src/bin/lttng-relayd/main.c

   1 /*
   2  * Copyright (C) 2012 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <getopt.h>
  21 #include <grp.h>
  22 #include <limits.h>
  23 #include <pthread.h>
  24 #include <signal.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/mman.h>
  29 #include <sys/mount.h>
  30 #include <sys/resource.h>
  31 #include <sys/socket.h>
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34 #include <sys/wait.h>
  35 #include <inttypes.h>
  36 #include <urcu/futex.h>
  37 #include <urcu/uatomic.h>
  38 #include <unistd.h>
  39 #include <fcntl.h>
  40 #include <config.h>
  41
  42 #include <lttng/lttng.h>
  43 #include <common/common.h>
  44 #include <common/compat/poll.h>
  45 #include <common/compat/socket.h>
  46 #include <common/defaults.h>
  47 #include <common/futex.h>
  48 #include <common/sessiond-comm/sessiond-comm.h>
  49 #include <common/sessiond-comm/inet.h>
  50 #include <common/hashtable/hashtable.h>
  51 #include <common/sessiond-comm/relayd.h>
  52 #include <common/uri.h>
  53 #include <common/utils.h>
  54
  55 #include "lttng-relayd.h"
  56
  57 /* command line options */
  58 static int opt_daemon;
  59 static char *opt_output_path;
  60 static struct lttng_uri *control_uri;
  61 static struct lttng_uri *data_uri;
  62
  63 const char *progname;
  64 static int is_root;                     /* Set to 1 if the daemon is running as root */
  65
  66 /*
  67  * Quit pipe for all threads. This permits a single cancellation point
  68  * for all threads when receiving an event on the pipe.
  69  */
  70 static int thread_quit_pipe[2] = { -1, -1 };
  71
  72 /*
  73  * This pipe is used to inform the worker thread that a command is queued and
  74  * ready to be processed.
  75  */
  76 static int relay_cmd_pipe[2] = { -1, -1 };
  77
  78 /* Shared between threads */
  79 static int dispatch_thread_exit;
  80
  81 static pthread_t listener_thread;
  82 static pthread_t dispatcher_thread;
  83 static pthread_t worker_thread;
  84
  85 static uint64_t last_relay_stream_id;
  86 static uint64_t last_relay_session_id;
  87
  88 /*
  89  * Relay command queue.
  90  *
  91  * The relay_thread_listener and relay_thread_dispatcher communicate with this
  92  * queue.
  93  */
  94 static struct relay_cmd_queue relay_cmd_queue;
  95
  96 /* buffer allocated at startup, used to store the trace data */
  97 static char *data_buffer;
  98 static unsigned int data_buffer_size;
  99
 100 /*
 101  * usage function on stderr
 102  */
 103 static
 104 void usage(void)
 105 {
 106         fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 107         fprintf(stderr, "  -h, --help                         Display this usage.\n");
 108         fprintf(stderr, "  -d, --daemonize                    Start as a daemon.\n");
 109         fprintf(stderr, "  -C, --control-port                 Control port listening (URI)\n");
 110         fprintf(stderr, "  -D, --data-port                    Data port listening (URI)\n");
 111         fprintf(stderr, "  -o, --output                       Output path for traces (PATH)\n");
 112         fprintf(stderr, "  -v, --verbose                      Verbose mode. Activate DBG() macro.\n");
 113 }
 114
 115 static
 116 int parse_args(int argc, char **argv)
 117 {
 118         int c;
 119         int ret = 0;
 120         char *default_address;
 121
 122         static struct option long_options[] = {
 123                 { "control-port", 1, 0, 'C', },
 124                 { "data-port", 1, 0, 'D', },
 125                 { "daemonize", 0, 0, 'd', },
 126                 { "help", 0, 0, 'h', },
 127                 { "output", 1, 0, 'o', },
 128                 { "verbose", 0, 0, 'v', },
 129                 { NULL, 0, 0, 0, },
 130         };
 131
 132         while (1) {
 133                 int option_index = 0;
 134                 c = getopt_long(argc, argv, "dhv" "C:D:o:",
 135                                 long_options, &option_index);
 136                 if (c == -1) {
 137                         break;
 138                 }
 139
 140                 switch (c) {
 141                 case 0:
 142                         fprintf(stderr, "option %s", long_options[option_index].name);
 143                         if (optarg) {
 144                                 fprintf(stderr, " with arg %s\n", optarg);
 145                         }
 146                         break;
 147                 case 'C':
 148                         ret = uri_parse(optarg, &control_uri);
 149                         if (ret < 0) {
 150                                 ERR("Invalid control URI specified");
 151                                 goto exit;
 152                         }
 153                         if (control_uri->port == 0) {
 154                                 control_uri->port = DEFAULT_NETWORK_CONTROL_PORT;
 155                         }
 156                         break;
 157                 case 'D':
 158                         ret = uri_parse(optarg, &data_uri);
 159                         if (ret < 0) {
 160                                 ERR("Invalid data URI specified");
 161                                 goto exit;
 162                         }
 163                         if (data_uri->port == 0) {
 164                                 data_uri->port = DEFAULT_NETWORK_DATA_PORT;
 165                         }
 166                         break;
 167                 case 'd':
 168                         opt_daemon = 1;
 169                         break;
 170                 case 'h':
 171                         usage();
 172                         exit(EXIT_FAILURE);
 173                 case 'o':
 174                         ret = asprintf(&opt_output_path, "%s", optarg);
 175                         if (ret < 0) {
 176                                 PERROR("asprintf opt_output_path");
 177                                 goto exit;
 178                         }
 179                         break;
 180                 case 'v':
 181                         /* Verbose level can increase using multiple -v */
 182                         lttng_opt_verbose += 1;
 183                         break;
 184                 default:
 185                         /* Unknown option or other error.
 186                          * Error is printed by getopt, just return */
 187                         ret = -1;
 188                         goto exit;
 189                 }
 190         }
 191
 192         /* assign default values */
 193         if (control_uri == NULL) {
 194                 ret = asprintf(&default_address, "tcp://0.0.0.0:%d",
 195                                 DEFAULT_NETWORK_CONTROL_PORT);
 196                 if (ret < 0) {
 197                         PERROR("asprintf default data address");
 198                         goto exit;
 199                 }
 200
 201                 ret = uri_parse(default_address, &control_uri);
 202                 free(default_address);
 203                 if (ret < 0) {
 204                         ERR("Invalid control URI specified");
 205                         goto exit;
 206                 }
 207         }
 208         if (data_uri == NULL) {
 209                 ret = asprintf(&default_address, "tcp://0.0.0.0:%d",
 210                                 DEFAULT_NETWORK_DATA_PORT);
 211                 if (ret < 0) {
 212                         PERROR("asprintf default data address");
 213                         goto exit;
 214                 }
 215
 216                 ret = uri_parse(default_address, &data_uri);
 217                 free(default_address);
 218                 if (ret < 0) {
 219                         ERR("Invalid data URI specified");
 220                         goto exit;
 221                 }
 222         }
 223
 224 exit:
 225         return ret;
 226 }
 227
 228 /*
 229  * Cleanup the daemon
 230  */
 231 static
 232 void cleanup(void)
 233 {
 234         DBG("Cleaning up");
 235
 236         /* free the dynamically allocated opt_output_path */
 237         free(opt_output_path);
 238
 239         /* Close thread quit pipes */
 240         utils_close_pipe(thread_quit_pipe);
 241
 242         uri_free(control_uri);
 243         uri_free(data_uri);
 244 }
 245
 246 /*
 247  * Write to writable pipe used to notify a thread.
 248  */
 249 static
 250 int notify_thread_pipe(int wpipe)
 251 {
 252         int ret;
 253
 254         do {
 255                 ret = write(wpipe, "!", 1);
 256         } while (ret < 0 && errno == EINTR);
 257         if (ret < 0 || ret != 1) {
 258                 PERROR("write poll pipe");
 259         }
 260
 261         return ret;
 262 }
 263
 264 /*
 265  * Stop all threads by closing the thread quit pipe.
 266  */
 267 static
 268 void stop_threads(void)
 269 {
 270         int ret;
 271
 272         /* Stopping all threads */
 273         DBG("Terminating all threads");
 274         ret = notify_thread_pipe(thread_quit_pipe[1]);
 275         if (ret < 0) {
 276                 ERR("write error on thread quit pipe");
 277         }
 278
 279         /* Dispatch thread */
 280         CMM_STORE_SHARED(dispatch_thread_exit, 1);
 281         futex_nto1_wake(&relay_cmd_queue.futex);
 282 }
 283
 284 /*
 285  * Signal handler for the daemon
 286  *
 287  * Simply stop all worker threads, leaving main() return gracefully after
 288  * joining all threads and calling cleanup().
 289  */
 290 static
 291 void sighandler(int sig)
 292 {
 293         switch (sig) {
 294         case SIGPIPE:
 295                 DBG("SIGPIPE caught");
 296                 return;
 297         case SIGINT:
 298                 DBG("SIGINT caught");
 299                 stop_threads();
 300                 break;
 301         case SIGTERM:
 302                 DBG("SIGTERM caught");
 303                 stop_threads();
 304                 break;
 305         default:
 306                 break;
 307         }
 308 }
 309
 310 /*
 311  * Setup signal handler for :
 312  *              SIGINT, SIGTERM, SIGPIPE
 313  */
 314 static
 315 int set_signal_handler(void)
 316 {
 317         int ret = 0;
 318         struct sigaction sa;
 319         sigset_t sigset;
 320
 321         if ((ret = sigemptyset(&sigset)) < 0) {
 322                 PERROR("sigemptyset");
 323                 return ret;
 324         }
 325
 326         sa.sa_handler = sighandler;
 327         sa.sa_mask = sigset;
 328         sa.sa_flags = 0;
 329         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 330                 PERROR("sigaction");
 331                 return ret;
 332         }
 333
 334         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 335                 PERROR("sigaction");
 336                 return ret;
 337         }
 338
 339         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 340                 PERROR("sigaction");
 341                 return ret;
 342         }
 343
 344         DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
 345
 346         return ret;
 347 }
 348
 349 /*
 350  * Init thread quit pipe.
 351  *
 352  * Return -1 on error or 0 if all pipes are created.
 353  */
 354 static
 355 int init_thread_quit_pipe(void)
 356 {
 357         int ret;
 358
 359         ret = utils_create_pipe_cloexec(thread_quit_pipe);
 360
 361         return ret;
 362 }
 363
 364 /*
 365  * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
 366  */
 367 static
 368 int create_thread_poll_set(struct lttng_poll_event *events, int size)
 369 {
 370         int ret;
 371
 372         if (events == NULL || size == 0) {
 373                 ret = -1;
 374                 goto error;
 375         }
 376
 377         ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
 378         if (ret < 0) {
 379                 goto error;
 380         }
 381
 382         /* Add quit pipe */
 383         ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
 384         if (ret < 0) {
 385                 goto error;
 386         }
 387
 388         return 0;
 389
 390 error:
 391         return ret;
 392 }
 393
 394 /*
 395  * Check if the thread quit pipe was triggered.
 396  *
 397  * Return 1 if it was triggered else 0;
 398  */
 399 static
 400 int check_thread_quit_pipe(int fd, uint32_t events)
 401 {
 402         if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
 403                 return 1;
 404         }
 405
 406         return 0;
 407 }
 408
 409 /*
 410  * Create and init socket from uri.
 411  */
 412 static
 413 struct lttcomm_sock *relay_init_sock(struct lttng_uri *uri)
 414 {
 415         int ret;
 416         struct lttcomm_sock *sock = NULL;
 417
 418         sock = lttcomm_alloc_sock_from_uri(uri);
 419         if (sock == NULL) {
 420                 ERR("Allocating socket");
 421                 goto error;
 422         }
 423
 424         ret = lttcomm_create_sock(sock);
 425         if (ret < 0) {
 426                 goto error;
 427         }
 428         DBG("Listening on sock %d", sock->fd);
 429
 430         ret = sock->ops->bind(sock);
 431         if (ret < 0) {
 432                 goto error;
 433         }
 434
 435         ret = sock->ops->listen(sock, -1);
 436         if (ret < 0) {
 437                 goto error;
 438
 439         }
 440
 441         return sock;
 442
 443 error:
 444         if (sock) {
 445                 lttcomm_destroy_sock(sock);
 446         }
 447         return NULL;
 448 }
 449
 450 /*
 451  * Return nonzero if stream needs to be closed.
 452  */
 453 static
 454 int close_stream_check(struct relay_stream *stream)
 455 {
 456
 457         if (stream->close_flag && stream->prev_seq == stream->last_net_seq_num) {
 458                 /*
 459                  * We are about to close the stream so set the data pending flag to 1
 460                  * which will make the end data pending command skip the stream which
 461                  * is now closed and ready. Note that after proceeding to a file close,
 462                  * the written file is ready for reading.
 463                  */
 464                 stream->data_pending_check_done = 1;
 465                 return 1;
 466         }
 467         return 0;
 468 }
 469
 470 /*
 471  * This thread manages the listening for new connections on the network
 472  */
 473 static
 474 void *relay_thread_listener(void *data)
 475 {
 476         int i, ret, pollfd, err = -1;
 477         int val = 1;
 478         uint32_t revents, nb_fd;
 479         struct lttng_poll_event events;
 480         struct lttcomm_sock *control_sock, *data_sock;
 481
 482         DBG("[thread] Relay listener started");
 483
 484         control_sock = relay_init_sock(control_uri);
 485         if (!control_sock) {
 486                 goto error_sock_control;
 487         }
 488
 489         data_sock = relay_init_sock(data_uri);
 490         if (!data_sock) {
 491                 goto error_sock_relay;
 492         }
 493
 494         /*
 495          * Pass 3 as size here for the thread quit pipe, control and data socket.
 496          */
 497         ret = create_thread_poll_set(&events, 3);
 498         if (ret < 0) {
 499                 goto error_create_poll;
 500         }
 501
 502         /* Add the control socket */
 503         ret = lttng_poll_add(&events, control_sock->fd, LPOLLIN | LPOLLRDHUP);
 504         if (ret < 0) {
 505                 goto error_poll_add;
 506         }
 507
 508         /* Add the data socket */
 509         ret = lttng_poll_add(&events, data_sock->fd, LPOLLIN | LPOLLRDHUP);
 510         if (ret < 0) {
 511                 goto error_poll_add;
 512         }
 513
 514         while (1) {
 515                 DBG("Listener accepting connections");
 516
 517 restart:
 518                 ret = lttng_poll_wait(&events, -1);
 519                 if (ret < 0) {
 520                         /*
 521                          * Restart interrupted system call.
 522                          */
 523                         if (errno == EINTR) {
 524                                 goto restart;
 525                         }
 526                         goto error;
 527                 }
 528
 529                 nb_fd = ret;
 530
 531                 DBG("Relay new connection received");
 532                 for (i = 0; i < nb_fd; i++) {
 533                         /* Fetch once the poll data */
 534                         revents = LTTNG_POLL_GETEV(&events, i);
 535                         pollfd = LTTNG_POLL_GETFD(&events, i);
 536
 537                         /* Thread quit pipe has been closed. Killing thread. */
 538                         ret = check_thread_quit_pipe(pollfd, revents);
 539                         if (ret) {
 540                                 err = 0;
 541                                 goto exit;
 542                         }
 543
 544                         if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
 545                                 ERR("socket poll error");
 546                                 goto error;
 547                         } else if (revents & LPOLLIN) {
 548                                 /*
 549                                  * Get allocated in this thread,
 550                                  * enqueued to a global queue, dequeued
 551                                  * and freed in the worker thread.
 552                                  */
 553                                 struct relay_command *relay_cmd;
 554                                 struct lttcomm_sock *newsock;
 555
 556                                 relay_cmd = zmalloc(sizeof(struct relay_command));
 557                                 if (relay_cmd == NULL) {
 558                                         PERROR("relay command zmalloc");
 559                                         goto error;
 560                                 }
 561
 562                                 if (pollfd == data_sock->fd) {
 563                                         newsock = data_sock->ops->accept(data_sock);
 564                                         if (!newsock) {
 565                                                 PERROR("accepting data sock");
 566                                                 free(relay_cmd);
 567                                                 goto error;
 568                                         }
 569                                         relay_cmd->type = RELAY_DATA;
 570                                         DBG("Relay data connection accepted, socket %d", newsock->fd);
 571                                 } else {
 572                                         assert(pollfd == control_sock->fd);
 573                                         newsock = control_sock->ops->accept(control_sock);
 574                                         if (!newsock) {
 575                                                 PERROR("accepting control sock");
 576                                                 free(relay_cmd);
 577                                                 goto error;
 578                                         }
 579                                         relay_cmd->type = RELAY_CONTROL;
 580                                         DBG("Relay control connection accepted, socket %d", newsock->fd);
 581                                 }
 582                                 ret = setsockopt(newsock->fd, SOL_SOCKET, SO_REUSEADDR,
 583                                                 &val, sizeof(int));
 584                                 if (ret < 0) {
 585                                         PERROR("setsockopt inet");
 586                                         lttcomm_destroy_sock(newsock);
 587                                         free(relay_cmd);
 588                                         goto error;
 589                                 }
 590                                 relay_cmd->sock = newsock;
 591                                 /*
 592                                  * Lock free enqueue the request.
 593                                  */
 594                                 cds_wfq_enqueue(&relay_cmd_queue.queue, &relay_cmd->node);
 595
 596                                 /*
 597                                  * Wake the dispatch queue futex. Implicit memory
 598                                  * barrier with the exchange in cds_wfq_enqueue.
 599                                  */
 600                                 futex_nto1_wake(&relay_cmd_queue.futex);
 601                         }
 602                 }
 603         }
 604
 605 exit:
 606 error:
 607 error_poll_add:
 608         lttng_poll_clean(&events);
 609 error_create_poll:
 610         if (data_sock->fd >= 0) {
 611                 ret = data_sock->ops->close(data_sock);
 612                 if (ret) {
 613                         PERROR("close");
 614                 }
 615         }
 616         lttcomm_destroy_sock(data_sock);
 617 error_sock_relay:
 618         if (control_sock->fd >= 0) {
 619                 ret = control_sock->ops->close(control_sock);
 620                 if (ret) {
 621                         PERROR("close");
 622                 }
 623         }
 624         lttcomm_destroy_sock(control_sock);
 625 error_sock_control:
 626         if (err) {
 627                 DBG("Thread exited with error");
 628         }
 629         DBG("Relay listener thread cleanup complete");
 630         stop_threads();
 631         return NULL;
 632 }
 633
 634 /*
 635  * This thread manages the dispatching of the requests to worker threads
 636  */
 637 static
 638 void *relay_thread_dispatcher(void *data)
 639 {
 640         int ret;
 641         struct cds_wfq_node *node;
 642         struct relay_command *relay_cmd = NULL;
 643
 644         DBG("[thread] Relay dispatcher started");
 645
 646         while (!CMM_LOAD_SHARED(dispatch_thread_exit)) {
 647                 /* Atomically prepare the queue futex */
 648                 futex_nto1_prepare(&relay_cmd_queue.futex);
 649
 650                 do {
 651                         /* Dequeue commands */
 652                         node = cds_wfq_dequeue_blocking(&relay_cmd_queue.queue);
 653                         if (node == NULL) {
 654                                 DBG("Woken up but nothing in the relay command queue");
 655                                 /* Continue thread execution */
 656                                 break;
 657                         }
 658
 659                         relay_cmd = caa_container_of(node, struct relay_command, node);
 660                         DBG("Dispatching request waiting on sock %d", relay_cmd->sock->fd);
 661
 662                         /*
 663                          * Inform worker thread of the new request. This
 664                          * call is blocking so we can be assured that the data will be read
 665                          * at some point in time or wait to the end of the world :)
 666                          */
 667                         do {
 668                                 ret = write(relay_cmd_pipe[1], relay_cmd,
 669                                                 sizeof(struct relay_command));
 670                         } while (ret < 0 && errno == EINTR);
 671                         free(relay_cmd);
 672                         if (ret < 0 || ret != sizeof(struct relay_command)) {
 673                                 PERROR("write cmd pipe");
 674                                 goto error;
 675                         }
 676                 } while (node != NULL);
 677
 678                 /* Futex wait on queue. Blocking call on futex() */
 679                 futex_nto1_wait(&relay_cmd_queue.futex);
 680         }
 681
 682 error:
 683         DBG("Dispatch thread dying");
 684         stop_threads();
 685         return NULL;
 686 }
 687
 688 /*
 689  *  config_get_default_path
 690  *
 691  *  Returns the HOME directory path. Caller MUST NOT free(3) the return pointer.
 692  */
 693 static
 694 char *config_get_default_path(void)
 695 {
 696         return getenv("HOME");
 697 }
 698
 699 static
 700 char *create_output_path_auto(char *path_name)
 701 {
 702         int ret;
 703         char *traces_path = NULL;
 704         char *alloc_path = NULL;
 705         char *default_path;
 706
 707         default_path = config_get_default_path();
 708         if (default_path == NULL) {
 709                 ERR("Home path not found.\n \
 710                                 Please specify an output path using -o, --output PATH");
 711                 goto exit;
 712         }
 713         alloc_path = strdup(default_path);
 714         if (alloc_path == NULL) {
 715                 PERROR("Path allocation");
 716                 goto exit;
 717         }
 718         ret = asprintf(&traces_path, "%s/" DEFAULT_TRACE_DIR_NAME
 719                         "/%s", alloc_path, path_name);
 720         if (ret < 0) {
 721                 PERROR("asprintf trace dir name");
 722                 goto exit;
 723         }
 724 exit:
 725         free(alloc_path);
 726         return traces_path;
 727 }
 728
 729 static
 730 char *create_output_path_noauto(char *path_name)
 731 {
 732         int ret;
 733         char *traces_path = NULL;
 734         char *full_path;
 735
 736         full_path = utils_expand_path(opt_output_path);
 737         if (!full_path) {
 738                 goto exit;
 739         }
 740
 741         ret = asprintf(&traces_path, "%s/%s", full_path, path_name);
 742         if (ret < 0) {
 743                 PERROR("asprintf trace dir name");
 744                 goto exit;
 745         }
 746 exit:
 747         free(full_path);
 748         return traces_path;
 749 }
 750
 751 /*
 752  * create_output_path: create the output trace directory
 753  */
 754 static
 755 char *create_output_path(char *path_name)
 756 {
 757         if (opt_output_path == NULL) {
 758                 return create_output_path_auto(path_name);
 759         } else {
 760                 return create_output_path_noauto(path_name);
 761         }
 762 }
 763
 764 /*
 765  * Get stream from stream id.
 766  * Need to be called with RCU read-side lock held.
 767  */
 768 static
 769 struct relay_stream *relay_stream_from_stream_id(uint64_t stream_id,
 770                 struct lttng_ht *streams_ht)
 771 {
 772         struct lttng_ht_node_ulong *node;
 773         struct lttng_ht_iter iter;
 774         struct relay_stream *ret;
 775
 776         lttng_ht_lookup(streams_ht,
 777                         (void *)((unsigned long) stream_id),
 778                         &iter);
 779         node = lttng_ht_iter_get_node_ulong(&iter);
 780         if (node == NULL) {
 781                 DBG("Relay stream %" PRIu64 " not found", stream_id);
 782                 ret = NULL;
 783                 goto end;
 784         }
 785
 786         ret = caa_container_of(node, struct relay_stream, stream_n);
 787
 788 end:
 789         return ret;
 790 }
 791
 792 static
 793 void deferred_free_stream(struct rcu_head *head)
 794 {
 795         struct relay_stream *stream =
 796                 caa_container_of(head, struct relay_stream, rcu_node);
 797         free(stream);
 798 }
 799
 800 /*
 801  * relay_delete_session: Free all memory associated with a session and
 802  * close all the FDs
 803  */
 804 static
 805 void relay_delete_session(struct relay_command *cmd, struct lttng_ht *streams_ht)
 806 {
 807         struct lttng_ht_iter iter;
 808         struct lttng_ht_node_ulong *node;
 809         struct relay_stream *stream;
 810         int ret;
 811
 812         if (!cmd->session) {
 813                 return;
 814         }
 815
 816         DBG("Relay deleting session %" PRIu64, cmd->session->id);
 817
 818         rcu_read_lock();
 819         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, node, node) {
 820                 node = lttng_ht_iter_get_node_ulong(&iter);
 821                 if (node) {
 822                         stream = caa_container_of(node,
 823                                         struct relay_stream, stream_n);
 824                         if (stream->session == cmd->session) {
 825                                 ret = close(stream->fd);
 826                                 if (ret < 0) {
 827                                         PERROR("close stream fd on delete session");
 828                                 }
 829                                 ret = lttng_ht_del(streams_ht, &iter);
 830                                 assert(!ret);
 831                                 call_rcu(&stream->rcu_node,
 832                                         deferred_free_stream);
 833                         }
 834                 }
 835         }
 836         rcu_read_unlock();
 837
 838         free(cmd->session);
 839 }
 840
 841 /*
 842  * Handle the RELAYD_CREATE_SESSION command.
 843  *
 844  * On success, send back the session id or else return a negative value.
 845  */
 846 static
 847 int relay_create_session(struct lttcomm_relayd_hdr *recv_hdr,
 848                 struct relay_command *cmd)
 849 {
 850         int ret = 0, send_ret;
 851         struct relay_session *session;
 852         struct lttcomm_relayd_status_session reply;
 853
 854         assert(recv_hdr);
 855         assert(cmd);
 856
 857         memset(&reply, 0, sizeof(reply));
 858
 859         session = zmalloc(sizeof(struct relay_session));
 860         if (session == NULL) {
 861                 PERROR("relay session zmalloc");
 862                 ret = -1;
 863                 goto error;
 864         }
 865
 866         session->id = ++last_relay_session_id;
 867         session->sock = cmd->sock;
 868         cmd->session = session;
 869
 870         reply.session_id = htobe64(session->id);
 871
 872         DBG("Created session %" PRIu64, session->id);
 873
 874 error:
 875         if (ret < 0) {
 876                 reply.ret_code = htobe32(LTTNG_ERR_FATAL);
 877         } else {
 878                 reply.ret_code = htobe32(LTTNG_OK);
 879         }
 880
 881         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
 882         if (send_ret < 0) {
 883                 ERR("Relayd sending session id");
 884                 ret = send_ret;
 885         }
 886
 887         return ret;
 888 }
 889
 890 /*
 891  * relay_add_stream: allocate a new stream for a session
 892  */
 893 static
 894 int relay_add_stream(struct lttcomm_relayd_hdr *recv_hdr,
 895                 struct relay_command *cmd, struct lttng_ht *streams_ht)
 896 {
 897         struct relay_session *session = cmd->session;
 898         struct lttcomm_relayd_add_stream stream_info;
 899         struct relay_stream *stream = NULL;
 900         struct lttcomm_relayd_status_stream reply;
 901         char *path = NULL, *root_path = NULL;
 902         int ret, send_ret;
 903
 904         if (!session || cmd->version_check_done == 0) {
 905                 ERR("Trying to add a stream before version check");
 906                 ret = -1;
 907                 goto end_no_session;
 908         }
 909
 910         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
 911                         sizeof(struct lttcomm_relayd_add_stream), 0);
 912         if (ret < sizeof(struct lttcomm_relayd_add_stream)) {
 913                 if (ret == 0) {
 914                         /* Orderly shutdown. Not necessary to print an error. */
 915                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
 916                 } else {
 917                         ERR("Relay didn't receive valid add_stream struct size : %d", ret);
 918                 }
 919                 ret = -1;
 920                 goto end_no_session;
 921         }
 922         stream = zmalloc(sizeof(struct relay_stream));
 923         if (stream == NULL) {
 924                 PERROR("relay stream zmalloc");
 925                 ret = -1;
 926                 goto end_no_session;
 927         }
 928
 929         rcu_read_lock();
 930         stream->stream_handle = ++last_relay_stream_id;
 931         stream->prev_seq = -1ULL;
 932         stream->session = session;
 933
 934         root_path = create_output_path(stream_info.pathname);
 935         if (!root_path) {
 936                 ret = -1;
 937                 goto end;
 938         }
 939         ret = utils_mkdir_recursive(root_path, S_IRWXU | S_IRWXG);
 940         if (ret < 0) {
 941                 ERR("relay creating output directory");
 942                 goto end;
 943         }
 944
 945         ret = asprintf(&path, "%s/%s", root_path, stream_info.channel_name);
 946         if (ret < 0) {
 947                 PERROR("asprintf stream path");
 948                 path = NULL;
 949                 goto end;
 950         }
 951
 952         ret = open(path, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
 953         if (ret < 0) {
 954                 PERROR("Relay creating trace file");
 955                 goto end;
 956         }
 957
 958         stream->fd = ret;
 959         DBG("Tracefile %s created", path);
 960
 961         lttng_ht_node_init_ulong(&stream->stream_n,
 962                         (unsigned long) stream->stream_handle);
 963         lttng_ht_add_unique_ulong(streams_ht,
 964                         &stream->stream_n);
 965
 966         DBG("Relay new stream added %s", stream_info.channel_name);
 967
 968 end:
 969         free(path);
 970         free(root_path);
 971
 972         reply.handle = htobe64(stream->stream_handle);
 973         /* send the session id to the client or a negative return code on error */
 974         if (ret < 0) {
 975                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
 976                 /* stream was not properly added to the ht, so free it */
 977                 free(stream);
 978         } else {
 979                 reply.ret_code = htobe32(LTTNG_OK);
 980         }
 981
 982         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
 983                         sizeof(struct lttcomm_relayd_status_stream), 0);
 984         if (send_ret < 0) {
 985                 ERR("Relay sending stream id");
 986                 ret = send_ret;
 987         }
 988         rcu_read_unlock();
 989
 990 end_no_session:
 991         return ret;
 992 }
 993
 994 /*
 995  * relay_close_stream: close a specific stream
 996  */
 997 static
 998 int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
 999                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1000 {
1001         struct relay_session *session = cmd->session;
1002         struct lttcomm_relayd_close_stream stream_info;
1003         struct lttcomm_relayd_generic_reply reply;
1004         struct relay_stream *stream;
1005         int ret, send_ret;
1006         struct lttng_ht_iter iter;
1007
1008         DBG("Close stream received");
1009
1010         if (!session || cmd->version_check_done == 0) {
1011                 ERR("Trying to close a stream before version check");
1012                 ret = -1;
1013                 goto end_no_session;
1014         }
1015
1016         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
1017                         sizeof(struct lttcomm_relayd_close_stream), 0);
1018         if (ret < sizeof(struct lttcomm_relayd_close_stream)) {
1019                 if (ret == 0) {
1020                         /* Orderly shutdown. Not necessary to print an error. */
1021                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1022                 } else {
1023                         ERR("Relay didn't receive valid add_stream struct size : %d", ret);
1024                 }
1025                 ret = -1;
1026                 goto end_no_session;
1027         }
1028
1029         rcu_read_lock();
1030         stream = relay_stream_from_stream_id(be64toh(stream_info.stream_id),
1031                         streams_ht);
1032         if (!stream) {
1033                 ret = -1;
1034                 goto end_unlock;
1035         }
1036
1037         stream->last_net_seq_num = be64toh(stream_info.last_net_seq_num);
1038         stream->close_flag = 1;
1039
1040         if (close_stream_check(stream)) {
1041                 int delret;
1042
1043                 delret = close(stream->fd);
1044                 if (delret < 0) {
1045                         PERROR("close stream");
1046                 }
1047                 iter.iter.node = &stream->stream_n.node;
1048                 delret = lttng_ht_del(streams_ht, &iter);
1049                 assert(!delret);
1050                 call_rcu(&stream->rcu_node,
1051                                 deferred_free_stream);
1052                 DBG("Closed tracefile %d from close stream", stream->fd);
1053         }
1054
1055 end_unlock:
1056         rcu_read_unlock();
1057
1058         if (ret < 0) {
1059                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1060         } else {
1061                 reply.ret_code = htobe32(LTTNG_OK);
1062         }
1063         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1064                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1065         if (send_ret < 0) {
1066                 ERR("Relay sending stream id");
1067                 ret = send_ret;
1068         }
1069
1070 end_no_session:
1071         return ret;
1072 }
1073
1074 /*
1075  * relay_unknown_command: send -1 if received unknown command
1076  */
1077 static
1078 void relay_unknown_command(struct relay_command *cmd)
1079 {
1080         struct lttcomm_relayd_generic_reply reply;
1081         int ret;
1082
1083         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1084         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1085                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1086         if (ret < 0) {
1087                 ERR("Relay sending unknown command");
1088         }
1089 }
1090
1091 /*
1092  * relay_start: send an acknowledgment to the client to tell if we are
1093  * ready to receive data. We are ready if a session is established.
1094  */
1095 static
1096 int relay_start(struct lttcomm_relayd_hdr *recv_hdr,
1097                 struct relay_command *cmd)
1098 {
1099         int ret = htobe32(LTTNG_OK);
1100         struct lttcomm_relayd_generic_reply reply;
1101         struct relay_session *session = cmd->session;
1102
1103         if (!session) {
1104                 DBG("Trying to start the streaming without a session established");
1105                 ret = htobe32(LTTNG_ERR_UNK);
1106         }
1107
1108         reply.ret_code = ret;
1109         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1110                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1111         if (ret < 0) {
1112                 ERR("Relay sending start ack");
1113         }
1114
1115         return ret;
1116 }
1117
1118 /*
1119  * Append padding to the file pointed by the file descriptor fd.
1120  */
1121 static int write_padding_to_file(int fd, uint32_t size)
1122 {
1123         int ret = 0;
1124         char *zeros;
1125
1126         if (size == 0) {
1127                 goto end;
1128         }
1129
1130         zeros = zmalloc(size);
1131         if (zeros == NULL) {
1132                 PERROR("zmalloc zeros for padding");
1133                 ret = -1;
1134                 goto end;
1135         }
1136
1137         do {
1138                 ret = write(fd, zeros, size);
1139         } while (ret < 0 && errno == EINTR);
1140         if (ret < 0 || ret != size) {
1141                 PERROR("write padding to file");
1142         }
1143
1144         free(zeros);
1145
1146 end:
1147         return ret;
1148 }
1149
1150 /*
1151  * relay_recv_metadata: receive the metada for the session.
1152  */
1153 static
1154 int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
1155                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1156 {
1157         int ret = htobe32(LTTNG_OK);
1158         struct relay_session *session = cmd->session;
1159         struct lttcomm_relayd_metadata_payload *metadata_struct;
1160         struct relay_stream *metadata_stream;
1161         uint64_t data_size, payload_size;
1162
1163         if (!session) {
1164                 ERR("Metadata sent before version check");
1165                 ret = -1;
1166                 goto end;
1167         }
1168
1169         data_size = payload_size = be64toh(recv_hdr->data_size);
1170         if (data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
1171                 ERR("Incorrect data size");
1172                 ret = -1;
1173                 goto end;
1174         }
1175         payload_size -= sizeof(struct lttcomm_relayd_metadata_payload);
1176
1177         if (data_buffer_size < data_size) {
1178                 /* In case the realloc fails, we can free the memory */
1179                 char *tmp_data_ptr;
1180
1181                 tmp_data_ptr = realloc(data_buffer, data_size);
1182                 if (!tmp_data_ptr) {
1183                         ERR("Allocating data buffer");
1184                         free(data_buffer);
1185                         ret = -1;
1186                         goto end;
1187                 }
1188                 data_buffer = tmp_data_ptr;
1189                 data_buffer_size = data_size;
1190         }
1191         memset(data_buffer, 0, data_size);
1192         DBG2("Relay receiving metadata, waiting for %" PRIu64 " bytes", data_size);
1193         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1194         if (ret < 0 || ret != data_size) {
1195                 if (ret == 0) {
1196                         /* Orderly shutdown. Not necessary to print an error. */
1197                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1198                 } else {
1199                         ERR("Relay didn't receive the whole metadata");
1200                 }
1201                 ret = -1;
1202                 goto end;
1203         }
1204         metadata_struct = (struct lttcomm_relayd_metadata_payload *) data_buffer;
1205
1206         rcu_read_lock();
1207         metadata_stream = relay_stream_from_stream_id(
1208                         be64toh(metadata_struct->stream_id), streams_ht);
1209         if (!metadata_stream) {
1210                 ret = -1;
1211                 goto end_unlock;
1212         }
1213
1214         do {
1215                 ret = write(metadata_stream->fd, metadata_struct->payload,
1216                                 payload_size);
1217         } while (ret < 0 && errno == EINTR);
1218         if (ret < 0 || ret != payload_size) {
1219                 ERR("Relay error writing metadata on file");
1220                 ret = -1;
1221                 goto end_unlock;
1222         }
1223
1224         ret = write_padding_to_file(metadata_stream->fd,
1225                         be32toh(metadata_struct->padding_size));
1226         if (ret < 0) {
1227                 goto end_unlock;
1228         }
1229
1230         DBG2("Relay metadata written");
1231
1232 end_unlock:
1233         rcu_read_unlock();
1234 end:
1235         return ret;
1236 }
1237
1238 /*
1239  * relay_send_version: send relayd version number
1240  */
1241 static
1242 int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
1243                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1244 {
1245         int ret;
1246         struct lttcomm_relayd_version reply, msg;
1247
1248         assert(cmd);
1249
1250         cmd->version_check_done = 1;
1251
1252         /* Get version from the other side. */
1253         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1254         if (ret < 0 || ret != sizeof(msg)) {
1255                 if (ret == 0) {
1256                         /* Orderly shutdown. Not necessary to print an error. */
1257                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1258                 } else {
1259                         ERR("Relay failed to receive the version values.");
1260                 }
1261                 ret = -1;
1262                 goto end;
1263         }
1264
1265         ret = sscanf(VERSION, "%10u.%10u", &reply.major, &reply.minor);
1266         if (ret < 2) {
1267                 ERR("Error in scanning version");
1268                 ret = -1;
1269                 goto end;
1270         }
1271         reply.major = htobe32(reply.major);
1272         reply.minor = htobe32(reply.minor);
1273         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1274                         sizeof(struct lttcomm_relayd_version), 0);
1275         if (ret < 0) {
1276                 ERR("Relay sending version");
1277         }
1278
1279         /* Major versions must be the same */
1280         if (reply.major != be32toh(msg.major)) {
1281                 DBG("Incompatible major versions, deleting session");
1282                 relay_delete_session(cmd, streams_ht);
1283                 ret = 0;
1284                 goto end;
1285         }
1286
1287         cmd->session->major = reply.major;
1288         /* We adapt to the lowest compatible version */
1289         if (reply.minor <= be32toh(msg.minor)) {
1290                 cmd->session->minor = reply.minor;
1291         } else {
1292                 cmd->session->minor = be32toh(msg.minor);
1293         }
1294
1295         DBG("Version check done using protocol %u.%u", cmd->session->major,
1296                         cmd->session->minor);
1297
1298 end:
1299         return ret;
1300 }
1301
1302 /*
1303  * Check for data pending for a given stream id from the session daemon.
1304  */
1305 static
1306 int relay_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1307                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1308 {
1309         struct relay_session *session = cmd->session;
1310         struct lttcomm_relayd_data_pending msg;
1311         struct lttcomm_relayd_generic_reply reply;
1312         struct relay_stream *stream;
1313         int ret;
1314         uint64_t last_net_seq_num, stream_id;
1315
1316         DBG("Data pending command received");
1317
1318         if (!session || cmd->version_check_done == 0) {
1319                 ERR("Trying to check for data before version check");
1320                 ret = -1;
1321                 goto end_no_session;
1322         }
1323
1324         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1325         if (ret < sizeof(msg)) {
1326                 if (ret == 0) {
1327                         /* Orderly shutdown. Not necessary to print an error. */
1328                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1329                 } else {
1330                         ERR("Relay didn't receive valid data_pending struct size : %d",
1331                                         ret);
1332                 }
1333                 ret = -1;
1334                 goto end_no_session;
1335         }
1336
1337         stream_id = be64toh(msg.stream_id);
1338         last_net_seq_num = be64toh(msg.last_net_seq_num);
1339
1340         rcu_read_lock();
1341         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1342         if (stream == NULL) {
1343                 ret = -1;
1344                 goto end_unlock;
1345         }
1346
1347         DBG("Data pending for stream id %" PRIu64 " prev_seq %" PRIu64
1348                         " and last_seq %" PRIu64, stream_id, stream->prev_seq,
1349                         last_net_seq_num);
1350
1351         /* Avoid wrapping issue */
1352         if (((int64_t) (stream->prev_seq - last_net_seq_num)) >= 0) {
1353                 /* Data has in fact been written and is NOT pending */
1354                 ret = 0;
1355         } else {
1356                 /* Data still being streamed thus pending */
1357                 ret = 1;
1358         }
1359
1360         /* Pending check is now done. */
1361         stream->data_pending_check_done = 1;
1362
1363 end_unlock:
1364         rcu_read_unlock();
1365
1366         reply.ret_code = htobe32(ret);
1367         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1368         if (ret < 0) {
1369                 ERR("Relay data pending ret code failed");
1370         }
1371
1372 end_no_session:
1373         return ret;
1374 }
1375
1376 /*
1377  * Wait for the control socket to reach a quiescent state.
1378  *
1379  * Note that for now, when receiving this command from the session daemon, this
1380  * means that every subsequent commands or data received on the control socket
1381  * has been handled. So, this is why we simply return OK here.
1382  */
1383 static
1384 int relay_quiescent_control(struct lttcomm_relayd_hdr *recv_hdr,
1385                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1386 {
1387         int ret;
1388         uint64_t stream_id;
1389         struct relay_stream *stream;
1390         struct lttng_ht_iter iter;
1391         struct lttcomm_relayd_quiescent_control msg;
1392         struct lttcomm_relayd_generic_reply reply;
1393
1394         DBG("Checking quiescent state on control socket");
1395
1396         if (!cmd->session || cmd->version_check_done == 0) {
1397                 ERR("Trying to check for data before version check");
1398                 ret = -1;
1399                 goto end_no_session;
1400         }
1401
1402         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1403         if (ret < sizeof(msg)) {
1404                 if (ret == 0) {
1405                         /* Orderly shutdown. Not necessary to print an error. */
1406                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1407                 } else {
1408                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1409                                         ret);
1410                 }
1411                 ret = -1;
1412                 goto end_no_session;
1413         }
1414
1415         stream_id = be64toh(msg.stream_id);
1416
1417         rcu_read_lock();
1418         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1419                 if (stream->stream_handle == stream_id) {
1420                         stream->data_pending_check_done = 1;
1421                         DBG("Relay quiescent control pending flag set to %" PRIu64,
1422                                         stream_id);
1423                         break;
1424                 }
1425         }
1426         rcu_read_unlock();
1427
1428         reply.ret_code = htobe32(LTTNG_OK);
1429         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1430         if (ret < 0) {
1431                 ERR("Relay data quiescent control ret code failed");
1432         }
1433
1434 end_no_session:
1435         return ret;
1436 }
1437
1438 /*
1439  * Initialize a data pending command. This means that a client is about to ask
1440  * for data pending for each stream he/she holds. Simply iterate over all
1441  * streams of a session and set the data_pending_check_done flag.
1442  *
1443  * This command returns to the client a LTTNG_OK code.
1444  */
1445 static
1446 int relay_begin_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1447                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1448 {
1449         int ret;
1450         struct lttng_ht_iter iter;
1451         struct lttcomm_relayd_begin_data_pending msg;
1452         struct lttcomm_relayd_generic_reply reply;
1453         struct relay_stream *stream;
1454         uint64_t session_id;
1455
1456         assert(recv_hdr);
1457         assert(cmd);
1458         assert(streams_ht);
1459
1460         DBG("Init streams for data pending");
1461
1462         if (!cmd->session || cmd->version_check_done == 0) {
1463                 ERR("Trying to check for data before version check");
1464                 ret = -1;
1465                 goto end_no_session;
1466         }
1467
1468         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1469         if (ret < sizeof(msg)) {
1470                 if (ret == 0) {
1471                         /* Orderly shutdown. Not necessary to print an error. */
1472                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1473                 } else {
1474                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1475                                         ret);
1476                 }
1477                 ret = -1;
1478                 goto end_no_session;
1479         }
1480
1481         session_id = be64toh(msg.session_id);
1482
1483         /*
1484          * Iterate over all streams to set the begin data pending flag. For now, the
1485          * streams are indexed by stream handle so we have to iterate over all
1486          * streams to find the one associated with the right session_id.
1487          */
1488         rcu_read_lock();
1489         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1490                 if (stream->session->id == session_id) {
1491                         stream->data_pending_check_done = 0;
1492                         DBG("Set begin data pending flag to stream %" PRIu64,
1493                                         stream->stream_handle);
1494                 }
1495         }
1496         rcu_read_unlock();
1497
1498         /* All good, send back reply. */
1499         reply.ret_code = htobe32(LTTNG_OK);
1500
1501         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1502         if (ret < 0) {
1503                 ERR("Relay begin data pending send reply failed");
1504         }
1505
1506 end_no_session:
1507         return ret;
1508 }
1509
1510 /*
1511  * End data pending command. This will check, for a given session id, if each
1512  * stream associated with it has its data_pending_check_done flag set. If not,
1513  * this means that the client lost track of the stream but the data is still
1514  * being streamed on our side. In this case, we inform the client that data is
1515  * inflight.
1516  *
1517  * Return to the client if there is data in flight or not with a ret_code.
1518  */
1519 static
1520 int relay_end_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1521                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1522 {
1523         int ret;
1524         struct lttng_ht_iter iter;
1525         struct lttcomm_relayd_end_data_pending msg;
1526         struct lttcomm_relayd_generic_reply reply;
1527         struct relay_stream *stream;
1528         uint64_t session_id;
1529         uint32_t is_data_inflight = 0;
1530
1531         assert(recv_hdr);
1532         assert(cmd);
1533         assert(streams_ht);
1534
1535         DBG("End data pending command");
1536
1537         if (!cmd->session || cmd->version_check_done == 0) {
1538                 ERR("Trying to check for data before version check");
1539                 ret = -1;
1540                 goto end_no_session;
1541         }
1542
1543         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1544         if (ret < sizeof(msg)) {
1545                 if (ret == 0) {
1546                         /* Orderly shutdown. Not necessary to print an error. */
1547                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1548                 } else {
1549                         ERR("Relay didn't receive valid end data_pending struct size: %d",
1550                                         ret);
1551                 }
1552                 ret = -1;
1553                 goto end_no_session;
1554         }
1555
1556         session_id = be64toh(msg.session_id);
1557
1558         /* Iterate over all streams to see if the begin data pending flag is set. */
1559         rcu_read_lock();
1560         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1561                 if (stream->session->id == session_id &&
1562                                 !stream->data_pending_check_done) {
1563                         is_data_inflight = 1;
1564                         DBG("Data is still in flight for stream %" PRIu64,
1565                                         stream->stream_handle);
1566                         break;
1567                 }
1568         }
1569         rcu_read_unlock();
1570
1571         /* All good, send back reply. */
1572         reply.ret_code = htobe32(is_data_inflight);
1573
1574         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1575         if (ret < 0) {
1576                 ERR("Relay end data pending send reply failed");
1577         }
1578
1579 end_no_session:
1580         return ret;
1581 }
1582
1583 /*
1584  * relay_process_control: Process the commands received on the control socket
1585  */
1586 static
1587 int relay_process_control(struct lttcomm_relayd_hdr *recv_hdr,
1588                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1589 {
1590         int ret = 0;
1591
1592         switch (be32toh(recv_hdr->cmd)) {
1593         case RELAYD_CREATE_SESSION:
1594                 ret = relay_create_session(recv_hdr, cmd);
1595                 break;
1596         case RELAYD_ADD_STREAM:
1597                 ret = relay_add_stream(recv_hdr, cmd, streams_ht);
1598                 break;
1599         case RELAYD_START_DATA:
1600                 ret = relay_start(recv_hdr, cmd);
1601                 break;
1602         case RELAYD_SEND_METADATA:
1603                 ret = relay_recv_metadata(recv_hdr, cmd, streams_ht);
1604                 break;
1605         case RELAYD_VERSION:
1606                 ret = relay_send_version(recv_hdr, cmd, streams_ht);
1607                 break;
1608         case RELAYD_CLOSE_STREAM:
1609                 ret = relay_close_stream(recv_hdr, cmd, streams_ht);
1610                 break;
1611         case RELAYD_DATA_PENDING:
1612                 ret = relay_data_pending(recv_hdr, cmd, streams_ht);
1613                 break;
1614         case RELAYD_QUIESCENT_CONTROL:
1615                 ret = relay_quiescent_control(recv_hdr, cmd, streams_ht);
1616                 break;
1617         case RELAYD_BEGIN_DATA_PENDING:
1618                 ret = relay_begin_data_pending(recv_hdr, cmd, streams_ht);
1619                 break;
1620         case RELAYD_END_DATA_PENDING:
1621                 ret = relay_end_data_pending(recv_hdr, cmd, streams_ht);
1622                 break;
1623         case RELAYD_UPDATE_SYNC_INFO:
1624         default:
1625                 ERR("Received unknown command (%u)", be32toh(recv_hdr->cmd));
1626                 relay_unknown_command(cmd);
1627                 ret = -1;
1628                 goto end;
1629         }
1630
1631 end:
1632         return ret;
1633 }
1634
1635 /*
1636  * relay_process_data: Process the data received on the data socket
1637  */
1638 static
1639 int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
1640 {
1641         int ret = 0;
1642         struct relay_stream *stream;
1643         struct lttcomm_relayd_data_hdr data_hdr;
1644         uint64_t stream_id;
1645         uint64_t net_seq_num;
1646         uint32_t data_size;
1647
1648         ret = cmd->sock->ops->recvmsg(cmd->sock, &data_hdr,
1649                         sizeof(struct lttcomm_relayd_data_hdr), 0);
1650         if (ret <= 0) {
1651                 if (ret == 0) {
1652                         /* Orderly shutdown. Not necessary to print an error. */
1653                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1654                 } else {
1655                         ERR("Unable to receive data header on sock %d", cmd->sock->fd);
1656                 }
1657                 ret = -1;
1658                 goto end;
1659         }
1660
1661         stream_id = be64toh(data_hdr.stream_id);
1662
1663         rcu_read_lock();
1664         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1665         if (!stream) {
1666                 ret = -1;
1667                 goto end_unlock;
1668         }
1669
1670         data_size = be32toh(data_hdr.data_size);
1671         if (data_buffer_size < data_size) {
1672                 char *tmp_data_ptr;
1673
1674                 tmp_data_ptr = realloc(data_buffer, data_size);
1675                 if (!tmp_data_ptr) {
1676                         ERR("Allocating data buffer");
1677                         free(data_buffer);
1678                         ret = -1;
1679                         goto end_unlock;
1680                 }
1681                 data_buffer = tmp_data_ptr;
1682                 data_buffer_size = data_size;
1683         }
1684         memset(data_buffer, 0, data_size);
1685
1686         net_seq_num = be64toh(data_hdr.net_seq_num);
1687
1688         DBG3("Receiving data of size %u for stream id %" PRIu64 " seqnum %" PRIu64,
1689                 data_size, stream_id, net_seq_num);
1690         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1691         if (ret <= 0) {
1692                 if (ret == 0) {
1693                         /* Orderly shutdown. Not necessary to print an error. */
1694                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1695                 }
1696                 ret = -1;
1697                 goto end_unlock;
1698         }
1699
1700         do {
1701                 ret = write(stream->fd, data_buffer, data_size);
1702         } while (ret < 0 && errno == EINTR);
1703         if (ret < 0 || ret != data_size) {
1704                 ERR("Relay error writing data to file");
1705                 ret = -1;
1706                 goto end_unlock;
1707         }
1708
1709         DBG2("Relay wrote %d bytes to tracefile for stream id %" PRIu64,
1710                         ret, stream->stream_handle);
1711
1712         ret = write_padding_to_file(stream->fd, be32toh(data_hdr.padding_size));
1713         if (ret < 0) {
1714                 goto end_unlock;
1715         }
1716
1717         stream->prev_seq = net_seq_num;
1718
1719         /* Check if we need to close the FD */
1720         if (close_stream_check(stream)) {
1721                 int cret;
1722                 struct lttng_ht_iter iter;
1723
1724                 cret = close(stream->fd);
1725                 if (cret < 0) {
1726                         PERROR("close stream process data");
1727                 }
1728                 iter.iter.node = &stream->stream_n.node;
1729                 ret = lttng_ht_del(streams_ht, &iter);
1730                 assert(!ret);
1731                 call_rcu(&stream->rcu_node,
1732                         deferred_free_stream);
1733                 DBG("Closed tracefile %d after recv data", stream->fd);
1734         }
1735
1736 end_unlock:
1737         rcu_read_unlock();
1738 end:
1739         return ret;
1740 }
1741
1742 static
1743 void relay_cleanup_poll_connection(struct lttng_poll_event *events, int pollfd)
1744 {
1745         int ret;
1746
1747         lttng_poll_del(events, pollfd);
1748
1749         ret = close(pollfd);
1750         if (ret < 0) {
1751                 ERR("Closing pollfd %d", pollfd);
1752         }
1753 }
1754
1755 static
1756 int relay_add_connection(int fd, struct lttng_poll_event *events,
1757                 struct lttng_ht *relay_connections_ht)
1758 {
1759         struct relay_command *relay_connection;
1760         int ret;
1761
1762         relay_connection = zmalloc(sizeof(struct relay_command));
1763         if (relay_connection == NULL) {
1764                 PERROR("Relay command zmalloc");
1765                 goto error;
1766         }
1767         do {
1768                 ret = read(fd, relay_connection, sizeof(struct relay_command));
1769         } while (ret < 0 && errno == EINTR);
1770         if (ret < 0 || ret < sizeof(struct relay_command)) {
1771                 PERROR("read relay cmd pipe");
1772                 goto error_read;
1773         }
1774
1775         lttng_ht_node_init_ulong(&relay_connection->sock_n,
1776                         (unsigned long) relay_connection->sock->fd);
1777         rcu_read_lock();
1778         lttng_ht_add_unique_ulong(relay_connections_ht,
1779                         &relay_connection->sock_n);
1780         rcu_read_unlock();
1781         return lttng_poll_add(events,
1782                         relay_connection->sock->fd,
1783                         LPOLLIN | LPOLLRDHUP);
1784
1785 error_read:
1786         free(relay_connection);
1787 error:
1788         return -1;
1789 }
1790
1791 static
1792 void deferred_free_connection(struct rcu_head *head)
1793 {
1794         struct relay_command *relay_connection =
1795                 caa_container_of(head, struct relay_command, rcu_node);
1796
1797         lttcomm_destroy_sock(relay_connection->sock);
1798         free(relay_connection);
1799 }
1800
1801 static
1802 void relay_del_connection(struct lttng_ht *relay_connections_ht,
1803                 struct lttng_ht *streams_ht, struct lttng_ht_iter *iter,
1804                 struct relay_command *relay_connection)
1805 {
1806         int ret;
1807
1808         ret = lttng_ht_del(relay_connections_ht, iter);
1809         assert(!ret);
1810         if (relay_connection->type == RELAY_CONTROL) {
1811                 relay_delete_session(relay_connection, streams_ht);
1812         }
1813
1814         call_rcu(&relay_connection->rcu_node,
1815                 deferred_free_connection);
1816 }
1817
1818 /*
1819  * This thread does the actual work
1820  */
1821 static
1822 void *relay_thread_worker(void *data)
1823 {
1824         int ret, err = -1, last_seen_data_fd = -1;
1825         uint32_t nb_fd;
1826         struct relay_command *relay_connection;
1827         struct lttng_poll_event events;
1828         struct lttng_ht *relay_connections_ht;
1829         struct lttng_ht_node_ulong *node;
1830         struct lttng_ht_iter iter;
1831         struct lttng_ht *streams_ht;
1832         struct lttcomm_relayd_hdr recv_hdr;
1833
1834         DBG("[thread] Relay worker started");
1835
1836         rcu_register_thread();
1837
1838         /* table of connections indexed on socket */
1839         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1840         if (!relay_connections_ht) {
1841                 goto relay_connections_ht_error;
1842         }
1843
1844         /* tables of streams indexed by stream ID */
1845         streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1846         if (!streams_ht) {
1847                 goto streams_ht_error;
1848         }
1849
1850         ret = create_thread_poll_set(&events, 2);
1851         if (ret < 0) {
1852                 goto error_poll_create;
1853         }
1854
1855         ret = lttng_poll_add(&events, relay_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1856         if (ret < 0) {
1857                 goto error;
1858         }
1859
1860 restart:
1861         while (1) {
1862                 int idx = -1, i, seen_control = 0, last_notdel_data_fd = -1;
1863
1864                 /* Infinite blocking call, waiting for transmission */
1865                 DBG3("Relayd worker thread polling...");
1866                 ret = lttng_poll_wait(&events, -1);
1867                 if (ret < 0) {
1868                         /*
1869                          * Restart interrupted system call.
1870                          */
1871                         if (errno == EINTR) {
1872                                 goto restart;
1873                         }
1874                         goto error;
1875                 }
1876
1877                 nb_fd = ret;
1878
1879                 /*
1880                  * Process control. The control connection is prioritised so we don't
1881                  * starve it with high throughout put tracing data on the data
1882                  * connection.
1883                  */
1884                 for (i = 0; i < nb_fd; i++) {
1885                         /* Fetch once the poll data */
1886                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
1887                         int pollfd = LTTNG_POLL_GETFD(&events, i);
1888
1889                         /* Thread quit pipe has been closed. Killing thread. */
1890                         ret = check_thread_quit_pipe(pollfd, revents);
1891                         if (ret) {
1892                                 err = 0;
1893                                 goto exit;
1894                         }
1895
1896                         /* Inspect the relay cmd pipe for new connection */
1897                         if (pollfd == relay_cmd_pipe[0]) {
1898                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1899                                         ERR("Relay pipe error");
1900                                         goto error;
1901                                 } else if (revents & LPOLLIN) {
1902                                         DBG("Relay command received");
1903                                         ret = relay_add_connection(relay_cmd_pipe[0],
1904                                                         &events, relay_connections_ht);
1905                                         if (ret < 0) {
1906                                                 goto error;
1907                                         }
1908                                 }
1909                         } else if (revents) {
1910                                 rcu_read_lock();
1911                                 lttng_ht_lookup(relay_connections_ht,
1912                                                 (void *)((unsigned long) pollfd),
1913                                                 &iter);
1914                                 node = lttng_ht_iter_get_node_ulong(&iter);
1915                                 if (node == NULL) {
1916                                         DBG2("Relay sock %d not found", pollfd);
1917                                         rcu_read_unlock();
1918                                         goto error;
1919                                 }
1920                                 relay_connection = caa_container_of(node,
1921                                                 struct relay_command, sock_n);
1922
1923                                 if (revents & (LPOLLERR)) {
1924                                         ERR("POLL ERROR");
1925                                         relay_cleanup_poll_connection(&events, pollfd);
1926                                         relay_del_connection(relay_connections_ht,
1927                                                         streams_ht, &iter,
1928                                                         relay_connection);
1929                                         if (last_seen_data_fd == pollfd) {
1930                                                 last_seen_data_fd = last_notdel_data_fd;
1931                                         }
1932                                 } else if (revents & (LPOLLHUP | LPOLLRDHUP)) {
1933                                         DBG("Socket %d hung up", pollfd);
1934                                         relay_cleanup_poll_connection(&events, pollfd);
1935                                         relay_del_connection(relay_connections_ht,
1936                                                         streams_ht, &iter,
1937                                                         relay_connection);
1938                                         if (last_seen_data_fd == pollfd) {
1939                                                 last_seen_data_fd = last_notdel_data_fd;
1940                                         }
1941                                 } else if (revents & LPOLLIN) {
1942                                         /* control socket */
1943                                         if (relay_connection->type == RELAY_CONTROL) {
1944                                                 ret = relay_connection->sock->ops->recvmsg(
1945                                                                 relay_connection->sock, &recv_hdr,
1946                                                                 sizeof(struct lttcomm_relayd_hdr), 0);
1947                                                 /* connection closed */
1948                                                 if (ret <= 0) {
1949                                                         relay_cleanup_poll_connection(&events, pollfd);
1950                                                         relay_del_connection(relay_connections_ht,
1951                                                                         streams_ht, &iter,
1952                                                                         relay_connection);
1953                                                         DBG("Control connection closed with %d", pollfd);
1954                                                 } else {
1955                                                         if (relay_connection->session) {
1956                                                                 DBG2("Relay worker receiving data for session : %" PRIu64,
1957                                                                                 relay_connection->session->id);
1958                                                         }
1959                                                         ret = relay_process_control(&recv_hdr,
1960                                                                         relay_connection,
1961                                                                         streams_ht);
1962                                                         if (ret < 0) {
1963                                                                 /* Clear the session on error. */
1964                                                                 relay_cleanup_poll_connection(&events, pollfd);
1965                                                                 relay_del_connection(relay_connections_ht,
1966                                                                                 streams_ht, &iter,
1967                                                                                 relay_connection);
1968                                                                 DBG("Connection closed with %d", pollfd);
1969                                                         }
1970                                                         seen_control = 1;
1971                                                 }
1972                                         } else {
1973                                                 /*
1974                                                  * Flag the last seen data fd not deleted. It will be
1975                                                  * used as the last seen fd if any fd gets deleted in
1976                                                  * this first loop.
1977                                                  */
1978                                                 last_notdel_data_fd = pollfd;
1979                                         }
1980                                 }
1981                                 rcu_read_unlock();
1982                         }
1983                 }
1984
1985                 /*
1986                  * The last loop handled a control request, go back to poll to make
1987                  * sure we prioritise the control socket.
1988                  */
1989                 if (seen_control) {
1990                         continue;
1991                 }
1992
1993                 if (last_seen_data_fd >= 0) {
1994                         for (i = 0; i < nb_fd; i++) {
1995                                 int pollfd = LTTNG_POLL_GETFD(&events, i);
1996                                 if (last_seen_data_fd == pollfd) {
1997                                         idx = i;
1998                                         break;
1999                                 }
2000                         }
2001                 }
2002
2003                 /* Process data connection. */
2004                 for (i = idx + 1; i < nb_fd; i++) {
2005                         /* Fetch the poll data. */
2006                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
2007                         int pollfd = LTTNG_POLL_GETFD(&events, i);
2008
2009                         /* Skip the command pipe. It's handled in the first loop. */
2010                         if (pollfd == relay_cmd_pipe[0]) {
2011                                 continue;
2012                         }
2013
2014                         if (revents) {
2015                                 rcu_read_lock();
2016                                 lttng_ht_lookup(relay_connections_ht,
2017                                                 (void *)((unsigned long) pollfd),
2018                                                 &iter);
2019                                 node = lttng_ht_iter_get_node_ulong(&iter);
2020                                 if (node == NULL) {
2021                                         /* Skip it. Might be removed before. */
2022                                         rcu_read_unlock();
2023                                         continue;
2024                                 }
2025                                 relay_connection = caa_container_of(node,
2026                                                 struct relay_command, sock_n);
2027
2028                                 if (revents & LPOLLIN) {
2029                                         if (relay_connection->type != RELAY_DATA) {
2030                                                 continue;
2031                                         }
2032
2033                                         ret = relay_process_data(relay_connection, streams_ht);
2034                                         /* connection closed */
2035                                         if (ret < 0) {
2036                                                 relay_cleanup_poll_connection(&events, pollfd);
2037                                                 relay_del_connection(relay_connections_ht,
2038                                                                 streams_ht, &iter,
2039                                                                 relay_connection);
2040                                                 DBG("Data connection closed with %d", pollfd);
2041                                                 /*
2042                                                  * Every goto restart call sets the last seen fd where
2043                                                  * here we don't really care since we gracefully
2044                                                  * continue the loop after the connection is deleted.
2045                                                  */
2046                                         } else {
2047                                                 /* Keep last seen port. */
2048                                                 last_seen_data_fd = pollfd;
2049                                                 rcu_read_unlock();
2050                                                 goto restart;
2051                                         }
2052                                 }
2053                                 rcu_read_unlock();
2054                         }
2055                 }
2056                 last_seen_data_fd = -1;
2057         }
2058
2059 exit:
2060 error:
2061         lttng_poll_clean(&events);
2062
2063         /* empty the hash table and free the memory */
2064         rcu_read_lock();
2065         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter, node, node) {
2066                 node = lttng_ht_iter_get_node_ulong(&iter);
2067                 if (node) {
2068                         relay_connection = caa_container_of(node,
2069                                         struct relay_command, sock_n);
2070                         relay_del_connection(relay_connections_ht,
2071                                         streams_ht, &iter,
2072                                         relay_connection);
2073                 }
2074         }
2075         rcu_read_unlock();
2076 error_poll_create:
2077         lttng_ht_destroy(streams_ht);
2078 streams_ht_error:
2079         lttng_ht_destroy(relay_connections_ht);
2080 relay_connections_ht_error:
2081         /* Close relay cmd pipes */
2082         utils_close_pipe(relay_cmd_pipe);
2083         if (err) {
2084                 DBG("Thread exited with error");
2085         }
2086         DBG("Worker thread cleanup complete");
2087         free(data_buffer);
2088         stop_threads();
2089         rcu_unregister_thread();
2090         return NULL;
2091 }
2092
2093 /*
2094  * Create the relay command pipe to wake thread_manage_apps.
2095  * Closed in cleanup().
2096  */
2097 static int create_relay_cmd_pipe(void)
2098 {
2099         int ret;
2100
2101         ret = utils_create_pipe_cloexec(relay_cmd_pipe);
2102
2103         return ret;
2104 }
2105
2106 /*
2107  * main
2108  */
2109 int main(int argc, char **argv)
2110 {
2111         int ret = 0;
2112         void *status;
2113
2114         /* Create thread quit pipe */
2115         if ((ret = init_thread_quit_pipe()) < 0) {
2116                 goto error;
2117         }
2118
2119         /* Parse arguments */
2120         progname = argv[0];
2121         if ((ret = parse_args(argc, argv)) < 0) {
2122                 goto exit;
2123         }
2124
2125         if ((ret = set_signal_handler()) < 0) {
2126                 goto exit;
2127         }
2128
2129         /* Try to create directory if -o, --output is specified. */
2130         if (opt_output_path) {
2131                 ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG);
2132                 if (ret < 0) {
2133                         ERR("Unable to create %s", opt_output_path);
2134                         goto exit;
2135                 }
2136         }
2137
2138         /* Daemonize */
2139         if (opt_daemon) {
2140                 ret = daemon(0, 0);
2141                 if (ret < 0) {
2142                         PERROR("daemon");
2143                         goto exit;
2144                 }
2145         }
2146
2147         /* Check if daemon is UID = 0 */
2148         is_root = !getuid();
2149
2150         if (!is_root) {
2151                 if (control_uri->port < 1024 || data_uri->port < 1024) {
2152                         ERR("Need to be root to use ports < 1024");
2153                         ret = -1;
2154                         goto exit;
2155                 }
2156         }
2157
2158         /* Setup the thread apps communication pipe. */
2159         if ((ret = create_relay_cmd_pipe()) < 0) {
2160                 goto exit;
2161         }
2162
2163         /* Init relay command queue. */
2164         cds_wfq_init(&relay_cmd_queue.queue);
2165
2166         /* Set up max poll set size */
2167         lttng_poll_set_max_size();
2168
2169         /* Setup the dispatcher thread */
2170         ret = pthread_create(&dispatcher_thread, NULL,
2171                         relay_thread_dispatcher, (void *) NULL);
2172         if (ret != 0) {
2173                 PERROR("pthread_create dispatcher");
2174                 goto exit_dispatcher;
2175         }
2176
2177         /* Setup the worker thread */
2178         ret = pthread_create(&worker_thread, NULL,
2179                         relay_thread_worker, (void *) NULL);
2180         if (ret != 0) {
2181                 PERROR("pthread_create worker");
2182                 goto exit_worker;
2183         }
2184
2185         /* Setup the listener thread */
2186         ret = pthread_create(&listener_thread, NULL,
2187                         relay_thread_listener, (void *) NULL);
2188         if (ret != 0) {
2189                 PERROR("pthread_create listener");
2190                 goto exit_listener;
2191         }
2192
2193 exit_listener:
2194         ret = pthread_join(listener_thread, &status);
2195         if (ret != 0) {
2196                 PERROR("pthread_join");
2197                 goto error;     /* join error, exit without cleanup */
2198         }
2199
2200 exit_worker:
2201         ret = pthread_join(worker_thread, &status);
2202         if (ret != 0) {
2203                 PERROR("pthread_join");
2204                 goto error;     /* join error, exit without cleanup */
2205         }
2206
2207 exit_dispatcher:
2208         ret = pthread_join(dispatcher_thread, &status);
2209         if (ret != 0) {
2210                 PERROR("pthread_join");
2211                 goto error;     /* join error, exit without cleanup */
2212         }
2213
2214 exit:
2215         cleanup();
2216         if (!ret) {
2217                 exit(EXIT_SUCCESS);
2218         }
2219
2220 error:
2221         exit(EXIT_FAILURE);
2222 }