Re: [PATCH v3 net-next v3 2/6] net: add support for segmenting TCP fraglist GSO packets

[Felix Fietkau]

On 26.04.24 09:44, Eric Dumazet wrote:
> On Fri, Apr 26, 2024 at 8:51 AM Felix Fietkau <nbd@xxxxxxxx> wrote:
> > Preparation for adding TCP fraglist GRO support. It expects packets to be
> > combined in a similar way as UDP fraglist GSO packets.
> > For IPv4 packets, NAT is handled in the same way as UDP fraglist GSO.
> >
> > Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> > ---
> >  net/ipv4/tcp_offload.c   | 65 ++++++++++++++++++++++++++++++++++++++++
> >  net/ipv6/tcpv6_offload.c |  3 ++
> >  2 files changed, 68 insertions(+)
> >
> > diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
> > index fab0973f995b..c493e95e09a5 100644
> > --- a/net/ipv4/tcp_offload.c
> > +++ b/net/ipv4/tcp_offload.c
> > @@ -28,6 +28,68 @@ static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq,
> >         }
> >  }
> >
> > +static void __tcpv4_gso_segment_csum(struct sk_buff *seg,
> > +                                    __be32 *oldip, __be32 *newip,
> > +                                    __be16 *oldport, __be16 *newport)
>
>
> Do we really need pointers for newip and newport ?
>
> > +{
> > +       struct tcphdr *th;
> > +       struct iphdr *iph;
> > +
> > +       if (*oldip == *newip && *oldport == *newport)
> > +               return;
> > +
> > +       th = tcp_hdr(seg);
> > +       iph = ip_hdr(seg);
> > +
> > +       inet_proto_csum_replace4(&th->check, seg, *oldip, *newip, true);
> > +       inet_proto_csum_replace2(&th->check, seg, *oldport, *newport, false);
> > +       *oldport = *newport;
> > +
> > +       csum_replace4(&iph->check, *oldip, *newip);
> > +       *oldip = *newip;
> > +}
> > +
> > +static struct sk_buff *__tcpv4_gso_segment_list_csum(struct sk_buff *segs)
> > +{
> > +       struct sk_buff *seg;
> > +       struct tcphdr *th, *th2;
> > +       struct iphdr *iph, *iph2;
>
> I would probably add a const qualifier to th and iph

Will do, thanks.

- Felix