npf_conn_conkey
if (!npf_conn_conkey(npc, &key, di, NPF_FLOW_FORW)) {
if (!npf_conn_conkey(npc, fw, di, NPF_FLOW_FORW) ||
!npf_conn_conkey(npc, bk, di ^ PFIL_ALL, NPF_FLOW_BACK)) {
unsigned npf_conn_conkey(const npf_cache_t *, npf_connkey_t *,