Client derived CoA/DM home servers

[Arran Cudbard-Bell]

In v3.0.x CoA/DM home servers may now be specified as part of a client definition.

Previously a coa home_server could be associated with a client using the coa_server 
config pair to specify the name of a coa home_server or pool.

This functionality is extended, so that if coa_server is specified as a config 
section a new coa home_server is created, and inherits pairs from the client 
definition.

For example:

client localhost {
        coa_server {
                port = 1700
                zombie_period = 50

                coa {
                        irt = 10
                }   
        }   

        ipaddr = 127.0.0.1
        secret = testing123
}

would add a home_server with the ipaddr 127.0.0.1 and the secret testing123 on port 1700,
If no port is specified 3799 is used.

An empty coa_server section may also be used if no values need to be altered.

client localhost {
        coa_server { 
        }   

        ipaddr = 127.0.0.1
        secret = testing123
}

and values from the client definition can be overridden.

client localhost {
        coa_server {
		secret = 123testing 
        }   

        ipaddr = 127.0.0.1
        secret = testing123
}

The coa_server section isn't restricted to clients.conf and should work fine with rlm_ldap 
and rlm_couchbase too.

If there's demand for it a global knob can be added so that coa home_server definitions are 
added automatically for all clients.

Client derived home_servers will conflict with home_servers defined in proxy.conf if two 
share the same type/port/ipaddr, but they won't conflict on name as they're unnamed.
This also means they can't be referenced in pools.

Arran Cudbard-Bell <a.cudbardb at freeradius.org>
FreeRADIUS development team

FD31 3077 42EC 7FCD 32FE 5EE2 56CF 27F9 30A8 CAA2