Ethernet (Raw)

[Joel Sherrill]

"Smith, Gene" wrote:
> 
> > >  > If not, then can the tap design/interface be used as a model to
> > >  > provide the write side?
> > >
> > > I don't know to both questions.  if_tap operates at the very bottom
> > > layer of the ip stack, just after the driver submits the ethernet
> > > frame to it.  The sending side looks fairly involved with a
> > > per-interface send queue.  I would be suprised if there
> > wasn't a hook
> > > in there someplace.
> 
> So it looks like I can use the 'tap' thing to receive frames via its
> callback function but sending eth frames may or may not contain a hook?
> 
> > >  Do you know if SOCK_RAW is supported by the
> > > stack?
> 
> I don't think raw sockets are what I am looking for since I need to send eth
> frames based on destination mac address and don't want any ip header stuff
> in front. (But you may already know this.)

This reference makes me think that SOCK_RAW might work for you.

http://www.sunmanagers.org/archives/1991/0162.html

It points to an example which may or may not be current.  I found a 
Linux page which said that ping responses are generated by a user land
program using SOCK_RAW so you might be able to get by.

> -gene

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