ltt-kconsumerd/ltt-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; only version 2
   8  * of the License.
   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 "kernelctl.h"
  42 #include "lttkconsumerd.h"
  43
  44 /* the two threads (receive fd and poll) */
  45 pthread_t threads[2];
  46
  47 /* to count the number of time the user pressed ctrl+c */
  48 static int sigintcount = 0;
  49
  50 /* Argument variables */
  51 int opt_quiet;
  52 int opt_verbose;
  53 static int opt_daemon;
  54 static const char *progname;
  55 char command_sock_path[PATH_MAX]; /* Global command socket path */
  56 char error_sock_path[PATH_MAX]; /* Global error path */
  57
  58 /*
  59  *  sighandler
  60  *
  61  *  Signal handler for the daemon
  62  */
  63 static void sighandler(int sig)
  64 {
  65         if (sig == SIGINT && sigintcount++ == 0) {
  66                 DBG("ignoring first SIGINT");
  67                 return;
  68         }
  69
  70         kconsumerd_should_exit();
  71 }
  72
  73 /*
  74  *  set_signal_handler
  75  *
  76  *  Setup signal handler for :
  77  *      SIGINT, SIGTERM, SIGPIPE
  78  */
  79 static int set_signal_handler(void)
  80 {
  81         int ret = 0;
  82         struct sigaction sa;
  83         sigset_t sigset;
  84
  85         if ((ret = sigemptyset(&sigset)) < 0) {
  86                 perror("sigemptyset");
  87                 return ret;
  88         }
  89
  90         sa.sa_handler = sighandler;
  91         sa.sa_mask = sigset;
  92         sa.sa_flags = 0;
  93         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
  94                 perror("sigaction");
  95                 return ret;
  96         }
  97
  98         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
  99                 perror("sigaction");
 100                 return ret;
 101         }
 102
 103         if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
 104                 perror("sigaction");
 105                 return ret;
 106         }
 107
 108         return ret;
 109 }
 110
 111 /*
 112  * usage function on stderr
 113  */
 114 static void usage(void)
 115 {
 116         fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
 117         fprintf(stderr, "  -h, --help                         "
 118                         "Display this usage.\n");
 119         fprintf(stderr, "  -c, --kconsumerd-cmd-sock PATH     "
 120                         "Specify path for the command socket\n");
 121         fprintf(stderr, "  -e, --kconsumerd-err-sock PATH     "
 122                         "Specify path for the error socket\n");
 123         fprintf(stderr, "  -d, --daemonize                    "
 124                         "Start as a daemon.\n");
 125         fprintf(stderr, "  -q, --quiet                        "
 126                         "No output at all.\n");
 127         fprintf(stderr, "  -v, --verbose                      "
 128                         "Verbose mode. Activate DBG() macro.\n");
 129         fprintf(stderr, "  -V, --version                      "
 130                         "Show version number.\n");
 131 }
 132
 133 /*
 134  * daemon argument parsing
 135  */
 136 static void parse_args(int argc, char **argv)
 137 {
 138         int c;
 139
 140         static struct option long_options[] = {
 141                 { "kconsumerd-cmd-sock", 1, 0, 'c' },
 142                 { "kconsumerd-err-sock", 1, 0, 'e' },
 143                 { "daemonize", 0, 0, 'd' },
 144                 { "help", 0, 0, 'h' },
 145                 { "quiet", 0, 0, 'q' },
 146                 { "verbose", 0, 0, 'v' },
 147                 { "version", 0, 0, 'V' },
 148                 { NULL, 0, 0, 0 }
 149         };
 150
 151         while (1) {
 152                 int option_index = 0;
 153                 c = getopt_long(argc, argv, "dhqvV" "c:e:", long_options, &option_index);
 154                 if (c == -1) {
 155                         break;
 156                 }
 157
 158                 switch (c) {
 159                 case 0:
 160                         fprintf(stderr, "option %s", long_options[option_index].name);
 161                         if (optarg) {
 162                                 fprintf(stderr, " with arg %s\n", optarg);
 163                         }
 164                         break;
 165                 case 'c':
 166                         snprintf(command_sock_path, PATH_MAX, "%s", optarg);
 167                         break;
 168                 case 'e':
 169                         snprintf(error_sock_path, PATH_MAX, "%s", optarg);
 170                         break;
 171                 case 'd':
 172                         opt_daemon = 1;
 173                         break;
 174                 case 'h':
 175                         usage();
 176                         exit(EXIT_FAILURE);
 177                 case 'q':
 178                         opt_quiet = 1;
 179                         break;
 180                 case 'v':
 181                         opt_verbose = 1;
 182                         break;
 183                 case 'V':
 184                         fprintf(stdout, "%s\n", VERSION);
 185                         exit(EXIT_SUCCESS);
 186                 default:
 187                         usage();
 188                         exit(EXIT_FAILURE);
 189                 }
 190         }
 191 }
 192
 193
 194 /*
 195  * main
 196  */
 197 int main(int argc, char **argv)
 198 {
 199         int i;
 200         int ret = 0;
 201         void *status;
 202
 203         /* Parse arguments */
 204         progname = argv[0];
 205         parse_args(argc, argv);
 206
 207         /* Daemonize */
 208         if (opt_daemon) {
 209                 ret = daemon(0, 0);
 210                 if (ret < 0) {
 211                         perror("daemon");
 212                         goto error;
 213                 }
 214         }
 215
 216         if (strlen(command_sock_path) == 0) {
 217                 snprintf(command_sock_path, PATH_MAX,
 218                                 KCONSUMERD_CMD_SOCK_PATH);
 219         }
 220         kconsumerd_set_command_socket_path(command_sock_path);
 221         if (strlen(error_sock_path) == 0) {
 222                 snprintf(error_sock_path, PATH_MAX,
 223                                 KCONSUMERD_ERR_SOCK_PATH);
 224         }
 225
 226         if (set_signal_handler() < 0) {
 227                 goto error;
 228         }
 229
 230         /* create the pipe to wake to receiving thread when needed */
 231         ret = kconsumerd_init();
 232         if (ret < 0) {
 233                 goto end;
 234         }
 235
 236         /* Connect to the socket created by ltt-sessiond to report errors */
 237         DBG("Connecting to error socket %s", error_sock_path);
 238         ret = lttcomm_connect_unix_sock(error_sock_path);
 239         /* not a fatal error, but all communication with ltt-sessiond will fail */
 240         if (ret < 0) {
 241                 WARN("Cannot connect to error socket, is ltt-sessiond started ?");
 242         }
 243         kconsumerd_set_error_socket(ret);
 244
 245         /* Create the thread to manage the receive of fd */
 246         ret = pthread_create(&threads[0], NULL, kconsumerd_thread_receive_fds,
 247                         (void *) NULL);
 248         if (ret != 0) {
 249                 perror("pthread_create");
 250                 goto error;
 251         }
 252
 253         /* Create thread to manage the polling/writing of traces */
 254         ret = pthread_create(&threads[1], NULL, kconsumerd_thread_poll_fds,
 255                         (void *) NULL);
 256         if (ret != 0) {
 257                 perror("pthread_create");
 258                 goto error;
 259         }
 260
 261         for (i = 0; i < 2; i++) {
 262                 ret = pthread_join(threads[i], &status);
 263                 if (ret != 0) {
 264                         perror("pthread_join");
 265                         goto error;
 266                 }
 267         }
 268         ret = EXIT_SUCCESS;
 269         kconsumerd_send_error(KCONSUMERD_EXIT_SUCCESS);
 270         goto end;
 271
 272 error:
 273         ret = EXIT_FAILURE;
 274         kconsumerd_send_error(KCONSUMERD_EXIT_FAILURE);
 275
 276 end:
 277         kconsumerd_cleanup();
 278
 279         return ret;
 280 }