In: |
resolv.rb
|
Parent: | Object |
# File resolv.rb, line 1147 def initialize(data) @data = data @index = 0 @limit = data.length yield self end
# File resolv.rb, line 1154 def get_length16 len, = self.get_unpack('n') save_limit = @limit @limit = @index + len d = yield(len) if @index < @limit raise DecodeError.new("junk exist") elsif @limit < @index raise DecodeError.new("limit exceed") end @limit = save_limit return d end
# File resolv.rb, line 1168 def get_bytes(len = @limit - @index) d = @data[@index, len] @index += len return d end
# File resolv.rb, line 1174 def get_unpack(template) len = 0 template.each_byte {|byte| case byte when ?c, ?C len += 1 when ?n len += 2 when ?N len += 4 else raise StandardError.new("unsupported template: '#{byte.chr}' in '#{template}'") end } raise DecodeError.new("limit exceed") if @limit < @index + len arr = @data.unpack("@#{@index}#{template}") @index += len return arr end
# File resolv.rb, line 1194 def get_string len = @data[@index] raise DecodeError.new("limit exceed") if @limit < @index + 1 + len d = @data[@index + 1, len] @index += 1 + len return d end
# File resolv.rb, line 1206 def get_labels(limit=nil) limit = @index if !limit || @index < limit d = [] while true case @data[@index] when 0 @index += 1 return d when 192..255 idx = self.get_unpack('n')[0] & 0x3fff if limit <= idx raise DecodeError.new("non-backward name pointer") end save_index = @index @index = idx d += self.get_labels(limit) @index = save_index return d else d << self.get_label end end return d end