kconsumerd/kconsumerd.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
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 #define _GNU_SOURCE
  21 #include <fcntl.h>
  22 #include <getopt.h>
  23 #include <grp.h>
  24 #include <limits.h>
  25 #include <pthread.h>
  26 #include <signal.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <sys/ipc.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
  40 #include "lttngerr.h"
  41 #include "libkernelctl.h"
  42 #include "liblttsessiondcomm.h"
  43 #include "liblttkconsumerd.h"
  44
  45 /* the two threads (receive fd and poll) */
  46 pthread_t threads[2];
  47
  48 /* to count the number of time the user pressed ctrl+c */
  49 static int sigintcount = 0;
  50
  51 /* Argument variables */
  52 int opt_quiet;
  53 int opt_verbose;
  54 static int opt_daemon;
  55 static const char *progname;
  56 char command_sock_path[PATH_MAX]; /* Global command socket path */
  57 char error_sock_path[PATH_MAX]; /* Global error path */
  58
  59 /*
  60  *  sighandler
  61  *
  62  *  Signal handler for the daemon
  63  */
  64 static void sighandler(int sig)
  65 {
  66         if (sig == SIGINT && sigintcount++ == 0) {
  67                 DBG("ignoring first SIGINT");
  68                 return;
  69         }
  70
  71         kconsumerd_cleanup();
  72 }
  73
  74 /*
  75  *  set_signal_handler
  76  *
  77  *  Setup signal handler for :
  78  *      SIGINT, SIGTERM, SIGPIPE
  79  */
  80 static int set_signal_handler(void)
  81 {
  82         int ret = 0;
  83         struct sigaction sa;
  84         sigset_t sigset;
  85
  86         if ((ret = sigemptyset(&sigset)) < 0) {
  87                 perror("sigemptyset");
  88                 return ret;
  89         }
  90
  91         sa.sa_handler = sighandler;
  92         sa.sa_mask = sigset;
  93         sa.sa_flags = 0;
  94         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
  95                 perror("sigaction");
  96                 return ret;
  97         }
  98
  99         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
 100                 perror("sigaction");
 101                 return ret;
 102         }
 103
 104         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 105                 perror("sigaction");
 106                 return ret;
 107         }
 108
 109         return ret;
 110 }
 111
 112 /*
 113  * usage function on stderr
 114  */
 115 static void usage(void)
 116 {
 117         fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 118         fprintf(stderr, "  -h, --help                         "
 119                         "Display this usage.\n");
 120         fprintf(stderr, "  -c, --kconsumerd-cmd-sock PATH     "
 121                         "Specify path for the command socket\n");
 122         fprintf(stderr, "  -e, --kconsumerd-err-sock PATH     "
 123                         "Specify path for the error socket\n");
 124         fprintf(stderr, "  -d, --daemonize                    "
 125                         "Start as a daemon.\n");
 126         fprintf(stderr, "  -q, --quiet                        "
 127                         "No output at all.\n");
 128         fprintf(stderr, "  -v, --verbose                      "
 129                         "Verbose mode. Activate DBG() macro.\n");
 130         fprintf(stderr, "  -V, --version                      "
 131                         "Show version number.\n");
 132 }
 133
 134 /*
 135  * daemon argument parsing
 136  */
 137 static void parse_args(int argc, char **argv)
 138 {
 139         int c;
 140
 141         static struct option long_options[] = {
 142                 { "kconsumerd-cmd-sock", 1, 0, 'c' },
 143                 { "kconsumerd-err-sock", 1, 0, 'e' },
 144                 { "daemonize", 0, 0, 'd' },
 145                 { "help", 0, 0, 'h' },
 146                 { "quiet", 0, 0, 'q' },
 147                 { "verbose", 0, 0, 'v' },
 148                 { "version", 0, 0, 'V' },
 149                 { NULL, 0, 0, 0 }
 150         };
 151
 152         while (1) {
 153                 int option_index = 0;
 154                 c = getopt_long(argc, argv, "dhqvV" "c:e:", long_options, &option_index);
 155                 if (c == -1) {
 156                         break;
 157                 }
 158
 159                 switch (c) {
 160                 case 0:
 161                         fprintf(stderr, "option %s", long_options[option_index].name);
 162                         if (optarg) {
 163                                 fprintf(stderr, " with arg %s\n", optarg);
 164                         }
 165                         break;
 166                 case 'c':
 167                         snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 168                         break;
 169                 case 'e':
 170                         snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 171                         break;
 172                 case 'd':
 173                         opt_daemon = 1;
 174                         break;
 175                 case 'h':
 176                         usage();
 177                         exit(EXIT_FAILURE);
 178                 case 'q':
 179                         opt_quiet = 1;
 180                         break;
 181                 case 'v':
 182                         opt_verbose = 1;
 183                         break;
 184                 case 'V':
 185                         fprintf(stdout, "%s\n", VERSION);
 186                         exit(EXIT_SUCCESS);
 187                 default:
 188                         usage();
 189                         exit(EXIT_FAILURE);
 190                 }
 191         }
 192 }
 193
 194
 195 /*
 196  * main
 197  */
 198 int main(int argc, char **argv)
 199 {
 200         int i;
 201         int ret = 0;
 202         void *status;
 203
 204         /* Parse arguments */
 205         progname = argv[0];
 206         parse_args(argc, argv);
 207
 208         /* Daemonize */
 209         if (opt_daemon) {
 210                 ret = daemon(0, 0);
 211                 if (ret < 0) {
 212                         perror("daemon");
 213                         goto error;
 214                 }
 215         }
 216
 217         if (strlen(command_sock_path) == 0) {
 218                 snprintf(command_sock_path, PATH_MAX,
 219                                 KCONSUMERD_CMD_SOCK_PATH);
 220         }
 221         kconsumerd_set_command_socket_path(command_sock_path);
 222         if (strlen(error_sock_path) == 0) {
 223                 snprintf(error_sock_path, PATH_MAX,
 224                                 KCONSUMERD_ERR_SOCK_PATH);
 225         }
 226
 227         if (set_signal_handler() < 0) {
 228                 goto error;
 229         }
 230
 231         /* create the pipe to wake to polling thread when needed */
 232         ret = kconsumerd_create_poll_pipe();
 233         if (ret < 0) {
 234                 perror("Error creating poll pipe");
 235                 goto end;
 236         }
 237
 238         /* Connect to the socket created by ltt-sessiond to report errors */
 239         DBG("Connecting to error socket %s", error_sock_path);
 240         ret = lttcomm_connect_unix_sock(error_sock_path);
 241         /* not a fatal error, but all communication with ltt-sessiond will fail */
 242         if (ret < 0) {
 243                 WARN("Cannot connect to error socket, is ltt-sessiond started ?");
 244         }
 245         kconsumerd_set_error_socket(ret);
 246
 247         /* Create the thread to manage the receive of fd */
 248         ret = pthread_create(&threads[0], NULL, kconsumerd_thread_receive_fds,
 249                         (void *) NULL);
 250         if (ret != 0) {
 251                 perror("pthread_create");
 252                 goto error;
 253         }
 254
 255         /* Create thread to manage the polling/writing of traces */
 256         ret = pthread_create(&threads[1], NULL, kconsumerd_thread_poll_fds,
 257                         (void *) NULL);
 258         if (ret != 0) {
 259                 perror("pthread_create");
 260                 goto error;
 261         }
 262
 263         for (i = 0; i < 2; i++) {
 264                 ret = pthread_join(threads[i], &status);
 265                 if (ret != 0) {
 266                         perror("pthread_join");
 267                         goto error;
 268                 }
 269         }
 270         ret = EXIT_SUCCESS;
 271         kconsumerd_send_error(KCONSUMERD_EXIT_SUCCESS);
 272         goto end;
 273
 274 error:
 275         ret = EXIT_FAILURE;
 276         kconsumerd_send_error(KCONSUMERD_EXIT_FAILURE);
 277
 278 end:
 279         kconsumerd_cleanup();
 280
 281         return ret;
 282 }