Remove saving initial frame code

Remove saving initial frame code

This code was necessary before the frame/buffer refactoring as we
always did relative adjustment to the frame.

This also fixes also that previously initial_frame was initialised too
early before the fragment related options were initialised and contained
0 for the maximum frame size. This resulted in a DIV by 0 that caused an
abort on platforms that throw an exception for that.

CVE: 2023-46849

Only people with --fragment in their config are affected

Change-Id: Icc612bab5700879606290639e1b8773f61ec670d
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: David Sommerseth <davids@openvpn.net>
Acked-by: Heiko Hund <heiko@ist.eigentlich.net>
Message-Id: <20231108124947.76816-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/search?l=mid&q=20231108124947.76816-1-gert@greenie.muc.de
Signed-off-by: Gert Doering <gert@greenie.muc.de>