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

   1 /*
   2  * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
   3  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #define _LGPL_SOURCE
  10 #include <fcntl.h>
  11 #include <getopt.h>
  12 #include <grp.h>
  13 #include <limits.h>
  14 #include <pthread.h>
  15 #include <signal.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <sys/ipc.h>
  20 #include <sys/resource.h>
  21 #include <sys/shm.h>
  22 #include <sys/socket.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <urcu/list.h>
  26 #include <poll.h>
  27 #include <unistd.h>
  28 #include <sys/mman.h>
  29 #include <assert.h>
  30 #include <urcu/compiler.h>
  31 #include <ulimit.h>
  32
  33 #include <common/defaults.h>
  34 #include <common/common.h>
  35 #include <common/consumer/consumer.h>
  36 #include <common/consumer/consumer-timer.h>
  37 #include <common/compat/poll.h>
  38 #include <common/compat/getenv.h>
  39 #include <common/sessiond-comm/sessiond-comm.h>
  40 #include <common/utils.h>
  41
  42 #include "lttng-consumerd.h"
  43 #include "health-consumerd.h"
  44
  45 /* threads (channel handling, poll, metadata, sessiond) */
  46
  47 static pthread_t channel_thread, data_thread, metadata_thread,
  48                 sessiond_thread, metadata_timer_thread, health_thread;
  49 static bool metadata_timer_thread_online;
  50
  51 /* to count the number of times the user pressed ctrl+c */
  52 static int sigintcount = 0;
  53
  54 /* Argument variables */
  55 int lttng_opt_quiet;    /* not static in error.h */
  56 int lttng_opt_verbose;  /* not static in error.h */
  57 int lttng_opt_mi;       /* not static in error.h */
  58
  59 static int opt_daemon;
  60 static const char *progname;
  61 static char command_sock_path[PATH_MAX]; /* Global command socket path */
  62 static char error_sock_path[PATH_MAX]; /* Global error path */
  63 static enum lttng_consumer_type opt_type = LTTNG_CONSUMER_KERNEL;
  64
  65 /* the liblttngconsumerd context */
  66 static struct lttng_consumer_local_data *ctx;
  67
  68 /* Consumerd health monitoring */
  69 struct health_app *health_consumerd;
  70
  71 const char *tracing_group_name = DEFAULT_TRACING_GROUP;
  72
  73 int lttng_consumer_ready = NR_LTTNG_CONSUMER_READY;
  74
  75 enum lttng_consumer_type lttng_consumer_get_type(void)
  76 {
  77         if (!ctx) {
  78                 return LTTNG_CONSUMER_UNKNOWN;
  79         }
  80         return ctx->type;
  81 }
  82
  83 /*
  84  * Signal handler for the daemon
  85  */
  86 static void sighandler(int sig, siginfo_t *siginfo, void *arg)
  87 {
  88         if (sig == SIGINT && sigintcount++ == 0) {
  89                 DBG("ignoring first SIGINT");
  90                 return;
  91         }
  92
  93         if (sig == SIGBUS) {
  94                 int write_ret;
  95                 const char msg[] = "Received SIGBUS, aborting program.\n";
  96
  97                 lttng_consumer_sigbus_handle(siginfo->si_addr);
  98                 /*
  99                  * If ustctl did not catch this signal (triggering a
 100                  * siglongjmp), abort the program. Otherwise, the execution
 101                  * will resume from the ust-ctl call which caused this error.
 102                  *
 103                  * The return value is ignored since the program aborts anyhow.
 104                  */
 105                 write_ret = write(STDERR_FILENO, msg, sizeof(msg));
 106                 (void) write_ret;
 107                 abort();
 108         }
 109
 110         if (ctx) {
 111                 lttng_consumer_should_exit(ctx);
 112         }
 113 }
 114
 115 /*
 116  * Setup signal handler for :
 117  *      SIGINT, SIGTERM, SIGPIPE, SIGBUS
 118  */
 119 static int set_signal_handler(void)
 120 {
 121         int ret = 0;
 122         struct sigaction sa;
 123         sigset_t sigset;
 124
 125         if ((ret = sigemptyset(&sigset)) < 0) {
 126                 PERROR("sigemptyset");
 127                 return ret;
 128         }
 129
 130         sa.sa_mask = sigset;
 131         sa.sa_flags = SA_SIGINFO;
 132
 133         sa.sa_sigaction = sighandler;
 134         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 135                 PERROR("sigaction");
 136                 return ret;
 137         }
 138
 139         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 140                 PERROR("sigaction");
 141                 return ret;
 142         }
 143
 144         if ((ret = sigaction(SIGBUS, &sa, NULL)) < 0) {
 145                 PERROR("sigaction");
 146                 return ret;
 147         }
 148
 149         sa.sa_flags = 0;
 150         sa.sa_handler = SIG_IGN;
 151         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 152                 PERROR("sigaction");
 153                 return ret;
 154         }
 155
 156         return ret;
 157 }
 158
 159 /*
 160  * Usage function on stream file.
 161  */
 162 static void usage(FILE *fp)
 163 {
 164         fprintf(fp, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 165         fprintf(fp, "  -h, --help                         "
 166                         "Display this usage.\n");
 167         fprintf(fp, "  -c, --consumerd-cmd-sock PATH      "
 168                         "Specify path for the command socket\n");
 169         fprintf(fp, "  -e, --consumerd-err-sock PATH      "
 170                         "Specify path for the error socket\n");
 171         fprintf(fp, "  -d, --daemonize                    "
 172                         "Start as a daemon.\n");
 173         fprintf(fp, "  -q, --quiet                        "
 174                         "No output at all.\n");
 175         fprintf(fp, "  -v, --verbose                      "
 176                         "Verbose mode. Activate DBG() macro.\n");
 177         fprintf(fp, "  -V, --version                      "
 178                         "Show version number.\n");
 179         fprintf(fp, "  -g, --group NAME                   "
 180                         "Specify the tracing group name. (default: tracing)\n");
 181         fprintf(fp, "  -k, --kernel                       "
 182                         "Consumer kernel buffers (default).\n");
 183         fprintf(fp, "  -u, --ust                          "
 184                         "Consumer UST buffers.%s\n",
 185 #ifdef HAVE_LIBLTTNG_UST_CTL
 186                         ""
 187 #else
 188                         " (support not compiled in)"
 189 #endif
 190                         );
 191 }
 192
 193 /*
 194  * daemon argument parsing
 195  */
 196 static int parse_args(int argc, char **argv)
 197 {
 198         int c, ret = 0;
 199
 200         static struct option long_options[] = {
 201                 { "consumerd-cmd-sock", 1, 0, 'c' },
 202                 { "consumerd-err-sock", 1, 0, 'e' },
 203                 { "daemonize", 0, 0, 'd' },
 204                 { "group", 1, 0, 'g' },
 205                 { "help", 0, 0, 'h' },
 206                 { "quiet", 0, 0, 'q' },
 207                 { "verbose", 0, 0, 'v' },
 208                 { "version", 0, 0, 'V' },
 209                 { "kernel", 0, 0, 'k' },
 210 #ifdef HAVE_LIBLTTNG_UST_CTL
 211                 { "ust", 0, 0, 'u' },
 212 #endif
 213                 { NULL, 0, 0, 0 }
 214         };
 215
 216         while (1) {
 217                 int option_index = 0;
 218                 c = getopt_long(argc, argv, "dhqvVku" "c:e:g:",
 219                                 long_options, &option_index);
 220                 if (c == -1) {
 221                         break;
 222                 }
 223
 224                 switch (c) {
 225                 case 0:
 226                         fprintf(stderr, "option %s",
 227                                 long_options[option_index].name);
 228                         if (optarg) {
 229                                 fprintf(stderr, " with arg %s\n", optarg);
 230                                 ret = -1;
 231                                 goto end;
 232                         }
 233                         break;
 234                 case 'c':
 235                         if (lttng_is_setuid_setgid()) {
 236                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 237                                         "-c, --consumerd-cmd-sock");
 238                         } else {
 239                                 snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 240                         }
 241                         break;
 242                 case 'e':
 243                         if (lttng_is_setuid_setgid()) {
 244                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 245                                         "-e, --consumerd-err-sock");
 246                         } else {
 247                                 snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 248                         }
 249                         break;
 250                 case 'd':
 251                         opt_daemon = 1;
 252                         break;
 253                 case 'g':
 254                         if (lttng_is_setuid_setgid()) {
 255                                 WARN("Getting '%s' argument from setuid/setgid binary refused for security reasons.",
 256                                         "-g, --group");
 257                         } else {
 258                                 tracing_group_name = optarg;
 259                         }
 260                         break;
 261                 case 'h':
 262                         usage(stdout);
 263                         exit(EXIT_SUCCESS);
 264                 case 'q':
 265                         lttng_opt_quiet = 1;
 266                         break;
 267                 case 'v':
 268                         lttng_opt_verbose = 3;
 269                         break;
 270                 case 'V':
 271                         fprintf(stdout, "%s\n", VERSION);
 272                         exit(EXIT_SUCCESS);
 273                 case 'k':
 274                         opt_type = LTTNG_CONSUMER_KERNEL;
 275                         break;
 276 #ifdef HAVE_LIBLTTNG_UST_CTL
 277                 case 'u':
 278 # if (CAA_BITS_PER_LONG == 64)
 279                         opt_type = LTTNG_CONSUMER64_UST;
 280 # elif (CAA_BITS_PER_LONG == 32)
 281                         opt_type = LTTNG_CONSUMER32_UST;
 282 # else
 283 #  error "Unknown bitness"
 284 # endif
 285                         break;
 286 #endif
 287                 default:
 288                         usage(stderr);
 289                         ret = -1;
 290                         goto end;
 291                 }
 292         }
 293 end:
 294         return ret;
 295 }
 296
 297 /*
 298  * Set open files limit to unlimited. This daemon can open a large number of
 299  * file descriptors in order to consumer multiple kernel traces.
 300  */
 301 static void set_ulimit(void)
 302 {
 303         int ret;
 304         struct rlimit lim;
 305
 306         /* The kernel does not allowed an infinite limit for open files */
 307         lim.rlim_cur = 65535;
 308         lim.rlim_max = 65535;
 309
 310         ret = setrlimit(RLIMIT_NOFILE, &lim);
 311         if (ret < 0) {
 312                 PERROR("failed to set open files limit");
 313         }
 314 }
 315
 316 /*
 317  * main
 318  */
 319 int main(int argc, char **argv)
 320 {
 321         int ret = 0, retval = 0;
 322         void *status;
 323         struct lttng_consumer_local_data *tmp_ctx;
 324
 325         rcu_register_thread();
 326
 327         if (run_as_create_worker(argv[0], NULL, NULL) < 0) {
 328                 goto exit_set_signal_handler;
 329         }
 330
 331         if (set_signal_handler()) {
 332                 retval = -1;
 333                 goto exit_set_signal_handler;
 334         }
 335
 336         /* Parse arguments */
 337         progname = argv[0];
 338         if (parse_args(argc, argv)) {
 339                 retval = -1;
 340                 goto exit_options;
 341         }
 342
 343         /* Daemonize */
 344         if (opt_daemon) {
 345                 int i;
 346
 347                 /*
 348                  * fork
 349                  * child: setsid, close FD 0, 1, 2, chdir /
 350                  * parent: exit (if fork is successful)
 351                  */
 352                 ret = daemon(0, 0);
 353                 if (ret < 0) {
 354                         PERROR("daemon");
 355                         retval = -1;
 356                         goto exit_options;
 357                 }
 358                 /*
 359                  * We are in the child. Make sure all other file
 360                  * descriptors are closed, in case we are called with
 361                  * more opened file descriptors than the standard ones.
 362                  */
 363                 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
 364                         (void) close(i);
 365                 }
 366         }
 367
 368         /*
 369          * Starting from here, we can create threads. This needs to be after
 370          * lttng_daemonize due to RCU.
 371          */
 372
 373         health_consumerd = health_app_create(NR_HEALTH_CONSUMERD_TYPES);
 374         if (!health_consumerd) {
 375                 retval = -1;
 376                 goto exit_health_consumerd_cleanup;
 377         }
 378
 379         if (*command_sock_path == '\0') {
 380                 switch (opt_type) {
 381                 case LTTNG_CONSUMER_KERNEL:
 382                         ret = snprintf(command_sock_path, PATH_MAX,
 383                                         DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
 384                                         DEFAULT_LTTNG_RUNDIR);
 385                         if (ret < 0) {
 386                                 retval = -1;
 387                                 goto exit_init_data;
 388                         }
 389                         break;
 390                 case LTTNG_CONSUMER64_UST:
 391                         ret = snprintf(command_sock_path, PATH_MAX,
 392                                         DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH,
 393                                         DEFAULT_LTTNG_RUNDIR);
 394                         if (ret < 0) {
 395                                 retval = -1;
 396                                 goto exit_init_data;
 397                         }
 398                         break;
 399                 case LTTNG_CONSUMER32_UST:
 400                         ret = snprintf(command_sock_path, PATH_MAX,
 401                                         DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH,
 402                                         DEFAULT_LTTNG_RUNDIR);
 403                         if (ret < 0) {
 404                                 retval = -1;
 405                                 goto exit_init_data;
 406                         }
 407                         break;
 408                 default:
 409                         ERR("Unknown consumerd type");
 410                         retval = -1;
 411                         goto exit_init_data;
 412                 }
 413         }
 414
 415         /* Init */
 416         if (lttng_consumer_init()) {
 417                 retval = -1;
 418                 goto exit_init_data;
 419         }
 420
 421         /* Initialize communication library */
 422         lttcomm_init();
 423         /* Initialize TCP timeout values */
 424         lttcomm_inet_init();
 425
 426         if (!getuid()) {
 427                 /* Set limit for open files */
 428                 set_ulimit();
 429         }
 430
 431         /* create the consumer instance with and assign the callbacks */
 432         ctx = lttng_consumer_create(opt_type, lttng_consumer_read_subbuffer,
 433                 NULL, lttng_consumer_on_recv_stream, NULL);
 434         if (!ctx) {
 435                 retval = -1;
 436                 goto exit_init_data;
 437         }
 438
 439         lttng_consumer_set_command_sock_path(ctx, command_sock_path);
 440         if (*error_sock_path == '\0') {
 441                 switch (opt_type) {
 442                 case LTTNG_CONSUMER_KERNEL:
 443                         ret = snprintf(error_sock_path, PATH_MAX,
 444                                         DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
 445                                         DEFAULT_LTTNG_RUNDIR);
 446                         if (ret < 0) {
 447                                 retval = -1;
 448                                 goto exit_init_data;
 449                         }
 450                         break;
 451                 case LTTNG_CONSUMER64_UST:
 452                         ret = snprintf(error_sock_path, PATH_MAX,
 453                                         DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH,
 454                                         DEFAULT_LTTNG_RUNDIR);
 455                         if (ret < 0) {
 456                                 retval = -1;
 457                                 goto exit_init_data;
 458                         }
 459                         break;
 460                 case LTTNG_CONSUMER32_UST:
 461                         ret = snprintf(error_sock_path, PATH_MAX,
 462                                         DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH,
 463                                         DEFAULT_LTTNG_RUNDIR);
 464                         if (ret < 0) {
 465                                 retval = -1;
 466                                 goto exit_init_data;
 467                         }
 468                         break;
 469                 default:
 470                         ERR("Unknown consumerd type");
 471                         retval = -1;
 472                         goto exit_init_data;
 473                 }
 474         }
 475
 476         /* Connect to the socket created by lttng-sessiond to report errors */
 477         DBG("Connecting to error socket %s", error_sock_path);
 478         ret = lttcomm_connect_unix_sock(error_sock_path);
 479         /*
 480          * Not a fatal error, but all communication with lttng-sessiond will
 481          * fail.
 482          */
 483         if (ret < 0) {
 484                 WARN("Cannot connect to error socket (is lttng-sessiond started?)");
 485         }
 486         lttng_consumer_set_error_sock(ctx, ret);
 487
 488         /*
 489          * Block RT signals used for UST periodical metadata flush and the live
 490          * timer in main, and create a dedicated thread to handle these signals.
 491          */
 492         if (consumer_signal_init()) {
 493                 retval = -1;
 494                 goto exit_init_data;
 495         }
 496
 497         ctx->type = opt_type;
 498
 499         if (utils_create_pipe(health_quit_pipe)) {
 500                 retval = -1;
 501                 goto exit_health_pipe;
 502         }
 503
 504         /* Create thread to manage the client socket */
 505         ret = pthread_create(&health_thread, default_pthread_attr(),
 506                         thread_manage_health, (void *) NULL);
 507         if (ret) {
 508                 errno = ret;
 509                 PERROR("pthread_create health");
 510                 retval = -1;
 511                 goto exit_health_thread;
 512         }
 513
 514         /*
 515          * Wait for health thread to be initialized before letting the
 516          * sessiond thread reply to the sessiond that we are ready.
 517          */
 518         while (uatomic_read(&lttng_consumer_ready)) {
 519                 usleep(100000);
 520         }
 521         cmm_smp_mb();   /* Read ready before following operations */
 522
 523         /*
 524          * Create the thread to manage the UST metadata periodic timer and
 525          * live timer.
 526          */
 527         ret = pthread_create(&metadata_timer_thread, NULL,
 528                         consumer_timer_thread, (void *) ctx);
 529         if (ret) {
 530                 errno = ret;
 531                 PERROR("pthread_create");
 532                 retval = -1;
 533                 goto exit_metadata_timer_thread;
 534         }
 535         metadata_timer_thread_online = true;
 536
 537         /* Create thread to manage channels */
 538         ret = pthread_create(&channel_thread, default_pthread_attr(),
 539                         consumer_thread_channel_poll,
 540                         (void *) ctx);
 541         if (ret) {
 542                 errno = ret;
 543                 PERROR("pthread_create");
 544                 retval = -1;
 545                 goto exit_channel_thread;
 546         }
 547
 548         /* Create thread to manage the polling/writing of trace metadata */
 549         ret = pthread_create(&metadata_thread, default_pthread_attr(),
 550                         consumer_thread_metadata_poll,
 551                         (void *) ctx);
 552         if (ret) {
 553                 errno = ret;
 554                 PERROR("pthread_create");
 555                 retval = -1;
 556                 goto exit_metadata_thread;
 557         }
 558
 559         /* Create thread to manage the polling/writing of trace data */
 560         ret = pthread_create(&data_thread, default_pthread_attr(),
 561                         consumer_thread_data_poll, (void *) ctx);
 562         if (ret) {
 563                 errno = ret;
 564                 PERROR("pthread_create");
 565                 retval = -1;
 566                 goto exit_data_thread;
 567         }
 568
 569         /* Create the thread to manage the reception of fds */
 570         ret = pthread_create(&sessiond_thread, default_pthread_attr(),
 571                         consumer_thread_sessiond_poll,
 572                         (void *) ctx);
 573         if (ret) {
 574                 errno = ret;
 575                 PERROR("pthread_create");
 576                 retval = -1;
 577                 goto exit_sessiond_thread;
 578         }
 579
 580
 581         /*
 582          * This is where we start awaiting program completion (e.g. through
 583          * signal that asks threads to teardown.
 584          */
 585
 586         ret = pthread_join(sessiond_thread, &status);
 587         if (ret) {
 588                 errno = ret;
 589                 PERROR("pthread_join sessiond_thread");
 590                 retval = -1;
 591         }
 592 exit_sessiond_thread:
 593
 594         ret = pthread_join(data_thread, &status);
 595         if (ret) {
 596                 errno = ret;
 597                 PERROR("pthread_join data_thread");
 598                 retval = -1;
 599         }
 600 exit_data_thread:
 601
 602         ret = pthread_join(metadata_thread, &status);
 603         if (ret) {
 604                 errno = ret;
 605                 PERROR("pthread_join metadata_thread");
 606                 retval = -1;
 607         }
 608 exit_metadata_thread:
 609
 610         ret = pthread_join(channel_thread, &status);
 611         if (ret) {
 612                 errno = ret;
 613                 PERROR("pthread_join channel_thread");
 614                 retval = -1;
 615         }
 616 exit_channel_thread:
 617
 618 exit_metadata_timer_thread:
 619
 620         ret = pthread_join(health_thread, &status);
 621         if (ret) {
 622                 errno = ret;
 623                 PERROR("pthread_join health_thread");
 624                 retval = -1;
 625         }
 626 exit_health_thread:
 627
 628         utils_close_pipe(health_quit_pipe);
 629 exit_health_pipe:
 630
 631 exit_init_data:
 632         /*
 633          * Wait for all pending call_rcu work to complete before tearing
 634          * down data structures. call_rcu worker may be trying to
 635          * perform lookups in those structures.
 636          */
 637         rcu_barrier();
 638         lttng_consumer_cleanup();
 639         /*
 640          * Tearing down the metadata timer thread in a
 641          * non-fully-symmetric fashion compared to its creation in case
 642          * lttng_consumer_cleanup() ends up tearing down timers (which
 643          * requires the timer thread to be alive).
 644          */
 645         if (metadata_timer_thread_online) {
 646                 /*
 647                  * Ensure the metadata timer thread exits only after all other
 648                  * threads are gone, because it is required to perform timer
 649                  * teardown synchronization.
 650                  */
 651                 kill(getpid(), LTTNG_CONSUMER_SIG_EXIT);
 652                 ret = pthread_join(metadata_timer_thread, &status);
 653                 if (ret) {
 654                         errno = ret;
 655                         PERROR("pthread_join metadata_timer_thread");
 656                         retval = -1;
 657                 }
 658                 ret = consumer_timer_thread_get_channel_monitor_pipe();
 659                 if (ret >= 0) {
 660                         ret = close(ret);
 661                         if (ret) {
 662                                 PERROR("close channel monitor pipe");
 663                         }
 664                 }
 665                 metadata_timer_thread_online = false;
 666         }
 667         tmp_ctx = ctx;
 668         ctx = NULL;
 669         cmm_barrier();  /* Clear ctx for signal handler. */
 670         lttng_consumer_destroy(tmp_ctx);
 671
 672         if (health_consumerd) {
 673                 health_app_destroy(health_consumerd);
 674         }
 675         /* Ensure all prior call_rcu are done. */
 676         rcu_barrier();
 677
 678         run_as_destroy_worker();
 679
 680 exit_health_consumerd_cleanup:
 681 exit_options:
 682 exit_set_signal_handler:
 683
 684         rcu_unregister_thread();
 685
 686         if (!retval) {
 687                 exit(EXIT_SUCCESS);
 688         } else {
 689                 exit(EXIT_FAILURE);
 690         }
 691 }