destination.
(Currently lack of their specification does not lead to any problem, because
kernel does not check the consistency between actual address and its
address family / length on raw socket.
However kernel should always check their consistency and stop sending packets
if there is a contradiction. Considering backward compatibility of
programs, I just fixed rtsol now; I'd like to fix the kernel behavior later.)
Reviewed by: ume
MFC after: 3 days