+struct ifaddr *
+ifa_ifwithroute(flags, dst, gateway)
+int flags;
+struct sockaddr *dst, *gateway;
+{
+ struct ifaddr *ifa;
+ if ((flags & RTF_GATEWAY) == 0) {
+ /*
+ * If we are adding a route to an interface,
+ * and the interface is a pt to pt link
+ * we should search for the destination
+ * as our clue to the interface. Otherwise
+ * we can use the local address.
+ */
+ ifa = 0;
+ if (flags & RTF_HOST)
+ ifa = ifa_ifwithdstaddr(dst);
+ if (ifa == 0)
+ ifa = ifa_ifwithaddr(gateway);
+ } else {
+ /*
+ * If we are adding a route to a remote net
+ * or host, the gateway may still be on the
+ * other end of a pt to pt link.
+ */
+ ifa = ifa_ifwithdstaddr(gateway);
+ }
+ if (ifa == 0)
+ ifa = ifa_ifwithnet(gateway);
+ return (ifa);
+}
+
+#define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
+