l2tp_udp_encap_recv
EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv);
.encap_rcv = l2tp_udp_encap_recv,
int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
rc = l2tp_udp_encap_recv(sk, skb);