ipv6: don't use inetpeer to store metrics for routes.

Current IPv6 implementation uses inetpeer to store metrics for
routes. The problem of inetpeer is that it doesn't take subnet
prefix length in to consideration. If two routes have the same
address but different prefix length, they share same inetpeer.
So changing metrics of one route also affects the other. The
fix is to allocate separate metrics storage for each route.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9e69eb0..1250f90 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -104,6 +104,9 @@
 	struct inet_peer *peer;
 	u32 *p = NULL;
 
+	if (!(rt->dst.flags & DST_HOST))
+		return NULL;
+
 	if (!rt->rt6i_peer)
 		rt6_bind_peer(rt, 1);
 
@@ -252,6 +255,9 @@
 	struct inet6_dev *idev = rt->rt6i_idev;
 	struct inet_peer *peer = rt->rt6i_peer;
 
+	if (!(rt->dst.flags & DST_HOST))
+		dst_destroy_metrics_generic(dst);
+
 	if (idev != NULL) {
 		rt->rt6i_idev = NULL;
 		in6_dev_put(idev);
@@ -723,9 +729,7 @@
 			ipv6_addr_copy(&rt->rt6i_gateway, daddr);
 		}
 
-		rt->rt6i_dst.plen = 128;
 		rt->rt6i_flags |= RTF_CACHE;
-		rt->dst.flags |= DST_HOST;
 
 #ifdef CONFIG_IPV6_SUBTREES
 		if (rt->rt6i_src.plen && saddr) {
@@ -775,9 +779,7 @@
 	struct rt6_info *rt = ip6_rt_copy(ort, daddr);
 
 	if (rt) {
-		rt->rt6i_dst.plen = 128;
 		rt->rt6i_flags |= RTF_CACHE;
-		rt->dst.flags |= DST_HOST;
 		dst_set_neighbour(&rt->dst, neigh_clone(dst_get_neighbour_raw(&ort->dst)));
 	}
 	return rt;
@@ -1078,12 +1080,15 @@
 			neigh = NULL;
 	}
 
-	rt->rt6i_idev     = idev;
+	rt->dst.flags |= DST_HOST;
+	rt->dst.output  = ip6_output;
 	dst_set_neighbour(&rt->dst, neigh);
 	atomic_set(&rt->dst.__refcnt, 1);
-	ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);
-	rt->dst.output  = ip6_output;
+
+	ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
+	rt->rt6i_dst.plen = 128;
+	rt->rt6i_idev     = idev;
 
 	spin_lock_bh(&icmp6_dst_lock);
 	rt->dst.next = icmp6_dst_gc_list;
@@ -1261,6 +1266,14 @@
 	if (rt->rt6i_dst.plen == 128)
 	       rt->dst.flags |= DST_HOST;
 
+	if (!(rt->dst.flags & DST_HOST) && cfg->fc_mx) {
+		u32 *metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
+		if (!metrics) {
+			err = -ENOMEM;
+			goto out;
+		}
+		dst_init_metrics(&rt->dst, metrics, 0);
+	}
 #ifdef CONFIG_IPV6_SUBTREES
 	ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
 	rt->rt6i_src.plen = cfg->fc_src_len;
@@ -1607,9 +1620,6 @@
 	if (on_link)
 		nrt->rt6i_flags &= ~RTF_GATEWAY;
 
-	nrt->rt6i_dst.plen = 128;
-	nrt->dst.flags |= DST_HOST;
-
 	ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
 	dst_set_neighbour(&nrt->dst, neigh_clone(neigh));
 
@@ -1754,9 +1764,10 @@
 	if (rt) {
 		rt->dst.input = ort->dst.input;
 		rt->dst.output = ort->dst.output;
+		rt->dst.flags |= DST_HOST;
 
 		ipv6_addr_copy(&rt->rt6i_dst.addr, dest);
-		rt->rt6i_dst.plen = ort->rt6i_dst.plen;
+		rt->rt6i_dst.plen = 128;
 		dst_copy_metrics(&rt->dst, &ort->dst);
 		rt->dst.error = ort->dst.error;
 		rt->rt6i_idev = ort->rt6i_idev;