net: Add Geneve tunneling protocol driver

This adds a device level support for Geneve -- Generic Network
Virtualization Encapsulation. The protocol is documented at
http://tools.ietf.org/html/draft-gross-geneve-01

Only protocol layer Geneve support is provided by this driver.
Openvswitch can be used for configuring, set up and tear down
functional Geneve tunnels.

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

include/net/geneve.h

@@ -0,0 +1,91 @@
+#ifndef __NET_GENEVE_H
+#define __NET_GENEVE_H  1
+
+#include <net/udp_tunnel.h>
+
+struct geneve_sock;
+
+typedef void (geneve_rcv_t)(struct geneve_sock *gs, struct sk_buff *skb);
+
+struct geneve_sock {
+	struct hlist_node	hlist;
+	geneve_rcv_t		*rcv;
+	void			*rcv_data;
+	struct work_struct	del_work;
+	struct socket		*sock;
+	struct rcu_head		rcu;
+	atomic_t		refcnt;
+	struct udp_offload	udp_offloads;
+};
+
+/* Geneve Header:
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |        Virtual Network Identifier (VNI)       |    Reserved   |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                    Variable Length Options                    |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Option Header:
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |          Option Class         |      Type     |R|R|R| Length  |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                      Variable Option Data                     |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+struct geneve_opt {
+	__be16	opt_class;
+	u8	type;
+#ifdef __LITTLE_ENDIAN_BITFIELD
+	u8	length:5;
+	u8	r3:1;
+	u8	r2:1;
+	u8	r1:1;
+#else
+	u8	r1:1;
+	u8	r2:1;
+	u8	r3:1;
+	u8	length:5;
+#endif
+	u8	opt_data[];
+};
+
+#define GENEVE_CRIT_OPT_TYPE (1 << 7)
+
+struct genevehdr {
+#ifdef __LITTLE_ENDIAN_BITFIELD
+	u8 opt_len:6;
+	u8 ver:2;
+	u8 rsvd1:6;
+	u8 critical:1;
+	u8 oam:1;
+#else
+	u8 ver:2;
+	u8 opt_len:6;
+	u8 oam:1;
+	u8 critical:1;
+	u8 rsvd1:6;
+#endif
+	__be16 proto_type;
+	u8 vni[3];
+	u8 rsvd2;
+	struct geneve_opt options[];
+};
+
+#define GENEVE_VER 0
+#define GENEVE_BASE_HLEN (sizeof(struct udphdr) + sizeof(struct genevehdr))
+
+struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
+				    geneve_rcv_t *rcv, void *data,
+				    bool no_share, bool ipv6);
+
+void geneve_sock_release(struct geneve_sock *vs);
+
+int geneve_xmit_skb(struct geneve_sock *gs, struct rtable *rt,
+		    struct sk_buff *skb, __be32 src, __be32 dst, __u8 tos,
+		    __u8 ttl, __be16 df, __be16 src_port, __be16 dst_port,
+		    __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
+		    bool xnet);
+#endif

include/net/ip_tunnels.h

@@ -95,6 +95,8 @@ struct ip_tunnel {
 #define TUNNEL_VERSION	__cpu_to_be16(0x40)
 #define TUNNEL_NO_KEY	__cpu_to_be16(0x80)
 #define TUNNEL_DONT_FRAGMENT    __cpu_to_be16(0x0100)
+#define TUNNEL_OAM	__cpu_to_be16(0x0200)
+#define TUNNEL_CRIT_OPT	__cpu_to_be16(0x0400)
 
 struct tnl_ptk_info {
 	__be16 flags;

net/ipv4/Kconfig

@@ -453,6 +453,20 @@ config TCP_CONG_BIC
 	increase provides TCP friendliness.
 	See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 
+config GENEVE
+	tristate "Generic Network Virtualization Encapsulation (Geneve)"
+	depends on INET
+	select NET_IP_TUNNEL
+	select NET_UDP_TUNNEL
+	---help---
+	This allows one to create Geneve virtual interfaces that provide
+	Layer 2 Networks over Layer 3 Networks. Geneve is often used
+	to tunnel virtual network infrastructure in virtualized environments.
+	For more information see:
+	  http://tools.ietf.org/html/draft-gross-geneve-01
+
+	  To compile this driver as a module, choose M here: the module
+
 config TCP_CONG_CUBIC
 	tristate "CUBIC TCP"
 	default y

net/ipv4/Makefile

@@ -56,6 +56,7 @@ obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
 obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
 obj-$(CONFIG_MEMCG_KMEM) += tcp_memcontrol.o
 obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
+obj-$(CONFIG_GENEVE) += geneve.o
 
 obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
 		      xfrm4_output.o xfrm4_protocol.o