in_broadcast
if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
int in_broadcast(struct in_addr, struct ifnet *);
if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
isbroadcast = in_broadcast(dst->sin_addr, ifp);
isbroadcast = in_broadcast(dst->sin_addr, ifp);
in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {