gistfile1.lua

whitelist = { "google.com.", "cnn.com." }

function preresolve(remoteip, domain, qtype)
   if (domain == ".") then
      return -1, {}
   end 
   -- skip top level domains
   if (string.match(domain,"^[^.]+.?$")) then
      return -1, {}
   end 

   -- expensive
   for _,dom in pairs(whitelist) do
     local sub = string.sub(domain, -1 * string.len(dom))
     if (sub == dom) then
       return -1, {}
     end
   end

   return 0, {{qtype=pdns.CNAME, content="www.forbidden.com"}}
end