src/bin/lttng-consumerd/lttng-consumerd.cpp

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