multipeer: introduce asymmetric peer-id

multipeer: introduce asymmetric peer-id

In order to achieve a multipeer functionality, peers now
use separate IDs for sending (tx_peer_id) and receiving
(rx_peer_id).

Each peer announces its own ID through pushing peer-info
using 'ID=7f1' hex format so identification can still
happen even if IP/port changes.

In P2P mode, peer switch to using the announced IDs after
mutual exchange.
In P2MP mode, clients always announce their ID, and servers
can optionally respond with their own to enable the same
behavior.

Change-Id: I0a13ee90b6706acf20eabcee3bab3f2dff639bf9
Signed-off-by: Gianmarco De Gregori <gianmarco@mandelbit.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1089
Message-Id: <20260728122355.2566-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg37944.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>