net/ipv4/geneve.c - kernel/common - Git at Google

 /*
  * 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/list.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/ethtool.h>
 #include <linux/mutex.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

 /* Protects sock_list and refcounts. */
 static DEFINE_MUTEX(geneve_mutex);

 /* per-network namespace private data for this module */
 struct geneve_net {
 	struct list_head	sock_list;
 };

 static int geneve_net_id;

 static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
 {
 	return (struct genevehdr *)(udp_hdr(skb) + 1);
 }

 static struct geneve_sock *geneve_find_sock(struct net *net,
 					    sa_family_t family, __be16 port)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_sock *gs;

 	list_for_each_entry(gs, &gn->sock_list, list) {
 		if (inet_sk(gs->sock->sk)->inet_sport == port &&
 		    inet_sk(gs->sock->sk)->sk.sk_family == family)
 			return gs;
 	}

 	return NULL;
 }

 static void geneve_build_header(struct genevehdr *geneveh,
 				__be16 tun_flags, u8 vni[3],
 				u8 options_len, u8 *options)
 {
 	geneveh->ver = GENEVE_VER;
 	geneveh->opt_len = options_len / 4;
 	geneveh->oam = !!(tun_flags & TUNNEL_OAM);
 	geneveh->critical = !!(tun_flags & TUNNEL_CRIT_OPT);
 	geneveh->rsvd1 = 0;
 	memcpy(geneveh->vni, vni, 3);
 	geneveh->proto_type = htons(ETH_P_TEB);
 	geneveh->rsvd2 = 0;

 	memcpy(geneveh->options, options, options_len);
 }

 /* Transmit a fully formatted Geneve frame.
  *
  * When calling this function. The skb->data should point
  * to the geneve header which is fully formed.
  *
  * This function will add other UDP tunnel headers.
  */
 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 csum, bool xnet)
 {
 	struct genevehdr *gnvh;
 	int min_headroom;
 	int err;

 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
 			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
 			+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

 	err = skb_cow_head(skb, min_headroom);
 	if (unlikely(err)) {
 		kfree_skb(skb);
 		return err;
 	}

 	skb = vlan_hwaccel_push_inside(skb);
 	if (unlikely(!skb))
 		return -ENOMEM;

 	skb = udp_tunnel_handle_offloads(skb, csum);
 	if (IS_ERR(skb))
 		return PTR_ERR(skb);

 	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
 	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);

 	skb_set_inner_protocol(skb, htons(ETH_P_TEB));

 	return udp_tunnel_xmit_skb(rt, gs->sock->sk, skb, src, dst,
 				   tos, ttl, df, src_port, dst_port, xnet,
 				   !csum);
 }
 EXPORT_SYMBOL_GPL(geneve_xmit_skb);

 static int geneve_hlen(struct genevehdr *gh)
 {
 	return sizeof(*gh) + gh->opt_len * 4;
 }

 static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 					   struct sk_buff *skb,
 					   struct udp_offload *uoff)
 {
 	struct sk_buff *p, **pp = NULL;
 	struct genevehdr *gh, *gh2;
 	unsigned int hlen, gh_len, off_gnv;
 	const struct packet_offload *ptype;
 	__be16 type;
 	int flush = 1;

 	off_gnv = skb_gro_offset(skb);
 	hlen = off_gnv + sizeof(*gh);
 	gh = skb_gro_header_fast(skb, off_gnv);
 	if (skb_gro_header_hard(skb, hlen)) {
 		gh = skb_gro_header_slow(skb, hlen, off_gnv);
 		if (unlikely(!gh))
 			goto out;
 	}

 	if (gh->ver != GENEVE_VER || gh->oam)
 		goto out;
 	gh_len = geneve_hlen(gh);

 	hlen = off_gnv + gh_len;
 	if (skb_gro_header_hard(skb, hlen)) {
 		gh = skb_gro_header_slow(skb, hlen, off_gnv);
 		if (unlikely(!gh))
 			goto out;
 	}

 	flush = 0;

 	for (p = *head; p; p = p->next) {
 		if (!NAPI_GRO_CB(p)->same_flow)
 			continue;

 		gh2 = (struct genevehdr *)(p->data + off_gnv);
 		if (gh->opt_len != gh2->opt_len ||
 		    memcmp(gh, gh2, gh_len)) {
 			NAPI_GRO_CB(p)->same_flow = 0;
 			continue;
 		}
 	}

 	type = gh->proto_type;

 	rcu_read_lock();
 	ptype = gro_find_receive_by_type(type);
 	if (!ptype) {
 		flush = 1;
 		goto out_unlock;
 	}

 	skb_gro_pull(skb, gh_len);
 	skb_gro_postpull_rcsum(skb, gh, gh_len);
 	pp = ptype->callbacks.gro_receive(head, skb);

 out_unlock:
 	rcu_read_unlock();
 out:
 	NAPI_GRO_CB(skb)->flush |= flush;

 	return pp;
 }

 static int geneve_gro_complete(struct sk_buff *skb, int nhoff,
 			       struct udp_offload *uoff)
 {
 	struct genevehdr *gh;
 	struct packet_offload *ptype;
 	__be16 type;
 	int gh_len;
 	int err = -ENOSYS;

 	udp_tunnel_gro_complete(skb, nhoff);

 	gh = (struct genevehdr *)(skb->data + nhoff);
 	gh_len = geneve_hlen(gh);
 	type = gh->proto_type;

 	rcu_read_lock();
 	ptype = gro_find_complete_by_type(type);
 	if (ptype)
 		err = ptype->callbacks.gro_complete(skb, nhoff + gh_len);

 	rcu_read_unlock();
 	return err;
 }

 static void geneve_notify_add_rx_port(struct geneve_sock *gs)
 {
 	struct sock *sk = gs->sock->sk;
 	sa_family_t sa_family = sk->sk_family;
 	int err;

 	if (sa_family == AF_INET) {
 		err = udp_add_offload(&gs->udp_offloads);
 		if (err)
 			pr_warn("geneve: udp_add_offload failed with status %d\n",
 				err);
 	}
 }

 static void geneve_notify_del_rx_port(struct geneve_sock *gs)
 {
 	struct sock *sk = gs->sock->sk;
 	sa_family_t sa_family = sk->sk_family;

 	if (sa_family == AF_INET)
 		udp_del_offload(&gs->udp_offloads);
 }

 /* Callback from net/ipv4/udp.c to receive packets */
 static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct genevehdr *geneveh;
 	struct geneve_sock *gs;
 	int opts_len;

 	/* Need Geneve and inner Ethernet header to be present */
 	if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
 		goto error;

 	/* Return packets with reserved bits set */
 	geneveh = geneve_hdr(skb);

 	if (unlikely(geneveh->ver != GENEVE_VER))
 		goto error;

 	if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
 		goto error;

 	opts_len = geneveh->opt_len * 4;
 	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
 				 htons(ETH_P_TEB)))
 		goto drop;

 	gs = rcu_dereference_sk_user_data(sk);
 	if (!gs)
 		goto drop;

 	gs->rcv(gs, skb);
 	return 0;

 drop:
 	/* Consume bad packet */
 	kfree_skb(skb);
 	return 0;

 error:
 	/* Let the UDP layer deal with the skb */
 	return 1;
 }

 static struct socket *geneve_create_sock(struct net *net, bool ipv6,
 					 __be16 port)
 {
 	struct socket *sock;
 	struct udp_port_cfg udp_conf;
 	int err;

 	memset(&udp_conf, 0, sizeof(udp_conf));

 	if (ipv6) {
 		udp_conf.family = AF_INET6;
 	} else {
 		udp_conf.family = AF_INET;
 		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
 	}

 	udp_conf.local_udp_port = port;

 	/* Open UDP socket */
 	err = udp_sock_create(net, &udp_conf, &sock);
 	if (err < 0)
 		return ERR_PTR(err);

 	return sock;
 }

 /* Create new listen socket if needed */
 static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
 						geneve_rcv_t *rcv, void *data,
 						bool ipv6)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_sock *gs;
 	struct socket *sock;
 	struct udp_tunnel_sock_cfg tunnel_cfg;

 	gs = kzalloc(sizeof(*gs), GFP_KERNEL);
 	if (!gs)
 		return ERR_PTR(-ENOMEM);

 	sock = geneve_create_sock(net, ipv6, port);
 	if (IS_ERR(sock)) {
 		kfree(gs);
 		return ERR_CAST(sock);
 	}

 	gs->sock = sock;
 	gs->refcnt = 1;
 	gs->rcv = rcv;
 	gs->rcv_data = data;

 	/* Initialize the geneve udp offloads structure */
 	gs->udp_offloads.port = port;
 	gs->udp_offloads.callbacks.gro_receive  = geneve_gro_receive;
 	gs->udp_offloads.callbacks.gro_complete = geneve_gro_complete;
 	geneve_notify_add_rx_port(gs);

 	/* Mark socket as an encapsulation socket */
 	tunnel_cfg.sk_user_data = gs;
 	tunnel_cfg.encap_type = 1;
 	tunnel_cfg.encap_rcv = geneve_udp_encap_recv;
 	tunnel_cfg.encap_destroy = NULL;
 	setup_udp_tunnel_sock(net, sock, &tunnel_cfg);

 	list_add(&gs->list, &gn->sock_list);

 	return gs;
 }

 struct geneve_sock *geneve_sock_add(struct net *net, __be16 port,
 				    geneve_rcv_t *rcv, void *data,
 				    bool no_share, bool ipv6)
 {
 	struct geneve_sock *gs;

 	mutex_lock(&geneve_mutex);

 	gs = geneve_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port);
 	if (gs) {
 		if (!no_share && gs->rcv == rcv)
 			gs->refcnt++;
 		else
 			gs = ERR_PTR(-EBUSY);
 	} else {
 		gs = geneve_socket_create(net, port, rcv, data, ipv6);
 	}

 	mutex_unlock(&geneve_mutex);

 	return gs;
 }
 EXPORT_SYMBOL_GPL(geneve_sock_add);

 void geneve_sock_release(struct geneve_sock *gs)
 {
 	mutex_lock(&geneve_mutex);

 	if (--gs->refcnt)
 		goto unlock;

 	list_del(&gs->list);
 	geneve_notify_del_rx_port(gs);
 	udp_tunnel_sock_release(gs->sock);
 	kfree_rcu(gs, rcu);

 unlock:
 	mutex_unlock(&geneve_mutex);
 }
 EXPORT_SYMBOL_GPL(geneve_sock_release);

 static __net_init int geneve_init_net(struct net *net)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);

 	INIT_LIST_HEAD(&gn->sock_list);

 	return 0;
 }

 static struct pernet_operations geneve_net_ops = {
 	.init = geneve_init_net,
 	.id   = &geneve_net_id,
 	.size = sizeof(struct geneve_net),
 };

 static int __init geneve_init_module(void)
 {
 	int rc;

 	rc = register_pernet_subsys(&geneve_net_ops);
 	if (rc)
 		return rc;

 	pr_info("Geneve driver\n");

 	return 0;
 }
 module_init(geneve_init_module);

 static void __exit geneve_cleanup_module(void)
 {
 	unregister_pernet_subsys(&geneve_net_ops);
 }
 module_exit(geneve_cleanup_module);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Jesse Gross <[email protected]>");
 MODULE_DESCRIPTION("Driver for GENEVE encapsulated traffic");
 MODULE_ALIAS_RTNL_LINK("geneve");
	/*
	* 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/list.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/ethtool.h>
	#include <linux/mutex.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

	/* Protects sock_list and refcounts. */
	static DEFINE_MUTEX(geneve_mutex);

	/* per-network namespace private data for this module */
	struct geneve_net {
	struct list_head sock_list;
	};

	static int geneve_net_id;

	static inline struct genevehdr geneve_hdr(const struct sk_buff skb)
	{
	return (struct genevehdr *)(udp_hdr(skb) + 1);
	}

	static struct geneve_sock geneve_find_sock(struct net net,
	sa_family_t family, __be16 port)
	{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_sock *gs;

	list_for_each_entry(gs, &gn->sock_list, list) {
	if (inet_sk(gs->sock->sk)->inet_sport == port &&
	inet_sk(gs->sock->sk)->sk.sk_family == family)
	return gs;
	}

	return NULL;
	}

	static void geneve_build_header(struct genevehdr *geneveh,
	__be16 tun_flags, u8 vni[3],
	u8 options_len, u8 *options)
	{
	geneveh->ver = GENEVE_VER;
	geneveh->opt_len = options_len / 4;
	geneveh->oam = !!(tun_flags & TUNNEL_OAM);
	geneveh->critical = !!(tun_flags & TUNNEL_CRIT_OPT);
	geneveh->rsvd1 = 0;
	memcpy(geneveh->vni, vni, 3);
	geneveh->proto_type = htons(ETH_P_TEB);
	geneveh->rsvd2 = 0;

	memcpy(geneveh->options, options, options_len);
	}

	/* Transmit a fully formatted Geneve frame.
	*
	* When calling this function. The skb->data should point
	* to the geneve header which is fully formed.
	*
	* This function will add other UDP tunnel headers.
	*/
	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 csum, bool xnet)
	{
	struct genevehdr *gnvh;
	int min_headroom;
	int err;

	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
	+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr)
	+ (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);

	err = skb_cow_head(skb, min_headroom);
	if (unlikely(err)) {
	kfree_skb(skb);
	return err;
	}

	skb = vlan_hwaccel_push_inside(skb);
	if (unlikely(!skb))
	return -ENOMEM;

	skb = udp_tunnel_handle_offloads(skb, csum);
	if (IS_ERR(skb))
	return PTR_ERR(skb);

	gnvh = (struct genevehdr )__skb_push(skb, sizeof(gnvh) + opt_len);
	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);

	skb_set_inner_protocol(skb, htons(ETH_P_TEB));

	return udp_tunnel_xmit_skb(rt, gs->sock->sk, skb, src, dst,
	tos, ttl, df, src_port, dst_port, xnet,
	!csum);
	}
	EXPORT_SYMBOL_GPL(geneve_xmit_skb);

	static int geneve_hlen(struct genevehdr *gh)
	{
	return sizeof(gh) + gh->opt_len 4;
	}

	static struct sk_buff geneve_gro_receive(struct sk_buff head,
	struct sk_buff *skb,
	struct udp_offload *uoff)
	{
	struct sk_buff p, *pp = NULL;
	struct genevehdr gh, gh2;
	unsigned int hlen, gh_len, off_gnv;
	const struct packet_offload *ptype;
	__be16 type;
	int flush = 1;

	off_gnv = skb_gro_offset(skb);
	hlen = off_gnv + sizeof(*gh);
	gh = skb_gro_header_fast(skb, off_gnv);
	if (skb_gro_header_hard(skb, hlen)) {
	gh = skb_gro_header_slow(skb, hlen, off_gnv);
	if (unlikely(!gh))
	goto out;
	}

	if (gh->ver != GENEVE_VER \|\| gh->oam)
	goto out;
	gh_len = geneve_hlen(gh);

	hlen = off_gnv + gh_len;
	if (skb_gro_header_hard(skb, hlen)) {
	gh = skb_gro_header_slow(skb, hlen, off_gnv);
	if (unlikely(!gh))
	goto out;
	}

	flush = 0;

	for (p = *head; p; p = p->next) {
	if (!NAPI_GRO_CB(p)->same_flow)
	continue;

	gh2 = (struct genevehdr *)(p->data + off_gnv);
	if (gh->opt_len != gh2->opt_len \|\|
	memcmp(gh, gh2, gh_len)) {
	NAPI_GRO_CB(p)->same_flow = 0;
	continue;
	}
	}

	type = gh->proto_type;

	rcu_read_lock();
	ptype = gro_find_receive_by_type(type);
	if (!ptype) {
	flush = 1;
	goto out_unlock;
	}

	skb_gro_pull(skb, gh_len);
	skb_gro_postpull_rcsum(skb, gh, gh_len);
	pp = ptype->callbacks.gro_receive(head, skb);

	out_unlock:
	rcu_read_unlock();
	out:
	NAPI_GRO_CB(skb)->flush \|= flush;

	return pp;
	}

	static int geneve_gro_complete(struct sk_buff *skb, int nhoff,
	struct udp_offload *uoff)
	{
	struct genevehdr *gh;
	struct packet_offload *ptype;
	__be16 type;
	int gh_len;
	int err = -ENOSYS;

	udp_tunnel_gro_complete(skb, nhoff);

	gh = (struct genevehdr *)(skb->data + nhoff);
	gh_len = geneve_hlen(gh);
	type = gh->proto_type;

	rcu_read_lock();
	ptype = gro_find_complete_by_type(type);
	if (ptype)
	err = ptype->callbacks.gro_complete(skb, nhoff + gh_len);

	rcu_read_unlock();
	return err;
	}

	static void geneve_notify_add_rx_port(struct geneve_sock *gs)
	{
	struct sock *sk = gs->sock->sk;
	sa_family_t sa_family = sk->sk_family;
	int err;

	if (sa_family == AF_INET) {
	err = udp_add_offload(&gs->udp_offloads);
	if (err)
	pr_warn("geneve: udp_add_offload failed with status %d\n",
	err);
	}
	}

	static void geneve_notify_del_rx_port(struct geneve_sock *gs)
	{
	struct sock *sk = gs->sock->sk;
	sa_family_t sa_family = sk->sk_family;

	if (sa_family == AF_INET)
	udp_del_offload(&gs->udp_offloads);
	}

	/* Callback from net/ipv4/udp.c to receive packets */
	static int geneve_udp_encap_recv(struct sock sk, struct sk_buff skb)
	{
	struct genevehdr *geneveh;
	struct geneve_sock *gs;
	int opts_len;

	/* Need Geneve and inner Ethernet header to be present */
	if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
	goto error;

	/* Return packets with reserved bits set */
	geneveh = geneve_hdr(skb);

	if (unlikely(geneveh->ver != GENEVE_VER))
	goto error;

	if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
	goto error;

	opts_len = geneveh->opt_len * 4;
	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
	htons(ETH_P_TEB)))
	goto drop;

	gs = rcu_dereference_sk_user_data(sk);
	if (!gs)
	goto drop;

	gs->rcv(gs, skb);
	return 0;

	drop:
	/* Consume bad packet */
	kfree_skb(skb);
	return 0;

	error:
	/* Let the UDP layer deal with the skb */
	return 1;
	}

	static struct socket geneve_create_sock(struct net net, bool ipv6,
	__be16 port)
	{
	struct socket *sock;
	struct udp_port_cfg udp_conf;
	int err;

	memset(&udp_conf, 0, sizeof(udp_conf));

	if (ipv6) {
	udp_conf.family = AF_INET6;
	} else {
	udp_conf.family = AF_INET;
	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
	}

	udp_conf.local_udp_port = port;

	/* Open UDP socket */
	err = udp_sock_create(net, &udp_conf, &sock);
	if (err < 0)
	return ERR_PTR(err);

	return sock;
	}

	/* Create new listen socket if needed */
	static struct geneve_sock geneve_socket_create(struct net net, __be16 port,
	geneve_rcv_t rcv, void data,
	bool ipv6)
	{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_sock *gs;
	struct socket *sock;
	struct udp_tunnel_sock_cfg tunnel_cfg;

	gs = kzalloc(sizeof(*gs), GFP_KERNEL);
	if (!gs)
	return ERR_PTR(-ENOMEM);

	sock = geneve_create_sock(net, ipv6, port);
	if (IS_ERR(sock)) {
	kfree(gs);
	return ERR_CAST(sock);
	}

	gs->sock = sock;
	gs->refcnt = 1;
	gs->rcv = rcv;
	gs->rcv_data = data;

	/* Initialize the geneve udp offloads structure */
	gs->udp_offloads.port = port;
	gs->udp_offloads.callbacks.gro_receive = geneve_gro_receive;
	gs->udp_offloads.callbacks.gro_complete = geneve_gro_complete;
	geneve_notify_add_rx_port(gs);

	/* Mark socket as an encapsulation socket */
	tunnel_cfg.sk_user_data = gs;
	tunnel_cfg.encap_type = 1;
	tunnel_cfg.encap_rcv = geneve_udp_encap_recv;
	tunnel_cfg.encap_destroy = NULL;
	setup_udp_tunnel_sock(net, sock, &tunnel_cfg);

	list_add(&gs->list, &gn->sock_list);

	return gs;
	}

	struct geneve_sock geneve_sock_add(struct net net, __be16 port,
	geneve_rcv_t rcv, void data,
	bool no_share, bool ipv6)
	{
	struct geneve_sock *gs;

	mutex_lock(&geneve_mutex);

	gs = geneve_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port);
	if (gs) {
	if (!no_share && gs->rcv == rcv)
	gs->refcnt++;
	else
	gs = ERR_PTR(-EBUSY);
	} else {
	gs = geneve_socket_create(net, port, rcv, data, ipv6);
	}

	mutex_unlock(&geneve_mutex);

	return gs;
	}
	EXPORT_SYMBOL_GPL(geneve_sock_add);

	void geneve_sock_release(struct geneve_sock *gs)
	{
	mutex_lock(&geneve_mutex);

	if (--gs->refcnt)
	goto unlock;

	list_del(&gs->list);
	geneve_notify_del_rx_port(gs);
	udp_tunnel_sock_release(gs->sock);
	kfree_rcu(gs, rcu);

	unlock:
	mutex_unlock(&geneve_mutex);
	}
	EXPORT_SYMBOL_GPL(geneve_sock_release);

	static __net_init int geneve_init_net(struct net *net)
	{
	struct geneve_net *gn = net_generic(net, geneve_net_id);

	INIT_LIST_HEAD(&gn->sock_list);

	return 0;
	}

	static struct pernet_operations geneve_net_ops = {
	.init = geneve_init_net,
	.id = &geneve_net_id,
	.size = sizeof(struct geneve_net),
	};

	static int __init geneve_init_module(void)
	{
	int rc;

	rc = register_pernet_subsys(&geneve_net_ops);
	if (rc)
	return rc;

	pr_info("Geneve driver\n");

	return 0;
	}
	module_init(geneve_init_module);

	static void __exit geneve_cleanup_module(void)
	{
	unregister_pernet_subsys(&geneve_net_ops);
	}
	module_exit(geneve_cleanup_module);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Jesse Gross <[email protected]>");
	MODULE_DESCRIPTION("Driver for GENEVE encapsulated traffic");
	MODULE_ALIAS_RTNL_LINK("geneve");