Resolv::DNS::Config ^(Class)

# File resolv.rb, line 746
      def Config.default_config_hash(filename="/etc/resolv.conf")
        if File.exist? filename
          config_hash = Config.parse_resolv_conf(filename)
        else
          if /mswin32|cygwin|mingw|bccwin/ =~ RUBY_PLATFORM
            search, nameserver = Win32::Resolv.get_resolv_info
            config_hash = {}
            config_hash[:nameserver] = nameserver if nameserver
            config_hash[:search] = [search] if search
          end
        end
        config_hash
      end

# File resolv.rb, line 715
      def initialize(config_info=nil)
        @mutex = Mutex.new
        @config_info = config_info
        @initialized = nil
      end

# File resolv.rb, line 721
      def Config.parse_resolv_conf(filename)
        nameserver = []
        search = nil
        ndots = 1
        open(filename) {|f|
          f.each {|line|
            line.sub!(/[#;].*/, '')
            keyword, *args = line.split(/\s+/)
            args.each { |arg|
              arg.untaint
            }
            next unless keyword
            case keyword
            when 'nameserver'
              nameserver += args
            when 'domain'
              search = [args[0]]
            when 'search'
              search = args
            end
          }
        }
        return { :nameserver => nameserver, :search => search, :ndots => ndots }
      end

# File resolv.rb, line 826
      def generate_candidates(name)
        candidates = nil
        name = Name.create(name)
        if name.absolute?
          candidates = [name]
        else
          if @ndots <= name.length - 1
            candidates = [Name.new(name.to_a)]
          else
            candidates = []
          end
          candidates.concat(@search.map {|domain| Name.new(name.to_a + domain)})
        end
        return candidates
      end

# File resolv.rb, line 844
      def generate_timeouts
        ts = [InitialTimeout]
        ts << ts[-1] * 2 / @nameserver.length
        ts << ts[-1] * 2
        ts << ts[-1] * 2
        return ts
      end

# File resolv.rb, line 760
      def lazy_initialize
        @mutex.synchronize {
          unless @initialized
            @nameserver = []
            @search = nil
            @ndots = 1
            case @config_info
            when nil
              config_hash = Config.default_config_hash
            when String
              config_hash = Config.parse_resolv_conf(@config_info)
            when Hash
              config_hash = @config_info.dup
              if String === config_hash[:nameserver]
                config_hash[:nameserver] = [config_hash[:nameserver]]
              end
              if String === config_hash[:search]
                config_hash[:search] = [config_hash[:search]]
              end
            else
              raise ArgumentError.new("invalid resolv configuration: #{@config_info.inspect}")
            end
            @nameserver = config_hash[:nameserver] if config_hash.include? :nameserver
            @search = config_hash[:search] if config_hash.include? :search
            @ndots = config_hash[:ndots] if config_hash.include? :ndots

            @nameserver = ['0.0.0.0'] if @nameserver.empty?
            if @search
              @search = @search.map {|arg| Label.split(arg) }
            else
              hostname = Socket.gethostname
              if /\./ =~ hostname
                @search = [Label.split($')]
              else
                @search = [[]]
              end
            end

            if !@nameserver.kind_of?(Array) ||
               !@nameserver.all? {|ns| String === ns }
              raise ArgumentError.new("invalid nameserver config: #{@nameserver.inspect}")
            end

            if !@search.kind_of?(Array) ||
               !@search.all? {|ls| ls.all? {|l| Label::Str === l } }
              raise ArgumentError.new("invalid search config: #{@search.inspect}")
            end

            if !@ndots.kind_of?(Integer)
              raise ArgumentError.new("invalid ndots config: #{@ndots.inspect}")
            end

            @initialized = true
          end
        }
      end

# File resolv.rb, line 852
      def resolv(name)
        candidates = generate_candidates(name)
        timeouts = generate_timeouts
        begin
          candidates.each {|candidate|
            begin
              timeouts.each {|tout|
                @nameserver.each {|nameserver|
                  begin
                    yield candidate, tout, nameserver
                  rescue ResolvTimeout
                  end
                }
              }
              raise ResolvError.new("DNS resolv timeout: #{name}")
            rescue NXDomain
            end
          }
        rescue OtherResolvError
          raise ResolvError.new("DNS error: #{$!.message}")
        end
        raise ResolvError.new("DNS resolv error: #{name}")
      end

# File resolv.rb, line 817
      def single?
        lazy_initialize
        if @nameserver.length == 1
          return @nameserver[0]
        else
          return nil
        end
      end