lkml.org 
[lkml]   [2007]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC] iw_cxgb3: Support "iwarp-only" interfaces to avoid 4-tuple conflicts with the host stack.


Steve Wise wrote:
>
>
> Roland Dreier wrote:
>> > > What's wrong with my suggestion of having the iwarp driver create an
>> > > "iwX" interface to go with the normal "ethX" interface? It seems
>> > > simpler to me, and there's a somewhat similar precedent with how
>> > > mac80211 devices create both wlan0 and wmaster0 interfaces.
>> > > - R.
>> > > It seemed much more painful for me to implement. :-)
>> > > I'll look into this, but I think for this to be done, the
>> changes must
>> > be in the cxgb3 driver, not the rdma driver, because the guts of the
>> > netdev struct are all private to cxgb3. Remember that this interface
>> > needs to still do non TCP traffic (like ARP and UDP)...
>> > > Maybe you have something in mind here that I'm not thinking about?
>>
>> No, I was just spouting off.
>>
>
> At least someone is looking at my patch. ;-)
>
>> But the whole "create a magic alias" seems kind of unfriendly to the
>> user. Maybe as you said, the cxgb3 net driver could create the alias
>> for the iw_cxgb3 driver?
>
> I agree that it is not very user friendly.
>
> My current patch just utilizes the IP address alias logic in the IP
> stack. So when you do 'ifconfig ethxx:blah ipaddr up' it creates a
> struct in_ifaddr which contains a ptr to the real struct net_device that
> services this alias. However, from what I can tell, I cannot just
> create one of these without binding an address. So the driver cannot
> create the alias interface until it knows the ipaddr/netmask/etc. IE:
> if you say 'ifconfig ethxx:blah up' it fails... You must supply an
> address to get one of these created.
>
> To have the cxgb3 driver create something like 'iw0', I think it would
> need to create a full net_device struct. This makes the change much
> more complex. But perhaps its the right thing to do...
>
> Steve.
>

Also, I could defer registering the device with the rdma core until the
alias interface is created by the user. Thus the T3 device wouldn't be
available for use until the ethxx:iw interface is created.

And I could log a WARN or INFO message if the iw_cxgb3 module is loaded
and no ethxx:iw alias exists. This would help clue in the user...

Steve.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-09-05 19:29    [W:1.244 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site