Subject: Re: [PATCH] net: Add etun driver

From: Ben Greear <[email-masked]>
Date: Fri, 06 Apr 2007 20:31:51 -0700

Eric W. Biederman wrote:
> Ben Greear <[email-masked]> writes:
>
>   
>> Is there any way to tell for certain if an interface is a etun or not?  Maybe
>> a file could be found (or not) in sysfs somewhere?
>>     
>
> Link for any decent network driver ethtool -i <interface>
>   
I guess that will do, but then if you ever change the strings, any 
user-space that is
depending on this will break or have to be modified with additional 
cruft.  It seems
cleaner to me to have an ioctl or a specific place in /proc or some 
other virtual
fs, but I can deal with it either way...

>> Also, how do you find the peer device from user-space?  This would be very
>> useful
>> for anyone trying to manage these devices with a user-space program.
>>     
>
> Currently "ethtool -S <interface>"
> And read the partner_ifindex.
>   
Ok, that will work.  Again, my personal preference is for a single 
specific ioctl or proc'ish file
to read the specific value instead of having to parse strings, but this 
will do.

> Further whoever generates the pair specifies the initial set of names.
>   
Yeah, but you can't depend on knowing that in an interesting environment.

Thanks,
Ben

-- 
Ben Greear <[email-masked]> 
Candela Technologies Inc  http://www.candelatech.com