Name of the RR

Data belonging to that appropriate class, not to be used (use real accessors instead)

TTL time (in seconds) of the RR

Create a new instance of Net::DNS::RR class, or an instance of any of the subclass of the appropriate type.

Argument can be a string or an hash. With a sting, we can pass a RR resource record in the canonical format:

a     = Net::DNS::RR.new("foo.example.com. 86400 A 10.1.2.3")
mx    = Net::DNS::RR.new("example.com. 7200 MX 10 mailhost.example.com.")
cname = Net::DNS::RR.new("www.example.com 300 IN CNAME www1.example.com")
txt   = Net::DNS::RR.new('baz.example.com 3600 HS TXT "text record"')

Incidentally, a, mx, cname and txt objects will be instances of respectively Net::DNS::RR::A, Net::DNS::RR::MX, Net::DNS::RR::CNAME and Net::DNS::RR::TXT classes.

The name and RR data are required; all other informations are optional. If omitted, the TTL defaults to 10800, type default to A and the RR class defaults to IN. Omitting the optional fields is useful for creating the empty RDATA sections required for certain dynamic update operations. All names must be fully qualified. The trailing dot (.) is optional.

The preferred method is however passing an hash with keys and values:

rr = Net::DNS::RR.new(
              :name    => "foo.example.com",
              :ttl     => 86400,
              :cls     => "IN",
              :type    => "A",
              :address => "10.1.2.3"
      )

rr = Net::DNS::RR.new(
              :name => "foo.example.com",
              :rdata => "10.1.2.3"
      )

Name and data are required; all the others fields are optionals like we've seen before. The data field can be specified either with the right name of the resource (:address in the example above) or with the generic key :rdata. Consult documentation to find the exact name for the resource in each subclass.

# File lib/net/dns/rr.rb, line 128
def initialize(arg)
  instance = case arg
    when String
      new_from_string(arg)
    when Hash
      new_from_hash(arg)
    else
      raise ArgumentError, "Invalid argument, must be a RR string or an hash of values"
  end

  if @type.to_s == "ANY"
    @cls = Net::DNS::RR::Classes.new("IN")
  end

  build_pack
  set_type

  instance
end

Return a new RR object of the correct type (like Net::DNS::RR::A if the type is A) from a binary string, usually obtained from network stream.

This method is used when parsing a binary packet by the Packet class.

# File lib/net/dns/rr.rb, line 155
def RR.parse(data)
  o = allocate
  obj,offset = o.send(:new_from_binary, data, 0)
  return obj
end

Same as RR.parse, but takes an entire packet binary data to perform name expansion. Default when analizing a packet just received from a network stream.

Return an instance of appropriate class and the offset pointing at the end of the data parsed.

# File lib/net/dns/rr.rb, line 168
def RR.parse_packet(data,offset)
  o = allocate
  o.send(:new_from_binary,data,offset)
end

Class accessor

# File lib/net/dns/rr.rb, line 244
def cls
  @cls.to_s
end

Return the RR object in binary data format, suitable for using in network streams, with names compressed. Must pass as arguments the offset inside the packet and an hash of compressed names.

This method is to be used in other classes and is not intended for user space programs.

TO FIX in one of the future releases

# File lib/net/dns/rr.rb, line 183
def comp_data(offset,compnames)
  type,cls = @type.to_i, @cls.to_i
  str,offset,names = dn_comp(@name,offset,compnames)
  str += [type,cls,@ttl,@rdlength].pack("n2 N n")
  offset += Net::DNS::RRFIXEDSZ
  return str,offset,names
end

Return the RR object in binary data format, suitable for using in network streams.

raw_data = rr.data
puts "RR is #{raw_data.size} bytes long"

# File lib/net/dns/rr.rb, line 197
def data
  type,cls = @type.to_i, @cls.to_i
  str = pack_name(@name)
  return str + [type,cls,@ttl,@rdlength].pack("n2 N n") + get_data
end

Canonical inspect method.

mx = Net::DNS::RR.new("example.com. 7200 MX 10 mailhost.example.com.")
#=> example.com.            7200    IN      MX      10 mailhost.example.com.

# File lib/net/dns/rr.rb, line 208
def inspect
  data = get_inspect 
  # Returns the preformatted string
  if @name.size < 24
    [@name, @ttl.to_s, @cls.to_s, @type.to_s, data].pack("A24 A8 A8 A8 A*")
  else
    to_a.join("   ")
  end
end

Returns an array with all the fields for the RR record.

mx = Net::DNS::RR.new("example.com. 7200 MX 10 mailhost.example.com.")
mx.to_a
#=> ["example.com.",7200,"IN","MX","10 mailhost.example.com."]

# File lib/net/dns/rr.rb, line 234
def to_a
  [@name, @ttl, @cls.to_s, @type.to_s, get_inspect]
end

Returns the RR in a string format.

mx = Net::DNS::RR.new("example.com. 7200 MX 10 mailhost.example.com.")
mx.to_s
#=> "example.com.            7200    IN      MX      10 mailhost.example.com."

# File lib/net/dns/rr.rb, line 224
def to_s
  inspect.to_s
end

Type accessor

# File lib/net/dns/rr.rb, line 239
def type
  @type.to_s
end