rn_search
struct radix_node *t = rn_search(v_arg, top);
x = rn_search(addmask_key, rn_masktop);
tt = rn_search(v, x);
struct radix_node *t = rn_search(v_arg, top);
x = rn_search(addmask_key, maskhead->head.rnh_treetop);
*rn_search(const void *, struct radix_node *),
tt = rn_search(v, x);