ovs_nla_get_ufid
ufid_present = ovs_nla_get_ufid(&sfid, a[OVS_FLOW_ATTR_UFID], log);
ufid_present = ovs_nla_get_ufid(&ufid, a[OVS_FLOW_ATTR_UFID], log);
ufid_present = ovs_nla_get_ufid(&ufid, a[OVS_FLOW_ATTR_UFID], log);
if (ovs_nla_get_ufid(sfid, ufid, log))
bool ovs_nla_get_ufid(struct sw_flow_id *, const struct nlattr *, bool log);