[IPV4]: Rework key route lookup interface slightly.

include/net/route.h

@@ -112,7 +112,8 @@ extern void		ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
 				       u32 src, u8 tos, struct net_device *dev);
 extern void		ip_rt_advice(struct rtable **rp, int advice);
 extern void		rt_cache_flush(int how);
-extern int		ip_route_output_key(struct rtable **, const struct flowi *flp);
+extern int		__ip_route_output_key(struct rtable **, const struct flowi *flp);
+extern int		ip_route_output_key(struct rtable **, struct flowi *flp);
 extern int		ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
 extern unsigned short	ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
 extern void		ip_rt_send_redirect(struct sk_buff *skb);
@@ -150,13 +151,15 @@ static inline int ip_route_connect(struct rtable **rp, u32 dst, u32 src, u32 tos
 					 .dport = dport } } };
 
 	int err;
-	err = ip_route_output_key(rp, &fl);
-	if (err || (dst && src))
+	if (!dst || !src) {
+		err = __ip_route_output_key(rp, &fl);
+		if (err)
 			return err;
 		fl.fl4_dst = (*rp)->rt_dst;
 		fl.fl4_src = (*rp)->rt_src;
 		ip_rt_put(*rp);
 		*rp = NULL;
+	}
 	return ip_route_output_key(rp, &fl);
 }
 

net/ipv4/route.c

@@ -1993,7 +1993,7 @@ out:	return err;
 	goto done;
 }
 
-int ip_route_output_key(struct rtable **rp, const struct flowi *flp)
+int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
 {
 	unsigned hash;
 	struct rtable *rth;
@@ -2025,6 +2025,19 @@ int ip_route_output_key(struct rtable **rp, const struct flowi *flp)
 	return ip_route_output_slow(rp, flp);
 }
 
+int ip_route_output_key(struct rtable **rp, struct flowi *flp)
+{
+	int err;
+
+	if ((err = __ip_route_output_key(rp, flp)) != 0)
+		return err;
+#if 0
+	return flp->proto ? xfrm_lookup((struct dst_entry**)rp, flp, NULL, 0) : 0;
+#else
+	return 0;
+#endif
+}
+
 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 			int nowait)
 {