Re: [PATCH net-next v2] selftests/net/openvswitch: add flow modify test

[Aaron Conole <aconole@redhat.com>]

Minxi Hou <houminxi@gmail.com> writes:

> Add mod_flow() and the mod-flow CLI command to ovs-dpctl.py, exercising
> OVS_FLOW_CMD_SET. Add test_flow_set which first modifies an existing
> flow with new actions and verifies the change via traffic, then modifies
> the same flow without actions and verifies the kernel handles the
> no-actions case gracefully.
>
> The no-actions path is unreachable from userspace OVS tools (dpctl
> mod-flow requires actions) but reachable via raw netlink. This is the
> code path where Adrian Moreno found a possible kfree_skb of ERR_PTR
> when reply allocation fails after locking.
>
> Make parse() skip OVS_FLOW_ATTR_ACTIONS when actstr is None so the
> kernel enters the post-lock allocation branch in ovs_flow_cmd_set().
> After the no-actions set, verify via dump-flows that the flow retained
> its drop action.
>
> Suggested-by: Aaron Conole <aconole@redhat.com>
> Signed-off-by: Minxi Hou <houminxi@gmail.com>
> ---

Reviewed-by: Aaron Conole <aconole@redhat.com>