[PATCH v4 net-next 3/8] vxlan: vnifilter: signal interrupted RTM_GETTUNNEL dumps

@@ -4758,6 +4758,10 @@ static int vxlan_netdevice_event(struct notifier_block *unused,
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
 
+	if ((event == NETDEV_REGISTER || event == NETDEV_UNREGISTER) &&
+	    netif_is_vxlan(dev))
+		vxlan_vnifilter_seq_inc(dev_net(dev));
+
 	if (event == NETDEV_UNREGISTER)
 		vxlan_handle_lowerdev_unregister(vn, dev);
 	else if (event == NETDEV_UDP_TUNNEL_PUSH_INFO)

@@ -22,6 +22,8 @@ struct vxlan_net {
 	/* sock_list is protected by rtnl lock */
 	struct hlist_head sock_list[PORT_HASH_SIZE];
 	struct notifier_block nexthop_notifier_block;
+	/* Generation counter for RTM_GETTUNNEL dumps */
+	atomic_t vnifilter_seq;
 };
 
 struct vxlan_fdb_key {

@@ -177,6 +179,13 @@ vxlan_vnifilter_lookup(struct vxlan_dev *vxlan, __be32 vni)
 				      vxlan_vni_rht_params);
 }
 
+static inline void vxlan_vnifilter_seq_inc(const struct net *net)
+{
+	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+
+	atomic_inc(&vn->vnifilter_seq);
+}
+
 /* vxlan_core.c */
 int vxlan_fdb_create(struct vxlan_dev *vxlan,
 		     const u8 *mac, union vxlan_addr *ip,

@@ -410,9 +410,22 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 
 	nlmsg_end(skb, nlh);
 
+	nl_dump_check_consistent(cb, nlh);
+
 	return err;
 }
 
+static u32 vxlan_vnifilter_base_seq(const struct net *net)
+{
+	const struct vxlan_net *vn = net_generic(net, vxlan_net_id);
+	u32 res = atomic_read(&vn->vnifilter_seq);
+
+	/* Must not return 0 (see nl_dump_check_consistent()) */
+	if (!res)
+		res = 0x80000000;
+	return res;
+}
+
 static int vxlan_vnifilter_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	int idx = 0, err = 0, s_idx = cb->args[0];

@@ -432,6 +445,9 @@ static int vxlan_vnifilter_dump(struct sk_buff *skb, struct netlink_callback *cb
 	}
 
 	rcu_read_lock();
+
+	cb->seq = vxlan_vnifilter_base_seq(net);
+
 	if (tmsg->ifindex) {
 		dev = dev_get_by_index_rcu(net, tmsg->ifindex);
 		if (!dev) {

@@ -691,13 +707,16 @@ static int vxlan_vni_update(struct vxlan_dev *vxlan,
 	if (ret)
 		return ret;
 
-	if (*changed)
+	if (*changed) {
+		vxlan_vnifilter_seq_inc(dev_net(vxlan->dev));
 		vxlan_vnifilter_notify(vxlan, vninode, RTM_NEWTUNNEL);
+	}
 
 	return 0;
 }
 
-static void __vxlan_vni_add_list(struct vxlan_vni_group *vg,
+static void __vxlan_vni_add_list(struct vxlan_dev *vxlan,
+				 struct vxlan_vni_group *vg,
 				 struct vxlan_vni_node *v)
 {
 	struct list_head *headp, *hpos;

@@ -713,13 +732,16 @@ static void __vxlan_vni_add_list(struct vxlan_vni_group *vg,
 	}
 	list_add_rcu(&v->vlist, hpos);
 	vg->num_vnis++;
+	vxlan_vnifilter_seq_inc(dev_net(vxlan->dev));
 }
 
-static void __vxlan_vni_del_list(struct vxlan_vni_group *vg,
+static void __vxlan_vni_del_list(struct vxlan_dev *vxlan,
+				 struct vxlan_vni_group *vg,
 				 struct vxlan_vni_node *v)
 {
 	list_del_rcu(&v->vlist);
 	vg->num_vnis--;
+	vxlan_vnifilter_seq_inc(dev_net(vxlan->dev));
 }
 
 static struct vxlan_vni_node *vxlan_vni_alloc(struct vxlan_dev *vxlan,

@@ -781,7 +803,7 @@ static int vxlan_vni_add(struct vxlan_dev *vxlan,
 		return err;
 	}
 
-	__vxlan_vni_add_list(vg, vninode);
+	__vxlan_vni_add_list(vxlan, vg, vninode);
 
 	if (vxlan->dev->flags & IFF_UP)
 		vxlan_vs_add_del_vninode(vxlan, vninode, false);

@@ -827,7 +849,7 @@ static int vxlan_vni_del(struct vxlan_dev *vxlan,
 	if (err)
 		goto out;
 
-	__vxlan_vni_del_list(vg, vninode);
+	__vxlan_vni_del_list(vxlan, vg, vninode);
 
 	vxlan_vnifilter_notify(vxlan, vninode, RTM_DELTUNNEL);
 

@@ -941,7 +963,7 @@ void vxlan_vnigroup_uninit(struct vxlan_dev *vxlan)
 #if IS_ENABLED(CONFIG_IPV6)
 		hlist_del_init_rcu(&v->hlist6.hlist);
 #endif
-		__vxlan_vni_del_list(vg, v);
+		__vxlan_vni_del_list(vxlan, vg, v);
 		vxlan_vnifilter_notify(vxlan, v, RTM_DELTUNNEL);
 		call_rcu(&v->rcu, vxlan_vni_node_rcu_free);
 	}