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 _GNU_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 <config.h>
  41 #include <urcu/compiler.h>
  42 #include <ulimit.h>
  43
  44 #include <common/defaults.h>
  45 #include <common/common.h>
  46 #include <common/consumer.h>
  47 #include <common/compat/poll.h>
  48 #include <common/sessiond-comm/sessiond-comm.h>
  49
  50 #include "lttng-consumerd.h"
  51
  52 /* TODO : support UST (all direct kernel-ctl accesses). */
  53
  54 /* the two threads (receive fd, poll and metadata) */
  55 static pthread_t data_thread, metadata_thread, sessiond_thread;
  56
  57 /* to count the number of times the user pressed ctrl+c */
  58 static int sigintcount = 0;
  59
  60 /* Argument variables */
  61 int lttng_opt_quiet;    /* not static in error.h */
  62 int lttng_opt_verbose;  /* not static in error.h */
  63 static int opt_daemon;
  64 static const char *progname;
  65 static char command_sock_path[PATH_MAX]; /* Global command socket path */
  66 static char error_sock_path[PATH_MAX]; /* Global error path */
  67 static enum lttng_consumer_type opt_type = LTTNG_CONSUMER_KERNEL;
  68
  69 /* the liblttngconsumerd context */
  70 static struct lttng_consumer_local_data *ctx;
  71
  72 /*
  73  * Signal handler for the daemon
  74  */
  75 static void sighandler(int sig)
  76 {
  77         if (sig == SIGINT && sigintcount++ == 0) {
  78                 DBG("ignoring first SIGINT");
  79                 return;
  80         }
  81
  82         /*
  83          * Ignore SIGPIPE because it should not stop the consumer whenever a
  84          * SIGPIPE is catched through a FD operation.
  85          */
  86         if (sig == SIGPIPE) {
  87                 return;
  88         }
  89
  90         lttng_consumer_should_exit(ctx);
  91 }
  92
  93 /*
  94  * Setup signal handler for :
  95  *      SIGINT, SIGTERM, SIGPIPE
  96  */
  97 static int set_signal_handler(void)
  98 {
  99         int ret = 0;
 100         struct sigaction sa;
 101         sigset_t sigset;
 102
 103         if ((ret = sigemptyset(&sigset)) < 0) {
 104                 perror("sigemptyset");
 105                 return ret;
 106         }
 107
 108         sa.sa_handler = sighandler;
 109         sa.sa_mask = sigset;
 110         sa.sa_flags = 0;
 111         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
 112                 perror("sigaction");
 113                 return ret;
 114         }
 115
 116         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 117                 perror("sigaction");
 118                 return ret;
 119         }
 120
 121         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 122                 perror("sigaction");
 123                 return ret;
 124         }
 125
 126         return ret;
 127 }
 128
 129 /*
 130  * Usage function on stream file.
 131  */
 132 static void usage(FILE *fp)
 133 {
 134         fprintf(fp, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 135         fprintf(fp, "  -h, --help                         "
 136                         "Display this usage.\n");
 137         fprintf(fp, "  -c, --consumerd-cmd-sock PATH     "
 138                         "Specify path for the command socket\n");
 139         fprintf(fp, "  -e, --consumerd-err-sock PATH     "
 140                         "Specify path for the error socket\n");
 141         fprintf(fp, "  -d, --daemonize                    "
 142                         "Start as a daemon.\n");
 143         fprintf(fp, "  -q, --quiet                        "
 144                         "No output at all.\n");
 145         fprintf(fp, "  -v, --verbose                      "
 146                         "Verbose mode. Activate DBG() macro.\n");
 147         fprintf(fp, "  -V, --version                      "
 148                         "Show version number.\n");
 149         fprintf(fp, "  -k, --kernel                       "
 150                         "Consumer kernel buffers (default).\n");
 151         fprintf(fp, "  -u, --ust                          "
 152                         "Consumer UST buffers.%s\n",
 153 #ifdef HAVE_LIBLTTNG_UST_CTL
 154                         ""
 155 #else
 156                         " (support not compiled in)"
 157 #endif
 158                         );
 159 }
 160
 161 /*
 162  * daemon argument parsing
 163  */
 164 static void parse_args(int argc, char **argv)
 165 {
 166         int c;
 167
 168         static struct option long_options[] = {
 169                 { "consumerd-cmd-sock", 1, 0, 'c' },
 170                 { "consumerd-err-sock", 1, 0, 'e' },
 171                 { "daemonize", 0, 0, 'd' },
 172                 { "help", 0, 0, 'h' },
 173                 { "quiet", 0, 0, 'q' },
 174                 { "verbose", 0, 0, 'v' },
 175                 { "version", 0, 0, 'V' },
 176                 { "kernel", 0, 0, 'k' },
 177 #ifdef HAVE_LIBLTTNG_UST_CTL
 178                 { "ust", 0, 0, 'u' },
 179 #endif
 180                 { NULL, 0, 0, 0 }
 181         };
 182
 183         while (1) {
 184                 int option_index = 0;
 185                 c = getopt_long(argc, argv, "dhqvVku" "c:e:", long_options, &option_index);
 186                 if (c == -1) {
 187                         break;
 188                 }
 189
 190                 switch (c) {
 191                 case 0:
 192                         fprintf(stderr, "option %s", long_options[option_index].name);
 193                         if (optarg) {
 194                                 fprintf(stderr, " with arg %s\n", optarg);
 195                         }
 196                         break;
 197                 case 'c':
 198                         snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 199                         break;
 200                 case 'e':
 201                         snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 202                         break;
 203                 case 'd':
 204                         opt_daemon = 1;
 205                         break;
 206                 case 'h':
 207                         usage(stdout);
 208                         exit(EXIT_SUCCESS);
 209                 case 'q':
 210                         lttng_opt_quiet = 1;
 211                         break;
 212                 case 'v':
 213                         lttng_opt_verbose = 1;
 214                         break;
 215                 case 'V':
 216                         fprintf(stdout, "%s\n", VERSION);
 217                         exit(EXIT_SUCCESS);
 218                 case 'k':
 219                         opt_type = LTTNG_CONSUMER_KERNEL;
 220                         break;
 221 #ifdef HAVE_LIBLTTNG_UST_CTL
 222                 case 'u':
 223 # if (CAA_BITS_PER_LONG == 64)
 224                         opt_type = LTTNG_CONSUMER64_UST;
 225 # elif (CAA_BITS_PER_LONG == 32)
 226                         opt_type = LTTNG_CONSUMER32_UST;
 227 # else
 228 #  error "Unknown bitness"
 229 # endif
 230                         break;
 231 #endif
 232                 default:
 233                         usage(stderr);
 234                         exit(EXIT_FAILURE);
 235                 }
 236         }
 237 }
 238
 239 /*
 240  * Set open files limit to unlimited. This daemon can open a large number of
 241  * file descriptors in order to consumer multiple kernel traces.
 242  */
 243 static void set_ulimit(void)
 244 {
 245         int ret;
 246         struct rlimit lim;
 247
 248         /* The kernel does not allowed an infinite limit for open files */
 249         lim.rlim_cur = 65535;
 250         lim.rlim_max = 65535;
 251
 252         ret = setrlimit(RLIMIT_NOFILE, &lim);
 253         if (ret < 0) {
 254                 PERROR("failed to set open files limit");
 255         }
 256 }
 257
 258 /*
 259  * main
 260  */
 261 int main(int argc, char **argv)
 262 {
 263         int ret = 0;
 264         void *status;
 265
 266         /* Parse arguments */
 267         progname = argv[0];
 268         parse_args(argc, argv);
 269
 270         /* Daemonize */
 271         if (opt_daemon) {
 272                 int i;
 273
 274                 /*
 275                  * fork
 276                  * child: setsid, close FD 0, 1, 2, chdir /
 277                  * parent: exit (if fork is successful)
 278                  */
 279                 ret = daemon(0, 0);
 280                 if (ret < 0) {
 281                         PERROR("daemon");
 282                         goto error;
 283                 }
 284                 /*
 285                  * We are in the child. Make sure all other file
 286                  * descriptors are closed, in case we are called with
 287                  * more opened file descriptors than the standard ones.
 288                  */
 289                 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
 290                         (void) close(i);
 291                 }
 292         }
 293
 294         /* Set up max poll set size */
 295         lttng_poll_set_max_size();
 296
 297         if (strlen(command_sock_path) == 0) {
 298                 switch (opt_type) {
 299                 case LTTNG_CONSUMER_KERNEL:
 300                         snprintf(command_sock_path, PATH_MAX, DEFAULT_KCONSUMERD_CMD_SOCK_PATH,
 301                                         DEFAULT_LTTNG_RUNDIR);
 302                         break;
 303                 case LTTNG_CONSUMER64_UST:
 304                         snprintf(command_sock_path, PATH_MAX,
 305                                         DEFAULT_USTCONSUMERD64_CMD_SOCK_PATH, DEFAULT_LTTNG_RUNDIR);
 306                         break;
 307                 case LTTNG_CONSUMER32_UST:
 308                         snprintf(command_sock_path, PATH_MAX,
 309                                         DEFAULT_USTCONSUMERD32_CMD_SOCK_PATH, DEFAULT_LTTNG_RUNDIR);
 310                         break;
 311                 default:
 312                         WARN("Unknown consumerd type");
 313                         goto error;
 314                 }
 315         }
 316
 317         /* Init */
 318         lttng_consumer_init();
 319
 320         if (!getuid()) {
 321                 /* Set limit for open files */
 322                 set_ulimit();
 323         }
 324
 325         /* create the consumer instance with and assign the callbacks */
 326         ctx = lttng_consumer_create(opt_type, lttng_consumer_read_subbuffer,
 327                 NULL, lttng_consumer_on_recv_stream, NULL);
 328         if (ctx == NULL) {
 329                 goto error;
 330         }
 331
 332         lttng_consumer_set_command_sock_path(ctx, command_sock_path);
 333         if (strlen(error_sock_path) == 0) {
 334                 switch (opt_type) {
 335                 case LTTNG_CONSUMER_KERNEL:
 336                         snprintf(error_sock_path, PATH_MAX, DEFAULT_KCONSUMERD_ERR_SOCK_PATH,
 337                                         DEFAULT_LTTNG_RUNDIR);
 338                         break;
 339                 case LTTNG_CONSUMER64_UST:
 340                         snprintf(error_sock_path, PATH_MAX,
 341                                         DEFAULT_USTCONSUMERD64_ERR_SOCK_PATH, DEFAULT_LTTNG_RUNDIR);
 342                         break;
 343                 case LTTNG_CONSUMER32_UST:
 344                         snprintf(error_sock_path, PATH_MAX,
 345                                         DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH, DEFAULT_LTTNG_RUNDIR);
 346                         break;
 347                 default:
 348                         WARN("Unknown consumerd type");
 349                         goto error;
 350                 }
 351         }
 352
 353         if (set_signal_handler() < 0) {
 354                 goto error;
 355         }
 356
 357         /* Connect to the socket created by lttng-sessiond to report errors */
 358         DBG("Connecting to error socket %s", error_sock_path);
 359         ret = lttcomm_connect_unix_sock(error_sock_path);
 360         /* not a fatal error, but all communication with lttng-sessiond will fail */
 361         if (ret < 0) {
 362                 WARN("Cannot connect to error socket (is lttng-sessiond started?)");
 363         }
 364         lttng_consumer_set_error_sock(ctx, ret);
 365
 366         /* Create thread to manage the polling/writing of trace metadata */
 367         ret = pthread_create(&metadata_thread, NULL, consumer_thread_metadata_poll,
 368                         (void *) ctx);
 369         if (ret != 0) {
 370                 perror("pthread_create");
 371                 goto error;
 372         }
 373
 374         /* Create thread to manage the polling/writing of trace data */
 375         ret = pthread_create(&data_thread, NULL, consumer_thread_data_poll,
 376                         (void *) ctx);
 377         if (ret != 0) {
 378                 perror("pthread_create");
 379                 goto data_error;
 380         }
 381
 382         /* Create the thread to manage the receive of fd */
 383         ret = pthread_create(&sessiond_thread, NULL, consumer_thread_sessiond_poll,
 384                         (void *) ctx);
 385         if (ret != 0) {
 386                 perror("pthread_create");
 387                 goto sessiond_error;
 388         }
 389
 390         ret = pthread_join(sessiond_thread, &status);
 391         if (ret != 0) {
 392                 perror("pthread_join");
 393                 goto error;
 394         }
 395
 396 sessiond_error:
 397         ret = pthread_join(data_thread, &status);
 398         if (ret != 0) {
 399                 perror("pthread_join");
 400                 goto error;
 401         }
 402
 403 data_error:
 404         ret = pthread_join(metadata_thread, &status);
 405         if (ret != 0) {
 406                 perror("pthread_join");
 407                 goto error;
 408         }
 409
 410         if (!ret) {
 411                 ret = EXIT_SUCCESS;
 412                 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_EXIT_SUCCESS);
 413                 goto end;
 414         }
 415
 416 error:
 417         ret = EXIT_FAILURE;
 418         lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_EXIT_FAILURE);
 419
 420 end:
 421         lttng_consumer_destroy(ctx);
 422         lttng_consumer_cleanup();
 423
 424         return ret;
 425 }