Re: [PATCH net v4 2/4] net: gso: count the inner UDP header of encapsulated UDP GSO packets

[Eric Dumazet]

Le mar. 3 nov. 2026 à 13:44, Simon Horman <horms@xxxxxxxxxx> a écrit :
>
> On Sun, Nov 01, 2026 at 05:42:30PM +0100, Julius Bairaktaris wrote:
> > skb_gso_transport_seglen() adds the inner TCP header length for an
> > encapsulated GSO packet, but not the inner UDP header for
> > SKB_GSO_UDP_L4, whose gso_size covers the payload only. Every segment
> > of a UDP GSO packet in a UDP tunnel, built by UDP GRO behind a tunnel
> > socket or sent with UDP_SEGMENT over VXLAN, is counted 8 bytes short.
> > ip_forward() and ip_finish_output_gso() then let DF segments that
> > exceed the MTU by up to 8 bytes leave unfragmented.
> >
> > Add the inner UDP header as the unencapsulated branch does.
> >
> > Fixes: ee80d1ebe5ba ("udp: add udp gso")
> > Signed-off-by: Julius Bairaktaris <julius@xxxxxxxxxxxxxx>
>
> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>