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Date: Thu, 25 Apr 2024 09:56:50 -0400
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Richard Gobert <richardbgobert@gmail.com>, 
 Willem de Bruijn <willemdebruijn.kernel@gmail.com>, 
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Subject: Re: [PATCH net v3 1/2] net: gro: fix udp bad offset in socket lookup
 by adding {inner_}network_offset to napi_gro_cb
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> >> --- a/net/ipv6/tcpv6_offload.c
> >> +++ b/net/ipv6/tcpv6_offload.c
> >> @@ -29,7 +29,8 @@ struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
> >>  
> >>  INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
> >>  {
> >> -	const struct ipv6hdr *iph = ipv6_hdr(skb);
> >> +	const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
> >> +	const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
> >>  	struct tcphdr *th = tcp_hdr(skb);
> >>  
> > 
> > Only udp code is affected, as only that can be used as tunnel.
> > 
> > For bug fixes, let's try to avoid touching other code. Also that vlan.
> > 
> > As a minimal patch all that is needed is the following, right?
> > 
> > - add the fields
> > - store in inet_gro_receive + ipv6_gro_receive
> > - read in udp[46]_gro_complete and udp[46]_lib_lookup_skb
> > 
> 
> This approach is smaller, thanks for writing it down.
> 
> What do you think about doing this and still writing to
> inner_network_offset exclusively in {inet,ipv6}_gro_receive? I still
> prefer it for reasons discussed in the previous series. The code line
> in vlan_gro_receive will still be there, but that will be the only
> addition to your snippet.

That sounds fine, thanks.