/*
    gvpe.C -- the main file for gvpe
    Copyright (C) 1998-2002 Ivo Timmermans <ivo@o2w.nl>
                  2000-2002 Guus Sliepen <guus@sliepen.eu.org>
                  2003-2008 Marc Lehmann <gvpe@schmorp.de>
 
    This file is part of GVPE.

    GVPE is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation; either version 3 of the License, or (at your
    option) any later version.
   
    This program is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
    Public License for more details.
   
    You should have received a copy of the GNU General Public License along
    with this program; if not, see <http://www.gnu.org/licenses/>.
   
    Additional permission under GNU GPL version 3 section 7
   
    If you modify this Program, or any covered work, by linking or
    combining it with the OpenSSL project's OpenSSL library (or a modified
    version of that library), containing parts covered by the terms of the
    OpenSSL or SSLeay licenses, the licensors of this Program grant you
    additional permission to convey the resulting work.  Corresponding
    Source for a non-source form of such a combination shall include the
    source code for the parts of OpenSSL used as well as that of the
    covered work.
*/

#include "config.h"

#include <cstdio>
#include <cstring>
#include <cstdlib>

#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <termios.h>

#if HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif

#include <openssl/err.h>
#include <openssl/rand.h>

#include "gettext.h"
#include "pidfile.h"

#include "conf.h"
#include "slog.h"
#include "util.h"
#include "vpn.h"
#include "ev_cpp.h"

static loglevel llevel = L_NONE;

/* If nonzero, display usage information and exit. */
static int show_help;

/* If nonzero, print the version on standard output and exit.  */
static int show_version;

/* If nonzero, disable swapping for this process. */
static int do_mlock = 0;

/* If zero, don't detach from the terminal. */
static int do_detach = 1;

static struct option const long_options[] =
    {
      {"config", required_argument, NULL, 'c'},
      {"help", no_argument, &show_help, 1},
      {"version", no_argument, &show_version, 1},
      {"no-detach", no_argument, &do_detach, 0},
      {"log-level", required_argument, NULL, 'l'},
      {"mlock", no_argument, &do_mlock, 1},
      {NULL, 0, NULL, 0}
    };

static void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help\' for more information.\n"), get_identity ());
  else
    {
      printf (_("Usage: %s [option]... NODENAME\n\n"), get_identity ());
      printf (_
              ("  -c, --config=DIR           Read configuration options from DIR.\n"
               "  -D, --no-detach            Don't fork and detach.\n"
               "  -l, --log-level=LEVEL      Set logging level (info, notice, warn are common).\n"
               "  -L, --mlock                Lock gvpe into main memory.\n"
               "      --help                 Display this help and exit.\n"
               "      --version              Output version information and exit.\n\n"));
      printf (_("Report bugs to <gvpe@schmorp.de>.\n"));
    }

  exit (status);
}

void
parse_options (int argc, char **argv, char **envp)
{
  int r;
  int option_index = 0;

  while ((r = getopt_long (argc, argv, "c:DLl:", long_options, &option_index)) != EOF)
    {
      switch (r)
        {
        case 0:		/* long option */
          break;

        case 'c':		/* config file */
          confbase = strdup (optarg);
          break;

        case 'D':		/* no detach */
          do_detach = 0;
          break;

        case 'L':		/* lock into memory */
          do_mlock = 1;
          break;

        case 'l':		/* inc debug level */
          {
            llevel = string_to_loglevel (optarg);

            if (llevel == L_NONE)
              slog (L_WARN, "'%s': %s", optarg, UNKNOWN_LOGLEVEL);
          }
          break;

        case '?':
          usage (1);

        default:
          break;
        }
    }
}

/*
  Close network connections, and terminate neatly
*/
void cleanup_and_exit(int c)
{
  network.shutdown_all ();

  if (conf.pidfilename)
    remove_pid (conf.pidfilename);

  slog (L_INFO, _("terminating with exit code %d"), c);

  exit (c);
}

/*
  Signal handlers.
*/
RETSIGTYPE
sigterm_handler (int a)
{
  network.events |= vpn::EVENT_SHUTDOWN;
  network.event.start ();
}

RETSIGTYPE
sighup_handler (int a)
{
  network.events |= vpn::EVENT_RECONNECT;
  network.event.start ();
}

RETSIGTYPE
sigusr1_handler (int a)
{
  network.dump_status ();
}

RETSIGTYPE
sigusr2_handler (int a)
{
}

void
setup_signals (void)
{
  struct sigaction act;

  sigfillset (&act.sa_mask);
  act.sa_flags = 0;

  act.sa_handler = sighup_handler;  sigaction (SIGHUP , &act, NULL);
  act.sa_handler = sigusr1_handler; sigaction (SIGUSR1, &act, NULL);
  act.sa_handler = sigusr2_handler; sigaction (SIGUSR2, &act, NULL);
  act.sa_handler = SIG_IGN;         sigaction (SIGPIPE, &act, NULL);
  act.sa_flags = SA_RESETHAND;
  act.sa_handler = sigterm_handler; sigaction (SIGINT , &act, NULL);
  act.sa_handler = sigterm_handler; sigaction (SIGTERM, &act, NULL);
}

int
main (int argc, char **argv, char **envp)
{
  ERR_load_crypto_strings (); // we have the RAM

  set_loglevel (L_INFO);
  set_identity (argv[0]);
  log_to (LOGTO_SYSLOG | LOGTO_STDERR);

  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  parse_options (argc, argv, envp);

  argc -= optind;
  argv += optind;

  if (show_version)
    {
      printf (_("%s version %s (built %s %s, protocol version %d.%d)\n"), get_identity (),
              VERSION, __DATE__, __TIME__, PROTOCOL_MAJOR, PROTOCOL_MINOR);
      printf (_("Built with kernel interface %s/%s.\n"), IFTYPE, IFSUBTYPE);
      printf (_
              ("Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de> and others.\n"
               "See the AUTHORS file for a complete list.\n\n"
               "GVPE comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
               "and you are welcome to redistribute it under certain conditions;\n"
               "see the file COPYING for details.\n"));

      return 0;
    }

  if (show_help)
    usage (0);

  log_to (LOGTO_SYSLOG | LOGTO_STDERR);

  /* Lock all pages into memory if requested */

#if HAVE_MLOCKALL && HAVE_SYS_MMAN_H && _POSIX_MEMLOCK
  if (do_mlock)
    if (mlockall (MCL_CURRENT | MCL_FUTURE))
      slog (L_ERR, _("system call `%s' failed: %s"), "mlockall", strerror (errno));
#endif

  if (argc >= 1)
    {
      thisnode = *argv++;
      argc--;
    }

  if (!ev_default_loop (0))
    {
      slog (L_ERR, _("unable to initialise the event loop (bad $LIBEV_METHODS?)"));
      exit (EXIT_FAILURE);
    }

  {
    configuration_parser (conf, true, argc, argv);
  }

  set_loglevel (llevel != L_NONE ? llevel : conf.llevel);

  RAND_load_file ("/dev/urandom", 1024);

  if (!THISNODE)
    {
      slog (L_ERR, _("current node not set, or node '%s' not found in configfile, specify the nodename when starting gvpe."),
            thisnode ? thisnode : "<unset>");
      exit (EXIT_FAILURE);
    }

  if (detach (do_detach))
    exit (EXIT_SUCCESS);

  setup_signals ();

  if (!network.setup ())
    {
      ev_loop (EV_DEFAULT_ 0);
      cleanup_and_exit (EXIT_FAILURE);
    }

  slog (L_ERR, _("unrecoverable error while setting up network, exiting."));
  cleanup_and_exit (EXIT_FAILURE);
}