linux-kernel - Re: [PATCH] net: fix bridge multicast packet checksum validation

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Message-ID: <20160218173825.3dca8d27@xeon-e3>
Date:	Thu, 18 Feb 2016 17:38:25 -0800
From:	Stephen Hemminger <stephen@...workplumber.org>
To:	David Miller <davem@...emloft.net>
Cc:	linus.luessing@...3.blue, netdev@...r.kernel.org,
	bridge@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
	sgunderson@...foot.com, noltari@...il.com, tom@...bertland.com
Subject: Re: [PATCH] net: fix bridge multicast packet checksum validation

On Thu, 18 Feb 2016 15:35:42 -0500 (EST)
David Miller <davem@...emloft.net> wrote:

> From: Linus Lüssing <linus.luessing@...3.blue>
> Date: Mon, 15 Feb 2016 03:07:06 +0100
> 
> > @@ -4084,10 +4089,22 @@ struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
> >  	if (!pskb_may_pull(skb_chk, offset))
> >  		goto err;
> >  
> > -	__skb_pull(skb_chk, offset);
> > +	ip_summed = skb->ip_summed;
> > +	csum_valid = skb->csum_valid;
> > +	csum_level = skb->csum_level;
> > +	csum_bad = skb->csum_bad;
> > +	csum = skb->csum;
> > +
> > +	skb_pull_rcsum(skb_chk, offset);
> >  	ret = skb_chkf(skb_chk);
> >  	__skb_push(skb_chk, offset);
> >  
> > +	skb->ip_summed = ip_summed;
> > +	skb->csum_valid = csum_valid;
> > +	skb->csum_level = csum_level;
> > +	skb->csum_bad = csum_bad;
> > +	skb->csum = csum;
> > +
> 
> There really has to be a better way to fix this :-/

Agreed, this is gross.