Small patch to multicast code...

[John Hay]

On Mon, Aug 25, 2008 at 09:02:07PM +0200, John Hay wrote:
> On Fri, Aug 22, 2008 at 03:03:30PM -0700, gnn at FreeBSD.org wrote:
> > At Fri, 22 Aug 2008 22:43:39 +0100,
> > Bruce M. Simpson wrote:
> > > 
> > > gnn at FreeBSD.org wrote:
> > > > Somehow the data that the device needs to do the proper checksum
> > > > offload is getting trashed here.  Now, since it's clear we need a
> > > > writable packet structure so that we don't trash the original, I'm
> > > > wondering if the m_pullup() will be sufficient.
> > > >   
> > > 
> > > If it's serious enough to break UDP checksumming on the wire, perhaps we 
> > > should just swallow the mbuf allocator heap churn and do the m_dup() for 
> > > now, but slap in a big comment about why it's there.
> > 
> > I think if none of us finds a better way before early next week that's
> > what I'll do so that this at least works in 7.1.
> 
> I think we and others have been hitting this problem:
> 
> kern/119635: [em] Bad UDP packet checksum with em(4) and rxcsum/txcsum enabled
> http://www.freebsd.org/cgi/query-pr.cgi?pr=119635
> 
> I'll try out your patch.

I have tried it and it does fix my problem. RIP2 over multicast works
again. :-)

John
-- 
John Hay -- John.Hay at meraka.csir.co.za / jhay at FreeBSD.org