Net::DNS::Names

# File lib/net/dns/names/names.rb, line 87
def dn_comp(name,offset,compnames)
  names = {}
  ptr = 0
  str = ""
  arr = names_array(name)
  arr.each do |entry|
    if compnames.has_key?(entry)
      ptr = 0xC000 | compnames[entry]
      str += [ptr].pack("n")
      offset += INT16SZ
      break
    else
      len = entry.unpack("C")[0]
      elem = entry[1..len]
      str += [len,elem].pack("Ca*")
      names.update({"#{entry}" => offset})
      offset += len
    end
  end
  return str,offset,names
end

# File lib/net/dns/names/names.rb, line 30
def dn_expand(packet,offset)
  name = ""
  packetlen = packet.size
  while true
    raise ExpandError, "Offset is greater than packet lenght!" if packetlen < (offset+1)
    len = packet.unpack("@#{offset} C")[0]
    
    if len == 0
      offset += 1
      break
    elsif (len & 0xC0) == 0xC0
      raise ExpandError, "Packet ended before offset expand" if packetlen < (offset+INT16SZ)
      ptr = packet.unpack("@#{offset} n")[0]
      ptr &= 0x3FFF
      name2 = dn_expand(packet,ptr)[0]
      raise ExpandError, "Packet is malformed!" if name2 == nil
      name += name2
      offset += INT16SZ
      break
    else
      offset += 1
      raise ExpandError, "No expansion found" if packetlen < (offset+len)
      elem = packet[offset..offset+len-1]
      name += "#{elem}."
      offset += len
    end
  end
  return [name,offset] # name.chomp(".") if trailing dot has to be omitted
end

# File lib/net/dns/names/names.rb, line 73
def names_array(name)
  arr = name.split(".")
  ar = []
  string = ""
  arr.size.times do |i|
    x = i+1
    elem = arr[-x]
    len = elem.size
    string = ((string.reverse)+([len,elem].pack("Ca*")).reverse).reverse
    ar.unshift(string)
  end
  return ar
end

# File lib/net/dns/names/names.rb, line 60
def pack_name(name)
  if name.size > 63
    raise ArgumentError, "Label data cannot exceed 63 chars"
  end
  arr = name.split(".")
  str = ""
  arr.each do |elem|
    str += [elem.size,elem].pack("Ca*")
  end
  str += [0].pack("C")
  str
end

# File lib/net/dns/names/names.rb, line 109
def valid?(name)
  if name =~ /^([a-z0-9]([-a-z0-9]*[a-z0-9])?\.)+((a[cdefgilmnoqrstuwxz]|aero|arpa)|(b[abdefghijmnorstvwyz]|biz)|(c[acdfghiklmnorsuvxyz]|cat|com|coop)|d[ejkmoz]|(e[ceghrstu]|edu)|f[ijkmor]|(g[abdefghilmnpqrstuwy]|gov)|h[kmnrtu]|(i[delmnoqrst]|info|int)|(j[emop]|jobs)|k[eghimnprwyz]|l[abcikrstuvy]|(m[acdghklmnopqrstuvwxyz]|mil|mobi|museum)|(n[acefgilopruz]|name|net)|(om|org)|(p[aefghklmnrstwy]|pro)|qa|r[eouw]|s[abcdeghijklmnortvyz]|(t[cdfghjklmnoprtvwz]|travel)|u[agkmsyz]|v[aceginu]|w[fs]|y[etu]|z[amw])$/
    return name
  else
    raise ArgumentError, "Invalid FQDN: #{name}"
  end
end