Verify facebook crawler ip range.

facebook_ip_range.rb

require 'ipaddr'

class FacebookIPRange
  def self.zones
    @@zones ||= build_zones
  end

  def self.match(ipaddr)
    zones.each do |zone|
      return true if zone === ipaddr
    end
    false
  end

  def self.build_zones
    zones = []
    lines = `whois -h whois.radb.net -- '-i origin AS32934' | grep ^route`.split(/\n/)
    lines.each do |line|
      if line =~ /route:\s*(\d+\.\d+\.\d+\.\d+\/\d+)/
        zones << $1
      end
    end
    zones_to_ipaddrs zones
  end
  def self.zones_to_ipaddrs(zones)
    zones.map { |zone| IPAddr.new zone }
  end
end