OVS_PACKET_ATTR_KEY
err = ovs_nla_put_key(key, key, OVS_PACKET_ATTR_KEY, false, user_skb);
if (!a[OVS_PACKET_ATTR_PACKET] || !a[OVS_PACKET_ATTR_KEY] ||
err = ovs_flow_key_extract_userspace(net, a[OVS_PACKET_ATTR_KEY],
[OVS_PACKET_ATTR_KEY] = { .type = NLA_NESTED },