Class: RubyDNS::Server

Inherits:
Object
  • Object
show all
Includes:
Celluloid::IO
Defined in:
lib/rubydns/server.rb

Direct Known Subclasses

RuleBasedServer

Constant Summary collapse

DEFAULT_INTERFACES =

The default server interfaces

[[:udp, "0.0.0.0", 53], [:tcp, "0.0.0.0", 53]]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Server

Instantiate a server with a block

server = Server.new do match(/server.mydomain.com/, IN::A) do |transaction| transaction.respond!("1.2.3.4") end end



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# File 'lib/rubydns/server.rb', line 55

def initialize(options = {})
  @handlers = []
  
  @logger = options[:logger] || Celluloid.logger
  @interfaces = options[:listen] || DEFAULT_INTERFACES
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/rubydns/server.rb', line 62

def logger
  @logger
end

Instance Method Details

#fire(event_name) ⇒ Object

Fire the named event as part of running the server.



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# File 'lib/rubydns/server.rb', line 65

def fire(event_name)
end

#process(name, resource_class, transaction) ⇒ Object

Give a name and a record type, try to match a rule and use it for processing the given arguments.

Raises:

  • (NotImplementedError) 


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# File 'lib/rubydns/server.rb', line 73

def process(name, resource_class, transaction)
  raise NotImplementedError.new
end

#process_query(query, options = {}, &block) ⇒ Object

Process an incoming DNS message. Returns a serialized message to be sent back to the client.



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# File 'lib/rubydns/server.rb', line 78

def process_query(query, options = {}, &block)
  start_time = Time.now
  
  # Setup response
  response = Resolv::DNS::Message::new(query.id)
  response.qr = 1                 # 0 = Query, 1 = Response
  response.opcode = query.opcode  # Type of Query; copy from query
  response.aa = 1                 # Is this an authoritative response: 0 = No, 1 = Yes
  response.rd = query.rd          # Is Recursion Desired, copied from query
  response.ra = 0                 # Does name server support recursion: 0 = No, 1 = Yes
  response.rcode = 0              # Response code: 0 = No errors
  
  transaction = nil
  
  begin
    query.question.each do |question, resource_class|
      @logger.debug {"<#{query.id}> Processing question #{question} #{resource_class}..."}
  
      transaction = Transaction.new(self, query, question, resource_class, response, options)
      
      transaction.process
    end
  rescue Celluloid::ResumableError
    raise
  rescue StandardError => error
    @logger.error "<#{query.id}> Exception thrown while processing #{transaction}!"
    RubyDNS.log_exception(@logger, error)
  
    response.rcode = Resolv::DNS::RCode::ServFail
  end
  
  end_time = Time.now
  @logger.debug {"<#{query.id}> Time to process request: #{end_time - start_time}s"}
  
  return response
end

#run ⇒ Object

By default the server runs on port 53, both TCP and UDP, which is usually a priviledged port and requires root access to bind. You can change this by specifying options[:listen] which should contain an array of [protocol, interface address, port] specifications.

INTERFACES = [[:udp, "0.0.0.0", 5300]] RubyDNS::run_server(:listen => INTERFACES) do ... end

You can specify already connected sockets if need be:

socket = UDPSocket.new; socket.bind("0.0.0.0", 53) Process::Sys.setuid(server_uid) INTERFACES = [socket]



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# File 'lib/rubydns/server.rb', line 129

def run
  @logger.info "Starting RubyDNS server (v#{RubyDNS::VERSION})..."
  
  fire(:setup)
  
  # Setup server sockets
  @interfaces.each do |spec|
    if spec.is_a?(BasicSocket)
      spec.do_not_reverse_lookup
      protocol = spec.getsockopt(Socket::SOL_SOCKET, Socket::SO_TYPE).unpack("i")[0]
      ip = spec.local_address.ip_address
      port = spec.local_address.ip_port
      
      case protocol
      when Socket::SOCK_DGRAM
        @logger.info "<> Attaching to pre-existing UDP socket #{ip}:#{port}"
        link UDPSocketHandler.new(self, UDPSocketWrapper.new(spec))
      when Socket::SOCK_STREAM
        @logger.info "<> Attaching to pre-existing TCP socket #{ip}:#{port}"
        link TCPSocketHandler.new(self, TCPServerWrapper.new(spec))
      else
        raise ArgumentError.new("Unknown socket protocol: #{protocol}")
      end
    elsif spec[0] == :udp
      @logger.info "<> Listening on #{spec.join(':')}"
      link UDPHandler.new(self, spec[1], spec[2])
    elsif spec[0] == :tcp
      @logger.info "<> Listening on #{spec.join(':')}"
      link TCPHandler.new(self, spec[1], spec[2])
    else
      raise ArgumentError.new("Invalid connection specification: #{spec.inspect}")
    end
  end
  
  fire(:start)
end

#shutdown ⇒ Object 



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# File 'lib/rubydns/server.rb', line 68

def shutdown
  fire(:stop)
end