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