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  * Return the realpath(3) of the path even if the last directory token does not
 690  * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the
 691  * /tmp/test1 does, the real path is returned. In normal time, realpath(3)
 692  * fails if the end point directory does not exist.
 693  */
 694 static
 695 char *expand_full_path(const char *path)
 696 {
 697         const char *end_path = path;
 698         char *next, *cut_path, *expanded_path, *respath;
 699
 700         /* Find last token delimited by '/' */
 701         while ((next = strpbrk(end_path + 1, "/"))) {
 702                 end_path = next;
 703         }
 704
 705         /* Cut last token from original path */
 706         cut_path = strndup(path, end_path - path);
 707
 708         expanded_path = malloc(PATH_MAX);
 709         if (expanded_path == NULL) {
 710                 respath = NULL;
 711                 goto end;
 712         }
 713
 714         respath = realpath(cut_path, expanded_path);
 715         if (respath == NULL) {
 716                 switch (errno) {
 717                 case ENOENT:
 718                         ERR("%s: No such file or directory", cut_path);
 719                         break;
 720                 default:
 721                         PERROR("realpath");
 722                         break;
 723                 }
 724                 free(expanded_path);
 725         } else {
 726                 /* Add end part to expanded path */
 727                 strcat(respath, end_path);
 728         }
 729 end:
 730         free(cut_path);
 731         return respath;
 732 }
 733
 734
 735 /*
 736  *  config_get_default_path
 737  *
 738  *  Returns the HOME directory path. Caller MUST NOT free(3) the return pointer.
 739  */
 740 static
 741 char *config_get_default_path(void)
 742 {
 743         return getenv("HOME");
 744 }
 745
 746 /*
 747  * Create recursively directory using the FULL path.
 748  */
 749 static
 750 int mkdir_recursive(char *path, mode_t mode)
 751 {
 752         char *p, tmp[PATH_MAX];
 753         struct stat statbuf;
 754         size_t len;
 755         int ret;
 756
 757         ret = snprintf(tmp, sizeof(tmp), "%s", path);
 758         if (ret < 0) {
 759                 PERROR("snprintf mkdir");
 760                 goto error;
 761         }
 762
 763         len = ret;
 764         if (tmp[len - 1] == '/') {
 765                 tmp[len - 1] = 0;
 766         }
 767
 768         for (p = tmp + 1; *p; p++) {
 769                 if (*p == '/') {
 770                         *p = 0;
 771                         if (tmp[strlen(tmp) - 1] == '.' &&
 772                                         tmp[strlen(tmp) - 2] == '.' &&
 773                                         tmp[strlen(tmp) - 3] == '/') {
 774                                 ERR("Using '/../' is not permitted in the trace path (%s)",
 775                                                 tmp);
 776                                 ret = -1;
 777                                 goto error;
 778                         }
 779                         ret = stat(tmp, &statbuf);
 780                         if (ret < 0) {
 781                                 ret = mkdir(tmp, mode);
 782                                 if (ret < 0) {
 783                                         if (errno != EEXIST) {
 784                                                 PERROR("mkdir recursive");
 785                                                 ret = -errno;
 786                                                 goto error;
 787                                         }
 788                                 }
 789                         }
 790                         *p = '/';
 791                 }
 792         }
 793
 794         ret = mkdir(tmp, mode);
 795         if (ret < 0) {
 796                 if (errno != EEXIST) {
 797                         PERROR("mkdir recursive last piece");
 798                         ret = -errno;
 799                 } else {
 800                         ret = 0;
 801                 }
 802         }
 803
 804 error:
 805         return ret;
 806 }
 807
 808 static
 809 char *create_output_path_auto(char *path_name)
 810 {
 811         int ret;
 812         char *traces_path = NULL;
 813         char *alloc_path = NULL;
 814         char *default_path;
 815
 816         default_path = config_get_default_path();
 817         if (default_path == NULL) {
 818                 ERR("Home path not found.\n \
 819                                 Please specify an output path using -o, --output PATH");
 820                 goto exit;
 821         }
 822         alloc_path = strdup(default_path);
 823         if (alloc_path == NULL) {
 824                 PERROR("Path allocation");
 825                 goto exit;
 826         }
 827         ret = asprintf(&traces_path, "%s/" DEFAULT_TRACE_DIR_NAME
 828                         "/%s", alloc_path, path_name);
 829         if (ret < 0) {
 830                 PERROR("asprintf trace dir name");
 831                 goto exit;
 832         }
 833 exit:
 834         free(alloc_path);
 835         return traces_path;
 836 }
 837
 838 static
 839 char *create_output_path_noauto(char *path_name)
 840 {
 841         int ret;
 842         char *traces_path = NULL;
 843         char *full_path;
 844
 845         full_path = expand_full_path(opt_output_path);
 846         ret = asprintf(&traces_path, "%s/%s", full_path, path_name);
 847         if (ret < 0) {
 848                 PERROR("asprintf trace dir name");
 849                 goto exit;
 850         }
 851 exit:
 852         free(full_path);
 853         return traces_path;
 854 }
 855
 856 /*
 857  * create_output_path: create the output trace directory
 858  */
 859 static
 860 char *create_output_path(char *path_name)
 861 {
 862         if (opt_output_path == NULL) {
 863                 return create_output_path_auto(path_name);
 864         } else {
 865                 return create_output_path_noauto(path_name);
 866         }
 867 }
 868
 869 /*
 870  * Get stream from stream id.
 871  * Need to be called with RCU read-side lock held.
 872  */
 873 static
 874 struct relay_stream *relay_stream_from_stream_id(uint64_t stream_id,
 875                 struct lttng_ht *streams_ht)
 876 {
 877         struct lttng_ht_node_ulong *node;
 878         struct lttng_ht_iter iter;
 879         struct relay_stream *ret;
 880
 881         lttng_ht_lookup(streams_ht,
 882                         (void *)((unsigned long) stream_id),
 883                         &iter);
 884         node = lttng_ht_iter_get_node_ulong(&iter);
 885         if (node == NULL) {
 886                 DBG("Relay stream %" PRIu64 " not found", stream_id);
 887                 ret = NULL;
 888                 goto end;
 889         }
 890
 891         ret = caa_container_of(node, struct relay_stream, stream_n);
 892
 893 end:
 894         return ret;
 895 }
 896
 897 static
 898 void deferred_free_stream(struct rcu_head *head)
 899 {
 900         struct relay_stream *stream =
 901                 caa_container_of(head, struct relay_stream, rcu_node);
 902         free(stream);
 903 }
 904
 905 /*
 906  * relay_delete_session: Free all memory associated with a session and
 907  * close all the FDs
 908  */
 909 static
 910 void relay_delete_session(struct relay_command *cmd, struct lttng_ht *streams_ht)
 911 {
 912         struct lttng_ht_iter iter;
 913         struct lttng_ht_node_ulong *node;
 914         struct relay_stream *stream;
 915         int ret;
 916
 917         if (!cmd->session) {
 918                 return;
 919         }
 920
 921         DBG("Relay deleting session %" PRIu64, cmd->session->id);
 922
 923         rcu_read_lock();
 924         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, node, node) {
 925                 node = lttng_ht_iter_get_node_ulong(&iter);
 926                 if (node) {
 927                         stream = caa_container_of(node,
 928                                         struct relay_stream, stream_n);
 929                         if (stream->session == cmd->session) {
 930                                 ret = close(stream->fd);
 931                                 if (ret < 0) {
 932                                         PERROR("close stream fd on delete session");
 933                                 }
 934                                 ret = lttng_ht_del(streams_ht, &iter);
 935                                 assert(!ret);
 936                                 call_rcu(&stream->rcu_node,
 937                                         deferred_free_stream);
 938                         }
 939                 }
 940         }
 941         rcu_read_unlock();
 942
 943         free(cmd->session);
 944 }
 945
 946 /*
 947  * Handle the RELAYD_CREATE_SESSION command.
 948  *
 949  * On success, send back the session id or else return a negative value.
 950  */
 951 static
 952 int relay_create_session(struct lttcomm_relayd_hdr *recv_hdr,
 953                 struct relay_command *cmd)
 954 {
 955         int ret = 0, send_ret;
 956         struct relay_session *session;
 957         struct lttcomm_relayd_status_session reply;
 958
 959         assert(recv_hdr);
 960         assert(cmd);
 961
 962         memset(&reply, 0, sizeof(reply));
 963
 964         session = zmalloc(sizeof(struct relay_session));
 965         if (session == NULL) {
 966                 PERROR("relay session zmalloc");
 967                 ret = -1;
 968                 goto error;
 969         }
 970
 971         session->id = ++last_relay_session_id;
 972         session->sock = cmd->sock;
 973         cmd->session = session;
 974
 975         reply.session_id = htobe64(session->id);
 976
 977         DBG("Created session %" PRIu64, session->id);
 978
 979 error:
 980         if (ret < 0) {
 981                 reply.ret_code = htobe32(LTTNG_ERR_FATAL);
 982         } else {
 983                 reply.ret_code = htobe32(LTTNG_OK);
 984         }
 985
 986         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
 987         if (send_ret < 0) {
 988                 ERR("Relayd sending session id");
 989                 ret = send_ret;
 990         }
 991
 992         return ret;
 993 }
 994
 995 /*
 996  * relay_add_stream: allocate a new stream for a session
 997  */
 998 static
 999 int relay_add_stream(struct lttcomm_relayd_hdr *recv_hdr,
1000                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1001 {
1002         struct relay_session *session = cmd->session;
1003         struct lttcomm_relayd_add_stream stream_info;
1004         struct relay_stream *stream = NULL;
1005         struct lttcomm_relayd_status_stream reply;
1006         char *path = NULL, *root_path = NULL;
1007         int ret, send_ret;
1008
1009         if (!session || cmd->version_check_done == 0) {
1010                 ERR("Trying to add a stream before version check");
1011                 ret = -1;
1012                 goto end_no_session;
1013         }
1014
1015         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
1016                         sizeof(struct lttcomm_relayd_add_stream), 0);
1017         if (ret < sizeof(struct lttcomm_relayd_add_stream)) {
1018                 if (ret == 0) {
1019                         /* Orderly shutdown. Not necessary to print an error. */
1020                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1021                 } else {
1022                         ERR("Relay didn't receive valid add_stream struct size : %d", ret);
1023                 }
1024                 ret = -1;
1025                 goto end_no_session;
1026         }
1027         stream = zmalloc(sizeof(struct relay_stream));
1028         if (stream == NULL) {
1029                 PERROR("relay stream zmalloc");
1030                 ret = -1;
1031                 goto end_no_session;
1032         }
1033
1034         rcu_read_lock();
1035         stream->stream_handle = ++last_relay_stream_id;
1036         stream->prev_seq = -1ULL;
1037         stream->session = session;
1038
1039         root_path = create_output_path(stream_info.pathname);
1040         if (!root_path) {
1041                 ret = -1;
1042                 goto end;
1043         }
1044         ret = mkdir_recursive(root_path, S_IRWXU | S_IRWXG);
1045         if (ret < 0) {
1046                 ERR("relay creating output directory");
1047                 goto end;
1048         }
1049
1050         ret = asprintf(&path, "%s/%s", root_path, stream_info.channel_name);
1051         if (ret < 0) {
1052                 PERROR("asprintf stream path");
1053                 goto end;
1054         }
1055
1056         ret = open(path, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
1057         if (ret < 0) {
1058                 PERROR("Relay creating trace file");
1059                 goto end;
1060         }
1061
1062         stream->fd = ret;
1063         DBG("Tracefile %s created", path);
1064
1065         lttng_ht_node_init_ulong(&stream->stream_n,
1066                         (unsigned long) stream->stream_handle);
1067         lttng_ht_add_unique_ulong(streams_ht,
1068                         &stream->stream_n);
1069
1070         DBG("Relay new stream added %s", stream_info.channel_name);
1071
1072 end:
1073         free(path);
1074         free(root_path);
1075         /* send the session id to the client or a negative return code on error */
1076         if (ret < 0) {
1077                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1078         } else {
1079                 reply.ret_code = htobe32(LTTNG_OK);
1080         }
1081         reply.handle = htobe64(stream->stream_handle);
1082         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1083                         sizeof(struct lttcomm_relayd_status_stream), 0);
1084         if (send_ret < 0) {
1085                 ERR("Relay sending stream id");
1086                 ret = send_ret;
1087         }
1088         rcu_read_unlock();
1089
1090 end_no_session:
1091         return ret;
1092 }
1093
1094 /*
1095  * relay_close_stream: close a specific stream
1096  */
1097 static
1098 int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
1099                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1100 {
1101         struct relay_session *session = cmd->session;
1102         struct lttcomm_relayd_close_stream stream_info;
1103         struct lttcomm_relayd_generic_reply reply;
1104         struct relay_stream *stream;
1105         int ret, send_ret;
1106         struct lttng_ht_iter iter;
1107
1108         DBG("Close stream received");
1109
1110         if (!session || cmd->version_check_done == 0) {
1111                 ERR("Trying to close a stream before version check");
1112                 ret = -1;
1113                 goto end_no_session;
1114         }
1115
1116         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
1117                         sizeof(struct lttcomm_relayd_close_stream), 0);
1118         if (ret < sizeof(struct lttcomm_relayd_close_stream)) {
1119                 if (ret == 0) {
1120                         /* Orderly shutdown. Not necessary to print an error. */
1121                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1122                 } else {
1123                         ERR("Relay didn't receive valid add_stream struct size : %d", ret);
1124                 }
1125                 ret = -1;
1126                 goto end_no_session;
1127         }
1128
1129         rcu_read_lock();
1130         stream = relay_stream_from_stream_id(be64toh(stream_info.stream_id),
1131                         streams_ht);
1132         if (!stream) {
1133                 ret = -1;
1134                 goto end_unlock;
1135         }
1136
1137         stream->last_net_seq_num = be64toh(stream_info.last_net_seq_num);
1138         stream->close_flag = 1;
1139
1140         if (close_stream_check(stream)) {
1141                 int delret;
1142
1143                 delret = close(stream->fd);
1144                 if (delret < 0) {
1145                         PERROR("close stream");
1146                 }
1147                 iter.iter.node = &stream->stream_n.node;
1148                 delret = lttng_ht_del(streams_ht, &iter);
1149                 assert(!delret);
1150                 call_rcu(&stream->rcu_node,
1151                                 deferred_free_stream);
1152                 DBG("Closed tracefile %d from close stream", stream->fd);
1153         }
1154
1155 end_unlock:
1156         rcu_read_unlock();
1157
1158         if (ret < 0) {
1159                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1160         } else {
1161                 reply.ret_code = htobe32(LTTNG_OK);
1162         }
1163         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1164                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1165         if (send_ret < 0) {
1166                 ERR("Relay sending stream id");
1167                 ret = send_ret;
1168         }
1169
1170 end_no_session:
1171         return ret;
1172 }
1173
1174 /*
1175  * relay_unknown_command: send -1 if received unknown command
1176  */
1177 static
1178 void relay_unknown_command(struct relay_command *cmd)
1179 {
1180         struct lttcomm_relayd_generic_reply reply;
1181         int ret;
1182
1183         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1184         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1185                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1186         if (ret < 0) {
1187                 ERR("Relay sending unknown command");
1188         }
1189 }
1190
1191 /*
1192  * relay_start: send an acknowledgment to the client to tell if we are
1193  * ready to receive data. We are ready if a session is established.
1194  */
1195 static
1196 int relay_start(struct lttcomm_relayd_hdr *recv_hdr,
1197                 struct relay_command *cmd)
1198 {
1199         int ret = htobe32(LTTNG_OK);
1200         struct lttcomm_relayd_generic_reply reply;
1201         struct relay_session *session = cmd->session;
1202
1203         if (!session) {
1204                 DBG("Trying to start the streaming without a session established");
1205                 ret = htobe32(LTTNG_ERR_UNK);
1206         }
1207
1208         reply.ret_code = ret;
1209         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1210                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1211         if (ret < 0) {
1212                 ERR("Relay sending start ack");
1213         }
1214
1215         return ret;
1216 }
1217
1218 /*
1219  * Append padding to the file pointed by the file descriptor fd.
1220  */
1221 static int write_padding_to_file(int fd, uint32_t size)
1222 {
1223         int ret = 0;
1224         char *zeros;
1225
1226         if (size == 0) {
1227                 goto end;
1228         }
1229
1230         zeros = zmalloc(size);
1231         if (zeros == NULL) {
1232                 PERROR("zmalloc zeros for padding");
1233                 ret = -1;
1234                 goto end;
1235         }
1236
1237         do {
1238                 ret = write(fd, zeros, size);
1239         } while (ret < 0 && errno == EINTR);
1240         if (ret < 0 || ret != size) {
1241                 PERROR("write padding to file");
1242         }
1243
1244         free(zeros);
1245
1246 end:
1247         return ret;
1248 }
1249
1250 /*
1251  * relay_recv_metadata: receive the metada for the session.
1252  */
1253 static
1254 int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
1255                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1256 {
1257         int ret = htobe32(LTTNG_OK);
1258         struct relay_session *session = cmd->session;
1259         struct lttcomm_relayd_metadata_payload *metadata_struct;
1260         struct relay_stream *metadata_stream;
1261         uint64_t data_size, payload_size;
1262
1263         if (!session) {
1264                 ERR("Metadata sent before version check");
1265                 ret = -1;
1266                 goto end;
1267         }
1268
1269         data_size = payload_size = be64toh(recv_hdr->data_size);
1270         if (data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
1271                 ERR("Incorrect data size");
1272                 ret = -1;
1273                 goto end;
1274         }
1275         payload_size -= sizeof(struct lttcomm_relayd_metadata_payload);
1276
1277         if (data_buffer_size < data_size) {
1278                 /* In case the realloc fails, we can free the memory */
1279                 char *tmp_data_ptr;
1280
1281                 tmp_data_ptr = realloc(data_buffer, data_size);
1282                 if (!tmp_data_ptr) {
1283                         ERR("Allocating data buffer");
1284                         free(data_buffer);
1285                         ret = -1;
1286                         goto end;
1287                 }
1288                 data_buffer = tmp_data_ptr;
1289                 data_buffer_size = data_size;
1290         }
1291         memset(data_buffer, 0, data_size);
1292         DBG2("Relay receiving metadata, waiting for %" PRIu64 " bytes", data_size);
1293         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1294         if (ret < 0 || ret != data_size) {
1295                 if (ret == 0) {
1296                         /* Orderly shutdown. Not necessary to print an error. */
1297                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1298                 } else {
1299                         ERR("Relay didn't receive the whole metadata");
1300                 }
1301                 ret = -1;
1302                 goto end;
1303         }
1304         metadata_struct = (struct lttcomm_relayd_metadata_payload *) data_buffer;
1305
1306         rcu_read_lock();
1307         metadata_stream = relay_stream_from_stream_id(
1308                         be64toh(metadata_struct->stream_id), streams_ht);
1309         if (!metadata_stream) {
1310                 ret = -1;
1311                 goto end_unlock;
1312         }
1313
1314         do {
1315                 ret = write(metadata_stream->fd, metadata_struct->payload,
1316                                 payload_size);
1317         } while (ret < 0 && errno == EINTR);
1318         if (ret < 0 || ret != payload_size) {
1319                 ERR("Relay error writing metadata on file");
1320                 ret = -1;
1321                 goto end_unlock;
1322         }
1323
1324         ret = write_padding_to_file(metadata_stream->fd,
1325                         be32toh(metadata_struct->padding_size));
1326         if (ret < 0) {
1327                 goto end_unlock;
1328         }
1329
1330         DBG2("Relay metadata written");
1331
1332 end_unlock:
1333         rcu_read_unlock();
1334 end:
1335         return ret;
1336 }
1337
1338 /*
1339  * relay_send_version: send relayd version number
1340  */
1341 static
1342 int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
1343                 struct relay_command *cmd)
1344 {
1345         int ret;
1346         struct lttcomm_relayd_version reply, msg;
1347
1348         assert(cmd);
1349
1350         cmd->version_check_done = 1;
1351
1352         /* Get version from the other side. */
1353         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1354         if (ret < 0 || ret != sizeof(msg)) {
1355                 if (ret == 0) {
1356                         /* Orderly shutdown. Not necessary to print an error. */
1357                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1358                 } else {
1359                         ERR("Relay failed to receive the version values.");
1360                 }
1361                 ret = -1;
1362                 goto end;
1363         }
1364
1365         /*
1366          * For now, we just ignore the received version but after 2.1 stable
1367          * release, a check must be done to see if we either adapt to the other
1368          * side version (which MUST be lower than us) or keep the latest data
1369          * structure considering that the other side will adapt.
1370          */
1371
1372         ret = sscanf(VERSION, "%10u.%10u", &reply.major, &reply.minor);
1373         if (ret < 2) {
1374                 ERR("Error in scanning version");
1375                 ret = -1;
1376                 goto end;
1377         }
1378         reply.major = htobe32(reply.major);
1379         reply.minor = htobe32(reply.minor);
1380         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1381                         sizeof(struct lttcomm_relayd_version), 0);
1382         if (ret < 0) {
1383                 ERR("Relay sending version");
1384         }
1385         DBG("Version check done (%u.%u)", be32toh(reply.major),
1386                         be32toh(reply.minor));
1387
1388 end:
1389         return ret;
1390 }
1391
1392 /*
1393  * Check for data pending for a given stream id from the session daemon.
1394  */
1395 static
1396 int relay_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1397                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1398 {
1399         struct relay_session *session = cmd->session;
1400         struct lttcomm_relayd_data_pending msg;
1401         struct lttcomm_relayd_generic_reply reply;
1402         struct relay_stream *stream;
1403         int ret;
1404         uint64_t last_net_seq_num, stream_id;
1405
1406         DBG("Data pending command received");
1407
1408         if (!session || cmd->version_check_done == 0) {
1409                 ERR("Trying to check for data before version check");
1410                 ret = -1;
1411                 goto end_no_session;
1412         }
1413
1414         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1415         if (ret < sizeof(msg)) {
1416                 if (ret == 0) {
1417                         /* Orderly shutdown. Not necessary to print an error. */
1418                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1419                 } else {
1420                         ERR("Relay didn't receive valid data_pending struct size : %d",
1421                                         ret);
1422                 }
1423                 ret = -1;
1424                 goto end_no_session;
1425         }
1426
1427         stream_id = be64toh(msg.stream_id);
1428         last_net_seq_num = be64toh(msg.last_net_seq_num);
1429
1430         rcu_read_lock();
1431         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1432         if (stream == NULL) {
1433                 ret = -1;
1434                 goto end_unlock;
1435         }
1436
1437         DBG("Data pending for stream id %" PRIu64 " prev_seq %" PRIu64
1438                         " and last_seq %" PRIu64, stream_id, stream->prev_seq,
1439                         last_net_seq_num);
1440
1441         /* Avoid wrapping issue */
1442         if (((int64_t) (stream->prev_seq - last_net_seq_num)) >= 0) {
1443                 /* Data has in fact been written and is NOT pending */
1444                 ret = 0;
1445         } else {
1446                 /* Data still being streamed thus pending */
1447                 ret = 1;
1448         }
1449
1450         /* Pending check is now done. */
1451         stream->data_pending_check_done = 1;
1452
1453 end_unlock:
1454         rcu_read_unlock();
1455
1456         reply.ret_code = htobe32(ret);
1457         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1458         if (ret < 0) {
1459                 ERR("Relay data pending ret code failed");
1460         }
1461
1462 end_no_session:
1463         return ret;
1464 }
1465
1466 /*
1467  * Wait for the control socket to reach a quiescent state.
1468  *
1469  * Note that for now, when receiving this command from the session daemon, this
1470  * means that every subsequent commands or data received on the control socket
1471  * has been handled. So, this is why we simply return OK here.
1472  */
1473 static
1474 int relay_quiescent_control(struct lttcomm_relayd_hdr *recv_hdr,
1475                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1476 {
1477         int ret;
1478         uint64_t stream_id;
1479         struct relay_stream *stream;
1480         struct lttng_ht_iter iter;
1481         struct lttcomm_relayd_quiescent_control msg;
1482         struct lttcomm_relayd_generic_reply reply;
1483
1484         DBG("Checking quiescent state on control socket");
1485
1486         if (!cmd->session || cmd->version_check_done == 0) {
1487                 ERR("Trying to check for data before version check");
1488                 ret = -1;
1489                 goto end_no_session;
1490         }
1491
1492         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1493         if (ret < sizeof(msg)) {
1494                 if (ret == 0) {
1495                         /* Orderly shutdown. Not necessary to print an error. */
1496                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1497                 } else {
1498                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1499                                         ret);
1500                 }
1501                 ret = -1;
1502                 goto end_no_session;
1503         }
1504
1505         stream_id = be64toh(msg.stream_id);
1506
1507         rcu_read_lock();
1508         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1509                 if (stream->stream_handle == stream_id) {
1510                         stream->data_pending_check_done = 1;
1511                         DBG("Relay quiescent control pending flag set to %" PRIu64,
1512                                         stream_id);
1513                         break;
1514                 }
1515         }
1516         rcu_read_unlock();
1517
1518         reply.ret_code = htobe32(LTTNG_OK);
1519         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1520         if (ret < 0) {
1521                 ERR("Relay data quiescent control ret code failed");
1522         }
1523
1524 end_no_session:
1525         return ret;
1526 }
1527
1528 /*
1529  * Initialize a data pending command. This means that a client is about to ask
1530  * for data pending for each stream he/she holds. Simply iterate over all
1531  * streams of a session and set the data_pending_check_done flag.
1532  *
1533  * This command returns to the client a LTTNG_OK code.
1534  */
1535 static
1536 int relay_begin_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1537                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1538 {
1539         int ret;
1540         struct lttng_ht_iter iter;
1541         struct lttcomm_relayd_begin_data_pending msg;
1542         struct lttcomm_relayd_generic_reply reply;
1543         struct relay_stream *stream;
1544         uint64_t session_id;
1545
1546         assert(recv_hdr);
1547         assert(cmd);
1548         assert(streams_ht);
1549
1550         DBG("Init streams for data pending");
1551
1552         if (!cmd->session || cmd->version_check_done == 0) {
1553                 ERR("Trying to check for data before version check");
1554                 ret = -1;
1555                 goto end_no_session;
1556         }
1557
1558         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1559         if (ret < sizeof(msg)) {
1560                 if (ret == 0) {
1561                         /* Orderly shutdown. Not necessary to print an error. */
1562                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1563                 } else {
1564                         ERR("Relay didn't receive valid begin data_pending struct size: %d",
1565                                         ret);
1566                 }
1567                 ret = -1;
1568                 goto end_no_session;
1569         }
1570
1571         session_id = be64toh(msg.session_id);
1572
1573         /*
1574          * Iterate over all streams to set the begin data pending flag. For now, the
1575          * streams are indexed by stream handle so we have to iterate over all
1576          * streams to find the one associated with the right session_id.
1577          */
1578         rcu_read_lock();
1579         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1580                 if (stream->session->id == session_id) {
1581                         stream->data_pending_check_done = 0;
1582                         DBG("Set begin data pending flag to stream %" PRIu64,
1583                                         stream->stream_handle);
1584                 }
1585         }
1586         rcu_read_unlock();
1587
1588         /* All good, send back reply. */
1589         reply.ret_code = htobe32(LTTNG_OK);
1590
1591         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1592         if (ret < 0) {
1593                 ERR("Relay begin data pending send reply failed");
1594         }
1595
1596 end_no_session:
1597         return ret;
1598 }
1599
1600 /*
1601  * End data pending command. This will check, for a given session id, if each
1602  * stream associated with it has its data_pending_check_done flag set. If not,
1603  * this means that the client lost track of the stream but the data is still
1604  * being streamed on our side. In this case, we inform the client that data is
1605  * inflight.
1606  *
1607  * Return to the client if there is data in flight or not with a ret_code.
1608  */
1609 static
1610 int relay_end_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1611                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1612 {
1613         int ret;
1614         struct lttng_ht_iter iter;
1615         struct lttcomm_relayd_end_data_pending msg;
1616         struct lttcomm_relayd_generic_reply reply;
1617         struct relay_stream *stream;
1618         uint64_t session_id;
1619         uint32_t is_data_inflight = 0;
1620
1621         assert(recv_hdr);
1622         assert(cmd);
1623         assert(streams_ht);
1624
1625         DBG("End data pending command");
1626
1627         if (!cmd->session || cmd->version_check_done == 0) {
1628                 ERR("Trying to check for data before version check");
1629                 ret = -1;
1630                 goto end_no_session;
1631         }
1632
1633         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1634         if (ret < sizeof(msg)) {
1635                 if (ret == 0) {
1636                         /* Orderly shutdown. Not necessary to print an error. */
1637                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1638                 } else {
1639                         ERR("Relay didn't receive valid end data_pending struct size: %d",
1640                                         ret);
1641                 }
1642                 ret = -1;
1643                 goto end_no_session;
1644         }
1645
1646         session_id = be64toh(msg.session_id);
1647
1648         /* Iterate over all streams to see if the begin data pending flag is set. */
1649         rcu_read_lock();
1650         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1651                 if (stream->session->id == session_id &&
1652                                 !stream->data_pending_check_done) {
1653                         is_data_inflight = 1;
1654                         DBG("Data is still in flight for stream %" PRIu64,
1655                                         stream->stream_handle);
1656                         break;
1657                 }
1658         }
1659         rcu_read_unlock();
1660
1661         /* All good, send back reply. */
1662         reply.ret_code = htobe32(is_data_inflight);
1663
1664         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1665         if (ret < 0) {
1666                 ERR("Relay end data pending send reply failed");
1667         }
1668
1669 end_no_session:
1670         return ret;
1671 }
1672
1673 /*
1674  * relay_process_control: Process the commands received on the control socket
1675  */
1676 static
1677 int relay_process_control(struct lttcomm_relayd_hdr *recv_hdr,
1678                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1679 {
1680         int ret = 0;
1681
1682         switch (be32toh(recv_hdr->cmd)) {
1683         case RELAYD_CREATE_SESSION:
1684                 ret = relay_create_session(recv_hdr, cmd);
1685                 break;
1686         case RELAYD_ADD_STREAM:
1687                 ret = relay_add_stream(recv_hdr, cmd, streams_ht);
1688                 break;
1689         case RELAYD_START_DATA:
1690                 ret = relay_start(recv_hdr, cmd);
1691                 break;
1692         case RELAYD_SEND_METADATA:
1693                 ret = relay_recv_metadata(recv_hdr, cmd, streams_ht);
1694                 break;
1695         case RELAYD_VERSION:
1696                 ret = relay_send_version(recv_hdr, cmd);
1697                 break;
1698         case RELAYD_CLOSE_STREAM:
1699                 ret = relay_close_stream(recv_hdr, cmd, streams_ht);
1700                 break;
1701         case RELAYD_DATA_PENDING:
1702                 ret = relay_data_pending(recv_hdr, cmd, streams_ht);
1703                 break;
1704         case RELAYD_QUIESCENT_CONTROL:
1705                 ret = relay_quiescent_control(recv_hdr, cmd, streams_ht);
1706                 break;
1707         case RELAYD_BEGIN_DATA_PENDING:
1708                 ret = relay_begin_data_pending(recv_hdr, cmd, streams_ht);
1709                 break;
1710         case RELAYD_END_DATA_PENDING:
1711                 ret = relay_end_data_pending(recv_hdr, cmd, streams_ht);
1712                 break;
1713         case RELAYD_UPDATE_SYNC_INFO:
1714         default:
1715                 ERR("Received unknown command (%u)", be32toh(recv_hdr->cmd));
1716                 relay_unknown_command(cmd);
1717                 ret = -1;
1718                 goto end;
1719         }
1720
1721 end:
1722         return ret;
1723 }
1724
1725 /*
1726  * relay_process_data: Process the data received on the data socket
1727  */
1728 static
1729 int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
1730 {
1731         int ret = 0;
1732         struct relay_stream *stream;
1733         struct lttcomm_relayd_data_hdr data_hdr;
1734         uint64_t stream_id;
1735         uint64_t net_seq_num;
1736         uint32_t data_size;
1737
1738         ret = cmd->sock->ops->recvmsg(cmd->sock, &data_hdr,
1739                         sizeof(struct lttcomm_relayd_data_hdr), 0);
1740         if (ret <= 0) {
1741                 if (ret == 0) {
1742                         /* Orderly shutdown. Not necessary to print an error. */
1743                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1744                 } else {
1745                         ERR("Unable to receive data header on sock %d", cmd->sock->fd);
1746                 }
1747                 ret = -1;
1748                 goto end;
1749         }
1750
1751         stream_id = be64toh(data_hdr.stream_id);
1752
1753         rcu_read_lock();
1754         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1755         if (!stream) {
1756                 ret = -1;
1757                 goto end_unlock;
1758         }
1759
1760         data_size = be32toh(data_hdr.data_size);
1761         if (data_buffer_size < data_size) {
1762                 char *tmp_data_ptr;
1763
1764                 tmp_data_ptr = realloc(data_buffer, data_size);
1765                 if (!tmp_data_ptr) {
1766                         ERR("Allocating data buffer");
1767                         free(data_buffer);
1768                         ret = -1;
1769                         goto end_unlock;
1770                 }
1771                 data_buffer = tmp_data_ptr;
1772                 data_buffer_size = data_size;
1773         }
1774         memset(data_buffer, 0, data_size);
1775
1776         net_seq_num = be64toh(data_hdr.net_seq_num);
1777
1778         DBG3("Receiving data of size %u for stream id %" PRIu64 " seqnum %" PRIu64,
1779                 data_size, stream_id, net_seq_num);
1780         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1781         if (ret <= 0) {
1782                 if (ret == 0) {
1783                         /* Orderly shutdown. Not necessary to print an error. */
1784                         DBG("Socket %d did an orderly shutdown", cmd->sock->fd);
1785                 }
1786                 ret = -1;
1787                 goto end_unlock;
1788         }
1789
1790         do {
1791                 ret = write(stream->fd, data_buffer, data_size);
1792         } while (ret < 0 && errno == EINTR);
1793         if (ret < 0 || ret != data_size) {
1794                 ERR("Relay error writing data to file");
1795                 ret = -1;
1796                 goto end_unlock;
1797         }
1798
1799         DBG2("Relay wrote %d bytes to tracefile for stream id %" PRIu64,
1800                         ret, stream->stream_handle);
1801
1802         ret = write_padding_to_file(stream->fd, be32toh(data_hdr.padding_size));
1803         if (ret < 0) {
1804                 goto end_unlock;
1805         }
1806
1807         stream->prev_seq = net_seq_num;
1808
1809         /* Check if we need to close the FD */
1810         if (close_stream_check(stream)) {
1811                 int cret;
1812                 struct lttng_ht_iter iter;
1813
1814                 cret = close(stream->fd);
1815                 if (cret < 0) {
1816                         PERROR("close stream process data");
1817                 }
1818                 iter.iter.node = &stream->stream_n.node;
1819                 ret = lttng_ht_del(streams_ht, &iter);
1820                 assert(!ret);
1821                 call_rcu(&stream->rcu_node,
1822                         deferred_free_stream);
1823                 DBG("Closed tracefile %d after recv data", stream->fd);
1824         }
1825
1826 end_unlock:
1827         rcu_read_unlock();
1828 end:
1829         return ret;
1830 }
1831
1832 static
1833 void relay_cleanup_poll_connection(struct lttng_poll_event *events, int pollfd)
1834 {
1835         int ret;
1836
1837         lttng_poll_del(events, pollfd);
1838
1839         ret = close(pollfd);
1840         if (ret < 0) {
1841                 ERR("Closing pollfd %d", pollfd);
1842         }
1843 }
1844
1845 static
1846 int relay_add_connection(int fd, struct lttng_poll_event *events,
1847                 struct lttng_ht *relay_connections_ht)
1848 {
1849         struct relay_command *relay_connection;
1850         int ret;
1851
1852         relay_connection = zmalloc(sizeof(struct relay_command));
1853         if (relay_connection == NULL) {
1854                 PERROR("Relay command zmalloc");
1855                 goto error;
1856         }
1857         do {
1858                 ret = read(fd, relay_connection, sizeof(struct relay_command));
1859         } while (ret < 0 && errno == EINTR);
1860         if (ret < 0 || ret < sizeof(struct relay_command)) {
1861                 PERROR("read relay cmd pipe");
1862                 goto error_read;
1863         }
1864
1865         lttng_ht_node_init_ulong(&relay_connection->sock_n,
1866                         (unsigned long) relay_connection->sock->fd);
1867         rcu_read_lock();
1868         lttng_ht_add_unique_ulong(relay_connections_ht,
1869                         &relay_connection->sock_n);
1870         rcu_read_unlock();
1871         return lttng_poll_add(events,
1872                         relay_connection->sock->fd,
1873                         LPOLLIN | LPOLLRDHUP);
1874
1875 error_read:
1876         free(relay_connection);
1877 error:
1878         return -1;
1879 }
1880
1881 static
1882 void deferred_free_connection(struct rcu_head *head)
1883 {
1884         struct relay_command *relay_connection =
1885                 caa_container_of(head, struct relay_command, rcu_node);
1886
1887         lttcomm_destroy_sock(relay_connection->sock);
1888         free(relay_connection);
1889 }
1890
1891 static
1892 void relay_del_connection(struct lttng_ht *relay_connections_ht,
1893                 struct lttng_ht *streams_ht, struct lttng_ht_iter *iter,
1894                 struct relay_command *relay_connection)
1895 {
1896         int ret;
1897
1898         ret = lttng_ht_del(relay_connections_ht, iter);
1899         assert(!ret);
1900         if (relay_connection->type == RELAY_CONTROL) {
1901                 relay_delete_session(relay_connection, streams_ht);
1902         }
1903
1904         call_rcu(&relay_connection->rcu_node,
1905                 deferred_free_connection);
1906 }
1907
1908 /*
1909  * This thread does the actual work
1910  */
1911 static
1912 void *relay_thread_worker(void *data)
1913 {
1914         int ret, err = -1, last_seen_data_fd = -1;
1915         uint32_t nb_fd;
1916         struct relay_command *relay_connection;
1917         struct lttng_poll_event events;
1918         struct lttng_ht *relay_connections_ht;
1919         struct lttng_ht_node_ulong *node;
1920         struct lttng_ht_iter iter;
1921         struct lttng_ht *streams_ht;
1922         struct lttcomm_relayd_hdr recv_hdr;
1923
1924         DBG("[thread] Relay worker started");
1925
1926         rcu_register_thread();
1927
1928         /* table of connections indexed on socket */
1929         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1930         if (!relay_connections_ht) {
1931                 goto relay_connections_ht_error;
1932         }
1933
1934         /* tables of streams indexed by stream ID */
1935         streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1936         if (!streams_ht) {
1937                 goto streams_ht_error;
1938         }
1939
1940         ret = create_thread_poll_set(&events, 2);
1941         if (ret < 0) {
1942                 goto error_poll_create;
1943         }
1944
1945         ret = lttng_poll_add(&events, relay_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1946         if (ret < 0) {
1947                 goto error;
1948         }
1949
1950 restart:
1951         while (1) {
1952                 int idx = -1, i, seen_control = 0, last_notdel_data_fd = -1;
1953
1954                 /* Infinite blocking call, waiting for transmission */
1955                 DBG3("Relayd worker thread polling...");
1956                 ret = lttng_poll_wait(&events, -1);
1957                 if (ret < 0) {
1958                         /*
1959                          * Restart interrupted system call.
1960                          */
1961                         if (errno == EINTR) {
1962                                 goto restart;
1963                         }
1964                         goto error;
1965                 }
1966
1967                 nb_fd = ret;
1968
1969                 /*
1970                  * Process control. The control connection is prioritised so we don't
1971                  * starve it with high throughout put tracing data on the data
1972                  * connection.
1973                  */
1974                 for (i = 0; i < nb_fd; i++) {
1975                         /* Fetch once the poll data */
1976                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
1977                         int pollfd = LTTNG_POLL_GETFD(&events, i);
1978
1979                         /* Thread quit pipe has been closed. Killing thread. */
1980                         ret = check_thread_quit_pipe(pollfd, revents);
1981                         if (ret) {
1982                                 err = 0;
1983                                 goto exit;
1984                         }
1985
1986                         /* Inspect the relay cmd pipe for new connection */
1987                         if (pollfd == relay_cmd_pipe[0]) {
1988                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1989                                         ERR("Relay pipe error");
1990                                         goto error;
1991                                 } else if (revents & LPOLLIN) {
1992                                         DBG("Relay command received");
1993                                         ret = relay_add_connection(relay_cmd_pipe[0],
1994                                                         &events, relay_connections_ht);
1995                                         if (ret < 0) {
1996                                                 goto error;
1997                                         }
1998                                 }
1999                         } else if (revents) {
2000                                 rcu_read_lock();
2001                                 lttng_ht_lookup(relay_connections_ht,
2002                                                 (void *)((unsigned long) pollfd),
2003                                                 &iter);
2004                                 node = lttng_ht_iter_get_node_ulong(&iter);
2005                                 if (node == NULL) {
2006                                         DBG2("Relay sock %d not found", pollfd);
2007                                         rcu_read_unlock();
2008                                         goto error;
2009                                 }
2010                                 relay_connection = caa_container_of(node,
2011                                                 struct relay_command, sock_n);
2012
2013                                 if (revents & (LPOLLERR)) {
2014                                         ERR("POLL ERROR");
2015                                         relay_cleanup_poll_connection(&events, pollfd);
2016                                         relay_del_connection(relay_connections_ht,
2017                                                         streams_ht, &iter,
2018                                                         relay_connection);
2019                                         if (last_seen_data_fd == pollfd) {
2020                                                 last_seen_data_fd = last_notdel_data_fd;
2021                                         }
2022                                 } else if (revents & (LPOLLHUP | LPOLLRDHUP)) {
2023                                         DBG("Socket %d hung up", pollfd);
2024                                         relay_cleanup_poll_connection(&events, pollfd);
2025                                         relay_del_connection(relay_connections_ht,
2026                                                         streams_ht, &iter,
2027                                                         relay_connection);
2028                                         if (last_seen_data_fd == pollfd) {
2029                                                 last_seen_data_fd = last_notdel_data_fd;
2030                                         }
2031                                 } else if (revents & LPOLLIN) {
2032                                         /* control socket */
2033                                         if (relay_connection->type == RELAY_CONTROL) {
2034                                                 ret = relay_connection->sock->ops->recvmsg(
2035                                                                 relay_connection->sock, &recv_hdr,
2036                                                                 sizeof(struct lttcomm_relayd_hdr), 0);
2037                                                 /* connection closed */
2038                                                 if (ret <= 0) {
2039                                                         relay_cleanup_poll_connection(&events, pollfd);
2040                                                         relay_del_connection(relay_connections_ht,
2041                                                                         streams_ht, &iter,
2042                                                                         relay_connection);
2043                                                         DBG("Control connection closed with %d", pollfd);
2044                                                 } else {
2045                                                         if (relay_connection->session) {
2046                                                                 DBG2("Relay worker receiving data for session : %" PRIu64,
2047                                                                                 relay_connection->session->id);
2048                                                         }
2049                                                         ret = relay_process_control(&recv_hdr,
2050                                                                         relay_connection,
2051                                                                         streams_ht);
2052                                                         if (ret < 0) {
2053                                                                 /* Clear the session on error. */
2054                                                                 relay_cleanup_poll_connection(&events, pollfd);
2055                                                                 relay_del_connection(relay_connections_ht,
2056                                                                                 streams_ht, &iter,
2057                                                                                 relay_connection);
2058                                                                 DBG("Connection closed with %d", pollfd);
2059                                                         }
2060                                                         seen_control = 1;
2061                                                 }
2062                                         } else {
2063                                                 /*
2064                                                  * Flag the last seen data fd not deleted. It will be
2065                                                  * used as the last seen fd if any fd gets deleted in
2066                                                  * this first loop.
2067                                                  */
2068                                                 last_notdel_data_fd = pollfd;
2069                                         }
2070                                 }
2071                                 rcu_read_unlock();
2072                         }
2073                 }
2074
2075                 /*
2076                  * The last loop handled a control request, go back to poll to make
2077                  * sure we prioritise the control socket.
2078                  */
2079                 if (seen_control) {
2080                         continue;
2081                 }
2082
2083                 if (last_seen_data_fd >= 0) {
2084                         for (i = 0; i < nb_fd; i++) {
2085                                 int pollfd = LTTNG_POLL_GETFD(&events, i);
2086                                 if (last_seen_data_fd == pollfd) {
2087                                         idx = i;
2088                                         break;
2089                                 }
2090                         }
2091                 }
2092
2093                 /* Process data connection. */
2094                 for (i = idx + 1; i < nb_fd; i++) {
2095                         /* Fetch the poll data. */
2096                         uint32_t revents = LTTNG_POLL_GETEV(&events, i);
2097                         int pollfd = LTTNG_POLL_GETFD(&events, i);
2098
2099                         /* Skip the command pipe. It's handled in the first loop. */
2100                         if (pollfd == relay_cmd_pipe[0]) {
2101                                 continue;
2102                         }
2103
2104                         if (revents) {
2105                                 rcu_read_lock();
2106                                 lttng_ht_lookup(relay_connections_ht,
2107                                                 (void *)((unsigned long) pollfd),
2108                                                 &iter);
2109                                 node = lttng_ht_iter_get_node_ulong(&iter);
2110                                 if (node == NULL) {
2111                                         /* Skip it. Might be removed before. */
2112                                         rcu_read_unlock();
2113                                         continue;
2114                                 }
2115                                 relay_connection = caa_container_of(node,
2116                                                 struct relay_command, sock_n);
2117
2118                                 if (revents & LPOLLIN) {
2119                                         if (relay_connection->type != RELAY_DATA) {
2120                                                 continue;
2121                                         }
2122
2123                                         ret = relay_process_data(relay_connection, streams_ht);
2124                                         /* connection closed */
2125                                         if (ret < 0) {
2126                                                 relay_cleanup_poll_connection(&events, pollfd);
2127                                                 relay_del_connection(relay_connections_ht,
2128                                                                 streams_ht, &iter,
2129                                                                 relay_connection);
2130                                                 DBG("Data connection closed with %d", pollfd);
2131                                                 /*
2132                                                  * Every goto restart call sets the last seen fd where
2133                                                  * here we don't really care since we gracefully
2134                                                  * continue the loop after the connection is deleted.
2135                                                  */
2136                                         } else {
2137                                                 /* Keep last seen port. */
2138                                                 last_seen_data_fd = pollfd;
2139                                                 rcu_read_unlock();
2140                                                 goto restart;
2141                                         }
2142                                 }
2143                                 rcu_read_unlock();
2144                         }
2145                 }
2146                 last_seen_data_fd = -1;
2147         }
2148
2149 exit:
2150 error:
2151         lttng_poll_clean(&events);
2152
2153         /* empty the hash table and free the memory */
2154         rcu_read_lock();
2155         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter, node, node) {
2156                 node = lttng_ht_iter_get_node_ulong(&iter);
2157                 if (node) {
2158                         relay_connection = caa_container_of(node,
2159                                         struct relay_command, sock_n);
2160                         relay_del_connection(relay_connections_ht,
2161                                         streams_ht, &iter,
2162                                         relay_connection);
2163                 }
2164         }
2165         rcu_read_unlock();
2166 error_poll_create:
2167         lttng_ht_destroy(streams_ht);
2168 streams_ht_error:
2169         lttng_ht_destroy(relay_connections_ht);
2170 relay_connections_ht_error:
2171         /* Close relay cmd pipes */
2172         utils_close_pipe(relay_cmd_pipe);
2173         if (err) {
2174                 DBG("Thread exited with error");
2175         }
2176         DBG("Worker thread cleanup complete");
2177         free(data_buffer);
2178         stop_threads();
2179         rcu_unregister_thread();
2180         return NULL;
2181 }
2182
2183 /*
2184  * Create the relay command pipe to wake thread_manage_apps.
2185  * Closed in cleanup().
2186  */
2187 static int create_relay_cmd_pipe(void)
2188 {
2189         int ret;
2190
2191         ret = utils_create_pipe_cloexec(relay_cmd_pipe);
2192
2193         return ret;
2194 }
2195
2196 /*
2197  * main
2198  */
2199 int main(int argc, char **argv)
2200 {
2201         int ret = 0;
2202         void *status;
2203
2204         /* Create thread quit pipe */
2205         if ((ret = init_thread_quit_pipe()) < 0) {
2206                 goto error;
2207         }
2208
2209         /* Parse arguments */
2210         progname = argv[0];
2211         if ((ret = parse_args(argc, argv)) < 0) {
2212                 goto exit;
2213         }
2214
2215         if ((ret = set_signal_handler()) < 0) {
2216                 goto exit;
2217         }
2218
2219         /* Daemonize */
2220         if (opt_daemon) {
2221                 ret = daemon(0, 0);
2222                 if (ret < 0) {
2223                         PERROR("daemon");
2224                         goto exit;
2225                 }
2226         }
2227
2228         /* Check if daemon is UID = 0 */
2229         is_root = !getuid();
2230
2231         if (!is_root) {
2232                 if (control_uri->port < 1024 || data_uri->port < 1024) {
2233                         ERR("Need to be root to use ports < 1024");
2234                         ret = -1;
2235                         goto exit;
2236                 }
2237         }
2238
2239         /* Setup the thread apps communication pipe. */
2240         if ((ret = create_relay_cmd_pipe()) < 0) {
2241                 goto exit;
2242         }
2243
2244         /* Init relay command queue. */
2245         cds_wfq_init(&relay_cmd_queue.queue);
2246
2247         /* Set up max poll set size */
2248         lttng_poll_set_max_size();
2249
2250         /* Setup the dispatcher thread */
2251         ret = pthread_create(&dispatcher_thread, NULL,
2252                         relay_thread_dispatcher, (void *) NULL);
2253         if (ret != 0) {
2254                 PERROR("pthread_create dispatcher");
2255                 goto exit_dispatcher;
2256         }
2257
2258         /* Setup the worker thread */
2259         ret = pthread_create(&worker_thread, NULL,
2260                         relay_thread_worker, (void *) NULL);
2261         if (ret != 0) {
2262                 PERROR("pthread_create worker");
2263                 goto exit_worker;
2264         }
2265
2266         /* Setup the listener thread */
2267         ret = pthread_create(&listener_thread, NULL,
2268                         relay_thread_listener, (void *) NULL);
2269         if (ret != 0) {
2270                 PERROR("pthread_create listener");
2271                 goto exit_listener;
2272         }
2273
2274 exit_listener:
2275         ret = pthread_join(listener_thread, &status);
2276         if (ret != 0) {
2277                 PERROR("pthread_join");
2278                 goto error;     /* join error, exit without cleanup */
2279         }
2280
2281 exit_worker:
2282         ret = pthread_join(worker_thread, &status);
2283         if (ret != 0) {
2284                 PERROR("pthread_join");
2285                 goto error;     /* join error, exit without cleanup */
2286         }
2287
2288 exit_dispatcher:
2289         ret = pthread_join(dispatcher_thread, &status);
2290         if (ret != 0) {
2291                 PERROR("pthread_join");
2292                 goto error;     /* join error, exit without cleanup */
2293         }
2294
2295 exit:
2296         cleanup();
2297         if (!ret) {
2298                 exit(EXIT_SUCCESS);
2299         }
2300
2301 error:
2302         exit(EXIT_FAILURE);
2303 }