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>

5 files changed, 481 insertions, 0 deletions

diff --git a/include/net/geneve.h b/include/net/geneve.h
new file mode 100644
index 000000000000..ce98865318bf
--- /dev/null
+++ b/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
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 7f538ba6e267..a9ce1556d773 100644
--- a/include/net/ip_tunnels.h
+++ b/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;
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 69fb37854449..c2035447e649 100644
--- a/net/ipv4/Kconfig
+++ b/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
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index d8105787c199..518c04ed666e 100644
--- a/net/ipv4/Makefile
+++ b/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
diff --git a/net/ipv4/geneve.c b/net/ipv4/geneve.c
new file mode 100644
index 000000000000..f008c5515f48
--- /dev/null
+++ b/net/ipv4/geneve.c
@@ -0,0 +1,373 @@
+/*
+ * Geneve: Generic Network Virtualization Encapsulation
+ *
+ * Copyright (c) 2014 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/rculist.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/igmp.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/hash.h>
+#include <linux/ethtool.h>
+#include <net/arp.h>
+#include <net/ndisc.h>
+#include <net/ip.h>
+#include <net/ip_tunnels.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/rtnetlink.h>
+#include <net/route.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/geneve.h>
+#include <net/protocol.h>
+#include <net/udp_tunnel.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/addrconf.h>
+#include <net/ip6_tunnel.h>
+#include <net/ip6_checksum.h>
+#endif
+
+#define PORT_HASH_BITS 8