 290         }
 291
 292         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 293         return session;
 294
 295 error:
 296         session_put(session);
 297         return NULL;
 298 }
 299
 300 /* Should be called with RCU read-side lock held. */
 301 bool session_get(struct relay_session *session)
 302 {
 303         return urcu_ref_get_unless_zero(&session->ref);
 304 }
 305
 306 /*
 307  * Lookup a session within the session hash table using the session id
 308  * as key. A session reference is taken when a session is returned.
 309  * session_put() must be called on that session.
 310  *
 311  * Return session or NULL if not found.
 312  */
 313 struct relay_session *session_get_by_id(uint64_t id)
 314 {
 315         struct relay_session *session = NULL;
 316         struct lttng_ht_node_u64 *node;
 317         struct lttng_ht_iter iter;
 318
 319         rcu_read_lock();
 320         lttng_ht_lookup(sessions_ht, &id, &iter);
 321         node = lttng_ht_iter_get_node_u64(&iter);
 322         if (!node) {
 323                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 324                 goto end;
 325         }
 326         session = caa_container_of(node, struct relay_session, session_n);
 327         DBG("Session find by ID %" PRIu64 " id found", id);
 328         if (!session_get(session)) {
 329                 session = NULL;
 330         }
 331 end:
 332         rcu_read_unlock();
 333         return session;
 334 }
 335
 336 static void rcu_destroy_session(struct rcu_head *rcu_head)
 337 {
 338         struct relay_session *session =
 339                         caa_container_of(rcu_head, struct relay_session,
 340                                 rcu_node);
 341         /*
 342          * Since each trace has a reference on the session, it means
 343          * that if we are at the point where we teardown the session, no
 344          * trace belonging to that session exist at this point.
 345          * Calling lttng_ht_destroy in call_rcu worker thread so we
 346          * don't hold the RCU read-side lock while calling it.
 347          */
 348         lttng_ht_destroy(session->ctf_traces_ht);
 349         free(session);
 350 }
 351
 352 /*
 353  * Delete session from the given hash table.
 354  *
 355  * Return lttng ht del error code being 0 on success and 1 on failure.
 356  */
 357 static int session_delete(struct relay_session *session)
 358 {
 359         struct lttng_ht_iter iter;
 360
 361         iter.iter.node = &session->session_n.node;
 362         return lttng_ht_del(sessions_ht, &iter);
 363 }
 364
 365
 366 static void destroy_session(struct relay_session *session)
 367 {
 368         int ret;
 369
 370         ret = session_delete(session);
 371         assert(!ret);
 372         lttng_trace_chunk_put(session->current_trace_chunk);
 373         session->current_trace_chunk = NULL;
 374         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 375         session->pending_closure_trace_chunk = NULL;
 376         ret = sessiond_trace_chunk_registry_session_destroyed(
 377                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 378         assert(!ret);
 379         call_rcu(&session->rcu_node, rcu_destroy_session);
 380 }
 381
 382 void session_release(struct urcu_ref *ref)
 383 {
 384         struct relay_session *session =
 385                         caa_container_of(ref, struct relay_session, ref);
 386
 387         destroy_session(session);
 388 }
 389
 390 void session_put(struct relay_session *session)
 391 {
 392         if (!session) {
 393                 return;
 394         }
 395         rcu_read_lock();
 396         urcu_ref_put(&session->ref, session_release);
 397         rcu_read_unlock();
 398 }
 399
 400 int session_close(struct relay_session *session)
 401 {
 402         int ret = 0;
 403         struct ctf_trace *trace;
 404         struct lttng_ht_iter iter;
 405         struct relay_stream *stream;
 406
 407         pthread_mutex_lock(&session->lock);
 408         DBG("closing session %" PRIu64 ": is conn already closed %d",
 409                         session->id, session->connection_closed);
 410         session->connection_closed = true;
 411         pthread_mutex_unlock(&session->lock);
 412
 413         rcu_read_lock();
 414         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 415                         &iter.iter, trace, node.node) {
 416                 ret = ctf_trace_close(trace);
 417                 if (ret) {
 418                         goto rcu_unlock;
 419                 }
 420         }
 421         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 422                         recv_node) {
 423                 /* Close streams which have not been published yet. */
 424                 try_stream_close(stream);
 425         }
 426 rcu_unlock:
 427         rcu_read_unlock();
 428         if (ret) {
 429                 return ret;
 430         }
 431         /* Put self-reference from create. */
 432         session_put(session);
 433         return ret;
 434 }
 435
 436 int session_abort(struct relay_session *session)
 437 {
 438         int ret = 0;
 439
 440         if (!session) {
 441                 return 0;
 442         }
 443
 444         pthread_mutex_lock(&session->lock);
 445         DBG("aborting session %" PRIu64, session->id);
 446         session->aborted = true;
 447         pthread_mutex_unlock(&session->lock);
 448         return ret;
 449 }
 450
 451 void print_sessions(void)
 452 {
 453         struct lttng_ht_iter iter;
 454         struct relay_session *session;
 455
 456         if (!sessions_ht) {
 457                 return;
 458         }
 459
 460         rcu_read_lock();
 461         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 462                         session_n.node) {
 463                 if (!session_get(session)) {
 464                         continue;
 465                 }
 466                 DBG("session %p refcount %ld session %" PRIu64,
 467                         session,
 468                         session->ref.refcount,
 469                         session->id);
 470                 session_put(session);
 471         }
 472         rcu_read_unlock();
 473 }
 474
 475 int session_init_output_directory_handle(struct relay_session *session,
 476                 struct lttng_directory_handle *handle)
 477 {
 478         int ret;
 479         /*
 480          * relayd_output_path/session_directory
 481          * e.g. /home/user/lttng-traces/hostname/session_name
 482          */
 483         char *full_session_path = NULL;
 484
 485         pthread_mutex_lock(&session->lock);
 486         full_session_path = create_output_path(session->output_path);
 487         if (!full_session_path) {
 488                 ret = -1;
 489                 goto end;
 490         }
 491
 492         ret = utils_mkdir_recursive(
 493                         full_session_path, S_IRWXU | S_IRWXG, -1, -1);
 494         if (ret) {
 495                 ERR("Failed to create session output path \"%s\"",
 496                                 full_session_path);
 497                 goto end;
 498         }
 499
 500         ret = lttng_directory_handle_init(handle, full_session_path);
 501         if (ret) {
 502                 goto end;
 503         }
 504 end:
 505         pthread_mutex_unlock(&session->lock);
 506         free(full_session_path);
 507         return ret;
 508 }