Ethernet NIC drivers depending unconditionally on INET

[Pyun YongHyeon]

On Sat, Jun 13, 2009 at 09:15:06AM +0200, Michael Tuexen wrote:
> On Jun 13, 2009, at 2:48 AM, Andrew Gallatin wrote:
> 
> >Michael Tuexen wrote:
> >
> >> I'm not sure if we need additional IFCAP_RXCSUM6 IFCAP_TXCSUM6
> >> capabilities... Why would we want to enable IPv4 offloading and
> >> not IPv6 or vice versa?
> >
> >I'd assume that some older hardware supports IPv4 offloads, but
> >might not have support for IPv6 offloads.
> Sure. But then the driver only provides the CSUM_ flags which
> are appropriate. For example, a similar thing is already in the
> igb driver:
> 
>  1167       if (ifp->if_capenable & IFCAP_TXCSUM) {
>  1168                 ifp->if_hwassist |= (CSUM_TCP | CSUM_UDP);
>  1169 #if __FreeBSD_version >= 800000
>  1170                 if (adapter->hw.mac.type == e1000_82576)
>  1171                         ifp->if_hwassist |= CSUM_SCTP;
>  1172 #endif
>  1173         }

That would disable all IPv4/IPv6 checksum offloading if
administrator disable IFCAP_TXCSUM. If we have IFCAP_TXCSUM6/
IFCAP_RXCSUM6 users could choose best working one even if some part
of driver/controller had checksum offload bugs.

> 
> For FreeBSD 8 and a particular chip, SCTP checksum offloading
> is supported. No need for a special IFCAP_TXCSUM.
> 
> Best regards
> Michael
> 
> >
> >Drew
>