vlan: introduce vid list with reference counting

This allows to keep track of vids needed to be in rx vlan filters of
devices even if they are used in bond/team etc.

vlan_info as well as vlan_group previously was, is allocated when first
vid is added and dealocated whan last vid is deleted.

vlan_group definition is moved to private header.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 160 insertions, 8 deletions

diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 544f9cb9678..329e0313e01 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -71,10 +71,10 @@ bool vlan_do_receive(struct sk_buff **skbp, bool last_handler)
 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
 					u16 vlan_id)
 {
-	struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);
+	struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
 
-	if (grp) {
-		return vlan_group_get_device(grp, vlan_id);
+	if (vlan_info) {
+		return vlan_group_get_device(&vlan_info->grp, vlan_id);
 	} else {
 		/*
 		 * Bonding slaves do not have grp assigned to themselves.
@@ -147,25 +147,177 @@ err_free:
 	return NULL;
 }
 
-int vlan_vid_add(struct net_device *dev, unsigned short vid)
+
+/*
+ * vlan info and vid list
+ */
+
+static void vlan_group_free(struct vlan_group *grp)
+{
+	int i;
+
+	for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
+		kfree(grp->vlan_devices_arrays[i]);
+}
+
+static void vlan_info_free(struct vlan_info *vlan_info)
+{
+	vlan_group_free(&vlan_info->grp);
+	kfree(vlan_info);
+}
+
+static void vlan_info_rcu_free(struct rcu_head *rcu)
+{
+	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
+}
+
+static struct vlan_info *vlan_info_alloc(struct net_device *dev)
+{
+	struct vlan_info *vlan_info;
+
+	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
+	if (!vlan_info)
+		return NULL;
+
+	vlan_info->real_dev = dev;
+	INIT_LIST_HEAD(&vlan_info->vid_list);
+	return vlan_info;
+}
+
+struct vlan_vid_info {
+	struct list_head list;
+	unsigned short vid;
+	int refcount;
+};
+
+static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
+					       unsigned short vid)
+{
+	struct vlan_vid_info *vid_info;
+
+	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
+		if (vid_info->vid == vid)
+			return vid_info;
+	}
+	return NULL;
+}
+
+static struct vlan_vid_info *vlan_vid_info_alloc(unsigned short vid)
+{
+	struct vlan_vid_info *vid_info;
+
+	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
+	if (!vid_info)
+		return NULL;
+	vid_info->vid = vid;
+
+	return vid_info;
+}
+
+static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
+			  struct vlan_vid_info **pvid_info)
 {
+	struct net_device *dev = vlan_info->real_dev;
 	const struct net_device_ops *ops = dev->netdev_ops;
+	struct vlan_vid_info *vid_info;
+	int err;
+
+	vid_info = vlan_vid_info_alloc(vid);
+	if (!vid_info)
+		return -ENOMEM;
 
 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
-	     ops->ndo_vlan_rx_add_vid) {
-		return ops->ndo_vlan_rx_add_vid(dev, vid);
+	    ops->ndo_vlan_rx_add_vid) {
+		err =  ops->ndo_vlan_rx_add_vid(dev, vid);
+		if (err) {
+			kfree(vid_info);
+			return err;
+		}
 	}
+	list_add(&vid_info->list, &vlan_info->vid_list);
+	vlan_info->nr_vids++;
+	*pvid_info = vid_info;
 	return 0;
 }
+
+int vlan_vid_add(struct net_device *dev, unsigned short vid)
+{
+	struct vlan_info *vlan_info;
+	struct vlan_vid_info *vid_info;
+	bool vlan_info_created = false;
+	int err;
+
+	ASSERT_RTNL();
+
+	vlan_info = rtnl_dereference(dev->vlan_info);
+	if (!vlan_info) {
+		vlan_info = vlan_info_alloc(dev);
+		if (!vlan_info)
+			return -ENOMEM;
+		vlan_info_created = true;
+	}
+	vid_info = vlan_vid_info_get(vlan_info, vid);
+	if (!vid_info) {
+		err = __vlan_vid_add(vlan_info, vid, &vid_info);
+		if (err)
+			goto out_free_vlan_info;
+	}
+	vid_info->refcount++;
+
+	if (vlan_info_created)
+		rcu_assign_pointer(dev->vlan_info, vlan_info);
+
+	return 0;
+
+out_free_vlan_info:
+	if (vlan_info_created)
+		kfree(vlan_info);
+	return err;
+}
 EXPORT_SYMBOL(vlan_vid_add);
 
-void vlan_vid_del(struct net_device *dev, unsigned short vid)
+static void __vlan_vid_del(struct vlan_info *vlan_info,
+			   struct vlan_vid_info *vid_info)
 {
+	struct net_device *dev = vlan_info->real_dev;
 	const struct net_device_ops *ops = dev->netdev_ops;
+	unsigned short vid = vid_info->vid;
+	int err;
 
 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 	     ops->ndo_vlan_rx_kill_vid) {
-		ops->ndo_vlan_rx_kill_vid(dev, vid);
+		err = ops->ndo_vlan_rx_kill_vid(dev, vid);
+		if (err) {
+			pr_warn("failed to kill vid %d for device %s\n",
+				vid, dev->name);
+		}
+	}
+	list_del(&vid_info->list);
+	kfree(vid_info);
+	vlan_info->nr_vids--;
+}
+
+void vlan_vid_del(struct net_device *dev, unsigned short vid)
+{
+	struct vlan_info *vlan_info;
+	struct vlan_vid_info *vid_info;
+
+	ASSERT_RTNL();
+
+	vlan_info = rtnl_dereference(dev->vlan_info);
+	if (!vlan_info)
+		return;
+
+	vid_info = vlan_vid_info_get(vlan_info, vid);
+	if (!vid_info)
+		return;
+	vid_info->refcount--;
+	if (vid_info->refcount == 0) {
+		__vlan_vid_del(vlan_info, vid_info);
+		if (vlan_info->nr_vids == 0) {
+			RCU_INIT_POINTER(dev->vlan_info, NULL);
+			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
+		}
 	}
 }
 EXPORT_SYMBOL(vlan_vid_del);