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) {
 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                 nb_fd = LTTNG_POLL_GETNB(&events);
 518
 519 restart:
 520                 ret = lttng_poll_wait(&events, -1);
 521                 if (ret < 0) {
 522                         /*
 523                          * Restart interrupted system call.
 524                          */
 525                         if (errno == EINTR) {
 526                                 goto restart;
 527                         }
 528                         goto error;
 529                 }
 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) {
 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 static
 870 void deferred_free_stream(struct rcu_head *head)
 871 {
 872         struct relay_stream *stream =
 873                 caa_container_of(head, struct relay_stream, rcu_node);
 874         free(stream);
 875 }
 876
 877 /*
 878  * relay_delete_session: Free all memory associated with a session and
 879  * close all the FDs
 880  */
 881 static
 882 void relay_delete_session(struct relay_command *cmd, struct lttng_ht *streams_ht)
 883 {
 884         struct lttng_ht_iter iter;
 885         struct lttng_ht_node_ulong *node;
 886         struct relay_stream *stream;
 887         int ret;
 888
 889         if (!cmd->session) {
 890                 return;
 891         }
 892
 893         DBG("Relay deleting session %" PRIu64, cmd->session->id);
 894
 895         rcu_read_lock();
 896         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, node, node) {
 897                 node = lttng_ht_iter_get_node_ulong(&iter);
 898                 if (node) {
 899                         stream = caa_container_of(node,
 900                                         struct relay_stream, stream_n);
 901                         if (stream->session == cmd->session) {
 902                                 ret = close(stream->fd);
 903                                 if (ret < 0) {
 904                                         PERROR("close stream fd on delete session");
 905                                 }
 906                                 ret = lttng_ht_del(streams_ht, &iter);
 907                                 assert(!ret);
 908                                 call_rcu(&stream->rcu_node,
 909                                         deferred_free_stream);
 910                         }
 911                 }
 912         }
 913         rcu_read_unlock();
 914
 915         free(cmd->session);
 916 }
 917
 918 /*
 919  * Handle the RELAYD_CREATE_SESSION command.
 920  *
 921  * On success, send back the session id or else return a negative value.
 922  */
 923 static
 924 int relay_create_session(struct lttcomm_relayd_hdr *recv_hdr,
 925                 struct relay_command *cmd)
 926 {
 927         int ret = 0, send_ret;
 928         struct relay_session *session;
 929         struct lttcomm_relayd_status_session reply;
 930
 931         assert(recv_hdr);
 932         assert(cmd);
 933
 934         memset(&reply, 0, sizeof(reply));
 935
 936         session = zmalloc(sizeof(struct relay_session));
 937         if (session == NULL) {
 938                 PERROR("relay session zmalloc");
 939                 ret = -1;
 940                 goto error;
 941         }
 942
 943         session->id = ++last_relay_session_id;
 944         session->sock = cmd->sock;
 945         cmd->session = session;
 946
 947         reply.session_id = htobe64(session->id);
 948
 949         DBG("Created session %" PRIu64, session->id);
 950
 951 error:
 952         if (ret < 0) {
 953                 reply.ret_code = htobe32(LTTNG_ERR_FATAL);
 954         } else {
 955                 reply.ret_code = htobe32(LTTNG_OK);
 956         }
 957
 958         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
 959         if (send_ret < 0) {
 960                 ERR("Relayd sending session id");
 961         }
 962
 963         return ret;
 964 }
 965
 966 /*
 967  * relay_add_stream: allocate a new stream for a session
 968  */
 969 static
 970 int relay_add_stream(struct lttcomm_relayd_hdr *recv_hdr,
 971                 struct relay_command *cmd, struct lttng_ht *streams_ht)
 972 {
 973         struct relay_session *session = cmd->session;
 974         struct lttcomm_relayd_add_stream stream_info;
 975         struct relay_stream *stream = NULL;
 976         struct lttcomm_relayd_status_stream reply;
 977         char *path = NULL, *root_path = NULL;
 978         int ret, send_ret;
 979
 980         if (!session || cmd->version_check_done == 0) {
 981                 ERR("Trying to add a stream before version check");
 982                 ret = -1;
 983                 goto end_no_session;
 984         }
 985
 986         /* FIXME : use data_size for something ? */
 987         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
 988                         sizeof(struct lttcomm_relayd_add_stream), 0);
 989         if (ret < sizeof(struct lttcomm_relayd_add_stream)) {
 990                 ERR("Relay didn't receive valid add_stream struct size : %d", ret);
 991                 ret = -1;
 992                 goto end_no_session;
 993         }
 994         stream = zmalloc(sizeof(struct relay_stream));
 995         if (stream == NULL) {
 996                 PERROR("relay stream zmalloc");
 997                 ret = -1;
 998                 goto end_no_session;
 999         }
1000
1001         rcu_read_lock();
1002         stream->stream_handle = ++last_relay_stream_id;
1003         stream->prev_seq = -1ULL;
1004         stream->session = session;
1005
1006         root_path = create_output_path(stream_info.pathname);
1007         if (!root_path) {
1008                 ret = -1;
1009                 goto end;
1010         }
1011         ret = mkdir_recursive(root_path, S_IRWXU | S_IRWXG);
1012         if (ret < 0) {
1013                 ERR("relay creating output directory");
1014                 goto end;
1015         }
1016
1017         ret = asprintf(&path, "%s/%s", root_path, stream_info.channel_name);
1018         if (ret < 0) {
1019                 PERROR("asprintf stream path");
1020                 goto end;
1021         }
1022
1023         ret = open(path, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
1024         if (ret < 0) {
1025                 PERROR("Relay creating trace file");
1026                 goto end;
1027         }
1028
1029         stream->fd = ret;
1030         DBG("Tracefile %s created", path);
1031
1032         lttng_ht_node_init_ulong(&stream->stream_n,
1033                         (unsigned long) stream->stream_handle);
1034         lttng_ht_add_unique_ulong(streams_ht,
1035                         &stream->stream_n);
1036
1037         DBG("Relay new stream added %s", stream_info.channel_name);
1038
1039 end:
1040         free(path);
1041         free(root_path);
1042         /* send the session id to the client or a negative return code on error */
1043         if (ret < 0) {
1044                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1045         } else {
1046                 reply.ret_code = htobe32(LTTNG_OK);
1047         }
1048         reply.handle = htobe64(stream->stream_handle);
1049         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1050                         sizeof(struct lttcomm_relayd_status_stream), 0);
1051         if (send_ret < 0) {
1052                 ERR("Relay sending stream id");
1053         }
1054         rcu_read_unlock();
1055
1056 end_no_session:
1057         return ret;
1058 }
1059
1060 /*
1061  * relay_close_stream: close a specific stream
1062  */
1063 static
1064 int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
1065                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1066 {
1067         struct relay_session *session = cmd->session;
1068         struct lttcomm_relayd_close_stream stream_info;
1069         struct lttcomm_relayd_generic_reply reply;
1070         struct relay_stream *stream;
1071         int ret, send_ret;
1072         struct lttng_ht_node_ulong *node;
1073         struct lttng_ht_iter iter;
1074
1075         DBG("Close stream received");
1076
1077         if (!session || cmd->version_check_done == 0) {
1078                 ERR("Trying to close a stream before version check");
1079                 ret = -1;
1080                 goto end_no_session;
1081         }
1082
1083         ret = cmd->sock->ops->recvmsg(cmd->sock, &stream_info,
1084                         sizeof(struct lttcomm_relayd_close_stream), 0);
1085         if (ret < sizeof(struct lttcomm_relayd_close_stream)) {
1086                 ERR("Relay didn't receive valid add_stream struct size : %d", ret);
1087                 ret = -1;
1088                 goto end_no_session;
1089         }
1090
1091         rcu_read_lock();
1092         lttng_ht_lookup(streams_ht,
1093                         (void *)((unsigned long) be64toh(stream_info.stream_id)),
1094                         &iter);
1095         node = lttng_ht_iter_get_node_ulong(&iter);
1096         if (node == NULL) {
1097                 DBG("Relay stream %" PRIu64 " not found", be64toh(stream_info.stream_id));
1098                 ret = -1;
1099                 goto end_unlock;
1100         }
1101
1102         stream = caa_container_of(node, struct relay_stream, stream_n);
1103         if (!stream) {
1104                 ret = -1;
1105                 goto end_unlock;
1106         }
1107
1108         stream->last_net_seq_num = be64toh(stream_info.last_net_seq_num);
1109         stream->close_flag = 1;
1110
1111         if (close_stream_check(stream)) {
1112                 int delret;
1113
1114                 delret = close(stream->fd);
1115                 if (delret < 0) {
1116                         PERROR("close stream");
1117                 }
1118                 delret = lttng_ht_del(streams_ht, &iter);
1119                 assert(!delret);
1120                 call_rcu(&stream->rcu_node,
1121                                 deferred_free_stream);
1122                 DBG("Closed tracefile %d from close stream", stream->fd);
1123         }
1124
1125 end_unlock:
1126         rcu_read_unlock();
1127
1128         if (ret < 0) {
1129                 reply.ret_code = htobe32(LTTNG_ERR_UNK);
1130         } else {
1131                 reply.ret_code = htobe32(LTTNG_OK);
1132         }
1133         send_ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1134                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1135         if (send_ret < 0) {
1136                 ERR("Relay sending stream id");
1137         }
1138
1139 end_no_session:
1140         return ret;
1141 }
1142
1143 /*
1144  * relay_unknown_command: send -1 if received unknown command
1145  */
1146 static
1147 void relay_unknown_command(struct relay_command *cmd)
1148 {
1149         struct lttcomm_relayd_generic_reply reply;
1150         int ret;
1151
1152         reply.ret_code = htobe32(LTTNG_ERR_UNK);
1153         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1154                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1155         if (ret < 0) {
1156                 ERR("Relay sending unknown command");
1157         }
1158 }
1159
1160 /*
1161  * relay_start: send an acknowledgment to the client to tell if we are
1162  * ready to receive data. We are ready if a session is established.
1163  */
1164 static
1165 int relay_start(struct lttcomm_relayd_hdr *recv_hdr,
1166                 struct relay_command *cmd)
1167 {
1168         int ret = htobe32(LTTNG_OK);
1169         struct lttcomm_relayd_generic_reply reply;
1170         struct relay_session *session = cmd->session;
1171
1172         if (!session) {
1173                 DBG("Trying to start the streaming without a session established");
1174                 ret = htobe32(LTTNG_ERR_UNK);
1175         }
1176
1177         reply.ret_code = ret;
1178         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1179                         sizeof(struct lttcomm_relayd_generic_reply), 0);
1180         if (ret < 0) {
1181                 ERR("Relay sending start ack");
1182         }
1183
1184         return ret;
1185 }
1186
1187 /*
1188  * Get stream from stream id.
1189  * Need to be called with RCU read-side lock held.
1190  */
1191 static
1192 struct relay_stream *relay_stream_from_stream_id(uint64_t stream_id,
1193                 struct lttng_ht *streams_ht)
1194 {
1195         struct lttng_ht_node_ulong *node;
1196         struct lttng_ht_iter iter;
1197         struct relay_stream *ret;
1198
1199         lttng_ht_lookup(streams_ht,
1200                         (void *)((unsigned long) stream_id),
1201                         &iter);
1202         node = lttng_ht_iter_get_node_ulong(&iter);
1203         if (node == NULL) {
1204                 DBG("Relay stream %" PRIu64 " not found", stream_id);
1205                 ret = NULL;
1206                 goto end;
1207         }
1208
1209         ret = caa_container_of(node, struct relay_stream, stream_n);
1210
1211 end:
1212         return ret;
1213 }
1214
1215 /*
1216  * Append padding to the file pointed by the file descriptor fd.
1217  */
1218 static int write_padding_to_file(int fd, uint32_t size)
1219 {
1220         int ret = 0;
1221         char *zeros;
1222
1223         if (size == 0) {
1224                 goto end;
1225         }
1226
1227         zeros = zmalloc(size);
1228         if (zeros == NULL) {
1229                 PERROR("zmalloc zeros for padding");
1230                 ret = -1;
1231                 goto end;
1232         }
1233
1234         do {
1235                 ret = write(fd, zeros, size);
1236         } while (ret < 0 && errno == EINTR);
1237         if (ret < 0) {
1238                 PERROR("write padding to file");
1239         }
1240
1241         free(zeros);
1242
1243 end:
1244         return ret;
1245 }
1246
1247 /*
1248  * relay_recv_metadata: receive the metada for the session.
1249  */
1250 static
1251 int relay_recv_metadata(struct lttcomm_relayd_hdr *recv_hdr,
1252                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1253 {
1254         int ret = htobe32(LTTNG_OK);
1255         struct relay_session *session = cmd->session;
1256         struct lttcomm_relayd_metadata_payload *metadata_struct;
1257         struct relay_stream *metadata_stream;
1258         uint64_t data_size, payload_size;
1259
1260         if (!session) {
1261                 ERR("Metadata sent before version check");
1262                 ret = -1;
1263                 goto end;
1264         }
1265
1266         data_size = payload_size = be64toh(recv_hdr->data_size);
1267         if (data_size < sizeof(struct lttcomm_relayd_metadata_payload)) {
1268                 ERR("Incorrect data size");
1269                 ret = -1;
1270                 goto end;
1271         }
1272         payload_size -= sizeof(struct lttcomm_relayd_metadata_payload);
1273
1274         if (data_buffer_size < data_size) {
1275                 /* In case the realloc fails, we can free the memory */
1276                 char *tmp_data_ptr = data_buffer;
1277                 data_buffer = realloc(data_buffer, data_size);
1278                 if (!data_buffer) {
1279                         ERR("Allocating data buffer");
1280                         free(tmp_data_ptr);
1281                         ret = -1;
1282                         goto end;
1283                 }
1284                 data_buffer_size = data_size;
1285         }
1286         memset(data_buffer, 0, data_size);
1287         DBG2("Relay receiving metadata, waiting for %" PRIu64 " bytes", data_size);
1288         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1289         if (ret < 0 || ret != data_size) {
1290                 ret = -1;
1291                 ERR("Relay didn't receive the whole metadata");
1292                 goto end;
1293         }
1294         metadata_struct = (struct lttcomm_relayd_metadata_payload *) data_buffer;
1295
1296         rcu_read_lock();
1297         metadata_stream = relay_stream_from_stream_id(
1298                         be64toh(metadata_struct->stream_id), streams_ht);
1299         if (!metadata_stream) {
1300                 ret = -1;
1301                 goto end_unlock;
1302         }
1303
1304         do {
1305                 ret = write(metadata_stream->fd, metadata_struct->payload,
1306                                 payload_size);
1307         } while (ret < 0 && errno == EINTR);
1308         if (ret < payload_size) {
1309                 ERR("Relay error writing metadata on file");
1310                 ret = -1;
1311                 goto end_unlock;
1312         }
1313
1314         ret = write_padding_to_file(metadata_stream->fd,
1315                         be32toh(metadata_struct->padding_size));
1316         if (ret < 0) {
1317                 goto end_unlock;
1318         }
1319
1320         DBG2("Relay metadata written");
1321
1322 end_unlock:
1323         rcu_read_unlock();
1324 end:
1325         return ret;
1326 }
1327
1328 /*
1329  * relay_send_version: send relayd version number
1330  */
1331 static
1332 int relay_send_version(struct lttcomm_relayd_hdr *recv_hdr,
1333                 struct relay_command *cmd)
1334 {
1335         int ret;
1336         struct lttcomm_relayd_version reply, msg;
1337
1338         assert(cmd);
1339
1340         cmd->version_check_done = 1;
1341
1342         /* Get version from the other side. */
1343         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1344         if (ret < 0 || ret != sizeof(msg)) {
1345                 ret = -1;
1346                 ERR("Relay failed to receive the version values.");
1347                 goto end;
1348         }
1349
1350         /*
1351          * For now, we just ignore the received version but after 2.1 stable
1352          * release, a check must be done to see if we either adapt to the other
1353          * side version (which MUST be lower than us) or keep the latest data
1354          * structure considering that the other side will adapt.
1355          */
1356
1357         ret = sscanf(VERSION, "%u.%u", &reply.major, &reply.minor);
1358         if (ret < 2) {
1359                 ERR("Error in scanning version");
1360                 ret = -1;
1361                 goto end;
1362         }
1363         reply.major = htobe32(reply.major);
1364         reply.minor = htobe32(reply.minor);
1365         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply,
1366                         sizeof(struct lttcomm_relayd_version), 0);
1367         if (ret < 0) {
1368                 ERR("Relay sending version");
1369         }
1370         DBG("Version check done (%u.%u)", be32toh(reply.major),
1371                         be32toh(reply.minor));
1372
1373 end:
1374         return ret;
1375 }
1376
1377 /*
1378  * Check for data pending for a given stream id from the session daemon.
1379  */
1380 static
1381 int relay_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1382                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1383 {
1384         struct relay_session *session = cmd->session;
1385         struct lttcomm_relayd_data_pending msg;
1386         struct lttcomm_relayd_generic_reply reply;
1387         struct relay_stream *stream;
1388         int ret;
1389         struct lttng_ht_node_ulong *node;
1390         struct lttng_ht_iter iter;
1391         uint64_t last_net_seq_num, stream_id;
1392
1393         DBG("Data pending command received");
1394
1395         if (!session || cmd->version_check_done == 0) {
1396                 ERR("Trying to check for data before version check");
1397                 ret = -1;
1398                 goto end_no_session;
1399         }
1400
1401         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1402         if (ret < sizeof(msg)) {
1403                 ERR("Relay didn't receive valid data_pending struct size : %d", ret);
1404                 ret = -1;
1405                 goto end_no_session;
1406         }
1407
1408         stream_id = be64toh(msg.stream_id);
1409         last_net_seq_num = be64toh(msg.last_net_seq_num);
1410
1411         rcu_read_lock();
1412         lttng_ht_lookup(streams_ht, (void *)((unsigned long) stream_id), &iter);
1413         node = lttng_ht_iter_get_node_ulong(&iter);
1414         if (node == NULL) {
1415                 DBG("Relay stream %" PRIu64 " not found", stream_id);
1416                 ret = -1;
1417                 goto end_unlock;
1418         }
1419
1420         stream = caa_container_of(node, struct relay_stream, stream_n);
1421         assert(stream);
1422
1423         DBG("Data pending for stream id %" PRIu64 " prev_seq %" PRIu64
1424                         " and last_seq %" PRIu64, stream_id, stream->prev_seq,
1425                         last_net_seq_num);
1426
1427         /* Avoid wrapping issue */
1428         if (((int64_t) (stream->prev_seq - last_net_seq_num)) <= 0) {
1429                 /* Data has in fact been written and is NOT pending */
1430                 ret = 0;
1431         } else {
1432                 /* Data still being streamed thus pending */
1433                 ret = 1;
1434         }
1435
1436         /* Pending check is now done. */
1437         stream->data_pending_check_done = 1;
1438
1439 end_unlock:
1440         rcu_read_unlock();
1441
1442         reply.ret_code = htobe32(ret);
1443         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1444         if (ret < 0) {
1445                 ERR("Relay data pending ret code failed");
1446         }
1447
1448 end_no_session:
1449         return ret;
1450 }
1451
1452 /*
1453  * Wait for the control socket to reach a quiescent state.
1454  *
1455  * Note that for now, when receiving this command from the session daemon, this
1456  * means that every subsequent commands or data received on the control socket
1457  * has been handled. So, this is why we simply return OK here.
1458  */
1459 static
1460 int relay_quiescent_control(struct lttcomm_relayd_hdr *recv_hdr,
1461                 struct relay_command *cmd)
1462 {
1463         int ret;
1464         struct lttcomm_relayd_generic_reply reply;
1465
1466         DBG("Checking quiescent state on control socket");
1467
1468         reply.ret_code = htobe32(LTTNG_OK);
1469         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1470         if (ret < 0) {
1471                 ERR("Relay data quiescent control ret code failed");
1472         }
1473
1474         return ret;
1475 }
1476
1477 /*
1478  * Initialize a data pending command. This means that a client is about to ask
1479  * for data pending for each stream he/she holds. Simply iterate over all
1480  * streams of a session and set the data_pending_check_done flag.
1481  *
1482  * This command returns to the client a LTTNG_OK code.
1483  */
1484 static
1485 int relay_begin_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1486                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1487 {
1488         int ret;
1489         struct lttng_ht_iter iter;
1490         struct lttcomm_relayd_begin_data_pending msg;
1491         struct lttcomm_relayd_generic_reply reply;
1492         struct relay_stream *stream;
1493         uint64_t session_id;
1494
1495         assert(recv_hdr);
1496         assert(cmd);
1497         assert(streams_ht);
1498
1499         DBG("Init streams for data pending");
1500
1501         if (!cmd->session || cmd->version_check_done == 0) {
1502                 ERR("Trying to check for data before version check");
1503                 ret = -1;
1504                 goto end_no_session;
1505         }
1506
1507         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1508         if (ret < sizeof(msg)) {
1509                 ERR("Relay didn't receive valid begin data_pending struct size: %d",
1510                                 ret);
1511                 ret = -1;
1512                 goto end_no_session;
1513         }
1514
1515         session_id = be64toh(msg.session_id);
1516
1517         /*
1518          * Iterate over all streams to set the begin data pending flag. For now, the
1519          * streams are indexed by stream handle so we have to iterate over all
1520          * streams to find the one associated with the right session_id.
1521          */
1522         rcu_read_lock();
1523         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1524                 if (stream->session->id == session_id) {
1525                         stream->data_pending_check_done = 0;
1526                         DBG("Set begin data pending flag to stream %" PRIu64,
1527                                         stream->stream_handle);
1528                 }
1529         }
1530         rcu_read_unlock();
1531
1532         /* All good, send back reply. */
1533         reply.ret_code = htobe32(LTTNG_OK);
1534
1535         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1536         if (ret < 0) {
1537                 ERR("Relay begin data pending send reply failed");
1538         }
1539
1540 end_no_session:
1541         return ret;
1542 }
1543
1544 /*
1545  * End data pending command. This will check, for a given session id, if each
1546  * stream associated with it has its data_pending_check_done flag set. If not,
1547  * this means that the client lost track of the stream but the data is still
1548  * being streamed on our side. In this case, we inform the client that data is
1549  * inflight.
1550  *
1551  * Return to the client if there is data in flight or not with a ret_code.
1552  */
1553 static
1554 int relay_end_data_pending(struct lttcomm_relayd_hdr *recv_hdr,
1555                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1556 {
1557         int ret;
1558         struct lttng_ht_iter iter;
1559         struct lttcomm_relayd_end_data_pending msg;
1560         struct lttcomm_relayd_generic_reply reply;
1561         struct relay_stream *stream;
1562         uint64_t session_id;
1563         uint32_t is_data_inflight = 0;
1564
1565         assert(recv_hdr);
1566         assert(cmd);
1567         assert(streams_ht);
1568
1569         DBG("End data pending command");
1570
1571         if (!cmd->session || cmd->version_check_done == 0) {
1572                 ERR("Trying to check for data before version check");
1573                 ret = -1;
1574                 goto end_no_session;
1575         }
1576
1577         ret = cmd->sock->ops->recvmsg(cmd->sock, &msg, sizeof(msg), 0);
1578         if (ret < sizeof(msg)) {
1579                 ERR("Relay didn't receive valid end data_pending struct size: %d",
1580                                 ret);
1581                 ret = -1;
1582                 goto end_no_session;
1583         }
1584
1585         session_id = be64toh(msg.session_id);
1586
1587         /* Iterate over all streams to see if the begin data pending flag is set. */
1588         rcu_read_lock();
1589         cds_lfht_for_each_entry(streams_ht->ht, &iter.iter, stream, stream_n.node) {
1590                 if (stream->session->id == session_id &&
1591                                 !stream->data_pending_check_done) {
1592                         is_data_inflight = 1;
1593                         DBG("Data is still in flight for stream %" PRIu64,
1594                                         stream->stream_handle);
1595                         break;
1596                 }
1597         }
1598         rcu_read_unlock();
1599
1600         /* All good, send back reply. */
1601         reply.ret_code = htobe32(is_data_inflight);
1602
1603         ret = cmd->sock->ops->sendmsg(cmd->sock, &reply, sizeof(reply), 0);
1604         if (ret < 0) {
1605                 ERR("Relay end data pending send reply failed");
1606         }
1607
1608 end_no_session:
1609         return ret;
1610 }
1611
1612 /*
1613  * relay_process_control: Process the commands received on the control socket
1614  */
1615 static
1616 int relay_process_control(struct lttcomm_relayd_hdr *recv_hdr,
1617                 struct relay_command *cmd, struct lttng_ht *streams_ht)
1618 {
1619         int ret = 0;
1620
1621         switch (be32toh(recv_hdr->cmd)) {
1622         case RELAYD_CREATE_SESSION:
1623                 ret = relay_create_session(recv_hdr, cmd);
1624                 break;
1625         case RELAYD_ADD_STREAM:
1626                 ret = relay_add_stream(recv_hdr, cmd, streams_ht);
1627                 break;
1628         case RELAYD_START_DATA:
1629                 ret = relay_start(recv_hdr, cmd);
1630                 break;
1631         case RELAYD_SEND_METADATA:
1632                 ret = relay_recv_metadata(recv_hdr, cmd, streams_ht);
1633                 break;
1634         case RELAYD_VERSION:
1635                 ret = relay_send_version(recv_hdr, cmd);
1636                 break;
1637         case RELAYD_CLOSE_STREAM:
1638                 ret = relay_close_stream(recv_hdr, cmd, streams_ht);
1639                 break;
1640         case RELAYD_DATA_PENDING:
1641                 ret = relay_data_pending(recv_hdr, cmd, streams_ht);
1642                 break;
1643         case RELAYD_QUIESCENT_CONTROL:
1644                 ret = relay_quiescent_control(recv_hdr, cmd);
1645                 break;
1646         case RELAYD_BEGIN_DATA_PENDING:
1647                 ret = relay_begin_data_pending(recv_hdr, cmd, streams_ht);
1648                 break;
1649         case RELAYD_END_DATA_PENDING:
1650                 ret = relay_end_data_pending(recv_hdr, cmd, streams_ht);
1651                 break;
1652         case RELAYD_UPDATE_SYNC_INFO:
1653         default:
1654                 ERR("Received unknown command (%u)", be32toh(recv_hdr->cmd));
1655                 relay_unknown_command(cmd);
1656                 ret = -1;
1657                 goto end;
1658         }
1659
1660 end:
1661         return ret;
1662 }
1663
1664 /*
1665  * relay_process_data: Process the data received on the data socket
1666  */
1667 static
1668 int relay_process_data(struct relay_command *cmd, struct lttng_ht *streams_ht)
1669 {
1670         int ret = 0;
1671         struct relay_stream *stream;
1672         struct lttcomm_relayd_data_hdr data_hdr;
1673         uint64_t stream_id;
1674         uint64_t net_seq_num;
1675         uint32_t data_size;
1676
1677         ret = cmd->sock->ops->recvmsg(cmd->sock, &data_hdr,
1678                         sizeof(struct lttcomm_relayd_data_hdr), 0);
1679         if (ret <= 0) {
1680                 ERR("Connections seems to be closed");
1681                 ret = -1;
1682                 goto end;
1683         }
1684
1685         stream_id = be64toh(data_hdr.stream_id);
1686
1687         rcu_read_lock();
1688         stream = relay_stream_from_stream_id(stream_id, streams_ht);
1689         if (!stream) {
1690                 ret = -1;
1691                 goto end_unlock;
1692         }
1693
1694         data_size = be32toh(data_hdr.data_size);
1695         if (data_buffer_size < data_size) {
1696                 char *tmp_data_ptr = data_buffer;
1697                 data_buffer = realloc(data_buffer, data_size);
1698                 if (!data_buffer) {
1699                         ERR("Allocating data buffer");
1700                         free(tmp_data_ptr);
1701                         ret = -1;
1702                         goto end_unlock;
1703                 }
1704                 data_buffer_size = data_size;
1705         }
1706         memset(data_buffer, 0, data_size);
1707
1708         net_seq_num = be64toh(data_hdr.net_seq_num);
1709
1710         DBG3("Receiving data of size %u for stream id %" PRIu64 " seqnum %" PRIu64,
1711                 data_size, stream_id, net_seq_num);
1712         ret = cmd->sock->ops->recvmsg(cmd->sock, data_buffer, data_size, 0);
1713         if (ret <= 0) {
1714                 ret = -1;
1715                 goto end_unlock;
1716         }
1717
1718         do {
1719                 ret = write(stream->fd, data_buffer, data_size);
1720         } while (ret < 0 && errno == EINTR);
1721         if (ret < data_size) {
1722                 ERR("Relay error writing data to file");
1723                 ret = -1;
1724                 goto end_unlock;
1725         }
1726
1727         DBG2("Relay wrote %d bytes to tracefile for stream id %" PRIu64,
1728                         ret, stream->stream_handle);
1729
1730         ret = write_padding_to_file(stream->fd, be32toh(data_hdr.padding_size));
1731         if (ret < 0) {
1732                 goto end_unlock;
1733         }
1734
1735         stream->prev_seq = net_seq_num;
1736
1737         /* Check if we need to close the FD */
1738         if (close_stream_check(stream)) {
1739                 int cret;
1740                 struct lttng_ht_iter iter;
1741
1742                 cret = close(stream->fd);
1743                 if (cret < 0) {
1744                         PERROR("close stream process data");
1745                 }
1746                 iter.iter.node = &stream->stream_n.node;
1747                 ret = lttng_ht_del(streams_ht, &iter);
1748                 assert(!ret);
1749                 call_rcu(&stream->rcu_node,
1750                         deferred_free_stream);
1751                 DBG("Closed tracefile %d after recv data", stream->fd);
1752         }
1753
1754 end_unlock:
1755         rcu_read_unlock();
1756 end:
1757         return ret;
1758 }
1759
1760 static
1761 void relay_cleanup_poll_connection(struct lttng_poll_event *events, int pollfd)
1762 {
1763         int ret;
1764
1765         lttng_poll_del(events, pollfd);
1766
1767         ret = close(pollfd);
1768         if (ret < 0) {
1769                 ERR("Closing pollfd %d", pollfd);
1770         }
1771 }
1772
1773 static
1774 int relay_add_connection(int fd, struct lttng_poll_event *events,
1775                 struct lttng_ht *relay_connections_ht)
1776 {
1777         struct relay_command *relay_connection;
1778         int ret;
1779
1780         relay_connection = zmalloc(sizeof(struct relay_command));
1781         if (relay_connection == NULL) {
1782                 PERROR("Relay command zmalloc");
1783                 goto error;
1784         }
1785         ret = read(fd, relay_connection, sizeof(struct relay_command));
1786         if (ret < 0 || ret < sizeof(struct relay_command)) {
1787                 PERROR("read relay cmd pipe");
1788                 goto error_read;
1789         }
1790
1791         lttng_ht_node_init_ulong(&relay_connection->sock_n,
1792                         (unsigned long) relay_connection->sock->fd);
1793         rcu_read_lock();
1794         lttng_ht_add_unique_ulong(relay_connections_ht,
1795                         &relay_connection->sock_n);
1796         rcu_read_unlock();
1797         return lttng_poll_add(events,
1798                         relay_connection->sock->fd,
1799                         LPOLLIN | LPOLLRDHUP);
1800
1801 error_read:
1802         free(relay_connection);
1803 error:
1804         return -1;
1805 }
1806
1807 static
1808 void deferred_free_connection(struct rcu_head *head)
1809 {
1810         struct relay_command *relay_connection =
1811                 caa_container_of(head, struct relay_command, rcu_node);
1812
1813         lttcomm_destroy_sock(relay_connection->sock);
1814         free(relay_connection);
1815 }
1816
1817 static
1818 void relay_del_connection(struct lttng_ht *relay_connections_ht,
1819                 struct lttng_ht *streams_ht, struct lttng_ht_iter *iter,
1820                 struct relay_command *relay_connection)
1821 {
1822         int ret;
1823
1824         ret = lttng_ht_del(relay_connections_ht, iter);
1825         assert(!ret);
1826         if (relay_connection->type == RELAY_CONTROL) {
1827                 relay_delete_session(relay_connection, streams_ht);
1828         }
1829
1830         call_rcu(&relay_connection->rcu_node,
1831                 deferred_free_connection);
1832 }
1833
1834 /*
1835  * This thread does the actual work
1836  */
1837 static
1838 void *relay_thread_worker(void *data)
1839 {
1840         int i, ret, pollfd, err = -1;
1841         uint32_t revents, nb_fd;
1842         struct relay_command *relay_connection;
1843         struct lttng_poll_event events;
1844         struct lttng_ht *relay_connections_ht;
1845         struct lttng_ht_node_ulong *node;
1846         struct lttng_ht_iter iter;
1847         struct lttng_ht *streams_ht;
1848         struct lttcomm_relayd_hdr recv_hdr;
1849
1850         DBG("[thread] Relay worker started");
1851
1852         rcu_register_thread();
1853
1854         /* table of connections indexed on socket */
1855         relay_connections_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1856         if (!relay_connections_ht) {
1857                 goto relay_connections_ht_error;
1858         }
1859
1860         /* tables of streams indexed by stream ID */
1861         streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1862         if (!streams_ht) {
1863                 goto streams_ht_error;
1864         }
1865
1866         ret = create_thread_poll_set(&events, 2);
1867         if (ret < 0) {
1868                 goto error_poll_create;
1869         }
1870
1871         ret = lttng_poll_add(&events, relay_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
1872         if (ret < 0) {
1873                 goto error;
1874         }
1875
1876         while (1) {
1877                 /* Zeroed the events structure */
1878                 lttng_poll_reset(&events);
1879
1880                 nb_fd = LTTNG_POLL_GETNB(&events);
1881
1882                 /* Infinite blocking call, waiting for transmission */
1883         restart:
1884                 DBG3("Relayd worker thread polling...");
1885                 ret = lttng_poll_wait(&events, -1);
1886                 if (ret < 0) {
1887                         /*
1888                          * Restart interrupted system call.
1889                          */
1890                         if (errno == EINTR) {
1891                                 goto restart;
1892                         }
1893                         goto error;
1894                 }
1895
1896                 for (i = 0; i < nb_fd; i++) {
1897                         /* Fetch once the poll data */
1898                         revents = LTTNG_POLL_GETEV(&events, i);
1899                         pollfd = LTTNG_POLL_GETFD(&events, i);
1900
1901                         /* Thread quit pipe has been closed. Killing thread. */
1902                         ret = check_thread_quit_pipe(pollfd, revents);
1903                         if (ret) {
1904                                 err = 0;
1905                                 goto exit;
1906                         }
1907
1908                         /* Inspect the relay cmd pipe for new connection */
1909                         if (pollfd == relay_cmd_pipe[0]) {
1910                                 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
1911                                         ERR("Relay pipe error");
1912                                         goto error;
1913                                 } else if (revents & LPOLLIN) {
1914                                         DBG("Relay command received");
1915                                         ret = relay_add_connection(relay_cmd_pipe[0],
1916                                                         &events, relay_connections_ht);
1917                                         if (ret < 0) {
1918                                                 goto error;
1919                                         }
1920                                 }
1921                         } else if (revents > 0) {
1922                                 rcu_read_lock();
1923                                 lttng_ht_lookup(relay_connections_ht,
1924                                                 (void *)((unsigned long) pollfd),
1925                                                 &iter);
1926                                 node = lttng_ht_iter_get_node_ulong(&iter);
1927                                 if (node == NULL) {
1928                                         DBG2("Relay sock %d not found", pollfd);
1929                                         rcu_read_unlock();
1930                                         goto error;
1931                                 }
1932                                 relay_connection = caa_container_of(node,
1933                                                 struct relay_command, sock_n);
1934
1935                                 if (revents & (LPOLLERR)) {
1936                                         ERR("POLL ERROR");
1937                                         relay_cleanup_poll_connection(&events, pollfd);
1938                                         relay_del_connection(relay_connections_ht,
1939                                                         streams_ht, &iter,
1940                                                         relay_connection);
1941                                 } else if (revents & (LPOLLHUP | LPOLLRDHUP)) {
1942                                         DBG("Socket %d hung up", pollfd);
1943                                         relay_cleanup_poll_connection(&events, pollfd);
1944                                         relay_del_connection(relay_connections_ht,
1945                                                         streams_ht, &iter,
1946                                                         relay_connection);
1947                                 } else if (revents & LPOLLIN) {
1948                                         /* control socket */
1949                                         if (relay_connection->type == RELAY_CONTROL) {
1950                                                 ret = relay_connection->sock->ops->recvmsg(
1951                                                                 relay_connection->sock, &recv_hdr,
1952                                                                 sizeof(struct lttcomm_relayd_hdr), 0);
1953                                                 /* connection closed */
1954                                                 if (ret <= 0) {
1955                                                         relay_cleanup_poll_connection(&events, pollfd);
1956                                                         relay_del_connection(relay_connections_ht,
1957                                                                         streams_ht, &iter,
1958                                                                         relay_connection);
1959                                                         DBG("Control connection closed with %d", pollfd);
1960                                                 } else {
1961                                                         if (relay_connection->session) {
1962                                                                 DBG2("Relay worker receiving data for session : %" PRIu64,
1963                                                                                 relay_connection->session->id);
1964                                                         }
1965                                                         ret = relay_process_control(&recv_hdr,
1966                                                                         relay_connection,
1967                                                                         streams_ht);
1968                                                         /*
1969                                                          * there was an error in processing a control
1970                                                          * command: clear the session
1971                                                          * */
1972                                                         if (ret < 0) {
1973                                                                 relay_cleanup_poll_connection(&events, pollfd);
1974                                                                 relay_del_connection(relay_connections_ht,
1975                                                                                 streams_ht, &iter,
1976                                                                                 relay_connection);
1977                                                                 DBG("Connection closed with %d", pollfd);
1978                                                         }
1979                                                 }
1980                                                 /* data socket */
1981                                         } else if (relay_connection->type == RELAY_DATA) {
1982                                                 ret = relay_process_data(relay_connection, streams_ht);
1983                                                 /* connection closed */
1984                                                 if (ret < 0) {
1985                                                         relay_cleanup_poll_connection(&events, pollfd);
1986                                                         relay_del_connection(relay_connections_ht,
1987                                                                         streams_ht, &iter,
1988                                                                         relay_connection);
1989                                                         DBG("Data connection closed with %d", pollfd);
1990                                                 }
1991                                         }
1992                                 }
1993                                 rcu_read_unlock();
1994                         }
1995                 }
1996         }
1997
1998 exit:
1999 error:
2000         lttng_poll_clean(&events);
2001
2002         /* empty the hash table and free the memory */
2003         rcu_read_lock();
2004         cds_lfht_for_each_entry(relay_connections_ht->ht, &iter.iter, node, node) {
2005                 node = lttng_ht_iter_get_node_ulong(&iter);
2006                 if (node) {
2007                         relay_connection = caa_container_of(node,
2008                                         struct relay_command, sock_n);
2009                         relay_del_connection(relay_connections_ht,
2010                                         streams_ht, &iter,
2011                                         relay_connection);
2012                 }
2013         }
2014         rcu_read_unlock();
2015 error_poll_create:
2016         lttng_ht_destroy(streams_ht);
2017 streams_ht_error:
2018         lttng_ht_destroy(relay_connections_ht);
2019 relay_connections_ht_error:
2020         /* Close relay cmd pipes */
2021         utils_close_pipe(relay_cmd_pipe);
2022         if (err) {
2023                 DBG("Thread exited with error");
2024         }
2025         DBG("Worker thread cleanup complete");
2026         free(data_buffer);
2027         stop_threads();
2028         rcu_unregister_thread();
2029         return NULL;
2030 }
2031
2032 /*
2033  * Create the relay command pipe to wake thread_manage_apps.
2034  * Closed in cleanup().
2035  */
2036 static int create_relay_cmd_pipe(void)
2037 {
2038         int ret;
2039
2040         ret = utils_create_pipe_cloexec(relay_cmd_pipe);
2041
2042         return ret;
2043 }
2044
2045 /*
2046  * main
2047  */
2048 int main(int argc, char **argv)
2049 {
2050         int ret = 0;
2051         void *status;
2052
2053         /* Create thread quit pipe */
2054         if ((ret = init_thread_quit_pipe()) < 0) {
2055                 goto error;
2056         }
2057
2058         /* Parse arguments */
2059         progname = argv[0];
2060         if ((ret = parse_args(argc, argv) < 0)) {
2061                 goto exit;
2062         }
2063
2064         if ((ret = set_signal_handler()) < 0) {
2065                 goto exit;
2066         }
2067
2068         /* Daemonize */
2069         if (opt_daemon) {
2070                 ret = daemon(0, 0);
2071                 if (ret < 0) {
2072                         PERROR("daemon");
2073                         goto exit;
2074                 }
2075         }
2076
2077         /* Check if daemon is UID = 0 */
2078         is_root = !getuid();
2079
2080         if (!is_root) {
2081                 if (control_uri->port < 1024 || data_uri->port < 1024) {
2082                         ERR("Need to be root to use ports < 1024");
2083                         ret = -1;
2084                         goto exit;
2085                 }
2086         }
2087
2088         /* Setup the thread apps communication pipe. */
2089         if ((ret = create_relay_cmd_pipe()) < 0) {
2090                 goto exit;
2091         }
2092
2093         /* Init relay command queue. */
2094         cds_wfq_init(&relay_cmd_queue.queue);
2095
2096         /* Set up max poll set size */
2097         lttng_poll_set_max_size();
2098
2099         /* Setup the dispatcher thread */
2100         ret = pthread_create(&dispatcher_thread, NULL,
2101                         relay_thread_dispatcher, (void *) NULL);
2102         if (ret != 0) {
2103                 PERROR("pthread_create dispatcher");
2104                 goto exit_dispatcher;
2105         }
2106
2107         /* Setup the worker thread */
2108         ret = pthread_create(&worker_thread, NULL,
2109                         relay_thread_worker, (void *) NULL);
2110         if (ret != 0) {
2111                 PERROR("pthread_create worker");
2112                 goto exit_worker;
2113         }
2114
2115         /* Setup the listener thread */
2116         ret = pthread_create(&listener_thread, NULL,
2117                         relay_thread_listener, (void *) NULL);
2118         if (ret != 0) {
2119                 PERROR("pthread_create listener");
2120                 goto exit_listener;
2121         }
2122
2123 exit_listener:
2124         ret = pthread_join(listener_thread, &status);
2125         if (ret != 0) {
2126                 PERROR("pthread_join");
2127                 goto error;     /* join error, exit without cleanup */
2128         }
2129
2130 exit_worker:
2131         ret = pthread_join(worker_thread, &status);
2132         if (ret != 0) {
2133                 PERROR("pthread_join");
2134                 goto error;     /* join error, exit without cleanup */
2135         }
2136
2137 exit_dispatcher:
2138         ret = pthread_join(dispatcher_thread, &status);
2139         if (ret != 0) {
2140                 PERROR("pthread_join");
2141                 goto error;     /* join error, exit without cleanup */
2142         }
2143
2144 exit:
2145         cleanup();
2146         if (!ret) {
2147                 exit(EXIT_SUCCESS);
2148         }
2149
2150 error:
2151         exit(EXIT_FAILURE);
2152 }