On 11/29/16 at 11:01pm, Alexei Starovoitov wrote:

On Wed, Nov 30, 2016 at 07:48:51AM +0100, Thomas Graf wrote:

quoted

Should we check in __bpf_redirect_common() whether mac_header <
nework_header then or add it to lwt-bpf conditional on
dev_is_mac_header_xmit()?

may be only extra 'if' in lwt-bpf is all we need?

Agreed, I will add a mac_header < network_header check to lwt-bpf if we
redirect to an l2 device.

I'm still missing what will happen if we 'forget' to do
bpf_skb_push() inside the lwt-bpf program, but still do redirect
in lwt_xmit stage to l2 netdev...

The same as for a AF_PACKET socket not providing an actual L2 header.
I will add a test case to cover this scenario as well.