enquiry on validation of dhcp offered address

[ching]

Hi all,

Does anyone knows how to validate an address offered by dhcp server?

e.g. i want dhclient to reject if offered address is in 10.0.0.0/8, 
172.16.0.0/12, 192.168.0.0/16
                                                or offered IPv6 prefix 
is in fc::00/7

Thanks
ching