socketry/rubydns

#!/usr/bin/env ruby

# Copyright, 2009, 2012, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require 'rubygems'
require 'rubydns'

$R = Resolv::DNS.new
Name = Resolv::DNS::Name
IN = Resolv::DNS::Resource::IN

RubyDNS.run_server([[:udp, '0.0.0.0', 5400]]) do
    # SOA Record
    #   dig @localhost -p 5400 SOA mydomain.org
    match('mydomain.org', IN::SOA) do |transaction|
        #
        # For more details about these headers please see:
        #   http://www.ripe.net/ripe/docs/ripe-203.html
        #
        
        transaction.respond!(
            Name.create('ns.mydomain.org.'),    # Master Name
            Name.create('admin.mydomain.org.'), # Responsible Name
            File.mtime(__FILE__).to_i,          # Serial Number
            1200,                               # Refresh Time
            900,                                # Retry Time
            3_600_000,                          # Maximum TTL / Expiry Time
            172_800                             # Minimum TTL
        )
        
        transaction.append!(transaction.question, IN::NS, section: :authority)
    end

    # Default NS record
    #   dig @localhost -p 5400 mydomain.org NS
    match('mydomain.org', IN::NS) do |transaction|
        transaction.respond!(Name.create('ns.mydomain.org.'))
    end

    # For this exact address record, return an IP address
    #   dig @localhost -p 5400 CNAME bob.mydomain.org
    match(/([^.]+).mydomain.org/, IN::CNAME) do |transaction|
        transaction.respond!(Name.create('www.mydomain.org'))
        transaction.append!('www.mydomain.org', IN::A)
    end

    match('80.0.0.10.in-addr.arpa', IN::PTR) do |transaction|
        transaction.respond!(Name.create('www.mydomain.org.'))
    end

    match('www.mydomain.org', IN::A) do |transaction|
        transaction.respond!('10.0.0.80')
    end

    match('ns.mydomain.org', IN::A) do |transaction|
        transaction.respond!('10.0.0.10')
    end

    # Default DNS handler
    otherwise do |transaction|
        # Non-Existant Domain
        transaction.fail!(:NXDomain)
    end
end