On 3/4/19 5:27 PM, Peter Oskolkov wrote:
> GSO needs inner headers and inner protocol set properly to work.
>
> skb->inner_mac_header: skb_reset_inner_headers() assigns the current
> mac header value to inner_mac_header; but it is not set at the point,
> so we need to call skb_reset_inner_mac_header, otherwise gre_gso_segment
> fails: it does
>
> int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
> ...
> if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
> ...
>
> skb->inner_protocol should also be correctly set.
>
> Fixes: ca78801a81e0 ("bpf: handle GSO in bpf_lwt_push_encap")
> Signed-off-by: Peter Oskolkov <p...@google.com>
> ---
> net/core/lwt_bpf.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
> index cf2f8897ca19..126d31ff5ee3 100644
> --- a/net/core/lwt_bpf.c
> +++ b/net/core/lwt_bpf.c
> @@ -625,6 +625,8 @@ int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr,
> u32 len, bool ingress)
>
> /* push the encap headers and fix pointers */
> skb_reset_inner_headers(skb);
> + skb_reset_inner_mac_header(skb); /* mac header is not yet set */
> + skb_set_inner_protocol(skb, skb->protocol);
right, I should have remember that from an mpls change (48d2ab609b6bb).
Reviewed-by: David Ahern <dsah...@gmail.com>
