Subject: Re: PATCH: fix bridged 802.3ad bonding

From: Stephen Hemminger <[email-masked]>
Date: Wed, 4 Jun 2008 09:06:33 -0700

On Wed, 4 Jun 2008 10:24:25 +0200
Jiri Bohac <[email-masked]> wrote:

> On Tue, Jun 03, 2008 at 09:55:19PM -0700, Stephen Hemminger wrote:
> > I prefer the following because it process all link-local frames through
> > the normal input path. This means the frames will:
> > 	* be filterable by netfilter
> 
> Well, the LACP frames are not filtered by netfilter when there is
> bonding on its own (not part of a bridge), so I don't see why
> this should change when the bond is made part of a bridge.
> 
> Maybe it is a good idea to run the LACP frames through netfilter,
> but I think this should be done consistently in the bonding code,
> whether or not bridging is set up, and probably on the individual
> slave interfaces. It does not make sense to filter bonding's LACP
> frames in ebtables, IMHO.
> 
> > 	* not forwarded across bridge (this is important).
> 
> I thought this was the case with my second patch as well (?)
> 
>  
> > --- a/net/bridge/br_input.c	2008-06-03 21:44:54.000000000 -0700
> > +++ b/net/bridge/br_input.c	2008-06-03 21:52:20.000000000 -0700
> > @@ -135,15 +135,12 @@ struct sk_buff *br_handle_frame(struct n
> >  		/* Pause frames shouldn't be passed up by driver anyway */
> >  		if (skb->protocol == htons(ETH_P_PAUSE))
> >  			goto drop;
> > -
> > -		/* Process STP BPDU's through normal netif_receive_skb() path */
> > -		if (p->br->stp_enabled != BR_NO_STP) {
> > -			if (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
> > -				    NULL, br_handle_local_finish))
> > -				return NULL;
> > -			else
> > -				return skb;
> > -		}
> > +
> > +		if (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
> > +			    NULL, br_handle_local_finish))
> > +			return NULL;	/* frame consumed by filter */
> > +		else
> > +			return skb;	/* continue processing */
> >  	}
> >  
> >  	switch (p->state) {
> 
> where did the "if (p->br->stp_enabled != BR_NO_STP)" condition
> go? Is it not needed? I thought it was there to prevent the STP
> BPDUs from being handled when STP is turned off.
> 

That is already done in br_stp_rcv so the check here was not
needed.