Re: [PATCH net-next v4 4/4] net: gro: move L3 flush checks to tcp_gro_receive

[Willem de Bruijn]

Richard Gobert wrote:
> Willem de Bruijn wrote:
> > In v3 we discussed how the flush on network layer differences (like
> > TTL or ToS) currently only affect the TCP GRO path, but should apply
> > more broadly.
> > 
> > We agreed that it is fine to leave that to a separate patch series.
> > 
> > But seeing this patch, it introduces a lot of churn, but also makes
> > it harder to address that issue for UDP, as it now moves network
> > layer checks directly to the TCP code.
> Currently the logic of flush_id is scattered in tcp_gro_receive and
> {inet,ipv6}_gro_receive with conditionals rewriting ->flush and ->flush_id,
> so IMO the code should be more concise when it's in one place - in addition
> to not doing checks against non relevant packets.
> 
> With this patch, the fix will probably be simple, most likely just calling
> gro_network_flush from skb_gro_receive or from the relevant flow in
> udp_gro_receive_segment. Since this bug fix should be simple and it being
> not relevant to the optimization, I'd like to solve it in another series
> and properly test that new flow. Do you agree?

My main concern is moving this code to tcp_offload.c, if it likely
soon will be moved elsewhere again.