- values containing exactly six octets are treated as type 3 (DUID-LL)
- values containing seven and more octets get the length tag added in native endianess
- all other values are treated as invalid
git-svn-id: svn://svn.openwrt.org/openwrt/packages@28079 3c298f89-4303-0410-b956-a3cf2f4a3e73