path: root/main/openvpn/openvpn-2.2.2-ipv6.patch

diff --git a/forward.c b/forward.c
index 87d05cc..1f3d435 100644
--- a/forward.c
+++ b/forward.c
@@ -262,7 +262,8 @@ send_control_channel_string (struct context *c, const char *str, int msglevel)
 static void
 check_add_routes_action (struct context *c, const bool errors)
 {
-  do_route (&c->options, c->c1.route_list, c->c1.tuntap, c->plugins, c->c2.es);
+  do_route (&c->options, c->c1.route_list, c->c1.route_ipv6_list,
+	    c->c1.tuntap, c->plugins, c->c2.es);
   update_time ();
   event_timeout_clear (&c->c2.route_wakeup);
   event_timeout_clear (&c->c2.route_wakeup_expire);
diff --git a/helper.c b/helper.c
index a9d7fd9..266b246 100644
--- a/helper.c
+++ b/helper.c
@@ -142,6 +142,55 @@ helper_client_server (struct options *o)
 
 #if P2MP
 #if P2MP_SERVER
+
+  /* 
+   *
+   * HELPER DIRECTIVE for IPv6
+   *
+   * server-ipv6 2001:db8::/64
+   *
+   * EXPANDS TO:
+   *
+   * tun-ipv6
+   * push "tun-ipv6"
+   * ifconfig-ipv6 2001:db8::1 2001:db8::2
+   * if !nopool: 
+   *   ifconfig-ipv6-pool 2001:db8::1:0/64
+   * 
+   */
+   if ( o->server_ipv6_defined )
+     {
+	if ( ! o->server_defined )
+	  {
+	    msg (M_USAGE, "--server-ipv6 must be used together with --server");
+	  }
+	if ( o->server_flags & SF_NOPOOL )
+	  {
+	    msg( M_USAGE, "--server-ipv6 is incompatible with 'nopool' option" );
+	  }
+	if ( o->ifconfig_ipv6_pool_defined )
+	  {
+	    msg( M_USAGE, "--server-ipv6 already defines an ifconfig-ipv6-pool, so you can't also specify --ifconfig-pool explicitly");
+	  }
+
+        /* local ifconfig is "base address + 1" and "+2" */
+	o->ifconfig_ipv6_local = 
+		print_in6_addr( add_in6_addr( o->server_network_ipv6, 1), 0, &o->gc );
+	o->ifconfig_ipv6_remote = 
+		print_in6_addr( add_in6_addr( o->server_network_ipv6, 2), 0, &o->gc );
+
+	/* pool starts at "base address + 0x10000" */
+	ASSERT( o->server_netbits_ipv6 < 96 );		/* want 32 bits */
+	o->ifconfig_ipv6_pool_defined = true;
+	o->ifconfig_ipv6_pool_base = 
+		add_in6_addr( o->server_network_ipv6, 0x10000 );
+	o->ifconfig_ipv6_pool_netbits = o->server_netbits_ipv6;
+
+	o->tun_ipv6 = true;
+
+	push_option( o, "tun-ipv6", M_USAGE );
+     }
+
   /*
    *
    * HELPER DIRECTIVE:
diff --git a/init.c b/init.c
index d47a4ef..7fc8eb7 100644
--- a/init.c
+++ b/init.c
@@ -843,7 +843,7 @@ do_persist_tuntap (const struct options *options)
 	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,
+	      options->persist_mode,
 	      options->username, options->groupname, &options->tuntap_options);
       if (options->persist_mode && options->lladdr)
         set_lladdr(options->dev, options->lladdr, NULL);
@@ -1066,6 +1066,8 @@ do_alloc_route_list (struct context *c)
 {
   if (c->options.routes && !c->c1.route_list)
     c->c1.route_list = new_route_list (c->options.max_routes, &c->gc);
+  if (c->options.routes_ipv6 && !c->c1.route_ipv6_list)
+    c->c1.route_ipv6_list = new_route_ipv6_list (c->options.max_routes, &c->gc);
 }
 
 
@@ -1108,6 +1110,45 @@ do_init_route_list (const struct options *options,
     }
 }
 
+static void
+do_init_route_ipv6_list (const struct options *options,
+		    struct route_ipv6_list *route_ipv6_list,
+		    bool fatal,
+		    struct env_set *es)
+{
+  const char *gw = NULL;
+  int dev = dev_type_enum (options->dev, options->dev_type);
+  int metric = 0;
+
+  if (dev != DEV_TYPE_TUN )
+    msg( M_WARN, "IPv6 routes on TAP devices are going to fail on some platforms (need gateway spec)" );	/* TODO-GERT */
+
+  gw = options->ifconfig_ipv6_remote;		/* default GW = remote end */
+#if 0					/* not yet done for IPv6 - TODO!*/
+  if ( options->route_ipv6_default_gateway )		/* override? */
+    gw = options->route_ipv6_default_gateway;
+#endif
+
+  if (options->route_default_metric)
+    metric = options->route_default_metric;
+
+  if (!init_route_ipv6_list (route_ipv6_list,
+			options->routes_ipv6,
+			gw,
+			metric,
+			es))
+    {
+      if (fatal)
+	openvpn_exit (OPENVPN_EXIT_STATUS_ERROR);	/* exit point */
+    }
+  else
+    {
+      /* copy routes to environment */
+      setenv_routes_ipv6 (es, route_ipv6_list);
+    }
+}
+
+
 /*
  * Called after all initialization has been completed.
  */
@@ -1172,12 +1213,13 @@ initialization_sequence_completed (struct context *c, const unsigned int flags)
 void
 do_route (const struct options *options,
 	  struct route_list *route_list,
+	  struct route_ipv6_list *route_ipv6_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 (!options->route_noexec && ( route_list || route_ipv6_list ) )
+    add_routes (route_list, route_ipv6_list, tt, ROUTE_OPTION_FLAGS (options), es);
 
   if (plugin_defined (plugins, OPENVPN_PLUGIN_ROUTE_UP))
     {
@@ -1234,11 +1276,16 @@ do_init_tun (struct context *c)
 			   c->options.topology,
 			   c->options.ifconfig_local,
 			   c->options.ifconfig_remote_netmask,
+			   c->options.ifconfig_ipv6_local,
+			   c->options.ifconfig_ipv6_remote,
 			   addr_host (&c->c1.link_socket_addr.local),
 			   addr_host (&c->c1.link_socket_addr.remote),
 			   !c->options.ifconfig_nowarn,
 			   c->c2.es);
 
+  /* flag tunnel for IPv6 config if --tun-ipv6 is set */
+  c->c1.tuntap->ipv6 = c->options.tun_ipv6;
+
   init_tun_post (c->c1.tuntap,
 		 &c->c2.frame,
 		 &c->options.tuntap_options);
@@ -1270,6 +1317,8 @@ do_open_tun (struct context *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);
+      if (c->options.routes_ipv6 && c->c1.route_ipv6_list )
+	do_init_route_ipv6_list (&c->options, c->c1.route_ipv6_list, false, c->c2.es);
 
       /* do ifconfig */
       if (!c->options.ifconfig_noexec
@@ -1286,7 +1335,7 @@ do_open_tun (struct context *c)
 
       /* open the tun device */
       open_tun (c->options.dev, c->options.dev_type, c->options.dev_node,
-		c->options.tun_ipv6, c->c1.tuntap);
+		c->c1.tuntap);
 
       /* set the hardware address */
       if (c->options.lladdr)
@@ -1315,7 +1364,8 @@ do_open_tun (struct context *c)
 
       /* 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);
+	do_route (&c->options, c->c1.route_list, c->c1.route_ipv6_list,
+		  c->c1.tuntap, c->plugins, c->c2.es);
 
       /*
        * Did tun/tap driver give us an MTU?
@@ -1389,8 +1439,9 @@ do_close_tun (struct context *c, bool force)
 #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);
+	  if (c->c1.route_list || c->c1.route_ipv6_list )
+	    delete_routes (c->c1.route_list, c->c1.route_ipv6_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)
diff --git a/init.h b/init.h
index cf5ca8a..5a1d1dc 100644
--- a/init.h
+++ b/init.h
@@ -63,6 +63,7 @@ void init_instance (struct context *c, const struct env_set *env, const unsigned
 
 void do_route (const struct options *options,
 	       struct route_list *route_list,
+	       struct route_ipv6_list *route_ipv6_list,
 	       const struct tuntap *tt,
 	       const struct plugin_list *plugins,
 	       struct env_set *es);
diff --git a/misc.c b/misc.c
index 4067d85..9d351f4 100644
--- a/misc.c
+++ b/misc.c
@@ -1001,7 +1001,9 @@ setenv_str_ex (struct env_set *es,
 	{
 	  const char *str = construct_name_value (name_tmp, val_tmp, &gc);
 	  env_set_add (es, str);
-	  /*msg (M_INFO, "SETENV_ES '%s'", str);*/
+#if DEBUG_VERBOSE_SETENV
+	  msg (M_INFO, "SETENV_ES '%s'", str);
+#endif
 	}
       else
 	env_set_del (es, name_tmp);
diff --git a/mroute.c b/mroute.c
index 1b3488f..6cfec27 100644
--- a/mroute.c
+++ b/mroute.c
@@ -88,12 +88,33 @@ mroute_get_in_addr_t (struct mroute_addr *ma, const in_addr_t src, unsigned int
     }
 }
 
+static inline void
+mroute_get_in6_addr (struct mroute_addr *ma, const struct in6_addr src, unsigned int mask)
+{
+  if (ma)
+    {
+      ma->type = MR_ADDR_IPV6 | mask;
+      ma->netbits = 0;
+      ma->len = 16;
+      *(struct in6_addr *)ma->addr = src;
+    }
+}
+
 static inline bool
 mroute_is_mcast (const in_addr_t addr)
 {
   return ((addr & htonl(IP_MCAST_SUBNET_MASK)) == htonl(IP_MCAST_NETWORK));
 }
 
+/* RFC 4291, 2.7, "binary 11111111 at the start of an address identifies 
+ *                 the address as being a multicast address"
+ */
+static inline bool
+mroute_is_mcast_ipv6 (const struct in6_addr addr)
+{
+  return (addr.s6_addr[0] == 0xff);
+}
+
 #ifdef ENABLE_PF
 
 static unsigned int
@@ -157,13 +178,29 @@ mroute_extract_addr_ipv4 (struct mroute_addr *src,
 	    }
 	  break;
 	case 6:
-	  {
-            if( !ipv6warned ) {
-              msg (M_WARN, "IPv6 in tun mode is not supported in OpenVPN 2.2");
-              ipv6warned = true;
-            }
-	    break;
-	  }
+         if (BLEN (buf) >= (int) sizeof (struct openvpn_ipv6hdr))
+           {
+             const struct openvpn_ipv6hdr *ipv6 = (const struct openvpn_ipv6hdr *) BPTR (buf);
+#if 0                          /* very basic debug */
+             struct gc_arena gc = gc_new ();
+             msg( M_INFO, "IPv6 packet! src=%s, dst=%s",
+                       print_in6_addr( ipv6->saddr, 0, &gc ),
+                       print_in6_addr( ipv6->daddr, 0, &gc ));
+             gc_free (&gc);
+#endif
+
+             mroute_get_in6_addr (src, ipv6->saddr, 0);
+             mroute_get_in6_addr (dest, ipv6->daddr, 0);
+
+             if (mroute_is_mcast_ipv6 (ipv6->daddr))
+               ret |= MROUTE_EXTRACT_MCAST;
+
+             ret |= MROUTE_EXTRACT_SUCCEEDED;
+           }
+         break;
+       default:
+           msg (M_WARN, "IP packet with unknown IP version=%d seen",
+                        OPENVPN_IPH_GET_VER (*BPTR(buf)));
 	}
     }
   return ret;
@@ -257,14 +294,36 @@ bool mroute_extract_openvpn_sockaddr (struct mroute_addr *addr,
  * Zero off the host bits in an address, leaving
  * only the network bits, using the netbits member of
  * struct mroute_addr as the controlling parameter.
+ *
+ * TODO: this is called for route-lookup for every yet-unhashed
+ * destination address, so for lots of active net-iroutes, this
+ * might benefit from some "zeroize 32 bit at a time" improvements
  */
 void
 mroute_addr_mask_host_bits (struct mroute_addr *ma)
 {
   in_addr_t addr = ntohl(*(in_addr_t*)ma->addr);
-  ASSERT ((ma->type & MR_ADDR_MASK) == MR_ADDR_IPV4);
-  addr &= netbits_to_netmask (ma->netbits);
-  *(in_addr_t*)ma->addr = htonl (addr);
+  if ((ma->type & MR_ADDR_MASK) == MR_ADDR_IPV4)
+    {
+      addr &= netbits_to_netmask (ma->netbits);
+      *(in_addr_t*)ma->addr = htonl (addr);
+    }
+  else if ((ma->type & MR_ADDR_MASK) == MR_ADDR_IPV6)
+    {
+      int byte = ma->len-1;		/* rightmost byte in address */
+      int bits_to_clear = 128 - ma->netbits;
+
+      while( byte >= 0 && bits_to_clear > 0 )
+        {
+	  if ( bits_to_clear >= 8 )
+	    { ma->addr[byte--] = 0; bits_to_clear -= 8; }
+	  else
+	    { ma->addr[byte--] &= (~0 << bits_to_clear); bits_to_clear = 0; }
+        }
+      ASSERT( bits_to_clear == 0 );
+    }
+  else
+      ASSERT(0);
 }
 
 /*
@@ -342,17 +401,24 @@ mroute_addr_print_ex (const struct mroute_addr *ma,
 	  }
 	  break;
 	case MR_ADDR_IPV6:
-	  buf_printf (&out, "IPV6"); 
-	  break;
-	default:
-	  buf_printf (&out, "UNKNOWN"); 
-	  break;
-	}
-      return BSTR (&out);
-    }
-  else
-    return "[NULL]";
-}
+	  {
+	    buf_printf (&out, "%s",
+		  print_in6_addr( *(struct in6_addr*)&maddr.addr, 0, gc)); 
+	    if (maddr.type & MR_WITH_NETBITS)
+	      {
+		buf_printf (&out, "/%d", maddr.netbits);
+	      }
+	    }
+	    break;
+	  default:
+	    buf_printf (&out, "UNKNOWN"); 
+	    break;
+	  }
+	return BSTR (&out);
+      }
+    else
+      return "[NULL]";
+  }
 
 /*
  * mroute_helper's main job is keeping track of
@@ -423,6 +489,40 @@ mroute_helper_del_iroute (struct mroute_helper *mh, const struct iroute *ir)
     }
 }
 
+/* this is a bit inelegant, we really should have a helper to that 
+ * is only passed the netbits value, and not the whole struct iroute *
+ * - thus one helper could do IPv4 and IPv6.  For the sake of "not change
+ * code unrelated to IPv4" this is left for later cleanup, for now.
+ */
+void
+mroute_helper_add_iroute6 (struct mroute_helper *mh, 
+                           const struct iroute_ipv6 *ir6)
+{
+  if (ir6->netbits >= 0)
+    {
+      ASSERT (ir6->netbits < MR_HELPER_NET_LEN);
+      ++mh->cache_generation;
+      ++mh->net_len_refcount[ir6->netbits];
+      if (mh->net_len_refcount[ir6->netbits] == 1)
+	mroute_helper_regenerate (mh);
+    }
+}
+
+void
+mroute_helper_del_iroute6 (struct mroute_helper *mh, 
+			   const struct iroute_ipv6 *ir6)
+{
+  if (ir6->netbits >= 0)
+    {
+      ASSERT (ir6->netbits < MR_HELPER_NET_LEN);
+      ++mh->cache_generation;
+      --mh->net_len_refcount[ir6->netbits];
+      ASSERT (mh->net_len_refcount[ir6->netbits] >= 0);
+      if (!mh->net_len_refcount[ir6->netbits])
+	mroute_helper_regenerate (mh);
+    }
+}
+
 void
 mroute_helper_free (struct mroute_helper *mh)
 {
diff --git a/mroute.h b/mroute.h
index 7265001..b72b5ff 100644
--- a/mroute.h
+++ b/mroute.h
@@ -85,7 +85,7 @@ struct mroute_addr {
 /*
  * Number of bits in an address.  Should be raised for IPv6.
  */
-#define MR_HELPER_NET_LEN 32
+#define MR_HELPER_NET_LEN 129
 
 /*
  * Used to help maintain CIDR routing table.
@@ -127,6 +127,8 @@ struct mroute_helper *mroute_helper_init (int ageable_ttl_secs);
 void mroute_helper_free (struct mroute_helper *mh);
 void mroute_helper_add_iroute (struct mroute_helper *mh, const struct iroute *ir);
 void mroute_helper_del_iroute (struct mroute_helper *mh, const struct iroute *ir);
+void mroute_helper_add_iroute6 (struct mroute_helper *mh, const struct iroute_ipv6 *ir6);
+void mroute_helper_del_iroute6 (struct mroute_helper *mh, const struct iroute_ipv6 *ir6);
 
 /*
  * Given a raw packet in buf, return the src and dest
diff --git a/multi.c b/multi.c
index 22c0a3f..f703b8d 100644
--- a/multi.c
+++ b/multi.c
@@ -316,25 +316,18 @@ multi_init (struct multi_context *m, struct context *t, bool tcp_mode, int threa
    */
   if (t->options.ifconfig_pool_defined)
     {
-      if (dev == DEV_TYPE_TAP)
-	{
-	  m->ifconfig_pool = ifconfig_pool_init (IFCONFIG_POOL_INDIV,
-						 t->options.ifconfig_pool_start,
-						 t->options.ifconfig_pool_end,
-						 t->options.duplicate_cn);
-	}
-      else if (dev == DEV_TYPE_TUN)
-	{
-	  m->ifconfig_pool = ifconfig_pool_init (
-	    (t->options.topology == TOP_NET30) ? IFCONFIG_POOL_30NET : IFCONFIG_POOL_INDIV,
-	    t->options.ifconfig_pool_start,
-	    t->options.ifconfig_pool_end,
-	    t->options.duplicate_cn);
-	}
-      else
-	{
-	  ASSERT (0);
-	}
+      int pool_type = IFCONFIG_POOL_INDIV;
+
+      if ( dev == DEV_TYPE_TUN && t->options.topology == TOP_NET30 )
+	pool_type = IFCONFIG_POOL_30NET;
+
+      m->ifconfig_pool = ifconfig_pool_init (pool_type,
+				 t->options.ifconfig_pool_start,
+				 t->options.ifconfig_pool_end,
+				 t->options.duplicate_cn,
+				 t->options.ifconfig_ipv6_pool_defined,
+				 t->options.ifconfig_ipv6_pool_base,
+				 t->options.ifconfig_ipv6_pool_netbits );
 
       /* reload pool data from file */
       if (t->c1.ifconfig_pool_persist)
@@ -429,10 +422,14 @@ multi_del_iroutes (struct multi_context *m,
 		   struct multi_instance *mi)
 {
   const struct iroute *ir;
+  const struct iroute_ipv6 *ir6;
   if (TUNNEL_TYPE (mi->context.c1.tuntap) == DEV_TYPE_TUN)
     {
       for (ir = mi->context.options.iroutes; ir != NULL; ir = ir->next)
 	mroute_helper_del_iroute (m->route_helper, ir);
+
+      for ( ir6 = mi->context.options.iroutes_ipv6; ir6 != NULL; ir6 = ir6->next )
+	mroute_helper_del_iroute6 (m->route_helper, ir6);
     }
 }
 
@@ -1078,6 +1075,37 @@ multi_learn_in_addr_t (struct multi_context *m,
   }
 }
 
+static struct multi_instance *
+multi_learn_in6_addr  (struct multi_context *m,
+		       struct multi_instance *mi,
+		       struct in6_addr a6,
+		       int netbits, /* -1 if host route, otherwise # of network bits in address */
+		       bool primary)
+{
+  struct mroute_addr addr;
+
+  addr.len = 16;
+  addr.type = MR_ADDR_IPV6;
+  addr.netbits = 0;
+  memcpy( &addr.addr, &a6, sizeof(a6) );
+
+  if (netbits >= 0)
+    {
+      addr.type |= MR_WITH_NETBITS;
+      addr.netbits = (uint8_t) netbits;
+      mroute_addr_mask_host_bits( &addr );
+    }
+
+  {
+    struct multi_instance *owner = multi_learn_addr (m, mi, &addr, 0);
+#ifdef MANAGEMENT_DEF_AUTH
+    if (management && owner)
+      management_learn_addr (management, &mi->context.c2.mda_context, &addr, primary);
+#endif
+    return owner;
+  }
+}
+
 /*
  * A new client has connected, add routes (server -> client)
  * to internal routing table.
@@ -1088,6 +1116,7 @@ multi_add_iroutes (struct multi_context *m,
 {
   struct gc_arena gc = gc_new ();
   const struct iroute *ir;
+  const struct iroute_ipv6 *ir6;
   if (TUNNEL_TYPE (mi->context.c1.tuntap) == DEV_TYPE_TUN)
     {
       mi->did_iroutes = true;
@@ -1107,6 +1136,22 @@ multi_add_iroutes (struct multi_context *m,
       
 	  multi_learn_in_addr_t (m, mi, ir->network, ir->netbits, false);
 	}
+      for ( ir6 = mi->context.options.iroutes_ipv6; ir6 != NULL; ir6 = ir6->next )
+	{
+	  if (ir6->netbits >= 0)
+	    msg (D_MULTI_LOW, "MULTI: internal route %s/%d -> %s",
+		 print_in6_addr (ir6->network, 0, &gc),
+		 ir6->netbits,
+		 multi_instance_string (mi, false, &gc));
+	  else
+	    msg (D_MULTI_LOW, "MULTI: internal route %s -> %s",
+		 print_in6_addr (ir6->network, 0, &gc),
+		 multi_instance_string (mi, false, &gc));
+
+	  mroute_helper_add_iroute6 (m->route_helper, ir6);
+      
+	  multi_learn_in6_addr (m, mi, ir6->network, ir6->netbits, false);
+	}
     }
   gc_free (&gc);
 }
@@ -1192,21 +1237,37 @@ multi_select_virtual_addr (struct multi_context *m, struct multi_instance *mi)
       mi->context.c2.push_ifconfig_defined = true;
       mi->context.c2.push_ifconfig_local = mi->context.options.push_ifconfig_local;
       mi->context.c2.push_ifconfig_remote_netmask = mi->context.options.push_ifconfig_remote_netmask;
+
+      /* the current implementation does not allow "static IPv4, pool IPv6",
+       * (see below) so issue a warning if that happens - don't break the
+       * session, though, as we don't even know if this client WANTS IPv6
+       */
+      if ( mi->context.c1.tuntap->ipv6 &&
+	   mi->context.options.ifconfig_ipv6_pool_defined &&
+	   ! mi->context.options.push_ifconfig_ipv6_defined )
+	{
+	  msg( M_INFO, "MULTI_sva: WARNING: if --ifconfig-push is used for IPv4, automatic IPv6 assignment from --ifconfig-ipv6-pool does not work.  Use --ifconfig-ipv6-push for IPv6 then." );
+	}
     }
   else if (m->ifconfig_pool && mi->vaddr_handle < 0) /* otherwise, choose a pool address */
     {
       in_addr_t local=0, remote=0;
+      struct in6_addr remote_ipv6;
       const char *cn = NULL;
 
       if (!mi->context.options.duplicate_cn)
 	cn = tls_common_name (mi->context.c2.tls_multi, true);
 
-      mi->vaddr_handle = ifconfig_pool_acquire (m->ifconfig_pool, &local, &remote, cn);
+      mi->vaddr_handle = ifconfig_pool_acquire (m->ifconfig_pool, &local, &remote, &remote_ipv6, cn);
       if (mi->vaddr_handle >= 0)
 	{
 	  const int tunnel_type = TUNNEL_TYPE (mi->context.c1.tuntap);
 	  const int tunnel_topology = TUNNEL_TOPOLOGY (mi->context.c1.tuntap);
 
+	  msg( M_INFO, "MULTI_sva: pool returned IPv4=%s, IPv6=%s", 
+		    print_in_addr_t( remote, 0, &gc ),
+		    print_in6_addr( remote_ipv6, 0, &gc ) );
+
 	  /* set push_ifconfig_remote_netmask from pool ifconfig address(es) */
 	  mi->context.c2.push_ifconfig_local = remote;
 	  if (tunnel_type == DEV_TYPE_TAP || (tunnel_type == DEV_TYPE_TUN && tunnel_topology == TOP_SUBNET))
@@ -1228,12 +1289,46 @@ multi_select_virtual_addr (struct multi_context *m, struct multi_instance *mi)
 	  else
 	    msg (D_MULTI_ERRORS, "MULTI: no --ifconfig-pool netmask parameter is available to push to %s",
 		 multi_instance_string (mi, false, &gc));
+
+	  if ( mi->context.options.ifconfig_ipv6_pool_defined )
+	    {
+	      mi->context.c2.push_ifconfig_ipv6_local = remote_ipv6;
+	      mi->context.c2.push_ifconfig_ipv6_remote = 
+		    mi->context.c1.tuntap->local_ipv6;
+	      mi->context.c2.push_ifconfig_ipv6_netbits = 
+		    mi->context.options.ifconfig_ipv6_pool_netbits;
+	      mi->context.c2.push_ifconfig_ipv6_defined = true;
+	    }
 	}
       else
 	{
 	  msg (D_MULTI_ERRORS, "MULTI: no free --ifconfig-pool addresses are available");
 	}
     }
+
+  /* IPv6 push_ifconfig is a bit problematic - since IPv6 shares the 
+   * pool handling with IPv4, the combination "static IPv4, dynamic IPv6"
+   * will fail (because no pool will be allocated in this case).
+   * OTOH, this doesn't make too much sense in reality - and the other
+   * way round ("dynamic IPv4, static IPv6") or "both static" makes sense
+   * -> and so it's implemented right now
+   */
+  if ( mi->context.c1.tuntap->ipv6 &&
+       mi->context.options.push_ifconfig_ipv6_defined )
+    {
+      mi->context.c2.push_ifconfig_ipv6_local = 
+	    mi->context.options.push_ifconfig_ipv6_local;
+      mi->context.c2.push_ifconfig_ipv6_remote = 
+	    mi->context.options.push_ifconfig_ipv6_remote;
+      mi->context.c2.push_ifconfig_ipv6_netbits = 
+	    mi->context.options.push_ifconfig_ipv6_netbits;
+      mi->context.c2.push_ifconfig_ipv6_defined = true;
+
+      msg( M_INFO, "MULTI_sva: push_ifconfig_ipv6 %s/%d", 
+	    print_in6_addr( mi->context.c2.push_ifconfig_ipv6_local, 0, &gc ),
+	    mi->context.c2.push_ifconfig_ipv6_netbits );
+    }
+
   gc_free (&gc);
 }
 
@@ -1272,6 +1367,11 @@ multi_set_virtual_addr_env (struct multi_context *m, struct multi_instance *mi)
 			    SA_SET_IF_NONZERO);
 	}
     }
+
+    /* TODO: I'm not exactly sure what these environment variables are
+     *       used for, but if we have them for IPv4, we should also have
+     *       them for IPv6, no?
+     */
 }
 
 /*
@@ -1661,6 +1761,15 @@ multi_connection_established (struct multi_context *m, struct multi_instance *mi
 		       print_in_addr_t (mi->context.c2.push_ifconfig_local, 0, &gc));
 		}
 
+	      if (mi->context.c2.push_ifconfig_ipv6_defined)
+		{
+		  multi_learn_in6_addr (m, mi, mi->context.c2.push_ifconfig_ipv6_local, -1, true);
+		  /* TODO: find out where addresses are "unlearned"!! */
+		  msg (D_MULTI_LOW, "MULTI: primary virtual IPv6 for %s: %s",
+		       multi_instance_string (mi, false, &gc),
+		       print_in6_addr (mi->context.c2.push_ifconfig_ipv6_local, 0, &gc));
+		}
+
 	      /* add routes locally, pointing to new client, if
 		 --iroute options have been specified */
 	      multi_add_iroutes (m, mi);
diff --git a/openvpn.8 b/openvpn.8
index 67a9779..5322618 100644
--- a/openvpn.8
+++ b/openvpn.8
@@ -794,6 +794,8 @@ or
 .B \-\-dev tunX.
 A warning will be displayed
 if no specific IPv6 TUN support for your OS has been compiled into OpenVPN.
+
+See below for further IPv6-related configuration options.
 .\"*********************************************************
 .TP
 .B \-\-dev-node node
@@ -4949,6 +4951,57 @@ if certificates are stored as private objects.
 .B \-\-verb
 option can be used BEFORE this option to produce debugging information.
 .\"*********************************************************
+.SS IPv6 Related Options
+.\"*********************************************************
+The following options exist to support IPv6 tunneling in peer-to-peer
+and client-server mode.  As of now, this is just very basic
+documentation of the IPv6-related options. More documentation can be
+found on http://www.greenie.net/ipv6/openvpn.html.
+.TP
+.B --ifconfig-ipv6 ipv6addr/bits ipv6remote
+configure IPv6 address
+.B ipv6addr/bits
+on the ``tun'' device.  The second parameter is used as route target for
+.B --route-ipv6
+if no gateway is specified.
+.TP
+.B --route-ipv6 ipv6addr/bits [gateway] [metric]
+setup IPv6 routing in the system to send the specified IPv6 network
+into OpenVPN's ``tun'' device
+.TP
+.B --server-ipv6 ipv6addr/bits
+convenience-function to enable a number of IPv6 related options at
+once, namely
+.B --ifconfig-ipv6, --ifconfig-ipv6-pool, --tun-ipv6
+and
+.B --push tun-ipv6
+Is only accepted if ``--mode server'' or ``--server'' is set.
+.TP
+.B --ifconfig-ipv6-pool ipv6addr/bits
+Specify an IPv6 address pool for dynamic assignment to clients.  The
+pool starts at
+.B ipv6addr
+and increments by +1 for every new client (linear mode).  The
+.B /bits
+setting controls the size of the pool.
+.TP
+.B --ifconfig-ipv6-push ipv6addr/bits ipv6remote
+for ccd/ per-client static IPv6 interface configuration, see
+.B --client-config-dir
+and
+.B --ifconfig-push
+for more details.
+.TP
+.B --iroute-ipv6 ipv6addr/bits
+for ccd/ per-client static IPv6 route configuration, see
+.B --iroute
+for more details how to setup and use this, and how
+.B --iroute
+and
+.B --route
+interact.
+
+.\"*********************************************************
 .SH SCRIPTING AND ENVIRONMENTAL VARIABLES
 OpenVPN exports a series
 of environmental variables for use by user-defined scripts.
diff --git a/openvpn.h b/openvpn.h
index 641bf93..e5e6e58 100644
--- a/openvpn.h
+++ b/openvpn.h
@@ -165,6 +165,9 @@ struct context_1
   /* list of --route directives */
   struct route_list *route_list;
 
+  /* list of --route-ipv6 directives */
+  struct route_ipv6_list *route_ipv6_list;
+
   /* --status file */
   struct status_output *status_output;
   bool status_output_owned;
@@ -417,6 +420,11 @@ struct context_2
   in_addr_t push_ifconfig_local;
   in_addr_t push_ifconfig_remote_netmask;
 
+  bool            push_ifconfig_ipv6_defined;
+  struct in6_addr push_ifconfig_ipv6_local;
+  int             push_ifconfig_ipv6_netbits;
+  struct in6_addr push_ifconfig_ipv6_remote;
+
   /* client authentication state, CAS_SUCCEEDED must be 0 */
 # define CAS_SUCCEEDED 0
 # define CAS_PENDING   1
diff --git a/options.c b/options.c
index 7a5e35d..8fdd8a5 100644
--- a/options.c
+++ b/options.c
@@ -79,6 +79,7 @@ const char title_string[] =
 #ifdef ENABLE_EUREPHIA
   " [eurephia]"
 #endif
+  " [IPv6 payload 20110522-1 (2.2.0)]"
   " built on " __DATE__
 ;
 
@@ -172,6 +173,8 @@ static const char usage_message[] =
   "                  addresses outside of the subnets used by either peer.\n"
   "                  TAP: configure device to use IP address l as a local\n"
   "                  endpoint and rn as a subnet mask.\n"
+  "--ifconfig-ipv6 l r : configure device to use IPv6 address l as local\n"
+  "                      endpoint (as a /64) and r as remote endpoint\n"
   "--ifconfig-noexec : Don't actually execute ifconfig/netsh command, instead\n"
   "                    pass --ifconfig parms by environment to scripts.\n"
   "--ifconfig-nowarn : Don't warn if the --ifconfig option on this side of the\n"
@@ -182,6 +185,10 @@ static const char usage_message[] =
   "                  netmask default: 255.255.255.255\n"
   "                  gateway default: taken from --route-gateway or --ifconfig\n"
   "                  Specify default by leaving blank or setting to \"nil\".\n"
+  "--route-ipv6 network/bits [gateway] [metric] :\n"
+  "                  Add IPv6 route to routing table after connection\n"
+  "                  is established.  Multiple routes can be specified.\n"
+  "                  gateway default: taken from --route-ipv6-gateway or --ifconfig\n"
   "--max-routes n :  Specify the maximum number of routes that may be defined\n"
   "                  or pulled from a server.\n"
   "--route-gateway gw|'dhcp' : Specify a default gateway for use with --route.\n"
@@ -370,6 +377,7 @@ static const char usage_message[] =
   "\n"
   "Multi-Client Server options (when --mode server is used):\n"
   "--server network netmask : Helper option to easily configure server mode.\n"
+  "--server-ipv6 network/bits : Configure IPv6 server mode.\n"
   "--server-bridge [IP netmask pool-start-IP pool-end-IP] : Helper option to\n"
   "                    easily configure ethernet bridging server mode.\n"
   "--push \"option\" : Push a config file option back to the peer for remote\n"
@@ -383,10 +391,16 @@ static const char usage_message[] =
   "--ifconfig-pool-persist file [seconds] : Persist/unpersist ifconfig-pool\n"
   "                  data to file, at seconds intervals (default=600).\n"
   "                  If seconds=0, file will be treated as read-only.\n"
+  "--ifconfig-ipv6-pool base-IP/bits : set aside an IPv6 network block\n"
+  "                  to be dynamically allocated to connecting clients.\n"
   "--ifconfig-push local remote-netmask : Push an ifconfig option to remote,\n"
   "                  overrides --ifconfig-pool dynamic allocation.\n"
   "                  Only valid in a client-specific config file.\n"
+  "--ifconfig-ipv6-push local/bits remote : Push an ifconfig-ipv6 option to\n"
+  "                  remote, overrides --ifconfig-ipv6-pool allocation.\n"
+  "                  Only valid in a client-specific config file.\n"
   "--iroute network [netmask] : Route subnet to client.\n"
+  "--iroute-ipv6 network/bits : Route IPv6 subnet to client.\n"
   "                  Sets up internal routes only.\n"
   "                  Only valid in a client-specific config file.\n"
   "--disable       : Client is disabled.\n"
@@ -871,6 +885,78 @@ get_ip_addr (const char *ip_string, int msglevel, bool *error)
   return ret;
 }
 
+/* helper: parse a text string containing an IPv6 address + netbits
+ * in "standard format" (2001:dba::/32)
+ * "/nn" is optional, default to /64 if missing
+ *
+ * return true if parsing succeeded, modify *network and *netbits
+ * return address part without "/nn" in *printable_ipv6 (if != NULL)
+ */
+bool
+get_ipv6_addr( const char * prefix_str, struct in6_addr *network,
+	       unsigned int * netbits, char ** printable_ipv6, int msglevel )
+{
+    int rc;
+    char * sep, * endp;
+    int bits;
+    struct in6_addr t_network;
+
+    sep = strchr( prefix_str, '/' );
+    if ( sep == NULL )
+      {
+ 	bits = 64;
+      }
+    else
+      {
+	bits = strtol( sep+1, &endp, 10 );
+	if ( *endp != '\0' || bits < 0 || bits > 128 )
+	  {
+	    msg (msglevel, "IPv6 prefix '%s': invalid '/bits' spec", prefix_str);
+	    return false;
+	  }
+      }
+
+    /* temporary replace '/' in caller-provided string with '\0', otherwise
+     * inet_pton() will refuse prefix string
+     * (alternative would be to strncpy() the prefix to temporary buffer)
+     */
+
+    if ( sep != NULL ) *sep = '\0';
+
+    rc = inet_pton( AF_INET6, prefix_str, &t_network );
+
+    if ( rc == 1 && printable_ipv6 != NULL )
+      {
+	*printable_ipv6 = string_alloc( prefix_str, NULL );
+      }
+
+    if ( sep != NULL ) *sep = '/';
+
+    if ( rc != 1 )
+      {
+	msg (msglevel, "IPv6 prefix '%s': invalid IPv6 address", prefix_str);
+	return false;
+      }
+
+    if ( netbits != NULL )
+      {
+	*netbits = bits;
+      }
+    if ( network != NULL )
+      {
+	*network = t_network;
+      }
+    return true;		/* parsing OK, values set */
+}
+
+static bool ipv6_addr_safe_hexplusbits( const char * ipv6_prefix_spec )
+{
+    struct in6_addr t_addr;
+    unsigned int t_bits;
+
+    return get_ipv6_addr( ipv6_prefix_spec, &t_addr, &t_bits, NULL, M_WARN );
+}
+
 static char *
 string_substitute (const char *src, int from, int to, struct gc_arena *gc)
 {
@@ -989,6 +1075,8 @@ show_p2mp_parms (const struct options *o)
 #if P2MP_SERVER
   msg (D_SHOW_PARMS, "  server_network = %s", print_in_addr_t (o->server_network, 0, &gc));
   msg (D_SHOW_PARMS, "  server_netmask = %s", print_in_addr_t (o->server_netmask, 0, &gc));
+  msg (D_SHOW_PARMS, "  server_network_ipv6 = %s", print_in6_addr (o->server_network_ipv6, 0, &gc) );
+  SHOW_INT (server_netbits_ipv6);
   msg (D_SHOW_PARMS, "  server_bridge_ip = %s", print_in_addr_t (o->server_bridge_ip, 0, &gc));
   msg (D_SHOW_PARMS, "  server_bridge_netmask = %s", print_in_addr_t (o->server_bridge_netmask, 0, &gc));
   msg (D_SHOW_PARMS, "  server_bridge_pool_start = %s", print_in_addr_t (o->server_bridge_pool_start, 0, &gc));
@@ -1009,6 +1097,9 @@ show_p2mp_parms (const struct options *o)
   msg (D_SHOW_PARMS, "  ifconfig_pool_netmask = %s", print_in_addr_t (o->ifconfig_pool_netmask, 0, &gc));
   SHOW_STR (ifconfig_pool_persist_filename);
   SHOW_INT (ifconfig_pool_persist_refresh_freq);
+  SHOW_BOOL (ifconfig_ipv6_pool_defined);
+  msg (D_SHOW_PARMS, "  ifconfig_ipv6_pool_base = %s", print_in6_addr (o->ifconfig_ipv6_pool_base, 0, &gc));
+  SHOW_INT (ifconfig_ipv6_pool_netbits);
   SHOW_INT (n_bcast_buf);
   SHOW_INT (tcp_queue_limit);
   SHOW_INT (real_hash_size);
@@ -1022,6 +1113,9 @@ show_p2mp_parms (const struct options *o)
   SHOW_BOOL (push_ifconfig_defined);
   msg (D_SHOW_PARMS, "  push_ifconfig_local = %s", print_in_addr_t (o->push_ifconfig_local, 0, &gc));
   msg (D_SHOW_PARMS, "  push_ifconfig_remote_netmask = %s", print_in_addr_t (o->push_ifconfig_remote_netmask, 0, &gc));
+  SHOW_BOOL (push_ifconfig_ipv6_defined);
+  msg (D_SHOW_PARMS, "  push_ifconfig_ipv6_local = %s/%d", print_in6_addr (o->push_ifconfig_ipv6_local, 0, &gc), o->push_ifconfig_ipv6_netbits );
+  msg (D_SHOW_PARMS, "  push_ifconfig_ipv6_remote = %s", print_in6_addr (o->push_ifconfig_ipv6_remote, 0, &gc));
   SHOW_BOOL (enable_c2c);
   SHOW_BOOL (duplicate_cn);
   SHOW_INT (cf_max);
@@ -1076,6 +1170,25 @@ option_iroute (struct options *o,
   o->iroutes = ir;
 }
 
+static void
+option_iroute_ipv6 (struct options *o,
+	       const char *prefix_str,
+	       int msglevel)
+{
+  struct iroute_ipv6 *ir;
+
+  ALLOC_OBJ_GC (ir, struct iroute_ipv6, &o->gc);
+
+  if ( get_ipv6_addr (prefix_str, &ir->network, &ir->netbits, NULL, msglevel ) < 0 )
+    {
+      msg (msglevel, "in --iroute-ipv6 %s: Bad IPv6 prefix specification",
+	   prefix_str);
+      return;
+    }
+
+  ir->next = o->iroutes_ipv6;
+  o->iroutes_ipv6 = ir;
+}
 #endif /* P2MP_SERVER */
 #endif /* P2MP */
 
@@ -1113,6 +1226,13 @@ rol_check_alloc (struct options *options)
     options->routes = new_route_option_list (options->max_routes, &options->gc);
 }
 
+void
+rol6_check_alloc (struct options *options)
+{
+  if (!options->routes_ipv6)
+    options->routes_ipv6 = new_route_ipv6_option_list (options->max_routes, &options->gc);
+}
+
 #ifdef ENABLE_DEBUG
 static void
 show_connection_entry (const struct connection_entry *o)
@@ -1203,6 +1323,9 @@ show_settings (const struct options *o)
   SHOW_STR (ifconfig_remote_netmask);
   SHOW_BOOL (ifconfig_noexec);
   SHOW_BOOL (ifconfig_nowarn);
+  SHOW_STR (ifconfig_ipv6_local);
+  SHOW_INT (ifconfig_ipv6_netbits);
+  SHOW_STR (ifconfig_ipv6_remote);
 
 #ifdef HAVE_GETTIMEOFDAY
   SHOW_INT (shaper);
@@ -1863,8 +1986,10 @@ options_postprocess_verify_ce (const struct options *options, const struct conne
       if (options->connection_list)
 	msg (M_USAGE, "<connection> cannot be used with --mode server");
 #endif
+#if 0
       if (options->tun_ipv6)
 	msg (M_USAGE, "--tun-ipv6 cannot be used with --mode server");
+#endif
       if (options->shaper)
 	msg (M_USAGE, "--shaper cannot be used with --mode server");
       if (options->inetd)
@@ -1889,6 +2014,11 @@ options_postprocess_verify_ce (const struct options *options, const struct conne
 	msg (M_USAGE, "--up-delay cannot be used with --mode server");
       if (!options->ifconfig_pool_defined && options->ifconfig_pool_persist_filename)
 	msg (M_USAGE, "--ifconfig-pool-persist must be used with --ifconfig-pool");
+      if (options->ifconfig_ipv6_pool_defined && !options->ifconfig_ipv6_local )
+	msg (M_USAGE, "--ifconfig-ipv6-pool needs --ifconfig-ipv6");
+      if (options->ifconfig_ipv6_local && !options->tun_ipv6 )
+	msg (M_INFO, "Warning: --ifconfig-ipv6 without --tun-ipv6 will not do IPv6");
+
       if (options->auth_user_pass_file)
 	msg (M_USAGE, "--auth-user-pass cannot be used with --mode server (it should be used on the client side only)");
       if (options->ccd_exclusive && !options->client_config_dir)
@@ -1920,6 +2050,8 @@ options_postprocess_verify_ce (const struct options *options, const struct conne
        */
       if (options->ifconfig_pool_defined || options->ifconfig_pool_persist_filename)
 	msg (M_USAGE, "--ifconfig-pool/--ifconfig-pool-persist requires --mode server");
+      if (options->ifconfig_ipv6_pool_defined)
+	msg (M_USAGE, "--ifconfig-ipv6-pool requires --mode server");
       if (options->real_hash_size != defaults.real_hash_size
 	  || options->virtual_hash_size != defaults.virtual_hash_size)
 	msg (M_USAGE, "--hash-size requires --mode server");
@@ -2461,6 +2593,8 @@ options_string (const struct options *o,
 		     o->topology,
 		     o->ifconfig_local,
 		     o->ifconfig_remote_netmask,
+		     o->ifconfig_ipv6_local,
+		     o->ifconfig_ipv6_remote,
 		     (in_addr_t)0,
 		     (in_addr_t)0,
 		     false,
@@ -3786,6 +3920,30 @@ add_option (struct options *options,
 	  goto err;
 	}
     }
+  else if (streq (p[0], "ifconfig-ipv6") && p[1] && p[2] )
+    {
+      unsigned int netbits;
+      char * ipv6_local;
+	
+      VERIFY_PERMISSION (OPT_P_UP);
+      if ( get_ipv6_addr( p[1], NULL, &netbits, &ipv6_local, msglevel ) &&
+           ipv6_addr_safe( p[2] ) )
+        {
+	  if ( netbits < 64 || netbits > 124 )
+	    {
+	      msg( msglevel, "ifconfig-ipv6: /netbits must be between 64 and 124, not '/%d'", netbits );
+	      goto err;
+	    }
+	  options->ifconfig_ipv6_local = ipv6_local;
+	  options->ifconfig_ipv6_netbits = netbits;
+	  options->ifconfig_ipv6_remote = p[2];
+        }
+      else
+	{
+	  msg (msglevel, "ifconfig-ipv6 parms '%s' and '%s' must be valid addresses", p[1], p[2]);
+	  goto err;
+	}
+    }
   else if (streq (p[0], "ifconfig-noexec"))
     {
       VERIFY_PERMISSION (OPT_P_UP);
@@ -4586,6 +4744,26 @@ add_option (struct options *options,
 	}
       add_route_to_option_list (options->routes, p[1], p[2], p[3], p[4]);
     }
+  else if (streq (p[0], "route-ipv6") && p[1])
+    {
+      VERIFY_PERMISSION (OPT_P_ROUTE);
+      rol6_check_alloc (options);
+      if (pull_mode)
+	{
+	  if (!ipv6_addr_safe_hexplusbits (p[1]))
+	    {
+	      msg (msglevel, "route-ipv6 parameter network/IP '%s' must be a valid address", p[1]);
+	      goto err;
+	    }
+	  if (p[2] && !ipv6_addr_safe (p[2]))
+	    {
+	      msg (msglevel, "route-ipv6 parameter gateway '%s' must be a valid address", p[2]);
+	      goto err;
+	    }
+	  /* p[3] is metric, if present */
+	}
+      add_route_ipv6_to_option_list (options->routes_ipv6, p[1], p[2], p[3]);
+    }
   else if (streq (p[0], "max-routes") && p[1])
     {
       int max_routes;
@@ -4797,6 +4975,33 @@ add_option (struct options *options,
 	    }
 	}
     }
+  else if (streq (p[0], "server-ipv6") && p[1] )
+    {
+      const int lev = M_WARN;
+      struct in6_addr network;
+      unsigned int netbits = 0;
+
+      VERIFY_PERMISSION (OPT_P_GENERAL);
+      if ( ! get_ipv6_addr (p[1], &network, &netbits, NULL, lev) )
+	{
+	  msg (msglevel, "error parsing --server-ipv6 parameter");
+	  goto err;
+	}
+      if ( netbits != 64 )
+	{
+	  msg( msglevel, "--server-ipv6 settings: only /64 supported right now (not /%d)", netbits );
+	  goto err;
+	}
+      options->server_ipv6_defined = true;
+      options->server_network_ipv6 = network;
+      options->server_netbits_ipv6 = netbits;
+
+      if (p[2])		/* no "nopool" options or similar for IPv6 */
+	{
+	  msg (msglevel, "error parsing --server-ipv6: %s is not a recognized flag", p[3]);
+	  goto err;
+	}
+    }
   else if (streq (p[0], "server-bridge") && p[1] && p[2] && p[3] && p[4])
     {
       const int lev = M_WARN;
@@ -4881,6 +5086,28 @@ add_option (struct options *options,
       VERIFY_PERMISSION (OPT_P_GENERAL);
       options->topology = TOP_P2P;
     }
+  else if (streq (p[0], "ifconfig-ipv6-pool") && p[1] )
+    {
+      const int lev = M_WARN;
+      struct in6_addr network;
+      unsigned int netbits = 0;
+
+      VERIFY_PERMISSION (OPT_P_GENERAL);
+      if ( ! get_ipv6_addr (p[1], &network, &netbits, NULL, lev ) )
+	{
+	  msg (msglevel, "error parsing --ifconfig-ipv6-pool parameters");
+	  goto err;
+	}
+      if ( netbits != 64 )
+	{
+	  msg( msglevel, "--ifconfig-ipv6-pool settings: only /64 supported right now (not /%d)", netbits );
+	  goto err;
+	}
+
+      options->ifconfig_ipv6_pool_defined = true;
+      options->ifconfig_ipv6_pool_base = network;
+      options->ifconfig_ipv6_pool_netbits = netbits;
+    }
   else if (streq (p[0], "hash-size") && p[1] && p[2])
     {
       int real, virtual;
@@ -5076,6 +5303,11 @@ add_option (struct options *options,
 	}
       option_iroute (options, p[1], netmask, msglevel);
     }
+  else if (streq (p[0], "iroute-ipv6") && p[1])
+    {
+      VERIFY_PERMISSION (OPT_P_INSTANCE);
+      option_iroute_ipv6 (options, p[1], msglevel);
+    }
   else if (streq (p[0], "ifconfig-push") && p[1] && p[2])
     {
       in_addr_t local, remote_netmask;
@@ -5114,6 +5346,43 @@ add_option (struct options *options,
 	  goto err;
 	}
     }
+  else if (streq (p[0], "ifconfig-ipv6-push") && p[1] )
+    {
+      struct in6_addr local, remote;
+      unsigned int netbits;
+
+      VERIFY_PERMISSION (OPT_P_INSTANCE);
+
+      if ( ! get_ipv6_addr( p[1], &local, &netbits, NULL, msglevel ) )
+	{
+	  msg (msglevel, "cannot parse --ifconfig-ipv6-push addresses");
+	  goto err;
+	}
+
+      if ( p[2] )
+	{
+	  if ( !get_ipv6_addr( p[2], &remote, NULL, NULL, msglevel ) )
+	    {
+	      msg( msglevel, "cannot parse --ifconfig-ipv6-push addresses");
+	      goto err;
+	    }
+	}
+      else
+	{
+	  if ( ! options->ifconfig_ipv6_local ||
+	       ! get_ipv6_addr( options->ifconfig_ipv6_local, &remote, 
+				NULL, NULL, msglevel ) )
+	    {
+	      msg( msglevel, "second argument to --ifconfig-ipv6-push missing and no global --ifconfig-ipv6 address set");
+	      goto err;
+	    }
+	}
+
+      options->push_ifconfig_ipv6_defined = true;
+      options->push_ifconfig_ipv6_local = local;
+      options->push_ifconfig_ipv6_netbits = netbits;
+      options->push_ifconfig_ipv6_remote = remote;
+    }
   else if (streq (p[0], "disable"))
     {
       VERIFY_PERMISSION (OPT_P_INSTANCE);
diff --git a/options.h b/options.h
index dd49355..3b01597 100644
--- a/options.h
+++ b/options.h
@@ -205,6 +205,9 @@ struct options
   int topology; /* one of the TOP_x values from proto.h */
   const char *ifconfig_local;
   const char *ifconfig_remote_netmask;
+  const char *ifconfig_ipv6_local;
+  int         ifconfig_ipv6_netbits;
+  const char *ifconfig_ipv6_remote;
   bool ifconfig_noexec;
   bool ifconfig_nowarn;
 #ifdef HAVE_GETTIMEOFDAY
@@ -326,6 +329,7 @@ struct options
   bool route_delay_defined;
   int max_routes;
   struct route_option_list *routes;
+  struct route_ipv6_option_list *routes_ipv6;			/* IPv6 */
   bool route_nopull;
   bool route_gateway_via_dhcp;
   bool allow_pull_fqdn; /* as a client, allow server to push a FQDN for certain parameters */
@@ -363,6 +367,9 @@ struct options
   bool server_defined;
   in_addr_t server_network;
   in_addr_t server_netmask;
+  bool server_ipv6_defined;				/* IPv6 */
+  struct in6_addr server_network_ipv6;			/* IPv6 */
+  unsigned int    server_netbits_ipv6;			/* IPv6 */
 
 # define SF_NOPOOL (1<<0)
 # define SF_TCP_NODELAY_HELPER (1<<1)
@@ -384,6 +391,11 @@ struct options
   in_addr_t ifconfig_pool_netmask;
   const char *ifconfig_pool_persist_filename;
   int ifconfig_pool_persist_refresh_freq;
+
+  bool   ifconfig_ipv6_pool_defined;                   /* IPv6 */
+  struct in6_addr ifconfig_ipv6_pool_base;             /* IPv6 */
+  int    ifconfig_ipv6_pool_netbits;                   /* IPv6 */
+
   int real_hash_size;
   int virtual_hash_size;
   const char *client_connect_script;
@@ -395,12 +407,17 @@ struct options
   int n_bcast_buf;
   int tcp_queue_limit;
   struct iroute *iroutes;
+  struct iroute_ipv6 *iroutes_ipv6;                    /* IPv6 */
   bool push_ifconfig_defined;
   in_addr_t push_ifconfig_local;
   in_addr_t push_ifconfig_remote_netmask;
   bool push_ifconfig_constraint_defined;
   in_addr_t push_ifconfig_constraint_network;
   in_addr_t push_ifconfig_constraint_netmask;
+  bool            push_ifconfig_ipv6_defined;          /* IPv6 */
+  struct in6_addr push_ifconfig_ipv6_local;            /* IPv6 */
+  int            push_ifconfig_ipv6_netbits;           /* IPv6 */
+  struct in6_addr push_ifconfig_ipv6_remote;           /* IPv6 */
   bool enable_c2c;
   bool duplicate_cn;
   int cf_max;
@@ -723,6 +740,10 @@ void options_string_import (struct options *options,
 			    unsigned int *option_types_found,
 			    struct env_set *es);
 
+bool get_ipv6_addr( const char * prefix_str, struct in6_addr *network,
+		    unsigned int * netbits, char ** printable_ipv6, 
+		    int msglevel );
+
 /*
  * inline functions
  */
diff --git a/pool.c b/pool.c
index 84333df..60dc520 100644
--- a/pool.c
+++ b/pool.c
@@ -132,7 +132,10 @@ ifconfig_pool_verify_range (const int msglevel, const in_addr_t start, const in_
 }
 
 struct ifconfig_pool *
-ifconfig_pool_init (int type, in_addr_t start, in_addr_t end, const bool duplicate_cn)
+ifconfig_pool_init (int type, in_addr_t start, in_addr_t end, 
+		    const bool duplicate_cn,
+		    const bool ipv6_pool, const struct in6_addr ipv6_base, 
+		    const int ipv6_netbits )
 {
   struct gc_arena gc = gc_new ();
   struct ifconfig_pool *pool = NULL;
@@ -157,11 +160,31 @@ ifconfig_pool_init (int type, in_addr_t start, in_addr_t end, const bool duplica
       ASSERT (0);
     }
 
+  /* IPv6 pools are always "INDIV" type */
+  pool->ipv6 = ipv6_pool;
+
+  if ( pool->ipv6 )
+    {
+      pool->base_ipv6 = ipv6_base;
+      pool->size_ipv6 = ipv6_netbits>96? ( 1<<(128-ipv6_netbits) ) 
+				       : IFCONFIG_POOL_MAX;
+
+      msg( D_IFCONFIG_POOL, "IFCONFIG POOL IPv6: (IPv4) size=%d, size_ipv6=%d, netbits=%d, base_ipv6=%s",
+			    pool->size, pool->size_ipv6, ipv6_netbits,
+			    print_in6_addr( pool->base_ipv6, 0, &gc ));
+
+      /* the current code is very simple and assumes that the IPv6
+       * pool is at least as big as the IPv4 pool, and we don't need
+       * to do separate math etc. for IPv6
+       */
+      ASSERT( pool->size < pool->size_ipv6 );
+    }
+
   ALLOC_ARRAY_CLEAR (pool->list, struct ifconfig_pool_entry, pool->size);
 
-  msg (D_IFCONFIG_POOL, "IFCONFIG POOL: base=%s size=%d",
+  msg (D_IFCONFIG_POOL, "IFCONFIG POOL: base=%s size=%d, ipv6=%d",
        print_in_addr_t (pool->base, 0, &gc),
-       pool->size);
+       pool->size, pool->ipv6 );
 
   gc_free (&gc);
   return pool;
@@ -181,7 +204,7 @@ ifconfig_pool_free (struct ifconfig_pool *pool)
 }
 
 ifconfig_pool_handle
-ifconfig_pool_acquire (struct ifconfig_pool *pool, in_addr_t *local, in_addr_t *remote, const char *common_name)
+ifconfig_pool_acquire (struct ifconfig_pool *pool, in_addr_t *local, in_addr_t *remote, struct in6_addr *remote_ipv6, const char *common_name)
 {
   int i;
 
@@ -214,6 +237,12 @@ ifconfig_pool_acquire (struct ifconfig_pool *pool, in_addr_t *local, in_addr_t *
 	default:
 	  ASSERT (0);
 	}
+
+      /* IPv6 pools are always INDIV (--linear) */
+      if ( pool->ipv6 && remote_ipv6 )
+	{
+	  *remote_ipv6 = add_in6_addr( pool->base_ipv6, i );
+	}
     }
   return i;
 }
@@ -288,6 +317,19 @@ ifconfig_pool_handle_to_ip_base (const struct ifconfig_pool* pool, ifconfig_pool
   return ret;
 }
 
+static struct in6_addr
+ifconfig_pool_handle_to_ipv6_base (const struct ifconfig_pool* pool, ifconfig_pool_handle hand)
+{
+  struct in6_addr ret = in6addr_any;
+
+  /* IPv6 pools are always INDIV (--linear) */
+  if (hand >= 0 && hand < pool->size_ipv6 )
+    {
+      ret = add_in6_addr( pool->base_ipv6, hand );
+    }
+  return ret;
+}
+
 static void
 ifconfig_pool_set (struct ifconfig_pool* pool, const char *cn, const in_addr_t addr, const bool fixed)
 {
@@ -317,9 +359,20 @@ ifconfig_pool_list (const struct ifconfig_pool* pool, struct status_output *out)
 	  if (e->common_name)
 	    {
 	      const in_addr_t ip = ifconfig_pool_handle_to_ip_base (pool, i);
-	      status_printf (out, "%s,%s",
-			     e->common_name,
-			     print_in_addr_t (ip, 0, &gc));
+	      if ( pool->ipv6 )
+		{
+		  struct in6_addr ip6 = ifconfig_pool_handle_to_ipv6_base (pool, i);
+		  status_printf (out, "%s,%s,%s",
+				 e->common_name,
+				 print_in_addr_t (ip, 0, &gc),
+				 print_in6_addr (ip6, 0, &gc));
+		}
+	      else
+		{
+		  status_printf (out, "%s,%s",
+				 e->common_name,
+				 print_in_addr_t (ip, 0, &gc));
+		}
 	    }
 	}
       gc_free (&gc);
@@ -409,6 +462,9 @@ ifconfig_pool_read (struct ifconfig_pool_persist *persist, struct ifconfig_pool
 	      int c = *BSTR(&in);
 	      if (c == '#' || c == ';')
 		continue;
+	      msg( M_INFO, "ifconfig_pool_read(), in='%s', TODO: IPv6",
+				BSTR(&in) );
+
 	      if (buf_parse (&in, ',', cn_buf, buf_size)
 		  && buf_parse (&in, ',', ip_buf, buf_size))
 		{
@@ -416,6 +472,7 @@ ifconfig_pool_read (struct ifconfig_pool_persist *persist, struct ifconfig_pool
 		  const in_addr_t addr = getaddr (GETADDR_HOST_ORDER, ip_buf, 0, &succeeded, NULL);
 		  if (succeeded)
 		    {
+		      msg( M_INFO, "succeeded -> ifconfig_pool_set()");
 		      ifconfig_pool_set (pool, cn_buf, addr, persist->fixed);
 		    }
 		}
@@ -471,7 +528,7 @@ ifconfig_pool_test (in_addr_t start, in_addr_t end)
 #else
       cn = buf;
 #endif
-      h = ifconfig_pool_acquire (p, &local, &remote, cn);
+      h = ifconfig_pool_acquire (p, &local, &remote, NULL, cn);
       if (h < 0)
 	break;
       msg (M_INFO | M_NOPREFIX, "IFCONFIG_POOL TEST pass 1: l=%s r=%s cn=%s",
@@ -506,7 +563,7 @@ ifconfig_pool_test (in_addr_t start, in_addr_t end)
 #else
       cn = buf;
 #endif
-      h = ifconfig_pool_acquire (p, &local, &remote, cn);
+      h = ifconfig_pool_acquire (p, &local, &remote, NULL, cn);
       if (h < 0)
 	break;
       msg (M_INFO | M_NOPREFIX, "IFCONFIG_POOL TEST pass 3: l=%s r=%s cn=%s",
diff --git a/pool.h b/pool.h
index 81264a9..fc9d6ab 100644
--- a/pool.h
+++ b/pool.h
@@ -52,6 +52,9 @@ struct ifconfig_pool
   int size;
   int type;
   bool duplicate_cn;
+  bool ipv6;
+  struct in6_addr base_ipv6;
+  unsigned int size_ipv6;
   struct ifconfig_pool_entry *list;
 };
 
@@ -63,13 +66,13 @@ struct ifconfig_pool_persist
 
 typedef int ifconfig_pool_handle;
 
-struct ifconfig_pool *ifconfig_pool_init (int type, in_addr_t start, in_addr_t end, const bool duplicate_cn);
+struct ifconfig_pool *ifconfig_pool_init (int type, in_addr_t start, in_addr_t end, const bool duplicate_cn, const bool ipv6_pool, const struct in6_addr ipv6_base, const int ipv6_netbits );
 
 void ifconfig_pool_free (struct ifconfig_pool *pool);
 
 bool ifconfig_pool_verify_range (const int msglevel, const in_addr_t start, const in_addr_t end);
 
-ifconfig_pool_handle ifconfig_pool_acquire (struct ifconfig_pool *pool, in_addr_t *local, in_addr_t *remote, const char *common_name);
+ifconfig_pool_handle ifconfig_pool_acquire (struct ifconfig_pool *pool, in_addr_t *local, in_addr_t *remote, struct in6_addr *remote_ipv6, const char *common_name);
 
 bool ifconfig_pool_release (struct ifconfig_pool* pool, ifconfig_pool_handle hand, const bool hard);
 
diff --git a/proto.h b/proto.h
index 55f0832..b8e8997 100644
--- a/proto.h
+++ b/proto.h
@@ -108,6 +108,21 @@ struct openvpn_iphdr {
 };
 
 /*
+ * IPv6 header
+ */
+struct openvpn_ipv6hdr {
+        uint8_t		version_prio;
+        uint8_t		flow_lbl[3];
+        uint16_t	payload_len;
+        uint8_t		nexthdr;
+        uint8_t		hop_limit;
+
+        struct  in6_addr        saddr;
+        struct  in6_addr        daddr;
+};
+
+
+/*
  * UDP header
  */
 struct openvpn_udphdr {
diff --git a/push.c b/push.c
index 08c7f99..1fd8bea 100644
--- a/push.c
+++ b/push.c
@@ -189,8 +189,26 @@ send_push_reply (struct context *c)
   const int safe_cap = BCAP (&buf) - extra;
   bool push_sent = false;
 
+  msg( M_INFO, "send_push_reply(): safe_cap=%d", safe_cap );
+
   buf_printf (&buf, "%s", cmd);
 
+  if ( c->c2.push_ifconfig_ipv6_defined )
+    {
+      /* IPv6 is put into buffer first, could be lengthy */
+      /* TODO: push "/netbits" as well, to allow non-/64 subnet sizes
+       *       (needs changes in options.c, options.h, and other places)
+       */
+      buf_printf( &buf, ",ifconfig-ipv6 %s %s",
+		    print_in6_addr( c->c2.push_ifconfig_ipv6_local, 0, &gc),
+		    print_in6_addr( c->c2.push_ifconfig_ipv6_remote, 0, &gc) );
+      if (BLEN (&buf) >= safe_cap)
+	{
+	  msg (M_WARN, "--push ifconfig-ipv6 option is too long");
+	  goto fail;
+	}
+    }
+
   while (e)
     {
       if (e->enable)
diff --git a/route.c b/route.c
index b5092fe..7c81f75 100644
--- a/route.c
+++ b/route.c
@@ -35,6 +35,7 @@
 #include "socket.h"
 #include "manage.h"
 #include "win32.h"
+#include "options.h"
 
 #include "memdbg.h"
 
@@ -68,6 +69,15 @@ new_route_option_list (const int max_routes, struct gc_arena *a)
   return ret;
 }
 
+struct route_ipv6_option_list *
+new_route_ipv6_option_list (const int max_routes, struct gc_arena *a)
+{
+  struct route_ipv6_option_list *ret;
+  ALLOC_VAR_ARRAY_CLEAR_GC (ret, struct route_ipv6_option_list, struct route_ipv6_option, max_routes, a);
+  ret->capacity = max_routes;
+  return ret;
+}
+
 struct route_option_list *
 clone_route_option_list (const struct route_option_list *src, struct gc_arena *a)
 {
@@ -95,6 +105,15 @@ new_route_list (const int max_routes, struct gc_arena *a)
   return ret;
 }
 
+struct route_ipv6_list *
+new_route_ipv6_list (const int max_routes, struct gc_arena *a)
+{
+  struct route_ipv6_list *ret;
+  ALLOC_VAR_ARRAY_CLEAR_GC (ret, struct route_ipv6_list, struct route_ipv6, max_routes, a);
+  ret->capacity = max_routes;
+  return ret;
+}
+
 static const char *
 route_string (const struct route *r, struct gc_arena *gc)
 {
@@ -311,6 +330,68 @@ init_route (struct route *r,
   return false;
 }
 
+static bool
+init_route_ipv6 (struct route_ipv6 *r6,
+	         const struct route_ipv6_option *r6o,
+	         const struct route_ipv6_list *rl6 )
+{
+  r6->option = r6o;
+  r6->defined = false;
+
+  if ( !get_ipv6_addr( r6o->prefix, &r6->network, &r6->netbits, NULL, M_WARN ))
+    goto fail;
+
+  /* gateway */
+  if (is_route_parm_defined (r6o->gateway))
+    {
+      if ( inet_pton( AF_INET6, r6o->gateway, &r6->gateway ) != 1 )
+        {
+	  msg( M_WARN, PACKAGE_NAME "ROUTE6: cannot parse gateway spec '%s'", r6o->gateway );
+        }
+    }
+  else if (rl6->remote_endpoint_defined)
+    {
+      r6->gateway = rl6->remote_endpoint_ipv6;
+    }
+  else
+    {
+      msg (M_WARN, PACKAGE_NAME " ROUTE6: " PACKAGE_NAME " needs a gateway parameter for a --route-ipv6 option and no default was specified by either --route-ipv6-gateway or --ifconfig-ipv6 options");
+      goto fail;
+    }
+
+  /* metric */
+
+  r6->metric_defined = false;
+  r6->metric = 0;
+  if (is_route_parm_defined (r6o->metric))
+    {
+      r6->metric = atoi (r6o->metric);
+      if (r6->metric < 0)
+	{
+	  msg (M_WARN, PACKAGE_NAME " ROUTE: route metric for network %s (%s) must be >= 0",
+	       r6o->prefix,
+	       r6o->metric);
+	  goto fail;
+	}
+      r6->metric_defined = true;
+    }
+  else if (rl6->default_metric_defined)
+    {
+      r6->metric = rl6->default_metric;
+      r6->metric_defined = true;
+    }
+
+  r6->defined = true;
+
+  return true;
+
+ fail:
+  msg (M_WARN, PACKAGE_NAME " ROUTE: failed to parse/resolve route for host/network: %s",
+       r6o->prefix);
+  r6->defined = false;
+  return false;
+}
+
 void
 add_route_to_option_list (struct route_option_list *l,
 			  const char *network,
@@ -331,6 +412,23 @@ add_route_to_option_list (struct route_option_list *l,
 }
 
 void
+add_route_ipv6_to_option_list (struct route_ipv6_option_list *l,
+			  const char *prefix,
+			  const char *gateway,
+			  const char *metric)
+{
+  struct route_ipv6_option *ro;
+  if (l->n >= l->capacity)
+    msg (M_FATAL, PACKAGE_NAME " ROUTE: cannot add more than %d IPv6 routes -- please increase the max-routes option in the client configuration file",
+	 l->capacity);
+  ro = &l->routes_ipv6[l->n];
+  ro->prefix = prefix;
+  ro->gateway = gateway;
+  ro->metric = metric;
+  ++l->n;
+}
+
+void
 clear_route_list (struct route_list *rl)
 {
   const int capacity = rl->capacity;
@@ -340,6 +438,15 @@ clear_route_list (struct route_list *rl)
 }
 
 void
+clear_route_ipv6_list (struct route_ipv6_list *rl6)
+{
+  const int capacity = rl6->capacity;
+  const size_t rl6_size = array_mult_safe (sizeof(struct route_ipv6), capacity, sizeof(struct route_ipv6_list));
+  memset(rl6, 0, rl6_size);
+  rl6->capacity = capacity;
+}
+
+void
 route_list_add_default_gateway (struct route_list *rl,
 				struct env_set *es,
 				const in_addr_t addr)
@@ -469,6 +576,72 @@ init_route_list (struct route_list *rl,
   return ret;
 }
 
+bool
+init_route_ipv6_list (struct route_ipv6_list *rl6,
+		 const struct route_ipv6_option_list *opt6,
+		 const char *remote_endpoint,
+		 int default_metric,
+		 struct env_set *es)
+{
+  struct gc_arena gc = gc_new ();
+  bool ret = true;
+
+  clear_route_ipv6_list (rl6);
+
+  rl6->flags = opt6->flags;
+
+  if (default_metric)
+    {
+      rl6->default_metric = default_metric;
+      rl6->default_metric_defined = true;
+    }
+
+  /* "default_gateway" is stuff for "redirect-gateway", which we don't
+   * do for IPv6 yet -> TODO
+   */
+    {
+      dmsg (D_ROUTE, "ROUTE6: default_gateway=UNDEF");
+    }
+
+  if ( is_route_parm_defined( remote_endpoint ))
+    {
+      if ( inet_pton( AF_INET6, remote_endpoint, 
+			&rl6->remote_endpoint_ipv6) == 1 )
+        {
+	  rl6->remote_endpoint_defined = true;
+        }
+      else
+	{
+	  msg (M_WARN, PACKAGE_NAME " ROUTE: failed to parse/resolve default gateway: %s", remote_endpoint);
+          ret = false;
+	}
+    }
+  else
+    rl6->remote_endpoint_defined = false;
+
+
+  if (!(opt6->n >= 0 && opt6->n <= rl6->capacity))
+    msg (M_FATAL, PACKAGE_NAME " ROUTE6: (init) number of route options (%d) is greater than route list capacity (%d)", opt6->n, rl6->capacity);
+
+  /* parse the routes from opt to rl6 */
+  {
+    int i, j = 0;
+    for (i = 0; i < opt6->n; ++i)
+      {
+	if (!init_route_ipv6 (&rl6->routes_ipv6[j],
+			      &opt6->routes_ipv6[i],
+			      rl6 ))
+	  ret = false;
+	else
+	  ++j;
+      }
+    rl6->n = j;
+  }
+
+  gc_free (&gc);
+  return ret;
+}
+
 static void
 add_route3 (in_addr_t network,
 	    in_addr_t netmask,
@@ -704,10 +877,13 @@ undo_redirect_default_route_to_vpn (struct route_list *rl, const struct tuntap *
 }
 
 void
-add_routes (struct route_list *rl, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
+add_routes (struct route_list *rl, struct route_ipv6_list *rl6,
+	    const struct tuntap *tt, unsigned int flags, const struct env_set *es)
 {
-  redirect_default_route_to_vpn (rl, tt, flags, es);
-  if (!rl->routes_added)
+  if (rl) 
+      redirect_default_route_to_vpn (rl, tt, flags, es);
+
+  if (rl && !rl->routes_added)
     {
       int i;
 
@@ -732,12 +908,27 @@ add_routes (struct route_list *rl, const struct tuntap *tt, unsigned int flags,
 	}
       rl->routes_added = true;
     }
+
+  if (rl6 && !rl6->routes_added)
+    {
+      int i;
+
+      for (i = 0; i < rl6->n; ++i)
+	{
+	  struct route_ipv6 *r = &rl6->routes_ipv6[i];
+	  if (flags & ROUTE_DELETE_FIRST)
+	    delete_route_ipv6 (r, tt, flags, es);
+	  add_route_ipv6 (r, tt, flags, es);
+	}
+      rl6->routes_added = true;
+    }
 }
 
 void
-delete_routes (struct route_list *rl, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
+delete_routes (struct route_list *rl, struct route_ipv6_list *rl6,
+	       const struct tuntap *tt, unsigned int flags, const struct env_set *es)
 {
-  if (rl->routes_added)
+  if (rl && rl->routes_added)
     {
       int i;
       for (i = rl->n - 1; i >= 0; --i)
@@ -747,9 +938,28 @@ delete_routes (struct route_list *rl, const struct tuntap *tt, unsigned int flag
 	}
       rl->routes_added = false;
     }
-  undo_redirect_default_route_to_vpn (rl, tt, flags, es);
 
-  clear_route_list (rl);
+  if ( rl )
+    {
+      undo_redirect_default_route_to_vpn (rl, tt, flags, es);
+      clear_route_list (rl);
+    }
+
+  if ( rl6 && rl6->routes_added )
+    {
+      int i;
+      for (i = rl6->n - 1; i >= 0; --i)
+	{
+	  const struct route_ipv6 *r6 = &rl6->routes_ipv6[i];
+	  delete_route_ipv6 (r6, tt, flags, es);
+	}
+      rl6->routes_added = false;
+    }
+
+  if ( rl6 )
+    {
+      clear_route_ipv6_list (rl6);
+    }
 }
 
 #ifdef ENABLE_DEBUG
@@ -832,6 +1042,34 @@ setenv_routes (struct env_set *es, const struct route_list *rl)
     setenv_route (es, &rl->routes[i], i + 1);
 }
 
+static void
+setenv_route_ipv6 (struct env_set *es, const struct route_ipv6 *r6, int i)
+{
+  struct gc_arena gc = gc_new ();
+  if (r6->defined)
+    {
+      struct buffer name1 = alloc_buf_gc( 256, &gc );
+      struct buffer val = alloc_buf_gc( 256, &gc );
+      struct buffer name2 = alloc_buf_gc( 256, &gc );
+
+      buf_printf( &name1, "route_ipv6_network_%d", i );
+      buf_printf( &val, "%s/%d", print_in6_addr( r6->network, 0, &gc ),
+				 r6->netbits );
+      setenv_str( es, BSTR(&name1), BSTR(&val) );
+
+      buf_printf( &name2, "route_ipv6_gateway_%d", i );
+      setenv_str( es, BSTR(&name2), print_in6_addr( r6->gateway, 0, &gc ));
+    }
+  gc_free (&gc);
+}
+void
+setenv_routes_ipv6 (struct env_set *es, const struct route_ipv6_list *rl6)
+{
+  int i;
+  for (i = 0; i < rl6->n; ++i)
+    setenv_route_ipv6 (es, &rl6->routes_ipv6[i], i + 1);
+}
+
 void
 add_route (struct route *r, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
 {
@@ -1025,6 +1263,187 @@ add_route (struct route *r, const struct tuntap *tt, unsigned int flags, const s
   gc_free (&gc);
 }
 
+
+static const char * 
+print_in6_addr_netbits_only( struct in6_addr network_copy, int netbits, 
+                             struct gc_arena * gc)
+{
+  /* clear host bit parts of route 
+   * (needed if routes are specified improperly, or if we need to 
+   * explicitely setup/clear the "connected" network routes on some OSes)
+   */
+  int byte = 15;
+  int bits_to_clear = 128 - netbits;
+
+  while( byte >= 0 && bits_to_clear > 0 )
+    {
+      if ( bits_to_clear >= 8 )
+	{ network_copy.s6_addr[byte--] = 0; bits_to_clear -= 8; }
+      else
+	{ network_copy.s6_addr[byte--] &= (~0 << bits_to_clear); bits_to_clear = 0; }
+    }
+
+  return print_in6_addr( network_copy, 0, gc);
+}
+
+void
+add_route_ipv6 (struct route_ipv6 *r6, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
+{
+  struct gc_arena gc;
+  struct argv argv;
+
+  const char *network;
+  const char *gateway;
+  bool status = false;
+  const char *device = tt->actual_name;
+
+  if (!r6->defined)
+    return;
+
+  gc_init (&gc);
+  argv_init (&argv);
+
+  network = print_in6_addr_netbits_only( r6->network, r6->netbits, &gc);
+  gateway = print_in6_addr( r6->gateway, 0, &gc);
+
+  if ( !tt->ipv6 )
+    {
+      msg( M_INFO, "add_route_ipv6(): not adding %s/%d, no IPv6 on if %s",
+		    network, r6->netbits, device );
+      return;
+    }
+
+  msg( M_INFO, "add_route_ipv6(%s/%d -> %s metric %d) dev %s",
+		network, r6->netbits, gateway, r6->metric, device );
+
+  /*
+   * Filter out routes which are essentially no-ops
+   * (not currently done for IPv6)
+   */
+
+#if defined(TARGET_LINUX)
+#ifdef CONFIG_FEATURE_IPROUTE
+  argv_printf (&argv, "%s -6 route add %s/%d dev %s",
+  	      iproute_path,
+	      network,
+	      r6->netbits,
+	      device);
+  if (r6->metric_defined)
+    argv_printf_cat (&argv, " metric %d", r6->metric);
+
+#else
+  argv_printf (&argv, "%s -A inet6 add %s/%d dev %s",
+		ROUTE_PATH,
+	      network,
+	      r6->netbits,
+	      device);
+  if (r6->metric_defined)
+    argv_printf_cat (&argv, " metric %d", r6->metric);
+#endif  /*CONFIG_FEATURE_IPROUTE*/
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: Linux route -6/-A inet6 add command failed");
+
+#elif defined (WIN32)
+
+  /* netsh interface ipv6 add route 2001:db8::/32 MyTunDevice */
+  argv_printf (&argv, "%s%sc interface ipv6 add route %s/%d %s",
+	       get_win_sys_path(),
+	       NETSH_PATH_SUFFIX,
+	       network,
+	       r6->netbits,
+	       device);
+
+  /* next-hop depends on TUN or TAP mode:
+   * - in TAP mode, we use the "real" next-hop
+   * - in TUN mode we use a special-case link-local address that the tapdrvr
+   *   knows about and will answer ND (neighbor discovery) packets for
+   */
+  if ( tt->type == DEV_TYPE_TUN )
+	argv_printf_cat( &argv, " %s", "fe80::8" );
+  else
+	argv_printf_cat( &argv, " %s", gateway );
+
+#if 0
+  if (r->metric_defined)
+    argv_printf_cat (&argv, " METRIC %d", r->metric);
+#endif
+
+  /* in some versions of Windows, routes are persistent across reboots by
+   * default, unless "store=active" is set (pointed out by Tony Lim, thanks)
+   */
+  argv_printf_cat( &argv, " store=active" );
+
+  argv_msg (D_ROUTE, &argv);
+
+  netcmd_semaphore_lock ();
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: Windows route add ipv6 command failed");
+  netcmd_semaphore_release ();
+
+#elif defined (TARGET_SOLARIS)
+
+  /* example: route add -inet6 2001:db8::/32 somegateway 0 */
+
+  /* for some weird reason, this does not work for me unless I set
+   * "metric 0" - otherwise, the routes will be nicely installed, but
+   * packets will just disappear somewhere.  So we use "0" now...
+   */
+
+  argv_printf (&argv, "%s add -inet6 %s/%d %s 0",
+		ROUTE_PATH,
+		network,
+		r6->netbits,
+		gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: Solaris route add -inet6 command failed");
+
+#elif defined(TARGET_FREEBSD) || defined(TARGET_DRAGONFLY)
+
+  argv_printf (&argv, "%s add -inet6 %s/%d -iface %s",
+		ROUTE_PATH,
+	        network,
+	        r6->netbits,
+	        device );
+
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: *BSD route add -inet6 command failed");
+
+#elif defined(TARGET_DARWIN) 
+
+  argv_printf (&argv, "%s add -inet6 %s -prefixlen %d -iface %s",
+		ROUTE_PATH,
+	        network, r6->netbits, device );
+
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: MacOS X route add -inet6 command failed");
+
+#elif defined(TARGET_OPENBSD)
+
+  argv_printf (&argv, "%s add -inet6 %s -prefixlen %d %s",
+		ROUTE_PATH,
+	        network, r6->netbits, gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: OpenBSD route add -inet6 command failed");
+
+#elif defined(TARGET_NETBSD)
+
+  argv_printf (&argv, "%s add -inet6 %s/%d %s",
+		ROUTE_PATH,
+	        network, r6->netbits, gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  status = openvpn_execve_check (&argv, es, 0, "ERROR: NetBSD route add -inet6 command failed");
+
+#else
+  msg (M_FATAL, "Sorry, but I don't know how to do 'route ipv6' commands on this operating system.  Try putting your routes in a --route-up script");
+#endif
+
+  r6->defined = status;
+  argv_reset (&argv);
+  gc_free (&gc);
+}
+
 static void
 delete_route (const struct route *r, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
 {
@@ -1164,6 +1583,142 @@ delete_route (const struct route *r, const struct tuntap *tt, unsigned int flags
   gc_free (&gc);
 }
 
+void
+delete_route_ipv6 (const struct route_ipv6 *r6, const struct tuntap *tt, unsigned int flags, const struct env_set *es)
+{
+  struct gc_arena gc;
+  struct argv argv;
+  const char *network;
+  const char *gateway;
+  const char *device = tt->actual_name;
+
+  if (!r6->defined)
+    return;
+
+  gc_init (&gc);
+  argv_init (&argv);
+
+  network = print_in6_addr_netbits_only( r6->network, r6->netbits, &gc);
+  gateway = print_in6_addr( r6->gateway, 0, &gc);
+
+  if ( !tt->ipv6 )
+    {
+      msg( M_INFO, "delete_route_ipv6(): not deleting %s/%d, no IPv6 on if %s",
+		    network, r6->netbits, device );
+      return;
+    }
+
+  msg( M_INFO, "delete_route_ipv6(%s/%d)", network, r6->netbits );
+
+#if defined(TARGET_LINUX)
+#ifdef CONFIG_FEATURE_IPROUTE
+  argv_printf (&argv, "%s -6 route del %s/%d dev %s",
+  	      iproute_path,
+	      network,
+	      r6->netbits,
+	      device);
+#else
+  argv_printf (&argv, "%s -A inet6 del %s/%d dev %s",
+		ROUTE_PATH,
+	      network,
+	      r6->netbits,
+	      device);
+#endif  /*CONFIG_FEATURE_IPROUTE*/
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: Linux route -6/-A inet6 del command failed");
+
+#elif defined (WIN32)
+
+  /* netsh interface ipv6 delete route 2001:db8::/32 MyTunDevice */
+  argv_printf (&argv, "%s%sc interface ipv6 delete route %s/%d %s",
+	       get_win_sys_path(),
+	       NETSH_PATH_SUFFIX,
+	       network,
+	       r6->netbits,
+	       device);
+
+  /* next-hop depends on TUN or TAP mode:
+   * - in TAP mode, we use the "real" next-hop
+   * - in TUN mode we use a special-case link-local address that the tapdrvr
+   *   knows about and will answer ND (neighbor discovery) packets for
+   * (and "route deletion without specifying next-hop" does not work...)
+   */
+  if ( tt->type == DEV_TYPE_TUN )
+	argv_printf_cat( &argv, " %s", "fe80::8" );
+  else
+	argv_printf_cat( &argv, " %s", gateway );
+
+#if 0
+  if (r->metric_defined)
+    argv_printf_cat (&argv, "METRIC %d", r->metric);
+#endif
+
+  argv_msg (D_ROUTE, &argv);
+
+  netcmd_semaphore_lock ();
+  openvpn_execve_check (&argv, es, 0, "ERROR: Windows route add ipv6 command failed");
+  netcmd_semaphore_release ();
+
+#elif defined (TARGET_SOLARIS)
+
+  /* example: route delete -inet6 2001:db8::/32 somegateway */
+  /* GERT-TODO: this is untested, but should work */
+
+  argv_printf (&argv, "%s delete -inet6 %s/%d %s",
+		ROUTE_PATH,
+		network,
+		r6->netbits,
+		gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: Solaris route delete -inet6 command failed");
+
+#elif defined(TARGET_FREEBSD) || defined(TARGET_DRAGONFLY)
+
+  argv_printf (&argv, "%s delete -inet6 %s/%d -iface %s",
+		ROUTE_PATH,
+	        network,
+	        r6->netbits,
+	        device );
+
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: *BSD route delete -inet6 command failed");
+
+#elif defined(TARGET_DARWIN) 
+
+  argv_printf (&argv, "%s delete -inet6 %s -prefixlen %d -iface %s",
+		ROUTE_PATH, 
+		network, r6->netbits, device );
+
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: *BSD route delete -inet6 command failed");
+
+#elif defined(TARGET_OPENBSD)
+
+  argv_printf (&argv, "%s delete -inet6 %s -prefixlen %d %s",
+		ROUTE_PATH,
+	        network, r6->netbits, gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: OpenBSD route delete -inet6 command failed");
+
+#elif defined(TARGET_NETBSD)
+
+  argv_printf (&argv, "%s delete -inet6 %s/%d %s",
+		ROUTE_PATH,
+	        network, r6->netbits, gateway );
+
+  argv_msg (D_ROUTE, &argv);
+  openvpn_execve_check (&argv, es, 0, "ERROR: NetBSD route delete -inet6 command failed");
+
+#else
+  msg (M_FATAL, "Sorry, but I don't know how to do 'route ipv6' commands on this operating system.  Try putting your routes in a --route-down script");
+#endif
+
+  argv_reset (&argv);
+  gc_free (&gc);
+}
+
 /*
  * The --redirect-gateway option requires OS-specific code below
  * to get the current default gateway.
diff --git a/route.h b/route.h
index c5cbb7c..6a7704f 100644
--- a/route.h
+++ b/route.h
@@ -92,6 +92,19 @@ struct route_option_list {
   struct route_option routes[EMPTY_ARRAY_SIZE];
 };
 
+struct route_ipv6_option {
+  const char *prefix;		/* e.g. "2001:db8:1::/64" */
+  const char *gateway;		/* e.g. "2001:db8:0::2" */
+  const char *metric;		/* e.g. "5" */
+};
+
+struct route_ipv6_option_list {
+  unsigned int flags;
+  int capacity;
+  int n;
+  struct route_ipv6_option routes_ipv6[EMPTY_ARRAY_SIZE];
+};
+
 struct route {
   bool defined;
   const struct route_option *option;
@@ -113,6 +126,31 @@ struct route_list {
   struct route routes[EMPTY_ARRAY_SIZE];
 };
 
+struct route_ipv6 {
+  bool defined;
+  const struct route_ipv6_option *option;
+  struct in6_addr network;
+  unsigned int netbits;
+  struct in6_addr gateway;
+  bool metric_defined;
+  int metric;
+};
+
+struct route_ipv6_list {
+  bool routes_added;
+  unsigned int flags;
+  int default_metric;
+  bool default_metric_defined;
+  struct in6_addr remote_endpoint_ipv6;
+  bool remote_endpoint_defined;
+  bool did_redirect_default_gateway;			/* TODO (?) */
+  bool did_local;					/* TODO (?) */
+  int capacity;
+  int n;
+  struct route_ipv6 routes_ipv6[EMPTY_ARRAY_SIZE];
+};
+
+
 #if P2MP
 /* internal OpenVPN route */
 struct iroute {
@@ -120,15 +158,25 @@ struct iroute {
   int netbits;
   struct iroute *next;
 };
+
+struct iroute_ipv6 {
+  struct in6_addr network;
+  unsigned int netbits;
+  struct iroute_ipv6 *next;
+};
 #endif
 
 struct route_option_list *new_route_option_list (const int max_routes, struct gc_arena *a);
+struct route_ipv6_option_list *new_route_ipv6_option_list (const int max_routes, struct gc_arena *a);
 struct route_option_list *clone_route_option_list (const struct route_option_list *src, struct gc_arena *a);
 void copy_route_option_list (struct route_option_list *dest, const struct route_option_list *src);
 
 struct route_list *new_route_list (const int max_routes, struct gc_arena *a);
+struct route_ipv6_list *new_route_ipv6_list (const int max_routes, struct gc_arena *a);
 
 void add_route (struct route *r, const struct tuntap *tt, unsigned int flags, const struct env_set *es);
+void add_route_ipv6 (struct route_ipv6 *r, const struct tuntap *tt, unsigned int flags, const struct env_set *es);
+void delete_route_ipv6 (const struct route_ipv6 *r, const struct tuntap *tt, unsigned int flags, const struct env_set *es);
 
 void add_route_to_option_list (struct route_option_list *l,
 			       const char *network,
@@ -136,6 +184,11 @@ void add_route_to_option_list (struct route_option_list *l,
 			       const char *gateway,
 			       const char *metric);
 
+void add_route_ipv6_to_option_list (struct route_ipv6_option_list *l,
+			       const char *prefix,
+			       const char *gateway,
+			       const char *metric);
+
 bool init_route_list (struct route_list *rl,
 		      const struct route_option_list *opt,
 		      const char *remote_endpoint,
@@ -143,21 +196,30 @@ bool init_route_list (struct route_list *rl,
 		      in_addr_t remote_host,
 		      struct env_set *es);
 
+bool init_route_ipv6_list (struct route_ipv6_list *rl6,
+		      const struct route_ipv6_option_list *opt6,
+		      const char *remote_endpoint,
+		      int default_metric,
+		      struct env_set *es);
+
 void route_list_add_default_gateway (struct route_list *rl,
 				     struct env_set *es,
 				     const in_addr_t addr);
 
 void add_routes (struct route_list *rl,
+		 struct route_ipv6_list *rl6,
 		 const struct tuntap *tt,
 		 unsigned int flags,
 		 const struct env_set *es);
 
 void delete_routes (struct route_list *rl,
+		    struct route_ipv6_list *rl6,
 		    const struct tuntap *tt,
 		    unsigned int flags,
 		    const struct env_set *es);
 
 void setenv_routes (struct env_set *es, const struct route_list *rl);
+void setenv_routes_ipv6 (struct env_set *es, const struct route_ipv6_list *rl6);
 
 bool is_special_addr (const char *addr_str);
 
diff --git a/socket.c b/socket.c
index 4720398..c04edc9 100644
--- a/socket.c
+++ b/socket.c
@@ -342,6 +342,24 @@ ip_addr_dotted_quad_safe (const char *dotted_quad)
   }
 }
 
+bool
+ipv6_addr_safe (const char *ipv6_text_addr)
+{
+  /* verify non-NULL */
+  if (!ipv6_text_addr)
+    return false;
+
+  /* verify length is within limits */
+  if (strlen (ipv6_text_addr) > INET6_ADDRSTRLEN )
+    return false;
+
+  /* verify that string will convert to IPv6 address */
+  {
+    struct in6_addr a6;
+    return inet_pton( AF_INET6, ipv6_text_addr, &a6 ) == 1;
+  }
+}
+
 static bool
 dns_addr_safe (const char *addr)
 {
@@ -2032,6 +2050,55 @@ print_in_addr_t (in_addr_t addr, unsigned int flags, struct gc_arena *gc)
   return BSTR (&out);
 }
 
+/*
+ * Convert an in6_addr in host byte order
+ * to an ascii representation of an IPv6 address
+ */
+const char *
+print_in6_addr (struct in6_addr a6, unsigned int flags, struct gc_arena *gc)
+{
+  struct buffer out = alloc_buf_gc (64, gc);
+  char tmp_out_buf[64];		/* inet_ntop wants pointer to buffer */
+
+  if ( memcmp(&a6, &in6addr_any, sizeof(a6)) != 0 || 
+       !(flags & IA_EMPTY_IF_UNDEF))
+    {
+      inet_ntop (AF_INET6, &a6, tmp_out_buf, sizeof(tmp_out_buf)-1);
+      buf_printf (&out, "%s", tmp_out_buf );
+    }
+  return BSTR (&out);
+}
+
+/* add some offset to an ipv6 address
+ * (add in steps of 32 bits, taking overflow into next round)
+ */
+#ifndef s6_addr32
+# ifdef TARGET_SOLARIS
+#  define s6_addr32 _S6_un._S6_u32
+# else
+#  define s6_addr32 __u6_addr.__u6_addr32
+# endif
+#endif
+#ifndef UINT32_MAX
+# define UINT32_MAX (4294967295U)
+#endif
+struct in6_addr add_in6_addr( struct in6_addr base, uint32_t add )
+{
+    int i;
+    uint32_t h;
+
+    for( i=3; i>=0 && add > 0 ; i-- )
+    {
+	h = ntohl( base.s6_addr32[i] );
+	base.s6_addr32[i] = htonl( (h+add) & UINT32_MAX );
+	/* 32-bit overrun? 
+	 * caveat: can't do "h+add > UINT32_MAX" with 32bit math!
+         */
+	add = ( h > UINT32_MAX - add )?  1: 0;
+    }
+    return base;
+}
+
 /* set environmental variables for ip/port in *addr */
 void
 setenv_sockaddr (struct env_set *es, const char *name_prefix, const struct openvpn_sockaddr *addr, const bool flags)
@@ -2337,6 +2404,58 @@ link_socket_write_udp_posix_sendmsg (struct link_socket *sock,
 
 #ifdef WIN32
 
+/*
+ * inet_ntop() and inet_pton() wrap-implementations using
+ * WSAAddressToString() and WSAStringToAddress() functions
+ */
+const char *
+inet_ntop(int af, const void *src, char *dst, socklen_t size)
+{
+  struct sockaddr_storage ss;
+  unsigned long s = size;
+
+  CLEAR(ss);
+  ss.ss_family = af;
+
+  switch(af) {
+    case AF_INET:
+      ((struct sockaddr_in *)&ss)->sin_addr = *(struct in_addr *)src;
+      break;
+    case AF_INET6:
+      ((struct sockaddr_in6 *)&ss)->sin6_addr = *(struct in6_addr *)src;
+      break;
+    default:
+      ASSERT (0);
+  }
+  // cannot direclty use &size because of strict aliasing rules
+  return (WSAAddressToString((struct sockaddr *)&ss, sizeof(ss), NULL, dst, &s) == 0)?
+          dst : NULL;
+}
+
+int
+inet_pton(int af, const char *src, void *dst)
+{
+  struct sockaddr_storage ss;
+  int size = sizeof(ss);
+  char src_copy[INET6_ADDRSTRLEN+1];
+
+  CLEAR(ss);
+  // stupid non-const API
+  strncpynt(src_copy, src, INET6_ADDRSTRLEN+1);
+
+  if (WSAStringToAddress(src_copy, af, NULL, (struct sockaddr *)&ss, &size) == 0) {
+    switch(af) {
+      case AF_INET:
+	*(struct in_addr *)dst = ((struct sockaddr_in *)&ss)->sin_addr;
+	return 1;
+      case AF_INET6:
+	*(struct in6_addr *)dst = ((struct sockaddr_in6 *)&ss)->sin6_addr;
+	return 1;
+    }
+  }
+  return 0;
+}
+
 int
 socket_recv_queue (struct link_socket *sock, int maxsize)
 {
diff --git a/socket.h b/socket.h
index eef98d1..17943e7 100644
--- a/socket.h
+++ b/socket.h
@@ -351,6 +351,8 @@ const char *print_link_socket_actual (const struct link_socket_actual *act,
 #define IA_EMPTY_IF_UNDEF (1<<0)
 #define IA_NET_ORDER      (1<<1)
 const char *print_in_addr_t (in_addr_t addr, unsigned int flags, struct gc_arena *gc);
+const char *print_in6_addr  (struct in6_addr addr6, unsigned int flags, struct gc_arena *gc);
+struct in6_addr add_in6_addr( struct in6_addr base, uint32_t add );
 
 #define SA_IP_PORT        (1<<0)
 #define SA_SET_IF_NONZERO (1<<1)
@@ -404,6 +406,7 @@ int openvpn_inet_aton (const char *dotted_quad, struct in_addr *addr);
 bool ip_addr_dotted_quad_safe (const char *dotted_quad);
 bool ip_or_dns_addr_safe (const char *addr, const bool allow_fqdn);
 bool mac_addr_safe (const char *mac_addr);
+bool ipv6_addr_safe (const char *ipv6_text_addr);
 
 socket_descriptor_t create_socket_tcp (void);
 
diff --git a/syshead.h b/syshead.h
index b81ce59..fe4af3f 100644
--- a/syshead.h
+++ b/syshead.h
@@ -28,6 +28,10 @@
 /*
  * Only include if not during configure
  */
+#ifdef WIN32
+/* USE_PF_INET6: win32 ipv6 exists only after 0x0501 (XP) */
+#define WINVER 0x0501
+#endif
 #ifndef PACKAGE_NAME
 #include "config.h"
 #endif
@@ -339,6 +343,9 @@
 #ifdef WIN32
 #include <iphlpapi.h>
 #include <wininet.h>
+/* The following two headers are needed of USE_PF_INET6 */
+#include <winsock2.h>
+#include <ws2tcpip.h>
 #endif
 
 #ifdef HAVE_SYS_MMAN_H
diff --git a/tun.c b/tun.c
index d03e8c7..4be71de 100644
--- a/tun.c
+++ b/tun.c
@@ -56,13 +56,14 @@ static void netsh_ifconfig (const struct tuntap_options *to,
 			    const in_addr_t ip,
 			    const in_addr_t netmask,
 			    const unsigned int flags);
+static void netsh_command (const struct argv *a, int n);
 
 static const char *netsh_get_id (const char *dev_node, struct gc_arena *gc);
 
 #endif
 
 #ifdef TARGET_SOLARIS
-static void solaris_error_close (struct tuntap *tt, const struct env_set *es, const char *actual);
+static void solaris_error_close (struct tuntap *tt, const struct env_set *es, const char *actual, bool unplumb_inet6);
 #include <stropts.h>
 #endif
 
@@ -129,30 +130,6 @@ guess_tuntap_dev (const char *dev,
   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)";
@@ -423,6 +400,8 @@ init_tun (const char *dev,       /* --dev option */
 	  int topology,          /* one of the TOP_x values */
 	  const char *ifconfig_local_parm,          /* --ifconfig parm 1 */
 	  const char *ifconfig_remote_netmask_parm, /* --ifconfig parm 2 */
+	  const char *ifconfig_ipv6_local_parm,     /* --ifconfig parm 1 IPv6 */
+	  const char *ifconfig_ipv6_remote_parm,    /* --ifconfig parm 2 IPv6 */
 	  in_addr_t local_public,
 	  in_addr_t remote_public,
 	  const bool strict_warn,
@@ -537,6 +516,40 @@ init_tun (const char *dev,       /* --dev option */
 
       tt->did_ifconfig_setup = true;
     }
+
+  if (ifconfig_ipv6_local_parm && ifconfig_ipv6_remote_parm)
+    {
+      const char *ifconfig_ipv6_local = NULL;
+      const char *ifconfig_ipv6_remote = NULL;
+
+      /*
+       * Convert arguments to binary IPv6 addresses.
+       */
+
+      if ( inet_pton( AF_INET6, ifconfig_ipv6_local_parm, &tt->local_ipv6 ) != 1 ||
+           inet_pton( AF_INET6, ifconfig_ipv6_remote_parm, &tt->remote_ipv6 ) != 1 ) 
+	{
+	  msg( M_FATAL, "init_tun: problem converting IPv6 ifconfig addresses %s and %s to binary", ifconfig_ipv6_local_parm, ifconfig_ipv6_remote_parm );
+	}
+      tt->netbits_ipv6 = 64;
+
+      /*
+       * Set ifconfig parameters
+       */
+      ifconfig_ipv6_local = print_in6_addr (tt->local_ipv6, 0, &gc);
+      ifconfig_ipv6_remote = print_in6_addr (tt->remote_ipv6, 0, &gc);
+
+      /*
+       * Set environmental variables with ifconfig parameters.
+       */
+      if (es)
+	{
+	  setenv_str (es, "ifconfig_ipv6_local", ifconfig_ipv6_local);
+	  setenv_str (es, "ifconfig_ipv6_remote", ifconfig_ipv6_remote);
+	}
+      tt->did_ifconfig_ipv6_setup = true;
+    }
+
   gc_free (&gc);
   return tt;
 }
@@ -559,6 +572,40 @@ init_tun_post (struct tuntap *tt,
 #endif
 }
 
+#if defined(TARGET_WIN32) || \
+    defined(TARGET_DARWIN) || defined(TARGET_NETBSD) || defined(TARGET_OPENBSD)
+
+/* some of the platforms will auto-add a "network route" pointing
+ * to the interface on "ifconfig tunX 2001:db8::1/64", others need
+ * an extra call to "route add..."
+ * -> helper function to simplify code below
+ */
+void add_route_connected_v6_net(struct tuntap * tt,
+	                        const struct env_set *es)
+{
+    struct route_ipv6 r6;
+
+    r6.defined = true;
+    r6.network = tt->local_ipv6;
+    r6.netbits = tt->netbits_ipv6;
+    r6.gateway = tt->local_ipv6;
+    add_route_ipv6 (&r6, tt, 0, es);
+}
+
+void delete_route_connected_v6_net(struct tuntap * tt,
+	                           const struct env_set *es)
+{
+    struct route_ipv6 r6;
+
+    r6.defined = true;
+    r6.network = tt->local_ipv6;
+    r6.netbits = tt->netbits_ipv6;
+    r6.gateway = tt->local_ipv6;
+    delete_route_ipv6 (&r6, tt, 0, es);
+}
+#endif
+
+
 /* execute the ifconfig command through the shell */
 void
 do_ifconfig (struct tuntap *tt,
@@ -574,10 +621,16 @@ do_ifconfig (struct tuntap *tt,
       const char *ifconfig_local = NULL;
       const char *ifconfig_remote_netmask = NULL;
       const char *ifconfig_broadcast = NULL;
+      const char *ifconfig_ipv6_local = NULL;
+      const char *ifconfig_ipv6_remote = NULL;
+      bool do_ipv6 = false;
       struct argv argv;
 
       argv_init (&argv);
 
+      msg( M_INFO, "do_ifconfig, tt->ipv6=%d, tt->did_ifconfig_ipv6_setup=%d",
+	           tt->ipv6, tt->did_ifconfig_ipv6_setup );
+
       /*
        * We only handle TUN/TAP devices here, not --dev null devices.
        */
@@ -589,6 +642,13 @@ do_ifconfig (struct tuntap *tt,
       ifconfig_local = print_in_addr_t (tt->local, 0, &gc);
       ifconfig_remote_netmask = print_in_addr_t (tt->remote_netmask, 0, &gc);
 
+      if ( tt->ipv6 && tt->did_ifconfig_ipv6_setup )
+        {
+	  ifconfig_ipv6_local = print_in6_addr (tt->local_ipv6, 0, &gc);
+	  ifconfig_ipv6_remote = print_in6_addr (tt->remote_ipv6, 0, &gc);
+	  do_ipv6 = true;
+	}
+
       /*
        * If TAP-style device, generate broadcast address.
        */
@@ -647,7 +707,19 @@ do_ifconfig (struct tuntap *tt,
 		  argv_msg (M_INFO, &argv);
 		  openvpn_execve_check (&argv, es, S_FATAL, "Linux ip addr add failed");
 	}
-	tt->did_ifconfig = true;
+      if ( do_ipv6 )
+	{
+	  argv_printf( &argv,
+		      "%s -6 addr add %s/%d dev %s",
+		      iproute_path,
+		      ifconfig_ipv6_local,
+		      tt->netbits_ipv6,
+		      actual
+		      );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "Linux ip -6 addr add failed");
+	}
+      tt->did_ifconfig = true;
 #else
       if (tun)
 	argv_printf (&argv,
@@ -670,6 +742,18 @@ do_ifconfig (struct tuntap *tt,
 			  );
       argv_msg (M_INFO, &argv);
       openvpn_execve_check (&argv, es, S_FATAL, "Linux ifconfig failed");
+      if ( do_ipv6 )
+	{
+	  argv_printf (&argv,
+			  "%s %s inet6 add %s/%d",
+			  IFCONFIG_PATH,
+			  actual,
+			  ifconfig_ipv6_local,
+			  tt->netbits_ipv6
+			  );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "Linux ifconfig inet6 failed");
+	}
       tt->did_ifconfig = true;
 
 #endif /*CONFIG_FEATURE_IPROUTE*/
@@ -693,7 +777,7 @@ do_ifconfig (struct tuntap *tt,
 
 	  argv_msg (M_INFO, &argv);
 	  if (!openvpn_execve_check (&argv, es, 0, "Solaris ifconfig phase-1 failed"))
-	    solaris_error_close (tt, es, actual);
+	    solaris_error_close (tt, es, actual, false);
 
 	  argv_printf (&argv,
 			    "%s %s netmask 255.255.255.255",
@@ -725,7 +809,53 @@ do_ifconfig (struct tuntap *tt,
 
       argv_msg (M_INFO, &argv);
       if (!openvpn_execve_check (&argv, es, 0, "Solaris ifconfig phase-2 failed"))
-	solaris_error_close (tt, es, actual);
+	solaris_error_close (tt, es, actual, false);
+
+      if ( do_ipv6 )
+        {
+ 	  argv_printf (&argv, "%s %s inet6 unplumb",
+			    IFCONFIG_PATH, actual );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, 0, NULL);
+
+	  if ( tt->type == DEV_TYPE_TUN )
+	   {
+	      argv_printf (&argv,
+			    "%s %s inet6 plumb %s/%d %s up",
+			    IFCONFIG_PATH,
+			    actual,
+			    ifconfig_ipv6_local,
+			    tt->netbits_ipv6,
+			    ifconfig_ipv6_remote
+			    );
+	    }
+	  else						/* tap mode */
+	    {
+	      /* base IPv6 tap interface needs to be brought up first
+	       */
+	      argv_printf (&argv, "%s %s inet6 plumb up",
+			    IFCONFIG_PATH, actual );
+	      argv_msg (M_INFO, &argv);
+	      if (!openvpn_execve_check (&argv, es, 0, "Solaris ifconfig IPv6 (prepare) failed"))
+		solaris_error_close (tt, es, actual, true);
+
+	      /* we might need to do "ifconfig %s inet6 auto-dhcp drop"
+	       * after the system has noticed the interface and fired up
+	       * the DHCPv6 client - but this takes quite a while, and the 
+	       * server will ignore the DHCPv6 packets anyway.  So we don't.
+	       */
+
+	      /* static IPv6 addresses need to go to a subinterface (tap0:1)
+	       */
+	      argv_printf (&argv,
+			    "%s %s inet6 addif %s/%d up",
+			    IFCONFIG_PATH, actual,
+			    ifconfig_ipv6_local, tt->netbits_ipv6 );
+	    }
+	  argv_msg (M_INFO, &argv);
+	  if (!openvpn_execve_check (&argv, es, 0, "Solaris ifconfig IPv6 failed"))
+	    solaris_error_close (tt, es, actual, true);
+        }
 
       if (!tun && tt->topology == TOP_SUBNET)
 	{
@@ -787,10 +917,42 @@ do_ifconfig (struct tuntap *tt,
 			  );
       argv_msg (M_INFO, &argv);
       openvpn_execve_check (&argv, es, S_FATAL, "OpenBSD ifconfig failed");
+      if ( do_ipv6 )
+	{
+	  argv_printf (&argv,
+			  "%s %s inet6 %s/%d",
+			  IFCONFIG_PATH,
+			  actual,
+			  ifconfig_ipv6_local,
+			  tt->netbits_ipv6
+			  );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "OpenBSD ifconfig inet6 failed");
+
+	  /* and, hooray, we explicitely need to add a route... */
+	  add_route_connected_v6_net(tt, es);
+	}
       tt->did_ifconfig = true;
 
 #elif defined(TARGET_NETBSD)
 
+/* whether or not NetBSD can do IPv6 can be seen by the availability of
+ * the TUNSIFHEAD ioctl() - see next TARGET_NETBSD block for more details
+ */
+#ifdef TUNSIFHEAD
+# define NETBSD_MULTI_AF
+#endif
+
+      /* as on OpenBSD and Darwin, destroy and re-create tun<x> interface
+       */
+      argv_printf (&argv, "%s %s destroy", IFCONFIG_PATH, actual );
+      argv_msg (M_INFO, &argv);
+      openvpn_execve_check (&argv, es, 0, "NetBSD ifconfig destroy failed");
+
+      argv_printf (&argv, "%s %s create", IFCONFIG_PATH, actual );
+      argv_msg (M_INFO, &argv);
+      openvpn_execve_check (&argv, es, S_FATAL, "NetBSD ifconfig create failed");
+
       if (tun)
 	argv_printf (&argv,
 			  "%s %s %s %s mtu %d netmask 255.255.255.255 up",
@@ -817,6 +979,27 @@ do_ifconfig (struct tuntap *tt,
 			  );
       argv_msg (M_INFO, &argv);
       openvpn_execve_check (&argv, es, S_FATAL, "NetBSD ifconfig failed");
+
+      if ( do_ipv6 )
+	{
+#ifdef NETBSD_MULTI_AF
+	  argv_printf (&argv,
+			  "%s %s inet6 %s/%d",
+			  IFCONFIG_PATH,
+			  actual,
+			  ifconfig_ipv6_local,
+			  tt->netbits_ipv6
+			  );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "NetBSD ifconfig inet6 failed");
+
+	  /* and, hooray, we explicitely need to add a route... */
+	  add_route_connected_v6_net(tt, es);
+#else
+	  msg( M_INFO, "no IPv6 support for tun interfaces on NetBSD before 4.0 (if your system is newer, recompile openvpn)" );
+	  tt->ipv6 = false;
+#endif
+	}
       tt->did_ifconfig = true;
 
 #elif defined(TARGET_DARWIN)
@@ -882,6 +1065,22 @@ do_ifconfig (struct tuntap *tt,
 	  add_route (&r, tt, 0, es);
 	}
 
+      if ( do_ipv6 )
+	{
+          argv_printf (&argv,
+                              "%s %s inet6 %s/%d",
+                              IFCONFIG_PATH,
+                              actual,
+                              ifconfig_ipv6_local,
+                              tt->netbits_ipv6
+                              );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "MacOS X ifconfig inet6 failed");
+
+	  /* and, hooray, we explicitely need to add a route... */
+	  add_route_connected_v6_net(tt, es);
+	}
+
 #elif defined(TARGET_FREEBSD)||defined(TARGET_DRAGONFLY)
 
       /* example: ifconfig tun2 10.2.0.2 10.2.0.1 mtu 1450 netmask 255.255.255.255 up */
@@ -920,6 +1119,19 @@ do_ifconfig (struct tuntap *tt,
           add_route (&r, tt, 0, es);
         }
 
+      if ( do_ipv6 )
+	{
+          argv_printf (&argv,
+                              "%s %s inet6 %s/%d",
+                              IFCONFIG_PATH,
+                              actual,
+                              ifconfig_ipv6_local,
+                              tt->netbits_ipv6
+                              );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, es, S_FATAL, "FreeBSD ifconfig inet6 failed");
+	}
+
 #elif defined (WIN32)
       {
 	/*
@@ -959,6 +1171,34 @@ do_ifconfig (struct tuntap *tt,
 	tt->did_ifconfig = true;
       }
 
+    /* IPv6 always uses "netsh" interface */
+    if ( do_ipv6 )
+      {
+	char * saved_actual;
+
+	if (!strcmp (actual, "NULL"))
+	  msg (M_FATAL, "Error: When using --tun-ipv6, if you have more than one TAP-Win32 adapter, you must also specify --dev-node");
+
+	/* example: netsh interface ipv6 set address MyTap 2001:608:8003::d store=active */
+	argv_printf (&argv,
+		    "%s%sc interface ipv6 set address %s %s store=active",
+		     get_win_sys_path(),
+		     NETSH_PATH_SUFFIX,
+		     actual,
+		     ifconfig_ipv6_local );
+
+	netsh_command (&argv, 4);
+
+	/* explicit route needed */
+	/* on windows, OpenVPN does ifconfig first, open_tun later, so
+	 * tt->actual_name might not yet be initialized, but routing code
+	 * needs to know interface name - point to "actual", restore later
+	 */
+	saved_actual = tt->actual_name;
+	tt->actual_name = (char*) actual;
+	add_route_connected_v6_net(tt, es);
+	tt->actual_name = saved_actual;
+      }
 #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
@@ -991,14 +1231,16 @@ open_null (struct tuntap *tt)
 #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,
+		  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->ipv6 && ! ipv6_explicitly_supported )
+    msg (M_WARN, "NOTE: explicit support for IPv6 tun devices is not provided for this OS");
 
   if (tt->type == DEV_TYPE_NULL)
     {
@@ -1094,16 +1336,16 @@ close_tun_generic (struct tuntap *tt)
 #if !PEDANTIC
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, 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.
+  /* warn if a very old linux version is used & --tun-ipv6 set
    */
-  ipv6_support (ipv6, LINUX_IPV6, tt);
+#if LINUX_IPV6 == 0
+  if ( tt->ipv6 )
+    msg (M_WARN, "NOTE: explicit support for IPv6 tun devices is not provided for this OS");
+#endif
 
   /*
    * We handle --dev null specially, we do not open /dev/null for this.
@@ -1222,9 +1464,9 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6
 #else
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-  open_tun_generic (dev, dev_type, dev_node, ipv6, false, true, tt);
+  open_tun_generic (dev, dev_type, dev_node, false, true, tt);
 }
 
 #endif /* HAVE_LINUX_IF_TUN_H */
@@ -1244,7 +1486,7 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6
 #endif
 
 void
-tuncfg (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, int persist_mode, const char *username, const char *groupname, const struct tuntap_options *options)
+tuncfg (const char *dev, const char *dev_type, const char *dev_node, int persist_mode, const char *username, const char *groupname, const struct tuntap_options *options)
 {
   struct tuntap *tt;
 
@@ -1252,7 +1494,7 @@ tuncfg (const char *dev, const char *dev_type, const char *dev_node, bool ipv6,
   clear_tuntap (tt);
   tt->type = dev_type_enum (dev, dev_type);
   tt->options = *options;
-  open_tun (dev, dev_type, dev_node, ipv6, tt);
+  open_tun (dev, dev_type, dev_node, tt);
   if (ioctl (tt->fd, TUNSETPERSIST, persist_mode) < 0)
     msg (M_ERR, "Cannot ioctl TUNSETPERSIST(%d) %s", persist_mode, dev);
   if (username != NULL)
@@ -1395,7 +1637,7 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
 #endif
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
   int if_fd, ip_muxid, arp_muxid, arp_fd, ppa = -1;
   struct lifreq ifr;
@@ -1406,8 +1648,11 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6
   bool is_tun;
   struct strioctl  strioc_if, strioc_ppa;
 
-  ipv6_support (ipv6, true, tt);
-  memset(&ifr, 0x0, sizeof(ifr));
+  /* improved generic TUN/TAP driver from
+   * http://www.whiteboard.ne.jp/~admin2/tuntap/
+   * has IPv6 support
+   */
+  CLEAR(ifr);
 
   if (tt->type == DEV_TYPE_NULL)
     {
@@ -1561,6 +1806,18 @@ solaris_close_tun (struct tuntap *tt)
 {
   if (tt)
     {
+      /* IPv6 interfaces need to be 'manually' de-configured */
+      if ( tt->ipv6 && tt->did_ifconfig_ipv6_setup )
+	{
+	  struct argv argv;
+	  argv_init (&argv);
+	  argv_printf( &argv, "%s %s inet6 unplumb",
+		       IFCONFIG_PATH, tt->actual_name );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, NULL, 0, "Solaris ifconfig inet6 unplumb failed");
+	  argv_reset (&argv);
+	}
+
       if (tt->ip_fd >= 0)
 	{
           struct lifreq ifr;
@@ -1613,11 +1870,20 @@ close_tun (struct tuntap *tt)
 }
 
 static void
-solaris_error_close (struct tuntap *tt, const struct env_set *es, const char *actual)
+solaris_error_close (struct tuntap *tt, const struct env_set *es, 
+                     const char *actual, bool unplumb_inet6 )
 {
   struct argv argv;
   argv_init (&argv);
 
+  if (unplumb_inet6)
+    {
+      argv_printf( &argv, "%s %s inet6 unplumb",
+		   IFCONFIG_PATH, actual );
+      argv_msg (M_INFO, &argv);
+      openvpn_execve_check (&argv, es, 0, "Solaris ifconfig inet6 unplumb failed");
+    }
+
   argv_printf (&argv,
 		    "%s %s unplumb",
 		    IFCONFIG_PATH,
@@ -1674,9 +1940,9 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
  */
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-  open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
+  open_tun_generic (dev, dev_type, dev_node, true, true, tt);
 
   /* Enable multicast on the interface */
   if (tt->fd >= 0)
@@ -1697,12 +1963,31 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6
     }
 }
 
+/* the current way OpenVPN handles tun devices on OpenBSD leads to
+ * lingering tunX interfaces after close -> for a full cleanup, they
+ * need to be explicitely destroyed
+ */
+
 void
 close_tun (struct tuntap* tt)
 {
   if (tt)
     {
+      struct gc_arena gc = gc_new ();
+      struct argv argv;
+
+      /* setup command, close tun dev (clears tt->actual_name!), run command
+       */
+
+      argv_init (&argv);
+      argv_printf (&argv, "%s %s destroy",
+                          IFCONFIG_PATH, tt->actual_name);
+
       close_tun_generic (tt);
+
+      argv_msg (M_INFO, &argv);
+      openvpn_execve_check (&argv, NULL, 0, "OpenBSD 'destroy tun interface' failed (non-critical)");
+
       free (tt);
     }
 }
@@ -1765,33 +2050,51 @@ read_tun (struct tuntap* tt, uint8_t *buf, int 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.
+ * NetBSD before 4.0 does not support IPv6 on tun out of the box,
+ * but there exists a patch (sys/net/if_tun.c, 1.79->1.80, see PR 32944).
+ *
+ * NetBSD 4.0 and up do, but we need to put the tun interface into
+ * "multi_af" mode, which will prepend the address family to all packets
+ * (same as OpenBSD and FreeBSD).  If this is not enabled, the kernel
+ * silently drops all IPv6 packets on output and gets confused on input.
+ *
+ * On earlier versions, multi_af is not available at all, so we have
+ * two different NetBSD code variants here :-(
+ *
  */
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-    open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
+#ifdef NETBSD_MULTI_AF
+    open_tun_generic (dev, dev_type, dev_node, true, true, tt);
+#else
+    open_tun_generic (dev, dev_type, dev_node, false, true, tt);
+#endif
+
     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 */
+
+#ifdef NETBSD_MULTI_AF
+        i = 1;
+        if (ioctl (tt->fd, TUNSIFHEAD, &i) < 0) 	/* multi-af mode on */
+	  {
+	    msg (M_WARN | M_ERRNO, "ioctl(TUNSIFHEAD): %s", strerror(errno));
+	  }
+#endif
       }
 }
 
 void
 close_tun (struct tuntap *tt)
 {
+  /* TODO: we really should cleanup non-persistant tunX with 
+   * "ifconfig tunX destroy" here...
+   */
   if (tt)
     {
       close_tun_generic (tt);
@@ -1799,6 +2102,65 @@ close_tun (struct tuntap *tt)
     }
 }
 
+#ifdef NETBSD_MULTI_AF
+
+static inline int
+netbsd_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 openvpn_iphdr *iph;
+
+      iph = (struct openvpn_iphdr *) buf;
+
+      if (tt->ipv6 && OPENVPN_IPH_GET_VER(iph->version_len) == 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 netbsd_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 netbsd_modify_read_write_return (readv (tt->fd, iv, 2));
+    }
+  else
+    return read (tt->fd, buf, len);
+}
+
+#else	/* not NETBSD_MULTI_AF -> older code, IPv4 only */
+
 int
 write_tun (struct tuntap* tt, uint8_t *buf, int len)
 {
@@ -1810,6 +2172,7 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
 {
     return read (tt->fd, buf, len);
 }
+#endif	/* NETBSD_MULTI_AF */
 
 #elif defined(TARGET_FREEBSD)
 
@@ -1823,9 +2186,9 @@ freebsd_modify_read_write_return (int len)
 }
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-  open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
+  open_tun_generic (dev, dev_type, dev_node, true, true, tt);
 
   if (tt->fd >= 0 && tt->type == DEV_TYPE_TUN)
     {
@@ -1911,9 +2274,9 @@ dragonfly_modify_read_write_return (int len)
 }
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-  open_tun_generic (dev, dev_type, dev_node, ipv6, true, true, tt);
+  open_tun_generic (dev, dev_type, dev_node, true, true, tt);
 
   if (tt->fd >= 0)
     {
@@ -1982,6 +2345,61 @@ read_tun (struct tuntap* tt, uint8_t *buf, int len)
     return read (tt->fd, buf, len);
 }
 
+#elif defined(TARGET_DARWIN)
+
+/* Darwin (MacOS X) is mostly "just use the generic stuff", but there
+ * is always one caveat...:
+ *
+ * If IPv6 is configured, and the tun device is closed, the IPv6 address
+ * configured to the tun interface changes to a lingering /128 route
+ * pointing to lo0.  Need to unconfigure...  (observed on 10.5)
+ */
+
+void
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
+{
+  open_tun_generic (dev, dev_type, dev_node, false, true, tt);
+}
+
+void
+close_tun (struct tuntap* tt)
+{
+  if (tt)
+    {
+      struct gc_arena gc = gc_new ();
+      struct argv argv;
+      argv_init (&argv);
+
+      if ( tt->ipv6 && tt->did_ifconfig_ipv6_setup )
+	{
+	  const char * ifconfig_ipv6_local =
+				print_in6_addr (tt->local_ipv6, 0, &gc);
+
+          argv_printf (&argv, "%s delete -inet6 %s",
+                              ROUTE_PATH, ifconfig_ipv6_local );
+	  argv_msg (M_INFO, &argv);
+	  openvpn_execve_check (&argv, NULL, 0, "MacOS X 'remove inet6 route' failed (non-critical)");
+	}
+
+      close_tun_generic (tt);
+      free (tt);
+      argv_reset (&argv);
+      gc_free (&gc);
+    }
+}
+
+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(WIN32)
 
 int
@@ -3967,7 +4385,7 @@ fork_register_dns_action (struct tuntap *tt)
 }
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
   struct gc_arena gc = gc_new ();
   char device_path[256];
@@ -3978,7 +4396,7 @@ open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6
 
   /*netcmd_semaphore_lock ();*/
 
-  ipv6_support (ipv6, false, tt);
+  msg( M_INFO, "open_tun, tt->ipv6=%d", tt->ipv6 );
 
   if (tt->type == DEV_TYPE_NULL)
     {
@@ -4432,6 +4850,26 @@ close_tun (struct tuntap *tt)
 
   if (tt)
     {
+      if ( tt->ipv6 && tt->did_ifconfig_ipv6_setup )
+        {
+	  struct argv argv;
+	  argv_init (&argv);
+
+	  /* remove route pointing to interface */
+	  delete_route_connected_v6_net(tt, NULL);
+
+	  /* netsh interface ipv6 delete address \"%s\" %s */
+	  const char * ifconfig_ipv6_local = print_in6_addr (tt->local_ipv6, 0, &gc);
+	  argv_printf (&argv,
+		    "%s%sc interface ipv6 delete address %s %s",
+		     get_win_sys_path(),
+		     NETSH_PATH_SUFFIX,
+		     tt->actual_name,
+		     ifconfig_ipv6_local );
+
+	  netsh_command (&argv, 1);
+          argv_reset (&argv);
+	}
 #if 1
       if (tt->ipapi_context_defined)
 	{
@@ -4535,9 +4973,9 @@ ipset2ascii_all (struct gc_arena *gc)
 #else /* generic */
 
 void
-open_tun (const char *dev, const char *dev_type, const char *dev_node, bool ipv6, struct tuntap *tt)
+open_tun (const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt)
 {
-  open_tun_generic (dev, dev_type, dev_node, ipv6, false, true, tt);
+  open_tun_generic (dev, dev_type, dev_node, false, true, tt);
 }
 
 void
diff --git a/tun.h b/tun.h
index 011ab54..f28b8d8 100644
--- a/tun.h
+++ b/tun.h
@@ -130,6 +130,7 @@ struct tuntap
   int topology; /* one of the TOP_x values */
 
   bool did_ifconfig_setup;
+  bool did_ifconfig_ipv6_setup;
   bool did_ifconfig;
 
   bool ipv6;
@@ -146,6 +147,10 @@ struct tuntap
   in_addr_t remote_netmask;
   in_addr_t broadcast;
 
+  struct in6_addr local_ipv6;
+  struct in6_addr remote_ipv6;
+  int netbits_ipv6;
+
 #ifdef WIN32
   HANDLE hand;
   struct overlapped_io reads;
@@ -197,7 +202,7 @@ tuntap_defined (const struct tuntap *tt)
 void clear_tuntap (struct tuntap *tuntap);
 
 void open_tun (const char *dev, const char *dev_type, const char *dev_node,
-	       bool ipv6, struct tuntap *tt);
+	       struct tuntap *tt);
 
 void close_tun (struct tuntap *tt);
 
@@ -206,7 +211,7 @@ int write_tun (struct tuntap* tt, uint8_t *buf, int len);
 int read_tun (struct tuntap* tt, uint8_t *buf, int len);
 
 void tuncfg (const char *dev, const char *dev_type, const char *dev_node,
-	     bool ipv6, int persist_mode, const char *username,
+	     int persist_mode, const char *username,
 	     const char *groupname, const struct tuntap_options *options);
 
 const char *guess_tuntap_dev (const char *dev,
@@ -219,6 +224,8 @@ struct tuntap *init_tun (const char *dev,       /* --dev option */
 			 int topology,          /* one of the TOP_x values */
 			 const char *ifconfig_local_parm,          /* --ifconfig parm 1 */
 			 const char *ifconfig_remote_netmask_parm, /* --ifconfig parm 2 */
+			 const char *ifconfig_ipv6_local_parm,     /* --ifconfig parm 1 / IPv6 */
+			 const char *ifconfig_ipv6_remote_parm,    /* --ifconfig parm 2 / IPv6 */
 			 in_addr_t local_public,
 			 in_addr_t remote_public,
 			 const bool strict_warn,
diff --git a/win32.c b/win32.c
index 2b7bf7b..cf6cc2d 100644
--- a/win32.c
+++ b/win32.c
@@ -874,16 +874,21 @@ win_safe_filename (const char *fn)
 static char *
 env_block (const struct env_set *es)
 {
+  char * force_path = "PATH=C:\\Windows\\System32;C:\\WINDOWS;C:\\WINDOWS\\System32\\Wbem";
+
   if (es)
     {
       struct env_item *e;
       char *ret;
       char *p;
       size_t nchars = 1;
+      bool path_seen = false;
       
       for (e = es->list; e != NULL; e = e->next)
 	nchars += strlen (e->string) + 1;
 
+      nchars += strlen(force_path)+1;
+
       ret = (char *) malloc (nchars);
       check_malloc_return (ret);
 
@@ -895,7 +900,18 @@ env_block (const struct env_set *es)
 	      strcpy (p, e->string);
 	      p += strlen (e->string) + 1;
 	    }
+	  if ( strncmp(e->string, "PATH=", 5 ) == 0 )
+	    path_seen = true;
+	}
+
+      /* make sure PATH is set */
+      if ( !path_seen )
+	{
+	  msg( M_INFO, "env_block: add %s", force_path );
+	  strcpy( p, force_path );
+	  p += strlen(force_path) + 1;
 	}
+
       *p = '\0';
       return ret;
     }
diff --git a/win32.h b/win32.h
index b6a162e..829933f 100644
--- a/win32.h
+++ b/win32.h
@@ -269,6 +269,8 @@ char *get_win_sys_path (void);
 
 /* call self in a subprocess */
 void fork_to_self (const char *cmdline);
+const char *inet_ntop(int af, const void *src, char *dst, socklen_t size);
+int inet_pton(int af, const char *src, void *st);
 
 /* Find temporary directory */
 const char *win_get_tempdir();