ifaof_ifpforaddr
struct ifaddr *ifaof_ifpforaddr(const struct sockaddr *, struct ifnet *);
ifa = ifaof_ifpforaddr(dst, ifp);
ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
info->rti_ifa = ifaof_ifpforaddr(sa, ifp);
ifa = ifaof_ifpforaddr(&sa, ifp);
ifa = ifaof_ifpforaddr(&sa, &sc->sc_if);
ifa = ifaof_ifpforaddr(&sa, ifp);
ifa = ifaof_ifpforaddr(&sa, &sc->sc_if);
ia = ifatoia(ifaof_ifpforaddr(sintosa(&sin), ifp));
ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
ifa = ifaof_ifpforaddr(sin6tosa(&sin6), ifp);