@@ -128,6 +128,8 @@ User-visible Changes

 - CHACHA20-POLY1305 is included in the default of ``--data-ciphers`` when available.

 - Option ``--prng`` is ignored as we rely on the SSL library random number generator.

 - Option ``--nobind`` is default when ``--client`` or ``--pull`` is used in the configuration

+- :code:`link_mtu` parameter is removed from environment or replaced with 0 when scripts are

+  called with parameters. This parameter is unreliable and no longer internally calculated.

 Overview of changes in 2.5

 ==========================

@@ -376,15 +376,17 @@ SCRIPT HOOKS

   For ``--dev tun`` execute as:

   ::

-      cmd tun_dev tun_mtu link_mtu ifconfig_local_ip ifconfig_remote_ip [init | restart]

+      cmd tun_dev tun_mtu 0 ifconfig_local_ip ifconfig_remote_ip [init | restart]

   For ``--dev tap`` execute as:

   ::

-       cmd tap_dev tap_mtu link_mtu ifconfig_local_ip ifconfig_netmask [init | restart]

+       cmd tap_dev tap_mtu 0 ifconfig_local_ip ifconfig_netmask [init | restart]

   See the `Environmental Variables`_ section below for additional

-  parameters passed as environmental variables.

+  parameters passed as environmental variables.  The ``0`` argument

+  used to be ``link_mtu`` which is no longer passed to scripts - to

+  keep the argument order, it was replaced with ``0``.

   Note that if ``cmd`` includes arguments, all OpenVPN-generated arguments

   will be appended to them to build an argument list with which the

@@ -664,9 +666,9 @@ instances.

     ``--client-connect`` and ``--client-disconnect`` scripts.

 :code:`link_mtu`

-    The maximum packet size (not including the IP header) of tunnel data in

-    UDP tunnel transport mode. Set prior to ``--up`` or ``--down`` script

-    execution.

+    No longer passed to scripts since OpenVPN 2.6.0.  Used to be the

+    maximum packet size (not including the IP header) of tunnel data in

+    UDP tunnel transport mode.

 :code:`local`

     The ``--local`` parameter. Set on program initiation and reset on

@@ -113,7 +113,6 @@ run_up_down(const char *command,

 #endif

             const char *dev_type,

             int tun_mtu,

-            int link_mtu,

             const char *ifconfig_local,

             const char *ifconfig_remote,

             const char *context,

@@ -129,7 +128,6 @@ run_up_down(const char *command,

     }

     setenv_str(es, "script_context", context);

     setenv_int(es, "tun_mtu", tun_mtu);

-    setenv_int(es, "link_mtu", link_mtu);

     setenv_str(es, "dev", arg);

     if (dev_type)

     {

@@ -157,11 +155,8 @@ run_up_down(const char *command,

         struct argv argv = argv_new();

         ASSERT(arg);

         argv_printf(&argv,

-                    "%s %d %d %s %s %s",

-                    arg,

-                    tun_mtu, link_mtu,

-                    ifconfig_local, ifconfig_remote,

-                    context);

+                    "%s %d 0 %s %s %s",

+                    arg, tun_mtu, ifconfig_local, ifconfig_remote, context);

         if (plugin_call(plugins, plugin_type, &argv, NULL, es) != OPENVPN_PLUGIN_FUNC_SUCCESS)

         {

@@ -177,7 +172,7 @@ run_up_down(const char *command,

         ASSERT(arg);

         setenv_str(es, "script_type", script_type);

         argv_parse_cmd(&argv, command);

-        argv_printf_cat(&argv, "%s %d %d %s %s %s", arg, tun_mtu, link_mtu,

+        argv_printf_cat(&argv, "%s %d 0 %s %s %s", arg, tun_mtu,

                         ifconfig_local, ifconfig_remote, context);

         argv_msg(M_INFO, &argv);

         openvpn_run_script(&argv, es, S_FATAL, "--up/--down");

@@ -1784,7 +1779,6 @@ do_open_tun(struct context *c)

 #endif

                 dev_type_string(c->options.dev, c->options.dev_type),

                 TUN_MTU_SIZE(&c->c2.frame),

-                EXPANDED_SIZE(&c->c2.frame),

                 print_in_addr_t(c->c1.tuntap->local, IA_EMPTY_IF_UNDEF, &gc),

                 print_in_addr_t(c->c1.tuntap->remote_netmask, IA_EMPTY_IF_UNDEF, &gc),

                 "init",

@@ -1834,7 +1828,6 @@ else

 #endif

                     dev_type_string(c->options.dev, c->options.dev_type),

                     TUN_MTU_SIZE(&c->c2.frame),

-                    EXPANDED_SIZE(&c->c2.frame),

                     print_in_addr_t(c->c1.tuntap->local, IA_EMPTY_IF_UNDEF, &gc),

                     print_in_addr_t(c->c1.tuntap->remote_netmask, IA_EMPTY_IF_UNDEF, &gc),

                     "restart",

@@ -1914,7 +1907,6 @@ do_close_tun(struct context *c, bool force)

 #endif

                             NULL,

                             TUN_MTU_SIZE(&c->c2.frame),

-                            EXPANDED_SIZE(&c->c2.frame),

                             print_in_addr_t(local, IA_EMPTY_IF_UNDEF, &gc),

                             print_in_addr_t(remote_netmask, IA_EMPTY_IF_UNDEF, &gc),

                             "init",

@@ -1945,7 +1937,6 @@ do_close_tun(struct context *c, bool force)

 #endif

                         NULL,

                         TUN_MTU_SIZE(&c->c2.frame),

-                        EXPANDED_SIZE(&c->c2.frame),

                         print_in_addr_t(local, IA_EMPTY_IF_UNDEF, &gc),

                         print_in_addr_t(remote_netmask, IA_EMPTY_IF_UNDEF, &gc),

                         "init",

@@ -1984,7 +1975,6 @@ do_close_tun(struct context *c, bool force)

 #endif

                             NULL,

                             TUN_MTU_SIZE(&c->c2.frame),

-                            EXPANDED_SIZE(&c->c2.frame),

                             print_in_addr_t(local, IA_EMPTY_IF_UNDEF, &gc),

                             print_in_addr_t(remote_netmask, IA_EMPTY_IF_UNDEF, &gc),

                             "restart",