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 = 3;
 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         if (*command_sock_path == '\0') {
 363                 switch (opt_type) {
 364                 case LTTNG_CONSUMER_KERNEL:
 365                         ret = snprintf(command_sock_path, PATH_MAX,
 366                                         DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
 367                                         DEFAULT_LTTNG_RUNDIR);
 368                         if (ret < 0) {
 369                                 retval = -1;
 370                                 goto exit_init_data;
 371                         }
 372                         break;
 373                 case LTTNG_CONSUMER64_UST:
 374                         ret = snprintf(command_sock_path, PATH_MAX,
 375                                         DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
 376                                         DEFAULT_LTTNG_RUNDIR);
 377                         if (ret < 0) {
 378                                 retval = -1;
 379                                 goto exit_init_data;
 380                         }
 381                         break;
 382                 case LTTNG_CONSUMER32_UST:
 383                         ret = snprintf(command_sock_path, PATH_MAX,
 384                                         DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
 385                                         DEFAULT_LTTNG_RUNDIR);
 386                         if (ret < 0) {
 387                                 retval = -1;
 388                                 goto exit_init_data;
 389                         }
 390                         break;
 391                 default:
 392                         ERR("Unknown consumerd type");
 393                         retval = -1;
 394                         goto exit_init_data;
 395                 }
 396         }
 397
 398         /* Init */
 399         if (lttng_consumer_init()) {
 400                 retval = -1;
 401                 goto exit_init_data;
 402         }
 403
 404         /* Initialize communication library */
 405         lttcomm_init();
 406         /* Initialize TCP timeout values */
 407         lttcomm_inet_init();
 408
 409         if (!getuid()) {
 410                 /* Set limit for open files */
 411                 set_ulimit();
 412         }
 413
 414         if (run_as_create_worker(argv[0]) < 0) {
 415                 goto exit_init_data;
 416         }
 417
 418         /* create the consumer instance with and assign the callbacks */
 419         ctx = lttng_consumer_create(opt_type, lttng_consumer_read_subbuffer,
 420                 NULL, lttng_consumer_on_recv_stream, NULL);
 421         if (!ctx) {
 422                 retval = -1;
 423                 goto exit_init_data;
 424         }
 425
 426         lttng_consumer_set_command_sock_path(ctx, command_sock_path);
 427         if (*error_sock_path == '\0') {
 428                 switch (opt_type) {
 429                 case LTTNG_CONSUMER_KERNEL:
 430                         ret = snprintf(error_sock_path, PATH_MAX,
 431                                         DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
 432                                         DEFAULT_LTTNG_RUNDIR);
 433                         if (ret < 0) {
 434                                 retval = -1;
 435                                 goto exit_init_data;
 436                         }
 437                         break;
 438                 case LTTNG_CONSUMER64_UST:
 439                         ret = snprintf(error_sock_path, PATH_MAX,
 440                                         DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH,
 441                                         DEFAULT_LTTNG_RUNDIR);
 442                         if (ret < 0) {
 443                                 retval = -1;
 444                                 goto exit_init_data;
 445                         }
 446                         break;
 447                 case LTTNG_CONSUMER32_UST:
 448                         ret = snprintf(error_sock_path, PATH_MAX,
 449                                         DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH,
 450                                         DEFAULT_LTTNG_RUNDIR);
 451                         if (ret < 0) {
 452                                 retval = -1;
 453                                 goto exit_init_data;
 454                         }
 455                         break;
 456                 default:
 457                         ERR("Unknown consumerd type");
 458                         retval = -1;
 459                         goto exit_init_data;
 460                 }
 461         }
 462
 463         /* Connect to the socket created by lttng-sessiond to report errors */
 464         DBG("Connecting to error socket %s", error_sock_path);
 465         ret = lttcomm_connect_unix_sock(error_sock_path);
 466         /*
 467          * Not a fatal error, but all communication with lttng-sessiond will
 468          * fail.
 469          */
 470         if (ret < 0) {
 471                 WARN("Cannot connect to error socket (is lttng-sessiond started?)");
 472         }
 473         lttng_consumer_set_error_sock(ctx, ret);
 474
 475         /*
 476          * Block RT signals used for UST periodical metadata flush and the live
 477          * timer in main, and create a dedicated thread to handle these signals.
 478          */
 479         if (consumer_signal_init()) {
 480                 retval = -1;
 481                 goto exit_init_data;
 482         }
 483
 484         ctx->type = opt_type;
 485
 486         if (utils_create_pipe(health_quit_pipe)) {
 487                 retval = -1;
 488                 goto exit_health_pipe;
 489         }
 490
 491         /* Create thread to manage the client socket */
 492         ret = pthread_create(&health_thread, default_pthread_attr(),
 493                         thread_manage_health, (void *) NULL);
 494         if (ret) {
 495                 errno = ret;
 496                 PERROR("pthread_create health");
 497                 retval = -1;
 498                 goto exit_health_thread;
 499         }
 500
 501         /*
 502          * Wait for health thread to be initialized before letting the
 503          * sessiond thread reply to the sessiond that we are ready.
 504          */
 505         while (uatomic_read(&lttng_consumer_ready)) {
 506                 usleep(100000);
 507         }
 508         cmm_smp_mb();   /* Read ready before following operations */
 509
 510         /*
 511          * Create the thread to manage the UST metadata periodic timer and
 512          * live timer.
 513          */
 514         ret = pthread_create(&metadata_timer_thread, NULL,
 515                         consumer_timer_thread, (void *) ctx);
 516         if (ret) {
 517                 errno = ret;
 518                 PERROR("pthread_create");
 519                 retval = -1;
 520                 goto exit_metadata_timer_thread;
 521         }
 522         metadata_timer_thread_online = true;
 523
 524         /* Create thread to manage channels */
 525         ret = pthread_create(&channel_thread, default_pthread_attr(),
 526                         consumer_thread_channel_poll,
 527                         (void *) ctx);
 528         if (ret) {
 529                 errno = ret;
 530                 PERROR("pthread_create");
 531                 retval = -1;
 532                 goto exit_channel_thread;
 533         }
 534
 535         /* Create thread to manage the polling/writing of trace metadata */
 536         ret = pthread_create(&metadata_thread, default_pthread_attr(),
 537                         consumer_thread_metadata_poll,
 538                         (void *) ctx);
 539         if (ret) {
 540                 errno = ret;
 541                 PERROR("pthread_create");
 542                 retval = -1;
 543                 goto exit_metadata_thread;
 544         }
 545
 546         /* Create thread to manage the polling/writing of trace data */
 547         ret = pthread_create(&data_thread, default_pthread_attr(),
 548                         consumer_thread_data_poll, (void *) ctx);
 549         if (ret) {
 550                 errno = ret;
 551                 PERROR("pthread_create");
 552                 retval = -1;
 553                 goto exit_data_thread;
 554         }
 555
 556         /* Create the thread to manage the reception of fds */
 557         ret = pthread_create(&sessiond_thread, default_pthread_attr(),
 558                         consumer_thread_sessiond_poll,
 559                         (void *) ctx);
 560         if (ret) {
 561                 errno = ret;
 562                 PERROR("pthread_create");
 563                 retval = -1;
 564                 goto exit_sessiond_thread;
 565         }
 566
 567
 568         /*
 569          * This is where we start awaiting program completion (e.g. through
 570          * signal that asks threads to teardown.
 571          */
 572
 573         ret = pthread_join(sessiond_thread, &status);
 574         if (ret) {
 575                 errno = ret;
 576                 PERROR("pthread_join sessiond_thread");
 577                 retval = -1;
 578         }
 579 exit_sessiond_thread:
 580
 581         ret = pthread_join(data_thread, &status);
 582         if (ret) {
 583                 errno = ret;
 584                 PERROR("pthread_join data_thread");
 585                 retval = -1;
 586         }
 587 exit_data_thread:
 588
 589         ret = pthread_join(metadata_thread, &status);
 590         if (ret) {
 591                 errno = ret;
 592                 PERROR("pthread_join metadata_thread");
 593                 retval = -1;
 594         }
 595 exit_metadata_thread:
 596
 597         ret = pthread_join(channel_thread, &status);
 598         if (ret) {
 599                 errno = ret;
 600                 PERROR("pthread_join channel_thread");
 601                 retval = -1;
 602         }
 603 exit_channel_thread:
 604
 605 exit_metadata_timer_thread:
 606
 607         ret = pthread_join(health_thread, &status);
 608         if (ret) {
 609                 errno = ret;
 610                 PERROR("pthread_join health_thread");
 611                 retval = -1;
 612         }
 613 exit_health_thread:
 614
 615         utils_close_pipe(health_quit_pipe);
 616 exit_health_pipe:
 617
 618 exit_init_data:
 619         /*
 620          * Wait for all pending call_rcu work to complete before tearing
 621          * down data structures. call_rcu worker may be trying to
 622          * perform lookups in those structures.
 623          */
 624         rcu_barrier();
 625         lttng_consumer_cleanup();
 626         /*
 627          * Tearing down the metadata timer thread in a
 628          * non-fully-symmetric fashion compared to its creation in case
 629          * lttng_consumer_cleanup() ends up tearing down timers (which
 630          * requires the timer thread to be alive).
 631          */
 632         if (metadata_timer_thread_online) {
 633                 /*
 634                  * Ensure the metadata timer thread exits only after all other
 635                  * threads are gone, because it is required to perform timer
 636                  * teardown synchronization.
 637                  */
 638                 kill(getpid(), LTTNG_CONSUMER_SIG_EXIT);
 639                 ret = pthread_join(metadata_timer_thread, &status);
 640                 if (ret) {
 641                         errno = ret;
 642                         PERROR("pthread_join metadata_timer_thread");
 643                         retval = -1;
 644                 }
 645                 ret = consumer_timer_thread_get_channel_monitor_pipe();
 646                 if (ret >= 0) {
 647                         ret = close(ret);
 648                         if (ret) {
 649                                 PERROR("close channel monitor pipe");
 650                         }
 651                 }
 652                 metadata_timer_thread_online = false;
 653         }
 654         tmp_ctx = ctx;
 655         ctx = NULL;
 656         cmm_barrier();  /* Clear ctx for signal handler. */
 657         lttng_consumer_destroy(tmp_ctx);
 658
 659         if (health_consumerd) {
 660                 health_app_destroy(health_consumerd);
 661         }
 662         /* Ensure all prior call_rcu are done. */
 663         rcu_barrier();
 664
 665         run_as_destroy_worker();
 666
 667 exit_health_consumerd_cleanup:
 668 exit_options:
 669 exit_set_signal_handler:
 670
 671         rcu_unregister_thread();
 672
 673         if (!retval) {
 674                 exit(EXIT_SUCCESS);
 675         } else {
 676                 exit(EXIT_FAILURE);
 677         }
 678 }