net/ipv4/fou.c - kernel/msm-4.9 - Gitiles

 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
 #include <linux/udp.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <net/genetlink.h>
 #include <net/gue.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/udp.h>
 #include <net/udp_tunnel.h>
 #include <net/xfrm.h>
 #include <uapi/linux/fou.h>
 #include <uapi/linux/genetlink.h>

 static DEFINE_SPINLOCK(fou_lock);
 static LIST_HEAD(fou_list);

 struct fou {
 	struct socket *sock;
 	u8 protocol;
 	u16 port;
 	struct udp_offload udp_offloads;
 	struct list_head list;
 };

 struct fou_cfg {
 	u16 type;
 	u8 protocol;
 	struct udp_port_cfg udp_config;
 };

 static inline struct fou *fou_from_sock(struct sock *sk)
 {
 	return sk->sk_user_data;
 }

 static int fou_udp_encap_recv_deliver(struct sk_buff *skb,
 				      u8 protocol, size_t len)
 {
 	struct iphdr *iph = ip_hdr(skb);

 	/* Remove 'len' bytes from the packet (UDP header and
 	 * FOU header if present), modify the protocol to the one
 	 * we found, and then call rcv_encap.
 	 */
 	iph->tot_len = htons(ntohs(iph->tot_len) - len);
 	__skb_pull(skb, len);
 	skb_postpull_rcsum(skb, udp_hdr(skb), len);
 	skb_reset_transport_header(skb);

 	return -protocol;
 }

 static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct fou *fou = fou_from_sock(sk);

 	if (!fou)
 		return 1;

 	return fou_udp_encap_recv_deliver(skb, fou->protocol,
 					  sizeof(struct udphdr));
 }

 static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct fou *fou = fou_from_sock(sk);
 	size_t len;
 	struct guehdr *guehdr;
 	struct udphdr *uh;

 	if (!fou)
 		return 1;

 	len = sizeof(struct udphdr) + sizeof(struct guehdr);
 	if (!pskb_may_pull(skb, len))
 		goto drop;

 	uh = udp_hdr(skb);
 	guehdr = (struct guehdr *)&uh[1];

 	len += guehdr->hlen << 2;
 	if (!pskb_may_pull(skb, len))
 		goto drop;

 	uh = udp_hdr(skb);
 	guehdr = (struct guehdr *)&uh[1];

 	if (guehdr->version != 0)
 		goto drop;

 	if (guehdr->flags) {
 		/* No support yet */
 		goto drop;
 	}

 	return fou_udp_encap_recv_deliver(skb, guehdr->next_hdr, len);
 drop:
 	kfree_skb(skb);
 	return 0;
 }

 static struct sk_buff **fou_gro_receive(struct sk_buff **head,
 					struct sk_buff *skb)
 {
 	const struct net_offload *ops;
 	struct sk_buff **pp = NULL;
 	u8 proto = NAPI_GRO_CB(skb)->proto;
 	const struct net_offload **offloads;

 	rcu_read_lock();
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
 	if (!ops || !ops->callbacks.gro_receive)
 		goto out_unlock;

 	pp = ops->callbacks.gro_receive(head, skb);

 out_unlock:
 	rcu_read_unlock();

 	return pp;
 }

 static int fou_gro_complete(struct sk_buff *skb, int nhoff)
 {
 	const struct net_offload *ops;
 	u8 proto = NAPI_GRO_CB(skb)->proto;
 	int err = -ENOSYS;
 	const struct net_offload **offloads;

 	rcu_read_lock();
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
 		goto out_unlock;

 	err = ops->callbacks.gro_complete(skb, nhoff);

 out_unlock:
 	rcu_read_unlock();

 	return err;
 }

 static struct sk_buff **gue_gro_receive(struct sk_buff **head,
 					struct sk_buff *skb)
 {
 	const struct net_offload **offloads;
 	const struct net_offload *ops;
 	struct sk_buff **pp = NULL;
 	struct sk_buff *p;
 	u8 proto;
 	struct guehdr *guehdr;
 	unsigned int hlen, guehlen;
 	unsigned int off;
 	int flush = 1;

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

 	proto = guehdr->next_hdr;

 	rcu_read_lock();
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
 	if (WARN_ON(!ops || !ops->callbacks.gro_receive))
 		goto out_unlock;

 	guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);

 	hlen = off + guehlen;
 	if (skb_gro_header_hard(skb, hlen)) {
 		guehdr = skb_gro_header_slow(skb, hlen, off);
 		if (unlikely(!guehdr))
 			goto out_unlock;
 	}

 	flush = 0;

 	for (p = *head; p; p = p->next) {
 		const struct guehdr *guehdr2;

 		if (!NAPI_GRO_CB(p)->same_flow)
 			continue;

 		guehdr2 = (struct guehdr *)(p->data + off);

 		/* Compare base GUE header to be equal (covers
 		 * hlen, version, next_hdr, and flags.
 		 */
 		if (guehdr->word != guehdr2->word) {
 			NAPI_GRO_CB(p)->same_flow = 0;
 			continue;
 		}

 		/* Compare optional fields are the same. */
 		if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
 					   guehdr->hlen << 2)) {
 			NAPI_GRO_CB(p)->same_flow = 0;
 			continue;
 		}
 	}

 	skb_gro_pull(skb, guehlen);

 	/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
 	skb_gro_postpull_rcsum(skb, guehdr, guehlen);

 	pp = ops->callbacks.gro_receive(head, skb);

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

 	return pp;
 }

 static int gue_gro_complete(struct sk_buff *skb, int nhoff)
 {
 	const struct net_offload **offloads;
 	struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
 	const struct net_offload *ops;
 	unsigned int guehlen;
 	u8 proto;
 	int err = -ENOENT;

 	proto = guehdr->next_hdr;

 	guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);

 	rcu_read_lock();
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
 		goto out_unlock;

 	err = ops->callbacks.gro_complete(skb, nhoff + guehlen);

 out_unlock:
 	rcu_read_unlock();
 	return err;
 }

 static int fou_add_to_port_list(struct fou *fou)
 {
 	struct fou *fout;

 	spin_lock(&fou_lock);
 	list_for_each_entry(fout, &fou_list, list) {
 		if (fou->port == fout->port) {
 			spin_unlock(&fou_lock);
 			return -EALREADY;
 		}
 	}

 	list_add(&fou->list, &fou_list);
 	spin_unlock(&fou_lock);

 	return 0;
 }

 static void fou_release(struct fou *fou)
 {
 	struct socket *sock = fou->sock;
 	struct sock *sk = sock->sk;

 	udp_del_offload(&fou->udp_offloads);

 	list_del(&fou->list);

 	/* Remove hooks into tunnel socket */
 	sk->sk_user_data = NULL;

 	sock_release(sock);

 	kfree(fou);
 }

 static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
 {
 	udp_sk(sk)->encap_rcv = fou_udp_recv;
 	fou->protocol = cfg->protocol;
 	fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
 	fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
 	fou->udp_offloads.port = cfg->udp_config.local_udp_port;
 	fou->udp_offloads.ipproto = cfg->protocol;

 	return 0;
 }

 static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
 {
 	udp_sk(sk)->encap_rcv = gue_udp_recv;
 	fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
 	fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
 	fou->udp_offloads.port = cfg->udp_config.local_udp_port;

 	return 0;
 }

 static int fou_create(struct net *net, struct fou_cfg *cfg,
 		      struct socket **sockp)
 {
 	struct fou *fou = NULL;
 	int err;
 	struct socket *sock = NULL;
 	struct sock *sk;

 	/* Open UDP socket */
 	err = udp_sock_create(net, &cfg->udp_config, &sock);
 	if (err < 0)
 		goto error;

 	/* Allocate FOU port structure */
 	fou = kzalloc(sizeof(*fou), GFP_KERNEL);
 	if (!fou) {
 		err = -ENOMEM;
 		goto error;
 	}

 	sk = sock->sk;

 	fou->port = cfg->udp_config.local_udp_port;

 	/* Initial for fou type */
 	switch (cfg->type) {
 	case FOU_ENCAP_DIRECT:
 		err = fou_encap_init(sk, fou, cfg);
 		if (err)
 			goto error;
 		break;
 	case FOU_ENCAP_GUE:
 		err = gue_encap_init(sk, fou, cfg);
 		if (err)
 			goto error;
 		break;
 	default:
 		err = -EINVAL;
 		goto error;
 	}

 	udp_sk(sk)->encap_type = 1;
 	udp_encap_enable();

 	sk->sk_user_data = fou;
 	fou->sock = sock;

 	udp_set_convert_csum(sk, true);

 	sk->sk_allocation = GFP_ATOMIC;

 	if (cfg->udp_config.family == AF_INET) {
 		err = udp_add_offload(&fou->udp_offloads);
 		if (err)
 			goto error;
 	}

 	err = fou_add_to_port_list(fou);
 	if (err)
 		goto error;

 	if (sockp)
 		*sockp = sock;

 	return 0;

 error:
 	kfree(fou);
 	if (sock)
 		sock_release(sock);

 	return err;
 }

 static int fou_destroy(struct net *net, struct fou_cfg *cfg)
 {
 	struct fou *fou;
 	u16 port = cfg->udp_config.local_udp_port;
 	int err = -EINVAL;

 	spin_lock(&fou_lock);
 	list_for_each_entry(fou, &fou_list, list) {
 		if (fou->port == port) {
 			udp_del_offload(&fou->udp_offloads);
 			fou_release(fou);
 			err = 0;
 			break;
 		}
 	}
 	spin_unlock(&fou_lock);

 	return err;
 }

 static struct genl_family fou_nl_family = {
 	.id		= GENL_ID_GENERATE,
 	.hdrsize	= 0,
 	.name		= FOU_GENL_NAME,
 	.version	= FOU_GENL_VERSION,
 	.maxattr	= FOU_ATTR_MAX,
 	.netnsok	= true,
 };

 static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
 	[FOU_ATTR_PORT] = { .type = NLA_U16, },
 	[FOU_ATTR_AF] = { .type = NLA_U8, },
 	[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
 	[FOU_ATTR_TYPE] = { .type = NLA_U8, },
 };

 static int parse_nl_config(struct genl_info *info,
 			   struct fou_cfg *cfg)
 {
 	memset(cfg, 0, sizeof(*cfg));

 	cfg->udp_config.family = AF_INET;

 	if (info->attrs[FOU_ATTR_AF]) {
 		u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);

 		if (family != AF_INET && family != AF_INET6)
 			return -EINVAL;

 		cfg->udp_config.family = family;
 	}

 	if (info->attrs[FOU_ATTR_PORT]) {
 		u16 port = nla_get_u16(info->attrs[FOU_ATTR_PORT]);

 		cfg->udp_config.local_udp_port = port;
 	}

 	if (info->attrs[FOU_ATTR_IPPROTO])
 		cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);

 	if (info->attrs[FOU_ATTR_TYPE])
 		cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);

 	return 0;
 }

 static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
 {
 	struct fou_cfg cfg;
 	int err;

 	err = parse_nl_config(info, &cfg);
 	if (err)
 		return err;

 	return fou_create(&init_net, &cfg, NULL);
 }

 static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
 {
 	struct fou_cfg cfg;

 	parse_nl_config(info, &cfg);

 	return fou_destroy(&init_net, &cfg);
 }

 static const struct genl_ops fou_nl_ops[] = {
 	{
 		.cmd = FOU_CMD_ADD,
 		.doit = fou_nl_cmd_add_port,
 		.policy = fou_nl_policy,
 		.flags = GENL_ADMIN_PERM,
 	},
 	{
 		.cmd = FOU_CMD_DEL,
 		.doit = fou_nl_cmd_rm_port,
 		.policy = fou_nl_policy,
 		.flags = GENL_ADMIN_PERM,
 	},
 };

 static int __init fou_init(void)
 {
 	int ret;

 	ret = genl_register_family_with_ops(&fou_nl_family,
 					    fou_nl_ops);

 	return ret;
 }

 static void __exit fou_fini(void)
 {
 	struct fou *fou, *next;

 	genl_unregister_family(&fou_nl_family);

 	/* Close all the FOU sockets */

 	spin_lock(&fou_lock);
 	list_for_each_entry_safe(fou, next, &fou_list, list)
 		fou_release(fou);
 	spin_unlock(&fou_lock);
 }

 module_init(fou_init);
 module_exit(fou_fini);
 MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
 MODULE_LICENSE("GPL");
	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/socket.h>
	#include <linux/skbuff.h>
	#include <linux/ip.h>
	#include <linux/udp.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <net/genetlink.h>
	#include <net/gue.h>
	#include <net/ip.h>
	#include <net/protocol.h>
	#include <net/udp.h>
	#include <net/udp_tunnel.h>
	#include <net/xfrm.h>
	#include <uapi/linux/fou.h>
	#include <uapi/linux/genetlink.h>

	static DEFINE_SPINLOCK(fou_lock);
	static LIST_HEAD(fou_list);

	struct fou {
	struct socket *sock;
	u8 protocol;
	u16 port;
	struct udp_offload udp_offloads;
	struct list_head list;
	};

	struct fou_cfg {
	u16 type;
	u8 protocol;
	struct udp_port_cfg udp_config;
	};

	static inline struct fou fou_from_sock(struct sock sk)
	{
	return sk->sk_user_data;
	}

	static int fou_udp_encap_recv_deliver(struct sk_buff *skb,
	u8 protocol, size_t len)
	{
	struct iphdr *iph = ip_hdr(skb);

	/* Remove 'len' bytes from the packet (UDP header and
	* FOU header if present), modify the protocol to the one
	* we found, and then call rcv_encap.
	*/
	iph->tot_len = htons(ntohs(iph->tot_len) - len);
	__skb_pull(skb, len);
	skb_postpull_rcsum(skb, udp_hdr(skb), len);
	skb_reset_transport_header(skb);

	return -protocol;
	}

	static int fou_udp_recv(struct sock sk, struct sk_buff skb)
	{
	struct fou *fou = fou_from_sock(sk);

	if (!fou)
	return 1;

	return fou_udp_encap_recv_deliver(skb, fou->protocol,
	sizeof(struct udphdr));
	}

	static int gue_udp_recv(struct sock sk, struct sk_buff skb)
	{
	struct fou *fou = fou_from_sock(sk);
	size_t len;
	struct guehdr *guehdr;
	struct udphdr *uh;

	if (!fou)
	return 1;

	len = sizeof(struct udphdr) + sizeof(struct guehdr);
	if (!pskb_may_pull(skb, len))
	goto drop;

	uh = udp_hdr(skb);
	guehdr = (struct guehdr *)&uh[1];

	len += guehdr->hlen << 2;
	if (!pskb_may_pull(skb, len))
	goto drop;

	uh = udp_hdr(skb);
	guehdr = (struct guehdr *)&uh[1];

	if (guehdr->version != 0)
	goto drop;

	if (guehdr->flags) {
	/* No support yet */
	goto drop;
	}

	return fou_udp_encap_recv_deliver(skb, guehdr->next_hdr, len);
	drop:
	kfree_skb(skb);
	return 0;
	}

	static struct sk_buff fou_gro_receive(struct sk_buff head,
	struct sk_buff *skb)
	{
	const struct net_offload *ops;
	struct sk_buff **pp = NULL;
	u8 proto = NAPI_GRO_CB(skb)->proto;
	const struct net_offload **offloads;

	rcu_read_lock();
	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
	ops = rcu_dereference(offloads[proto]);
	if (!ops \|\| !ops->callbacks.gro_receive)
	goto out_unlock;

	pp = ops->callbacks.gro_receive(head, skb);

	out_unlock:
	rcu_read_unlock();

	return pp;
	}

	static int fou_gro_complete(struct sk_buff *skb, int nhoff)
	{
	const struct net_offload *ops;
	u8 proto = NAPI_GRO_CB(skb)->proto;
	int err = -ENOSYS;
	const struct net_offload **offloads;

	rcu_read_lock();
	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
	ops = rcu_dereference(offloads[proto]);
	if (WARN_ON(!ops \|\| !ops->callbacks.gro_complete))
	goto out_unlock;

	err = ops->callbacks.gro_complete(skb, nhoff);

	out_unlock:
	rcu_read_unlock();

	return err;
	}

	static struct sk_buff gue_gro_receive(struct sk_buff head,
	struct sk_buff *skb)
	{
	const struct net_offload **offloads;
	const struct net_offload *ops;
	struct sk_buff **pp = NULL;
	struct sk_buff *p;
	u8 proto;
	struct guehdr *guehdr;
	unsigned int hlen, guehlen;
	unsigned int off;
	int flush = 1;

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

	proto = guehdr->next_hdr;

	rcu_read_lock();
	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
	ops = rcu_dereference(offloads[proto]);
	if (WARN_ON(!ops \|\| !ops->callbacks.gro_receive))
	goto out_unlock;

	guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);

	hlen = off + guehlen;
	if (skb_gro_header_hard(skb, hlen)) {
	guehdr = skb_gro_header_slow(skb, hlen, off);
	if (unlikely(!guehdr))
	goto out_unlock;
	}

	flush = 0;

	for (p = *head; p; p = p->next) {
	const struct guehdr *guehdr2;

	if (!NAPI_GRO_CB(p)->same_flow)
	continue;

	guehdr2 = (struct guehdr *)(p->data + off);

	/* Compare base GUE header to be equal (covers
	* hlen, version, next_hdr, and flags.
	*/
	if (guehdr->word != guehdr2->word) {
	NAPI_GRO_CB(p)->same_flow = 0;
	continue;
	}

	/* Compare optional fields are the same. */
	if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
	guehdr->hlen << 2)) {
	NAPI_GRO_CB(p)->same_flow = 0;
	continue;
	}
	}

	skb_gro_pull(skb, guehlen);

	/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
	skb_gro_postpull_rcsum(skb, guehdr, guehlen);

	pp = ops->callbacks.gro_receive(head, skb);

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

	return pp;
	}

	static int gue_gro_complete(struct sk_buff *skb, int nhoff)
	{
	const struct net_offload **offloads;
	struct guehdr guehdr = (struct guehdr )(skb->data + nhoff);
	const struct net_offload *ops;
	unsigned int guehlen;
	u8 proto;
	int err = -ENOENT;

	proto = guehdr->next_hdr;

	guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);

	rcu_read_lock();
	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
	ops = rcu_dereference(offloads[proto]);
	if (WARN_ON(!ops \|\| !ops->callbacks.gro_complete))
	goto out_unlock;

	err = ops->callbacks.gro_complete(skb, nhoff + guehlen);

	out_unlock:
	rcu_read_unlock();
	return err;
	}

	static int fou_add_to_port_list(struct fou *fou)
	{
	struct fou *fout;

	spin_lock(&fou_lock);
	list_for_each_entry(fout, &fou_list, list) {
	if (fou->port == fout->port) {
	spin_unlock(&fou_lock);
	return -EALREADY;
	}
	}

	list_add(&fou->list, &fou_list);
	spin_unlock(&fou_lock);

	return 0;
	}

	static void fou_release(struct fou *fou)
	{
	struct socket *sock = fou->sock;
	struct sock *sk = sock->sk;

	udp_del_offload(&fou->udp_offloads);

	list_del(&fou->list);

	/* Remove hooks into tunnel socket */
	sk->sk_user_data = NULL;

	sock_release(sock);

	kfree(fou);
	}

	static int fou_encap_init(struct sock sk, struct fou fou, struct fou_cfg *cfg)
	{
	udp_sk(sk)->encap_rcv = fou_udp_recv;
	fou->protocol = cfg->protocol;
	fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
	fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
	fou->udp_offloads.port = cfg->udp_config.local_udp_port;
	fou->udp_offloads.ipproto = cfg->protocol;

	return 0;
	}

	static int gue_encap_init(struct sock sk, struct fou fou, struct fou_cfg *cfg)
	{
	udp_sk(sk)->encap_rcv = gue_udp_recv;
	fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
	fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
	fou->udp_offloads.port = cfg->udp_config.local_udp_port;

	return 0;
	}

	static int fou_create(struct net net, struct fou_cfg cfg,
	struct socket **sockp)
	{
	struct fou *fou = NULL;
	int err;
	struct socket *sock = NULL;
	struct sock *sk;

	/* Open UDP socket */
	err = udp_sock_create(net, &cfg->udp_config, &sock);
	if (err < 0)
	goto error;

	/* Allocate FOU port structure */
	fou = kzalloc(sizeof(*fou), GFP_KERNEL);
	if (!fou) {
	err = -ENOMEM;
	goto error;
	}

	sk = sock->sk;

	fou->port = cfg->udp_config.local_udp_port;

	/* Initial for fou type */
	switch (cfg->type) {
	case FOU_ENCAP_DIRECT:
	err = fou_encap_init(sk, fou, cfg);
	if (err)
	goto error;
	break;
	case FOU_ENCAP_GUE:
	err = gue_encap_init(sk, fou, cfg);
	if (err)
	goto error;
	break;
	default:
	err = -EINVAL;
	goto error;
	}

	udp_sk(sk)->encap_type = 1;
	udp_encap_enable();

	sk->sk_user_data = fou;
	fou->sock = sock;

	udp_set_convert_csum(sk, true);

	sk->sk_allocation = GFP_ATOMIC;

	if (cfg->udp_config.family == AF_INET) {
	err = udp_add_offload(&fou->udp_offloads);
	if (err)
	goto error;
	}

	err = fou_add_to_port_list(fou);
	if (err)
	goto error;

	if (sockp)
	*sockp = sock;

	return 0;

	error:
	kfree(fou);
	if (sock)
	sock_release(sock);

	return err;
	}

	static int fou_destroy(struct net net, struct fou_cfg cfg)
	{
	struct fou *fou;
	u16 port = cfg->udp_config.local_udp_port;
	int err = -EINVAL;

	spin_lock(&fou_lock);
	list_for_each_entry(fou, &fou_list, list) {
	if (fou->port == port) {
	udp_del_offload(&fou->udp_offloads);
	fou_release(fou);
	err = 0;
	break;
	}
	}
	spin_unlock(&fou_lock);

	return err;
	}

	static struct genl_family fou_nl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = 0,
	.name = FOU_GENL_NAME,
	.version = FOU_GENL_VERSION,
	.maxattr = FOU_ATTR_MAX,
	.netnsok = true,
	};

	static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
	[FOU_ATTR_PORT] = { .type = NLA_U16, },
	[FOU_ATTR_AF] = { .type = NLA_U8, },
	[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
	[FOU_ATTR_TYPE] = { .type = NLA_U8, },
	};

	static int parse_nl_config(struct genl_info *info,
	struct fou_cfg *cfg)
	{
	memset(cfg, 0, sizeof(*cfg));

	cfg->udp_config.family = AF_INET;

	if (info->attrs[FOU_ATTR_AF]) {
	u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);

	if (family != AF_INET && family != AF_INET6)
	return -EINVAL;

	cfg->udp_config.family = family;
	}

	if (info->attrs[FOU_ATTR_PORT]) {
	u16 port = nla_get_u16(info->attrs[FOU_ATTR_PORT]);

	cfg->udp_config.local_udp_port = port;
	}

	if (info->attrs[FOU_ATTR_IPPROTO])
	cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);

	if (info->attrs[FOU_ATTR_TYPE])
	cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);

	return 0;
	}

	static int fou_nl_cmd_add_port(struct sk_buff skb, struct genl_info info)
	{
	struct fou_cfg cfg;
	int err;

	err = parse_nl_config(info, &cfg);
	if (err)
	return err;

	return fou_create(&init_net, &cfg, NULL);
	}

	static int fou_nl_cmd_rm_port(struct sk_buff skb, struct genl_info info)
	{
	struct fou_cfg cfg;

	parse_nl_config(info, &cfg);

	return fou_destroy(&init_net, &cfg);
	}

	static const struct genl_ops fou_nl_ops[] = {
	{
	.cmd = FOU_CMD_ADD,
	.doit = fou_nl_cmd_add_port,
	.policy = fou_nl_policy,
	.flags = GENL_ADMIN_PERM,
	},
	{
	.cmd = FOU_CMD_DEL,
	.doit = fou_nl_cmd_rm_port,
	.policy = fou_nl_policy,
	.flags = GENL_ADMIN_PERM,
	},
	};

	static int __init fou_init(void)
	{
	int ret;

	ret = genl_register_family_with_ops(&fou_nl_family,
	fou_nl_ops);

	return ret;
	}

	static void __exit fou_fini(void)
	{
	struct fou fou, next;

	genl_unregister_family(&fou_nl_family);

	/* Close all the FOU sockets */

	spin_lock(&fou_lock);
	list_for_each_entry_safe(fou, next, &fou_list, list)
	fou_release(fou);
	spin_unlock(&fou_lock);
	}

	module_init(fou_init);
	module_exit(fou_fini);
	MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
	MODULE_LICENSE("GPL");