On Thu, Feb 07, 2019 at 02:54:16PM -0500, Willem de Bruijn wrote:
> From: Willem de Bruijn <will...@google.com>
>
> bpf_skb_change_proto and bpf_skb_adjust_room change skb header length.
> For GSO packets they adjust gso_size to maintain the same MTU.
>
> The gso size can only be safely adjusted on bytestream protocols.
> Commit d02f51cbcf12 ("bpf: fix bpf_skb_adjust_net/bpf_skb_proto_xlat
> to deal with gso sctp skbs") excluded SKB_GSO_SCTP.
>
> Since then type SKB_GSO_UDP_L4 has been added, whose contents are one
> gso_size unit per datagram. Also exclude these.
>
> Move from a blacklist to a whitelist check to future proof against
> additional such new GSO types, e.g., for fraglist based GRO.
>
> Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT")
> Signed-off-by: Willem de Bruijn <will...@google.com>
Applied to bpf tree.
I agree that whitelist approach is the most appropriate.
