pass link_socket object to i/o functions

pass link_socket object to i/o functions

In order to prepare the code to work with distinct sockets,
it is essential that i/o functions do not operate on any
hard-coded socket object (i.e. c->c2.link_socket).

This patch changes all the low-level i/o functionis to work
with a socket specified as argument rather than a fixed one.

Change-Id: I8eae2d3356bbcc5d632eeb4fbe80de8009d9b40d
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Gianmarco De Gregori <gianmarco@mandelbit.com>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20241023083444.27951-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29603.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>