Class: Async::DNS::DatagramHandler

Inherits:
GenericHandler show all
Defined in:
lib/async/dns/handler.rb

Overview

Handle incoming UDP requests, which are single data packets, and pass them on to the given server.

Instance Attribute Summary

Attributes inherited from GenericHandler

#The server that will process incoming queries., #server, #socket

Instance Method Summary collapse

Methods inherited from GenericHandler

#The socket to read/write data from/to.=, #error_response, #initialize, #process_query

Constructor Details

This class inherits a constructor from Async::DNS::GenericHandler

Instance Method Details

#respond(socket, input_data, remote_address) ⇒ Object

Respond to an incoming query.



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# File 'lib/async/dns/handler.rb', line 92

def respond(socket, input_data, remote_address)
	response = process_query(input_data, remote_address: remote_address)
	
	output_data = response.encode
	
	Console.debug "Writing #{output_data.bytesize} bytes response to client via UDP...", response_id: response.id
	
	if output_data.bytesize > UDP_REASONABLE_SIZE
		Console.warn "Response via UDP was larger than #{UDP_REASONABLE_SIZE}!", response_id: response.id
		
		# Reencode data with truncation flag marked as true:
		truncation_error = Resolv::DNS::Message.new(response.id)
		truncation_error.tc = 1
		
		output_data = truncation_error.encode
	end
	
	socket.sendmsg(output_data, 0, remote_address)
rescue IOError => error
	Console.error(self, "UDP response failed!", error: error)
rescue EOFError => error
	Console.error(self, "UDP session ended prematurely!", error: error)
rescue Resolv::DNS::DecodeError => error
	Console.error(self, "Could not decode incoming UDP data!", error: error)
end

#run(wrapper = ::IO::Endpoint::Wrapper.default) ⇒ Object

Run the handler, processing incoming UDP requests.



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# File 'lib/async/dns/handler.rb', line 81

def run(wrapper = ::IO::Endpoint::Wrapper.default)
	while true
		input_data, remote_address = @socket.recvmsg(UDP_MAXIMUM_SIZE)
		
		wrapper.async do
			respond(@socket, input_data, remote_address)
		end
	end
end