vxlan: add ipv6 support

This patch adds IPv6 support to vxlan device, as the new version
RFC already mentions it:

   http://tools.ietf.org/html/draft-mahalingam-dutt-dcops-vxlan-03

Cc: David Stevens <dlstevens@us.ibm.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/vxlan.h

@@ -25,7 +25,7 @@ struct vxlan_sock {
 
 struct vxlan_sock *vxlan_sock_add(struct net *net, __be16 port,
 				  vxlan_rcv_t *rcv, void *data,
-				  bool no_share);
+				  bool no_share, bool ipv6);
 
 void vxlan_sock_release(struct vxlan_sock *vs);
 

include/uapi/linux/if_link.h

@@ -314,6 +314,8 @@ enum {
 	IFLA_VXLAN_L2MISS,
 	IFLA_VXLAN_L3MISS,
 	IFLA_VXLAN_PORT,	/* destination port */
+	IFLA_VXLAN_GROUP6,
+	IFLA_VXLAN_LOCAL6,
 	__IFLA_VXLAN_MAX
 };
 #define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)

net/openvswitch/vport-vxlan.c

@@ -123,7 +123,7 @@ static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
 	vxlan_port = vxlan_vport(vport);
 	strncpy(vxlan_port->name, parms->name, IFNAMSIZ);
 
-	vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true);
+	vs = vxlan_sock_add(net, htons(dst_port), vxlan_rcv, vport, true, false);
 	if (IS_ERR(vs)) {
 		ovs_vport_free(vport);
 		return (void *)vs;