class Rack::Protection::IPSpoofing

def accepts?(env)
  return true unless env.include? 'HTTP_X_FORWARDED_FOR'
  ips = env['HTTP_X_FORWARDED_FOR'].split(',').map(&:strip)
  return false if env.include?('HTTP_CLIENT_IP') && (!ips.include? env['HTTP_CLIENT_IP'])
  return false if env.include?('HTTP_X_REAL_IP') && (!ips.include? env['HTTP_X_REAL_IP'])
  true
end