src/bin/lttng-consumerd/lttng-consumerd.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@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,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for 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 _LGPL_SOURCE
  20 #include <fcntl.h>
  21 #include <getopt.h>
  22 #include <grp.h>
  23 #include <limits.h>
  24 #include <pthread.h>
  25 #include <signal.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/ipc.h>
  30 #include <sys/resource.h>
  31 #include <sys/shm.h>
  32 #include <sys/socket.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <urcu/list.h>
  36 #include <poll.h>
  37 #include <unistd.h>
  38 #include <sys/mman.h>
  39 #include <assert.h>
  40 #include <urcu/compiler.h>
  41 #include <ulimit.h>
  42
  43 #include <common/defaults.h>
  44 #include <common/common.h>
  45 #include <common/consumer/consumer.h>
  46 #include <common/consumer/consumer-timer.h>
  47 #include <common/compat/poll.h>
  48 #include <common/compat/getenv.h>
  49 #include <common/sessiond-comm/sessiond-comm.h>
  50 #include <common/utils.h>
  51
  52 #include "lttng-consumerd.h"
  53 #include "health-consumerd.h"
  54
  55 /* threads (channel handling, poll, metadata, sessiond) */
  56
  57 static pthread_t channel_thread, data_thread, metadata_thread,
  58                 sessiond_thread, metadata_timer_thread, health_thread;
  59 static bool metadata_timer_thread_online;
  60
  61 /* to count the number of times the user pressed ctrl+c */
  62 static int sigintcount = 0;
  63
  64 /* Argument variables */
  65 int lttng_opt_quiet;    /* not static in error.h */
  66 int lttng_opt_verbose;  /* not static in error.h */
  67 int lttng_opt_mi;       /* not static in error.h */
  68
  69 static int opt_daemon;
  70 static const char *progname;
  71 static char command_sock_path[PATH_MAX]; /* Global command socket path */
  72 static char error_sock_path[PATH_MAX]; /* Global error path */
  73 static enum lttng_consumer_type opt_type = LTTNG_CONSUMER_KERNEL;
  74
  75 /* the liblttngconsumerd context */
  76 static struct lttng_consumer_local_data *ctx;
  77
  78 /* Consumerd health monitoring */
  79 struct health_app *health_consumerd;
  80
  81 const char *tracing_group_name = DEFAULT_TRACING_GROUP;
  82
  83 int lttng_consumer_ready = NR_LTTNG_CONSUMER_READY;
  84
  85 enum lttng_consumer_type lttng_consumer_get_type(void)
  86 {
  87         if (!ctx) {
  88                 return LTTNG_CONSUMER_UNKNOWN;
  89         }
  90         return ctx->type;
  91 }
  92
  93 /*
  94  * Signal handler for the daemon
  95  */
  96 static void sighandler(int sig)
  97 {
  98         if (sig == SIGINT && sigintcount++ == 0) {
  99                 DBG("ignoring first SIGINT");
 100                 return;
 101         }
 102
 103         if (ctx) {
 104                 lttng_consumer_should_exit(ctx);
 105         }
 106 }
 107
 108 /*
 109  * Setup signal handler for :
 110  *      SIGINT, SIGTERM, SIGPIPE
 111  */
 112 static int set_signal_handler(void)
 113 {
 114         int ret = 0;
 115         struct sigaction sa;
 116         sigset_t sigset;
 117
 118         if ((ret = sigemptyset(&sigset)) < 0) {
 119                 PERROR("sigemptyset");
 120                 return ret;
 121         }
 122
 123         sa.sa_mask = sigset;
 124         sa.sa_flags = 0;
 125
 126         sa.sa_handler = sighandler;
 127         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 128                 PERROR("sigaction");
 129                 return ret;
 130         }
 131
 132         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 133                 PERROR("sigaction");
 134                 return ret;
 135         }
 136
 137         sa.sa_handler = SIG_IGN;
 138         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 139                 PERROR("sigaction");
 140                 return ret;
 141         }
 142
 143         return ret;
 144 }
 145
 146 /*
 147  * Usage function on stream file.
 148  */
 149 static void usage(FILE *fp)
 150 {
 151         fprintf(fp, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 152         fprintf(fp, "  -h, --help                         "
 153                         "Display this usage.\n");
 154         fprintf(fp, "  -c, --consumerd-cmd-sock PATH      "
 155                         "Specify path for the command socket\n");
 156         fprintf(fp, "  -e, --consumerd-err-sock PATH      "
 157                         "Specify path for the error socket\n");
 158         fprintf(fp, "  -d, --daemonize                    "
 159                         "Start as a daemon.\n");
 160         fprintf(fp, "  -q, --quiet                        "
 161                         "No output at all.\n");
 162         fprintf(fp, "  -v, --verbose                      "
 163                         "Verbose mode. Activate DBG() macro.\n");
 164         fprintf(fp, "  -V, --version                      "
 165                         "Show version number.\n");
 166         fprintf(fp, "  -g, --group NAME                   "
 167                         "Specify the tracing group name. (default: tracing)\n");
 168         fprintf(fp, "  -k, --kernel                       "
 169                         "Consumer kernel buffers (default).\n");
 170         fprintf(fp, "  -u, --ust                          "
 171                         "Consumer UST buffers.%s\n",
 172 #ifdef HAVE_LIBLTTNG_UST_CTL
 173                         ""
 174 #else
 175                         " (support not compiled in)"
 176 #endif
 177                         );
 178 }
 179
 180 /*
 181  * daemon argument parsing
 182  */
 183 static int parse_args(int argc, char **argv)
 184 {
 185         int c, ret = 0;
 186
 187         static struct option long_options[] = {
 188                 { "consumerd-cmd-sock", 1, 0, 'c' },
 189                 { "consumerd-err-sock", 1, 0, 'e' },
 190                 { "daemonize", 0, 0, 'd' },
 191                 { "group", 1, 0, 'g' },
 192                 { "help", 0, 0, 'h' },
 193                 { "quiet", 0, 0, 'q' },
 194                 { "verbose", 0, 0, 'v' },
 195                 { "version", 0, 0, 'V' },
 196                 { "kernel", 0, 0, 'k' },
 197 #ifdef HAVE_LIBLTTNG_UST_CTL
 198                 { "ust", 0, 0, 'u' },
 199 #endif
 200                 { NULL, 0, 0, 0 }
 201         };
 202
 203         while (1) {
 204                 int option_index = 0;
 205                 c = getopt_long(argc, argv, "dhqvVku" "c:e:g:",
 206                                 long_options, &option_index);
 207                 if (c == -1) {
 208                         break;
 209                 }
 210
 211                 switch (c) {
 212                 case 0:
 213                         fprintf(stderr, "option %s",
 214                                 long_options[option_index].name);
 215                         if (optarg) {
 216                                 fprintf(stderr, " with arg %s\n", optarg);
 217                                 ret = -1;
 218                                 goto end;
 219                         }
 220                         break;
 221                 case 'c':
 222                         if (lttng_is_setuid_setgid()) {
 223                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 224                                         "-c, --consumerd-cmd-sock");
 225                         } else {
 226                                 snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 227                         }
 228                         break;
 229                 case 'e':
 230                         if (lttng_is_setuid_setgid()) {
 231                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 232                                         "-e, --consumerd-err-sock");
 233                         } else {
 234                                 snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 235                         }
 236                         break;
 237                 case 'd':
 238                         opt_daemon = 1;
 239                         break;
 240                 case 'g':
 241                         if (lttng_is_setuid_setgid()) {
 242                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 243                                         "-g, --group");
 244                         } else {
 245                                 tracing_group_name = optarg;
 246                         }
 247                         break;
 248                 case 'h':
 249                         usage(stdout);
 250                         exit(EXIT_SUCCESS);
 251                 case 'q':
 252                         lttng_opt_quiet = 1;
 253                         break;
 254                 case 'v':
 255                         lttng_opt_verbose = 1;
 256                         break;
 257                 case 'V':
 258                         fprintf(stdout, "%s\n", VERSION);
 259                         exit(EXIT_SUCCESS);
 260                 case 'k':
 261                         opt_type = LTTNG_CONSUMER_KERNEL;
 262                         break;
 263 #ifdef HAVE_LIBLTTNG_UST_CTL
 264                 case 'u':
 265 # if (CAA_BITS_PER_LONG == 64)
 266                         opt_type = LTTNG_CONSUMER64_UST;
 267 # elif (CAA_BITS_PER_LONG == 32)
 268                         opt_type = LTTNG_CONSUMER32_UST;
 269 # else
 270 #  error "Unknown bitness"
 271 # endif
 272                         break;
 273 #endif
 274                 default:
 275                         usage(stderr);
 276                         ret = -1;
 277                         goto end;
 278                 }
 279         }
 280 end:
 281         return ret;
 282 }
 283
 284 /*
 285  * Set open files limit to unlimited. This daemon can open a large number of
 286  * file descriptors in order to consumer multiple kernel traces.
 287  */
 288 static void set_ulimit(void)
 289 {
 290         int ret;
 291         struct rlimit lim;
 292
 293         /* The kernel does not allowed an infinite limit for open files */
 294         lim.rlim_cur = 65535;
 295         lim.rlim_max = 65535;
 296
 297         ret = setrlimit(RLIMIT_NOFILE, &lim);
 298         if (ret < 0) {
 299                 PERROR("failed to set open files limit");
 300         }
 301 }
 302
 303 /*
 304  * main
 305  */
 306 int main(int argc, char **argv)
 307 {
 308         int ret = 0, retval = 0;
 309         void *status;
 310         struct lttng_consumer_local_data *tmp_ctx;
 311
 312         rcu_register_thread();
 313
 314         if (set_signal_handler()) {
 315                 retval = -1;
 316                 goto exit_set_signal_handler;
 317         }
 318
 319         /* Parse arguments */
 320         progname = argv[0];
 321         if (parse_args(argc, argv)) {
 322                 retval = -1;
 323                 goto exit_options;
 324         }
 325
 326         /* Daemonize */
 327         if (opt_daemon) {
 328                 int i;
 329
 330                 /*
 331                  * fork
 332                  * child: setsid, close FD 0, 1, 2, chdir /
 333                  * parent: exit (if fork is successful)
 334                  */
 335                 ret = daemon(0, 0);
 336                 if (ret < 0) {
 337                         PERROR("daemon");
 338                         retval = -1;
 339                         goto exit_options;
 340                 }
 341                 /*
 342                  * We are in the child. Make sure all other file
 343                  * descriptors are closed, in case we are called with
 344                  * more opened file descriptors than the standard ones.
 345                  */
 346                 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
 347                         (void) close(i);
 348                 }
 349         }
 350
 351         /*
 352          * Starting from here, we can create threads. This needs to be after
 353          * lttng_daemonize due to RCU.
 354          */
 355
 356         health_consumerd = health_app_create(NR_HEALTH_CONSUMERD_TYPES);
 357         if (!health_consumerd) {
 358                 retval = -1;
 359                 goto exit_health_consumerd_cleanup;
 360         }
 361
 362         /* Set up max poll set size */
 363         if (lttng_poll_set_max_size()) {
 364                 retval = -1;
 365                 goto exit_init_data;
 366         }
 367
 368         if (*command_sock_path == '\0') {
 369                 switch (opt_type) {
 370                 case LTTNG_CONSUMER_KERNEL:
 371                         ret = snprintf(command_sock_path, PATH_MAX,
 372                                         DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
 373                                         DEFAULT_LTTNG_RUNDIR);
 374                         if (ret < 0) {
 375                                 retval = -1;
 376                                 goto exit_init_data;
 377                         }
 378                         break;
 379                 case LTTNG_CONSUMER64_UST:
 380                         ret = snprintf(command_sock_path, PATH_MAX,
 381                                         DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
 382                                         DEFAULT_LTTNG_RUNDIR);
 383                         if (ret < 0) {
 384                                 retval = -1;
 385                                 goto exit_init_data;
 386                         }
 387                         break;
 388                 case LTTNG_CONSUMER32_UST:
 389                         ret = snprintf(command_sock_path, PATH_MAX,
 390                                         DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
 391                                         DEFAULT_LTTNG_RUNDIR);
 392                         if (ret < 0) {
 393                                 retval = -1;
 394                                 goto exit_init_data;
 395                         }
 396                         break;
 397                 default:
 398                         ERR("Unknown consumerd type");
 399                         retval = -1;
 400                         goto exit_init_data;
 401                 }
 402         }
 403
 404         /* Init */
 405         if (lttng_consumer_init()) {
 406                 retval = -1;
 407                 goto exit_init_data;
 408         }
 409
 410         /* Initialize communication library */
 411         lttcomm_init();
 412         /* Initialize TCP timeout values */
 413         lttcomm_inet_init();
 414
 415         if (!getuid()) {
 416                 /* Set limit for open files */
 417                 set_ulimit();
 418         }
 419
 420         if (run_as_create_worker(argv[0]) < 0) {
 421                 goto exit_init_data;
 422         }
 423
 424         /* create the consumer instance with and assign the callbacks */
 425         ctx = lttng_consumer_create(opt_type, lttng_consumer_read_subbuffer,
 426                 NULL, lttng_consumer_on_recv_stream, NULL);
 427         if (!ctx) {
 428                 retval = -1;
 429                 goto exit_init_data;
 430         }
 431
 432         lttng_consumer_set_command_sock_path(ctx, command_sock_path);
 433         if (*error_sock_path == '\0') {
 434                 switch (opt_type) {
 435                 case LTTNG_CONSUMER_KERNEL:
 436                         ret = snprintf(error_sock_path, PATH_MAX,
 437                                         DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
 438                                         DEFAULT_LTTNG_RUNDIR);
 439                         if (ret < 0) {
 440                                 retval = -1;
 441                                 goto exit_init_data;
 442                         }
 443                         break;
 444                 case LTTNG_CONSUMER64_UST:
 445                         ret = snprintf(error_sock_path, PATH_MAX,
 446                                         DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH,
 447                                         DEFAULT_LTTNG_RUNDIR);
 448                         if (ret < 0) {
 449                                 retval = -1;
 450                                 goto exit_init_data;
 451                         }
 452                         break;
 453                 case LTTNG_CONSUMER32_UST:
 454                         ret = snprintf(error_sock_path, PATH_MAX,
 455                                         DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH,
 456                                         DEFAULT_LTTNG_RUNDIR);
 457                         if (ret < 0) {
 458                                 retval = -1;
 459                                 goto exit_init_data;
 460                         }
 461                         break;
 462                 default:
 463                         ERR("Unknown consumerd type");
 464                         retval = -1;
 465                         goto exit_init_data;
 466                 }
 467         }
 468
 469         /* Connect to the socket created by lttng-sessiond to report errors */
 470         DBG("Connecting to error socket %s", error_sock_path);
 471         ret = lttcomm_connect_unix_sock(error_sock_path);
 472         /*
 473          * Not a fatal error, but all communication with lttng-sessiond will
 474          * fail.
 475          */
 476         if (ret < 0) {
 477                 WARN("Cannot connect to error socket (is lttng-sessiond started?)");
 478         }
 479         lttng_consumer_set_error_sock(ctx, ret);
 480
 481         /*
 482          * Block RT signals used for UST periodical metadata flush and the live
 483          * timer in main, and create a dedicated thread to handle these signals.
 484          */
 485         if (consumer_signal_init()) {
 486                 retval = -1;
 487                 goto exit_init_data;
 488         }
 489
 490         ctx->type = opt_type;
 491
 492         if (utils_create_pipe(health_quit_pipe)) {
 493                 retval = -1;
 494                 goto exit_health_pipe;
 495         }
 496
 497         /* Create thread to manage the client socket */
 498         ret = pthread_create(&health_thread, NULL,
 499                         thread_manage_health, (void *) NULL);
 500         if (ret) {
 501                 errno = ret;
 502                 PERROR("pthread_create health");
 503                 retval = -1;
 504                 goto exit_health_thread;
 505         }
 506
 507         /*
 508          * Wait for health thread to be initialized before letting the
 509          * sessiond thread reply to the sessiond that we are ready.
 510          */
 511         while (uatomic_read(&lttng_consumer_ready)) {
 512                 usleep(100000);
 513         }
 514         cmm_smp_mb();   /* Read ready before following operations */
 515
 516         /*
 517          * Create the thread to manage the UST metadata periodic timer and
 518          * live timer.
 519          */
 520         ret = pthread_create(&metadata_timer_thread, NULL,
 521                         consumer_timer_thread, (void *) ctx);
 522         if (ret) {
 523                 errno = ret;
 524                 PERROR("pthread_create");
 525                 retval = -1;
 526                 goto exit_metadata_timer_thread;
 527         }
 528         metadata_timer_thread_online = true;
 529
 530         /* Create thread to manage channels */
 531         ret = pthread_create(&channel_thread, NULL,
 532                         consumer_thread_channel_poll,
 533                         (void *) ctx);
 534         if (ret) {
 535                 errno = ret;
 536                 PERROR("pthread_create");
 537                 retval = -1;
 538                 goto exit_channel_thread;
 539         }
 540
 541         /* Create thread to manage the polling/writing of trace metadata */
 542         ret = pthread_create(&metadata_thread, NULL,
 543                         consumer_thread_metadata_poll,
 544                         (void *) ctx);
 545         if (ret) {
 546                 errno = ret;
 547                 PERROR("pthread_create");
 548                 retval = -1;
 549                 goto exit_metadata_thread;
 550         }
 551
 552         /* Create thread to manage the polling/writing of trace data */
 553         ret = pthread_create(&data_thread, NULL, consumer_thread_data_poll,
 554                         (void *) ctx);
 555         if (ret) {
 556                 errno = ret;
 557                 PERROR("pthread_create");
 558                 retval = -1;
 559                 goto exit_data_thread;
 560         }
 561
 562         /* Create the thread to manage the receive of fd */
 563         ret = pthread_create(&sessiond_thread, NULL,
 564                         consumer_thread_sessiond_poll,
 565                         (void *) ctx);
 566         if (ret) {
 567                 errno = ret;
 568                 PERROR("pthread_create");
 569                 retval = -1;
 570                 goto exit_sessiond_thread;
 571         }
 572
 573         /*
 574          * This is where we start awaiting program completion (e.g. through
 575          * signal that asks threads to teardown.
 576          */
 577
 578         ret = pthread_join(sessiond_thread, &status);
 579         if (ret) {
 580                 errno = ret;
 581                 PERROR("pthread_join sessiond_thread");
 582                 retval = -1;
 583         }
 584 exit_sessiond_thread:
 585
 586         ret = pthread_join(data_thread, &status);
 587         if (ret) {
 588                 errno = ret;
 589                 PERROR("pthread_join data_thread");
 590                 retval = -1;
 591         }
 592 exit_data_thread:
 593
 594         ret = pthread_join(metadata_thread, &status);
 595         if (ret) {
 596                 errno = ret;
 597                 PERROR("pthread_join metadata_thread");
 598                 retval = -1;
 599         }
 600 exit_metadata_thread:
 601
 602         ret = pthread_join(channel_thread, &status);
 603         if (ret) {
 604                 errno = ret;
 605                 PERROR("pthread_join channel_thread");
 606                 retval = -1;
 607         }
 608 exit_channel_thread:
 609
 610 exit_metadata_timer_thread:
 611
 612         ret = pthread_join(health_thread, &status);
 613         if (ret) {
 614                 errno = ret;
 615                 PERROR("pthread_join health_thread");
 616                 retval = -1;
 617         }
 618 exit_health_thread:
 619
 620         utils_close_pipe(health_quit_pipe);
 621 exit_health_pipe:
 622
 623 exit_init_data:
 624         /*
 625          * Wait for all pending call_rcu work to complete before tearing
 626          * down data structures. call_rcu worker may be trying to
 627          * perform lookups in those structures.
 628          */
 629         rcu_barrier();
 630         lttng_consumer_cleanup();
 631         /*
 632          * Tearing down the metadata timer thread in a
 633          * non-fully-symmetric fashion compared to its creation in case
 634          * lttng_consumer_cleanup() ends up tearing down timers (which
 635          * requires the timer thread to be alive).
 636          */
 637         if (metadata_timer_thread_online) {
 638                 /*
 639                  * Ensure the metadata timer thread exits only after all other
 640                  * threads are gone, because it is required to perform timer
 641                  * teardown synchronization.
 642                  */
 643                 kill(getpid(), LTTNG_CONSUMER_SIG_EXIT);
 644                 ret = pthread_join(metadata_timer_thread, &status);
 645                 if (ret) {
 646                         errno = ret;
 647                         PERROR("pthread_join metadata_timer_thread");
 648                         retval = -1;
 649                 }
 650                 metadata_timer_thread_online = false;
 651         }
 652         tmp_ctx = ctx;
 653         ctx = NULL;
 654         cmm_barrier();  /* Clear ctx for signal handler. */
 655         lttng_consumer_destroy(tmp_ctx);
 656
 657         if (health_consumerd) {
 658                 health_app_destroy(health_consumerd);
 659         }
 660         /* Ensure all prior call_rcu are done. */
 661         rcu_barrier();
 662
 663         run_as_destroy_worker();
 664
 665 exit_health_consumerd_cleanup:
 666 exit_options:
 667 exit_set_signal_handler:
 668
 669         rcu_unregister_thread();
 670
 671         if (!retval) {
 672                 exit(EXIT_SUCCESS);
 673         } else {
 674                 exit(EXIT_FAILURE);
 675         }
 676 }