Darren Reed <darrenr@reed.wattle.id.au> writes:

> In some email I received from Christian E. Hopps, sie wrote:
> [...]
> >         sdl_index/sdl_nlen+sdl_data
> >                         -- specifies which interface to receive frame
> >                         from.  If no interface is specified then every
> >                         interface is eligible.
> >         
> >         sdl_type        -- if no interface is chosen the user
> >                         can select a specific interface type,
> >                         e.g., IFT_ETHER.
> > 
> >         sdl_slen+sdl_data
> >                         -- specifies a selector in the logical frame.
> >                         e.g. for FRAMETYPE_E2 it would be a 2 octet
> >                         value specifying the ethertype, and for
> >                         FRAMETYPE_LLC it would be the destination
> >                         service access point (i.e., llc_dsap).
> [...]
> 
> sdl_data is used twice here...are these three therefore mutually exclusive
> options ?  I think it would be useful to be able to specify a combination
> of these things.

No they aren't mutually exclusive.  I'm not defining new semantics for
sockaddr_dl, merely using them.

The layout of sockaddr_dl is that sdl_data is sdl_nlen bytes of name,
followed by sdl_alen bytes of address followed by sdl_slen bytes of
selector (e.g., see the LLADDR() currently in the if_dl.h).

So yes you can specify both type and selector or index and selector or
name and selector.

Chris.