1 files changed, 51 insertions, 28 deletions

diff --git a/net/core/dst.c b/net/core/dst.c
index 193af526e908..bc9c9be4e080 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -49,8 +49,7 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops,
 	      unsigned short flags)
 {
 	dst->dev = dev;
-	if (dev)
-		dev_hold(dev);
+	netdev_hold(dev, &dst->dev_tracker, GFP_ATOMIC);
 	dst->ops = ops;
 	dst_init_metrics(dst, dst_default_metrics.metrics, true);
 	dst->expires = 0UL;
@@ -81,11 +80,11 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
 {
 	struct dst_entry *dst;
 
-	if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
+	if (ops->gc &&
+	    !(flags & DST_NOCOUNT) &&
+	    dst_entries_get_fast(ops) > ops->gc_thresh) {
 		if (ops->gc(ops)) {
-			printk_ratelimited(KERN_NOTICE "Route cache is full: "
-					   "consider increasing sysctl "
-					   "net.ipv[4|6].route.max_size.\n");
+			pr_notice_ratelimited("Route cache is full: consider increasing sysctl net.ipv6.route.max_size.\n");
 			return NULL;
 		}
 	}
@@ -118,8 +117,7 @@ struct dst_entry *dst_destroy(struct dst_entry * dst)
 
 	if (dst->ops->destroy)
 		dst->ops->destroy(dst);
-	if (dst->dev)
-		dev_put(dst->dev);
+	netdev_put(dst->dev, &dst->dev_tracker);
 
 	lwtstate_put(dst->lwtstate);
 
@@ -144,7 +142,7 @@ static void dst_destroy_rcu(struct rcu_head *head)
 
 /* Operations to mark dst as DEAD and clean up the net device referenced
  * by dst:
- * 1. put the dst under loopback interface and discard all tx/rx packets
+ * 1. put the dst under blackhole interface and discard all tx/rx packets
  *    on this route.
  * 2. release the net_device
  * This function should be called when removing routes from the fib tree
@@ -161,8 +159,8 @@ void dst_dev_put(struct dst_entry *dst)
 	dst->input = dst_discard;
 	dst->output = dst_discard_out;
 	dst->dev = blackhole_netdev;
-	dev_hold(dst->dev);
-	dev_put(dev);
+	netdev_ref_replace(dev, blackhole_netdev, &dst->dev_tracker,
+			   GFP_ATOMIC);
 }
 EXPORT_SYMBOL(dst_dev_put);
 
@@ -237,37 +235,62 @@ void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
 }
 EXPORT_SYMBOL(__dst_destroy_metrics_generic);
 
-static struct dst_ops md_dst_ops = {
-	.family =		AF_UNSPEC,
-};
+struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie)
+{
+	return NULL;
+}
 
-static int dst_md_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
+u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old)
 {
-	WARN_ONCE(1, "Attempting to call output on metadata dst\n");
-	kfree_skb(skb);
-	return 0;
+	return NULL;
 }
 
-static int dst_md_discard(struct sk_buff *skb)
+struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
+					     struct sk_buff *skb,
+					     const void *daddr)
 {
-	WARN_ONCE(1, "Attempting to call input on metadata dst\n");
-	kfree_skb(skb);
-	return 0;
+	return NULL;
+}
+
+void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
+			       struct sk_buff *skb, u32 mtu,
+			       bool confirm_neigh)
+{
+}
+EXPORT_SYMBOL_GPL(dst_blackhole_update_pmtu);
+
+void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
+			    struct sk_buff *skb)
+{
+}
+EXPORT_SYMBOL_GPL(dst_blackhole_redirect);
+
+unsigned int dst_blackhole_mtu(const struct dst_entry *dst)
+{
+	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
+
+	return mtu ? : dst->dev->mtu;
 }
+EXPORT_SYMBOL_GPL(dst_blackhole_mtu);
+
+static struct dst_ops dst_blackhole_ops = {
+	.family		= AF_UNSPEC,
+	.neigh_lookup	= dst_blackhole_neigh_lookup,
+	.check		= dst_blackhole_check,
+	.cow_metrics	= dst_blackhole_cow_metrics,
+	.update_pmtu	= dst_blackhole_update_pmtu,
+	.redirect	= dst_blackhole_redirect,
+	.mtu		= dst_blackhole_mtu,
+};
 
 static void __metadata_dst_init(struct metadata_dst *md_dst,
 				enum metadata_type type, u8 optslen)
-
 {
 	struct dst_entry *dst;
 
 	dst = &md_dst->dst;
-	dst_init(dst, &md_dst_ops, NULL, 1, DST_OBSOLETE_NONE,
+	dst_init(dst, &dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE,
 		 DST_METADATA | DST_NOCOUNT);
-
-	dst->input = dst_md_discard;
-	dst->output = dst_md_discard_out;
-
 	memset(dst + 1, 0, sizeof(*md_dst) + optslen - sizeof(*dst));
 	md_dst->type = type;
 }