pf_find_src_node
extern struct pf_ksrc_node *pf_find_src_node(struct pf_addr *,
*sn = pf_find_src_node(src, r_track, af, sh, sn_type, true);
sn = pf_find_src_node(&pd->nsaddr, r,
sn = pf_find_src_node(saddr, r, saf, &sh, sn_type, false);