[strongSwan] Clients with identical networks?

[Jakob Curdes]

.. I have done quite a bit of research but I did not find a description 
for my layout; or at least I did not find one which I understand to 
describe my problem.

I (will) have several roadwarriors with the same internal subnet; they 
will all have to connect to one central IPSec hub. I need connectivity 
in both directions, so a source NAT (done e.g. by updown script) does 
not really help here as far as I see. I know that e.g. with Cisco you 
can do a "two-way NAT" thing so that we can distinguish the subnets by 
moving them on the client side. What would a solution with IPSec tools 
look like?

Regards,
Jakob Curdes