NPF_NTAG_PASS
(void)nbuf_add_tag(nbuf, NPF_NTAG_PASS);
return nbuf_find_tag(nbuf, &ntag) == 0 && (ntag & NPF_NTAG_PASS) != 0;
(void)npf_mbuf_add_tag(npc->npc_nbuf, m, NPF_NTAG_PASS);
(void)nbuf_add_tag(npc->npc_nbuf, NPF_NTAG_PASS);