Re: [PATCH][RFC] etherip: Ethernet-in-IPv4 tunneling

[Thomas Graf <tgraf@suug.ch>]

* Lennert Buytenhek <20050112231615.GF14280@xi.wantstofly.org> 2005-01-13 00:16
> On Wed, Jan 12, 2005 at 03:11:40PM -0800, Ben Greear wrote:
> 
> > >>Also, could you add an ioctl that allowed one to query whether or not
> > >>a particular device is an etherip device?  I had always wished I had added
> > >>this earlier to the VLAN code :)
> > >
> > >Hmmm.  Bridge devices don't have this either, do they?  Can you name
> > >an advantage of having this?
> > 
> > I got the request several times with regard to VLANs.  Lots of people
> > (and applications) will want to know the interface type for various
> > reasons.  If you don't give them a nice programatic thing like an
> > IOCTL to call, they will undoubtedly start making assumptions based
> > off of the device name...
> 
> Makes sense..
> 
> Unfortunately SIOCGETTUNNEL is (SIOCDEVPRIVATE + 3), otherwise we could
> just say something like "If an ARPHRD_ETHER device supports SIOCGETTUNNEL,
> it's an ether/ip tunnel."
> 
> Any better ideas?  I hate adding more ioctls.

I think it should go into ip_tunnel_param, unforunately there are no
unused fields. Maybe schedule this for 2.7 together with a clean up
of all the tunnels so they share redundant code? Lots of gre related
code and comments spread over non-gre tunnels that should go away.