From: Arne Schwabe Date: Sat, 1 Jan 2022 16:25:19 +0000 (+0100) Subject: Deprecate link-mtu X-Git-Tag: v2.6_beta1~301 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29453c37c1f3aa420a894996dd7be4a4f8393c5a;p=thirdparty%2Fopenvpn.git Deprecate link-mtu This options might have been useful in the past but nowadays it has a very unclear semantics, so better remove/deprecate it. Signed-off-by: Arne Schwabe Acked-by: Gert Doering Message-Id: <20220101162532.2251835-2-arne@rfc2549.org> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg23496.html Signed-off-by: Gert Doering --- diff --git a/doc/man-sections/link-options.rst b/doc/man-sections/link-options.rst index 32e72a1b7..b1ae4e75a 100644 --- a/doc/man-sections/link-options.rst +++ b/doc/man-sections/link-options.rst @@ -82,10 +82,15 @@ the local and the remote host. ping-restart 60 # Argument: timeout --link-mtu n - Sets an upper bound on the size of UDP packets which are sent between + **DEPRECATED** Sets an upper bound on the size of UDP packets which are sent between OpenVPN peers. *It's best not to set this parameter unless you know what you're doing.* + Due to variable header size of IP header (20 bytes for IPv4 and 40 bytes + for IPv6) and dynamically negotiated data channel cipher, this option + is not reliable. It is recommended to set tun-mtu with enough headroom + instead. + --local host Local host name or IP address for bind. If specified, OpenVPN will bind to this address only. If unspecified, OpenVPN will bind to all diff --git a/src/openvpn/options.c b/src/openvpn/options.c index 7d48d6f2a..32ba34aa9 100644 --- a/src/openvpn/options.c +++ b/src/openvpn/options.c @@ -2112,9 +2112,7 @@ options_postprocess_verify_ce(const struct options *options, */ if (options->ce.tun_mtu_defined && options->ce.link_mtu_defined) { - msg(M_USAGE, - "only one of --tun-mtu or --link-mtu may be defined (note that " - "--ifconfig implies --link-mtu %d)", LINK_MTU_DEFAULT); + msg(M_USAGE, "only one of --tun-mtu or --link-mtu may be defined"); } if (!proto_is_udp(ce->proto) && options->mtu_test)