removed openvpn source code

1 files changed, 0 insertions, 3446 deletions

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
deleted file mode 100644
index e904a0c..0000000
--- a/src/openvpn/tun.c
+++ /dev/null
@@ -1,3446 +0,0 @@
-/*
- *  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
- */
-
-/*
- * Support routines for configuring and accessing TUN/TAP
- * virtual network adapters.
- *
- * This file is based on the TUN/TAP driver interface routines
- * from VTun by Maxim Krasnyansky <max_mk@yahoo.com>.
- */
-
-#ifdef WIN32
-#include "config-win32.h"
-#else
-#include "config.h"
-#endif
-
-#include "syshead.h"
-
-#include "tun.h"
-#include "fdmisc.h"
-#include "common.h"
-#include "misc.h"
-#include "socket.h"
-#include "manage.h"
-
-#include "memdbg.h"
-
-#ifdef TARGET_SOLARIS
-static void solaris_error_close (struct tuntap *tt, const struct env_set *es, const char *actual);
-#endif
-
-bool
-is_dev_type (const char *dev, const char *dev_type, const char *match_type)
-{
-  ASSERT (match_type);
-  if (!dev)
-    return false;
-  if (dev_type)
-    return !strcmp (dev_type, match_type);
-  else
-    return !strncmp (dev, match_type, strlen (match_type));
-}
-
-int
-dev_type_enum (const char *dev, const char *dev_type)
-{
-  if (is_dev_type (dev, dev_type, "tun"))
-    return DEV_TYPE_TUN;
-  else if (is_dev_type (dev, dev_type, "tap"))
-    return DEV_TYPE_TAP;
-  else if (is_dev_type (dev, dev_type, "null"))
-    return DEV_TYPE_NULL;
-  else
-    return DEV_TYPE_UNDEF;
-}
-
-const char *
-dev_type_string (const char *dev, const char *dev_type)
-{
-  switch (dev_type_enum (dev, dev_type))
-    {
-    case DEV_TYPE_TUN:
-      return "tun";
-    case DEV_TYPE_TAP:
-      return "tap";
-    case DEV_TYPE_NULL:
-      return "null";
-    default:
-      return "[unknown-dev-type]";
-    }
-}
-
-const char *
-dev_component_in_dev_node (const char *dev_node)
-{
-  const char *ret;
-  const int dirsep = OS_SPECIFIC_DIRSEP;
-
-  if (dev_node)
-    {
-      ret = strrchr (dev_node, dirsep);
-      if (ret && *ret)
-	++ret;
-      else
-	ret = dev_node;
-      if (*ret)
-	return ret;
-    }
-  return NULL;
-}
-
-/*
- * Try to predict the actual TUN/TAP device instance name,
- * before the device is actually opened.
- */
-const char *
-guess_tuntap_dev (const char *dev,
-		  const char *dev_type,
-		  const char *dev_node,
-		  struct gc_arena *gc)
-{
-#ifdef WIN32
-  const int dt = dev_type_enum (dev, dev_type);
-  if (dt == DEV_TYPE_TUN || dt == DEV_TYPE_TAP)
-    {
-      return get_netsh_id (dev_node, gc);
-    }
-#endif
-
-  /* default case */
-  return dev;
-}
-
-/*
- * Called by the open_tun function of OSes to check if we
- * explicitly support IPv6.
- *
- * In this context, explicit means that the OS expects us to
- * do something special to the tun socket in order to support
- * IPv6, i.e. it is not transparent.
- *
- * ipv6_explicitly_supported should be set to false if we don't
- * have any explicit IPv6 code in the tun device handler.
- *
- * If ipv6_explicitly_supported is true, then we have explicit
- * OS-specific tun dev code for handling IPv6.  If so, tt->ipv6
- * is set according to the --tun-ipv6 command line option.
- */
-static void
-ipv6_support (bool ipv6, bool ipv6_explicitly_supported, struct tuntap* tt)
-{
-  tt->ipv6 = false;
-  if (ipv6_explicitly_supported)
-    tt->ipv6 = ipv6;
-  else if (ipv6)
-    msg (M_WARN, "NOTE: explicit support for IPv6 tun devices is not provided for this OS");
-}
-
-/* --ifconfig-nowarn disables some options sanity checking */
-static const char ifconfig_warn_how_to_silence[] = "(silence this warning with --ifconfig-nowarn)";
-
-/*
- * If !tun, make sure ifconfig_remote_netmask looks
- *  like a netmask.
- *
- * If tun, make sure ifconfig_remote_netmask looks
- *  like an IPv4 address.
- */
-static void
-ifconfig_sanity_check (bool tun, in_addr_t addr)
-{
-  struct gc_arena gc = gc_new ();
-  const bool looks_like_netmask = ((addr & 0xFF000000) == 0xFF000000);
-  if (tun)
-    {
-      if (looks_like_netmask)
-	msg (M_WARN, "WARNING: Since you are using --dev tun, the second argument to --ifconfig must be an IP address.  You are using something (%s) that looks more like a netmask. %s",
-	     print_in_addr_t (addr, 0, &gc),
-	     ifconfig_warn_how_to_silence);
-    }
-  else /* tap */
-    {
-      if (!looks_like_netmask)
-	msg (M_WARN, "WARNING: Since you are using --dev tap, the second argument to --ifconfig must be a netmask, for example something like 255.255.255.0. %s",
-	     ifconfig_warn_how_to_silence);
-    }
-  gc_free (&gc);
-}
-
-/*
- * For TAP-style devices, generate a broadcast address.
- */
-static in_addr_t
-generate_ifconfig_broadcast_addr (in_addr_t local,
-				  in_addr_t netmask)
-{
-  return local | ~netmask;
-}
-
-/*
- * Check that --local and --remote addresses do not
- * clash with ifconfig addresses or subnet.
- */
-static void
-check_addr_clash (const char *name,
-		  int type,
-		  in_addr_t public,
-		  in_addr_t local,
-		  in_addr_t remote_netmask)
-{
-  struct gc_arena gc = gc_new ();
-#if 0
-  msg (M_INFO, "CHECK_ADDR_CLASH type=%d public=%s local=%s, remote_netmask=%s",
-       type,
-       print_in_addr_t (public, 0, &gc),
-       print_in_addr_t (local, 0, &gc),
-       print_in_addr_t (remote_netmask, 0, &gc));
-#endif
-
-  if (public)
-    {
-      if (type == DEV_TYPE_TUN)
-	{
-	  const in_addr_t test_netmask = 0xFFFFFF00;
-	  const in_addr_t public_net = public & test_netmask;
-	  const in_addr_t local_net = local & test_netmask;
-	  const in_addr_t remote_net = remote_netmask & test_netmask;
-
-	  if (public == local || public == remote_netmask)
-	    msg (M_WARN,
-		 "WARNING: --%s address [%s] conflicts with --ifconfig address pair [%s, %s]. %s",
-		 name,
-		 print_in_addr_t (public, 0, &gc),
-		 print_in_addr_t (local, 0, &gc),
-		 print_in_addr_t (remote_netmask, 0, &gc),
-		 ifconfig_warn_how_to_silence);
-
-	  if (public_net == local_net || public_net == remote_net)
-	    msg (M_WARN,
-		 "WARNING: potential conflict between --%s address [%s] and --ifconfig address pair [%s, %s] -- this is a warning only that is triggered when local/remote addresses exist within the same /24 subnet as --ifconfig endpoints. %s",
-		 name,
-		 print_in_addr_t (public, 0, &gc),
-		 print_in_addr_t (local, 0, &gc),
-		 print_in_addr_t (remote_netmask, 0, &gc),
-		 ifconfig_warn_how_to_silence);
-	}
-      else if (type == DEV_TYPE_TAP)
-	{
-	  const in_addr_t public_network = public & remote_netmask;
-	  const in_addr_t virtual_network = local & remote_netmask;
-	  if (public_network == virtual_network)
-	    msg (M_WARN,
-		 "WARNING: --%s address [%s] conflicts with --ifconfig subnet [%s, %s] -- local and remote addresses cannot be inside of the --ifconfig subnet. %s",
-		 name,
-		 print_in_addr_t (public, 0, &gc),
-		 print_in_addr_t (local, 0, &gc),
-		 print_in_addr_t (remote_netmask, 0, &gc),
-		 ifconfig_warn_how_to_silence);
-	}
-    }
-  gc_free (&gc);
-}
-
-/*
- * Complain if --dev tap and --ifconfig is used on an OS for which
- * we don't have a custom tap ifconfig template below.
- */
-static void
-no_tap_ifconfig ()
-{
-  msg (M_FATAL, "Sorry but you cannot use --dev tap and --ifconfig together on this OS because I have not yet been programmed to understand the appropriate ifconfig syntax to use for TAP-style devices on this OS.  Your best alternative is to use an --up script and do the ifconfig command manually.");
-}
-
-/*
- * Return a string to be used for options compatibility check
- * between peers.
- */
-const char *
-ifconfig_options_string (const struct tuntap* tt, bool remote, bool disable, struct gc_arena *gc)
-{
-  struct buffer out = alloc_buf_gc (256, gc);
-  if (tt->did_ifconfig_setup && !disable)
-    {
-      if (tt->type == DEV_TYPE_TUN)
-	{
-	  const char *l, *r;
-	  if (remote)
-	    {
-	      r = print_in_addr_t (tt->local, 0, gc);
-	      l = print_in_addr_t (tt->remote_netmask, 0, gc);
-	    }
-	  else
-	    {
-	      l = print_in_addr_t (tt->local, 0, gc);
-	      r = print_in_addr_t (tt->remote_netmask, 0, gc);
-	    }
-	  buf_printf (&out, "%s %s", r, l);
-	}
-      else if (tt->type == DEV_TYPE_TAP)
-	{
-	  buf_printf (&out, "%s %s",
-		      print_in_addr_t (tt->local & tt->remote_netmask, 0, gc),
-		      print_in_addr_t (tt->remote_netmask, 0, gc));
-	}
-      else
-	buf_printf (&out, "[undef]");
-    }
-  return BSTR (&out);
-}
-
-/*
- * Return a status string describing wait state.
- */
-const char *
-tun_stat (const struct tuntap *tt, unsigned int rwflags, struct gc_arena *gc)
-{
-  struct buffer out = alloc_buf_gc (64, gc);
-  if (tt)
-    {
-      if (rwflags & EVENT_READ)
-	{
-	  buf_printf (&out, "T%s",
-		      (tt->rwflags_debug & EVENT_READ) ? "R" : "r");
-#ifdef WIN32
-	  buf_printf (&out, "%s",
-		      overlapped_io_state_ascii (&tt->reads));
-#endif
-	}
-      if (rwflags & EVENT_WRITE)
-	{
-	  buf_printf (&out, "T%s",
-		      (tt->rwflags_debug & EVENT_WRITE) ? "W" : "w");
-#ifdef WIN32
-	  buf_printf (&out, "%s",
-		      overlapped_io_state_ascii (&tt->writes));
-#endif
-	}
-    }
-  else
-    {
-      buf_printf (&out, "T?");
-    }
-  return BSTR (&out);
-}
-
-/*
- * Init tun/tap object.
- *
- * Set up tuntap structure for ifconfig,
- * but don't execute yet.
- */
-struct tuntap *
-init_tun (const char *dev,       /* --dev option */
-	  const char *dev_type,  /* --dev-type option */
-	  const char *ifconfig_local_parm,          /* --ifconfig parm 1 */
-	  const char *ifconfig_remote_netmask_parm, /* --ifconfig parm 2 */
-	  in_addr_t local_public,
-	  in_addr_t remote_public,
-	  const bool strict_warn,
-	  struct env_set *es)
-{
-  struct gc_arena gc = gc_new ();
-  struct tuntap *tt;
-
-  ALLOC_OBJ (tt, struct tuntap);
-  clear_tuntap (tt);
-
-  tt->type = dev_type_enum (dev, dev_type);
-
-  if (ifconfig_local_parm && ifconfig_remote_netmask_parm)
-    {
-      bool tun = false;
-      const char *ifconfig_local = NULL;
-      const char *ifconfig_remote_netmask = NULL;
-      const char *ifconfig_broadcast = NULL;
-
-      /*
-       * We only handle TUN/TAP devices here, not --dev null devices.
-       */
-      if (tt->type == DEV_TYPE_TUN)
-	tun = true;
-      else if (tt->type == DEV_TYPE_TAP)
-	tun = false;
-      else
-	msg (M_FATAL, "'%s' is not a TUN/TAP device.  The --ifconfig option works only for TUN/TAP devices.", dev);
-
-      /*
-       * Convert arguments to binary IPv4 addresses.
-       */
-
-      tt->local = getaddr (
-			   GETADDR_RESOLVE
-			   | GETADDR_HOST_ORDER
-			   | GETADDR_FATAL_ON_SIGNAL
-			   | GETADDR_FATAL,
-			   ifconfig_local_parm,
-			   0,
-			   NULL,
-			   NULL);
-
-      tt->remote_netmask = getaddr (
-				    (tun ? GETADDR_RESOLVE : 0)
-				    | GETADDR_HOST_ORDER
-				    | GETADDR_FATAL_ON_SIGNAL
-				    | GETADDR_FATAL,
-				    ifconfig_remote_netmask_parm,
-				    0,
-				    NULL,
-				    NULL);
-
-      /*
-       * Look for common errors in --ifconfig parms
-       */
-      if (strict_warn)
-	{
-	  ifconfig_sanity_check (tun, tt->remote_netmask);
-
-	  /*
-	   * If local_public or remote_public addresses are defined,
-	   * make sure they do not clash with our virtual subnet.
-	   */
-
-	  check_addr_clash ("local",
-			    tt->type,
-			    local_public,
-			    tt->local,
-			    tt->remote_netmask);
-
-	  check_addr_clash ("remote",
-			    tt->type,
-			    remote_public,
-			    tt->local,
-			    tt->remote_netmask);
-	}
-
-      /*
-       * Set ifconfig parameters
-       */
-      ifconfig_local = print_in_addr_t (tt->local, 0, &gc);
-      ifconfig_remote_netmask = print_in_addr_t (tt->remote_netmask, 0, &gc);
-
-      /*
-       * If TAP-style interface, generate broadcast address.
-       */
-      if (!tun)
-	{
-	  tt->broadcast = generate_ifconfig_broadcast_addr (tt->local, tt->remote_netmask);
-	  ifconfig_broadcast = print_in_addr_t (tt->broadcast, 0, &gc);
-	}
-
-      /*
-       * Set environmental variables with ifconfig parameters.
-       */
-      if (es)
-	{
-	  setenv_str (es, "ifconfig_local", ifconfig_local);
-	  if (tun)
-	    {
-	      setenv_str (es, "ifconfig_remote", ifconfig_remote_netmask);
-	    }
-	  else
-	    {
-	      setenv_str (es, "ifconfig_netmask", ifconfig_remote_netmask);
-	      setenv_str (es, "ifconfig_broadcast", ifconfig_broadcast);
-	    }
-	}
-
-      tt->did_ifconfig_setup = true;
-    }
-  gc_free (&gc);
-  return tt;
-}
-
-/*
- * Platform specific tun initializations
- */
-void
-init_tun_post (struct tuntap *tt,
-	       const struct frame *frame,
-	       const struct tuntap_options *options)
-{
-  tt->options = *options;
-#ifdef WIN32
-  overlapped_io_init (&tt->reads, frame, FALSE, true);
-  overlapped_io_init (&tt->writes, frame, TRUE, true);
-  tt->rw_handle.read = tt->reads.overlapped.hEvent;
-  tt->rw_handle.write = tt->writes.overlapped.hEvent;
-  tt->adapter_index = ~0;
-#endif
-}
-
-/* execute the ifconfig command through the shell */
-void
-do_ifconfig (struct tuntap *tt,
-	     const char *actual,    /* actual device name */
-	     int tun_mtu,
-	     const struct env_set *es)
-{
-  struct gc_arena gc = gc_new ();
-
-  if (tt->did_ifconfig_setup)
-    {
-      bool tun = false;
-      const char *ifconfig_local = NULL;
-      const char *ifconfig_remote_netmask = NULL;
-      const char *ifconfig_broadcast = NULL;
-      char command_line[256];
-
-      /*
-       * We only handle TUN/TAP devices here, not --dev null devices.
-       */
-      if (tt->type == DEV_TYPE_TUN)
-	tun = true;
-      else if (tt->type == DEV_TYPE_TAP)
-	tun = false;
-      else
-	ASSERT (0); /* should have been caught in init_tun */
-
-      /*
-       * Set ifconfig parameters
-       */
-      ifconfig_local = print_in_addr_t (tt->local, 0, &gc);
-      ifconfig_remote_netmask = print_in_addr_t (tt->remote_netmask, 0, &gc);
-
-      /*
-       * If TAP-style device, generate broadcast address.
-       */
-      if (!tun)
-	ifconfig_broadcast = print_in_addr_t (tt->broadcast, 0, &gc);
-
-#ifdef ENABLE_MANAGEMENT
-  if (management)
-    {
-      management_set_state (management,
-			    OPENVPN_STATE_ASSIGN_IP,
-			    NULL,
-			    tt->local);
-    }
-#endif
-
-
-#if defined(TARGET_LINUX)
-#ifdef CONFIG_FEATURE_IPROUTE
-	/*
-	 * Set the MTU for the device
-	 */
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IPROUTE_PATH " link set dev %s up mtu %d",
-			  actual,
-			  tun_mtu
-			  );
-	  msg (M_INFO, "%s", command_line);
-	  system_check (command_line, es, S_FATAL, "Linux ip link set failed");
-
-	if (tun) {
-
-		/*
-		 * Set the address for the device
-		 */
-		openvpn_snprintf (command_line, sizeof (command_line),
-				  IPROUTE_PATH " addr add dev %s local %s peer %s",
-				  actual,
-				  ifconfig_local,
-				  ifconfig_remote_netmask
-				  );
-		  msg (M_INFO, "%s", command_line);
-		  system_check (command_line, es, S_FATAL, "Linux ip addr add failed");
-	} else {
-		openvpn_snprintf (command_line, sizeof (command_line),
-				  IPROUTE_PATH " addr add dev %s %s/%d broadcast %s",
-				  actual,
-				  ifconfig_local,
-				  count_netmask_bits(ifconfig_remote_netmask),
-				  ifconfig_broadcast
-				  );
-		  msg (M_INFO, "%s", command_line);
-		  system_check (command_line, es, S_FATAL, "Linux ip addr add failed");
-	}
-	tt->did_ifconfig = true;
-#else
-      if (tun)
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s pointopoint %s mtu %d",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-      else
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s netmask %s mtu %d broadcast %s",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu,
-			  ifconfig_broadcast
-			  );
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, S_FATAL, "Linux ifconfig failed");
-      tt->did_ifconfig = true;
-
-#endif /*CONFIG_FEATURE_IPROUTE*/
-#elif defined(TARGET_SOLARIS)
-
-      /* Solaris 2.6 (and 7?) cannot set all parameters in one go...
-       * example:
-       *    ifconfig tun2 10.2.0.2 10.2.0.1 mtu 1450 up
-       *    ifconfig tun2 netmask 255.255.255.255
-       */
-      if (tun)
-	{
-	  openvpn_snprintf (command_line, sizeof (command_line),
-			    IFCONFIG_PATH " %s %s %s mtu %d up",
-			    actual,
-			    ifconfig_local,
-			    ifconfig_remote_netmask,
-			    tun_mtu
-			    );
-
-	  msg (M_INFO, "%s", command_line);
-	  if (!system_check (command_line, es, 0, "Solaris ifconfig phase-1 failed"))
-	    solaris_error_close (tt, es, actual);
-
-	  openvpn_snprintf (command_line, sizeof (command_line),
-			    IFCONFIG_PATH " %s netmask 255.255.255.255",
-			    actual
-			    );
-	}
-      else
-	no_tap_ifconfig ();
-
-      msg (M_INFO, "%s", command_line);
-      if (!system_check (command_line, es, 0, "Solaris ifconfig phase-2 failed"))
-	solaris_error_close (tt, es, actual);
-
-      tt->did_ifconfig = true;
-
-#elif defined(TARGET_OPENBSD)
-
-      /*
-       * OpenBSD tun devices appear to be persistent by default.  It seems in order
-       * to make this work correctly, we need to delete the previous instance
-       * (if it exists), and re-ifconfig.  Let me know if you know a better way.
-       */
-
-      openvpn_snprintf (command_line, sizeof (command_line),
-			IFCONFIG_PATH " %s destroy",
-			actual);
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, 0, NULL);
-      openvpn_snprintf (command_line, sizeof (command_line),
-			IFCONFIG_PATH " %s create",
-			actual);
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, 0, NULL);
-      msg (M_INFO, "NOTE: Tried to delete pre-existing tun/tap instance -- No Problem if failure");
-
-      /* example: ifconfig tun2 10.2.0.2 10.2.0.1 mtu 1450 netmask 255.255.255.255 up */
-      if (tun)
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s %s mtu %d netmask 255.255.255.255 up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-      else
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s netmask %s mtu %d broadcast %s link0",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu,
-			  ifconfig_broadcast
-			  );
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, S_FATAL, "OpenBSD ifconfig failed");
-      tt->did_ifconfig = true;
-
-#elif defined(TARGET_NETBSD)
-
-      if (tun)
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s %s mtu %d netmask 255.255.255.255 up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-      else
-      /*
-       * NetBSD has distinct tun and tap devices
-       * so we don't need the "link0" extra parameter to specify we want to do 
-       * tunneling at the ethernet level
-       */
-		openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s netmask %s mtu %d broadcast %s",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu,
-			  ifconfig_broadcast
-			  );
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, S_FATAL, "NetBSD ifconfig failed");
-      tt->did_ifconfig = true;
-
-#elif defined(TARGET_DARWIN)
-
-      /*
-       * Darwin (i.e. Mac OS X) seems to exhibit similar behaviour to OpenBSD...
-       */
-
-      openvpn_snprintf (command_line, sizeof (command_line),
-			IFCONFIG_PATH " %s delete",
-			actual);
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, 0, NULL);
-      msg (M_INFO, "NOTE: Tried to delete pre-existing tun/tap instance -- No Problem if failure");
-
-
-      /* example: ifconfig tun2 10.2.0.2 10.2.0.1 mtu 1450 netmask 255.255.255.255 up */
-      if (tun)
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s %s mtu %d netmask 255.255.255.255 up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-      else
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s netmask %s mtu %d up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, S_FATAL, "Mac OS X ifconfig failed");
-      tt->did_ifconfig = true;
-
-#elif defined(TARGET_FREEBSD)
-
-      /* example: ifconfig tun2 10.2.0.2 10.2.0.1 mtu 1450 netmask 255.255.255.255 up */
-      if (tun)
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s %s mtu %d netmask 255.255.255.255 up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-      else
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  IFCONFIG_PATH " %s %s netmask %s mtu %d up",
-			  actual,
-			  ifconfig_local,
-			  ifconfig_remote_netmask,
-			  tun_mtu
-			  );
-	
-      msg (M_INFO, "%s", command_line);
-      system_check (command_line, es, S_FATAL, "FreeBSD ifconfig failed");
-      tt->did_ifconfig = true;
-
-#elif defined (WIN32)
-      {
-	const char *netmask;
-
-	/*
-	 * Make sure that both ifconfig addresses are part of the
-	 * same .252 subnet.
-	 */
-	if (tun)
-	  {
-	    verify_255_255_255_252 (tt->local, tt->remote_netmask);
-	    tt->adapter_netmask = ~3;
-	    netmask = print_in_addr_t (tt->adapter_netmask, 0, &gc);
-	  }
-	else
-	  {
-	    netmask = ifconfig_remote_netmask;
-	    tt->adapter_netmask = tt->remote_netmask;
-	  }
-
-	/* example: netsh interface ip set address my-tap static 10.3.0.1 255.255.255.0 */
-	openvpn_snprintf (command_line, sizeof (command_line),
-			  "netsh interface ip set address \"%s\" static %s %s",
-			  actual,
-			  ifconfig_local,
-			  netmask);
-	
-	switch (tt->options.ip_win32_type)
-	  {
-	  case IPW32_SET_MANUAL:
-	    msg (M_INFO, "******** NOTE:  Please manually set the IP/netmask of '%s' to %s/%s (if it is not already set)",
-		 actual,
-		 ifconfig_local,
-		 netmask);
-	    break;
-	  case IPW32_SET_NETSH:
-	    if (!strcmp (actual, "NULL"))
-	      msg (M_FATAL, "Error: When using --ip-win32 netsh, if you have more than one TAP-Win32 adapter, you must also specify --dev-node");
-	    netcmd_semaphore_lock ();
-	    msg (M_INFO, "%s", command_line);
-	    system_check (command_line, es, S_FATAL, "ERROR: netsh command failed");
-	    netcmd_semaphore_release ();
-	    break;
-	  }
-	tt->did_ifconfig = true;
-      }
-
-#else
-      msg (M_FATAL, "Sorry, but I don't know how to do 'ifconfig' commands on this operating system.  You should ifconfig your TUN/TAP device manually or use an --up script.");
-#endif
-    }
-  gc_free (&gc);
-}
-
-void
-clear_tuntap (struct tuntap *tuntap)
-{
-  CLEAR (*tuntap);
-#ifdef WIN32
-  tuntap->hand = NULL;
-#else
-  tuntap->fd = -1;
-#endif
-#ifdef TARGET_SOLARIS
-  tuntap->ip_fd = -1;
-#endif
-  tuntap->ipv6 = false;
-}
-
-static void
-open_null (struct tuntap *tt)
-{
-  tt->actual_name = string_alloc ("null", NULL);
-}
-
-#ifndef WIN32
-static void
-open_tun_generic (const char *dev, const char *dev_type, const char *dev_node,
-		  bool ipv6, bool ipv6_explicitly_supported, bool dynamic,
-		  struct tuntap *tt)
-{
-  char tunname[256];
-  char dynamic_name[256];
-  bool dynamic_opened = false;
-
-  ipv6_support (ipv6, ipv6_explicitly_supported, tt);
-
-  if (tt->type == DEV_TYPE_NULL)
-    {
-      open_null (tt);
-    }
-  else
-    {
-      /*
-       * --dev-node specified, so open an explicit device node
-       */
-      if (dev_node)
-	{
-	  openvpn_snprintf (tunname, sizeof (tunname), "%s", dev_node);
-	}
-      else
-	{
-	  /*
-	   * dynamic open is indicated by --dev specified without
-	   * explicit unit number.  Try opening /dev/[dev]n
-	   * where n = [0, 255].
-	   */
-	  if (dynamic && !has_digit(dev))
-	    {
-	      int i;
-	      for (i = 0; i < 256; ++i)
-		{
-		  openvpn_snprintf (tunname, sizeof (tunname),
-				    "/dev/%s%d", dev, i);
-		  openvpn_snprintf (dynamic_name, sizeof (dynamic_name),
-				    "%s%d", dev, i);
-		  if ((tt->fd = open (tunname, O_RDWR)) > 0)
-		    {
-		      dynamic_opened = true;
-		      break;
-		    }
-		  msg (D_READ_WRITE | M_ERRNO, "Tried opening %s (failed)", tunname);
-		}
-	      if (!dynamic_opened)
-		msg (M_FATAL, "Cannot allocate TUN/TAP dev dynamically");
-	    }
-	  /*
-	   * explicit unit number specified
-	   */
-	  else
-	    {
-	      openvpn_snprintf (tunname, sizeof (tunname), "/dev/%s", dev);
-	    }
-	}
-
-      if (!dynamic_opened)
-	{
-	  if ((tt->fd = open (tunname, O_RDWR)) < 0)
-	    msg (M_ERR, "Cannot open TUN/TAP dev %s", tunname);
-	}
-
-      set_nonblock (tt->fd);
-      set_cloexec (tt->fd); /* don't pass fd to scripts */
-      msg (M_INFO, "TUN/TAP device %s opened", tunname);
-
-      /* tt->actual_name is passed to up and down scripts and used as the ifconfig dev name */
-      tt->actual_name = string_alloc (dynamic_opened ? dynamic_name : dev, NULL);
-    }
-}
-
-static void
-close_tun_generic (struct tuntap *tt)
-{
-  if (tt->fd >= 0)
-    close (tt->fd);
-  if (tt->actual_name)
-    free (tt->actual_name);
-  clear_tuntap (tt);
-}
-
-#endif
-
-#if defined(TARGET_LINUX)
-
-#ifdef HAVE_LINUX_IF_TUN_H	/* New driver support */
-
-#ifndef HAVE_LINUX_SOCKIOS_H
-#error header file linux/sockios.h required
-#endif
-
-#if defined(HAVE_TUN_PI) && defined(HAVE_IPHDR) && defined(HAVE_IOVEC) && defined(ETH_P_IPV6) && defined(ETH_P_IP) && defined(HAVE_READV) && defined(HAVE_WRITEV)
-#define LINUX_IPV6 1
-/* #warning IPv6 ON */
-#else
-#define LINUX_IPV6 0
-/* #warning IPv6 OFF */
-#endif
-
-#if !PEDANTIC
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  struct ifreq ifr;
-
-  /*
-   * Set tt->ipv6 to true if
-   * (a) we have the capability of supporting --tun-ipv6, and
-   * (b) --tun-ipv6 was specified.
-   */
-  ipv6_support (ipv6, LINUX_IPV6, tt);
-
-  /*
-   * We handle --dev null specially, we do not open /dev/null for this.
-   */
-  if (tt->type == DEV_TYPE_NULL)
-    {
-      open_null (tt);
-    }
-  else
-    {
-      /*
-       * Process --dev-node
-       */
-      const char *node = dev_node;
-      if (!node)
-	node = "/dev/net/tun";
-
-      /*
-       * Open the interface
-       */
-      if ((tt->fd = open (node, O_RDWR)) < 0)
-	{
-	  msg (M_WARN | M_ERRNO, "Note: Cannot open TUN/TAP dev %s", node);
-	  goto linux_2_2_fallback;
-	}
-
-      /*
-       * Process --tun-ipv6
-       */
-      CLEAR (ifr);
-      if (!tt->ipv6)
-	ifr.ifr_flags = IFF_NO_PI;
-
-#if defined(IFF_ONE_QUEUE) && defined(SIOCSIFTXQLEN)
-      ifr.ifr_flags |= IFF_ONE_QUEUE;
-#endif
-
-      /*
-       * Figure out if tun or tap device
-       */
-      if (tt->type == DEV_TYPE_TUN)
-	{
-	  ifr.ifr_flags |= IFF_TUN;
-	}
-      else if (tt->type == DEV_TYPE_TAP)
-	{
-	  ifr.ifr_flags |= IFF_TAP;
-	}
-      else
-	{
-	  msg (M_FATAL, "I don't recognize device %s as a tun or tap device",
-	       dev);
-	}
-
-      /*
-       * Set an explicit name, if --dev is not tun or tap
-       */
-      if (strcmp(dev, "tun") && strcmp(dev, "tap"))
-	strncpynt (ifr.ifr_name, dev, IFNAMSIZ);
-
-      /*
-       * Use special ioctl that configures tun/tap device with the parms
-       * we set in ifr
-       */
-      if (ioctl (tt->fd, TUNSETIFF, (void *) &ifr) < 0)
-	{
-	  msg (M_WARN | M_ERRNO, "Note: Cannot ioctl TUNSETIFF %s", dev);
-	  goto linux_2_2_fallback;
-	}
-
-      msg (M_INFO, "TUN/TAP device %s opened", ifr.ifr_name);
-
-      /*
-       * Try making the TX send queue bigger
-       */
-#if defined(IFF_ONE_QUEUE) && defined(SIOCSIFTXQLEN)
-      {
-	struct ifreq netifr;
-	int ctl_fd;
-
-	if ((ctl_fd = socket (AF_INET, SOCK_DGRAM, 0)) >= 0)
-	  {
-	    CLEAR (netifr);
-	    strncpynt (netifr.ifr_name, ifr.ifr_name, IFNAMSIZ);
-	    netifr.ifr_qlen = tt->options.txqueuelen;
-	    if (ioctl (ctl_fd, SIOCSIFTXQLEN, (void *) &netifr) >= 0)
-	      msg (D_OSBUF, "TUN/TAP TX queue length set to %d", tt->options.txqueuelen);
-	    else
-	      msg (M_WARN | M_ERRNO, "Note: Cannot set tx queue length on %s", ifr.ifr_name);
-	    close (ctl_fd);
-	  }
-	else
-	  {
-	    msg (M_WARN | M_ERRNO, "Note: Cannot open control socket on %s", ifr.ifr_name);
-	  }
-      }
-#endif
-
-      set_nonblock (tt->fd);
-      set_cloexec (tt->fd);
-      tt->actual_name = string_alloc (ifr.ifr_name, NULL);
-    }
-  return;
-
- linux_2_2_fallback:
-  msg (M_INFO, "Note: Attempting fallback to kernel 2.2 TUN/TAP interface");
-  if (tt->fd >= 0)
-    {
-      close (tt->fd);
-      tt->fd = -1;
-    }
-  open_tun_generic (dev, dev_type, dev_node, ipv6, false, true, tt);
-}
-
-#else
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  ASSERT (0);
-}
-
-#endif
-
-#else
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  open_tun_generic (dev, dev_type, dev_node, ipv6, false, true, tt);
-}
-
-#endif /* HAVE_LINUX_IF_TUN_H */
-
-#ifdef TUNSETPERSIST
-
-void
-tuncfg (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, int persist_mode)
-{
-  struct tuntap *tt;
-
-  ALLOC_OBJ (tt, struct tuntap);
-  clear_tuntap (tt);
-  tt->type = dev_type_enum (dev, dev_type);
-  open_tun (dev, dev_type, dev_node, ipv6, tt);
-  if (ioctl (tt->fd, TUNSETPERSIST, persist_mode) < 0)
-    msg (M_ERR, "Cannot ioctl TUNSETPERSIST(%d) %s", persist_mode, dev);
-  close_tun (tt);
-  msg (M_INFO, "Persist state set to: %s", (persist_mode ? "ON" : "OFF"));
-}
-
-#endif /* TUNSETPERSIST */
-
-void
-close_tun (struct tuntap *tt)
-{
-  if (tt)
-    {
-      close_tun_generic (tt);
-      free (tt);
-    }
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-#if LINUX_IPV6
-  if (tt->ipv6)
-    {
-      struct tun_pi pi;
-      struct iphdr *iph;
-      struct iovec vect[2];
-      int ret;
-
-      iph = (struct iphdr *)buf;
-
-      pi.flags = 0;
-
-      if(iph->version == 6)
-	pi.proto = htons(ETH_P_IPV6);
-      else
-	pi.proto = htons(ETH_P_IP);
-
-      vect[0].iov_len = sizeof(pi);
-      vect[0].iov_base = &pi;
-      vect[1].iov_len = len;
-      vect[1].iov_base = buf;
-
-      ret = writev(tt->fd, vect, 2);
-      return(ret - sizeof(pi));
-    }
-  else
-#endif
-    return write (tt->fd, buf, len);
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-#if LINUX_IPV6
-  if (tt->ipv6)
-    {
-      struct iovec vect[2];
-      struct tun_pi pi;
-      int ret;
-
-      vect[0].iov_len = sizeof(pi);
-      vect[0].iov_base = &pi;
-      vect[1].iov_len = len;
-      vect[1].iov_base = buf;
-
-      ret = readv(tt->fd, vect, 2);
-      return(ret - sizeof(pi));
-    }
-  else
-#endif
-    return read (tt->fd, buf, len);
-}
-
-#elif defined(TARGET_SOLARIS)
-
-#ifndef TUNNEWPPA
-#error I need the symbol TUNNEWPPA from net/if_tun.h
-#endif
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  int if_fd, muxid, ppa = -1;
-  struct ifreq ifr;
-  const char *ptr;
-  const char *ip_node;
-  const char *dev_tuntap_type;
-  int link_type;
-  bool is_tun;
-
-  ipv6_support (ipv6, false, tt);
-
-  if (tt->type == DEV_TYPE_NULL)
-    {
-      open_null (tt);
-      return;
-    }
-
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      ip_node = "/dev/udp";
-      if (!dev_node)
-	dev_node = "/dev/tun";
-      dev_tuntap_type = "tun";
-      link_type = I_PLINK;
-      is_tun = true;
-    }
-  else if (tt->type == DEV_TYPE_TAP)
-    {
-      ip_node = "/dev/ip";
-      if (!dev_node)
-	dev_node = "/dev/tap";
-      dev_tuntap_type = "tap";
-      link_type = I_PLINK; /* was: I_LINK */
-      is_tun = false;
-    }
-  else
-    {
-      msg (M_FATAL, "I don't recognize device %s as a tun or tap device",
-	   dev);
-    }
-  
-  /* get unit number */
-  if (*dev)
-    {
-      ptr = dev;
-      while (*ptr && !isdigit ((int) *ptr))
-	ptr++;
-      ppa = atoi (ptr);
-    }
-
-  if ((tt->ip_fd = open (ip_node, O_RDWR, 0)) < 0)
-    msg (M_ERR, "Can't open %s", ip_node);
-
-  if ((tt->fd = open (dev_node, O_RDWR, 0)) < 0)
-    msg (M_ERR, "Can't open %s", dev_node);
-
-  /* Assign a new PPA and get its unit number. */
-  if ((ppa = ioctl (tt->fd, TUNNEWPPA, ppa)) < 0)
-    msg (M_ERR, "Can't assign new interface");
-
-  if ((if_fd = open (dev_node, O_RDWR, 0)) < 0)
-    msg (M_ERR, "Can't open %s (2)", dev_node);
-
-  if (ioctl (if_fd, I_PUSH, "ip") < 0)
-    msg (M_ERR, "Can't push IP module");
-
-  /* Assign ppa according to the unit number returned by tun device */
-  if (ioctl (if_fd, IF_UNITSEL, (char *) &ppa) < 0)
-    msg (M_ERR, "Can't set PPA %d", ppa);
-
-  if ((muxid = ioctl (tt->ip_fd, link_type, if_fd)) < 0)
-    msg (M_ERR, "Can't link %s device to IP", dev_tuntap_type);
-
-  close (if_fd);
-
-  tt->actual_name = (char *) malloc (32);
-  check_malloc_return (tt->actual_name);
-
-  openvpn_snprintf (tt->actual_name, 32, "%s%d", dev_tuntap_type, ppa);
-
-  CLEAR (ifr);
-  strncpynt (ifr.ifr_name, tt->actual_name, sizeof (ifr.ifr_name));
-  ifr.ifr_ip_muxid = muxid;
-
-  if (ioctl (tt->ip_fd, SIOCSIFMUXID, &ifr) < 0)
-    {
-      ioctl (tt->ip_fd, I_PUNLINK, muxid);
-      msg (M_ERR, "Can't set multiplexor id");
-    }
-
-  set_nonblock (tt->fd);
-  set_cloexec (tt->fd);
-  set_cloexec (tt->ip_fd);
-
-  msg (M_INFO, "TUN/TAP device %s opened", tt->actual_name);
-}
-
-static void
-solaris_close_tun (struct tuntap *tt)
-{
-  if (tt)
-    {
-      if (tt->ip_fd >= 0)
-	{
-	  struct ifreq ifr;
-	  CLEAR (ifr);
-	  strncpynt (ifr.ifr_name, tt->actual_name, sizeof (ifr.ifr_name));
-
-	  if (ioctl (tt->ip_fd, SIOCGIFFLAGS, &ifr) < 0)
-	    msg (M_WARN | M_ERRNO, "Can't get iface flags");
-
-	  if (ioctl (tt->ip_fd, SIOCGIFMUXID, &ifr) < 0)
-	    msg (M_WARN | M_ERRNO, "Can't get multiplexor id");
-
-	  if (ioctl (tt->ip_fd, I_PUNLINK, ifr.ifr_ip_muxid) < 0)
-	    msg (M_WARN | M_ERRNO, "Can't unlink interface");
-
-	  close (tt->ip_fd);
-	  tt->ip_fd = -1;
-	}
-
-      if (tt->fd >= 0)
-	{
-	  close (tt->fd);
-	  tt->fd = -1;
-	}
-    }
-}
-
-/*
- * Close TUN device. 
- */
-void
-close_tun (struct tuntap *tt)
-{
-  if (tt)
-    {
-      solaris_close_tun (tt);
-
-      if (tt->actual_name)
-	free (tt->actual_name);
-      
-      clear_tuntap (tt);
-      free (tt);
-    }
-}
-
-static void
-solaris_error_close (struct tuntap *tt, const struct env_set *es, const char *actual)
-{
-  char command_line[256];
-
-  openvpn_snprintf (command_line, sizeof (command_line),
-		    IFCONFIG_PATH " %s unplumb",
-		    actual);
-
-  msg (M_INFO, "%s", command_line);
-  system_check (command_line, es, 0, "Solaris ifconfig unplumb failed");
-  close_tun (tt);
-  msg (M_FATAL, "Solaris ifconfig failed");
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  struct strbuf sbuf;
-  sbuf.len = len;
-  sbuf.buf = (char *)buf;
-  return putmsg (tt->fd, NULL, &sbuf, 0) >= 0 ? sbuf.len : -1;
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  struct strbuf sbuf;
-  int f = 0;
-
-  sbuf.maxlen = len;
-  sbuf.buf = (char *)buf;
-  return getmsg (tt->fd, NULL, &sbuf, &f) >= 0 ? sbuf.len : -1;
-}
-
-#elif defined(TARGET_OPENBSD)
-
-#if !defined(HAVE_READV) || !defined(HAVE_WRITEV)
-#error openbsd build requires readv & writev library functions
-#endif
-
-/*
- * OpenBSD has a slightly incompatible TUN device from
- * the rest of the world, in that it prepends a
- * uint32 to the beginning of the IP header
- * to designate the protocol (why not just
- * look at the version field in the IP header to
- * determine v4 or v6?).
- *
- * We strip off this field on reads and
- * put it back on writes.
- *
- * I have not tested TAP devices on OpenBSD,
- * but I have conditionalized the special
- * TUN handling code described above to
- * go away for TAP devices.
- */
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
-
-  /* Enable multicast on the interface */
-  if (tt->fd >= 0)
-    {
-      struct tuninfo info;
-
-      if (ioctl (tt->fd, TUNGIFINFO, &info) < 0) {
-	msg (M_WARN | M_ERRNO, "Can't get interface info: %s",
-	  strerror(errno));
-      }
-
-      info.flags |= IFF_MULTICAST;
-
-      if (ioctl (tt->fd, TUNSIFINFO, &info) < 0) {
-	msg (M_WARN | M_ERRNO, "Can't set interface info: %s",
-	  strerror(errno));
-      }
-    }
-}
-
-void
-close_tun (struct tuntap* tt)
-{
-  if (tt)
-    {
-      close_tun_generic (tt);
-      free (tt);
-    }
-}
-
-static inline int
-openbsd_modify_read_write_return (int len)
-{
- if (len > 0)
-    return len > sizeof (u_int32_t) ? len - sizeof (u_int32_t) : 0;
-  else
-    return len;
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      u_int32_t type;
-      struct iovec iv[2];
-      struct ip *iph;
-
-      iph = (struct ip *) buf;
-
-      if (tt->ipv6 && iph->ip_v == 6)
-	type = htonl (AF_INET6);
-      else 
-	type = htonl (AF_INET);
-
-      iv[0].iov_base = &type;
-      iv[0].iov_len = sizeof (type);
-      iv[1].iov_base = buf;
-      iv[1].iov_len = len;
-
-      return openbsd_modify_read_write_return (writev (tt->fd, iv, 2));
-    }
-  else
-    return write (tt->fd, buf, len);
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      u_int32_t type;
-      struct iovec iv[2];
-
-      iv[0].iov_base = &type;
-      iv[0].iov_len = sizeof (type);
-      iv[1].iov_base = buf;
-      iv[1].iov_len = len;
-
-      return openbsd_modify_read_write_return (readv (tt->fd, iv, 2));
-    }
-  else
-    return read (tt->fd, buf, len);
-}
-
-#elif defined(TARGET_NETBSD)
-
-/*
- * NetBSD does not support IPv6 on tun out of the box,
- * but there exists a patch. When this patch is applied,
- * only two things are left to openvpn:
- * 1. Activate multicasting (this has already been done
- *    before by the kernel, but we make sure that nobody
- *    has deactivated multicasting inbetween.
- * 2. Deactivate "link layer mode" (otherwise NetBSD 
- *    prepends the address family to the packet, and we
- *    would run into the same trouble as with OpenBSD.
- */
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-    open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
-    if (tt->fd >= 0)
-      {
-        int i = IFF_POINTOPOINT|IFF_MULTICAST;
-        ioctl (tt->fd, TUNSIFMODE, &i);  /* multicast on */
-        i = 0;
-        ioctl (tt->fd, TUNSLMODE, &i);   /* link layer mode off */
-      }
-}
-
-void
-close_tun (struct tuntap *tt)
-{
-  if (tt)
-    {
-      close_tun_generic (tt);
-      free (tt);
-    }
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-    return write (tt->fd, buf, len);
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-    return read (tt->fd, buf, len);
-}
-
-#elif defined(TARGET_FREEBSD)
-
-static inline int
-freebsd_modify_read_write_return (int len)
-{
-  if (len > 0)
-    return len > sizeof (u_int32_t) ? len - sizeof (u_int32_t) : 0;
-  else
-    return len;
-}
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
-
-  if (tt->fd >= 0)
-    {
-      int i = 0;
-
-      /* Disable extended modes */
-      ioctl (tt->fd, TUNSLMODE, &i);
-      i = 1;
-      ioctl (tt->fd, TUNSIFHEAD, &i);
-    }
-}
-
-void
-close_tun (struct tuntap *tt)
-{
-  if (tt)
-    {
-      close_tun_generic (tt);
-      free (tt);
-    }
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      u_int32_t type;
-      struct iovec iv[2];
-      struct ip *iph;
-
-      iph = (struct ip *) buf;
-
-      if (tt->ipv6 && iph->ip_v == 6)
-        type = htonl (AF_INET6);
-      else 
-        type = htonl (AF_INET);
-
-      iv[0].iov_base = (char *)&type;
-      iv[0].iov_len = sizeof (type);
-      iv[1].iov_base = buf;
-      iv[1].iov_len = len;
-
-      return freebsd_modify_read_write_return (writev (tt->fd, iv, 2));
-    }
-  else
-    return write (tt->fd, buf, len);
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      u_int32_t type;
-      struct iovec iv[2];
-
-      iv[0].iov_base = (char *)&type;
-      iv[0].iov_len = sizeof (type);
-      iv[1].iov_base = buf;
-      iv[1].iov_len = len;
-
-      return freebsd_modify_read_write_return (readv (tt->fd, iv, 2));
-    }
-  else
-    return read (tt->fd, buf, len);
-}
-
-#elif defined(WIN32)
-
-int
-tun_read_queue (struct tuntap *tt, int maxsize)
-{
-  if (tt->reads.iostate == IOSTATE_INITIAL)
-    {
-      DWORD len;
-      BOOL status;
-      int err;
-
-      /* reset buf to its initial state */
-      tt->reads.buf = tt->reads.buf_init;
-
-      len = maxsize ? maxsize : BLEN (&tt->reads.buf);
-      ASSERT (len <= BLEN (&tt->reads.buf));
-
-      /* the overlapped read will signal this event on I/O completion */
-      ASSERT (ResetEvent (tt->reads.overlapped.hEvent));
-
-      status = ReadFile(
-		      tt->hand,
-		      BPTR (&tt->reads.buf),
-		      len,
-		      &tt->reads.size,
-		      &tt->reads.overlapped
-		      );
-
-      if (status) /* operation completed immediately? */
-	{
-	  /* since we got an immediate return, we must signal the event object ourselves */
-	  ASSERT (SetEvent (tt->reads.overlapped.hEvent));
-
-	  tt->reads.iostate = IOSTATE_IMMEDIATE_RETURN;
-	  tt->reads.status = 0;
-
-	  dmsg (D_WIN32_IO, "WIN32 I/O: TAP Read immediate return [%d,%d]",
-	       (int) len,
-	       (int) tt->reads.size);	       
-	}
-      else
-	{
-	  err = GetLastError (); 
-	  if (err == ERROR_IO_PENDING) /* operation queued? */
-	    {
-	      tt->reads.iostate = IOSTATE_QUEUED;
-	      tt->reads.status = err;
-	      dmsg (D_WIN32_IO, "WIN32 I/O: TAP Read queued [%d]",
-		   (int) len);
-	    }
-	  else /* error occurred */
-	    {
-	      struct gc_arena gc = gc_new ();
-	      ASSERT (SetEvent (tt->reads.overlapped.hEvent));
-	      tt->reads.iostate = IOSTATE_IMMEDIATE_RETURN;
-	      tt->reads.status = err;
-	      dmsg (D_WIN32_IO, "WIN32 I/O: TAP Read error [%d] : %s",
-		   (int) len,
-		   strerror_win32 (status, &gc));
-	      gc_free (&gc);
-	    }
-	}
-    }
-  return tt->reads.iostate;
-}
-
-int
-tun_write_queue (struct tuntap *tt, struct buffer *buf)
-{
-  if (tt->writes.iostate == IOSTATE_INITIAL)
-    {
-      BOOL status;
-      int err;
- 
-      /* make a private copy of buf */
-      tt->writes.buf = tt->writes.buf_init;
-      tt->writes.buf.len = 0;
-      ASSERT (buf_copy (&tt->writes.buf, buf));
-
-      /* the overlapped write will signal this event on I/O completion */
-      ASSERT (ResetEvent (tt->writes.overlapped.hEvent));
-
-      status = WriteFile(
-			tt->hand,
-			BPTR (&tt->writes.buf),
-			BLEN (&tt->writes.buf),
-			&tt->writes.size,
-			&tt->writes.overlapped
-			);
-
-      if (status) /* operation completed immediately? */
-	{
-	  tt->writes.iostate = IOSTATE_IMMEDIATE_RETURN;
-
-	  /* since we got an immediate return, we must signal the event object ourselves */
-	  ASSERT (SetEvent (tt->writes.overlapped.hEvent));
-
-	  tt->writes.status = 0;
-
-	  dmsg (D_WIN32_IO, "WIN32 I/O: TAP Write immediate return [%d,%d]",
-	       BLEN (&tt->writes.buf),
-	       (int) tt->writes.size);	       
-	}
-      else
-	{
-	  err = GetLastError (); 
-	  if (err == ERROR_IO_PENDING) /* operation queued? */
-	    {
-	      tt->writes.iostate = IOSTATE_QUEUED;
-	      tt->writes.status = err;
-	      dmsg (D_WIN32_IO, "WIN32 I/O: TAP Write queued [%d]",
-		   BLEN (&tt->writes.buf));
-	    }
-	  else /* error occurred */
-	    {
-	      struct gc_arena gc = gc_new ();
-	      ASSERT (SetEvent (tt->writes.overlapped.hEvent));
-	      tt->writes.iostate = IOSTATE_IMMEDIATE_RETURN;
-	      tt->writes.status = err;
-	      dmsg (D_WIN32_IO, "WIN32 I/O: TAP Write error [%d] : %s",
-		   BLEN (&tt->writes.buf),
-		   strerror_win32 (err, &gc));
-	      gc_free (&gc);
-	    }
-	}
-    }
-  return tt->writes.iostate;
-}
-
-int
-tun_finalize (
-	      HANDLE h,
-	      struct overlapped_io *io,
-	      struct buffer *buf)
-{
-  int ret = -1;
-  BOOL status;
-
-  switch (io->iostate)
-    {
-    case IOSTATE_QUEUED:
-      status = GetOverlappedResult(
-				   h,
-				   &io->overlapped,
-				   &io->size,
-				   FALSE
-				   );
-      if (status)
-	{
-	  /* successful return for a queued operation */
-	  if (buf)
-	    *buf = io->buf;
-	  ret = io->size;
-	  io->iostate = IOSTATE_INITIAL;
-	  ASSERT (ResetEvent (io->overlapped.hEvent));
-	  dmsg (D_WIN32_IO, "WIN32 I/O: TAP Completion success [%d]", ret);
-	}
-      else
-	{
-	  /* error during a queued operation */
-	  ret = -1;
-	  if (GetLastError() != ERROR_IO_INCOMPLETE)
-	    {
-	      /* if no error (i.e. just not finished yet),
-		 then DON'T execute this code */
-	      io->iostate = IOSTATE_INITIAL;
-	      ASSERT (ResetEvent (io->overlapped.hEvent));
-	      msg (D_WIN32_IO | M_ERRNO, "WIN32 I/O: TAP Completion error");
-	    }
-	}
-      break;
-
-    case IOSTATE_IMMEDIATE_RETURN:
-      io->iostate = IOSTATE_INITIAL;
-      ASSERT (ResetEvent (io->overlapped.hEvent));
-      if (io->status)
-	{
-	  /* error return for a non-queued operation */
-	  SetLastError (io->status);
-	  ret = -1;
-	  msg (D_WIN32_IO | M_ERRNO, "WIN32 I/O: TAP Completion non-queued error");
-	}
-      else
-	{
-	  /* successful return for a non-queued operation */
-	  if (buf)
-	    *buf = io->buf;
-	  ret = io->size;
-	  dmsg (D_WIN32_IO, "WIN32 I/O: TAP Completion non-queued success [%d]", ret);
-	}
-      break;
-
-    case IOSTATE_INITIAL: /* were we called without proper queueing? */
-      SetLastError (ERROR_INVALID_FUNCTION);
-      ret = -1;
-      dmsg (D_WIN32_IO, "WIN32 I/O: TAP Completion BAD STATE");
-      break;
-
-    default:
-      ASSERT (0);
-    }
-
-  if (buf)
-    buf->len = ret;
-  return ret;
-}
-
-const struct tap_reg *
-get_tap_reg (struct gc_arena *gc)
-{
-  HKEY adapter_key;
-  LONG status;
-  DWORD len;
-  struct tap_reg *first = NULL;
-  struct tap_reg *last = NULL;
-  int i = 0;
-
-  status = RegOpenKeyEx(
-			HKEY_LOCAL_MACHINE,
-			ADAPTER_KEY,
-			0,
-			KEY_READ,
-			&adapter_key);
-
-  if (status != ERROR_SUCCESS)
-    msg (M_FATAL, "Error opening registry key: %s", ADAPTER_KEY);
-
-  while (true)
-    {
-      char enum_name[256];
-      char unit_string[256];
-      HKEY unit_key;
-      char component_id_string[] = "ComponentId";
-      char component_id[256];
-      char net_cfg_instance_id_string[] = "NetCfgInstanceId";
-      char net_cfg_instance_id[256];
-      DWORD data_type;
-
-      len = sizeof (enum_name);
-      status = RegEnumKeyEx(
-			    adapter_key,
-			    i,
-			    enum_name,
-			    &len,
-			    NULL,
-			    NULL,
-			    NULL,
-			    NULL);
-      if (status == ERROR_NO_MORE_ITEMS)
-	break;
-      else if (status != ERROR_SUCCESS)
-	msg (M_FATAL, "Error enumerating registry subkeys of key: %s",
-	     ADAPTER_KEY);
-
-      openvpn_snprintf (unit_string, sizeof(unit_string), "%s\\%s",
-			ADAPTER_KEY, enum_name);
-
-      status = RegOpenKeyEx(
-			    HKEY_LOCAL_MACHINE,
-			    unit_string,
-			    0,
-			    KEY_READ,
-			    &unit_key);
-
-      if (status != ERROR_SUCCESS)
-	dmsg (D_REGISTRY, "Error opening registry key: %s", unit_string);
-      else
-	{
-	  len = sizeof (component_id);
-	  status = RegQueryValueEx(
-				   unit_key,
-				   component_id_string,
-				   NULL,
-				   &data_type,
-				   component_id,
-				   &len);
-
-	  if (status != ERROR_SUCCESS || data_type != REG_SZ)
-	    dmsg (D_REGISTRY, "Error opening registry key: %s\\%s",
-		 unit_string, component_id_string);
-	  else
-	    {	      
-	      len = sizeof (net_cfg_instance_id);
-	      status = RegQueryValueEx(
-				       unit_key,
-				       net_cfg_instance_id_string,
-				       NULL,
-				       &data_type,
-				       net_cfg_instance_id,
-				       &len);
-
-	      if (status == ERROR_SUCCESS && data_type == REG_SZ)
-		{
-		  if (!strcmp (component_id, TAP_COMPONENT_ID))
-		    {
-		      struct tap_reg *reg;
-		      ALLOC_OBJ_CLEAR_GC (reg, struct tap_reg, gc);
-		      reg->guid = string_alloc (net_cfg_instance_id, gc);
-		      
-		      /* link into return list */
-		      if (!first)
-			first = reg;
-		      if (last)
-			last->next = reg;
-		      last = reg;
-		    }
-		}
-	    }
-	  RegCloseKey (unit_key);
-	}
-      ++i;
-    }
-
-  RegCloseKey (adapter_key);
-  return first;
-}
-
-const struct panel_reg *
-get_panel_reg (struct gc_arena *gc)
-{
-  LONG status;
-  HKEY network_connections_key;
-  DWORD len;
-  struct panel_reg *first = NULL;
-  struct panel_reg *last = NULL;
-  int i = 0;
-
-  status = RegOpenKeyEx(
-			HKEY_LOCAL_MACHINE,
-			NETWORK_CONNECTIONS_KEY,
-			0,
-			KEY_READ,
-			&network_connections_key);
-
-  if (status != ERROR_SUCCESS)
-    msg (M_FATAL, "Error opening registry key: %s", NETWORK_CONNECTIONS_KEY);
-
-  while (true)
-    {
-      char enum_name[256];
-      char connection_string[256];
-      HKEY connection_key;
-      char name_data[256];
-      DWORD name_type;
-      const char name_string[] = "Name";
-
-      len = sizeof (enum_name);
-      status = RegEnumKeyEx(
-			    network_connections_key,
-			    i,
-			    enum_name,
-			    &len,
-			    NULL,
-			    NULL,
-			    NULL,
-			    NULL);
-      if (status == ERROR_NO_MORE_ITEMS)
-	break;
-      else if (status != ERROR_SUCCESS)
-	msg (M_FATAL, "Error enumerating registry subkeys of key: %s",
-	     NETWORK_CONNECTIONS_KEY);
-
-      openvpn_snprintf (connection_string, sizeof(connection_string),
-			"%s\\%s\\Connection",
-			NETWORK_CONNECTIONS_KEY, enum_name);
-
-      status = RegOpenKeyEx(
-			    HKEY_LOCAL_MACHINE,
-			    connection_string,
-			    0,
-			    KEY_READ,
-			    &connection_key);
-
-      if (status != ERROR_SUCCESS)
-	dmsg (D_REGISTRY, "Error opening registry key: %s", connection_string);
-      else
-	{
-	  len = sizeof (name_data);
-	  status = RegQueryValueEx(
-				   connection_key,
-				   name_string,
-				   NULL,
-				   &name_type,
-				   name_data,
-				   &len);
-
-	  if (status != ERROR_SUCCESS || name_type != REG_SZ)
-	    dmsg (D_REGISTRY, "Error opening registry key: %s\\%s\\%s",
-		 NETWORK_CONNECTIONS_KEY, connection_string, name_string);
-	  else
-	    {
-	      struct panel_reg *reg;
-
-	      ALLOC_OBJ_CLEAR_GC (reg, struct panel_reg, gc);
-	      reg->name = string_alloc (name_data, gc);
-	      reg->guid = string_alloc (enum_name, gc);
-		      
-	      /* link into return list */
-	      if (!first)
-		first = reg;
-	      if (last)
-		last->next = reg;
-	      last = reg;
-	    }
-	  RegCloseKey (connection_key);
-	}
-      ++i;
-    }
-
-  RegCloseKey (network_connections_key);
-
-  return first;
-}
-
-/*
- * Check that two addresses are part of the same 255.255.255.252 subnet.
- */
-void
-verify_255_255_255_252 (in_addr_t local, in_addr_t remote)
-{
-  struct gc_arena gc = gc_new ();
-  const unsigned int mask = 3;
-  const char *err = NULL;
-
-  if (local == remote)
-    {
-      err = "must be different";
-      goto error;
-    }
-  if ((local & (~mask)) != (remote & (~mask)))
-    {
-      err = "must exist within the same 255.255.255.252 subnet.  This is a limitation of --dev tun when used with the TAP-WIN32 driver";
-      goto error;
-    }
-  if ((local & mask) == 0
-      || (local & mask) == 3
-      || (remote & mask) == 0
-      || (remote & mask) == 3)
-    {
-      err = "cannot use the first or last address within a given 255.255.255.252 subnet.  This is a limitation of --dev tun when used with the TAP-WIN32 driver";
-      goto error;
-    }
-
-  gc_free (&gc);
-  return;
-
- error:
-  msg (M_FATAL, "There is a problem in your selection of --ifconfig endpoints [local=%s, remote=%s].  The local and remote VPN endpoints %s.  Try '" PACKAGE " --show-valid-subnets' option for more info.",
-       print_in_addr_t (local, 0, &gc),
-       print_in_addr_t (remote, 0, &gc),
-       err);
-  gc_free (&gc);
-}
-
-void show_valid_win32_tun_subnets (void)
-{
-  int i;
-  int col = 0;
-
-  printf ("On Windows, point-to-point IP support (i.e. --dev tun)\n");
-  printf ("is emulated by the TAP-Win32 driver.  The major limitation\n");
-  printf ("imposed by this approach is that the --ifconfig local and\n");
-  printf ("remote endpoints must be part of the same 255.255.255.252\n");
-  printf ("subnet.  The following list shows examples of endpoint\n");
-  printf ("pairs which satisfy this requirement.  Only the final\n");
-  printf ("component of the IP address pairs is at issue.\n\n");
-  printf ("As an example, the following option would be correct:\n");
-  printf ("    --ifconfig 10.7.0.5 10.7.0.6 (on host A)\n");
-  printf ("    --ifconfig 10.7.0.6 10.7.0.5 (on host B)\n");
-  printf ("because [5,6] is part of the below list.\n\n");
-
-  for (i = 0; i < 256; i += 4)
-    {
-      printf("[%3d,%3d] ", i+1, i+2);
-      if (++col > 4)
-	{
-	  col = 0;
-	  printf ("\n");
-	}
-    }
-  if (col)
-    printf ("\n");
-}
-
-void
-show_tap_win32_adapters (int msglev, int warnlev)
-{
-  struct gc_arena gc = gc_new ();
-
-  bool warn_panel_null = false;
-  bool warn_panel_dup = false;
-  bool warn_tap_dup = false;
-
-  int links;
-
-  const struct tap_reg *tr;
-  const struct tap_reg *tr1;
-  const struct panel_reg *pr;
-
-  const struct tap_reg *tap_reg = get_tap_reg (&gc);
-  const struct panel_reg *panel_reg = get_panel_reg (&gc);
-
-  msg (msglev, "Available TAP-WIN32 adapters [name, GUID]:");
-
-  /* loop through each TAP-Win32 adapter registry entry */
-  for (tr = tap_reg; tr != NULL; tr = tr->next)
-    {
-      links = 0;
-
-      /* loop through each network connections entry in the control panel */
-      for (pr = panel_reg; pr != NULL; pr = pr->next)
-	{
-	  if (!strcmp (tr->guid, pr->guid))
-	    {
-	      msg (msglev, "'%s' %s", pr->name, tr->guid);
-	      ++links;
-	    }
-	}
-
-      if (links > 1)
-	{
-	  warn_panel_dup = true;
-	}
-      else if (links == 0)
-	{
-	  /* a TAP adapter exists without a link from the network
-	     connections control panel */
-	  warn_panel_null = true;
-	  msg (msglev, "[NULL] %s", tr->guid);
-	}
-    }
-
-  /* check for TAP-Win32 adapter duplicated GUIDs */
-  for (tr = tap_reg; tr != NULL; tr = tr->next)
-    {
-      for (tr1 = tap_reg; tr1 != NULL; tr1 = tr1->next)
-	{
-	  if (tr != tr1 && !strcmp (tr->guid, tr1->guid))
-	    warn_tap_dup = true;
-	}
-    }
-
-  /* warn on registry inconsistencies */
-  if (warn_tap_dup)
-    msg (warnlev, "WARNING: Some TAP-Win32 adapters have duplicate GUIDs");
-
-  if (warn_panel_dup)
-    msg (warnlev, "WARNING: Some TAP-Win32 adapters have duplicate links from the Network Connections control panel");
-
-  if (warn_panel_null)
-    msg (warnlev, "WARNING: Some TAP-Win32 adapters have no link from the Network Connections control panel");
-
-  gc_free (&gc);
-}
-
-/*
- * Confirm that GUID is a TAP-Win32 adapter.
- */
-static bool
-is_tap_win32 (const char *guid, const struct tap_reg *tap_reg)
-{
-  const struct tap_reg *tr;
-
-  for (tr = tap_reg; tr != NULL; tr = tr->next)
-    {
-      if (guid && !strcmp (tr->guid, guid))
-	return true;
-    }
-
-  return false;
-}
-
-static const char *
-guid_to_name (const char *guid, const struct panel_reg *panel_reg)
-{
-  const struct panel_reg *pr;
-
-  for (pr = panel_reg; pr != NULL; pr = pr->next)
-    {
-      if (guid && !strcmp (pr->guid, guid))
-	return pr->name;
-    }
-
-  return NULL;
-}
-
-static const char *
-name_to_guid (const char *name, const struct tap_reg *tap_reg, const struct panel_reg *panel_reg)
-{
-  const struct panel_reg *pr;
-
-  for (pr = panel_reg; pr != NULL; pr = pr->next)
-    {
-      if (name && !strcmp (pr->name, name) && is_tap_win32 (pr->guid, tap_reg))
-	return pr->guid;
-    }
-
-  return NULL;
-}
-
-static void
-at_least_one_tap_win32 (const struct tap_reg *tap_reg)
-{
-  if (!tap_reg)
-    msg (M_FATAL, "There are no TAP-Win32 adapters on this system.  You should be able to create a TAP-Win32 adapter by going to Start -> All Programs -> " PACKAGE_NAME " -> Add a new TAP-Win32 virtual ethernet adapter.");
-}
-
-/*
- * Get an adapter GUID and optional actual_name from the 
- * registry for the TAP device # = device_number.
- */
-static const char *
-get_unspecified_device_guid (const int device_number,
-		             char *actual_name,
-		             int actual_name_size,
-			     const struct tap_reg *tap_reg_src,
-			     const struct panel_reg *panel_reg_src,
-		             struct gc_arena *gc)
-{
-  const struct tap_reg *tap_reg = tap_reg_src;
-  struct buffer ret = clear_buf ();
-  struct buffer actual = clear_buf ();
-  int i;
-
-  ASSERT (device_number >= 0);
-
-  /* Make sure we have at least one TAP adapter */
-  if (!tap_reg)
-    return NULL;
-
-  /* The actual_name output buffer may be NULL */
-  if (actual_name)
-    {
-      ASSERT (actual_name_size > 0);
-      buf_set_write (&actual, actual_name, actual_name_size);
-    }
-
-  /* Move on to specified device number */
-  for (i = 0; i < device_number; i++)
-    {
-      tap_reg = tap_reg->next;
-      if (!tap_reg)
-	return NULL;
-    }
-
-  /* Save Network Panel name (if exists) in actual_name */
-  if (actual_name)
-    {
-      const char *act = guid_to_name (tap_reg->guid, panel_reg_src);
-      if (act)
-	buf_printf (&actual, "%s", act);
-      else
-	buf_printf (&actual, "NULL");
-    }
-
-  /* Save GUID for return value */
-  ret = alloc_buf_gc (256, gc);
-  buf_printf (&ret, "%s", tap_reg->guid);
-  return BSTR (&ret);
-}
-
-/*
- * Lookup a --dev-node adapter name in the registry
- * returning the GUID and optional actual_name.
- */
-static const char *
-get_device_guid (const char *name,
-		 char *actual_name,
-		 int actual_name_size,
-		 const struct tap_reg *tap_reg,
-		 const struct panel_reg *panel_reg,
-		 struct gc_arena *gc)
-{
-  struct buffer ret = alloc_buf_gc (256, gc);
-  struct buffer actual = clear_buf ();
-
-  /* Make sure we have at least one TAP adapter */
-  if (!tap_reg)
-    return NULL;
-
-  /* The actual_name output buffer may be NULL */
-  if (actual_name)
-    {
-      ASSERT (actual_name_size > 0);
-      buf_set_write (&actual, actual_name, actual_name_size);
-    }
-
-  /* Check if GUID was explicitly specified as --dev-node parameter */
-  if (is_tap_win32 (name, tap_reg))
-    {
-      const char *act = guid_to_name (name, panel_reg);
-      buf_printf (&ret, "%s", name);
-      if (act)
-	buf_printf (&actual, "%s", act);
-      else
-	buf_printf (&actual, "NULL");
-      return BSTR (&ret);
-    }
-
-  /* Lookup TAP adapter in network connections list */
-  {
-    const char *guid = name_to_guid (name, tap_reg, panel_reg);
-    if (guid)
-      {
-	buf_printf (&actual, "%s", name);
-	buf_printf (&ret, "%s", guid);
-	return BSTR (&ret);
-      }
-  }
-
-  return NULL;
-}
-
-/*
- * Return a TAP name for netsh commands.
- */
-const char *
-get_netsh_id (const char *dev_node, struct gc_arena *gc)
-{
-  const struct tap_reg *tap_reg = get_tap_reg (gc);
-  const struct panel_reg *panel_reg = get_panel_reg (gc);
-  struct buffer actual = alloc_buf_gc (256, gc);
-  const char *guid;
-
-  at_least_one_tap_win32 (tap_reg);
-
-  if (dev_node)
-    {
-      guid = get_device_guid (dev_node, BPTR (&actual), BCAP (&actual), tap_reg, panel_reg, gc);
-    }
-  else
-    {
-      guid = get_unspecified_device_guid (0, BPTR (&actual), BCAP (&actual), tap_reg, panel_reg, gc);
-
-      if (get_unspecified_device_guid (1, NULL, 0, tap_reg, panel_reg, gc)) /* ambiguous if more than one TAP-Win32 adapter */
-	guid = NULL;
-    }
-
-  if (!guid)
-    return "NULL";         /* not found */
-  else if (strcmp (BPTR (&actual), "NULL"))
-    return BPTR (&actual); /* control panel name */
-  else
-    return guid;           /* no control panel name, return GUID instead */
-}
-
-/*
- * Get adapter info list
- */
-const IP_ADAPTER_INFO *
-get_adapter_info_list (struct gc_arena *gc)
-{
-  ULONG size = 0;
-  IP_ADAPTER_INFO *pi = NULL;
-  DWORD status;
-
-  if ((status = GetAdaptersInfo (NULL, &size)) != ERROR_BUFFER_OVERFLOW)
-    {
-      msg (M_INFO, "GetAdaptersInfo #1 failed (status=%u) : %s",
-	   (unsigned int)status,
-	   strerror_win32 (status, gc));
-    }
-  else
-    {
-      pi = (PIP_ADAPTER_INFO) gc_malloc (size, false, gc);
-      if ((status = GetAdaptersInfo (pi, &size)) == NO_ERROR)
-	return pi;
-      else
-	{
-	  msg (M_INFO, "GetAdaptersInfo #2 failed (status=%u) : %s",
-	       (unsigned int)status,
-	       strerror_win32 (status, gc));
-	}
-    }
-  return pi;
-}
-
-static const IP_INTERFACE_INFO *
-get_interface_info_list (struct gc_arena *gc)
-{
-  ULONG size = 0;
-  IP_INTERFACE_INFO *ii = NULL;
-  DWORD status;
-
-  if ((status = GetInterfaceInfo (NULL, &size)) != ERROR_INSUFFICIENT_BUFFER)
-    {
-      msg (M_INFO, "GetInterfaceInfo #1 failed (status=%u) : %s",
-	   (unsigned int)status,
-	   strerror_win32 (status, gc));
-    }
-  else
-    {
-      ii = (PIP_INTERFACE_INFO) gc_malloc (size, false, gc);
-      if ((status = GetInterfaceInfo (ii, &size)) == NO_ERROR)
-	return ii;
-      else
-	{
-	  msg (M_INFO, "GetInterfaceInfo #2 failed (status=%u) : %s",
-	       (unsigned int)status,
-	       strerror_win32 (status, gc));
-	}
-    }
-  return ii;
-}
-
-static const IP_ADAPTER_INDEX_MAP *
-get_interface_info (DWORD index, struct gc_arena *gc)
-{
-  const IP_INTERFACE_INFO *list = get_interface_info_list (gc);
-  if (list)
-    {
-      int i;
-      for (i = 0; i < list->NumAdapters; ++i)
-	{
-	  const IP_ADAPTER_INDEX_MAP *inter = &list->Adapter[i];
-	  if (index == inter->Index)
-	    return inter;
-	}
-    }
-  return NULL;
-}
-
-/*
- * Given an adapter index, return a pointer to the
- * IP_ADAPTER_INFO structure for that adapter.
- */
-
-static const IP_ADAPTER_INFO *
-get_adapter (const IP_ADAPTER_INFO *ai, DWORD index)
-{
-  if (ai && index != (DWORD)~0)
-    {
-      const IP_ADAPTER_INFO *a;
-
-      /* find index in the linked list */
-      for (a = ai; a != NULL; a = a->Next)
-	{
-	  if (a->Index == index)
-	    return a;
-	}
-    }
-  return NULL;
-}
-
-static const IP_ADAPTER_INFO *
-get_adapter_info (DWORD index, struct gc_arena *gc)
-{
-  return get_adapter (get_adapter_info_list (gc), index);
-}
-
-static int
-get_adapter_n_ip_netmask (const IP_ADAPTER_INFO *ai)
-{
-  if (ai)
-    {
-      int n = 0;
-      const IP_ADDR_STRING *ip = &ai->IpAddressList;
-
-      while (ip)
-	{
-	  ++n;
-	  ip = ip->Next;
-	}
-      return n;
-    }
-  else
-    return 0;
-}
-
-static bool
-get_adapter_ip_netmask (const IP_ADAPTER_INFO *ai, const int n, in_addr_t *ip, in_addr_t *netmask)
-{
-  bool ret = false;
-  *ip = 0;
-  *netmask = 0;
-
-  if (ai)
-    {
-      const IP_ADDR_STRING *iplist = &ai->IpAddressList;
-      int i = 0;
-
-      while (iplist)
-	{
-	  if (i == n)
-	    break;
-	  ++i;
-	  iplist = iplist->Next;
-	}
-
-      if (iplist)
-	{
-	  const unsigned int getaddr_flags = GETADDR_HOST_ORDER;
-	  const char *ip_str = iplist->IpAddress.String;
-	  const char *netmask_str = iplist->IpMask.String;
-	  bool succeed1 = false;
-	  bool succeed2 = false;
-
-	  if (ip_str && netmask_str && strlen (ip_str) && strlen (netmask_str))
-	    {
-	      *ip = getaddr (getaddr_flags, ip_str, 0, &succeed1, NULL);
-	      *netmask = getaddr (getaddr_flags, netmask_str, 0, &succeed2, NULL);
-	      ret = (succeed1 == true && succeed2 == true);
-	    }
-	}
-    }
-
-  return ret;
-}
-
-const IP_ADAPTER_INFO *
-get_tun_adapter (const struct tuntap *tt, const IP_ADAPTER_INFO *list)
-{
-  if (list && tt)
-    return get_adapter (list, tt->adapter_index);
-  else
-    return NULL;
-}
-
-bool
-is_adapter_up (const struct tuntap *tt, const IP_ADAPTER_INFO *list)
-{
-  int i;
-  bool ret = false;
-
-  const IP_ADAPTER_INFO *ai = get_tun_adapter (tt, list);
-
-  if (ai)
-    {
-      const int n = get_adapter_n_ip_netmask (ai);
-
-      /* loop once for every IP/netmask assigned to adapter */
-      for (i = 0; i < n; ++i)
-	{
-	  in_addr_t ip, netmask;
-	  if (get_adapter_ip_netmask (ai, i, &ip, &netmask))
-	    {
-	      if (tt->local && tt->adapter_netmask)
-		{
-		  /* wait for our --ifconfig parms to match the actual adapter parms */
-		  if (tt->local == ip && tt->adapter_netmask == netmask)
-		    ret = true;
-		}
-	      else
-		{
-		  /* --ifconfig was not defined, maybe using a real DHCP server */
-		  if (ip && netmask)
-		    ret = true;
-		}
-	    }
-	}
-    }
-  else
-    ret = true; /* this can occur when TAP adapter is bridged */
-
-  return ret;
-}
-
-bool
-is_ip_in_adapter_subnet (const IP_ADAPTER_INFO *ai, const in_addr_t ip, in_addr_t *highest_netmask)
-{
-  int i;
-  bool ret = false;
-
-  if (highest_netmask)
-    *highest_netmask = 0;
-
-  if (ai)
-    {
-      const int n = get_adapter_n_ip_netmask (ai);
-      for (i = 0; i < n; ++i)
-	{
-	  in_addr_t adapter_ip, adapter_netmask;
-	  if (get_adapter_ip_netmask (ai, i, &adapter_ip, &adapter_netmask))
-	    {
-	      if (adapter_ip && adapter_netmask && (ip & adapter_netmask) == (adapter_ip & adapter_netmask))
-		{
-		  if (highest_netmask && adapter_netmask > *highest_netmask)
-		    *highest_netmask = adapter_netmask;
-		  ret = true;
-		}
-	    }
-	}
-    }
-  return ret;
-}
-
-DWORD
-adapter_index_of_ip (const IP_ADAPTER_INFO *list, const in_addr_t ip, int *count)
-{
-  struct gc_arena gc = gc_new ();
-  DWORD ret = ~0;
-  in_addr_t highest_netmask = 0;
-  bool first = true;
-
-  if (count)
-    *count = 0;
-
-  while (list)
-    {
-      in_addr_t hn;
-
-      if (is_ip_in_adapter_subnet (list, ip, &hn))
-	{
-	  if (first || hn > highest_netmask)
-	    {
-	      highest_netmask = hn;
-	      if (count)
-		*count = 1;
-	      ret = list->Index;
-	      first = false;
-	    }
-	  else if (hn == highest_netmask)
-	    {
-	      if (count)
-		++*count;
-	    }
-	}
-      list = list->Next;
-    }
-
-  dmsg (D_ROUTE_DEBUG, "DEBUG: IP Locate: ip=%s nm=%s index=%d count=%d",
-       print_in_addr_t (ip, 0, &gc),
-       print_in_addr_t (highest_netmask, 0, &gc),
-       (int)ret,
-       count ? *count : -1);
-
-  if (ret == ~0 && count)
-    *count = 0;
-
-  gc_free (&gc);
-  return ret;
-}
-
-/*
- * Given an adapter index, return true if the adapter
- * is DHCP disabled.
- */
-static bool
-dhcp_disabled (DWORD index)
-{
-  struct gc_arena gc = gc_new ();
-  const IP_ADAPTER_INFO *ai = get_adapter_info (index, &gc);
-  bool ret = false;
-
-  if (ai && !ai->DhcpEnabled)
-    ret = true;
-
-  gc_free (&gc);
-  return ret;
-}
-
-/*
- * Delete all temporary address/netmask pairs which were added
- * to adapter (given by index) by previous calls to AddIPAddress.
- */
-static void
-delete_temp_addresses (DWORD index)
-{
-  struct gc_arena gc = gc_new ();
-  const IP_ADAPTER_INFO *a = get_adapter_info (index, &gc);
-
-  if (a)
-    {
-      const IP_ADDR_STRING *ip = &a->IpAddressList;
-      while (ip)
-	{
-	  DWORD status;
-	  const DWORD context = ip->Context;
-
-	  if ((status = DeleteIPAddress ((ULONG) context)) == NO_ERROR)
-	    {
-	      msg (M_INFO, "Successfully deleted previously set dynamic IP/netmask: %s/%s",
-		   ip->IpAddress.String,
-		   ip->IpMask.String);
-	    }
-	  else
-	    {
-	      const char *empty = "0.0.0.0";
-	      if (strcmp (ip->IpAddress.String, empty)
-		  || strcmp (ip->IpMask.String, empty))
-		msg (M_INFO, "NOTE: could not delete previously set dynamic IP/netmask: %s/%s (status=%u)",
-		     ip->IpAddress.String,
-		     ip->IpMask.String,
-		     (unsigned int)status);
-	    }
-	  ip = ip->Next;
-	}
-    }
-  gc_free (&gc);
-}
-
-/*
- * Get interface index for use with IP Helper API functions.
- */
-static DWORD
-get_interface_index (const char *guid)
-{
-  struct gc_arena gc = gc_new ();
-  ULONG index;
-  DWORD status;
-  wchar_t wbuf[256];
-  snwprintf (wbuf, SIZE (wbuf), L"\\DEVICE\\TCPIP_%S", guid);
-  wbuf [SIZE(wbuf) - 1] = 0;
-  if ((status = GetAdapterIndex (wbuf, &index)) != NO_ERROR)
-    {
-      msg (M_INFO, "NOTE: could not get adapter index for %S, status=%u : %s",
-	   wbuf,
-	   (unsigned int)status,
-	   strerror_win32 (status, &gc));
-      gc_free (&gc);
-      return (DWORD)~0;
-    }
-  else
-    {
-      gc_free (&gc);
-      return index;
-    }
-}
-
-/*
- * Return a string representing a PIP_ADDR_STRING
- */
-static const char *
-format_ip_addr_string (const IP_ADDR_STRING *ip, struct gc_arena *gc)
-{
-  struct buffer out = alloc_buf_gc (256, gc);
-  while (ip)
-    {
-      buf_printf (&out, "%s", ip->IpAddress.String);
-      if (strlen (ip->IpMask.String))
-	{
-	  buf_printf (&out, "/");
-	  buf_printf (&out, "%s", ip->IpMask.String);
-	}
-      buf_printf (&out, " ");
-      ip = ip->Next;
-    }
-  return BSTR (&out);
-}
-
-/*
- * Show info for a single adapter
- */
-static void
-show_adapter (int msglev, const IP_ADAPTER_INFO *a, struct gc_arena *gc)
-{
-  msg (msglev, "%s", a->Description);
-  msg (msglev, "  Index = %d", (int)a->Index);
-  msg (msglev, "  GUID = %s", a->AdapterName);
-  msg (msglev, "  IP = %s", format_ip_addr_string (&a->IpAddressList, gc));
-  msg (msglev, "  MAC = %s", format_hex_ex (a->Address, a->AddressLength, 0, 1, ":", gc));
-  msg (msglev, "  GATEWAY = %s", format_ip_addr_string (&a->GatewayList, gc));
-  if (a->DhcpEnabled)
-    {
-      msg (msglev, "  DHCP SERV = %s", format_ip_addr_string (&a->DhcpServer, gc));
-      msg (msglev, "  DHCP LEASE OBTAINED = %s", time_string (a->LeaseObtained, 0, false, gc));
-      msg (msglev, "  DHCP LEASE EXPIRES  = %s", time_string (a->LeaseExpires, 0, false, gc));
-    }
-  if (a->HaveWins)
-    {
-      msg (msglev, "  PRI WINS = %s", format_ip_addr_string (&a->PrimaryWinsServer, gc));
-      msg (msglev, "  SEC WINS = %s", format_ip_addr_string (&a->SecondaryWinsServer, gc));
-    }
-}
-
-/*
- * Show current adapter list
- */
-void
-show_adapters (int msglev)
-{
-  struct gc_arena gc = gc_new ();
-  const IP_ADAPTER_INFO *ai = get_adapter_info_list (&gc);
-
-  msg (msglev, "SYSTEM ADAPTER LIST");
-  if (ai)
-    {
-      const IP_ADAPTER_INFO *a;
-
-      /* find index in the linked list */
-      for (a = ai; a != NULL; a = a->Next)
-	{
-	  show_adapter (msglev, a, &gc);
-	}
-    }
-  gc_free (&gc);
-}
-
-/*
- * DHCP release/renewal
- */
-
-bool
-dhcp_release (const struct tuntap *tt)
-{
-  struct gc_arena gc = gc_new ();
-  bool ret = false;
-  if (tt && tt->options.ip_win32_type == IPW32_SET_DHCP_MASQ && tt->adapter_index != ~0)
-    {
-      const IP_ADAPTER_INDEX_MAP *inter = get_interface_info (tt->adapter_index, &gc);
-      if (inter)
-	{
-	  DWORD status = IpReleaseAddress ((IP_ADAPTER_INDEX_MAP *)inter);
-	  if (status == NO_ERROR)
-	    {
-	      msg (D_TUNTAP_INFO, "TAP: DHCP address released");
-	      ret = true;
-	    }
-	  else
-	    msg (M_WARN, "NOTE: Release of DHCP-assigned IP address lease on TAP-Win32 adapter failed: %s (code=%u)",
-		 strerror_win32 (status, &gc),
-		 (unsigned int)status);
-	}
-    }
-  gc_free (&gc);
-  return ret;
-}
-
-bool
-dhcp_renew (const struct tuntap *tt)
-{
-  struct gc_arena gc = gc_new ();
-  bool ret = false;
-  if (tt && tt->options.ip_win32_type == IPW32_SET_DHCP_MASQ && tt->adapter_index != ~0)
-    {
-      const IP_ADAPTER_INDEX_MAP *inter = get_interface_info (tt->adapter_index, &gc);
-      if (inter)
-	{
-	  DWORD status = IpRenewAddress ((IP_ADAPTER_INDEX_MAP *)inter);
-	  if (status == NO_ERROR)
-	    {
-	      msg (D_TUNTAP_INFO, "TAP: DHCP address renewal succeeded");
-	      ret = true;
-	    }
-	  else
-	    msg (M_WARN, "WARNING: Failed to renew DHCP IP address lease on TAP-Win32 adapter: %s (code=%u)",
-		 strerror_win32 (status, &gc),
-		 (unsigned int)status);
-	}
-    }
-  gc_free (&gc);
-  return ret;
-}
-
-/*
- * Convert DHCP options from the command line / config file
- * into a raw DHCP-format options string.
- */
-
-static void
-write_dhcp_u8 (struct buffer *buf, const int type, const int data)
-{
-  if (!buf_safe (buf, 3))
-    msg (M_FATAL, "write_dhcp_u8: buffer overflow building DHCP options");
-  buf_write_u8 (buf, type);
-  buf_write_u8 (buf, 1);
-  buf_write_u8 (buf, data);
-}
-
-static void
-write_dhcp_u32_array (struct buffer *buf, const int type, const uint32_t *data, const unsigned int len)
-{
-  if (len > 0)
-    {
-      int i;
-      const int size = len * sizeof (uint32_t);
-
-      if (!buf_safe (buf, 2 + size))
-	msg (M_FATAL, "write_dhcp_u32_array: buffer overflow building DHCP options");
-      if (size < 1 || size > 255)
-	msg (M_FATAL, "write_dhcp_u32_array: size (%d) must be > 0 and <= 255", size);
-      buf_write_u8 (buf, type);
-      buf_write_u8 (buf, size);
-      for (i = 0; i < len; ++i)
-	buf_write_u32 (buf, data[i]);
-    }
-}
-
-static void
-write_dhcp_str (struct buffer *buf, const int type, const char *str)
-{
-  const int len = strlen (str);
-  if (!buf_safe (buf, 2 + len))
-    msg (M_FATAL, "write_dhcp_str: buffer overflow building DHCP options");
-  if (len < 1 || len > 255)
-    msg (M_FATAL, "write_dhcp_str: string '%s' must be > 0 bytes and <= 255 bytes", str);
-  buf_write_u8 (buf, type);
-  buf_write_u8 (buf, len);
-  buf_write (buf, str, len);
-}
-
-static void
-build_dhcp_options_string (struct buffer *buf, const struct tuntap_options *o)
-{
-  if (o->domain)
-    write_dhcp_str (buf, 15, o->domain);
-
-  if (o->netbios_scope)
-    write_dhcp_str (buf, 47, o->netbios_scope);
-
-  if (o->netbios_node_type)
-    write_dhcp_u8 (buf, 46, o->netbios_node_type);
-
-  write_dhcp_u32_array (buf, 6, (uint32_t*)o->dns, o->dns_len);
-  write_dhcp_u32_array (buf, 44, (uint32_t*)o->wins, o->wins_len);
-  write_dhcp_u32_array (buf, 42, (uint32_t*)o->ntp, o->ntp_len);
-  write_dhcp_u32_array (buf, 45, (uint32_t*)o->nbdd, o->nbdd_len);
-
-  /* the MS DHCP server option 'Disable Netbios-over-TCP/IP
-     is implemented as vendor option 001, value 002.
-     A value of 001 means 'leave NBT alone' which is the default */
-  if (o->disable_nbt)
-  {
-    buf_write_u8 (buf, 43);
-    buf_write_u8 (buf,  6);  /* total length field */
-    buf_write_u8 (buf,  0x001);
-    buf_write_u8 (buf,  4);  /* length of the vendor specified field */
-    buf_write_u32 (buf, 0x002);
-  }
-}
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  struct gc_arena gc = gc_new ();
-  char device_path[256];
-  const char *device_guid = NULL;
-  DWORD len;
-
-  /*netcmd_semaphore_lock ();*/
-
-  ipv6_support (ipv6, false, tt);
-
-  if (tt->type == DEV_TYPE_NULL)
-    {
-      open_null (tt);
-      gc_free (&gc);
-      return;
-    }
-  else if (tt->type == DEV_TYPE_TAP || tt->type == DEV_TYPE_TUN)
-    {
-      ;
-    }
-  else
-    {
-      msg (M_FATAL|M_NOPREFIX, "Unknown virtual device type: '%s'", dev);
-    }
-
-  /*
-   * Lookup the device name in the registry, using the --dev-node high level name.
-   */
-  {
-    const struct tap_reg *tap_reg = get_tap_reg (&gc);
-    const struct panel_reg *panel_reg = get_panel_reg (&gc);
-    char guid_buffer[256];
-
-    at_least_one_tap_win32 (tap_reg);
-
-    if (dev_node)
-      {
-        /* Get the device GUID for the device specified with --dev-node. */
-        device_guid = get_device_guid (dev_node, guid_buffer, sizeof (guid_buffer), tap_reg, panel_reg, &gc);
-
-	if (!device_guid)
-	    msg (M_FATAL, "TAP-Win32 adapter '%s' not found", dev_node);
-
-        /* Open Windows TAP-Win32 adapter */
-        openvpn_snprintf (device_path, sizeof(device_path), "%s%s%s",
-   		          USERMODEDEVICEDIR,
-		          device_guid,
-		          TAPSUFFIX);
-
-        tt->hand = CreateFile (
-			       device_path,
-			       GENERIC_READ | GENERIC_WRITE,
-			       0, /* was: FILE_SHARE_READ */
-			       0,
-			       OPEN_EXISTING,
-			       FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED,
-			       0
-			       );
-
-        if (tt->hand == INVALID_HANDLE_VALUE)
-          msg (M_ERR, "CreateFile failed on TAP device: %s", device_path);
-      }
-    else 
-      {
-        int device_number = 0;
-
-        /* Try opening all TAP devices until we find one available */
-        while (true)
-          {
-            device_guid = get_unspecified_device_guid (device_number, 
-						       guid_buffer, 
-						       sizeof (guid_buffer),
-						       tap_reg,
-						       panel_reg,
-						       &gc);
-
-	    if (!device_guid)
-	      msg (M_FATAL, "All TAP-Win32 adapters on this system are currently in use.");
-
-            /* Open Windows TAP-Win32 adapter */
-            openvpn_snprintf (device_path, sizeof(device_path), "%s%s%s",
-       		  	      USERMODEDEVICEDIR,
-			      device_guid,
-			      TAPSUFFIX);
-
-            tt->hand = CreateFile (
-			 	   device_path,
-				   GENERIC_READ | GENERIC_WRITE,
-				   0, /* was: FILE_SHARE_READ */
-				   0,
-				   OPEN_EXISTING,
-				   FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED,
-				   0
-				   );
-
-            if (tt->hand == INVALID_HANDLE_VALUE)
-              msg (D_TUNTAP_INFO, "CreateFile failed on TAP device: %s", device_path);
-            else
-              break;
-        
-            device_number++;
-          }
-      }
-
-    /* translate high-level device name into a device instance
-       GUID using the registry */
-    tt->actual_name = string_alloc (guid_buffer, NULL);
-  }
-
-  msg (M_INFO, "TAP-WIN32 device [%s] opened: %s", tt->actual_name, device_path);
-
-  /* get driver version info */
-  {
-    ULONG info[3];
-    CLEAR (info);
-    if (DeviceIoControl (tt->hand, TAP_IOCTL_GET_VERSION,
-			 &info, sizeof (info),
-			 &info, sizeof (info), &len, NULL))
-      {
-	msg (D_TUNTAP_INFO, "TAP-Win32 Driver Version %d.%d %s",
-	     (int) info[0],
-	     (int) info[1],
-	     (info[2] ? "(DEBUG)" : ""));
-
-      }
-    if ( !(info[0] > TAP_WIN32_MIN_MAJOR
-	   || (info[0] == TAP_WIN32_MIN_MAJOR && info[1] >= TAP_WIN32_MIN_MINOR)) )
-      msg (M_FATAL, "ERROR:  This version of " PACKAGE_NAME " requires a TAP-Win32 driver that is at least version %d.%d -- If you recently upgraded your " PACKAGE_NAME " distribution, a reboot is probably required at this point to get Windows to see the new driver.",
-	   TAP_WIN32_MIN_MAJOR,
-	   TAP_WIN32_MIN_MINOR);
-  }
-
-  /* get driver MTU */
-  {
-    ULONG mtu;
-    if (DeviceIoControl (tt->hand, TAP_IOCTL_GET_MTU,
-			 &mtu, sizeof (mtu),
-			 &mtu, sizeof (mtu), &len, NULL))
-      {
-	tt->post_open_mtu = (int) mtu;
-	msg (D_MTU_INFO, "TAP-Win32 MTU=%d", (int) mtu);
-      }
-  }
-
-  /* set point-to-point mode if TUN device */
-
-  if (tt->type == DEV_TYPE_TUN)
-    {
-      in_addr_t ep[2];
-      ep[0] = htonl (tt->local);
-      ep[1] = htonl (tt->remote_netmask);
-      if (!tt->did_ifconfig_setup)
-	{
-	  msg (M_FATAL, "ERROR: --dev tun also requires --ifconfig");
-	}
-      if (!DeviceIoControl (tt->hand, TAP_IOCTL_CONFIG_POINT_TO_POINT,
-			    ep, sizeof (ep),
-			    ep, sizeof (ep), &len, NULL))
-	msg (M_FATAL, "ERROR: The TAP-Win32 driver rejected a DeviceIoControl call to set Point-to-Point mode, which is required for --dev tun");
-    }
-
-  /* should we tell the TAP-Win32 driver to masquerade as a DHCP server as a means
-     of setting the adapter address? */
-  if (tt->did_ifconfig_setup && tt->options.ip_win32_type == IPW32_SET_DHCP_MASQ)
-    {
-      uint32_t ep[4];
-
-      /* We will answer DHCP requests with a reply to set IP/subnet to these values */
-      ep[0] = htonl (tt->local);
-      ep[1] = htonl (tt->adapter_netmask);
-
-      /* At what IP address should the DHCP server masquerade at? */
-      if (tt->type == DEV_TYPE_TUN)
-	{
-	  ep[2] = htonl (tt->remote_netmask);
-	  if (tt->options.dhcp_masq_custom_offset)
-	    msg (M_WARN, "WARNING: because you are using '--dev tun' mode, the '--ip-win32 dynamic [offset]' option is ignoring the offset parameter");
-	}
-      else
-	{
-	  in_addr_t dsa; /* DHCP server addr */
-
-	  ASSERT (tt->type == DEV_TYPE_TAP);
-
-	  if (tt->options.dhcp_masq_offset < 0)
-	    dsa = (tt->local | (~tt->adapter_netmask)) + tt->options.dhcp_masq_offset;
-	  else
-	    dsa = (tt->local & tt->adapter_netmask) + tt->options.dhcp_masq_offset;
-
-	  if (dsa == tt->local)
-	    msg (M_FATAL, "ERROR: There is a clash between the --ifconfig local address and the internal DHCP server address -- both are set to %s -- please use the --ip-win32 dynamic option to choose a different free address from the --ifconfig subnet for the internal DHCP server", print_in_addr_t (dsa, 0, &gc));
-
-	  if ((tt->local & tt->adapter_netmask) != (dsa & tt->adapter_netmask))
-	    msg (M_FATAL, "ERROR: --tap-win32 dynamic [offset] : offset is outside of --ifconfig subnet");
-
-	  ep[2] = htonl (dsa);
-	}
-
-      /* lease time in seconds */
-      ep[3] = (uint32_t) tt->options.dhcp_lease_time;
-
-      ASSERT (ep[3] > 0);
-
-      if (!DeviceIoControl (tt->hand, TAP_IOCTL_CONFIG_DHCP_MASQ,
-			    ep, sizeof (ep),
-			    ep, sizeof (ep), &len, NULL))
-	msg (M_FATAL, "ERROR: The TAP-Win32 driver rejected a DeviceIoControl call to set TAP_IOCTL_CONFIG_DHCP_MASQ mode");
-
-      msg (M_INFO, "Notified TAP-Win32 driver to set a DHCP IP/netmask of %s/%s on interface %s [DHCP-serv: %s, lease-time: %d]",
-	   print_in_addr_t (tt->local, 0, &gc),
-	   print_in_addr_t (tt->adapter_netmask, 0, &gc),
-	   device_guid,
-	   print_in_addr_t (ep[2], IA_NET_ORDER, &gc),
-	   ep[3]
-	   );
-
-      /* user-supplied DHCP options capability */
-      if (tt->options.dhcp_options)
-	{
-	  struct buffer buf = alloc_buf (256);
-	  build_dhcp_options_string (&buf, &tt->options);
-	  msg (D_DHCP_OPT, "DHCP option string: %s", format_hex (BPTR (&buf), BLEN (&buf), 0, &gc));
-	  if (!DeviceIoControl (tt->hand, TAP_IOCTL_CONFIG_DHCP_SET_OPT,
-				BPTR (&buf), BLEN (&buf),
-				BPTR (&buf), BLEN (&buf), &len, NULL))
-	    msg (M_FATAL, "ERROR: The TAP-Win32 driver rejected a TAP_IOCTL_CONFIG_DHCP_SET_OPT DeviceIoControl call");
-	  free_buf (&buf);
-	}
-    }
-
-  /* set driver media status to 'connected' */
-  {
-    ULONG status = TRUE;
-    if (!DeviceIoControl (tt->hand, TAP_IOCTL_SET_MEDIA_STATUS,
-			  &status, sizeof (status),
-			  &status, sizeof (status), &len, NULL))
-      msg (M_WARN, "WARNING: The TAP-Win32 driver rejected a TAP_IOCTL_SET_MEDIA_STATUS DeviceIoControl call.");
-  }
-
-  /* possible wait for adapter to come up */
-  {
-    int s = tt->options.tap_sleep;
-    if (s > 0)
-      {
-	msg (M_INFO, "Sleeping for %d seconds...", s);
-	openvpn_sleep (s);
-      }
-  }
-
-  /* possibly use IP Helper API to set IP address on adapter */
-  {
-    DWORD index = get_interface_index (device_guid);
-    tt->adapter_index = index;
-    
-    /* flush arp cache */
-    if (index != (DWORD)~0)
-      {
-	DWORD status;
-
-	if ((status = FlushIpNetTable (index)) == NO_ERROR)
-	  msg (M_INFO, "Successful ARP Flush on interface [%u] %s",
-	       (unsigned int)index,
-	       device_guid);
-	else
-	  msg (M_WARN, "NOTE: FlushIpNetTable failed on interface [%u] %s (status=%u) : %s",
-	       (unsigned int)index,
-	       device_guid,
-	       (unsigned int)status,
-	       strerror_win32 (status, &gc));
-      }
-
-    /*
-     * If the TAP-Win32 driver is masquerading as a DHCP server
-     * make sure the TCP/IP properties for the adapter are
-     * set correctly.
-     */
-    if (tt->did_ifconfig_setup && tt->options.ip_win32_type == IPW32_SET_DHCP_MASQ)
-      {
-	/* check dhcp enable status */
-	if (dhcp_disabled (index))
-	  msg (M_WARN, "WARNING: You have selected '--ip-win32 dynamic', which will not work unless the TAP-Win32 TCP/IP properties are set to 'Obtain an IP address automatically'");
-
-	/* force an explicit DHCP lease renewal on TAP adapter? */
-	if (tt->options.dhcp_pre_release)
-	  dhcp_release (tt);
-	if (tt->options.dhcp_renew)
-	  dhcp_renew (tt);
-      }
-
-    if (tt->did_ifconfig_setup && tt->options.ip_win32_type == IPW32_SET_IPAPI)
-      {
-	DWORD status;
-	const char *error_suffix = "I am having trouble using the Windows 'IP helper API' to automatically set the IP address -- consider using other --ip-win32 methods (not 'ipapi')";
-
-	/* couldn't get adapter index */
-	if (index == (DWORD)~0)
-	  {
-	    msg (M_FATAL, "ERROR: unable to get adapter index for interface %s -- %s",
-		 device_guid,
-		 error_suffix);
-	  }
-
-	/* check dhcp enable status */
-	if (dhcp_disabled (index))
-	  msg (M_WARN, "NOTE: You have selected (explicitly or by default) '--ip-win32 ipapi', which has a better chance of working correctly if the TAP-Win32 TCP/IP properties are set to 'Obtain an IP address automatically'");
-
-	/* delete previously added IP addresses which were not
-	   correctly deleted */
-	delete_temp_addresses (index);
-
-	/* add a new IP address */
-	if ((status = AddIPAddress (htonl(tt->local),
-				    htonl(tt->adapter_netmask),
-				    index,
-				    &tt->ipapi_context,
-				    &tt->ipapi_instance)) == NO_ERROR)
-	  msg (M_INFO, "Succeeded in adding a temporary IP/netmask of %s/%s to interface %s using the Win32 IP Helper API",
-	       print_in_addr_t (tt->local, 0, &gc),
-	       print_in_addr_t (tt->adapter_netmask, 0, &gc),
-	       device_guid
-	       );
-	else
-	  msg (M_FATAL, "ERROR: AddIPAddress %s/%s failed on interface %s, index=%d, status=%u (windows error: '%s') -- %s",
-	       print_in_addr_t (tt->local, 0, &gc),
-	       print_in_addr_t (tt->adapter_netmask, 0, &gc),
-	       device_guid,
-	       (int)index,
-	       (unsigned int)status,
-	       strerror_win32 (status, &gc),
-	       error_suffix);
-	tt->ipapi_context_defined = true;
-      }
-  }
-  /*netcmd_semaphore_release ();*/
-  gc_free (&gc);
-}
-
-const char *
-tap_win32_getinfo (const struct tuntap *tt, struct gc_arena *gc)
-{
-  if (tt && tt->hand != NULL)
-    {
-      struct buffer out = alloc_buf_gc (256, gc);
-      DWORD len;
-      if (DeviceIoControl (tt->hand, TAP_IOCTL_GET_INFO,
-			   BSTR (&out), BCAP (&out),
-			   BSTR (&out), BCAP (&out),
-			   &len, NULL))
-	{
-	  return BSTR (&out);
-	}
-    }
-  return NULL;
-}
-
-void
-tun_show_debug (struct tuntap *tt)
-{
-  if (tt && tt->hand != NULL)
-    {
-      struct buffer out = alloc_buf (1024);
-      DWORD len;
-      while (DeviceIoControl (tt->hand, TAP_IOCTL_GET_LOG_LINE,
-			      BSTR (&out), BCAP (&out),
-			      BSTR (&out), BCAP (&out),
-			      &len, NULL))
-	{
-	  msg (D_TAP_WIN32_DEBUG, "TAP-Win32: %s", BSTR (&out));
-	}
-      free_buf (&out);
-    }
-}
-
-void
-close_tun (struct tuntap *tt)
-{
-  struct gc_arena gc = gc_new ();
-
-  if (tt)
-    {
-#if 1
-      if (tt->ipapi_context_defined)
-	{
-	  DWORD status;
-	  if ((status = DeleteIPAddress (tt->ipapi_context)) != NO_ERROR)
-	    {
-	      msg (M_WARN, "Warning: DeleteIPAddress[%u] failed on TAP-Win32 adapter, status=%u : %s",
-		   (unsigned int)tt->ipapi_context,
-		   (unsigned int)status,
-		   strerror_win32 (status, &gc));
-	    }
-	}
-#endif
-
-      if (tt->options.dhcp_release)
-	dhcp_release (tt);
-
-      if (tt->hand != NULL)
-	{
-	  dmsg (D_WIN32_IO_LOW, "Attempting CancelIO on TAP-Win32 adapter");
-	  if (!CancelIo (tt->hand))
-	    msg (M_WARN | M_ERRNO, "Warning: CancelIO failed on TAP-Win32 adapter");
-	}
-
-      dmsg (D_WIN32_IO_LOW, "Attempting close of overlapped read event on TAP-Win32 adapter");
-      overlapped_io_close (&tt->reads);
-
-      dmsg (D_WIN32_IO_LOW, "Attempting close of overlapped write event on TAP-Win32 adapter");
-      overlapped_io_close (&tt->writes);
-
-      if (tt->hand != NULL)
-	{
-	  dmsg (D_WIN32_IO_LOW, "Attempting CloseHandle on TAP-Win32 adapter");
-	  if (!CloseHandle (tt->hand))
-	    msg (M_WARN | M_ERRNO, "Warning: CloseHandle failed on TAP-Win32 adapter");
-	}
-
-      if (tt->actual_name)
-	free (tt->actual_name);
-
-      clear_tuntap (tt);
-      free (tt);
-    }
-  gc_free (&gc);
-}
-
-/*
- * Convert --ip-win32 constants between index and ascii form.
- */
-
-struct ipset_names {
-  const char *short_form;
-};
-
-/* Indexed by IPW32_SET_x */
-static const struct ipset_names ipset_names[] = {
-  {"manual"},
-  {"netsh"},
-  {"ipapi"},
-  {"dynamic"}
-};
-
-int
-ascii2ipset (const char* name)
-{
-  int i;
-  ASSERT (IPW32_SET_N == SIZE (ipset_names));
-  for (i = 0; i < IPW32_SET_N; ++i)
-    if (!strcmp (name, ipset_names[i].short_form))
-      return i;
-  return -1;
-}
-
-const char *
-ipset2ascii (int index)
-{
-  ASSERT (IPW32_SET_N == SIZE (ipset_names));
-  if (index < 0 || index >= IPW32_SET_N)
-    return "[unknown --ip-win32 type]";
-  else
-    return ipset_names[index].short_form;
-}
-
-const char *
-ipset2ascii_all (struct gc_arena *gc)
-{
-  struct buffer out = alloc_buf_gc (256, gc);
-  int i;
-
-  ASSERT (IPW32_SET_N == SIZE (ipset_names));
-  for (i = 0; i < IPW32_SET_N; ++i)
-    {
-      if (i)
-	buf_printf(&out, " ");
-      buf_printf(&out, "[%s]", ipset2ascii(i));
-    }
-  return BSTR (&out);
-}
-
-#else /* generic */
-
-void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
-{
-  open_tun_generic (dev, dev_type, dev_node, ipv6, false, true, tt);
-}
-
-void
-close_tun (struct tuntap* tt)
-{
-  if (tt)
-    {
-      close_tun_generic (tt);
-      free (tt);
-    }
-}
-
-int
-write_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  return write (tt->fd, buf, len);
-}
-
-int
-read_tun (struct tuntap* tt, uint8_t *buf, int len)
-{
-  return read (tt->fd, buf, len);
-}
-
-#endif