/*
    gvpectrl.C -- the main file for gvpectrl
    Copyright (C) 1998-2002 Ivo Timmermans <ivo@o2w.nl>
                  2000-2002 Guus Sliepen <guus@sliepen.eu.org>
                  2003-2005 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 2 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 gvpe; if not, write to the Free Software
    Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "config.h"

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

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

#include <openssl/rand.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>
#include <openssl/evp.h>

#include "pidfile.h"

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

/* 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, it will attempt to kill a running gvpe and exit. */
static int kill_gvpe;

/* If nonzero, it will attempt to kill a running gvpe and exit. */
static int show_config;

/* If nonzero, generate public/private keypair for this net. */
static int generate_keys;

static struct option const long_options[] =
    {
      {"config", required_argument, NULL, 'c'},
      {"kill", optional_argument, NULL, 'k'},
      {"help", no_argument, &show_help, 1},
      {"version", no_argument, &show_version, 1},
      {"generate-keys", no_argument, NULL, 'g'},
      {"show-config", no_argument, &show_config, 's'},
      {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]...\n\n"), get_identity ());
      printf (_
              ("  -c, --config=DIR           Read configuration options from DIR.\n"
               "  -k, --kill[=SIGNAL]        Attempt to kill a running gvpe and exit.\n"
               "  -g, --generate-keys        Generate public/private RSA keypair.\n"
               "  -s, --show-config          Display the configuration information.\n"
               "      --help                 Display this help and exit.\n"
               "      --version              Output version information and exit.\n\n"));
      printf (_("Report bugs to <vpe@plan9.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:k::gs", long_options,
                         &option_index)) != EOF)
    {
      switch (r)
        {
        case 0:		/* long option */
          break;

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

        case 'k':		/* kill old gvpes */
          if (optarg)
            {
              if (!strcasecmp (optarg, "HUP"))
                kill_gvpe = SIGHUP;
              else if (!strcasecmp (optarg, "TERM"))
                kill_gvpe = SIGTERM;
              else if (!strcasecmp (optarg, "KILL"))
                kill_gvpe = SIGKILL;
              else if (!strcasecmp (optarg, "USR1"))
                kill_gvpe = SIGUSR1;
              else if (!strcasecmp (optarg, "USR2"))
                kill_gvpe = SIGUSR2;
              else if (!strcasecmp (optarg, "INT"))
                kill_gvpe = SIGINT;
              else if (!strcasecmp (optarg, "ALRM"))
                kill_gvpe = SIGALRM;
              else
                {
                  kill_gvpe = atoi (optarg);

                  if (!kill_gvpe)
                    {
                      fprintf (stderr,
                               _
                               ("Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n"),
                               optarg);
                      usage (1);
                    }
                }
            }
          else
            kill_gvpe = SIGTERM;

          break;

        case 'g':		/* generate public/private keypair */
          generate_keys = RSA_KEYBITS;
          break;

        case 's':
          show_config = 1;
          break;

        case '?':
          usage (1);

        default:
          break;
        }
    }
}

/* This function prettyprints the key generation process */

void
indicator (int a, int b, void *p)
{
  switch (a)
    {
    case 0:
      fprintf (stderr, ".");
      break;

    case 1:
      fprintf (stderr, "+");
      break;

    case 2:
      fprintf (stderr, "-");
      break;

    case 3:
      switch (b)
        {
        case 0:
          fprintf (stderr, " p\n");
          break;

        case 1:
          fprintf (stderr, " q\n");
          break;

        default:
          fprintf (stderr, "?");
        }
      break;

    default:
      fprintf (stderr, "?");
    }
}

/*
 * generate public/private RSA keypairs for all hosts that don't have one.
 */
int
keygen (int bits)
{
  RSA *rsa_key;
  FILE *f;
  char *name = NULL;
  char *fname;

  asprintf (&fname, "%s/hostkeys", confbase);
  mkdir (fname, 0700);
  free (fname);

  asprintf (&fname, "%s/pubkey", confbase);
  mkdir (fname, 0700);
  free (fname);

  for (configuration::node_vector::iterator i = conf.nodes.begin (); i != conf.nodes.end (); ++i)
    {
      conf_node *node = *i;

      asprintf (&fname, "%s/pubkey/%s", confbase, node->nodename);

      f = fopen (fname, "a");

      if (!f)
        {
          perror (fname);
          exit (EXIT_FAILURE);
        }

      if (ftell (f))
        {
          fprintf (stderr, "'%s' already exists, skipping this node\n",
                   fname);
          fclose (f);
          continue;
        }

      fprintf (stderr, _("generating %d bits key for %s:\n"), bits,
               node->nodename);

      rsa_key = RSA_generate_key (bits, 0xFFFF, indicator, NULL);

      if (!rsa_key)
        {
          fprintf (stderr, _("error during key generation!\n"));
          return -1;
        }
      else
        fprintf (stderr, _("Done.\n"));

      require (PEM_write_RSAPublicKey (f, rsa_key));
      fclose (f);
      free (fname);

      asprintf (&fname, "%s/hostkeys/%s", confbase, node->nodename);

      f = fopen (fname, "a");
      if (!f)
        {
          perror (fname);
          exit (EXIT_FAILURE);
        }

      require (PEM_write_RSAPrivateKey (f, rsa_key, NULL, NULL, 0, NULL, NULL));
      fclose (f);
      free (fname);
    }

  return 0;
}

int
main (int argc, char **argv, char **envp)
{
  set_identity (argv[0]);
  log_to (LOGTO_STDERR);

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

  parse_options (argc, argv, envp);

  if (show_version)
    {
      printf (_("%s version %s (built %s %s, protocol %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 Marc Lehmann <vpe@plan9.de> and others.\n"
               "See the AUTHORS file for a complete list.\n\n"
               "vpe 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);

  conf.read_config (false);

  if (generate_keys)
    {
      RAND_load_file ("/dev/urandom", 1024);
      exit (keygen (generate_keys));
    }

  if (kill_gvpe)
    exit (kill_other (kill_gvpe));

  if (show_config)
    {
      conf.print ();
      exit (EXIT_SUCCESS);
    }

  usage (1);
}