added strict validity for address families of SIOCxIFADDR_IN6 ioctls in order to prevent the kernel from installing unexpected ifaddr.
added strict validity for address families of SIOCxIFADDR_IN6 ioctls
in order to prevent the kernel from installing unexpected ifaddr.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame