Class: Dnsruby::RR::TXT

Inherits:
Dnsruby::RR show all
Defined in:
lib/dnsruby/resource/TXT.rb

Overview

Class for DNS Text (TXT) resource records. RFC 1035 Section 3.3.14

Direct Known Subclasses

SPF

Constant Summary collapse

ClassValue =

:nodoc: all

nil
TypeValue =

:nodoc: all

Types::TXT
ESCAPE_CHARS = 
{"b" => 8, "t" => 9, "n" => 10, "v" => 11, "f" => 12, "r" => 13}
ESCAPE_CODES = 
ESCAPE_CHARS.invert

Constants inherited from Dnsruby::RR

ClassInsensitiveTypes

Instance Attribute Summary collapse

Attributes inherited from Dnsruby::RR

#klass, #name, #rdata, #ttl, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Dnsruby::RR

#<=>, #==, #clone, create, #eql?, find_class, get_class, get_num, #hash, implemented_rrs, #init_defaults, new_from_data, new_from_hash, new_from_string, #rdlength, #sameRRset, #to_s

Instance Attribute Details

#strings ⇒ Object

List of the individual elements



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# File 'lib/dnsruby/resource/TXT.rb', line 29

def strings
  @strings
end

Class Method Details

.decode_rdata(msg) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/TXT.rb', line 196

def self.decode_rdata(msg) #:nodoc: all
  strings = msg.get_string_list
  return self.new(strings)
end

.display(str, do_escapes = true) ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 150

def TXT.display(str, do_escapes = true)
  output = ""
  #  Probably need to scan through each string manually
  #  Make sure to remember to escape binary characters.
  #  Go through copying to output, and adding "\" characters as necessary?
  str.each_byte {|c|
    if (c == 34) || (c == 92) # || (c == 59)
      if (do_escapes)
      output+='\\'
      end
      output+=c.chr
    elsif (c < 32) # c is binary
      if (ESCAPE_CODES[c])
        output +=  c.chr
      else
        output+= '\\'
        num = c.to_i.to_s
        (3-num.length).times {|i|
          num="0"+num
        }
        output+= num # Need a 3 digit number here.
      end

    else
      output += c.chr
    end
  }
  return output
end

.parse(input) ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 52

def TXT.parse(input)
  #  Need to look out for special characters.
  #  Need to split the input up into strings (which are defined by non-escaped " characters)
  #  Then need to fix up any \ escape characters (should just be " and ; and binary?)
  #  Sadly, it's going to be easiest just to scan through this character by character...
  in_escaped = false
  in_string = false
  count = -1
  strings = []
  current_binary = ""
  current_quote_char = '"'
  unquoted = false
  seen_strings = false
  pos = 0
  input = input.sub(/^\s*\(\s*/, "")
  input.sub!(/\s*\)\s*$/, "")
  input.each_char {|c|
    if (((c == "'") || (c == '"')) && (!in_escaped) && (!unquoted))
      if (!in_string)
        seen_strings = true
        current_quote_char = c
        in_string = true
        count+=1
        strings[count] = ""
      else
        if (c == current_quote_char)
          in_string = false
        else
          strings[count]+=c
        end
      end
    else
      if (seen_strings && !in_string)
        if (c == ";")
           # Comment in zone file!
           return strings
        end
        if (c != " " && c != "\t")
          in_string = true
          count+=1
          strings[count] = ""
        else
          next
        end
      end
      if (pos == 0)
        unquoted = true
        count+=1
        strings[count] = ""
      elsif (unquoted)
        if (c == " ")
          count+=1
          strings[count] = ""
          pos += 1
          next
        end
      end

      if (c == "\\")
        if (in_escaped)
          in_escaped = false
          strings[count]+=(c)
        else
          in_escaped = true
        end
      else
        if (in_escaped)
          #  Build up the binary
          if (c == ";") || (c == '"')
            strings[count]+=c
            in_escaped = false
          elsif (ESCAPE_CHARS[c])
            in_escaped=false
            strings[count]+=ESCAPE_CHARS[c].chr
          elsif (c<"0" || c>"9")
            in_escaped = false
            strings[count]+=c
          else
            #  Must be building up three digit string to identify binary value?
#                  if (c >= "0" && c <= "9")
              current_binary += c
#                  end
            if ((current_binary.length == 3) ) # || (c < "0" || c > "9"))
              strings[count]+=current_binary.to_i.chr
              in_escaped = false
              current_binary = ""
            end
          end
        else
          strings[count]+=(c)
        end
      end
    end
    pos += 1
  }
  return strings
end

Instance Method Details

#data ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 31

def data
  @strings.join
end

#encode_rdata(msg, canonical = false) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/TXT.rb', line 192

def encode_rdata(msg, canonical=false) #:nodoc: all
  msg.put_string_list(@strings)
end

#from_data(data) ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 35

def from_data(data)
  @strings = data
end

#from_hash(hash) ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 39

def from_hash(hash)
  if (hash.has_key?:strings)
    from_string(hash[:strings])
  end
end

#from_string(input) ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 48

def from_string(input)
  @strings = TXT.parse(input)
end

#rdata_to_string ⇒ Object 



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# File 'lib/dnsruby/resource/TXT.rb', line 180

def rdata_to_string
  if (defined?@strings)
    temp = []
    @strings.each {|str|
      output = TXT.display(str)
      temp.push("\"#{output}\"")
    }
    return temp.join(' ')
  end
  return ''
end