rt_lookup
if ((r = rt_lookup(DT_RTR, &addr)) == NULL)
if ((r = rt_lookup(DT_NET, &fw_addr)) == NULL ||
struct rt_node *rt_lookup(enum dst_type, struct in6_addr *);
nr = rt_lookup(DT_NET, rn->nexthop.s_addr);
struct rt_node *rt_lookup(enum dst_type, in_addr_t);
if ((r = rt_lookup(DT_RTR, htonl(v->adv_rtr))) == NULL)
(r = rt_lookup(DT_NET, v->lsa->data.asext.fw_addr)) == NULL)