class Rack::Protection::HostAuthorization

def initialize(*)
  super
  @permitted_hosts = []
  @domain_hosts = []
  @ip_hosts = []
  @all_permitted_hosts = Array(options[:permitted_hosts])
  @all_permitted_hosts.each do |host|
    case host
    when String
      if host.start_with?(DOT)
        domain = host[1..-1]
        @permitted_hosts << domain.downcase
        @domain_hosts << /\A#{SUBDOMAINS}#{Regexp.escape(domain)}\z/i
      else
        @permitted_hosts << host.downcase
      end
    when IPAddr then @ip_hosts << host
    end
  end
end