+/**
+ * ovpn_udp_output - transmit skb using udp-tunnel
+ * @peer: the destination peer
+ * @cache: dst cache
+ * @sk: the socket to send the packet over
+ * @skb: the packet to send
+ *
+ * rcu_read_lock should be held on entry.
+ * On return, the skb is consumed.
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+static int ovpn_udp_output(struct ovpn_peer *peer, struct dst_cache *cache,
+ struct sock *sk, struct sk_buff *skb)
+{
+ struct ovpn_bind *bind;
+ int ret;
+
+ /* set sk to null if skb is already orphaned */
+ if (!skb->destructor)
+ skb->sk = NULL;
+
+ /* always permit openvpn-created packets to be (outside) fragmented */
+ skb->ignore_df = 1;
+
+ rcu_read_lock();
+ bind = rcu_dereference(peer->bind);
+ if (unlikely(!bind)) {
+ net_warn_ratelimited("%s: no bind for remote peer %u\n",
+ netdev_name(peer->ovpn->dev), peer->id);
+ goto out;
+ }
+
+ switch (bind->remote.in4.sin_family) {
+ case AF_INET:
+ ret = ovpn_udp4_output(peer, bind, cache, sk, skb);
+ break;
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6:
+ ret = ovpn_udp6_output(peer, bind, cache, sk, skb);
+ break;
+#endif
+ default:
+ ret = -EAFNOSUPPORT;
+ break;
+ }
+
+out:
+ rcu_read_unlock();
+ return ret;