path: root/init.c

/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  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 (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef WIN32
#include "config-win32.h"
#else
#include "config.h"
#endif

#include "syshead.h"

#include "win32.h"
#include "init.h"
#include "sig.h"
#include "occ.h"
#include "list.h"
#include "otime.h"
#include "pool.h"
#include "gremlin.h"
#include "pkcs11.h"
#include "ps.h"

#include "memdbg.h"

#include "occ-inline.h"

/*
 * Crypto initialization flags
 */
#define CF_LOAD_PERSISTED_PACKET_ID (1<<0)
#define CF_INIT_TLS_MULTI           (1<<1)
#define CF_INIT_TLS_AUTH_STANDALONE (1<<2)

static void do_init_first_time (struct context *c);

void
context_clear (struct context *c)
{
  CLEAR (*c);
}

void
context_clear_1 (struct context *c)
{
  CLEAR (c->c1);
}

void
context_clear_2 (struct context *c)
{
  CLEAR (c->c2);
}

void
context_clear_all_except_first_time (struct context *c)
{
  const bool first_time_save = c->first_time;
  const struct context_persist cpsave = c->persist;
  context_clear (c);
  c->first_time = first_time_save;
  c->persist = cpsave;
}

/*
 * Initialize and possibly randomize remote list.
 */
static void
init_remote_list (struct context *c)
{
  c->c1.remote_list = NULL;

  if (c->options.remote_list)
    {
      struct remote_list *l;
      ALLOC_OBJ_GC (c->c1.remote_list, struct remote_list, &c->gc);
      l = c->c1.remote_list;
      *l = *c->options.remote_list;
      l->current = -1;
      if (c->options.remote_random)
	remote_list_randomize (l);
    }
}

/*
 * Query for private key and auth-user-pass username/passwords
 */
static void
init_query_passwords (struct context *c)
{
#if defined(USE_CRYPTO) && defined(USE_SSL)
  /* Certificate password input */
  if (c->options.key_pass_file)
    pem_password_setup (c->options.key_pass_file);
#endif
  
#if P2MP
  /* Auth user/pass input */
  if (c->options.auth_user_pass_file)
    auth_user_pass_setup (c->options.auth_user_pass_file);
#endif
}

void
context_init_1 (struct context *c)
{
#ifdef ENABLE_HTTP_PROXY
  bool did_http = false;
#else
  const bool did_http = false;
#endif

  context_clear_1 (c);

  packet_id_persist_init (&c->c1.pid_persist);
  init_remote_list (c);

  init_query_passwords (c);

#if defined(ENABLE_PKCS11)
  if (c->first_time) {
    int i;
    pkcs11_initialize (c->options.pkcs11_pin_cache_period);
    for (i=0;i<MAX_PARMS && c->options.pkcs11_providers[i] != NULL;i++)
     pkcs11_addProvider (c->options.pkcs11_providers[i], c->options.pkcs11_sign_mode[i]);
  }
#endif

#if 0 /* test get_user_pass with GET_USER_PASS_NEED_OK flag */
 {
   /*
    * In the management interface, you can okay the request by entering "needok token-insertion-request ok"
    */
   struct user_pass up;
   CLEAR (up);
   strcpy (up.username, "Please insert your cryptographic token"); /* put the high-level message in up.username */
   get_user_pass (&up, NULL, "token-insertion-request", GET_USER_PASS_MANAGEMENT|GET_USER_PASS_NEED_OK);
   msg (M_INFO, "RET:%s", up.password); /* will return the third argument to management interface
                                           'needok' command, usually 'ok' or 'cancel'. */
 }
#endif

#ifdef ENABLE_HTTP_PROXY
  if (c->options.http_proxy_options || c->options.auto_proxy_info)
    {
      /* Possible HTTP proxy user/pass input */
      c->c1.http_proxy = new_http_proxy (c->options.http_proxy_options,
					 c->options.auto_proxy_info,
					 &c->gc);
      if (c->c1.http_proxy)
	did_http = true;
    }
#endif

#ifdef ENABLE_SOCKS
  if (!did_http && (c->options.socks_proxy_server || c->options.auto_proxy_info))
    {
      c->c1.socks_proxy = new_socks_proxy (c->options.socks_proxy_server,
					   c->options.socks_proxy_port,
					   c->options.socks_proxy_retry,
					   c->options.auto_proxy_info,
					   &c->gc);
    }
#endif
}

void
context_gc_free (struct context *c)
{
  gc_free (&c->c2.gc);
  gc_free (&c->options.gc);
  gc_free (&c->gc);
}

#if PORT_SHARE

static void
close_port_share (void)
{
  if (port_share)
    {
      port_share_close (port_share);
      port_share = NULL;
    }
}

static void
init_port_share (struct context *c)
{
  if (!port_share && (c->options.port_share_host && c->options.port_share_port))
    {
      port_share = port_share_open (c->options.port_share_host,
				    c->options.port_share_port);
      if (port_share == NULL)
	msg (M_FATAL, "Fatal error: Port sharing failed");
    }
}

#endif

bool
init_static (void)
{
  configure_path ();

#if defined(USE_CRYPTO) && defined(DMALLOC)
  openssl_dmalloc_init ();
#endif

  init_random_seed ();		/* init random() function, only used as
				   source for weak random numbers */
  error_reset ();		/* initialize error.c */
  reset_check_status ();	/* initialize status check code in socket.c */

#ifdef WIN32
  init_win32 ();
#endif

#ifdef OPENVPN_DEBUG_COMMAND_LINE
  {
    int i;
    for (i = 0; i < argc; ++i)
      msg (M_INFO, "argv[%d] = '%s'", i, argv[i]);
  }
#endif

  update_time ();

#ifdef USE_CRYPTO
  init_ssl_lib ();

  /* init PRNG used for IV generation */
  /* When forking, copy this to more places in the code to avoid fork
     random-state predictability */
  prng_init ();
#endif

#ifdef PID_TEST
  packet_id_interactive_test ();	/* test the sequence number code */
  return false;
#endif

#ifdef SCHEDULE_TEST
  schedule_test ();
  return false;
#endif

#ifdef LIST_TEST
  list_test ();
  return false;
#endif

#ifdef IFCONFIG_POOL_TEST
  ifconfig_pool_test (0x0A010004, 0x0A0100FF);
  return false;
#endif

#ifdef CHARACTER_CLASS_DEBUG
  character_class_debug ();
  return false;
#endif

#ifdef EXTRACT_X509_FIELD_TEST
  extract_x509_field_test ();
  return false;
#endif

  return true;
}

void
uninit_static (void)
{
  openvpn_thread_cleanup ();

#ifdef USE_CRYPTO
  free_ssl_lib ();
#endif

#ifdef ENABLE_PKCS11
  pkcs11_terminate ();
#endif

#if PORT_SHARE
  close_port_share ();
#endif

#if defined(MEASURE_TLS_HANDSHAKE_STATS) && defined(USE_CRYPTO) && defined(USE_SSL)
  show_tls_performance_stats ();
#endif
}

void
init_verb_mute (struct context *c, unsigned int flags)
{
  if (flags & IVM_LEVEL_1)
    {
      /* set verbosity and mute levels */
      set_check_status (D_LINK_ERRORS, D_READ_WRITE);
      set_debug_level (c->options.verbosity, SDL_CONSTRAIN);
      set_mute_cutoff (c->options.mute);
    }

  /* special D_LOG_RW mode */
  if (flags & IVM_LEVEL_2)
    c->c2.log_rw = (check_debug_level (D_LOG_RW) && !check_debug_level (D_LOG_RW + 1));
}

/*
 * Possibly set --dev based on --dev-node.
 * For example, if --dev-node /tmp/foo/tun, and --dev undefined,
 * set --dev to tun.
 */
void
init_options_dev (struct options *options)
{
  if (!options->dev)
    options->dev = dev_component_in_dev_node (options->dev_node);
}

bool
print_openssl_info (const struct options *options)
{
  /*
   * OpenSSL info print mode?
   */
#ifdef USE_CRYPTO
  if (options->show_ciphers || options->show_digests || options->show_engines
#ifdef USE_SSL
      || options->show_tls_ciphers
#endif
    )
    {
      if (options->show_ciphers)
	show_available_ciphers ();
      if (options->show_digests)
	show_available_digests ();
      if (options->show_engines)
	show_available_engines ();
#ifdef USE_SSL
      if (options->show_tls_ciphers)
	show_available_tls_ciphers ();
#endif
      return true;
    }
#endif
  return false;
}

/*
 * Static pre-shared key generation mode?
 */
bool
do_genkey (const struct options * options)
{
#ifdef USE_CRYPTO
  if (options->genkey)
    {
      int nbits_written;

      notnull (options->shared_secret_file,
	       "shared secret output file (--secret)");

      if (options->mlock)	/* should we disable paging? */
	do_mlockall (true);

      nbits_written = write_key_file (2, options->shared_secret_file);

      msg (D_GENKEY | M_NOPREFIX,
	   "Randomly generated %d bit key written to %s", nbits_written,
	   options->shared_secret_file);
      return true;
    }
#endif
  return false;
}

/*
 * Persistent TUN/TAP device management mode?
 */
bool
do_persist_tuntap (const struct options *options)
{
#ifdef TUNSETPERSIST
  if (options->persist_config)
    {
      /* sanity check on options for --mktun or --rmtun */
      notnull (options->dev, "TUN/TAP device (--dev)");
      if (options->remote_list || options->ifconfig_local
	  || options->ifconfig_remote_netmask
#ifdef USE_CRYPTO
	  || options->shared_secret_file
#ifdef USE_SSL
	  || options->tls_server || options->tls_client
#endif
#endif
	)
	msg (M_FATAL|M_OPTERR,
	     "options --mktun or --rmtun should only be used together with --dev");
      tuncfg (options->dev, options->dev_type, options->dev_node,
	      options->tun_ipv6, options->persist_mode);
      return true;
    }
#endif
  return false;
}

/*
 * Should we become a daemon?
 * Return true if we did it.
 */
static bool
possibly_become_daemon (const struct options *options, const bool first_time)
{
  bool ret = false;
  if (first_time && options->daemon)
    {
      ASSERT (!options->inetd);
      if (daemon (options->cd_dir != NULL, options->log) < 0)
	msg (M_ERR, "daemon() failed");
      if (options->log)
	set_std_files_to_null (true);

#if defined(ENABLE_PKCS11)
      pkcs11_forkFixup ();
#endif

      ret = true;
    }
  return ret;
}

/*
 * Actually do UID/GID downgrade, and chroot, if requested.
 */
static void
do_uid_gid_chroot (struct context *c, bool no_delay)
{
  static const char why_not[] = "will be delayed because of --client, --pull, or --up-delay";
  struct context_0 *c0 = c->c0;

  if (c->first_time && c0 && !c0->uid_gid_set)
    {
      /* chroot if requested */
      if (c->options.chroot_dir)
	{
	  if (no_delay)
	    do_chroot (c->options.chroot_dir);
	  else
	    msg (M_INFO, "NOTE: chroot %s", why_not);
	}

      /* set user and/or group that we want to setuid/setgid to */
      if (no_delay)
	{
	  set_group (&c0->group_state);
	  set_user (&c0->user_state);
	  c0->uid_gid_set = true;
	}
      else if (c0->uid_gid_specified)
	{
	  msg (M_INFO, "NOTE: UID/GID downgrade %s", why_not);
	}
    }
}

/*
 * Return common name in a way that is formatted for
 * prepending to msg() output.
 */
const char *
format_common_name (struct context *c, struct gc_arena *gc)
{
  struct buffer out = alloc_buf_gc (256, gc);
#if defined(USE_CRYPTO) && defined(USE_SSL)
  if (c->c2.tls_multi)
    {
      buf_printf (&out, "[%s] ", tls_common_name (c->c2.tls_multi, false));
    }
#endif
  return BSTR (&out);
}

void
pre_setup (const struct options *options)
{
#ifdef WIN32
  if (options->exit_event_name)
    {
      win32_signal_open (&win32_signal,
			 WSO_FORCE_SERVICE,
			 options->exit_event_name,
			 options->exit_event_initial_state);
    }
  else
    {
      win32_signal_open (&win32_signal,
			 WSO_FORCE_CONSOLE,
			 NULL,
			 false);

      /* put a title on the top window bar */
      if (win32_signal.mode == WSO_MODE_CONSOLE)
	{
	  window_title_save (&window_title); 
	  window_title_generate (options->config);
	}
    }
#endif
}

void
reset_coarse_timers (struct context *c)
{
  c->c2.coarse_timer_wakeup = 0;
}

/*
 * Initialize timers
 */
static void
do_init_timers (struct context *c, bool deferred)
{
  update_time ();
  reset_coarse_timers (c);

  /* initialize inactivity timeout */
  if (c->options.inactivity_timeout)
    event_timeout_init (&c->c2.inactivity_interval, c->options.inactivity_timeout, now);

  /* initialize pings */

  if (c->options.ping_send_timeout)
    event_timeout_init (&c->c2.ping_send_interval, c->options.ping_send_timeout, 0);

  if (c->options.ping_rec_timeout)
    event_timeout_init (&c->c2.ping_rec_interval, c->options.ping_rec_timeout, now);

  if (!deferred)
    {
      /* initialize connection establishment timer */
      event_timeout_init (&c->c2.wait_for_connect, 1, now);

#ifdef ENABLE_OCC
      /* initialize occ timers */

      if (c->options.occ
	  && !TLS_MODE (c)
	  && c->c2.options_string_local && c->c2.options_string_remote)
	event_timeout_init (&c->c2.occ_interval, OCC_INTERVAL_SECONDS, now);

      if (c->options.mtu_test)
	event_timeout_init (&c->c2.occ_mtu_load_test_interval, OCC_MTU_LOAD_INTERVAL_SECONDS, now);
#endif

      /* initialize packet_id persistence timer */
#ifdef USE_CRYPTO
      if (c->options.packet_id_file)
	event_timeout_init (&c->c2.packet_id_persist_interval, 60, now);
#endif

#if defined(USE_CRYPTO) && defined(USE_SSL)
      /* initialize tmp_int optimization that limits the number of times we call
	 tls_multi_process in the main event loop */
      interval_init (&c->c2.tmp_int, TLS_MULTI_HORIZON, TLS_MULTI_REFRESH);
#endif
    }
}

/*
 * Initialize traffic shaper.
 */
static void
do_init_traffic_shaper (struct context *c)
{
#ifdef HAVE_GETTIMEOFDAY
  /* initialize traffic shaper (i.e. transmit bandwidth limiter) */
  if (c->options.shaper)
    {
      shaper_init (&c->c2.shaper, c->options.shaper);
      shaper_msg (&c->c2.shaper);
    }
#endif
}

/*
 * Allocate a route list structure if at least one
 * --route option was specified.
 */
static void
do_alloc_route_list (struct context *c)
{
  if (c->options.routes && !c->c1.route_list)
    c->c1.route_list = new_route_list (&c->gc);
}


/*
 * Initialize the route list, resolving any DNS names in route
 * options and saving routes in the environment.
 */
static void
do_init_route_list (const struct options *options,
		    struct route_list *route_list,
		    const struct link_socket_info *link_socket_info,
		    bool fatal,
		    struct env_set *es)
{
  const char *gw = NULL;
  int dev = dev_type_enum (options->dev, options->dev_type);

  if (dev == DEV_TYPE_TUN && (options->topology == TOP_NET30 || options->topology == TOP_P2P))
    gw = options->ifconfig_remote_netmask;
  if (options->route_default_gateway)
    gw = options->route_default_gateway;

  if (!init_route_list (route_list,
			options->routes,
			gw,
			link_socket_current_remote (link_socket_info),
			es))
    {
      if (fatal)
	openvpn_exit (OPENVPN_EXIT_STATUS_ERROR);	/* exit point */
    }
  else
    {
      /* copy routes to environment */
      setenv_routes (es, route_list);
    }
}

/*
 * Called after all initialization has been completed.
 */
void
initialization_sequence_completed (struct context *c, const unsigned int flags)
{
  static const char message[] = "Initialization Sequence Completed";

  /* If we delayed UID/GID downgrade or chroot, do it now */
  do_uid_gid_chroot (c, true);

  /* Test if errors */
  if (flags & ISC_ERRORS)
    {
#ifdef WIN32
      show_routes (M_INFO|M_NOPREFIX);
      show_adapters (M_INFO|M_NOPREFIX);
      msg (M_INFO, "%s With Errors ( see http://openvpn.net/faq.html#dhcpclientserv )", message);
#else
      msg (M_INFO, "%s With Errors", message);
#endif
    }
  else
    msg (M_INFO, "%s", message);

  /* Flag remote_list that we initialized */
  if ((flags & (ISC_ERRORS|ISC_SERVER)) == 0 && c->c1.remote_list && c->c1.remote_list->len > 1)
    c->c1.remote_list->no_advance = true;

#ifdef ENABLE_MANAGEMENT
  /* Tell management interface that we initialized */
  if (management)
    {
      in_addr_t tun_local = 0;
      in_addr_t tun_remote = 0; /* FKS */
      const char *detail = "SUCCESS";
      if (c->c1.tuntap)
	tun_local = c->c1.tuntap->local;
      tun_remote = htonl (c->c1.link_socket_addr.actual.dest.sa.sin_addr.s_addr);
      if (flags & ISC_ERRORS)
	detail = "ERROR";
      management_set_state (management,
			    OPENVPN_STATE_CONNECTED,
			    detail,
			    tun_local,
			    tun_remote);
      if (tun_local)
	management_post_tunnel_open (management, tun_local);
    }
#endif

}

/*
 * Possibly add routes and/or call route-up script
 * based on options.
 */
void
do_route (const struct options *options,
	  struct route_list *route_list,
	  const struct tuntap *tt,
	  const struct plugin_list *plugins,
	  struct env_set *es)
{
  if (!options->route_noexec && route_list)
    add_routes (route_list, tt, ROUTE_OPTION_FLAGS (options), es);

  if (plugin_defined (plugins, OPENVPN_PLUGIN_ROUTE_UP))
    {
      if (plugin_call (plugins, OPENVPN_PLUGIN_ROUTE_UP, NULL, NULL, es))
	msg (M_WARN, "WARNING: route-up plugin call failed");
    }

  if (options->route_script)
    {
      setenv_str (es, "script_type", "route-up");
      system_check (options->route_script, es, S_SCRIPT, "Route script failed");
    }

#ifdef WIN32
  if (options->show_net_up)
    {
      show_routes (M_INFO|M_NOPREFIX);
      show_adapters (M_INFO|M_NOPREFIX);
    }
  else if (check_debug_level (D_SHOW_NET))
    {
      show_routes (D_SHOW_NET|M_NOPREFIX);
      show_adapters (D_SHOW_NET|M_NOPREFIX);
    }
#endif
}

/*
 * Save current pulled options string in the c1 context store, so we can
 * compare against it after possible future restarts.
 */
#if P2MP
static void
save_pulled_options_string (struct context *c, const char *newstring)
{
  if (c->c1.pulled_options_string_save)
    free (c->c1.pulled_options_string_save);

  c->c1.pulled_options_string_save = NULL;

  if (newstring)
    c->c1.pulled_options_string_save = string_alloc (newstring, NULL);
}
#endif

/*
 * initialize tun/tap device object
 */
static void
do_init_tun (struct context *c)
{
  c->c1.tuntap = init_tun (c->options.dev,
			   c->options.dev_type,
			   c->options.topology,
			   c->options.ifconfig_local,
			   c->options.ifconfig_remote_netmask,
			   addr_host (&c->c1.link_socket_addr.local),
			   addr_host (&c->c1.link_socket_addr.remote),
			   !c->options.ifconfig_nowarn,
			   c->c2.es);

  init_tun_post (c->c1.tuntap,
		 &c->c2.frame,
		 &c->options.tuntap_options);

  c->c1.tuntap_owned = true;
}

/*
 * Open tun/tap device, ifconfig, call up script, etc.
 */

static bool
do_open_tun (struct context *c)
{
  struct gc_arena gc = gc_new ();
  bool ret = false;

  c->c2.ipv4_tun = (!c->options.tun_ipv6
		    && is_dev_type (c->options.dev, c->options.dev_type, "tun"));

  if (!c->c1.tuntap)
    {
      /* initialize (but do not open) tun/tap object */
      do_init_tun (c);

      /* allocate route list structure */
      do_alloc_route_list (c);

      /* parse and resolve the route option list */
      if (c->options.routes && c->c1.route_list && c->c2.link_socket)
	do_init_route_list (&c->options, c->c1.route_list, &c->c2.link_socket->info, false, c->c2.es);

      /* do ifconfig */
      if (!c->options.ifconfig_noexec
	  && ifconfig_order () == IFCONFIG_BEFORE_TUN_OPEN)
	{
	  /* guess actual tun/tap unit number that will be returned
	     by open_tun */
	  const char *guess = guess_tuntap_dev (c->options.dev,
						c->options.dev_type,
						c->options.dev_node,
						&gc);
	  do_ifconfig (c->c1.tuntap, guess, TUN_MTU_SIZE (&c->c2.frame), c->c2.es);
	}

      /* open the tun device */
      open_tun (c->options.dev, c->options.dev_type, c->options.dev_node,
		c->options.tun_ipv6, c->c1.tuntap);

      /* do ifconfig */
      if (!c->options.ifconfig_noexec
	  && ifconfig_order () == IFCONFIG_AFTER_TUN_OPEN)
	{
	  do_ifconfig (c->c1.tuntap, c->c1.tuntap->actual_name, TUN_MTU_SIZE (&c->c2.frame), c->c2.es);
	}

      /* run the up script */
      run_up_down (c->options.up_script,
		   c->plugins,
		   OPENVPN_PLUGIN_UP,
		   c->c1.tuntap->actual_name,
		   TUN_MTU_SIZE (&c->c2.frame),
		   EXPANDED_SIZE (&c->c2.frame),
		   print_in_addr_t (c->c1.tuntap->local, IA_EMPTY_IF_UNDEF, &gc),
		   print_in_addr_t (c->c1.tuntap->remote_netmask, IA_EMPTY_IF_UNDEF, &gc),
		   "init",
		   NULL,
		   "up",
		   c->c2.es);

      /* possibly add routes */
      if (!c->options.route_delay_defined)
	do_route (&c->options, c->c1.route_list, c->c1.tuntap, c->plugins, c->c2.es);

      /*
       * Did tun/tap driver give us an MTU?
       */
      if (c->c1.tuntap->post_open_mtu)
	frame_set_mtu_dynamic (&c->c2.frame,
			       c->c1.tuntap->post_open_mtu,
			       SET_MTU_TUN | SET_MTU_UPPER_BOUND);

      ret = true;
    }
  else
    {
      msg (M_INFO, "Preserving previous TUN/TAP instance: %s",
	   c->c1.tuntap->actual_name);

      /* run the up script if user specified --up-restart */
      if (c->options.up_restart)
	run_up_down (c->options.up_script,
		     c->plugins,
		     OPENVPN_PLUGIN_UP,
		     c->c1.tuntap->actual_name,
		     TUN_MTU_SIZE (&c->c2.frame),
		     EXPANDED_SIZE (&c->c2.frame),
		     print_in_addr_t (c->c1.tuntap->local, IA_EMPTY_IF_UNDEF, &gc),
		     print_in_addr_t (c->c1.tuntap->remote_netmask, IA_EMPTY_IF_UNDEF, &gc),
		     "restart",
		     NULL,
		     "up",
		     c->c2.es);
    }
  gc_free (&gc);
  return ret;
}

/*
 * Close TUN/TAP device
 */

static void
do_close_tun_simple (struct context *c)
{
  msg (D_CLOSE, "Closing TUN/TAP interface");
  close_tun (c->c1.tuntap);
  c->c1.tuntap = NULL;
  c->c1.tuntap_owned = false;
#if P2MP
  save_pulled_options_string (c, NULL); /* delete C1-saved pulled_options_string */
#endif
}

static void
do_close_tun (struct context *c, bool force)
{
  struct gc_arena gc = gc_new ();
  if (c->c1.tuntap && c->c1.tuntap_owned)
    {
      const char *tuntap_actual = string_alloc (c->c1.tuntap->actual_name, &gc);
      const in_addr_t local = c->c1.tuntap->local;
      const in_addr_t remote_netmask = c->c1.tuntap->remote_netmask;

      if (force || !(c->sig->signal_received == SIGUSR1 && c->options.persist_tun))
	{
#ifdef ENABLE_MANAGEMENT
	  /* tell management layer we are about to close the TUN/TAP device */
	  if (management)
	    management_pre_tunnel_close (management);
#endif

	  /* delete any routes we added */
	  if (c->c1.route_list)
	    delete_routes (c->c1.route_list, c->c1.tuntap, ROUTE_OPTION_FLAGS (&c->options), c->c2.es);

	  /* actually close tun/tap device based on --down-pre flag */
	  if (!c->options.down_pre)
	    do_close_tun_simple (c);

	  /* Run the down script -- note that it will run at reduced
	     privilege if, for example, "--user nobody" was used. */
	  run_up_down (c->options.down_script,
		       c->plugins,
		       OPENVPN_PLUGIN_DOWN,
		       tuntap_actual,
		       TUN_MTU_SIZE (&c->c2.frame),
		       EXPANDED_SIZE (&c->c2.frame),
		       print_in_addr_t (local, IA_EMPTY_IF_UNDEF, &gc),
		       print_in_addr_t (remote_netmask, IA_EMPTY_IF_UNDEF, &gc),
		       "init",
		       signal_description (c->sig->signal_received,
					   c->sig->signal_text),
		       "down",
		       c->c2.es);

	  /* actually close tun/tap device based on --down-pre flag */
	  if (c->options.down_pre)
	    do_close_tun_simple (c);
	}
      else
	{
	  /* run the down script on this restart if --up-restart was specified */
	  if (c->options.up_restart)
	    run_up_down (c->options.down_script,
			 c->plugins,
			 OPENVPN_PLUGIN_DOWN,
			 tuntap_actual,
			 TUN_MTU_SIZE (&c->c2.frame),
			 EXPANDED_SIZE (&c->c2.frame),
			 print_in_addr_t (local, IA_EMPTY_IF_UNDEF, &gc),
			 print_in_addr_t (remote_netmask, IA_EMPTY_IF_UNDEF, &gc),
			 "restart",
			 signal_description (c->sig->signal_received,
					     c->sig->signal_text),
			 "down",
			 c->c2.es);
	}
    }
  gc_free (&gc);
}

/*
 * Handle delayed tun/tap interface bringup due to --up-delay or --pull
 */

void
do_up (struct context *c, bool pulled_options, unsigned int option_types_found)
{
  if (!c->c2.do_up_ran)
    {
      reset_coarse_timers (c);

      if (pulled_options && option_types_found)
	do_deferred_options (c, option_types_found);

      /* if --up-delay specified, open tun, do ifconfig, and run up script now */
      if (c->options.up_delay || PULL_DEFINED (&c->options))
	{
	  c->c2.did_open_tun = do_open_tun (c);
	  update_time ();

#if P2MP
	  /*
	   * Was tun interface object persisted from previous restart iteration,
	   * and if so did pulled options string change from previous iteration?
	   */
	  if (!c->c2.did_open_tun
	      && PULL_DEFINED (&c->options)
	      && c->c1.tuntap
	      && (!c->c1.pulled_options_string_save || !c->c2.pulled_options_string
		  || strcmp (c->c1.pulled_options_string_save, c->c2.pulled_options_string)))
	    {
	      /* if so, close tun, delete routes, then reinitialize tun and add routes */
	      msg (M_INFO, "NOTE: Pulled options changed on restart, will need to close and reopen TUN/TAP device.");
	      do_close_tun (c, true);
	      openvpn_sleep (1);
	      c->c2.did_open_tun = do_open_tun (c);
	      update_time ();
	    }
#endif
	}

      if (c->c2.did_open_tun)
	{
#if P2MP
	  save_pulled_options_string (c, c->c2.pulled_options_string);
#endif

	  /* if --route-delay was specified, start timer */
	  if (c->options.route_delay_defined)
	    {
	      event_timeout_init (&c->c2.route_wakeup, c->options.route_delay, now);
	      event_timeout_init (&c->c2.route_wakeup_expire, c->options.route_delay + c->options.route_delay_window, now);
	      if (c->c1.tuntap)
		tun_standby_init (c->c1.tuntap);
	    }
	  else
	    {
	      initialization_sequence_completed (c, 0); /* client/p2p --route-delay undefined */
	    }
	}
      else if (c->options.mode == MODE_POINT_TO_POINT)
	{
	  initialization_sequence_completed (c, 0); /* client/p2p restart with --persist-tun */
	}
	
      c->c2.do_up_ran = true;
    }
}

/*
 * These are the option categories which will be accepted by pull.
 */
unsigned int
pull_permission_mask (const struct context *c)
{
  unsigned int flags =
      OPT_P_UP
    | OPT_P_ROUTE_EXTRAS
    | OPT_P_IPWIN32
    | OPT_P_SOCKBUF
    | OPT_P_SOCKFLAGS
    | OPT_P_SETENV
    | OPT_P_SHAPER
    | OPT_P_TIMER
    | OPT_P_COMP
    | OPT_P_PERSIST
    | OPT_P_MESSAGES
    | OPT_P_EXPLICIT_NOTIFY
    | OPT_P_ECHO
    | OPT_P_PULL_MODE;

  if (!c->options.route_nopull)
    flags |= OPT_P_ROUTE;

  return flags;
}

/*
 * Handle non-tun-related pulled options.
 */
void
do_deferred_options (struct context *c, const unsigned int found)
{
  if (found & OPT_P_MESSAGES)
    {
      init_verb_mute (c, IVM_LEVEL_1|IVM_LEVEL_2);
      msg (D_PUSH, "OPTIONS IMPORT: --verb and/or --mute level changed");
    }
  if (found & OPT_P_TIMER)
    {
      do_init_timers (c, true);
      msg (D_PUSH, "OPTIONS IMPORT: timers and/or timeouts modified");
    }

#ifdef ENABLE_OCC
  if (found & OPT_P_EXPLICIT_NOTIFY)
    {
      if (c->options.proto != PROTO_UDPv4 && c->options.explicit_exit_notification)
	{
	  msg (D_PUSH, "OPTIONS IMPORT: --explicit-exit-notify can only be used with --proto udp");
	  c->options.explicit_exit_notification = 0;
	}
      else
	msg (D_PUSH, "OPTIONS IMPORT: explicit notify parm(s) modified");
    }
#endif

#ifdef USE_LZO
  if (found & OPT_P_COMP)
    {
      if (lzo_defined (&c->c2.lzo_compwork))
	{
	  msg (D_PUSH, "OPTIONS IMPORT: LZO parms modified");
	  lzo_modify_flags (&c->c2.lzo_compwork, c->options.lzo);
	}
    }
#endif

  if (found & OPT_P_SHAPER)
    {
      msg (D_PUSH, "OPTIONS IMPORT: traffic shaper enabled");
      do_init_traffic_shaper (c);
    }

  if (found & OPT_P_SOCKBUF)
    {
      msg (D_PUSH, "OPTIONS IMPORT: --sndbuf/--rcvbuf options modified");
      link_socket_update_buffer_sizes (c->c2.link_socket, c->options.rcvbuf, c->options.sndbuf);
    }

  if (found & OPT_P_SOCKFLAGS)
    {
      msg (D_PUSH, "OPTIONS IMPORT: --socket-flags option modified");
      link_socket_update_flags (c->c2.link_socket, c->options.sockflags);
    }

  if (found & OPT_P_PERSIST)
    msg (D_PUSH, "OPTIONS IMPORT: --persist options modified");
  if (found & OPT_P_UP)
    msg (D_PUSH, "OPTIONS IMPORT: --ifconfig/up options modified");
  if (found & OPT_P_ROUTE)
    msg (D_PUSH, "OPTIONS IMPORT: route options modified");
  if (found & OPT_P_ROUTE_EXTRAS)
    msg (D_PUSH, "OPTIONS IMPORT: route-related options modified");
  if (found & OPT_P_IPWIN32)
    msg (D_PUSH, "OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified");
  if (found & OPT_P_SETENV)
    msg (D_PUSH, "OPTIONS IMPORT: environment modified");
}

/*
 * Possible hold on initialization
 */
static bool
do_hold (struct context *c)
{
#ifdef ENABLE_MANAGEMENT
  if (management)
    {
      /* if c is defined, daemonize before hold */
      if (c && c->options.daemon && management_should_daemonize (management))
	do_init_first_time (c);

      /* block until management hold is released */
      if (management_hold (management))
	return true;
    }
#endif
  return false;
}

/*
 * Sleep before restart.
 */
static void
socket_restart_pause (struct context *c)
{
  bool proxy = false;
  int sec = 2;

#ifdef ENABLE_HTTP_PROXY
  if (c->options.http_proxy_options)
    proxy = true;
#endif
#ifdef ENABLE_SOCKS
  if (c->options.socks_proxy_server)
    proxy = true;
#endif

  switch (c->options.proto)
    {
    case PROTO_UDPv4:
      if (proxy)
	sec = c->options.connect_retry_seconds;
      break;
    case PROTO_TCPv4_SERVER:
      sec = 1;
      break;
    case PROTO_TCPv4_CLIENT:
      sec = c->options.connect_retry_seconds;
      break;
    }

#ifdef ENABLE_DEBUG
  if (GREMLIN_CONNECTION_FLOOD_LEVEL (c->options.gremlin))
    sec = 0;
#endif

#if P2MP
  if (auth_retry_get () == AR_NOINTERACT)
    sec = 10;
#endif

  if (c->persist.restart_sleep_seconds > 0 && c->persist.restart_sleep_seconds > sec)
    sec = c->persist.restart_sleep_seconds;
  c->persist.restart_sleep_seconds = 0;

  if (do_hold (NULL))
    sec = 0;

  if (sec)
    {
      msg (D_RESTART, "Restart pause, %d second(s)", sec);
      openvpn_sleep (sec);
    }
}

/*
 * Do a possible pause on context_2 initialization.
 */
static void
do_startup_pause (struct context *c)
{
  if (!c->first_time)
    socket_restart_pause (c);
  else
    do_hold (NULL);
}

/*
 * Finalize MTU parameters based on command line or config file options.
 */
static void
frame_finalize_options (struct context *c, const struct options *o)
{
  if (!o)
    o = &c->options;

  /*
   * Set adjustment factor for buffer alignment when no
   * cipher is used.
   */
  if (!CIPHER_ENABLED (c))
    {
      frame_align_to_extra_frame (&c->c2.frame);
      frame_or_align_flags (&c->c2.frame,
			    FRAME_HEADROOM_MARKER_FRAGMENT
			    |FRAME_HEADROOM_MARKER_READ_LINK
			    |FRAME_HEADROOM_MARKER_READ_STREAM);
    }
  
  frame_finalize (&c->c2.frame,
		  o->link_mtu_defined,
		  o->link_mtu,
		  o->tun_mtu_defined,
		  o->tun_mtu);
}

/*
 * Free a key schedule, including OpenSSL components.
 */
static void
key_schedule_free (struct key_schedule *ks, bool free_ssl_ctx)
{
#ifdef USE_CRYPTO
  free_key_ctx_bi (&ks->static_key);
#ifdef USE_SSL
  if (ks->ssl_ctx && free_ssl_ctx)
    {
      SSL_CTX_free (ks->ssl_ctx);
      free_key_ctx_bi (&ks->tls_auth_key);
    }
#endif /* USE_SSL */
#endif /* USE_CRYPTO */
  CLEAR (*ks);
}

#ifdef USE_CRYPTO

static void
init_crypto_pre (struct context *c, const unsigned int flags)
{
  if (c->options.engine)
    init_crypto_lib_engine (c->options.engine);

  if (flags & CF_LOAD_PERSISTED_PACKET_ID)
    {
      /* load a persisted packet-id for cross-session replay-protection */
      if (c->options.packet_id_file)
	packet_id_persist_load (&c->c1.pid_persist, c->options.packet_id_file);
    }

  /* Initialize crypto options */

  if (c->options.use_iv)
    c->c2.crypto_options.flags |= CO_USE_IV;

  if (c->options.mute_replay_warnings)
    c->c2.crypto_options.flags |= CO_MUTE_REPLAY_WARNINGS;
}

/*
 * Static Key Mode (using a pre-shared key)
 */
static void
do_init_crypto_static (struct context *c, const unsigned int flags)
{
  const struct options *options = &c->options;
  ASSERT (options->shared_secret_file);

  init_crypto_pre (c, flags);

  /* Initialize packet ID tracking */
  if (options->replay)
    {
      packet_id_init (&c->c2.packet_id, options->replay_window,
		      options->replay_time);
      c->c2.crypto_options.packet_id = &c->c2.packet_id;
      c->c2.crypto_options.pid_persist = &c->c1.pid_persist;
      c->c2.crypto_options.flags |= CO_PACKET_ID_LONG_FORM;
      packet_id_persist_load_obj (&c->c1.pid_persist,
				  c->c2.crypto_options.packet_id);
    }

  if (!key_ctx_bi_defined (&c->c1.ks.static_key))
    {
      struct key2 key2;
      struct key_direction_state kds;

      /* Get cipher & hash algorithms */
      init_key_type (&c->c1.ks.key_type, options->ciphername,
		     options->ciphername_defined, options->authname,
		     options->authname_defined, options->keysize,
		     options->test_crypto, true);

      /* Read cipher and hmac keys from shared secret file */
      {
	unsigned int rkf_flags = RKF_MUST_SUCCEED;
	const char *rkf_file = options->shared_secret_file;

#if ENABLE_INLINE_FILES
	if (options->shared_secret_file_inline)
	  {
	    rkf_file = options->shared_secret_file_inline;
	    rkf_flags |= RKF_INLINE;
	  }
#endif
	read_key_file (&key2, rkf_file, rkf_flags);
      }

      /* Check for and fix highly unlikely key problems */
      verify_fix_key2 (&key2, &c->c1.ks.key_type,
		       options->shared_secret_file);

      /* Initialize OpenSSL key objects */
      key_direction_state_init (&kds, options->key_direction);
      must_have_n_keys (options->shared_secret_file, "secret", &key2,
			kds.need_keys);
      init_key_ctx (&c->c1.ks.static_key.encrypt, &key2.keys[kds.out_key],
		    &c->c1.ks.key_type, DO_ENCRYPT, "Static Encrypt");
      init_key_ctx (&c->c1.ks.static_key.decrypt, &key2.keys[kds.in_key],
		    &c->c1.ks.key_type, DO_DECRYPT, "Static Decrypt");

      /* Erase the temporary copy of key */
      CLEAR (key2);
    }
  else
    {
      msg (M_INFO, "Re-using pre-shared static key");
    }

  /* Get key schedule */
  c->c2.crypto_options.key_ctx_bi = &c->c1.ks.static_key;

  /* Compute MTU parameters */
  crypto_adjust_frame_parameters (&c->c2.frame,
				  &c->c1.ks.key_type,
				  options->ciphername_defined,
				  options->use_iv, options->replay, true);

  /* Sanity check on IV, sequence number, and cipher mode options */
  check_replay_iv_consistency (&c->c1.ks.key_type, options->replay,
			       options->use_iv);
}

#ifdef USE_SSL

/*
 * Initialize the persistent component of OpenVPN's TLS mode,
 * which is preserved across SIGUSR1 resets.
 */
static void
do_init_crypto_tls_c1 (struct context *c)
{
  const struct options *options = &c->options;

  if (!c->c1.ks.ssl_ctx)
    {
      /*
       * Initialize the OpenSSL library's global
       * SSL context.
       */
      c->c1.ks.ssl_ctx = init_ssl (options);
      if (!c->c1.ks.ssl_ctx)
	{
#if P2MP
	  switch (auth_retry_get ())
	    {
	    case AR_NONE:
	      msg (M_FATAL, "Error: private key password verification failed");
	      break;
	    case AR_INTERACT:
	      ssl_purge_auth ();
	    case AR_NOINTERACT:
	      c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- Password failure error */
	      break;
	    default:
	      ASSERT (0);
	    }
	  c->sig->signal_text = "private-key-password-failure";
	  return;
#else
	  msg (M_FATAL, "Error: private key password verification failed");
#endif
	}

      /* Get cipher & hash algorithms */
      init_key_type (&c->c1.ks.key_type, options->ciphername,
		     options->ciphername_defined, options->authname,
		     options->authname_defined, options->keysize, true, true);

      /* TLS handshake authentication (--tls-auth) */
      if (options->tls_auth_file)
	{
	  unsigned int flags = 0;
	  const char *file = options->tls_auth_file;

#if ENABLE_INLINE_FILES
	  if (options->tls_auth_file_inline)
	    {
	      flags |= GHK_INLINE;
	      file = options->tls_auth_file_inline;
	    }
#endif
	  get_tls_handshake_key (&c->c1.ks.key_type,
				 &c->c1.ks.tls_auth_key,
				 file,
				 options->key_direction,
				 flags);
	}

#if ENABLE_INLINE_FILES
      if (options->priv_key_file_inline)
	{
	  string_clear (c->options.priv_key_file_inline);
	  c->options.priv_key_file_inline = NULL;
	}
#endif
    }
  else
    {
      msg (M_INFO, "Re-using SSL/TLS context");
    }
}

static void
do_init_crypto_tls (struct context *c, const unsigned int flags)
{
  const struct options *options = &c->options;
  struct tls_options to;
  bool packet_id_long_form;

  ASSERT (options->tls_server || options->tls_client);
  ASSERT (!options->test_crypto);

  init_crypto_pre (c, flags);

  /* Make sure we are either a TLS client or server but not both */
  ASSERT (options->tls_server == !options->tls_client);

  /* initialize persistent component */
  do_init_crypto_tls_c1 (c);
  if (IS_SIG (c))
    return;

  /* Sanity check on IV, sequence number, and cipher mode options */
  check_replay_iv_consistency (&c->c1.ks.key_type, options->replay,
			       options->use_iv);

  /* In short form, unique datagram identifier is 32 bits, in long form 64 bits */
  packet_id_long_form = cfb_ofb_mode (&c->c1.ks.key_type);

  /* Compute MTU parameters */
  crypto_adjust_frame_parameters (&c->c2.frame,
				  &c->c1.ks.key_type,
				  options->ciphername_defined,
				  options->use_iv,
				  options->replay, packet_id_long_form);
  tls_adjust_frame_parameters (&c->c2.frame);

  /* Set all command-line TLS-related options */
  CLEAR (to);

  to.crypto_flags_and = ~(CO_PACKET_ID_LONG_FORM);
  if (packet_id_long_form)
    to.crypto_flags_or = CO_PACKET_ID_LONG_FORM;

  to.ssl_ctx = c->c1.ks.ssl_ctx;
  to.key_type = c->c1.ks.key_type;
  to.server = options->tls_server;
  to.key_method = options->key_method;
  to.replay = options->replay;
  to.replay_window = options->replay_window;
  to.replay_time = options->replay_time;
  to.transition_window = options->transition_window;
  to.handshake_window = options->handshake_window;
  to.packet_timeout = options->tls_timeout;
  to.renegotiate_bytes = options->renegotiate_bytes;
  to.renegotiate_packets = options->renegotiate_packets;
  to.renegotiate_seconds = options->renegotiate_seconds;
  to.single_session = options->single_session;

  /* should we not xmit any packets until we get an initial
     response from client? */
  if (to.server && options->proto == PROTO_TCPv4_SERVER)
    to.xmit_hold = true;

#ifdef ENABLE_OCC
  to.disable_occ = !options->occ;
#endif

  to.verify_command = options->tls_verify;
  to.verify_x509name = options->tls_remote;
  to.crl_file = options->crl_file;
  to.ns_cert_type = options->ns_cert_type;
  memmove (to.remote_cert_ku, options->remote_cert_ku, sizeof (to.remote_cert_ku));
  to.remote_cert_eku = options->remote_cert_eku;
  to.es = c->c2.es;

#ifdef ENABLE_DEBUG
  to.gremlin = c->options.gremlin;
#endif

  to.plugins = c->plugins;

#if P2MP_SERVER
  to.auth_user_pass_verify_script = options->auth_user_pass_verify_script;
  to.auth_user_pass_verify_script_via_file = options->auth_user_pass_verify_script_via_file;
  to.tmp_dir = options->tmp_dir;
  to.username_as_common_name = options->username_as_common_name;
  if (options->ccd_exclusive)
    to.client_config_dir_exclusive = options->client_config_dir;
#endif

  /* TLS handshake authentication (--tls-auth) */
  if (options->tls_auth_file)
    {
      to.tls_auth_key = c->c1.ks.tls_auth_key;
      to.tls_auth.pid_persist = &c->c1.pid_persist;
      to.tls_auth.flags |= CO_PACKET_ID_LONG_FORM;
      crypto_adjust_frame_parameters (&to.frame,
				      &c->c1.ks.key_type,
				      false, false, true, true);
    }

  /* If we are running over TCP, allow for
     length prefix */
  socket_adjust_frame_parameters (&to.frame, options->proto);

  /*
   * Initialize OpenVPN's master TLS-mode object.
   */
  if (flags & CF_INIT_TLS_MULTI)
    c->c2.tls_multi = tls_multi_init (&to);

  if (flags & CF_INIT_TLS_AUTH_STANDALONE)
    c->c2.tls_auth_standalone = tls_auth_standalone_init (&to, &c->c2.gc);
}

static void
do_init_finalize_tls_frame (struct context *c)
{
  if (c->c2.tls_multi)
    {
      tls_multi_init_finalize (c->c2.tls_multi, &c->c2.frame);
      ASSERT (EXPANDED_SIZE (&c->c2.tls_multi->opt.frame) <=
	      EXPANDED_SIZE (&c->c2.frame));
      frame_print (&c->c2.tls_multi->opt.frame, D_MTU_INFO,
		   "Control Channel MTU parms");
    }
  if (c->c2.tls_auth_standalone)
    {
      tls_auth_standalone_finalize (c->c2.tls_auth_standalone, &c->c2.frame);
      frame_print (&c->c2.tls_auth_standalone->frame, D_MTU_INFO,
		   "TLS-Auth MTU parms");
    }
}

#endif /* USE_SSL */
#endif /* USE_CRYPTO */

#ifdef USE_CRYPTO
/*
 * No encryption or authentication.
 */
static void
do_init_crypto_none (const struct context *c)
{
  ASSERT (!c->options.test_crypto);
  msg (M_WARN,
       "******* WARNING *******: all encryption and authentication features disabled -- all data will be tunnelled as cleartext");
}
#endif

static void
do_init_crypto (struct context *c, const unsigned int flags)
{
#ifdef USE_CRYPTO
  if (c->options.shared_secret_file)
    do_init_crypto_static (c, flags);
#ifdef USE_SSL
  else if (c->options.tls_server || c->options.tls_client)
    do_init_crypto_tls (c, flags);
#endif
  else				/* no encryption or authentication. */
    do_init_crypto_none (c);
#else /* USE_CRYPTO */
  msg (M_WARN,
       "******* WARNING *******: " PACKAGE_NAME
       " built without OpenSSL -- encryption and authentication features disabled -- all data will be tunnelled as cleartext");
#endif /* USE_CRYPTO */
}

static void
do_init_frame (struct context *c)
{
#ifdef USE_LZO
  /*
   * Initialize LZO compression library.
   */
  if (c->options.lzo & LZO_SELECTED)
    {
      lzo_adjust_frame_parameters (&c->c2.frame);

      /*
       * LZO usage affects buffer alignment.
       */
      if (CIPHER_ENABLED (c))
	{
	  frame_add_to_align_adjust (&c->c2.frame, LZO_PREFIX_LEN);
	  frame_or_align_flags (&c->c2.frame,
				FRAME_HEADROOM_MARKER_FRAGMENT
				|FRAME_HEADROOM_MARKER_DECRYPT);
	}

#ifdef ENABLE_FRAGMENT
      lzo_adjust_frame_parameters (&c->c2.frame_fragment_omit);	/* omit LZO frame delta from final frame_fragment */
#endif
    }
#endif /* USE_LZO */

#ifdef ENABLE_SOCKS
  /*
   * Adjust frame size for UDP Socks support.
   */
  if (c->options.socks_proxy_server)
    socks_adjust_frame_parameters (&c->c2.frame, c->options.proto);
#endif

  /*
   * Adjust frame size based on the --tun-mtu-extra parameter.
   */
  if (c->options.tun_mtu_extra_defined)
    tun_adjust_frame_parameters (&c->c2.frame, c->options.tun_mtu_extra);

  /*
   * Adjust frame size based on link socket parameters.
   * (Since TCP is a stream protocol, we need to insert
   * a packet length uint16_t in the buffer.)
   */
  socket_adjust_frame_parameters (&c->c2.frame, c->options.proto);

  /*
   * Fill in the blanks in the frame parameters structure,
   * make sure values are rational, etc.
   */
  frame_finalize_options (c, NULL);

#ifdef ENABLE_FRAGMENT
  /*
   * Set frame parameter for fragment code.  This is necessary because
   * the fragmentation code deals with payloads which have already been
   * passed through the compression code.
   */
  c->c2.frame_fragment = c->c2.frame;
  frame_subtract_extra (&c->c2.frame_fragment, &c->c2.frame_fragment_omit);
#endif

#if defined(ENABLE_FRAGMENT) && defined(ENABLE_OCC)
  /*
   * MTU advisories
   */
  if (c->options.fragment && c->options.mtu_test)
    msg (M_WARN,
	 "WARNING: using --fragment and --mtu-test together may produce an inaccurate MTU test result");
#endif

#ifdef ENABLE_FRAGMENT
  if ((c->options.mssfix || c->options.fragment)
      && TUN_MTU_SIZE (&c->c2.frame_fragment) != ETHERNET_MTU)
    msg (M_WARN,
	 "WARNING: normally if you use --mssfix and/or --fragment, you should also set --tun-mtu %d (currently it is %d)",
	 ETHERNET_MTU, TUN_MTU_SIZE (&c->c2.frame_fragment));
#endif
}

static void
do_option_warnings (struct context *c)
{
  const struct options *o = &c->options;

#if 1 /* JYFIXME -- port warning */
  if (!o->port_option_used && (o->local_port == OPENVPN_PORT && o->remote_port == OPENVPN_PORT))
    msg (M_WARN, "IMPORTANT: OpenVPN's default port number is now %d, based on an official port number assignment by IANA.  OpenVPN 2.0-beta16 and earlier used 5000 as the default port.",
	 OPENVPN_PORT);
#endif

  if (o->ping_send_timeout && !o->ping_rec_timeout)
    msg (M_WARN, "WARNING: --ping should normally be used with --ping-restart or --ping-exit");

  if (o->username || o->groupname || o->chroot_dir)
   {
    if (!o->persist_tun)
     msg (M_WARN, "WARNING: you are using user/group/chroot without persist-tun -- this may cause restarts to fail");
    if (!o->persist_key
#ifdef ENABLE_PKCS11
	&& !o->pkcs11_id
#endif
	)
     msg (M_WARN, "WARNING: you are using user/group/chroot without persist-key -- this may cause restarts to fail");
   }

#if P2MP
  if (o->pull && o->ifconfig_local && c->first_time)
    msg (M_WARN, "WARNING: using --pull/--client and --ifconfig together is probably not what you want");

#if P2MP_SERVER
  if (o->mode == MODE_SERVER)
    {
      if (o->duplicate_cn && o->client_config_dir)
	msg (M_WARN, "WARNING: using --duplicate-cn and --client-config-dir together is probably not what you want");
      if (o->duplicate_cn && o->ifconfig_pool_persist_filename)
	msg (M_WARN, "WARNING: --ifconfig-pool-persist will not work with --duplicate-cn");
      if (!o->keepalive_ping || !o->keepalive_timeout)
	msg (M_WARN, "WARNING: --keepalive option is missing from server config");
    }
#endif
#endif

#ifdef USE_CRYPTO
  if (!o->replay)
    msg (M_WARN, "WARNING: You have disabled Replay Protection (--no-replay) which may make " PACKAGE_NAME " less secure");
  if (!o->use_iv)
    msg (M_WARN, "WARNING: You have disabled Crypto IVs (--no-iv) which may make " PACKAGE_NAME " less secure");

#ifdef USE_SSL
  if (o->tls_client
      && !o->tls_verify
      && !o->tls_remote
      && !(o->ns_cert_type & NS_SSL_SERVER)
      && (o->remote_cert_eku == NULL || !o->remote_cert_eku[0]))
    msg (M_WARN, "WARNING: No server certificate verification method has been enabled.  See http://openvpn.net/howto.html#mitm for more info.");
#endif
#endif

#ifndef CONNECT_NONBLOCK
  if (o->connect_timeout_defined)
    msg (M_WARN, "NOTE: --connect-timeout option is not supported on this OS");
#endif
}

static void
do_init_frame_tls (struct context *c)
{
#if defined(USE_CRYPTO) && defined(USE_SSL)
  do_init_finalize_tls_frame (c);
#endif
}

struct context_buffers *
init_context_buffers (const struct frame *frame)
{
  struct context_buffers *b;

  ALLOC_OBJ_CLEAR (b, struct context_buffers);

  b->read_link_buf = alloc_buf (BUF_SIZE (frame));
  b->read_tun_buf = alloc_buf (BUF_SIZE (frame));

  b->aux_buf = alloc_buf (BUF_SIZE (frame));

#ifdef USE_CRYPTO
  b->encrypt_buf = alloc_buf (BUF_SIZE (frame));
  b->decrypt_buf = alloc_buf (BUF_SIZE (frame));
#endif

#ifdef USE_LZO
  b->lzo_compress_buf = alloc_buf (BUF_SIZE (frame));
  b->lzo_decompress_buf = alloc_buf (BUF_SIZE (frame));
#endif

  return b;
}

void
free_context_buffers (struct context_buffers *b)
{
  if (b)
    {
      free_buf (&b->read_link_buf);
      free_buf (&b->read_tun_buf);
      free_buf (&b->aux_buf);

#ifdef USE_LZO
      free_buf (&b->lzo_compress_buf);
      free_buf (&b->lzo_decompress_buf);
#endif

#ifdef USE_CRYPTO
      free_buf (&b->encrypt_buf);
      free_buf (&b->decrypt_buf);
#endif

      free (b);
    }
}

/*
 * Now that we know all frame parameters, initialize
 * our buffers.
 */
static void
do_init_buffers (struct context *c)
{
  c->c2.buffers = init_context_buffers (&c->c2.frame);
  c->c2.buffers_owned = true;
}

#ifdef ENABLE_FRAGMENT
/*
 * Fragmenting code has buffers to initialize
 * once frame parameters are known.
 */
static void
do_init_fragment (struct context *c)
{
  ASSERT (c->options.fragment);
  frame_set_mtu_dynamic (&c->c2.frame_fragment,
			 c->options.fragment, SET_MTU_UPPER_BOUND);
  fragment_frame_init (c->c2.fragment, &c->c2.frame_fragment);
}
#endif

/*
 * Set the --mssfix option.
 */
static void
do_init_mssfix (struct context *c)
{
  if (c->options.mssfix)
    {
      frame_set_mtu_dynamic (&c->c2.frame,
			     c->options.mssfix, SET_MTU_UPPER_BOUND);
    }
}

/*
 * Allocate our socket object.
 */
static void
do_link_socket_new (struct context *c)
{
  ASSERT (!c->c2.link_socket);
  c->c2.link_socket = link_socket_new ();
  c->c2.link_socket_owned = true;
}

/*
 * bind the TCP/UDP socket
 */
static void
do_init_socket_1 (struct context *c, int mode)
{
  link_socket_init_phase1 (c->c2.link_socket,
			   c->options.local,
			   c->c1.remote_list,
			   c->options.local_port,
			   c->options.proto,
			   mode,
			   c->c2.accept_from,
#ifdef ENABLE_HTTP_PROXY
			   c->c1.http_proxy,
#endif
#ifdef ENABLE_SOCKS
			   c->c1.socks_proxy,
#endif
#ifdef ENABLE_DEBUG
			   c->options.gremlin,
#endif
			   c->options.bind_local,
			   c->options.remote_float,
			   c->options.inetd,
			   &c->c1.link_socket_addr,
			   c->options.ipchange,
			   c->plugins,
			   c->options.resolve_retry_seconds,
			   c->options.connect_retry_seconds,
			   c->options.connect_timeout,
			   c->options.connect_retry_max,
			   c->options.mtu_discover_type,
			   c->options.rcvbuf,
			   c->options.sndbuf,
			   c->options.sockflags);
}

/*
 * finalize the TCP/UDP socket
 */
static void
do_init_socket_2 (struct context *c)
{
  link_socket_init_phase2 (c->c2.link_socket, &c->c2.frame,
			   &c->sig->signal_received);
}

/*
 * Print MTU INFO
 */
static void
do_print_data_channel_mtu_parms (struct context *c)
{
  frame_print (&c->c2.frame, D_MTU_INFO, "Data Channel MTU parms");
#ifdef ENABLE_FRAGMENT
  if (c->c2.fragment)
    frame_print (&c->c2.frame_fragment, D_MTU_INFO,
		 "Fragmentation MTU parms");
#endif
}

#ifdef ENABLE_OCC
/*
 * Get local and remote options compatibility strings.
 */
static void
do_compute_occ_strings (struct context *c)
{
  struct gc_arena gc = gc_new ();

  c->c2.options_string_local =
    options_string (&c->options, &c->c2.frame, c->c1.tuntap, false, &gc);
  c->c2.options_string_remote =
    options_string (&c->options, &c->c2.frame, c->c1.tuntap, true, &gc);

  msg (D_SHOW_OCC, "Local Options String: '%s'", c->c2.options_string_local);
  msg (D_SHOW_OCC, "Expected Remote Options String: '%s'",
       c->c2.options_string_remote);

#ifdef USE_CRYPTO
  msg (D_SHOW_OCC_HASH, "Local Options hash (VER=%s): '%s'",
       options_string_version (c->c2.options_string_local, &gc),
       md5sum ((uint8_t*)c->c2.options_string_local,
	       strlen (c->c2.options_string_local), 9, &gc));
  msg (D_SHOW_OCC_HASH, "Expected Remote Options hash (VER=%s): '%s'",
       options_string_version (c->c2.options_string_remote, &gc),
       md5sum ((uint8_t*)c->c2.options_string_remote,
	       strlen (c->c2.options_string_remote), 9, &gc));
#endif

#if defined(USE_CRYPTO) && defined(USE_SSL)
  if (c->c2.tls_multi)
    tls_multi_init_set_options (c->c2.tls_multi,
				c->c2.options_string_local,
				c->c2.options_string_remote);
#endif

  gc_free (&gc);
}
#endif

/*
 * These things can only be executed once per program instantiation.
 * Set up for possible UID/GID downgrade, but don't do it yet.
 * Daemonize if requested.
 */
static void
do_init_first_time (struct context *c)
{
  if (c->first_time && !c->did_we_daemonize && !c->c0)
    {
      struct context_0 *c0;

      ALLOC_OBJ_CLEAR_GC (c->c0, struct context_0, &c->gc);
      c0 = c->c0;
      
      /* get user and/or group that we want to setuid/setgid to */
      c0->uid_gid_specified =
	get_group (c->options.groupname, &c0->group_state) |
	get_user (c->options.username, &c0->user_state);

      /* get --writepid file descriptor */
      get_pid_file (c->options.writepid, &c0->pid_state);

      /* become a daemon if --daemon */
      c->did_we_daemonize = possibly_become_daemon (&c->options, c->first_time);

      /* should we disable paging? */
      if (c->options.mlock && c->did_we_daemonize)
	do_mlockall (true);	/* call again in case we daemonized */

      /* save process ID in a file */
      write_pid (&c0->pid_state);

      /* should we change scheduling priority? */
      set_nice (c->options.nice);
    }
}

/*
 * If xinetd/inetd mode, don't allow restart.
 */
static void
do_close_check_if_restart_permitted (struct context *c)
{
  if (c->options.inetd
      && (c->sig->signal_received == SIGHUP
	  || c->sig->signal_received == SIGUSR1))
    {
      c->sig->signal_received = SIGTERM;
      msg (M_INFO,
	   PACKAGE_NAME
	   " started by inetd/xinetd cannot restart... Exiting.");
    }
}

/*
 * free buffers
 */
static void
do_close_free_buf (struct context *c)
{
  if (c->c2.buffers_owned)
    {
      free_context_buffers (c->c2.buffers);
      c->c2.buffers = NULL;
      c->c2.buffers_owned = false;
    }
}

/*
 * close TLS
 */
static void
do_close_tls (struct context *c)
{
#if defined(USE_CRYPTO) && defined(USE_SSL)
  if (c->c2.tls_multi)
    {
      tls_multi_free (c->c2.tls_multi, true);
      c->c2.tls_multi = NULL;
    }

#ifdef ENABLE_OCC
  /* free options compatibility strings */
  if (c->c2.options_string_local)
    free (c->c2.options_string_local);
  if (c->c2.options_string_remote)
    free (c->c2.options_string_remote);
  c->c2.options_string_local = c->c2.options_string_remote = NULL;
#endif
#endif
}

/*
 * Free key schedules
 */
static void
do_close_free_key_schedule (struct context *c, bool free_ssl_ctx)
{
  if (!(c->sig->signal_received == SIGUSR1 && c->options.persist_key))
    key_schedule_free (&c->c1.ks, free_ssl_ctx);
}

/*
 * Close TCP/UDP connection
 */
static void
do_close_link_socket (struct context *c)
{
  if (c->c2.link_socket && c->c2.link_socket_owned)
    {
      link_socket_close (c->c2.link_socket);
      c->c2.link_socket = NULL;
    }

  if (!(c->sig->signal_received == SIGUSR1 && c->options.persist_remote_ip))
    {
      CLEAR (c->c1.link_socket_addr.remote);
      CLEAR (c->c1.link_socket_addr.actual);
    }

  if (!(c->sig->signal_received == SIGUSR1 && c->options.persist_local_ip))
    CLEAR (c->c1.link_socket_addr.local);
}

/*
 * Close packet-id persistance file
 */
static void
do_close_packet_id (struct context *c)
{
#ifdef USE_CRYPTO
  packet_id_free (&c->c2.packet_id);
  packet_id_persist_save (&c->c1.pid_persist);
  if (!(c->sig->signal_received == SIGUSR1))
    packet_id_persist_close (&c->c1.pid_persist);
#endif
}

#ifdef ENABLE_FRAGMENT
/*
 * Close fragmentation handler.
 */
static void
do_close_fragment (struct context *c)
{
  if (c->c2.fragment)
    {
      fragment_free (c->c2.fragment);
      c->c2.fragment = NULL;
    }
}
#endif

/*
 * Open and close our event objects.
 */

static void
do_event_set_init (struct context *c,
		   bool need_us_timeout)
{
  unsigned int flags = 0;

  c->c2.event_set_max = BASE_N_EVENTS;

  flags |= EVENT_METHOD_FAST;

  if (need_us_timeout)
    flags |= EVENT_METHOD_US_TIMEOUT;

  c->c2.event_set = event_set_init (&c->c2.event_set_max, flags);
  c->c2.event_set_owned = true;
}

static void
do_close_event_set (struct context *c)
{
  if (c->c2.event_set && c->c2.event_set_owned)
    {
      event_free (c->c2.event_set);
      c->c2.event_set = NULL;
      c->c2.event_set_owned = false;
    }
}

/*
 * Open and close --status file
 */

static void
do_open_status_output (struct context *c)
{
  if (!c->c1.status_output)
    {
      c->c1.status_output = status_open (c->options.status_file,
					 c->options.status_file_update_freq,
					 -1,
					 NULL,
					 STATUS_OUTPUT_WRITE);
      c->c1.status_output_owned = true;
    }
}

static void
do_close_status_output (struct context *c)
{
  if (!(c->sig->signal_received == SIGUSR1))
    {
      if (c->c1.status_output_owned && c->c1.status_output)
	{
	  status_close (c->c1.status_output);
	  c->c1.status_output = NULL;
	  c->c1.status_output_owned = false;
	}
    }
}

/*
 * Handle ifconfig-pool persistance object.
 */
static void
do_open_ifconfig_pool_persist (struct context *c)
{
#if P2MP_SERVER
  if (!c->c1.ifconfig_pool_persist && c->options.ifconfig_pool_persist_filename)
    {
      c->c1.ifconfig_pool_persist = ifconfig_pool_persist_init (c->options.ifconfig_pool_persist_filename,
								c->options.ifconfig_pool_persist_refresh_freq);
      c->c1.ifconfig_pool_persist_owned = true;
    }
#endif
}

static void
do_close_ifconfig_pool_persist (struct context *c)
{
#if P2MP_SERVER
  if (!(c->sig->signal_received == SIGUSR1))
    {
      if (c->c1.ifconfig_pool_persist && c->c1.ifconfig_pool_persist_owned)
	{
	  ifconfig_pool_persist_close (c->c1.ifconfig_pool_persist);
	  c->c1.ifconfig_pool_persist = NULL;
	  c->c1.ifconfig_pool_persist_owned = false;
	}
    }
#endif
}

/*
 * Inherit environmental variables
 */

static void
do_inherit_env (struct context *c, const struct env_set *src)
{
  c->c2.es = env_set_create (&c->c2.gc);
  env_set_inherit (c->c2.es, src);
}

/*
 * Fast I/O setup.  Fast I/O is an optimization which only works
 * if all of the following are true:
 *
 * (1) The platform is not Windows
 * (2) --proto udp is enabled
 * (3) --shaper is disabled
 */
static void
do_setup_fast_io (struct context *c)
{
  if (c->options.fast_io)
    {
#ifdef WIN32
      msg (M_INFO, "NOTE: --fast-io is disabled since we are running on Windows");
#else
      if (c->options.proto != PROTO_UDPv4)
	msg (M_INFO, "NOTE: --fast-io is disabled since we are not using UDP");
      else
	{
#ifdef HAVE_GETTIMEOFDAY
	  if (c->options.shaper)
	    msg (M_INFO, "NOTE: --fast-io is disabled since we are using --shaper");
	  else
#endif
	    {
	      c->c2.fast_io = true;
	    }
	}
#endif
    }
}

static void
do_signal_on_tls_errors (struct context *c)
{
#if defined(USE_CRYPTO) && defined(USE_SSL)
  if (c->options.tls_exit)
    c->c2.tls_exit_signal = SIGTERM;
  else
    c->c2.tls_exit_signal = SIGUSR1;    
#endif
}

#ifdef ENABLE_PLUGIN

void
init_plugins (struct context *c)
{
  if (c->options.plugin_list && !c->plugins)
    {
      c->plugins = plugin_list_init (c->options.plugin_list);
      c->plugins_owned = true;
    }
}

void
open_plugins (struct context *c, const bool import_options, int init_point)
{
  if (c->plugins && c->plugins_owned)
    {
      if (import_options)
	{
	  struct plugin_return pr, config;
	  plugin_return_init (&pr);
	  plugin_list_open (c->plugins, c->options.plugin_list, &pr, c->c2.es, init_point);
	  plugin_return_get_column (&pr, &config, "config");
	  if (plugin_return_defined (&config))
	    {
	      int i;
	      for (i = 0; i < config.n; ++i)
		{
		  unsigned int option_types_found = 0;
		  if (config.list[i] && config.list[i]->value)
		    options_plugin_import (&c->options,
					   config.list[i]->value,
					   D_IMPORT_ERRORS|M_OPTERR,
					   OPT_P_DEFAULT & ~OPT_P_PLUGIN,
					   &option_types_found,
					   c->es);
		}
	    }
	  plugin_return_free (&pr);
	}
      else
	{
	  plugin_list_open (c->plugins, c->options.plugin_list, NULL, c->c2.es, init_point);
	}
    }
}

static void
do_close_plugins (struct context *c)
{
  if (c->plugins && c->plugins_owned && !(c->sig->signal_received == SIGUSR1))
    {
      plugin_list_close (c->plugins);
      c->plugins = NULL;
      c->plugins_owned = false;
    }
}

static void
do_inherit_plugins (struct context *c, const struct context *src)
{
  if (!c->plugins && src->plugins)
    {
      c->plugins = plugin_list_inherit (src->plugins);
      c->plugins_owned = true;
    }
}

#endif

#ifdef ENABLE_MANAGEMENT

static void
management_callback_status_p2p (void *arg, const int version, struct status_output *so)
{
  struct context *c = (struct context *) arg;
  print_status (c, so);
}

void
management_show_net_callback (void *arg, const int msglevel)
{
#ifdef WIN32
  show_routes (msglevel);
  show_adapters (msglevel);
  msg (msglevel, "END");
#else
  msg (msglevel, "ERROR: Sorry, this command is currently only implemented on Windows");
#endif
}

#endif

void
init_management_callback_p2p (struct context *c)
{
#ifdef ENABLE_MANAGEMENT
  if (management)
    {
      struct management_callback cb;
      CLEAR (cb);
      cb.arg = c;
      cb.status = management_callback_status_p2p;
      cb.show_net = management_show_net_callback;
      management_set_callback (management, &cb);
    }
#endif
}

#ifdef ENABLE_MANAGEMENT

void
init_management (struct context *c)
{
  if (!management)
    management = management_init ();
}

bool
open_management (struct context *c)
{
  /* initialize management layer */
  if (management)
    {
      if (c->options.management_addr)
	{
	  if (management_open (management,
			       c->options.management_addr,
			       c->options.management_port,
			       c->options.management_user_pass,
			       c->options.mode == MODE_SERVER,
			       c->options.management_query_passwords,
			       c->options.management_log_history_cache,
			       c->options.management_echo_buffer_size,
			       c->options.management_state_buffer_size,
			       c->options.management_hold,
			       c->options.management_client,
			       c->options.management_write_peer_info_file))
	    {
	      management_set_state (management,
				    OPENVPN_STATE_CONNECTING,
				    NULL,
				    (in_addr_t)0,
				    (in_addr_t)0);
	    }

	  /* possible wait */
	  do_hold (c);
	  if (IS_SIG (c))
	    {
	      msg (M_WARN, "Signal received from management interface, exiting");
	      return false;
	    }
	}
      else
	close_management ();
    }
  return true;
}

void
close_management (void)
{
  if (management)
    {
      management_close (management);
      management = NULL;
    }
}

#endif


void
uninit_management_callback (void)
{
#ifdef ENABLE_MANAGEMENT
  if (management)
    {
      management_clear_callback (management);
    }
#endif
}

/*
 * Initialize a tunnel instance, handle pre and post-init
 * signal settings.
 */
void
init_instance_handle_signals (struct context *c, const struct env_set *env, const unsigned int flags)
{
  pre_init_signal_catch ();
  init_instance (c, env, flags);
  post_init_signal_catch ();

  /*
   * This is done so that signals thrown during
   * initialization can bring us back to
   * a management hold.
   */
  if (IS_SIG (c))
    {
      remap_signal (c);
      uninit_management_callback ();  
    }
}

/*
 * Initialize a tunnel instance.
 */
void
init_instance (struct context *c, const struct env_set *env, const unsigned int flags)
{
  const struct options *options = &c->options;
  const bool child = (c->mode == CM_CHILD_TCP || c->mode == CM_CHILD_UDP);
  int link_socket_mode = LS_MODE_DEFAULT;

  /* init garbage collection level */
  gc_init (&c->c2.gc);

  /* signals caught here will abort */
  c->sig->signal_received = 0;
  c->sig->signal_text = NULL;
  c->sig->hard = false;

  /* link_socket_mode allows CM_CHILD_TCP
     instances to inherit acceptable fds
     from a top-level parent */
  if (c->options.proto == PROTO_TCPv4_SERVER)
    {
      if (c->mode == CM_TOP)
	link_socket_mode = LS_MODE_TCP_LISTEN;
      else if (c->mode == CM_CHILD_TCP)
	link_socket_mode = LS_MODE_TCP_ACCEPT_FROM;
    }

  /* should we disable paging? */
  if (c->first_time && options->mlock)
    do_mlockall (true);

  /* possible sleep or management hold if restart */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    {
      do_startup_pause (c);
      if (IS_SIG (c))
	goto sig;
    }

#if P2MP
  /* get passwords if undefined */
  if (auth_retry_get () == AR_INTERACT)
    init_query_passwords (c);
#endif

  /* initialize context level 2 --verb/--mute parms */
  init_verb_mute (c, IVM_LEVEL_2);

  /* set error message delay for non-server modes */
  if (c->mode == CM_P2P)
    set_check_status_error_delay (P2P_ERROR_DELAY_MS);
    
  /* warn about inconsistent options */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    do_option_warnings (c);

  /* inherit environmental variables */
  if (env)
    do_inherit_env (c, env);

#ifdef ENABLE_PLUGIN
  /* initialize plugins */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    open_plugins (c, false, OPENVPN_PLUGIN_INIT_PRE_DAEMON);
#endif

  /* should we enable fast I/O? */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    do_setup_fast_io (c);

  /* should we throw a signal on TLS errors? */
  do_signal_on_tls_errors (c);

  /* open --status file */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    do_open_status_output (c);

  /* open --ifconfig-pool-persist file */
  if (c->mode == CM_TOP)
    do_open_ifconfig_pool_persist (c);

#ifdef ENABLE_OCC
  /* reset OCC state */
  if (c->mode == CM_P2P || child)
    c->c2.occ_op = occ_reset_op ();
#endif

  /* our wait-for-i/o objects, different for posix vs. win32 */
  if (c->mode == CM_P2P)
    do_event_set_init (c, SHAPER_DEFINED (&c->options));
  else if (c->mode == CM_CHILD_TCP)
    do_event_set_init (c, false);

  /* allocate our socket object */
  if (c->mode == CM_P2P || c->mode == CM_TOP || c->mode == CM_CHILD_TCP)
    do_link_socket_new (c);

#ifdef ENABLE_FRAGMENT
  /* initialize internal fragmentation object */
  if (options->fragment && (c->mode == CM_P2P || child))
    c->c2.fragment = fragment_init (&c->c2.frame);
#endif

  /* init crypto layer */
  {
    unsigned int crypto_flags = 0;
    if (c->mode == CM_TOP)
      crypto_flags = CF_INIT_TLS_AUTH_STANDALONE;
    else if (c->mode == CM_P2P)
      crypto_flags = CF_LOAD_PERSISTED_PACKET_ID | CF_INIT_TLS_MULTI;
    else if (child)
      crypto_flags = CF_INIT_TLS_MULTI;
    do_init_crypto (c, crypto_flags);
    if (IS_SIG (c) && !child)
      goto sig;
  }

#ifdef USE_LZO
  /* initialize LZO compression library. */
  if ((options->lzo & LZO_SELECTED) && (c->mode == CM_P2P || child))
    lzo_compress_init (&c->c2.lzo_compwork, options->lzo);
#endif

  /* initialize MTU variables */
  do_init_frame (c);

  /* initialize TLS MTU variables */
  do_init_frame_tls (c);

  /* init workspace buffers whose size is derived from frame size */
  if (c->mode == CM_P2P || c->mode == CM_CHILD_TCP)
    do_init_buffers (c);

#ifdef ENABLE_FRAGMENT
  /* initialize internal fragmentation capability with known frame size */
  if (options->fragment && (c->mode == CM_P2P || child))
    do_init_fragment (c);
#endif

  /* initialize dynamic MTU variable */
  do_init_mssfix (c);

  /* bind the TCP/UDP socket */
  if (c->mode == CM_P2P || c->mode == CM_TOP || c->mode == CM_CHILD_TCP)
    do_init_socket_1 (c, link_socket_mode);

  /* initialize tun/tap device object,
     open tun/tap device, ifconfig, run up script, etc. */
  if (!(options->up_delay || PULL_DEFINED (options)) && (c->mode == CM_P2P || c->mode == CM_TOP))
    c->c2.did_open_tun = do_open_tun (c);

  /* print MTU info */
  do_print_data_channel_mtu_parms (c);

#ifdef ENABLE_OCC
  /* get local and remote options compatibility strings */
  if (c->mode == CM_P2P || child)
    do_compute_occ_strings (c);
#endif

  /* initialize output speed limiter */
  if (c->mode == CM_P2P)
    do_init_traffic_shaper (c);

  /* do one-time inits, and possibily become a daemon here */
  do_init_first_time (c);

#ifdef ENABLE_PLUGIN
  /* initialize plugins */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    open_plugins (c, false, OPENVPN_PLUGIN_INIT_POST_DAEMON);
#endif

  /*
   * Actually do UID/GID downgrade, and chroot, if requested.
   * May be delayed by --client, --pull, or --up-delay.
   */
  do_uid_gid_chroot (c, c->c2.did_open_tun);

  /* finalize the TCP/UDP socket */
  if (c->mode == CM_P2P || c->mode == CM_TOP || c->mode == CM_CHILD_TCP)
    do_init_socket_2 (c);

  /* initialize timers */
  if (c->mode == CM_P2P || child)
    do_init_timers (c, false);

#ifdef ENABLE_PLUGIN
  /* initialize plugins */
  if (c->mode == CM_P2P || c->mode == CM_TOP)
    open_plugins (c, false, OPENVPN_PLUGIN_INIT_POST_UID_CHANGE);
#endif

#if PORT_SHARE
  /* share OpenVPN port with foreign (such as HTTPS) server */
  if (c->first_time && (c->mode == CM_P2P || c->mode == CM_TOP))
    init_port_share (c);
#endif
	  
  /* Check for signals */
  if (IS_SIG (c))
    goto sig;

  return;

 sig:
  if (!c->sig->signal_text)
    c->sig->signal_text = "init_instance";
  close_context (c, -1, flags);
  return;
}

/*
 * Close a tunnel instance.
 */
void
close_instance (struct context *c)
{
  /* close event objects */
  do_close_event_set (c);

    if (c->mode == CM_P2P
	|| c->mode == CM_CHILD_TCP
	|| c->mode == CM_CHILD_UDP
	|| c->mode == CM_TOP)
      {
	/* if xinetd/inetd mode, don't allow restart */
	do_close_check_if_restart_permitted (c);

#ifdef USE_LZO
	if (lzo_defined (&c->c2.lzo_compwork))
	  lzo_compress_uninit (&c->c2.lzo_compwork);
#endif

	/* free buffers */
	do_close_free_buf (c);

	/* close TLS */
	do_close_tls (c);

	/* free key schedules */
	do_close_free_key_schedule (c, (c->mode == CM_P2P || c->mode == CM_TOP));

	/* close TCP/UDP connection */
	do_close_link_socket (c);

	/* close TUN/TAP device */
	do_close_tun (c, false);

#ifdef ENABLE_PLUGIN
	/* call plugin close functions and unload */
	do_close_plugins (c);
#endif

	/* close packet-id persistance file */
	do_close_packet_id (c);

	/* close --status file */
	do_close_status_output (c);

#ifdef ENABLE_FRAGMENT
	/* close fragmentation handler */
	do_close_fragment (c);
#endif

	/* close --ifconfig-pool-persist obj */
	do_close_ifconfig_pool_persist (c);

	/* garbage collect */
	gc_free (&c->c2.gc);
      }
}

void
inherit_context_child (struct context *dest,
		       const struct context *src)
{
  CLEAR (*dest);

  switch (src->options.proto)
    {
    case PROTO_UDPv4:
      dest->mode = CM_CHILD_UDP;
      break;
    case PROTO_TCPv4_SERVER:
      dest->mode = CM_CHILD_TCP;
      break;
    default:
      ASSERT (0);
    }

  dest->gc = gc_new ();

  ALLOC_OBJ_CLEAR_GC (dest->sig, struct signal_info, &dest->gc);

  /* c1 init */
  packet_id_persist_init (&dest->c1.pid_persist);

#ifdef USE_CRYPTO
  dest->c1.ks.key_type = src->c1.ks.key_type;
#ifdef USE_SSL
  /* inherit SSL context */
  dest->c1.ks.ssl_ctx = src->c1.ks.ssl_ctx;
  dest->c1.ks.tls_auth_key = src->c1.ks.tls_auth_key;
#endif
#endif

  /* options */
  dest->options = src->options;
  options_detach (&dest->options);

  if (dest->mode == CM_CHILD_TCP)
    {
      /*
       * The CM_TOP context does the socket listen(),
       * and the CM_CHILD_TCP context does the accept().
       */
      dest->c2.accept_from = src->c2.link_socket;
    }

#ifdef ENABLE_PLUGIN
  /* inherit plugins */
  do_inherit_plugins (dest, src);
#endif

  /* context init */
  init_instance (dest, src->c2.es, CC_NO_CLOSE | CC_USR1_TO_HUP);
  if (IS_SIG (dest))
    return;

  /* inherit tun/tap interface object */
  dest->c1.tuntap = src->c1.tuntap;

  /* UDP inherits some extra things which TCP does not */
  if (dest->mode == CM_CHILD_UDP)
    {
      /* inherit buffers */
      dest->c2.buffers = src->c2.buffers;

      /* inherit parent link_socket and tuntap */
      dest->c2.link_socket = src->c2.link_socket;

      ALLOC_OBJ_GC (dest->c2.link_socket_info, struct link_socket_info, &dest->gc);
      *dest->c2.link_socket_info = src->c2.link_socket->info;

      /* locally override some link_socket_info fields */
      dest->c2.link_socket_info->lsa = &dest->c1.link_socket_addr;
      dest->c2.link_socket_info->connection_established = false;
    }
}

void
inherit_context_top (struct context *dest,
		     const struct context *src)
{
  /* copy parent */
  *dest = *src;

  /*
   * CM_TOP_CLONE will prevent close_instance from freeing or closing
   * resources owned by the parent.
   *
   * Also note that CM_TOP_CLONE context objects are
   * closed by multi_top_free in multi.c.
   */
  dest->mode = CM_TOP_CLONE; 

  dest->first_time = false;
  dest->c0 = NULL;

  options_detach (&dest->options);
  gc_detach (&dest->gc);
  gc_detach (&dest->c2.gc);

  /* detach plugins */
  dest->plugins_owned = false;

#if defined(USE_CRYPTO) && defined(USE_SSL)
  dest->c2.tls_multi = NULL;
#endif

  /* detach c1 ownership */
  dest->c1.tuntap_owned = false;
  dest->c1.status_output_owned = false;
#if P2MP_SERVER
  dest->c1.ifconfig_pool_persist_owned = false;
#endif

  /* detach c2 ownership */
  dest->c2.event_set_owned = false;
  dest->c2.link_socket_owned = false;
  dest->c2.buffers_owned = false;

  dest->c2.event_set = NULL;
  if (src->options.proto == PROTO_UDPv4)
    do_event_set_init (dest, false);
}

void
close_context (struct context *c, int sig, unsigned int flags)
{
  ASSERT (c);
  ASSERT (c->sig);

  if (sig >= 0)
    c->sig->signal_received = sig;

  if (c->sig->signal_received == SIGUSR1)
    {
      if ((flags & CC_USR1_TO_HUP)
	  || (c->sig->hard && (flags & CC_HARD_USR1_TO_HUP)))
	c->sig->signal_received = SIGHUP;
    }

  if (!(flags & CC_NO_CLOSE))
    close_instance (c);

  if (flags & CC_GC_FREE)
    context_gc_free (c);
}

#ifdef USE_CRYPTO

static void
test_malloc (void)
{
  int i, j;
  msg (M_INFO, "Multithreaded malloc test...");
  for (i = 0; i < 25; ++i)
    {
      struct gc_arena gc = gc_new ();
      const int limit = get_random () & 0x03FF;
      for (j = 0; j < limit; ++j)
	{
	  gc_malloc (get_random () & 0x03FF, false, &gc);
	}
      gc_free (&gc);
    }
}

/*
 * Do a loopback test
 * on the crypto subsystem.
 */
static void *
test_crypto_thread (void *arg)
{
  struct context *c = (struct context *) arg;
  const struct options *options = &c->options;
#if defined(USE_PTHREAD)
  struct context *child = NULL;
  openvpn_thread_t child_id = 0;
#endif

  ASSERT (options->test_crypto);
  init_verb_mute (c, IVM_LEVEL_1);
  context_init_1 (c);
  do_init_crypto_static (c, 0);

#if defined(USE_PTHREAD)
  {
    if (c->first_time && options->n_threads > 1)
      {
	if (options->n_threads > 2)
	  msg (M_FATAL, "ERROR: --test-crypto option only works with --threads set to 1 or 2");
	openvpn_thread_init ();
	ALLOC_OBJ (child, struct context);
	context_clear (child);
	child->options = *options;
	options_detach (&child->options);
	child->first_time = false;
	child_id = openvpn_thread_create (test_crypto_thread, (void *) child);
      }
  }
#endif
  frame_finalize_options (c, options);

#if defined(USE_PTHREAD)
  if (options->n_threads == 2)
    test_malloc ();
#endif

  test_crypto (&c->c2.crypto_options, &c->c2.frame);

  key_schedule_free (&c->c1.ks, true);
  packet_id_free (&c->c2.packet_id);

#if defined(USE_PTHREAD)
  if (c->first_time && options->n_threads > 1)
    openvpn_thread_join (child_id);
  if (child)
    free (child);
#endif
  context_gc_free (c);
  return NULL;
}

#endif

bool
do_test_crypto (const struct options *o)
{
#ifdef USE_CRYPTO
  if (o->test_crypto)
    {
      struct context c;

      /* print version number */
      msg (M_INFO, "%s", title_string);

      context_clear (&c);
      c.options = *o;
      options_detach (&c.options);
      c.first_time = true;
      test_crypto_thread ((void *) &c);
      return true;
    }
#endif
  return false;
}