ifa_ifwithaddr
rc = (ifa_ifwithaddr(addr) != NULL);
struct ifaddr *ifa_ifwithaddr(const struct sockaddr *);
ifa = ifa_ifwithaddr((struct sockaddr *)&in4);
ifa = ifa_ifwithaddr((struct sockaddr *)&in6);
ifa = ifa_ifwithaddr(gateway);
info->rti_ifa = ifa_ifwithaddr(ifaaddr);
ia = ifatoia(ifa_ifwithaddr(sintosa(&dst)));
ifa = ifa_ifwithaddr((struct sockaddr *) sin);
ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) != NULL) {
if ((ifa = ifa_ifwithaddr((const struct sockaddr *)&sin6)) ==
(ifa = ifa_ifwithaddr((struct sockaddr *)addr)) == NULL) {
ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
ifa = ifa_ifwithaddr((struct sockaddr *)&sin6);