On Mon, Mar 25, 2019 at 5:36 AM Alan Maguire alan.maguire@oracle.com wrote:
test_tc_tunnel.sh sets up a pair of namespaces connected by a veth pair to verify encap/decap using bpf_skb_adjust_room. In testing this, it uses tunnel links as the peer of the bpf-based encap/decap. However because the same IP header is used for inner and outer IP, when packets arrive at the tunnel interface they will be dropped by reverse path filtering as those packets are expected on the veth interface (where the destination IP of the decapped packet is configured).
To avoid this, ensure reverse path filtering is disabled for the namespace using tunneling.
Fixes: 98cdabcd0798 ("selftests/bpf: bpf tunnel encap test") Signed-off-by: Alan Maguire alan.maguire@oracle.com
Acked-by: Willem de Bruijn willemb@google.com
Thanks, Alan. Indeed, I had been developing on a platform with reverse path filter off by default (debian stretch).