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