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