[IPV6] take rt6i_idev into account when looking up routes.

This is required because we will add "same" routes 
(except for rt6i_idev) on loopback for routes for local address.
Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>

net/ipv6/ip6_fib.c

@@ -449,9 +449,10 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 			 *	Same priority level
 			 */
 
-			if ((iter->rt6i_dev == rt->rt6i_dev) &&
-			    (ipv6_addr_cmp(&iter->rt6i_gateway,
-					   &rt->rt6i_gateway) == 0)) {
+			if (iter->rt6i_dev == rt->rt6i_dev &&
+			    iter->rt6i_idev == rt->rt6i_idev &&
+			    ipv6_addr_cmp(&iter->rt6i_gateway,
+					   &rt->rt6i_gateway) == 0) {
 				if (!(iter->rt6i_flags&RTF_EXPIRES))
 					return -EEXIST;
 				iter->rt6i_expires = rt->rt6i_expires;

net/ipv6/route.c

@@ -183,9 +183,17 @@ static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt,
 			struct net_device *dev = sprt->rt6i_dev;
 			if (dev->ifindex == oif)
 				return sprt;
-			if (dev->flags&IFF_LOOPBACK)
+			if (dev->flags & IFF_LOOPBACK) {
+				if (sprt->rt6i_idev->dev->ifindex != oif) {
+					if (strict && oif)
+						continue;
+					if (local && (!oif || 
+						      local->rt6i_idev->dev->ifindex == oif))
+						continue;
+				}
 				local = sprt;
 			}
+		}
 
 		if (local)
 			return local;