Class: DNS::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/faildns/client.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Client

Returns a new instance of Client.



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# File 'lib/faildns/client.rb', line 29

def initialize (options={})
  @options = options

  @servers = @options[:servers] || []

  if block_given?
    yield self
  end
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/faildns/client.rb', line 27

def options
  @options
end

#servers ⇒ Object (readonly)

Returns the value of attribute servers.



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# File 'lib/faildns/client.rb', line 27

def servers
  @servers
end

Instance Method Details

#query(message, timeout = 10) ⇒ Object 



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# File 'lib/faildns/client.rb', line 94

def query (message, timeout=10)
  result = []
  socket = UDPSocket.new

  @servers.each {|server|
    socket.connect(server.to_s, 53)

    socket.print message.pack

    if (tmp = Timeout.timeout(timeout) { socket.recvfrom(512) } rescue nil)
      DNS.debug tmp, { :level => 9 }

      result.push Message.parse(tmp[0])
    end
  }

  return result
end

#resolve(domain, timeout = 10, tries = 3) ⇒ Object 



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# File 'lib/faildns/client.rb', line 39

def resolve (domain, timeout=10, tries=3)
  result = nil
  socket = UDPSocket.new

  id = (rand * 100000).to_i % 65536

  1.upto(tries) {
    @servers.each {|server|
      socket.connect(server.to_s, 53)

      socket.print Message.new(
        Header.new {|h|
          h.id = id

          h.type  = :QUERY
          h.class = :QUERY

          h.recursive!

          h.questions = 1
        },

        [Question.new {|q|
          q.name = domain

          q.class = :IN
          q.type  = :A
        }]
      ).pack

      if (tmp = Timeout.timeout(timeout) { socket.recvfrom(512) } rescue nil)
        DNS.debug tmp, { :level => 9 }

        tmp = Message.parse(tmp[0])

        if tmp.header.status == :NXDOMAIN
          result = false
          break
        end

        if tmp.header.status == :NOERROR && tmp.header.id == id
          result = tmp.answers.find {|answer| answer.type == :A}.data.to_s rescue nil
          break
        end
      end
    }

    if !result.nil?
      break
    end
  }

  return result
end