| Log Message:
| Fix a rather annoying problem where the sockaddr_dl which holds
| the link level name for the interface (ifp->if_sadl) is allocated
| before ifp->if_addrlen is initialized, which could lead to allocating
| too little space for the link level address.
| 
| Do this by splitting allocation of the link level name out of
| if_attach() and into if_alloc_sadl(), which is normally called
| by functions like ether_ifattach().  Network interfaces which
| don't have a link-specific attach routine must call if_alloc_sadl()
| themselves (example: gif).

This seems like an excellent time to document this interface
in section 9. Would you care to draft such a thing?

--jhawk
  (who is not terribly averse to doing the work for this, but thinks you
   might be better qualified.)