nvlist_next
nvlist_next(ptr) - ptr, &nv);
nvlist_next(ptr) - ptr, &nvlist[i]);
ptr = nvlist_next(ptr);
while ((name = nvlist_next(parent, &type, &cookie)) != NULL) {
while ((name = nvlist_next(ports_nvl, &type, &cookie)) !=
while ((name = nvlist_next(slots_nvl, &type, &cookie)) != NULL) {