From: Jiri Pirko <j...@resnulli.us> Date: Mon, 16 Oct 2017 16:26:34 +0200
> From: Jiri Pirko <j...@mellanox.com> > > Petr says: > > The current code doesn't offload GRE decapsulation unless there's a > corresponding encapsulation route as well. While not strictly incorrect (when > encap route is absent, the decap route traps traffic to CPU and the kernel > handles it), it's a missed optimization opportunity. > > With this patchset, IPIP entries are created as soon as offloadable tunneling > netdevice is created. This then leads to offloading of decap route, if one > exists, or is added afterwards, even when no encap route is present. > > In Linux, when there is a decap route, matching IP-in-IP packets are always > decapsulated. However, with IPv4 overlays in particular, whether the inner > packet is then forwarded depends on setting of net.ipv4.conf.*.rp_filter. When > RP filtering is turned on, inner packets aren't forwarded unless there's a > matching encap route. The mlxsw driver doesn't reflect this behavior in other > router interfaces, and thus it's not implemented for tunnel types either. A > better support for this will be subject of follow-up work. Series applied.
