[strongSwan] Set up strongswan in hub-and-spoke topology

[unite]

Hi guys!

Is there a way to configure strongswan in a site-to-site hub-and-spoke 
topology, so for me to have for example strongswan hub in central office 
and having multiple spokes whose traffic between each other should be 
routed through the central office? I haven't found a guide on the net, 
so it would be very helpful for me if you can point me to the one, or 
just explain how can I configure my tunnels in such a way.

Also, I guess pretty similar question, can I configure clients in 
spoke's network to use central office as a default gateway, so their 
traffic should be routed encrypted to the central office, then decrypted 
and sent to the receiver?

Thnaks in advance.

-- 
With kind regards,
Aleksey