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)
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         /*
1266          * For now, we just ignore the received version but after 2.1 stable
1267          * release, a check must be done to see if we either adapt to the other
1268          * side version (which MUST be lower than us) or keep the latest data
1269          * structure considering that the other side will adapt.
1270          */
1271
1272         ret = sscanf(VERSION, "%10u.%10u", &reply.major, &reply.minor);
1273         if (ret < 2) {
1274                 ERR("Error in scanning version");
1275                 ret = -1;
1276                 goto end;
1277         }
1278         reply.major = htobe32(reply.major);
1279         reply.minor = htobe32(reply.minor);
1280         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1281                         sizeof(struct lttcomm_relayd_version), 0);
1282         if (ret < 0) {
1283                 ERR("Relay sending version");
1284         }
1285         DBG("Version check done (%u.%u)", be32toh(reply.major),
1286                         be32toh(reply.minor));
1287
1288 end:
1289         return ret;
1290 }
1291
1292 /*
1293  * Check for data pending for a given stream id from the session daemon.
1294  */
1295 static
1296 int relay_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1297                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1298 {
1299         struct relay_session *session = cmd->session;
1300         struct lttcomm_relayd_data_pending msg;
1301         struct lttcomm_relayd_generic_reply reply;
1302         struct relay_stream *stream;
1303         int ret;
1304         uint64_t last_net_seq_num, stream_id;
1305
1306         DBG("Data pending command received");
1307
1308         if (!session || cmd->version_check_done == 0) {
1309                 ERR("Trying to check for data before version check");
1310                 ret = -1;
1311                 goto end_no_session;
1312         }
1313
1314         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1315         if (ret < sizeof(msg)) {
1316                 if (ret == 0) {
1317                         /* Orderly shutdown. Not necessary to print an error. */
1318                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1319                 } else {
1320                         ERR("Relay didn't receive valid data_pending struct size : %d",
1321                                         ret);
1322                 }
1323                 ret = -1;
1324                 goto end_no_session;
1325         }
1326
1327         stream_id = be64toh(msg.stream_id);
1328         last_net_seq_num = be64toh(msg.last_net_seq_num);
1329
1330         rcu_read_lock();
1331         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1332         if (stream == NULL) {
1333                 ret = -1;
1334                 goto end_unlock;
1335         }
1336
1337         DBG("Data pending for stream id %" PRIu64 " prev_seq %" PRIu64
1338                         " and last_seq %" PRIu64, stream_id, stream->prev_seq,
1339                         last_net_seq_num);
1340
1341         /* Avoid wrapping issue */
1342         if (((int64_t) (stream->prev_seq - last_net_seq_num)) >= 0) {
1343                 /* Data has in fact been written and is NOT pending */
1344                 ret = 0;
1345         } else {
1346                 /* Data still being streamed thus pending */
1347                 ret = 1;
1348         }
1349
1350         /* Pending check is now done. */
1351         stream->data_pending_check_done = 1;
1352
1353 end_unlock:
1354         rcu_read_unlock();
1355
1356         reply.ret_code = htobe32(ret);
1357         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1358         if (ret < 0) {
1359                 ERR("Relay data pending ret code failed");
1360         }
1361
1362 end_no_session:
1363         return ret;
1364 }
1365
1366 /*
1367  * Wait for the control socket to reach a quiescent state.
1368  *
1369  * Note that for now, when receiving this command from the session daemon, this
1370  * means that every subsequent commands or data received on the control socket
1371  * has been handled. So, this is why we simply return OK here.
1372  */
1373 static
1374 int relay_quiescent_control(struct lttcomm_relayd_hdr *recv_hdr,
1375                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1376 {
1377         int ret;
1378         uint64_t stream_id;
1379         struct relay_stream *stream;
1380         struct lttng_ht_iter iter;
1381         struct lttcomm_relayd_quiescent_control msg;
1382         struct lttcomm_relayd_generic_reply reply;
1383
1384         DBG("Checking quiescent state on control socket");
1385
1386         if (!cmd->session || cmd->version_check_done == 0) {
1387                 ERR("Trying to check for data before version check");
1388                 ret = -1;
1389                 goto end_no_session;
1390         }
1391
1392         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1393         if (ret < sizeof(msg)) {
1394                 if (ret == 0) {
1395                         /* Orderly shutdown. Not necessary to print an error. */
1396                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1397                 } else {
1398                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1399                                         ret);
1400                 }
1401                 ret = -1;
1402                 goto end_no_session;
1403         }
1404
1405         stream_id = be64toh(msg.stream_id);
1406
1407         rcu_read_lock();
1408         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1409                 if (stream->stream_handle == stream_id) {
1410                         stream->data_pending_check_done = 1;
1411                         DBG("Relay quiescent control pending flag set to %" PRIu64,
1412                                         stream_id);
1413                         break;
1414                 }
1415         }
1416         rcu_read_unlock();
1417
1418         reply.ret_code = htobe32(LTTNG_OK);
1419         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1420         if (ret < 0) {
1421                 ERR("Relay data quiescent control ret code failed");
1422         }
1423
1424 end_no_session:
1425         return ret;
1426 }
1427
1428 /*
1429  * Initialize a data pending command. This means that a client is about to ask
1430  * for data pending for each stream he/she holds. Simply iterate over all
1431  * streams of a session and set the data_pending_check_done flag.
1432  *
1433  * This command returns to the client a LTTNG_OK code.
1434  */
1435 static
1436 int relay_begin_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1437                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1438 {
1439         int ret;
1440         struct lttng_ht_iter iter;
1441         struct lttcomm_relayd_begin_data_pending msg;
1442         struct lttcomm_relayd_generic_reply reply;
1443         struct relay_stream *stream;
1444         uint64_t session_id;
1445
1446         assert(recv_hdr);
1447         assert(cmd);
1448         assert(streams_ht);
1449
1450         DBG("Init streams for data pending");
1451
1452         if (!cmd->session || cmd->version_check_done == 0) {
1453                 ERR("Trying to check for data before version check");
1454                 ret = -1;
1455                 goto end_no_session;
1456         }
1457
1458         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1459         if (ret < sizeof(msg)) {
1460                 if (ret == 0) {
1461                         /* Orderly shutdown. Not necessary to print an error. */
1462                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1463                 } else {
1464                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1465                                         ret);
1466                 }
1467                 ret = -1;
1468                 goto end_no_session;
1469         }
1470
1471         session_id = be64toh(msg.session_id);
1472
1473         /*
1474          * Iterate over all streams to set the begin data pending flag. For now, the
1475          * streams are indexed by stream handle so we have to iterate over all
1476          * streams to find the one associated with the right session_id.
1477          */
1478         rcu_read_lock();
1479         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1480                 if (stream->session->id == session_id) {
1481                         stream->data_pending_check_done = 0;
1482                         DBG("Set begin data pending flag to stream %" PRIu64,
1483                                         stream->stream_handle);
1484                 }
1485         }
1486         rcu_read_unlock();
1487
1488         /* All good, send back reply. */
1489         reply.ret_code = htobe32(LTTNG_OK);
1490
1491         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1492         if (ret < 0) {
1493                 ERR("Relay begin data pending send reply failed");
1494         }
1495
1496 end_no_session:
1497         return ret;
1498 }
1499
1500 /*
1501  * End data pending command. This will check, for a given session id, if each
1502  * stream associated with it has its data_pending_check_done flag set. If not,
1503  * this means that the client lost track of the stream but the data is still
1504  * being streamed on our side. In this case, we inform the client that data is
1505  * inflight.
1506  *
1507  * Return to the client if there is data in flight or not with a ret_code.
1508  */
1509 static
1510 int relay_end_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1511                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1512 {
1513         int ret;
1514         struct lttng_ht_iter iter;
1515         struct lttcomm_relayd_end_data_pending msg;
1516         struct lttcomm_relayd_generic_reply reply;
1517         struct relay_stream *stream;
1518         uint64_t session_id;
1519         uint32_t is_data_inflight = 0;
1520
1521         assert(recv_hdr);
1522         assert(cmd);
1523         assert(streams_ht);
1524
1525         DBG("End data pending command");
1526
1527         if (!cmd->session || cmd->version_check_done == 0) {
1528                 ERR("Trying to check for data before version check");
1529                 ret = -1;
1530                 goto end_no_session;
1531         }
1532
1533         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1534         if (ret < sizeof(msg)) {
1535                 if (ret == 0) {
1536                         /* Orderly shutdown. Not necessary to print an error. */
1537                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1538                 } else {
1539                         ERR("Relay didn't receive valid end data_pending struct size: %d",
1540                                         ret);
1541                 }
1542                 ret = -1;
1543                 goto end_no_session;
1544         }
1545
1546         session_id = be64toh(msg.session_id);
1547
1548         /* Iterate over all streams to see if the begin data pending flag is set. */
1549         rcu_read_lock();
1550         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1551                 if (stream->session->id == session_id &&
1552                                 !stream->data_pending_check_done) {
1553                         is_data_inflight = 1;
1554                         DBG("Data is still in flight for stream %" PRIu64,
1555                                         stream->stream_handle);
1556                         break;
1557                 }
1558         }
1559         rcu_read_unlock();
1560
1561         /* All good, send back reply. */
1562         reply.ret_code = htobe32(is_data_inflight);
1563
1564         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1565         if (ret < 0) {
1566                 ERR("Relay end data pending send reply failed");
1567         }
1568
1569 end_no_session:
1570         return ret;
1571 }
1572
1573 /*
1574  * relay_process_control: Process the commands received on the control socket
1575  */
1576 static
1577 int relay_process_control(struct lttcomm_relayd_hdr *recv_hdr,
1578                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1579 {
1580         int ret = 0;
1581
1582         switch (be32toh(recv_hdr->cmd)) {
1583         case RELAYD_CREATE_SESSION:
1584                 ret = relay_create_session(recv_hdr, cmd);
1585                 break;
1586         case RELAYD_ADD_STREAM:
1587                 ret = relay_add_stream(recv_hdr, cmd, streams_ht);
1588                 break;
1589         case RELAYD_START_DATA:
1590                 ret = relay_start(recv_hdr, cmd);
1591                 break;
1592         case RELAYD_SEND_METADATA:
1593                 ret = relay_recv_metadata(recv_hdr, cmd, streams_ht);
1594                 break;
1595         case RELAYD_VERSION:
1596                 ret = relay_send_version(recv_hdr, cmd);
1597                 break;
1598         case RELAYD_CLOSE_STREAM:
1599                 ret = relay_close_stream(recv_hdr, cmd, streams_ht);
1600                 break;
1601         case RELAYD_DATA_PENDING:
1602                 ret = relay_data_pending(recv_hdr, cmd, streams_ht);
1603                 break;
1604         case RELAYD_QUIESCENT_CONTROL:
1605                 ret = relay_quiescent_control(recv_hdr, cmd, streams_ht);
1606                 break;
1607         case RELAYD_BEGIN_DATA_PENDING:
1608                 ret = relay_begin_data_pending(recv_hdr, cmd, streams_ht);
1609                 break;
1610         case RELAYD_END_DATA_PENDING:
1611                 ret = relay_end_data_pending(recv_hdr, cmd, streams_ht);
1612                 break;
1613         case RELAYD_UPDATE_SYNC_INFO:
1614         default:
1615                 ERR("Received unknown command (%u)", be32toh(recv_hdr->cmd));
1616                 relay_unknown_command(cmd);
1617                 ret = -1;
1618                 goto end;
1619         }
1620
1621 end:
1622         return ret;
1623 }
1624
1625 /*
1626  * relay_process_data: Process the data received on the data socket
1627  */
1628 static
1629 int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
1630 {
1631         int ret = 0;
1632         struct relay_stream *stream;
1633         struct lttcomm_relayd_data_hdr data_hdr;
1634         uint64_t stream_id;
1635         uint64_t net_seq_num;
1636         uint32_t data_size;
1637
1638         ret = cmd->sock->ops->recvmsg(cmd->sock, &data_hdr,
1639                         sizeof(struct lttcomm_relayd_data_hdr), 0);
1640         if (ret <= 0) {
1641                 if (ret == 0) {
1642                         /* Orderly shutdown. Not necessary to print an error. */
1643                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1644                 } else {
1645                         ERR("Unable to receive data header on sock %d", cmd->sock->fd);
1646                 }
1647                 ret = -1;
1648                 goto end;
1649         }
1650
1651         stream_id = be64toh(data_hdr.stream_id);
1652
1653         rcu_read_lock();
1654         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1655         if (!stream) {
1656                 ret = -1;
1657                 goto end_unlock;
1658         }
1659
1660         data_size = be32toh(data_hdr.data_size);
1661         if (data_buffer_size < data_size) {
1662                 char *tmp_data_ptr;
1663
1664                 tmp_data_ptr = realloc(data_buffer, data_size);
1665                 if (!tmp_data_ptr) {
1666                         ERR("Allocating data buffer");
1667                         free(data_buffer);
1668                         ret = -1;
1669                         goto end_unlock;
1670                 }
1671                 data_buffer = tmp_data_ptr;
1672                 data_buffer_size = data_size;
1673         }
1674         memset(data_buffer, 0, data_size);
1675
1676         net_seq_num = be64toh(data_hdr.net_seq_num);
1677
1678         DBG3("Receiving data of size %u for stream id %" PRIu64 " seqnum %" PRIu64,
1679                 data_size, stream_id, net_seq_num);
1680         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1681         if (ret <= 0) {
1682                 if (ret == 0) {
1683                         /* Orderly shutdown. Not necessary to print an error. */
1684                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1685                 }
1686                 ret = -1;
1687                 goto end_unlock;
1688         }
1689
1690         do {
1691                 ret = write(stream->fd, data_buffer, data_size);
1692         } while (ret < 0 && errno == EINTR);
1693         if (ret < 0 || ret != data_size) {
1694                 ERR("Relay error writing data to file");
1695                 ret = -1;
1696                 goto end_unlock;
1697         }
1698
1699         DBG2("Relay wrote %d bytes to tracefile for stream id %" PRIu64,
1700                         ret, stream->stream_handle);
1701
1702         ret = write_padding_to_file(stream->fd, be32toh(data_hdr.padding_size));
1703         if (ret < 0) {
1704                 goto end_unlock;
1705         }
1706
1707         stream->prev_seq = net_seq_num;
1708
1709         /* Check if we need to close the FD */
1710         if (close_stream_check(stream)) {
1711                 int cret;
1712                 struct lttng_ht_iter iter;
1713
1714                 cret = close(stream->fd);
1715                 if (cret < 0) {
1716                         PERROR("close stream process data");
1717                 }
1718                 iter.iter.node = &stream->stream_n.node;
1719                 ret = lttng_ht_del(streams_ht, &iter);
1720                 assert(!ret);
1721                 call_rcu(&stream->rcu_node,
1722                         deferred_free_stream);
1723                 DBG("Closed tracefile %d after recv data", stream->fd);
1724         }
1725
1726 end_unlock:
1727         rcu_read_unlock();
1728 end:
1729         return ret;
1730 }
1731
1732 static
1733 void relay_cleanup_poll_connection(struct lttng_poll_event *events, int pollfd)
1734 {
1735         int ret;
1736
1737         lttng_poll_del(events, pollfd);
1738
1739         ret = close(pollfd);
1740         if (ret < 0) {
1741                 ERR("Closing pollfd %d", pollfd);
1742         }
1743 }
1744
1745 static
1746 int relay_add_connection(int fd, struct lttng_poll_event *events,
1747                 struct lttng_ht *relay_connections_ht)
1748 {
1749         struct relay_command *relay_connection;
1750         int ret;
1751
1752         relay_connection = zmalloc(sizeof(struct relay_command));
1753         if (relay_connection == NULL) {
1754                 PERROR("Relay command zmalloc");
1755                 goto error;
1756         }
1757         do {
1758                 ret = read(fd, relay_connection, sizeof(struct relay_command));
1759         } while (ret < 0 && errno == EINTR);
1760         if (ret < 0 || ret < sizeof(struct relay_command)) {
1761                 PERROR("read relay cmd pipe");
1762                 goto error_read;
1763         }
1764
1765         lttng_ht_node_init_ulong(&relay_connection->sock_n,
1766                         (unsigned long) relay_connection->sock->fd);
1767         rcu_read_lock();
1768         lttng_ht_add_unique_ulong(relay_connections_ht,
1769                         &relay_connection->sock_n);
1770         rcu_read_unlock();
1771         return lttng_poll_add(events,
1772                         relay_connection->sock->fd,
1773                         LPOLLIN | LPOLLRDHUP);
1774
1775 error_read:
1776         free(relay_connection);
1777 error:
1778         return -1;
1779 }
1780
1781 static
1782 void deferred_free_connection(struct rcu_head *head)
1783 {
1784         struct relay_command *relay_connection =
1785                 caa_container_of(head, struct relay_command, rcu_node);
1786
1787         lttcomm_destroy_sock(relay_connection->sock);
1788         free(relay_connection);
1789 }
1790
1791 static
1792 void relay_del_connection(struct lttng_ht *relay_connections_ht,
1793                 struct lttng_ht *streams_ht, struct lttng_ht_iter *iter,
1794                 struct relay_command *relay_connection)
1795 {
1796         int ret;
1797
1798         ret = lttng_ht_del(relay_connections_ht, iter);
1799         assert(!ret);
1800         if (relay_connection->type == RELAY_CONTROL) {
1801                 relay_delete_session(relay_connection, streams_ht);
1802         }
1803
1804         call_rcu(&relay_connection->rcu_node,
1805                 deferred_free_connection);
1806 }
1807
1808 /*
1809  * This thread does the actual work
1810  */
1811 static
1812 void *relay_thread_worker(void *data)
1813 {
1814         int ret, err = -1, last_seen_data_fd = -1;
1815         uint32_t nb_fd;
1816         struct relay_command *relay_connection;
1817         struct lttng_poll_event events;
1818         struct lttng_ht *relay_connections_ht;
1819         struct lttng_ht_node_ulong *node;
1820         struct lttng_ht_iter iter;
1821         struct lttng_ht *streams_ht;
1822         struct lttcomm_relayd_hdr recv_hdr;
1823
1824         DBG("[thread] Relay worker started");
1825
1826         rcu_register_thread();
1827
1828         /* table of connections indexed on socket */
1829         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1830         if (!relay_connections_ht) {
1831                 goto relay_connections_ht_error;
1832         }
1833
1834         /* tables of streams indexed by stream ID */
1835         streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1836         if (!streams_ht) {
1837                 goto streams_ht_error;
1838         }
1839
1840         ret = create_thread_poll_set(&events, 2);
1841         if (ret < 0) {
1842                 goto error_poll_create;
1843         }
1844
1845         ret = lttng_poll_add(&events, relay_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1846         if (ret < 0) {
1847                 goto error;
1848         }
1849
1850 restart:
1851         while (1) {
1852                 int idx = -1, i, seen_control = 0, last_notdel_data_fd = -1;
1853
1854                 /* Infinite blocking call, waiting for transmission */
1855                 DBG3("Relayd worker thread polling...");
1856                 ret = lttng_poll_wait(&events, -1);
1857                 if (ret < 0) {
1858                         /*
1859                          * Restart interrupted system call.
1860                          */
1861                         if (errno == EINTR) {
1862                                 goto restart;
1863                         }
1864                         goto error;
1865                 }
1866
1867                 nb_fd = ret;
1868
1869                 /*
1870                  * Process control. The control connection is prioritised so we don't
1871                  * starve it with high throughout put tracing data on the data
1872                  * connection.
1873                  */
1874                 for (i = 0; i < nb_fd; i++) {
1875                         /* Fetch once the poll data */
1876                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
1877                         int pollfd = LTTNG_POLL_GETFD(&events, i);
1878
1879                         /* Thread quit pipe has been closed. Killing thread. */
1880                         ret = check_thread_quit_pipe(pollfd, revents);
1881                         if (ret) {
1882                                 err = 0;
1883                                 goto exit;
1884                         }
1885
1886                         /* Inspect the relay cmd pipe for new connection */
1887                         if (pollfd == relay_cmd_pipe[0]) {
1888                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1889                                         ERR("Relay pipe error");
1890                                         goto error;
1891                                 } else if (revents & LPOLLIN) {
1892                                         DBG("Relay command received");
1893                                         ret = relay_add_connection(relay_cmd_pipe[0],
1894                                                         &events, relay_connections_ht);
1895                                         if (ret < 0) {
1896                                                 goto error;
1897                                         }
1898                                 }
1899                         } else if (revents) {
1900                                 rcu_read_lock();
1901                                 lttng_ht_lookup(relay_connections_ht,
1902                                                 (void *)((unsigned long) pollfd),
1903                                                 &iter);
1904                                 node = lttng_ht_iter_get_node_ulong(&iter);
1905                                 if (node == NULL) {
1906                                         DBG2("Relay sock %d not found", pollfd);
1907                                         rcu_read_unlock();
1908                                         goto error;
1909                                 }
1910                                 relay_connection = caa_container_of(node,
1911                                                 struct relay_command, sock_n);
1912
1913                                 if (revents & (LPOLLERR)) {
1914                                         ERR("POLL ERROR");
1915                                         relay_cleanup_poll_connection(&events, pollfd);
1916                                         relay_del_connection(relay_connections_ht,
1917                                                         streams_ht, &iter,
1918                                                         relay_connection);
1919                                         if (last_seen_data_fd == pollfd) {
1920                                                 last_seen_data_fd = last_notdel_data_fd;
1921                                         }
1922                                 } else if (revents & (LPOLLHUP | LPOLLRDHUP)) {
1923                                         DBG("Socket %d hung up", pollfd);
1924                                         relay_cleanup_poll_connection(&events, pollfd);
1925                                         relay_del_connection(relay_connections_ht,
1926                                                         streams_ht, &iter,
1927                                                         relay_connection);
1928                                         if (last_seen_data_fd == pollfd) {
1929                                                 last_seen_data_fd = last_notdel_data_fd;
1930                                         }
1931                                 } else if (revents & LPOLLIN) {
1932                                         /* control socket */
1933                                         if (relay_connection->type == RELAY_CONTROL) {
1934                                                 ret = relay_connection->sock->ops->recvmsg(
1935                                                                 relay_connection->sock, &recv_hdr,
1936                                                                 sizeof(struct lttcomm_relayd_hdr), 0);
1937                                                 /* connection closed */
1938                                                 if (ret <= 0) {
1939                                                         relay_cleanup_poll_connection(&events, pollfd);
1940                                                         relay_del_connection(relay_connections_ht,
1941                                                                         streams_ht, &iter,
1942                                                                         relay_connection);
1943                                                         DBG("Control connection closed with %d", pollfd);
1944                                                 } else {
1945                                                         if (relay_connection->session) {
1946                                                                 DBG2("Relay worker receiving data for session : %" PRIu64,
1947                                                                                 relay_connection->session->id);
1948                                                         }
1949                                                         ret = relay_process_control(&recv_hdr,
1950                                                                         relay_connection,
1951                                                                         streams_ht);
1952                                                         if (ret < 0) {
1953                                                                 /* Clear the session on error. */
1954                                                                 relay_cleanup_poll_connection(&events, pollfd);
1955                                                                 relay_del_connection(relay_connections_ht,
1956                                                                                 streams_ht, &iter,
1957                                                                                 relay_connection);
1958                                                                 DBG("Connection closed with %d", pollfd);
1959                                                         }
1960                                                         seen_control = 1;
1961                                                 }
1962                                         } else {
1963                                                 /*
1964                                                  * Flag the last seen data fd not deleted. It will be
1965                                                  * used as the last seen fd if any fd gets deleted in
1966                                                  * this first loop.
1967                                                  */
1968                                                 last_notdel_data_fd = pollfd;
1969                                         }
1970                                 }
1971                                 rcu_read_unlock();
1972                         }
1973                 }
1974
1975                 /*
1976                  * The last loop handled a control request, go back to poll to make
1977                  * sure we prioritise the control socket.
1978                  */
1979                 if (seen_control) {
1980                         continue;
1981                 }
1982
1983                 if (last_seen_data_fd >= 0) {
1984                         for (i = 0; i < nb_fd; i++) {
1985                                 int pollfd = LTTNG_POLL_GETFD(&events, i);
1986                                 if (last_seen_data_fd == pollfd) {
1987                                         idx = i;
1988                                         break;
1989                                 }
1990                         }
1991                 }
1992
1993                 /* Process data connection. */
1994                 for (i = idx + 1; i < nb_fd; i++) {
1995                         /* Fetch the poll data. */
1996                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
1997                         int pollfd = LTTNG_POLL_GETFD(&events, i);
1998
1999                         /* Skip the command pipe. It's handled in the first loop. */
2000                         if (pollfd == relay_cmd_pipe[0]) {
2001                                 continue;
2002                         }
2003
2004                         if (revents) {
2005                                 rcu_read_lock();
2006                                 lttng_ht_lookup(relay_connections_ht,
2007                                                 (void *)((unsigned long) pollfd),
2008                                                 &iter);
2009                                 node = lttng_ht_iter_get_node_ulong(&iter);
2010                                 if (node == NULL) {
2011                                         /* Skip it. Might be removed before. */
2012                                         rcu_read_unlock();
2013                                         continue;
2014                                 }
2015                                 relay_connection = caa_container_of(node,
2016                                                 struct relay_command, sock_n);
2017
2018                                 if (revents & LPOLLIN) {
2019                                         if (relay_connection->type != RELAY_DATA) {
2020                                                 continue;
2021                                         }
2022
2023                                         ret = relay_process_data(relay_connection, streams_ht);
2024                                         /* connection closed */
2025                                         if (ret < 0) {
2026                                                 relay_cleanup_poll_connection(&events, pollfd);
2027                                                 relay_del_connection(relay_connections_ht,
2028                                                                 streams_ht, &iter,
2029                                                                 relay_connection);
2030                                                 DBG("Data connection closed with %d", pollfd);
2031                                                 /*
2032                                                  * Every goto restart call sets the last seen fd where
2033                                                  * here we don't really care since we gracefully
2034                                                  * continue the loop after the connection is deleted.
2035                                                  */
2036                                         } else {
2037                                                 /* Keep last seen port. */
2038                                                 last_seen_data_fd = pollfd;
2039                                                 rcu_read_unlock();
2040                                                 goto restart;
2041                                         }
2042                                 }
2043                                 rcu_read_unlock();
2044                         }
2045                 }
2046                 last_seen_data_fd = -1;
2047         }
2048
2049 exit:
2050 error:
2051         lttng_poll_clean(&events);
2052
2053         /* empty the hash table and free the memory */
2054         rcu_read_lock();
2055         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter, node, node) {
2056                 node = lttng_ht_iter_get_node_ulong(&iter);
2057                 if (node) {
2058                         relay_connection = caa_container_of(node,
2059                                         struct relay_command, sock_n);
2060                         relay_del_connection(relay_connections_ht,
2061                                         streams_ht, &iter,
2062                                         relay_connection);
2063                 }
2064         }
2065         rcu_read_unlock();
2066 error_poll_create:
2067         lttng_ht_destroy(streams_ht);
2068 streams_ht_error:
2069         lttng_ht_destroy(relay_connections_ht);
2070 relay_connections_ht_error:
2071         /* Close relay cmd pipes */
2072         utils_close_pipe(relay_cmd_pipe);
2073         if (err) {
2074                 DBG("Thread exited with error");
2075         }
2076         DBG("Worker thread cleanup complete");
2077         free(data_buffer);
2078         stop_threads();
2079         rcu_unregister_thread();
2080         return NULL;
2081 }
2082
2083 /*
2084  * Create the relay command pipe to wake thread_manage_apps.
2085  * Closed in cleanup().
2086  */
2087 static int create_relay_cmd_pipe(void)
2088 {
2089         int ret;
2090
2091         ret = utils_create_pipe_cloexec(relay_cmd_pipe);
2092
2093         return ret;
2094 }
2095
2096 /*
2097  * main
2098  */
2099 int main(int argc, char **argv)
2100 {
2101         int ret = 0;
2102         void *status;
2103
2104         /* Create thread quit pipe */
2105         if ((ret = init_thread_quit_pipe()) < 0) {
2106                 goto error;
2107         }
2108
2109         /* Parse arguments */
2110         progname = argv[0];
2111         if ((ret = parse_args(argc, argv)) < 0) {
2112                 goto exit;
2113         }
2114
2115         if ((ret = set_signal_handler()) < 0) {
2116                 goto exit;
2117         }
2118
2119         /* Try to create directory if -o, --output is specified. */
2120         if (opt_output_path) {
2121                 ret = utils_mkdir_recursive(opt_output_path, S_IRWXU | S_IRWXG);
2122                 if (ret < 0) {
2123                         ERR("Unable to create %s", opt_output_path);
2124                         goto exit;
2125                 }
2126         }
2127
2128         /* Daemonize */
2129         if (opt_daemon) {
2130                 ret = daemon(0, 0);
2131                 if (ret < 0) {
2132                         PERROR("daemon");
2133                         goto exit;
2134                 }
2135         }
2136
2137         /* Check if daemon is UID = 0 */
2138         is_root = !getuid();
2139
2140         if (!is_root) {
2141                 if (control_uri->port < 1024 || data_uri->port < 1024) {
2142                         ERR("Need to be root to use ports < 1024");
2143                         ret = -1;
2144                         goto exit;
2145                 }
2146         }
2147
2148         /* Setup the thread apps communication pipe. */
2149         if ((ret = create_relay_cmd_pipe()) < 0) {
2150                 goto exit;
2151         }
2152
2153         /* Init relay command queue. */
2154         cds_wfq_init(&relay_cmd_queue.queue);
2155
2156         /* Set up max poll set size */
2157         lttng_poll_set_max_size();
2158
2159         /* Setup the dispatcher thread */
2160         ret = pthread_create(&dispatcher_thread, NULL,
2161                         relay_thread_dispatcher, (void *) NULL);
2162         if (ret != 0) {
2163                 PERROR("pthread_create dispatcher");
2164                 goto exit_dispatcher;
2165         }
2166
2167         /* Setup the worker thread */
2168         ret = pthread_create(&worker_thread, NULL,
2169                         relay_thread_worker, (void *) NULL);
2170         if (ret != 0) {
2171                 PERROR("pthread_create worker");
2172                 goto exit_worker;
2173         }
2174
2175         /* Setup the listener thread */
2176         ret = pthread_create(&listener_thread, NULL,
2177                         relay_thread_listener, (void *) NULL);
2178         if (ret != 0) {
2179                 PERROR("pthread_create listener");
2180                 goto exit_listener;
2181         }
2182
2183 exit_listener:
2184         ret = pthread_join(listener_thread, &status);
2185         if (ret != 0) {
2186                 PERROR("pthread_join");
2187                 goto error;     /* join error, exit without cleanup */
2188         }
2189
2190 exit_worker:
2191         ret = pthread_join(worker_thread, &status);
2192         if (ret != 0) {
2193                 PERROR("pthread_join");
2194                 goto error;     /* join error, exit without cleanup */
2195         }
2196
2197 exit_dispatcher:
2198         ret = pthread_join(dispatcher_thread, &status);
2199         if (ret != 0) {
2200                 PERROR("pthread_join");
2201                 goto error;     /* join error, exit without cleanup */
2202         }
2203
2204 exit:
2205         cleanup();
2206         if (!ret) {
2207                 exit(EXIT_SUCCESS);
2208         }
2209
2210 error:
2211         exit(EXIT_FAILURE);
2212 }