Class: Async::DNS::Server

Inherits:
Object
  • Object
show all
Defined in:
lib/async/dns/server.rb

Constant Summary collapse

DEFAULT_ENDPOINTS =

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(endpoints = DEFAULT_ENDPOINTS, origin: '.', logger: Async.logger) ⇒ 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/async/dns/server.rb', line 39

def initialize(endpoints = DEFAULT_ENDPOINTS, origin: '.', logger: Async.logger)
	@endpoints = endpoints
	@origin = origin
	@logger = logger
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/async/dns/server.rb', line 48

def logger
  @logger
end

#origin ⇒ Object

Records are relative to this origin:



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# File 'lib/async/dns/server.rb', line 46

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/async/dns/server.rb', line 51

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/async/dns/server.rb', line 55

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/async/dns/server.rb', line 60

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) {"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) {"Skipping question #{question} #{resource_class} because #{$!}"}
			end
		end
	rescue StandardError => error
		@logger.error(query) {error}
		
		response.rcode = Resolv::DNS::RCode::ServFail
	end
	
	end_time = Time.now
	@logger.debug(query) {"Time to process request: #{end_time - start_time}s"}
	
	return response
end

#run(*args) ⇒ Object

Setup all specified interfaces and begin accepting incoming connections.



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# File 'lib/async/dns/server.rb', line 102

def run(*args)
	@logger.info "Starting Async::DNS server (v#{Async::DNS::VERSION})..."
	
	Async::Reactor.run do |task|
		fire(:setup)
		
		Async::IO::Endpoint.each(@endpoints) do |endpoint|
			task.async do
				endpoint.bind do |socket|
					case socket.type
					when Socket::SOCK_DGRAM
						@logger.info "<> Listening for datagrams on #{socket.local_address.inspect}"
						DatagramHandler.new(self, socket).run
					when Socket::SOCK_STREAM
						@logger.info "<> Listening for connections on #{socket.local_address.inspect}"
						StreamHandler.new(self, socket).run
					else
						raise ArgumentError.new("Don't know how to handle #{address}")
					end
				end
			end
		end
		
		fire(:start)
	end
end