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
	
	@origin = options[:origin] || '.'
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/rubydns/server.rb', line 67

def logger
  @logger
end

#origin ⇒ Object

Records are relative to this origin:



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

def origin
  @origin
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 70

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 78

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 83

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|
			begin
				question = question.without_origin(@origin)
				
				@logger.debug {"<#{query.id}> Processing question #{question} #{resource_class}..."}
				
				transaction = Transaction.new(self, query, question, resource_class, response, options)
				
				transaction.process
			rescue Resolv::DNS::OriginError
				# This is triggered if the question is not part of the specified @origin:
				@logger.debug {"<#{query.id}> Skipping question #{question} #{resource_class} because #{$!}"}
			end
		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 141

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 73

def shutdown
	fire(:stop)
end