iptables rule generator to allow US-based IP addresses

us-ips.rb

require 'csv'
require 'ipaddr'

last = nil
CSV.foreach("us.csv") do |row|
  next if row.empty?
  from = IPAddr.new(row[0])
  to = IPAddr.new(row[1])
  mask = from.to_i ^ to.to_i

  # count number of leading 0s
  count = 0
  32.times do |i|
    if mask & 1 == 1
      count = 0
    else
      count += 1
    end

    mask >>= 1
  end

  net = from.mask(count).to_range
  if last.nil?
    last = net
  else
    if last.end.succ == net.begin
      last = last.begin..net.end
    else
      puts "iptables -A INPUT -i eth0 -m iprange --src-range #{last.begin}-#{last.end} -m multiport --dports 80,443 -j ACCEPT"
      last = net
    end
  end
end
puts "iptables -A INPUT -i eth0 -m iprange --src-range #{last.begin}-#{last.end} -m multiport --dports 80,443 -j ACCEPT"

us.csv