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



55
56
57
58
59
60
 
# 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.



62
63
64
 
# 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.



65
66
 
# 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) 


73
74
75
 
# 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.



78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
 
# 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]



129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
 
# 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 



68
69
70
 
# File 'lib/rubydns/server.rb', line 68

def shutdown
	fire(:stop)
end