From: Patrick McHardy <[email protected]>
Date: Tue, 06 Nov 2007 01:21:09 +0100
> David Miller wrote:
> > From: Patrick McHardy <[email protected]>
> > Date: Mon, 05 Nov 2007 19:00:19 +0100
> >
> >> This looks like a rather expensive operation for the unlikely case
> >> that packets will be received by a packet socket. IMO it should only
> >> be reconstructed if actually needed, by af_packet itself.
> >
> > Completely agreed. We should not do this by default when %99
> > of the networking stack simply does not care about this.
>
>
> I think there is one more case that matters, which is briding
> from a device with VLAN stripping for a VLAN not configured
> locally. The tag will be stripped and will be lost for forwarded
> packets. But I'm not exactly sure this really can be configured
> (time for bed so I'll check tommorrow).
If so then when such rules are loaded, just like PF_PACKET, it can set
the indication to start reconstituting VLAN headers stripped by HW.
> >> As we discussed some time back storing the VLAN tag in the CB on
> >> TX clashes with other users of the CB like qdiscs, so we need a
> >> new field in the skb for this anyway.
> >
> > Someone will have to find a way to remove some other fields in
> > sk_buff before I'm going to allow more space to be eaten up
> > by this completely fringe case feature.
>
> We have a two byte hole after tc_verd where we could fit this in.
> But I'm pretty sure we also could reuse some other fields on input,
> like queue_mapping or maybe even destructor for unowned skbs.
Two bytes is enough, so if there is a hole we can use it.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
