udp-tunnel: Add a few more UDP tunnel APIs

Added a few more UDP tunnel APIs that can be shared by UDP based
tunnel protocol implementation. The main ones are highlighted below.

setup_udp_tunnel_sock() configures UDP listener socket for
receiving UDP encapsulated packets.

udp_tunnel_xmit_skb() and upd_tunnel6_xmit_skb() transmit skb
using UDP encapsulation.

udp_tunnel_sock_release() closes the UDP tunnel listener socket.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 57 insertions, 0 deletions

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 0b9e017c9038..a47790bcaa38 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -1,6 +1,14 @@
 #ifndef __NET_UDP_TUNNEL_H
 #define __NET_UDP_TUNNEL_H
 
+#include <net/ip_tunnels.h>
+#include <net/udp.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/addrconf.h>
+#endif
+
 struct udp_port_cfg {
 	u8			family;
 
@@ -53,4 +61,53 @@ static inline int udp_sock_create(struct net *net,
 	return -EPFNOSUPPORT;
 }
 
+typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
+typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
+
+struct udp_tunnel_sock_cfg {
+	void *sk_user_data;     /* user data used by encap_rcv call back */
+	/* Used for setting up udp_sock fields, see udp.h for details */
+	__u8  encap_type;
+	udp_tunnel_encap_rcv_t encap_rcv;
+	udp_tunnel_encap_destroy_t encap_destroy;
+};
+
+/* Setup the given (UDP) sock to receive UDP encapsulated packets */
+void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
+			   struct udp_tunnel_sock_cfg *sock_cfg);
+
+/* Transmit the skb using UDP encapsulation. */
+int udp_tunnel_xmit_skb(struct socket *sock, struct rtable *rt,
+			struct sk_buff *skb, __be32 src, __be32 dst,
+			__u8 tos, __u8 ttl, __be16 df, __be16 src_port,
+			__be16 dst_port, bool xnet);
+
+#if IS_ENABLED(CONFIG_IPV6)
+int udp_tunnel6_xmit_skb(struct socket *sock, struct dst_entry *dst,
+			 struct sk_buff *skb, struct net_device *dev,
+			 struct in6_addr *saddr, struct in6_addr *daddr,
+			 __u8 prio, __u8 ttl, __be16 src_port,
+			 __be16 dst_port);
+#endif
+
+void udp_tunnel_sock_release(struct socket *sock);
+
+static inline struct sk_buff *udp_tunnel_handle_offloads(struct sk_buff *skb,
+							 bool udp_csum)
+{
+	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+
+	return iptunnel_handle_offloads(skb, udp_csum, type);
+}
+
+static inline void udp_tunnel_encap_enable(struct socket *sock)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sock->sk->sk_family == PF_INET6)
+		ipv6_stub->udpv6_encap_enable();
+	else
+#endif
+		udp_encap_enable();
+}
+
 #endif