[Openswan Users] Dynamically attached interfaces

[Siegfried Vogl]

Hello,


Linux Openswan U2.6.52.1/K4.14.214 on an embedded system.

I'm a bit confused because I always thought that openswan automatically 
recognizes interfaces that are added at runtime or whose ip address 
changes dynamically.

Now I have the following issue:
- pluto has started.

- "networkd" from "systemd" (version 246) is used as the network daemon. 
I cannot use the NetworkManager.

- An OTA connection is started via the command line interface of the 
ModemManager ("mmcli -m <modem> --simple-connect=..."), which creates 
the interface "wwan0".


Openswan does not set up a listener on this interface. Only an "ipsec 
whack --listen" makes the interface known to Pluto. The disadvantage 
here is that tunnels that are active on other interfaces are then 
obviously terminated.
Even if the wwan0 interface is already known to Pluto, but changes its 
IP due to a new connection, this is not recognized by Pluto. When 
starting a tunnel, this then leads to a routing problem in Pluto because 
it does not recognize the new network.
I am now wondering whether this is due to the use of the "systemd networkd"?

Workarounds:
- Does anyone know of a command to specifically add or remove an 
interface for the listener? I don't know anyone.
- Let Pluto listen on a bridge interface and add the wwan to the bridge 
during runtime, or delete it.

By the way, the problem is not limited to OTA. I have the same problem 
on a LAN DHCP interface.

I would be grateful for any advice.

Siegfried