src/bin/lttng-relayd/live.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
   7  * it under the terms of the GNU General Public License, version 2 only,
   8  * as 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
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #include <getopt.h>
  22 #include <grp.h>
  23 #include <limits.h>
  24 #include <pthread.h>
  25 #include <signal.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/mman.h>
  30 #include <sys/mount.h>
  31 #include <sys/resource.h>
  32 #include <sys/socket.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36 #include <inttypes.h>
  37 #include <urcu/futex.h>
  38 #include <urcu/uatomic.h>
  39 #include <urcu/rculist.h>
  40 #include <unistd.h>
  41 #include <fcntl.h>
  42
  43 #include <lttng/lttng.h>
  44 #include <common/common.h>
  45 #include <common/compat/poll.h>
  46 #include <common/compat/socket.h>
  47 #include <common/compat/endian.h>
  48 #include <common/defaults.h>
  49 #include <common/futex.h>
  50 #include <common/index/index.h>
  51 #include <common/sessiond-comm/sessiond-comm.h>
  52 #include <common/sessiond-comm/inet.h>
  53 #include <common/sessiond-comm/relayd.h>
  54 #include <common/uri.h>
  55 #include <common/utils.h>
  56
  57 #include "cmd.h"
  58 #include "live.h"
  59 #include "lttng-relayd.h"
  60 #include "utils.h"
  61 #include "health-relayd.h"
  62 #include "testpoint.h"
  63 #include "viewer-stream.h"
  64 #include "stream.h"
  65 #include "session.h"
  66 #include "ctf-trace.h"
  67 #include "connection.h"
  68 #include "viewer-session.h"
  69
  70 #define SESSION_BUF_DEFAULT_COUNT       16
  71
  72 static struct lttng_uri *live_uri;
  73
  74 /*
  75  * This pipe is used to inform the worker thread that a command is queued and
  76  * ready to be processed.
  77  */
  78 static int live_conn_pipe[2] = { -1, -1 };
  79
  80 /* Shared between threads */
  81 static int live_dispatch_thread_exit;
  82
  83 static pthread_t live_listener_thread;
  84 static pthread_t live_dispatcher_thread;
  85 static pthread_t live_worker_thread;
  86
  87 /*
  88  * Relay command queue.
  89  *
  90  * The live_thread_listener and live_thread_dispatcher communicate with this
  91  * queue.
  92  */
  93 static struct relay_conn_queue viewer_conn_queue;
  94
  95 static uint64_t last_relay_viewer_session_id;
  96 static pthread_mutex_t last_relay_viewer_session_id_lock =
  97                 PTHREAD_MUTEX_INITIALIZER;
  98
  99 /*
 100  * Cleanup the daemon
 101  */
 102 static
 103 void cleanup_relayd_live(void)
 104 {
 105         DBG("Cleaning up");
 106
 107         free(live_uri);
 108 }
 109
 110 /*
 111  * Receive a request buffer using a given socket, destination allocated buffer
 112  * of length size.
 113  *
 114  * Return the size of the received message or else a negative value on error
 115  * with errno being set by recvmsg() syscall.
 116  */
 117 static
 118 ssize_t recv_request(struct lttcomm_sock *sock, void *buf, size_t size)
 119 {
 120         ssize_t ret;
 121
 122         ret = sock->ops->recvmsg(sock, buf, size, 0);
 123         if (ret < 0 || ret != size) {
 124                 if (ret == 0) {
 125                         /* Orderly shutdown. Not necessary to print an error. */
 126                         DBG("Socket %d did an orderly shutdown", sock->fd);
 127                 } else {
 128                         ERR("Relay failed to receive request.");
 129                 }
 130                 ret = -1;
 131         }
 132
 133         return ret;
 134 }
 135
 136 /*
 137  * Send a response buffer using a given socket, source allocated buffer of
 138  * length size.
 139  *
 140  * Return the size of the sent message or else a negative value on error with
 141  * errno being set by sendmsg() syscall.
 142  */
 143 static
 144 ssize_t send_response(struct lttcomm_sock *sock, void *buf, size_t size)
 145 {
 146         ssize_t ret;
 147
 148         ret = sock->ops->sendmsg(sock, buf, size, 0);
 149         if (ret < 0) {
 150                 ERR("Relayd failed to send response.");
 151         }
 152
 153         return ret;
 154 }
 155
 156 /*
 157  * Atomically check if new streams got added in one of the sessions attached
 158  * and reset the flag to 0.
 159  *
 160  * Returns 1 if new streams got added, 0 if nothing changed, a negative value
 161  * on error.
 162  */
 163 static
 164 int check_new_streams(struct relay_connection *conn)
 165 {
 166         struct relay_session *session;
 167         unsigned long current_val;
 168         int ret = 0;
 169
 170         if (!conn->viewer_session) {
 171                 goto end;
 172         }
 173         rcu_read_lock();
 174         cds_list_for_each_entry_rcu(session,
 175                         &conn->viewer_session->session_list,
 176                         viewer_session_node) {
 177                 if (!session_get(session)) {
 178                         continue;
 179                 }
 180                 current_val = uatomic_cmpxchg(&session->new_streams, 1, 0);
 181                 ret = current_val;
 182                 session_put(session);
 183                 if (ret == 1) {
 184                         goto end;
 185                 }
 186         }
 187 end:
 188         rcu_read_unlock();
 189         return ret;
 190 }
 191
 192 /*
 193  * Send viewer streams to the given socket. The ignore_sent_flag indicates if
 194  * this function should ignore the sent flag or not.
 195  *
 196  * Return 0 on success or else a negative value.
 197  */
 198 static
 199 ssize_t send_viewer_streams(struct lttcomm_sock *sock,
 200                 struct relay_session *session, unsigned int ignore_sent_flag)
 201 {
 202         ssize_t ret;
 203         struct lttng_viewer_stream send_stream;
 204         struct lttng_ht_iter iter;
 205         struct relay_viewer_stream *vstream;
 206
 207         rcu_read_lock();
 208
 209         cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
 210                         stream_n.node) {
 211                 struct ctf_trace *ctf_trace;
 212
 213                 health_code_update();
 214
 215                 if (!viewer_stream_get(vstream)) {
 216                         continue;
 217                 }
 218
 219                 pthread_mutex_lock(&vstream->stream->lock);
 220                 /* Ignore if not the same session. */
 221                 if (vstream->stream->trace->session->id != session->id ||
 222                                 (!ignore_sent_flag && vstream->sent_flag)) {
 223                         pthread_mutex_unlock(&vstream->stream->lock);
 224                         viewer_stream_put(vstream);
 225                         continue;
 226                 }
 227
 228                 ctf_trace = vstream->stream->trace;
 229                 send_stream.id = htobe64(vstream->stream->stream_handle);
 230                 send_stream.ctf_trace_id = htobe64(ctf_trace->id);
 231                 send_stream.metadata_flag = htobe32(
 232                                 vstream->stream->is_metadata);
 233                 if (lttng_strncpy(send_stream.path_name, vstream->path_name,
 234                                 sizeof(send_stream.path_name))) {
 235                         pthread_mutex_unlock(&vstream->stream->lock);
 236                         viewer_stream_put(vstream);
 237                         ret = -1;       /* Error. */
 238                         goto end_unlock;
 239                 }
 240                 if (lttng_strncpy(send_stream.channel_name,
 241                                 vstream->channel_name,
 242                                 sizeof(send_stream.channel_name))) {
 243                         pthread_mutex_unlock(&vstream->stream->lock);
 244                         viewer_stream_put(vstream);
 245                         ret = -1;       /* Error. */
 246                         goto end_unlock;
 247                 }
 248
 249                 DBG("Sending stream %" PRIu64 " to viewer",
 250                                 vstream->stream->stream_handle);
 251                 vstream->sent_flag = 1;
 252                 pthread_mutex_unlock(&vstream->stream->lock);
 253
 254                 ret = send_response(sock, &send_stream, sizeof(send_stream));
 255                 viewer_stream_put(vstream);
 256                 if (ret < 0) {
 257                         goto end_unlock;
 258                 }
 259         }
 260
 261         ret = 0;
 262
 263 end_unlock:
 264         rcu_read_unlock();
 265         return ret;
 266 }
 267
 268 /*
 269  * Create every viewer stream possible for the given session with the seek
 270  * type. Three counters *can* be return which are in order the total amount of
 271  * viewer stream of the session, the number of unsent stream and the number of
 272  * stream created. Those counters can be NULL and thus will be ignored.
 273  *
 274  * Return 0 on success or else a negative value.
 275  */
 276 static
 277 int make_viewer_streams(struct relay_session *session,
 278                 enum lttng_viewer_seek seek_t, uint32_t *nb_total, uint32_t *nb_unsent,
 279                 uint32_t *nb_created, bool *closed)
 280 {
 281         int ret;
 282         struct lttng_ht_iter iter;
 283         struct ctf_trace *ctf_trace;
 284
 285         assert(session);
 286
 287         /*
 288          * Hold the session lock to ensure that we see either none or
 289          * all initial streams for a session, but no intermediate state.
 290          */
 291         pthread_mutex_lock(&session->lock);
 292
 293         if (session->connection_closed) {
 294                 *closed = true;
 295         }
 296
 297         /*
 298          * Create viewer streams for relay streams that are ready to be
 299          * used for a the given session id only.
 300          */
 301         rcu_read_lock();
 302         cds_lfht_for_each_entry(session->ctf_traces_ht->ht, &iter.iter, ctf_trace,
 303                         node.node) {
 304                 struct relay_stream *stream;
 305
 306                 health_code_update();
 307
 308                 if (!ctf_trace_get(ctf_trace)) {
 309                         continue;
 310                 }
 311
 312                 cds_list_for_each_entry_rcu(stream, &ctf_trace->stream_list, stream_node) {
 313                         struct relay_viewer_stream *vstream;
 314
 315                         if (!stream_get(stream)) {
 316                                 continue;
 317                         }
 318                         /*
 319                          * stream published is protected by the session lock.
 320                          */
 321                         if (!stream->published) {
 322                                 goto next;
 323                         }
 324                         vstream = viewer_stream_get_by_id(stream->stream_handle);
 325                         if (!vstream) {
 326                                 vstream = viewer_stream_create(stream, seek_t);
 327                                 if (!vstream) {
 328                                         ret = -1;
 329                                         ctf_trace_put(ctf_trace);
 330                                         stream_put(stream);
 331                                         goto error_unlock;
 332                                 }
 333
 334                                 if (nb_created) {
 335                                         /* Update number of created stream counter. */
 336                                         (*nb_created)++;
 337                                 }
 338                                 /*
 339                                  * Ensure a self-reference is preserved even
 340                                  * after we have put our local reference.
 341                                  */
 342                                 if (!viewer_stream_get(vstream)) {
 343                                         ERR("Unable to get self-reference on viewer stream, logic error.");
 344                                         abort();
 345                                 }
 346                         } else {
 347                                 if (!vstream->sent_flag && nb_unsent) {
 348                                         /* Update number of unsent stream counter. */
 349                                         (*nb_unsent)++;
 350                                 }
 351                         }
 352                         /* Update number of total stream counter. */
 353                         if (nb_total) {
 354                                 if (stream->is_metadata) {
 355                                         if (!stream->closed ||
 356                                                         stream->metadata_received > vstream->metadata_sent) {
 357                                                 (*nb_total)++;
 358                                         }
 359                                 } else {
 360                                         if (!stream->closed ||
 361                                                 !(((int64_t) (stream->prev_seq - stream->last_net_seq_num)) >= 0)) {
 362
 363                                                 (*nb_total)++;
 364                                         }
 365                                 }
 366                         }
 367                         /* Put local reference. */
 368                         viewer_stream_put(vstream);
 369                 next:
 370                         stream_put(stream);
 371                 }
 372                 ctf_trace_put(ctf_trace);
 373         }
 374
 375         ret = 0;
 376
 377 error_unlock:
 378         rcu_read_unlock();
 379         pthread_mutex_unlock(&session->lock);
 380         return ret;
 381 }
 382
 383 int relayd_live_stop(void)
 384 {
 385         /* Stop dispatch thread */
 386         CMM_STORE_SHARED(live_dispatch_thread_exit, 1);
 387         futex_nto1_wake(&viewer_conn_queue.futex);
 388         return 0;
 389 }
 390
 391 /*
 392  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
 393  */
 394 static
 395 int create_thread_poll_set(struct lttng_poll_event *events, int size)
 396 {
 397         int ret;
 398
 399         if (events == NULL || size == 0) {
 400                 ret = -1;
 401                 goto error;
 402         }
 403
 404         ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
 405         if (ret < 0) {
 406                 goto error;
 407         }
 408
 409         /* Add quit pipe */
 410         ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN | LPOLLERR);
 411         if (ret < 0) {
 412                 goto error;
 413         }
 414
 415         return 0;
 416
 417 error:
 418         return ret;
 419 }
 420
 421 /*
 422  * Check if the thread quit pipe was triggered.
 423  *
 424  * Return 1 if it was triggered else 0;
 425  */
 426 static
 427 int check_thread_quit_pipe(int fd, uint32_t events)
 428 {
 429         if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
 430                 return 1;
 431         }
 432
 433         return 0;
 434 }
 435
 436 /*
 437  * Create and init socket from uri.
 438  */
 439 static
 440 struct lttcomm_sock *init_socket(struct lttng_uri *uri)
 441 {
 442         int ret;
 443         struct lttcomm_sock *sock = NULL;
 444
 445         sock = lttcomm_alloc_sock_from_uri(uri);
 446         if (sock == NULL) {
 447                 ERR("Allocating socket");
 448                 goto error;
 449         }
 450
 451         ret = lttcomm_create_sock(sock);
 452         if (ret < 0) {
 453                 goto error;
 454         }
 455         DBG("Listening on sock %d for live", sock->fd);
 456
 457         ret = sock->ops->bind(sock);
 458         if (ret < 0) {
 459                 goto error;
 460         }
 461
 462         ret = sock->ops->listen(sock, -1);
 463         if (ret < 0) {
 464                 goto error;
 465
 466         }
 467
 468         return sock;
 469
 470 error:
 471         if (sock) {
 472                 lttcomm_destroy_sock(sock);
 473         }
 474         return NULL;
 475 }
 476
 477 /*
 478  * This thread manages the listening for new connections on the network
 479  */
 480 static
 481 void *thread_listener(void *data)
 482 {
 483         int i, ret, pollfd, err = -1;
 484         uint32_t revents, nb_fd;
 485         struct lttng_poll_event events;
 486         struct lttcomm_sock *live_control_sock;
 487
 488         DBG("[thread] Relay live listener started");
 489
 490         health_register(health_relayd, HEALTH_RELAYD_TYPE_LIVE_LISTENER);
 491
 492         health_code_update();
 493
 494         live_control_sock = init_socket(live_uri);
 495         if (!live_control_sock) {
 496                 goto error_sock_control;
 497         }
 498
 499         /* Pass 2 as size here for the thread quit pipe and control sockets. */
 500         ret = create_thread_poll_set(&events, 2);
 501         if (ret < 0) {
 502                 goto error_create_poll;
 503         }
 504
 505         /* Add the control socket */
 506         ret = lttng_poll_add(&events, live_control_sock->fd, LPOLLIN | LPOLLRDHUP);
 507         if (ret < 0) {
 508                 goto error_poll_add;
 509         }
 510
 511         lttng_relay_notify_ready();
 512
 513         if (testpoint(relayd_thread_live_listener)) {
 514                 goto error_testpoint;
 515         }
 516
 517         while (1) {
 518                 health_code_update();
 519
 520                 DBG("Listener accepting live viewers connections");
 521
 522 restart:
 523                 health_poll_entry();
 524                 ret = lttng_poll_wait(&events, -1);
 525                 health_poll_exit();
 526                 if (ret < 0) {
 527                         /*
 528                          * Restart interrupted system call.
 529                          */
 530                         if (errno == EINTR) {
 531                                 goto restart;
 532                         }
 533                         goto error;
 534                 }
 535                 nb_fd = ret;
 536
 537                 DBG("Relay new viewer connection received");
 538                 for (i = 0; i < nb_fd; i++) {
 539                         health_code_update();
 540
 541                         /* Fetch once the poll data */
 542                         revents = LTTNG_POLL_GETEV(&events, i);
 543                         pollfd = LTTNG_POLL_GETFD(&events, i);
 544
 545                         if (!revents) {
 546                                 /* No activity for this FD (poll implementation). */
 547                                 continue;
 548                         }
 549
 550                         /* Thread quit pipe has been closed. Killing thread. */
 551                         ret = check_thread_quit_pipe(pollfd, revents);
 552                         if (ret) {
 553                                 err = 0;
 554                                 goto exit;
 555                         }
 556
 557                         if (revents & LPOLLIN) {
 558                                 /*
 559                                  * A new connection is requested, therefore a
 560                                  * viewer connection is allocated in this
 561                                  * thread, enqueued to a global queue and
 562                                  * dequeued (and freed) in the worker thread.
 563                                  */
 564                                 int val = 1;
 565                                 struct relay_connection *new_conn;
 566                                 struct lttcomm_sock *newsock;
 567
 568                                 newsock = live_control_sock->ops->accept(live_control_sock);
 569                                 if (!newsock) {
 570                                         PERROR("accepting control sock");
 571                                         goto error;
 572                                 }
 573                                 DBG("Relay viewer connection accepted socket %d", newsock->fd);
 574
 575                                 ret = setsockopt(newsock->fd, SOL_SOCKET, SO_REUSEADDR, &val,
 576                                                 sizeof(val));
 577                                 if (ret < 0) {
 578                                         PERROR("setsockopt inet");
 579                                         lttcomm_destroy_sock(newsock);
 580                                         goto error;
 581                                 }
 582                                 new_conn = connection_create(newsock, RELAY_CONNECTION_UNKNOWN);
 583                                 if (!new_conn) {
 584                                         lttcomm_destroy_sock(newsock);
 585                                         goto error;
 586                                 }
 587                                 /* Ownership assumed by the connection. */
 588                                 newsock = NULL;
 589
 590                                 /* Enqueue request for the dispatcher thread. */
 591                                 cds_wfcq_enqueue(&viewer_conn_queue.head, &viewer_conn_queue.tail,
 592                                                  &new_conn->qnode);
 593
 594                                 /*
 595                                  * Wake the dispatch queue futex.
 596                                  * Implicit memory barrier with the
 597                                  * exchange in cds_wfcq_enqueue.
 598                                  */
 599                                 futex_nto1_wake(&viewer_conn_queue.futex);
 600                         } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 601                                 ERR("socket poll error");
 602                                 goto error;
 603                         } else {
 604                                 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
 605                                 goto error;
 606                         }
 607                 }
 608         }
 609
 610 exit:
 611 error:
 612 error_poll_add:
 613 error_testpoint:
 614         lttng_poll_clean(&events);
 615 error_create_poll:
 616         if (live_control_sock->fd >= 0) {
 617                 ret = live_control_sock->ops->close(live_control_sock);
 618                 if (ret) {
 619                         PERROR("close");
 620                 }
 621         }
 622         lttcomm_destroy_sock(live_control_sock);
 623 error_sock_control:
 624         if (err) {
 625                 health_error();
 626                 DBG("Live viewer listener thread exited with error");
 627         }
 628         health_unregister(health_relayd);
 629         DBG("Live viewer listener thread cleanup complete");
 630         if (lttng_relay_stop_threads()) {
 631                 ERR("Error stopping threads");
 632         }
 633         return NULL;
 634 }
 635
 636 /*
 637  * This thread manages the dispatching of the requests to worker threads
 638  */
 639 static
 640 void *thread_dispatcher(void *data)
 641 {
 642         int err = -1;
 643         ssize_t ret;
 644         struct cds_wfcq_node *node;
 645         struct relay_connection *conn = NULL;
 646
 647         DBG("[thread] Live viewer relay dispatcher started");
 648
 649         health_register(health_relayd, HEALTH_RELAYD_TYPE_LIVE_DISPATCHER);
 650
 651         if (testpoint(relayd_thread_live_dispatcher)) {
 652                 goto error_testpoint;
 653         }
 654
 655         health_code_update();
 656
 657         while (!CMM_LOAD_SHARED(live_dispatch_thread_exit)) {
 658                 health_code_update();
 659
 660                 /* Atomically prepare the queue futex */
 661                 futex_nto1_prepare(&viewer_conn_queue.futex);
 662
 663                 do {
 664                         health_code_update();
 665
 666                         /* Dequeue commands */
 667                         node = cds_wfcq_dequeue_blocking(&viewer_conn_queue.head,
 668                                                          &viewer_conn_queue.tail);
 669                         if (node == NULL) {
 670                                 DBG("Woken up but nothing in the live-viewer "
 671                                                 "relay command queue");
 672                                 /* Continue thread execution */
 673                                 break;
 674                         }
 675                         conn = caa_container_of(node, struct relay_connection, qnode);
 676                         DBG("Dispatching viewer request waiting on sock %d",
 677                                         conn->sock->fd);
 678
 679                         /*
 680                          * Inform worker thread of the new request. This
 681                          * call is blocking so we can be assured that
 682                          * the data will be read at some point in time
 683                          * or wait to the end of the world :)
 684                          */
 685                         ret = lttng_write(live_conn_pipe[1], &conn, sizeof(conn));
 686                         if (ret < 0) {
 687                                 PERROR("write conn pipe");
 688                                 connection_put(conn);
 689                                 goto error;
 690                         }
 691                 } while (node != NULL);
 692
 693                 /* Futex wait on queue. Blocking call on futex() */
 694                 health_poll_entry();
 695                 futex_nto1_wait(&viewer_conn_queue.futex);
 696                 health_poll_exit();
 697         }
 698
 699         /* Normal exit, no error */
 700         err = 0;
 701
 702 error:
 703 error_testpoint:
 704         if (err) {
 705                 health_error();
 706                 ERR("Health error occurred in %s", __func__);
 707         }
 708         health_unregister(health_relayd);
 709         DBG("Live viewer dispatch thread dying");
 710         if (lttng_relay_stop_threads()) {
 711                 ERR("Error stopping threads");
 712         }
 713         return NULL;
 714 }
 715
 716 /*
 717  * Establish connection with the viewer and check the versions.
 718  *
 719  * Return 0 on success or else negative value.
 720  */
 721 static
 722 int viewer_connect(struct relay_connection *conn)
 723 {
 724         int ret;
 725         struct lttng_viewer_connect reply, msg;
 726
 727         conn->version_check_done = 1;
 728
 729         health_code_update();
 730
 731         DBG("Viewer is establishing a connection to the relayd.");
 732
 733         ret = recv_request(conn->sock, &msg, sizeof(msg));
 734         if (ret < 0) {
 735                 goto end;
 736         }
 737
 738         health_code_update();
 739
 740         memset(&reply, 0, sizeof(reply));
 741         reply.major = RELAYD_VERSION_COMM_MAJOR;
 742         reply.minor = RELAYD_VERSION_COMM_MINOR;
 743
 744         /* Major versions must be the same */
 745         if (reply.major != be32toh(msg.major)) {
 746                 DBG("Incompatible major versions ([relayd] %u vs [client] %u)",
 747                                 reply.major, be32toh(msg.major));
 748                 ret = -1;
 749                 goto end;
 750         }
 751
 752         conn->major = reply.major;
 753         /* We adapt to the lowest compatible version */
 754         if (reply.minor <= be32toh(msg.minor)) {
 755                 conn->minor = reply.minor;
 756         } else {
 757                 conn->minor = be32toh(msg.minor);
 758         }
 759
 760         if (be32toh(msg.type) == LTTNG_VIEWER_CLIENT_COMMAND) {
 761                 conn->type = RELAY_VIEWER_COMMAND;
 762         } else if (be32toh(msg.type) == LTTNG_VIEWER_CLIENT_NOTIFICATION) {
 763                 conn->type = RELAY_VIEWER_NOTIFICATION;
 764         } else {
 765                 ERR("Unknown connection type : %u", be32toh(msg.type));
 766                 ret = -1;
 767                 goto end;
 768         }
 769
 770         reply.major = htobe32(reply.major);
 771         reply.minor = htobe32(reply.minor);
 772         if (conn->type == RELAY_VIEWER_COMMAND) {
 773                 /*
 774                  * Increment outside of htobe64 macro, because the argument can
 775                  * be used more than once within the macro, and thus the
 776                  * operation may be undefined.
 777                  */
 778                 pthread_mutex_lock(&last_relay_viewer_session_id_lock);
 779                 last_relay_viewer_session_id++;
 780                 pthread_mutex_unlock(&last_relay_viewer_session_id_lock);
 781                 reply.viewer_session_id = htobe64(last_relay_viewer_session_id);
 782         }
 783
 784         health_code_update();
 785
 786         ret = send_response(conn->sock, &reply, sizeof(reply));
 787         if (ret < 0) {
 788                 goto end;
 789         }
 790
 791         health_code_update();
 792
 793         DBG("Version check done using protocol %u.%u", conn->major, conn->minor);
 794         ret = 0;
 795
 796 end:
 797         return ret;
 798 }
 799
 800 /*
 801  * Send the viewer the list of current sessions.
 802  * We need to create a copy of the hash table content because otherwise
 803  * we cannot assume the number of entries stays the same between getting
 804  * the number of HT elements and iteration over the HT.
 805  *
 806  * Return 0 on success or else a negative value.
 807  */
 808 static
 809 int viewer_list_sessions(struct relay_connection *conn)
 810 {
 811         int ret = 0;
 812         struct lttng_viewer_list_sessions session_list;
 813         struct lttng_ht_iter iter;
 814         struct relay_session *session;
 815         struct lttng_viewer_session *send_session_buf = NULL;
 816         uint32_t buf_count = SESSION_BUF_DEFAULT_COUNT;
 817         uint32_t count = 0;
 818
 819         DBG("List sessions received");
 820
 821         send_session_buf = zmalloc(SESSION_BUF_DEFAULT_COUNT * sizeof(*send_session_buf));
 822         if (!send_session_buf) {
 823                 return -1;
 824         }
 825
 826         rcu_read_lock();
 827         cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
 828                         session_n.node) {
 829                 struct lttng_viewer_session *send_session;
 830
 831                 health_code_update();
 832
 833                 if (count >= buf_count) {
 834                         struct lttng_viewer_session *newbuf;
 835                         uint32_t new_buf_count = buf_count << 1;
 836
 837                         newbuf = realloc(send_session_buf,
 838                                 new_buf_count * sizeof(*send_session_buf));
 839                         if (!newbuf) {
 840                                 ret = -1;
 841                                 break;
 842                         }
 843                         send_session_buf = newbuf;
 844                         buf_count = new_buf_count;
 845                 }
 846                 send_session = &send_session_buf[count];
 847                 if (lttng_strncpy(send_session->session_name,
 848                                 session->session_name,
 849                                 sizeof(send_session->session_name))) {
 850                         ret = -1;
 851                         break;
 852                 }
 853                 if (lttng_strncpy(send_session->hostname, session->hostname,
 854                                 sizeof(send_session->hostname))) {
 855                         ret = -1;
 856                         break;
 857                 }
 858                 send_session->id = htobe64(session->id);
 859                 send_session->live_timer = htobe32(session->live_timer);
 860                 if (session->viewer_attached) {
 861                         send_session->clients = htobe32(1);
 862                 } else {
 863                         send_session->clients = htobe32(0);
 864                 }
 865                 send_session->streams = htobe32(session->stream_count);
 866                 count++;
 867         }
 868         rcu_read_unlock();
 869         if (ret < 0) {
 870                 goto end_free;
 871         }
 872
 873         session_list.sessions_count = htobe32(count);
 874
 875         health_code_update();
 876
 877         ret = send_response(conn->sock, &session_list, sizeof(session_list));
 878         if (ret < 0) {
 879                 goto end_free;
 880         }
 881
 882         health_code_update();
 883
 884         ret = send_response(conn->sock, send_session_buf,
 885                         count * sizeof(*send_session_buf));
 886         if (ret < 0) {
 887                 goto end_free;
 888         }
 889         health_code_update();
 890
 891         ret = 0;
 892 end_free:
 893         free(send_session_buf);
 894         return ret;
 895 }
 896
 897 /*
 898  * Send the viewer the list of current streams.
 899  */
 900 static
 901 int viewer_get_new_streams(struct relay_connection *conn)
 902 {
 903         int ret, send_streams = 0;
 904         uint32_t nb_created = 0, nb_unsent = 0, nb_streams = 0, nb_total = 0;
 905         struct lttng_viewer_new_streams_request request;
 906         struct lttng_viewer_new_streams_response response;
 907         struct relay_session *session;
 908         uint64_t session_id;
 909         bool closed = false;
 910
 911         assert(conn);
 912
 913         DBG("Get new streams received");
 914
 915         health_code_update();
 916
 917         /* Receive the request from the connected client. */
 918         ret = recv_request(conn->sock, &request, sizeof(request));
 919         if (ret < 0) {
 920                 goto error;
 921         }
 922         session_id = be64toh(request.session_id);
 923
 924         health_code_update();
 925
 926         memset(&response, 0, sizeof(response));
 927
 928         session = session_get_by_id(session_id);
 929         if (!session) {
 930                 DBG("Relay session %" PRIu64 " not found", session_id);
 931                 response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR);
 932                 goto send_reply;
 933         }
 934
 935         if (!viewer_session_is_attached(conn->viewer_session, session)) {
 936                 send_streams = 0;
 937                 response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR);
 938                 goto send_reply;
 939         }
 940
 941         send_streams = 1;
 942         response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_OK);
 943
 944         ret = make_viewer_streams(session, LTTNG_VIEWER_SEEK_LAST, &nb_total, &nb_unsent,
 945                         &nb_created, &closed);
 946         if (ret < 0) {
 947                 goto end_put_session;
 948         }
 949         /* Only send back the newly created streams with the unsent ones. */
 950         nb_streams = nb_created + nb_unsent;
 951         response.streams_count = htobe32(nb_streams);
 952
 953         /*
 954          * If the session is closed, HUP when there are no more streams
 955          * with data.
 956          */
 957         if (closed && nb_total == 0) {
 958                 send_streams = 0;
 959                 response.streams_count = 0;
 960                 response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_HUP);
 961                 goto send_reply;
 962         }
 963
 964 send_reply:
 965         health_code_update();
 966         ret = send_response(conn->sock, &response, sizeof(response));
 967         if (ret < 0) {
 968                 goto end_put_session;
 969         }
 970         health_code_update();
 971
 972         /*
 973          * Unknown or empty session, just return gracefully, the viewer
 974          * knows what is happening.
 975          */
 976         if (!send_streams || !nb_streams) {
 977                 ret = 0;
 978                 goto end_put_session;
 979         }
 980
 981         /*
 982          * Send stream and *DON'T* ignore the sent flag so every viewer
 983          * streams that were not sent from that point will be sent to
 984          * the viewer.
 985          */
 986         ret = send_viewer_streams(conn->sock, session, 0);
 987         if (ret < 0) {
 988                 goto end_put_session;
 989         }
 990
 991 end_put_session:
 992         if (session) {
 993                 session_put(session);
 994         }
 995 error:
 996         return ret;
 997 }
 998
 999 /*
1000  * Send the viewer the list of current sessions.
1001  */
1002 static
1003 int viewer_attach_session(struct relay_connection *conn)
1004 {
1005         int send_streams = 0;
1006         ssize_t ret;
1007         uint32_t nb_streams = 0;
1008         enum lttng_viewer_seek seek_type;
1009         struct lttng_viewer_attach_session_request request;
1010         struct lttng_viewer_attach_session_response response;
1011         struct relay_session *session = NULL;
1012         bool closed = false;
1013
1014         assert(conn);
1015
1016         health_code_update();
1017
1018         /* Receive the request from the connected client. */
1019         ret = recv_request(conn->sock, &request, sizeof(request));
1020         if (ret < 0) {
1021                 goto error;
1022         }
1023
1024         health_code_update();
1025
1026         memset(&response, 0, sizeof(response));
1027
1028         if (!conn->viewer_session) {
1029                 DBG("Client trying to attach before creating a live viewer session");
1030                 response.status = htobe32(LTTNG_VIEWER_ATTACH_NO_SESSION);
1031                 goto send_reply;
1032         }
1033
1034         session = session_get_by_id(be64toh(request.session_id));
1035         if (!session) {
1036                 DBG("Relay session %" PRIu64 " not found",
1037                                 be64toh(request.session_id));
1038                 response.status = htobe32(LTTNG_VIEWER_ATTACH_UNK);
1039                 goto send_reply;
1040         }
1041         DBG("Attach session ID %" PRIu64 " received",
1042                 be64toh(request.session_id));
1043
1044         if (session->live_timer == 0) {
1045                 DBG("Not live session");
1046                 response.status = htobe32(LTTNG_VIEWER_ATTACH_NOT_LIVE);
1047                 goto send_reply;
1048         }
1049
1050         send_streams = 1;
1051         ret = viewer_session_attach(conn->viewer_session, session);
1052         if (ret) {
1053                 DBG("Already a viewer attached");
1054                 response.status = htobe32(LTTNG_VIEWER_ATTACH_ALREADY);
1055                 goto send_reply;
1056         }
1057
1058         switch (be32toh(request.seek)) {
1059         case LTTNG_VIEWER_SEEK_BEGINNING:
1060         case LTTNG_VIEWER_SEEK_LAST:
1061                 response.status = htobe32(LTTNG_VIEWER_ATTACH_OK);
1062                 seek_type = be32toh(request.seek);
1063                 break;
1064         default:
1065                 ERR("Wrong seek parameter");
1066                 response.status = htobe32(LTTNG_VIEWER_ATTACH_SEEK_ERR);
1067                 send_streams = 0;
1068                 goto send_reply;
1069         }
1070
1071         ret = make_viewer_streams(session, seek_type, &nb_streams, NULL,
1072                         NULL, &closed);
1073         if (ret < 0) {
1074                 goto end_put_session;
1075         }
1076         response.streams_count = htobe32(nb_streams);
1077
1078         /*
1079          * If the session is closed when the viewer is attaching, it
1080          * means some of the streams may have been concurrently removed,
1081          * so we don't allow the viewer to attach, even if there are
1082          * streams available.
1083          */
1084         if (closed) {
1085                 send_streams = 0;
1086                 response.streams_count = 0;
1087                 response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_HUP);
1088                 goto send_reply;
1089         }
1090
1091 send_reply:
1092         health_code_update();
1093         ret = send_response(conn->sock, &response, sizeof(response));
1094         if (ret < 0) {
1095                 goto end_put_session;
1096         }
1097         health_code_update();
1098
1099         /*
1100          * Unknown or empty session, just return gracefully, the viewer
1101          * knows what is happening.
1102          */
1103         if (!send_streams || !nb_streams) {
1104                 ret = 0;
1105                 goto end_put_session;
1106         }
1107
1108         /* Send stream and ignore the sent flag. */
1109         ret = send_viewer_streams(conn->sock, session, 1);
1110         if (ret < 0) {
1111                 goto end_put_session;
1112         }
1113
1114 end_put_session:
1115         if (session) {
1116                 session_put(session);
1117         }
1118 error:
1119         return ret;
1120 }
1121
1122 /*
1123  * Open the index file if needed for the given vstream.
1124  *
1125  * If an index file is successfully opened, the vstream index_fd set with
1126  * it.
1127  *
1128  * Return 0 on success, a negative value on error (-ENOENT if not ready yet).
1129  *
1130  * Called with rstream lock held.
1131  */
1132 static int try_open_index(struct relay_viewer_stream *vstream,
1133                 struct relay_stream *rstream)
1134 {
1135         int ret = 0;
1136
1137         if (vstream->index_fd) {
1138                 goto end;
1139         }
1140
1141         /*
1142          * First time, we open the index file and at least one index is ready.
1143          */
1144         if (rstream->index_received_seqcount == 0) {
1145                 ret = -ENOENT;
1146                 goto end;
1147         }
1148         ret = index_open(vstream->path_name, vstream->channel_name,
1149                         vstream->stream->tracefile_count,
1150                         vstream->current_tracefile_id);
1151         if (ret >= 0) {
1152                 vstream->index_fd = stream_fd_create(ret);
1153                 if (!vstream->index_fd) {
1154                         if (close(ret)) {
1155                                 PERROR("close");
1156                         }
1157                         ret = -1;
1158                 } else {
1159                         ret = 0;
1160                 }
1161                 goto end;
1162         }
1163
1164 end:
1165         return ret;
1166 }
1167
1168 /*
1169  * Check the status of the index for the given stream. This function
1170  * updates the index structure if needed and can put (close) the vstream
1171  * in the HUP situation.
1172  *
1173  * Return 0 means that we can proceed with the index. A value of 1 means
1174  * that the index has been updated and is ready to be sent to the
1175  * client. A negative value indicates an error that can't be handled.
1176  *
1177  * Called with rstream lock held.
1178  */
1179 static int check_index_status(struct relay_viewer_stream *vstream,
1180                 struct relay_stream *rstream, struct ctf_trace *trace,
1181                 struct lttng_viewer_index *index)
1182 {
1183         int ret;
1184
1185         if (trace->session->connection_closed
1186                         && rstream->index_received_seqcount
1187                                 == vstream->index_sent_seqcount) {
1188                 /* Last index sent and session connection is closed. */
1189                 index->status = htobe32(LTTNG_VIEWER_INDEX_HUP);
1190                 goto hup;
1191         } else if (rstream->beacon_ts_end != -1ULL &&
1192                         rstream->index_received_seqcount
1193                                 == vstream->index_sent_seqcount) {
1194                 /*
1195                  * We've received a synchronization beacon and the last index
1196                  * available has been sent, the index for now is inactive.
1197                  *
1198                  * In this case, we have received a beacon which allows us to
1199                  * inform the client of a time interval during which we can
1200                  * guarantee that there are no events to read (and never will
1201                  * be).
1202                  */
1203                 index->status = htobe32(LTTNG_VIEWER_INDEX_INACTIVE);
1204                 index->timestamp_end = htobe64(rstream->beacon_ts_end);
1205                 index->stream_id = htobe64(rstream->ctf_stream_id);
1206                 goto index_ready;
1207         } else if (rstream->index_received_seqcount
1208                         == vstream->index_sent_seqcount) {
1209                 /*
1210                  * This checks whether received == sent seqcount. In
1211                  * this case, we have not received a beacon. Therefore,
1212                  * we can only ask the client to retry later.
1213                  */
1214                 index->status = htobe32(LTTNG_VIEWER_INDEX_RETRY);
1215                 goto index_ready;
1216         } else if (!tracefile_array_seq_in_file(rstream->tfa,
1217                         vstream->current_tracefile_id,
1218                         vstream->index_sent_seqcount)) {
1219                 /*
1220                  * The next index we want to send cannot be read either
1221                  * because we need to perform a rotation, or due to
1222                  * the producer having overwritten its trace file.
1223                  */
1224                 DBG("Viewer stream %" PRIu64 " rotation",
1225                                 vstream->stream->stream_handle);
1226                 ret = viewer_stream_rotate(vstream);
1227                 if (ret < 0) {
1228                         goto end;
1229                 } else if (ret == 1) {
1230                         /* EOF across entire stream. */
1231                         index->status = htobe32(LTTNG_VIEWER_INDEX_HUP);
1232                         goto hup;
1233                 }
1234                 /*
1235                  * If we have been pushed due to overwrite, it
1236                  * necessarily means there is data that can be read in
1237                  * the stream. If we rotated because we reached the end
1238                  * of a tracefile, it means the following tracefile
1239                  * needs to contain at least one index, else we would
1240                  * have already returned LTTNG_VIEWER_INDEX_RETRY to the
1241                  * viewer. The updated index_sent_seqcount needs to
1242                  * point to a readable index entry now.
1243                  *
1244                  * In the case where we "rotate" on a single file, we
1245                  * can end up in a case where the requested index is
1246                  * still unavailable.
1247                  */
1248                 if (rstream->tracefile_count == 1 &&
1249                                 !tracefile_array_seq_in_file(
1250                                         rstream->tfa,
1251                                         vstream->current_tracefile_id,
1252                                         vstream->index_sent_seqcount)) {
1253                         index->status = htobe32(LTTNG_VIEWER_INDEX_RETRY);
1254                         goto index_ready;
1255                 }
1256                 assert(tracefile_array_seq_in_file(rstream->tfa,
1257                                 vstream->current_tracefile_id,
1258                                 vstream->index_sent_seqcount));
1259         }
1260         /* ret == 0 means successful so we continue. */
1261         ret = 0;
1262 end:
1263         return ret;
1264
1265 hup:
1266         viewer_stream_put(vstream);
1267 index_ready:
1268         return 1;
1269 }
1270
1271 /*
1272  * Send the next index for a stream.
1273  *
1274  * Return 0 on success or else a negative value.
1275  */
1276 static
1277 int viewer_get_next_index(struct relay_connection *conn)
1278 {
1279         int ret;
1280         ssize_t read_ret;
1281         struct lttng_viewer_get_next_index request_index;
1282         struct lttng_viewer_index viewer_index;
1283         struct ctf_packet_index packet_index;
1284         struct relay_viewer_stream *vstream = NULL;
1285         struct relay_stream *rstream = NULL;
1286         struct ctf_trace *ctf_trace = NULL;
1287         struct relay_viewer_stream *metadata_viewer_stream = NULL;
1288
1289         assert(conn);
1290
1291         DBG("Viewer get next index");
1292
1293         memset(&viewer_index, 0, sizeof(viewer_index));
1294         health_code_update();
1295
1296         ret = recv_request(conn->sock, &request_index, sizeof(request_index));
1297         if (ret < 0) {
1298                 goto end;
1299         }
1300         health_code_update();
1301
1302         vstream = viewer_stream_get_by_id(be64toh(request_index.stream_id));
1303         if (!vstream) {
1304                 DBG("Client requested index of unknown stream id %" PRIu64,
1305                                 be64toh(request_index.stream_id));
1306                 viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_ERR);
1307                 goto send_reply;
1308         }
1309
1310         /* Use back. ref. Protected by refcounts. */
1311         rstream = vstream->stream;
1312         ctf_trace = rstream->trace;
1313
1314         /* metadata_viewer_stream may be NULL. */
1315         metadata_viewer_stream =
1316                         ctf_trace_get_viewer_metadata_stream(ctf_trace);
1317
1318         pthread_mutex_lock(&rstream->lock);
1319
1320         /*
1321          * The viewer should not ask for index on metadata stream.
1322          */
1323         if (rstream->is_metadata) {
1324                 viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_HUP);
1325                 goto send_reply;
1326         }
1327
1328         /* Try to open an index if one is needed for that stream. */
1329         ret = try_open_index(vstream, rstream);
1330         if (ret < 0) {
1331                 if (ret == -ENOENT) {
1332                         /*
1333                          * The index is created only when the first data
1334                          * packet arrives, it might not be ready at the
1335                          * beginning of the session
1336                          */
1337                         viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_RETRY);
1338                 } else {
1339                         /* Unhandled error. */
1340                         viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_ERR);
1341                 }
1342                 goto send_reply;
1343         }
1344
1345         ret = check_index_status(vstream, rstream, ctf_trace, &viewer_index);
1346         if (ret < 0) {
1347                 goto error_put;
1348         } else if (ret == 1) {
1349                 /*
1350                  * We have no index to send and check_index_status has populated
1351                  * viewer_index's status.
1352                  */
1353                 goto send_reply;
1354         }
1355         /* At this point, ret is 0 thus we will be able to read the index. */
1356         assert(!ret);
1357
1358         /*
1359          * vstream->stream_fd may be NULL if it has been closed by
1360          * tracefile rotation, or if we are at the beginning of the
1361          * stream. We open the data stream file here to protect against
1362          * overwrite caused by tracefile rotation (in association with
1363          * unlink performed before overwrite).
1364          */
1365         if (!vstream->stream_fd) {
1366                 char fullpath[PATH_MAX];
1367
1368                 if (vstream->stream->tracefile_count > 0) {
1369                         ret = snprintf(fullpath, PATH_MAX, "%s/%s_%" PRIu64,
1370                                         vstream->path_name,
1371                                         vstream->channel_name,
1372                                         vstream->current_tracefile_id);
1373                 } else {
1374                         ret = snprintf(fullpath, PATH_MAX, "%s/%s",
1375                                         vstream->path_name,
1376                                         vstream->channel_name);
1377                 }
1378                 if (ret < 0) {
1379                         goto error_put;
1380                 }
1381                 ret = open(fullpath, O_RDONLY);
1382                 if (ret < 0) {
1383                         PERROR("Relay opening trace file");
1384                         goto error_put;
1385                 }
1386                 vstream->stream_fd = stream_fd_create(ret);
1387                 if (!vstream->stream_fd) {
1388                         if (close(ret)) {
1389                                 PERROR("close");
1390                         }
1391                         goto error_put;
1392                 }
1393         }
1394
1395         ret = check_new_streams(conn);
1396         if (ret < 0) {
1397                 viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_ERR);
1398                 goto send_reply;
1399         } else if (ret == 1) {
1400                 viewer_index.flags |= LTTNG_VIEWER_FLAG_NEW_STREAM;
1401         }
1402
1403         read_ret = lttng_read(vstream->index_fd->fd, &packet_index,
1404                         sizeof(packet_index));
1405         if (read_ret < sizeof(packet_index)) {
1406                 ERR("Relay reading index file %d returned %zd",
1407                         vstream->index_fd->fd, read_ret);
1408                 viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_ERR);
1409                 goto send_reply;
1410         } else {
1411                 viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_OK);
1412                 vstream->index_sent_seqcount++;
1413         }
1414
1415         /*
1416          * Indexes are stored in big endian, no need to switch before sending.
1417          */
1418         DBG("Sending viewer index for stream %" PRIu64 " offset %" PRIu64,
1419                 rstream->stream_handle,
1420                 be64toh(packet_index.offset));
1421         viewer_index.offset = packet_index.offset;
1422         viewer_index.packet_size = packet_index.packet_size;
1423         viewer_index.content_size = packet_index.content_size;
1424         viewer_index.timestamp_begin = packet_index.timestamp_begin;
1425         viewer_index.timestamp_end = packet_index.timestamp_end;
1426         viewer_index.events_discarded = packet_index.events_discarded;
1427         viewer_index.stream_id = packet_index.stream_id;
1428
1429 send_reply:
1430         if (rstream) {
1431                 pthread_mutex_unlock(&rstream->lock);
1432         }
1433
1434         if (metadata_viewer_stream) {
1435                 pthread_mutex_lock(&metadata_viewer_stream->stream->lock);
1436                 DBG("get next index metadata check: recv %" PRIu64
1437                                 " sent %" PRIu64,
1438                         metadata_viewer_stream->stream->metadata_received,
1439                         metadata_viewer_stream->metadata_sent);
1440                 if (!metadata_viewer_stream->stream->metadata_received ||
1441                                 metadata_viewer_stream->stream->metadata_received >
1442                                         metadata_viewer_stream->metadata_sent) {
1443                         viewer_index.flags |= LTTNG_VIEWER_FLAG_NEW_METADATA;
1444                 }
1445                 pthread_mutex_unlock(&metadata_viewer_stream->stream->lock);
1446         }
1447
1448         viewer_index.flags = htobe32(viewer_index.flags);
1449         health_code_update();
1450
1451         ret = send_response(conn->sock, &viewer_index, sizeof(viewer_index));
1452         if (ret < 0) {
1453                 goto end;
1454         }
1455         health_code_update();
1456
1457         if (vstream) {
1458                 DBG("Index %" PRIu64 " for stream %" PRIu64 " sent",
1459                                 vstream->index_sent_seqcount,
1460                                 vstream->stream->stream_handle);
1461         }
1462 end:
1463         if (metadata_viewer_stream) {
1464                 viewer_stream_put(metadata_viewer_stream);
1465         }
1466         if (vstream) {
1467                 viewer_stream_put(vstream);
1468         }
1469         return ret;
1470
1471 error_put:
1472         pthread_mutex_unlock(&rstream->lock);
1473         if (metadata_viewer_stream) {
1474                 viewer_stream_put(metadata_viewer_stream);
1475         }
1476         viewer_stream_put(vstream);
1477         return ret;
1478 }
1479
1480 /*
1481  * Send the next index for a stream
1482  *
1483  * Return 0 on success or else a negative value.
1484  */
1485 static
1486 int viewer_get_packet(struct relay_connection *conn)
1487 {
1488         int ret, send_data = 0;
1489         char *data = NULL;
1490         uint32_t len = 0;
1491         ssize_t read_len;
1492         struct lttng_viewer_get_packet get_packet_info;
1493         struct lttng_viewer_trace_packet reply;
1494         struct relay_viewer_stream *vstream = NULL;
1495
1496         DBG2("Relay get data packet");
1497
1498         health_code_update();
1499
1500         ret = recv_request(conn->sock, &get_packet_info,
1501                         sizeof(get_packet_info));
1502         if (ret < 0) {
1503                 goto end;
1504         }
1505         health_code_update();
1506
1507         /* From this point on, the error label can be reached. */
1508         memset(&reply, 0, sizeof(reply));
1509
1510         vstream = viewer_stream_get_by_id(be64toh(get_packet_info.stream_id));
1511         if (!vstream) {
1512                 DBG("Client requested packet of unknown stream id %" PRIu64,
1513                                 be64toh(get_packet_info.stream_id));
1514                 reply.status = htobe32(LTTNG_VIEWER_GET_PACKET_ERR);
1515                 goto send_reply_nolock;
1516         }
1517
1518         pthread_mutex_lock(&vstream->stream->lock);
1519
1520         len = be32toh(get_packet_info.len);
1521         data = zmalloc(len);
1522         if (!data) {
1523                 PERROR("relay data zmalloc");
1524                 goto error;
1525         }
1526
1527         ret = lseek(vstream->stream_fd->fd, be64toh(get_packet_info.offset),
1528                         SEEK_SET);
1529         if (ret < 0) {
1530                 PERROR("lseek fd %d to offset %" PRIu64, vstream->stream_fd->fd,
1531                         be64toh(get_packet_info.offset));
1532                 goto error;
1533         }
1534         read_len = lttng_read(vstream->stream_fd->fd, data, len);
1535         if (read_len < len) {
1536                 PERROR("Relay reading trace file, fd: %d, offset: %" PRIu64,
1537                                 vstream->stream_fd->fd,
1538                                 be64toh(get_packet_info.offset));
1539                 goto error;
1540         }
1541         reply.status = htobe32(LTTNG_VIEWER_GET_PACKET_OK);
1542         reply.len = htobe32(len);
1543         send_data = 1;
1544         goto send_reply;
1545
1546 error:
1547         reply.status = htobe32(LTTNG_VIEWER_GET_PACKET_ERR);
1548
1549 send_reply:
1550         if (vstream) {
1551                 pthread_mutex_unlock(&vstream->stream->lock);
1552         }
1553 send_reply_nolock:
1554         reply.flags = htobe32(reply.flags);
1555
1556         health_code_update();
1557
1558         ret = send_response(conn->sock, &reply, sizeof(reply));
1559         if (ret < 0) {
1560                 goto end_free;
1561         }
1562         health_code_update();
1563
1564         if (send_data) {
1565                 health_code_update();
1566                 ret = send_response(conn->sock, data, len);
1567                 if (ret < 0) {
1568                         goto end_free;
1569                 }
1570                 health_code_update();
1571         }
1572
1573         DBG("Sent %u bytes for stream %" PRIu64, len,
1574                         be64toh(get_packet_info.stream_id));
1575
1576 end_free:
1577         free(data);
1578 end:
1579         if (vstream) {
1580                 viewer_stream_put(vstream);
1581         }
1582         return ret;
1583 }
1584
1585 /*
1586  * Send the session's metadata
1587  *
1588  * Return 0 on success else a negative value.
1589  */
1590 static
1591 int viewer_get_metadata(struct relay_connection *conn)
1592 {
1593         int ret = 0;
1594         ssize_t read_len;
1595         uint64_t len = 0;
1596         char *data = NULL;
1597         struct lttng_viewer_get_metadata request;
1598         struct lttng_viewer_metadata_packet reply;
1599         struct relay_viewer_stream *vstream = NULL;
1600
1601         assert(conn);
1602
1603         DBG("Relay get metadata");
1604
1605         health_code_update();
1606
1607         ret = recv_request(conn->sock, &request, sizeof(request));
1608         if (ret < 0) {
1609                 goto end;
1610         }
1611         health_code_update();
1612
1613         memset(&reply, 0, sizeof(reply));
1614
1615         vstream = viewer_stream_get_by_id(be64toh(request.stream_id));
1616         if (!vstream) {
1617                 /*
1618                  * The metadata stream can be closed by a CLOSE command
1619                  * just before we attach. It can also be closed by
1620                  * per-pid tracing during tracing. Therefore, it is
1621                  * possible that we cannot find this viewer stream.
1622                  * Reply back to the client with an error if we cannot
1623                  * find it.
1624                  */
1625                 DBG("Client requested metadata of unknown stream id %" PRIu64,
1626                                 be64toh(request.stream_id));
1627                 reply.status = htobe32(LTTNG_VIEWER_METADATA_ERR);
1628                 goto send_reply;
1629         }
1630         pthread_mutex_lock(&vstream->stream->lock);
1631         if (!vstream->stream->is_metadata) {
1632                 ERR("Invalid metadata stream");
1633                 goto error;
1634         }
1635
1636         assert(vstream->metadata_sent <= vstream->stream->metadata_received);
1637
1638         len = vstream->stream->metadata_received - vstream->metadata_sent;
1639         if (len == 0) {
1640                 reply.status = htobe32(LTTNG_VIEWER_NO_NEW_METADATA);
1641                 goto send_reply;
1642         }
1643
1644         /* first time, we open the metadata file */
1645         if (!vstream->stream_fd) {
1646                 char fullpath[PATH_MAX];
1647
1648                 ret = snprintf(fullpath, PATH_MAX, "%s/%s", vstream->path_name,
1649                                 vstream->channel_name);
1650                 if (ret < 0) {
1651                         goto error;
1652                 }
1653                 ret = open(fullpath, O_RDONLY);
1654                 if (ret < 0) {
1655                         PERROR("Relay opening metadata file");
1656                         goto error;
1657                 }
1658                 vstream->stream_fd = stream_fd_create(ret);
1659                 if (!vstream->stream_fd) {
1660                         if (close(ret)) {
1661                                 PERROR("close");
1662                         }
1663                         goto error;
1664                 }
1665         }
1666
1667         reply.len = htobe64(len);
1668         data = zmalloc(len);
1669         if (!data) {
1670                 PERROR("viewer metadata zmalloc");
1671                 goto error;
1672         }
1673
1674         read_len = lttng_read(vstream->stream_fd->fd, data, len);
1675         if (read_len < len) {
1676                 PERROR("Relay reading metadata file");
1677                 goto error;
1678         }
1679         vstream->metadata_sent += read_len;
1680         if (vstream->metadata_sent == vstream->stream->metadata_received
1681                         && vstream->stream->closed) {
1682                 /* Release ownership for the viewer metadata stream. */
1683                 viewer_stream_put(vstream);
1684         }
1685
1686         reply.status = htobe32(LTTNG_VIEWER_METADATA_OK);
1687
1688         goto send_reply;
1689
1690 error:
1691         reply.status = htobe32(LTTNG_VIEWER_METADATA_ERR);
1692
1693 send_reply:
1694         health_code_update();
1695         if (vstream) {
1696                 pthread_mutex_unlock(&vstream->stream->lock);
1697         }
1698         ret = send_response(conn->sock, &reply, sizeof(reply));
1699         if (ret < 0) {
1700                 goto end_free;
1701         }
1702         health_code_update();
1703
1704         if (len > 0) {
1705                 ret = send_response(conn->sock, data, len);
1706                 if (ret < 0) {
1707                         goto end_free;
1708                 }
1709         }
1710
1711         DBG("Sent %" PRIu64 " bytes of metadata for stream %" PRIu64, len,
1712                         be64toh(request.stream_id));
1713
1714         DBG("Metadata sent");
1715
1716 end_free:
1717         free(data);
1718 end:
1719         if (vstream) {
1720                 viewer_stream_put(vstream);
1721         }
1722         return ret;
1723 }
1724
1725 /*
1726  * Create a viewer session.
1727  *
1728  * Return 0 on success or else a negative value.
1729  */
1730 static
1731 int viewer_create_session(struct relay_connection *conn)
1732 {
1733         int ret;
1734         struct lttng_viewer_create_session_response resp;
1735
1736         DBG("Viewer create session received");
1737
1738         memset(&resp, 0, sizeof(resp));
1739         resp.status = htobe32(LTTNG_VIEWER_CREATE_SESSION_OK);
1740         conn->viewer_session = viewer_session_create();
1741         if (!conn->viewer_session) {
1742                 ERR("Allocation viewer session");
1743                 resp.status = htobe32(LTTNG_VIEWER_CREATE_SESSION_ERR);
1744                 goto send_reply;
1745         }
1746
1747 send_reply:
1748         health_code_update();
1749         ret = send_response(conn->sock, &resp, sizeof(resp));
1750         if (ret < 0) {
1751                 goto end;
1752         }
1753         health_code_update();
1754         ret = 0;
1755
1756 end:
1757         return ret;
1758 }
1759
1760 /*
1761  * Detach a viewer session.
1762  *
1763  * Return 0 on success or else a negative value.
1764  */
1765 static
1766 int viewer_detach_session(struct relay_connection *conn)
1767 {
1768         int ret;
1769         struct lttng_viewer_detach_session_response response;
1770         struct lttng_viewer_detach_session_request request;
1771         struct relay_session *session = NULL;
1772         uint64_t viewer_session_to_close;
1773
1774         DBG("Viewer detach session received");
1775
1776         assert(conn);
1777
1778         health_code_update();
1779
1780         /* Receive the request from the connected client. */
1781         ret = recv_request(conn->sock, &request, sizeof(request));
1782         if (ret < 0) {
1783                 goto end;
1784         }
1785         viewer_session_to_close = be64toh(request.session_id);
1786
1787         if (!conn->viewer_session) {
1788                 DBG("Client trying to detach before creating a live viewer session");
1789                 response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR);
1790                 goto send_reply;
1791         }
1792
1793         health_code_update();
1794
1795         memset(&response, 0, sizeof(response));
1796         DBG("Detaching from session ID %" PRIu64, viewer_session_to_close);
1797
1798         session = session_get_by_id(be64toh(request.session_id));
1799         if (!session) {
1800                 DBG("Relay session %" PRIu64 " not found",
1801                                 be64toh(request.session_id));
1802                 response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_UNK);
1803                 goto send_reply;
1804         }
1805
1806         ret = viewer_session_is_attached(conn->viewer_session, session);
1807         if (ret != 1) {
1808                 DBG("Not attached to this session");
1809                 response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR);
1810                 goto send_reply_put;
1811         }
1812
1813         viewer_session_close_one_session(conn->viewer_session, session);
1814         response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_OK);
1815         DBG("Session %" PRIu64 " detached.", viewer_session_to_close);
1816
1817 send_reply_put:
1818         session_put(session);
1819
1820 send_reply:
1821         health_code_update();
1822         ret = send_response(conn->sock, &response, sizeof(response));
1823         if (ret < 0) {
1824                 goto end;
1825         }
1826         health_code_update();
1827         ret = 0;
1828
1829 end:
1830         return ret;
1831 }
1832
1833 /*
1834  * live_relay_unknown_command: send -1 if received unknown command
1835  */
1836 static
1837 void live_relay_unknown_command(struct relay_connection *conn)
1838 {
1839         struct lttcomm_relayd_generic_reply reply;
1840
1841         memset(&reply, 0, sizeof(reply));
1842         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1843         (void) send_response(conn->sock, &reply, sizeof(reply));
1844 }
1845
1846 /*
1847  * Process the commands received on the control socket
1848  */
1849 static
1850 int process_control(struct lttng_viewer_cmd *recv_hdr,
1851                 struct relay_connection *conn)
1852 {
1853         int ret = 0;
1854         uint32_t msg_value;
1855
1856         msg_value = be32toh(recv_hdr->cmd);
1857
1858         /*
1859          * Make sure we've done the version check before any command other then a
1860          * new client connection.
1861          */
1862         if (msg_value != LTTNG_VIEWER_CONNECT && !conn->version_check_done) {
1863                 ERR("Viewer conn value %" PRIu32 " before version check", msg_value);
1864                 ret = -1;
1865                 goto end;
1866         }
1867
1868         switch (msg_value) {
1869         case LTTNG_VIEWER_CONNECT:
1870                 ret = viewer_connect(conn);
1871                 break;
1872         case LTTNG_VIEWER_LIST_SESSIONS:
1873                 ret = viewer_list_sessions(conn);
1874                 break;
1875         case LTTNG_VIEWER_ATTACH_SESSION:
1876                 ret = viewer_attach_session(conn);
1877                 break;
1878         case LTTNG_VIEWER_GET_NEXT_INDEX:
1879                 ret = viewer_get_next_index(conn);
1880                 break;
1881         case LTTNG_VIEWER_GET_PACKET:
1882                 ret = viewer_get_packet(conn);
1883                 break;
1884         case LTTNG_VIEWER_GET_METADATA:
1885                 ret = viewer_get_metadata(conn);
1886                 break;
1887         case LTTNG_VIEWER_GET_NEW_STREAMS:
1888                 ret = viewer_get_new_streams(conn);
1889                 break;
1890         case LTTNG_VIEWER_CREATE_SESSION:
1891                 ret = viewer_create_session(conn);
1892                 break;
1893         case LTTNG_VIEWER_DETACH_SESSION:
1894                 ret = viewer_detach_session(conn);
1895                 break;
1896         default:
1897                 ERR("Received unknown viewer command (%u)",
1898                                 be32toh(recv_hdr->cmd));
1899                 live_relay_unknown_command(conn);
1900                 ret = -1;
1901                 goto end;
1902         }
1903
1904 end:
1905         return ret;
1906 }
1907
1908 static
1909 void cleanup_connection_pollfd(struct lttng_poll_event *events, int pollfd)
1910 {
1911         int ret;
1912
1913         (void) lttng_poll_del(events, pollfd);
1914
1915         ret = close(pollfd);
1916         if (ret < 0) {
1917                 ERR("Closing pollfd %d", pollfd);
1918         }
1919 }
1920
1921 /*
1922  * This thread does the actual work
1923  */
1924 static
1925 void *thread_worker(void *data)
1926 {
1927         int ret, err = -1;
1928         uint32_t nb_fd;
1929         struct lttng_poll_event events;
1930         struct lttng_ht *viewer_connections_ht;
1931         struct lttng_ht_iter iter;
1932         struct lttng_viewer_cmd recv_hdr;
1933         struct relay_connection *destroy_conn;
1934
1935         DBG("[thread] Live viewer relay worker started");
1936
1937         rcu_register_thread();
1938
1939         health_register(health_relayd, HEALTH_RELAYD_TYPE_LIVE_WORKER);
1940
1941         if (testpoint(relayd_thread_live_worker)) {
1942                 goto error_testpoint;
1943         }
1944
1945         /* table of connections indexed on socket */
1946         viewer_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1947         if (!viewer_connections_ht) {
1948                 goto viewer_connections_ht_error;
1949         }
1950
1951         ret = create_thread_poll_set(&events, 2);
1952         if (ret < 0) {
1953                 goto error_poll_create;
1954         }
1955
1956         ret = lttng_poll_add(&events, live_conn_pipe[0], LPOLLIN | LPOLLRDHUP);
1957         if (ret < 0) {
1958                 goto error;
1959         }
1960
1961 restart:
1962         while (1) {
1963                 int i;
1964
1965                 health_code_update();
1966
1967                 /* Infinite blocking call, waiting for transmission */
1968                 DBG3("Relayd live viewer worker thread polling...");
1969                 health_poll_entry();
1970                 ret = lttng_poll_wait(&events, -1);
1971                 health_poll_exit();
1972                 if (ret < 0) {
1973                         /*
1974                          * Restart interrupted system call.
1975                          */
1976                         if (errno == EINTR) {
1977                                 goto restart;
1978                         }
1979                         goto error;
1980                 }
1981
1982                 nb_fd = ret;
1983
1984                 /*
1985                  * Process control. The control connection is prioritised so we don't
1986                  * starve it with high throughput tracing data on the data
1987                  * connection.
1988                  */
1989                 for (i = 0; i < nb_fd; i++) {
1990                         /* Fetch once the poll data */
1991                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
1992                         int pollfd = LTTNG_POLL_GETFD(&events, i);
1993
1994                         health_code_update();
1995
1996                         if (!revents) {
1997                                 /* No activity for this FD (poll implementation). */
1998                                 continue;
1999                         }
2000
2001                         /* Thread quit pipe has been closed. Killing thread. */
2002                         ret = check_thread_quit_pipe(pollfd, revents);
2003                         if (ret) {
2004                                 err = 0;
2005                                 goto exit;
2006                         }
2007
2008                         /* Inspect the relay conn pipe for new connection. */
2009                         if (pollfd == live_conn_pipe[0]) {
2010                                 if (revents & LPOLLIN) {
2011                                         struct relay_connection *conn;
2012
2013                                         ret = lttng_read(live_conn_pipe[0],
2014                                                         &conn, sizeof(conn));
2015                                         if (ret < 0) {
2016                                                 goto error;
2017                                         }
2018                                         lttng_poll_add(&events, conn->sock->fd,
2019                                                         LPOLLIN | LPOLLRDHUP);
2020                                         connection_ht_add(viewer_connections_ht, conn);
2021                                         DBG("Connection socket %d added to poll", conn->sock->fd);
2022                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2023                                         ERR("Relay live pipe error");
2024                                         goto error;
2025                                 } else {
2026                                         ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2027                                         goto error;
2028                                 }
2029                         } else {
2030                                 /* Connection activity. */
2031                                 struct relay_connection *conn;
2032
2033                                 conn = connection_get_by_sock(viewer_connections_ht, pollfd);
2034                                 if (!conn) {
2035                                         continue;
2036                                 }
2037
2038                                 if (revents & LPOLLIN) {
2039                                         ret = conn->sock->ops->recvmsg(conn->sock, &recv_hdr,
2040                                                         sizeof(recv_hdr), 0);
2041                                         if (ret <= 0) {
2042                                                 /* Connection closed. */
2043                                                 cleanup_connection_pollfd(&events, pollfd);
2044                                                 /* Put "create" ownership reference. */
2045                                                 connection_put(conn);
2046                                                 DBG("Viewer control conn closed with %d", pollfd);
2047                                         } else {
2048                                                 ret = process_control(&recv_hdr, conn);
2049                                                 if (ret < 0) {
2050                                                         /* Clear the session on error. */
2051                                                         cleanup_connection_pollfd(&events, pollfd);
2052                                                         /* Put "create" ownership reference. */
2053                                                         connection_put(conn);
2054                                                         DBG("Viewer connection closed with %d", pollfd);
2055                                                 }
2056                                         }
2057                                 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2058                                         cleanup_connection_pollfd(&events, pollfd);
2059                                         /* Put "create" ownership reference. */
2060                                         connection_put(conn);
2061                                 } else {
2062                                         ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2063                                         connection_put(conn);
2064                                         goto error;
2065                                 }
2066                                 /* Put local "get_by_sock" reference. */
2067                                 connection_put(conn);
2068                         }
2069                 }
2070         }
2071
2072 exit:
2073 error:
2074         lttng_poll_clean(&events);
2075
2076         /* Cleanup reamaining connection object. */
2077         rcu_read_lock();
2078         cds_lfht_for_each_entry(viewer_connections_ht->ht, &iter.iter,
2079                         destroy_conn,
2080                         sock_n.node) {
2081                 health_code_update();
2082                 connection_put(destroy_conn);
2083         }
2084         rcu_read_unlock();
2085 error_poll_create:
2086         lttng_ht_destroy(viewer_connections_ht);
2087 viewer_connections_ht_error:
2088         /* Close relay conn pipes */
2089         utils_close_pipe(live_conn_pipe);
2090         if (err) {
2091                 DBG("Viewer worker thread exited with error");
2092         }
2093         DBG("Viewer worker thread cleanup complete");
2094 error_testpoint:
2095         if (err) {
2096                 health_error();
2097                 ERR("Health error occurred in %s", __func__);
2098         }
2099         health_unregister(health_relayd);
2100         if (lttng_relay_stop_threads()) {
2101                 ERR("Error stopping threads");
2102         }
2103         rcu_unregister_thread();
2104         return NULL;
2105 }
2106
2107 /*
2108  * Create the relay command pipe to wake thread_manage_apps.
2109  * Closed in cleanup().
2110  */
2111 static int create_conn_pipe(void)
2112 {
2113         return utils_create_pipe_cloexec(live_conn_pipe);
2114 }
2115
2116 int relayd_live_join(void)
2117 {
2118         int ret, retval = 0;
2119         void *status;
2120
2121         ret = pthread_join(live_listener_thread, &status);
2122         if (ret) {
2123                 errno = ret;
2124                 PERROR("pthread_join live listener");
2125                 retval = -1;
2126         }
2127
2128         ret = pthread_join(live_worker_thread, &status);
2129         if (ret) {
2130                 errno = ret;
2131                 PERROR("pthread_join live worker");
2132                 retval = -1;
2133         }
2134
2135         ret = pthread_join(live_dispatcher_thread, &status);
2136         if (ret) {
2137                 errno = ret;
2138                 PERROR("pthread_join live dispatcher");
2139                 retval = -1;
2140         }
2141
2142         cleanup_relayd_live();
2143
2144         return retval;
2145 }
2146
2147 /*
2148  * main
2149  */
2150 int relayd_live_create(struct lttng_uri *uri)
2151 {
2152         int ret = 0, retval = 0;
2153         void *status;
2154         int is_root;
2155
2156         if (!uri) {
2157                 retval = -1;
2158                 goto exit_init_data;
2159         }
2160         live_uri = uri;
2161
2162         /* Check if daemon is UID = 0 */
2163         is_root = !getuid();
2164
2165         if (!is_root) {
2166                 if (live_uri->port < 1024) {
2167                         ERR("Need to be root to use ports < 1024");
2168                         retval = -1;
2169                         goto exit_init_data;
2170                 }
2171         }
2172
2173         /* Setup the thread apps communication pipe. */
2174         if (create_conn_pipe()) {
2175                 retval = -1;
2176                 goto exit_init_data;
2177         }
2178
2179         /* Init relay command queue. */
2180         cds_wfcq_init(&viewer_conn_queue.head, &viewer_conn_queue.tail);
2181
2182         /* Set up max poll set size */
2183         if (lttng_poll_set_max_size()) {
2184                 retval = -1;
2185                 goto exit_init_data;
2186         }
2187
2188         /* Setup the dispatcher thread */
2189         ret = pthread_create(&live_dispatcher_thread, default_pthread_attr(),
2190                         thread_dispatcher, (void *) NULL);
2191         if (ret) {
2192                 errno = ret;
2193                 PERROR("pthread_create viewer dispatcher");
2194                 retval = -1;
2195                 goto exit_dispatcher_thread;
2196         }
2197
2198         /* Setup the worker thread */
2199         ret = pthread_create(&live_worker_thread, default_pthread_attr(),
2200                         thread_worker, NULL);
2201         if (ret) {
2202                 errno = ret;
2203                 PERROR("pthread_create viewer worker");
2204                 retval = -1;
2205                 goto exit_worker_thread;
2206         }
2207
2208         /* Setup the listener thread */
2209         ret = pthread_create(&live_listener_thread, default_pthread_attr(),
2210                         thread_listener, (void *) NULL);
2211         if (ret) {
2212                 errno = ret;
2213                 PERROR("pthread_create viewer listener");
2214                 retval = -1;
2215                 goto exit_listener_thread;
2216         }
2217
2218         /*
2219          * All OK, started all threads.
2220          */
2221         return retval;
2222
2223         /*
2224          * Join on the live_listener_thread should anything be added after
2225          * the live_listener thread's creation.
2226          */
2227
2228 exit_listener_thread:
2229
2230         ret = pthread_join(live_worker_thread, &status);
2231         if (ret) {
2232                 errno = ret;
2233                 PERROR("pthread_join live worker");
2234                 retval = -1;
2235         }
2236 exit_worker_thread:
2237
2238         ret = pthread_join(live_dispatcher_thread, &status);
2239         if (ret) {
2240                 errno = ret;
2241                 PERROR("pthread_join live dispatcher");
2242                 retval = -1;
2243         }
2244 exit_dispatcher_thread:
2245
2246 exit_init_data:
2247         cleanup_relayd_live();
2248
2249         return retval;
2250 }