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
  32 /* Global session id used in the session creation. */
  33 static uint64_t last_relay_session_id;
  34 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
  35
  36 static int session_set_anonymous_chunk(struct relay_session *session)
  37 {
  38         int ret = 0;
  39         struct lttng_trace_chunk *chunk = NULL;
  40         enum lttng_trace_chunk_status status;
  41         struct lttng_directory_handle output_directory;
  42         const char *base_path = opt_output_path;
  43
  44         if (base_path == NULL) {
  45                 /* No output path defined */
  46                 base_path = utils_get_home_dir();
  47                 if (base_path == NULL) {
  48                         ERR("Home path not found.\n \
  49                                         Please specify an output path using -o, --output PATH");
  50                         ret = -1;
  51                         goto end;
  52                 }
  53         }
  54
  55         ret = lttng_directory_handle_init(&output_directory, base_path);
  56         if (ret) {
  57                 goto end;
  58         }
  59
  60         chunk = lttng_trace_chunk_create_anonymous();
  61         if (!chunk) {
  62                 goto end;
  63         }
  64
  65         status = lttng_trace_chunk_set_credentials_current_user(chunk);
  66         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
  67                 ret = -1;
  68                 goto end;
  69         }
  70
  71         status = lttng_trace_chunk_set_as_owner(chunk, &output_directory);
  72         if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
  73                 ret = -1;
  74                 goto end;
  75         }
  76         session->current_trace_chunk = chunk;
  77         chunk = NULL;
  78 end:
  79         lttng_trace_chunk_put(chunk);
  80         lttng_directory_handle_fini(&output_directory);
  81         return ret;
  82 }
  83
  84 /*
  85  * Create a new session by assigning a new session ID.
  86  *
  87  * Return allocated session or else NULL.
  88  */
  89 struct relay_session *session_create(const char *session_name,
  90                 const char *hostname, const char *base_path,
  91                 uint32_t live_timer,
  92                 bool snapshot,
  93                 const lttng_uuid sessiond_uuid,
  94                 const uint64_t *id_sessiond,
  95                 const uint64_t *current_chunk_id,
  96                 const time_t *creation_time,
  97                 uint32_t major,
  98                 uint32_t minor)
  99 {
 100         int ret;
 101         struct relay_session *session = NULL;
 102
 103         if (session_name && strstr(session_name, ".")) {
 104                 ERR("Illegal character in session name: \"%s\"",
 105                                 session_name);
 106                 goto error;
 107         }
 108         if (base_path && strstr(base_path, "../")) {
 109                 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
 110                                 base_path);
 111                 goto error;
 112         }
 113         if (hostname && strstr(hostname, ".")) {
 114                 ERR("Invalid character in hostname: \"%s\"",
 115                                 hostname);
 116                 goto error;
 117         }
 118
 119         session = zmalloc(sizeof(*session));
 120         if (!session) {
 121                 PERROR("Failed to allocate session");
 122                 goto error;
 123         }
 124         if (lttng_strncpy(session->session_name, session_name,
 125                         sizeof(session->session_name))) {
 126                 WARN("Session name exceeds maximal allowed length");
 127                 goto error;
 128         }
 129         if (lttng_strncpy(session->hostname, hostname,
 130                         sizeof(session->hostname))) {
 131                 WARN("Hostname exceeds maximal allowed length");
 132                 goto error;
 133         }
 134         if (lttng_strncpy(session->base_path, base_path,
 135                         sizeof(session->base_path))) {
 136                 WARN("Base path exceeds maximal allowed length");
 137                 goto error;
 138         }
 139
 140         session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 141         if (!session->ctf_traces_ht) {
 142                 goto error;
 143         }
 144
 145         pthread_mutex_lock(&last_relay_session_id_lock);
 146         session->id = ++last_relay_session_id;
 147         pthread_mutex_unlock(&last_relay_session_id_lock);
 148
 149         session->major = major;
 150         session->minor = minor;
 151         lttng_ht_node_init_u64(&session->session_n, session->id);
 152         urcu_ref_init(&session->ref);
 153         CDS_INIT_LIST_HEAD(&session->recv_list);
 154         pthread_mutex_init(&session->lock, NULL);
 155         pthread_mutex_init(&session->recv_list_lock, NULL);
 156
 157         session->live_timer = live_timer;
 158         session->snapshot = snapshot;
 159         lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
 160
 161         if (id_sessiond) {
 162                 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
 163         }
 164
 165         ret = sessiond_trace_chunk_registry_session_created(
 166                         sessiond_trace_chunk_registry, sessiond_uuid);
 167         if (ret) {
 168                 goto error;
 169         }
 170
 171         if (id_sessiond && current_chunk_id) {
 172                 session->current_trace_chunk =
 173                                 sessiond_trace_chunk_registry_get_chunk(
 174                                         sessiond_trace_chunk_registry,
 175                                         session->sessiond_uuid,
 176                                         session->id_sessiond.value,
 177                                         *current_chunk_id);
 178                 if (!session->current_trace_chunk) {
 179                         char uuid_str[UUID_STR_LEN];
 180
 181                         lttng_uuid_to_str(sessiond_uuid, uuid_str);
 182                         ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
 183                                         uuid_str, *id_sessiond,
 184                                         *current_chunk_id);
 185                 }
 186         } else if (!id_sessiond) {
 187                 /*
 188                  * Pre-2.11 peers will not announce trace chunks. An
 189                  * anonymous trace chunk which will remain set for the
 190                  * duration of the session is created.
 191                  */
 192                 ret = session_set_anonymous_chunk(session);
 193                 if (ret) {
 194                         goto error;
 195                 }
 196         }
 197
 198         lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
 199         if (creation_time) {
 200                 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
 201         }
 202         return session;
 203
 204 error:
 205         session_put(session);
 206         return NULL;
 207 }
 208
 209 /* Should be called with RCU read-side lock held. */
 210 bool session_get(struct relay_session *session)
 211 {
 212         return urcu_ref_get_unless_zero(&session->ref);
 213 }
 214
 215 /*
 216  * Lookup a session within the session hash table using the session id
 217  * as key. A session reference is taken when a session is returned.
 218  * session_put() must be called on that session.
 219  *
 220  * Return session or NULL if not found.
 221  */
 222 struct relay_session *session_get_by_id(uint64_t id)
 223 {
 224         struct relay_session *session = NULL;
 225         struct lttng_ht_node_u64 *node;
 226         struct lttng_ht_iter iter;
 227
 228         rcu_read_lock();
 229         lttng_ht_lookup(sessions_ht, &id, &iter);
 230         node = lttng_ht_iter_get_node_u64(&iter);
 231         if (!node) {
 232                 DBG("Session find by ID %" PRIu64 " id NOT found", id);
 233                 goto end;
 234         }
 235         session = caa_container_of(node, struct relay_session, session_n);
 236         DBG("Session find by ID %" PRIu64 " id found", id);
 237         if (!session_get(session)) {
 238                 session = NULL;
 239         }
 240 end:
 241         rcu_read_unlock();
 242         return session;
 243 }
 244
 245 static void rcu_destroy_session(struct rcu_head *rcu_head)
 246 {
 247         struct relay_session *session =
 248                         caa_container_of(rcu_head, struct relay_session,
 249                                 rcu_node);
 250         /*
 251          * Since each trace has a reference on the session, it means
 252          * that if we are at the point where we teardown the session, no
 253          * trace belonging to that session exist at this point.
 254          * Calling lttng_ht_destroy in call_rcu worker thread so we
 255          * don't hold the RCU read-side lock while calling it.
 256          */
 257         lttng_ht_destroy(session->ctf_traces_ht);
 258         free(session);
 259 }
 260
 261 /*
 262  * Delete session from the given hash table.
 263  *
 264  * Return lttng ht del error code being 0 on success and 1 on failure.
 265  */
 266 static int session_delete(struct relay_session *session)
 267 {
 268         struct lttng_ht_iter iter;
 269
 270         iter.iter.node = &session->session_n.node;
 271         return lttng_ht_del(sessions_ht, &iter);
 272 }
 273
 274
 275 static void destroy_session(struct relay_session *session)
 276 {
 277         int ret;
 278
 279         ret = session_delete(session);
 280         assert(!ret);
 281         lttng_trace_chunk_put(session->current_trace_chunk);
 282         session->current_trace_chunk = NULL;
 283         lttng_trace_chunk_put(session->pending_closure_trace_chunk);
 284         session->pending_closure_trace_chunk = NULL;
 285         ret = sessiond_trace_chunk_registry_session_destroyed(
 286                         sessiond_trace_chunk_registry, session->sessiond_uuid);
 287         assert(!ret);
 288         call_rcu(&session->rcu_node, rcu_destroy_session);
 289 }
 290
 291 void session_release(struct urcu_ref *ref)
 292 {
 293         struct relay_session *session =
 294                         caa_container_of(ref, struct relay_session, ref);
 295
 296         destroy_session(session);
 297 }
 298
 299 void session_put(struct relay_session *session)
 300 {
 301         rcu_read_lock();
 302         urcu_ref_put(&session->ref, session_release);
 303         rcu_read_unlock();
 304 }
 305
 306 int session_close(struct relay_session *session)
 307 {
 308         int ret = 0;
 309         struct ctf_trace *trace;
 310         struct lttng_ht_iter iter;
 311         struct relay_stream *stream;
 312
 313         pthread_mutex_lock(&session->lock);
 314         DBG("closing session %" PRIu64 ": is conn already closed %d",
 315                         session->id, session->connection_closed);
 316         session->connection_closed = true;
 317         pthread_mutex_unlock(&session->lock);
 318
 319         rcu_read_lock();
 320         cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
 321                         &iter.iter, trace, node.node) {
 322                 ret = ctf_trace_close(trace);
 323                 if (ret) {
 324                         goto rcu_unlock;
 325                 }
 326         }
 327         cds_list_for_each_entry_rcu(stream, &session->recv_list,
 328                         recv_node) {
 329                 /* Close streams which have not been published yet. */
 330                 try_stream_close(stream);
 331         }
 332 rcu_unlock:
 333         rcu_read_unlock();
 334         if (ret) {
 335                 return ret;
 336         }
 337         /* Put self-reference from create. */
 338         session_put(session);
 339         return ret;
 340 }
 341
 342 int session_abort(struct relay_session *session)
 343 {
 344         int ret = 0;
 345
 346         if (!session) {
 347                 return 0;
 348         }
 349
 350         pthread_mutex_lock(&session->lock);
 351         DBG("aborting session %" PRIu64, session->id);
 352         session->aborted = true;
 353         pthread_mutex_unlock(&session->lock);
 354         return ret;
 355 }
 356
 357 void print_sessions(void)
 358 {
 359         struct lttng_ht_iter iter;
 360         struct relay_session *session;
 361
 362         if (!sessions_ht) {
 363                 return;
 364         }
 365
 366         rcu_read_lock();
 367         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 368                         session_n.node) {
 369                 if (!session_get(session)) {
 370                         continue;
 371                 }
 372                 DBG("session %p refcount %ld session %" PRIu64,
 373                         session,
 374                         session->ref.refcount,
 375                         session->id);
 376                 session_put(session);
 377         }
 378         rcu_read_unlock();
 379 }