DNS Logger

dns_logger.rb

# encoding: utf-8
require 'rubygems'
require 'rubydns'
require 'yaml'
require 'socket'
require 'awesome_print'
require 'logger'

if RExec.current_user != "root"
  $stderr.puts "Sorry, this command needs to be run as root!"
  exit 1
end

YAML::ENGINE.yamler='syck'  # 防止出现 !binary
INTERFACES = [[:udp, "0.0.0.0", 53], [:tcp, "0.0.0.0", 53]]
Name = Resolv::DNS::Name
IN = Resolv::DNS::Resource::IN
UPSTREAM = RubyDNS::Resolver.new([[:tcp, "8.8.8.8", 53]], :timeout => 1)
# UPSTREAM = RubyDNS::Resolver.new([[:udp, "10.10.0.21", 53]], :timeout => 3)

def self.run
  # Start the RubyDNS server
  RubyDNS::run_server(:listen => INTERFACES) do

    on(:start) do
      # @logger.level = Logger::DEBUG
      @logger.level = Logger::WARN
    end

    # deny IPv6
    match(/.*/, IN::AAAA) do |transaction|
      transaction.failure!(:NXDomain)
    end

    # passthrough & log everything
    match(/.*/, IN::A) do |transaction|
      domain = transaction.name.to_s
      transaction.passthrough!(UPSTREAM) do |reply|
        unless reply.answer.nil? || reply.answer.last.nil?
          address = reply.answer.last.last.address.to_s
          d = YAML::load_file('log.yml') #Load
          d[domain] = address #Modify
          puts domain
          puts address
          File.write('log.yml', d.to_yaml) #Store      
        end
      end
    end
  end
end
run