+int netlink_add_tap(struct netlink_tap *nt)
+{
+ if (unlikely(nt->dev->type != ARPHRD_NETLINK))
+ return -EINVAL;
+
+ spin_lock(&netlink_tap_lock);
+ list_add_rcu(&nt->list, &netlink_tap_all);
+ spin_unlock(&netlink_tap_lock);
+
+ if (nt->module)
+ __module_get(nt->module);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(netlink_add_tap);
+
+int __netlink_remove_tap(struct netlink_tap *nt)
+{
+ bool found = false;
+ struct netlink_tap *tmp;
+
+ spin_lock(&netlink_tap_lock);
+
+ list_for_each_entry(tmp, &netlink_tap_all, list) {
+ if (nt == tmp) {
+ list_del_rcu(&nt->list);
+ found = true;
+ goto out;
+ }
+ }
+
+ pr_warn("__netlink_remove_tap: %p not found\n", nt);
+out:
+ spin_unlock(&netlink_tap_lock);
+
+ if (found && nt->module)
+ module_put(nt->module);
+
+ return found ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(__netlink_remove_tap);
+
+int netlink_remove_tap(struct netlink_tap *nt)
+{
+ int ret;
+
+ ret = __netlink_remove_tap(nt);
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(netlink_remove_tap);
+
+static int __netlink_deliver_tap_skb(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct sk_buff *nskb;
+ int ret = -ENOMEM;
+
+ dev_hold(dev);
+ nskb = skb_clone(skb, GFP_ATOMIC);
+ if (nskb) {
+ nskb->dev = dev;
+ ret = dev_queue_xmit(nskb);
+ if (unlikely(ret > 0))
+ ret = net_xmit_errno(ret);
+ }
+
+ dev_put(dev);
+ return ret;
+}
+
+static void __netlink_deliver_tap(struct sk_buff *skb)
+{
+ int ret;
+ struct netlink_tap *tmp;
+
+ list_for_each_entry_rcu(tmp, &netlink_tap_all, list) {
+ ret = __netlink_deliver_tap_skb(skb, tmp->dev);
+ if (unlikely(ret))
+ break;
+ }
+}
+
+static void netlink_deliver_tap(struct sk_buff *skb)
+{
+ rcu_read_lock();
+
+ if (unlikely(!list_empty(&netlink_tap_all)))
+ __netlink_deliver_tap(skb);
+
+ rcu_read_unlock();
+}
+