drivers/net/geneve.c - pub/scm/linux/kernel/git/dacohen/intel-mid - Git at Google

 /*
  * GENEVE: Generic Network Virtualization Encapsulation
  *
  * Copyright (c) 2015 Red Hat, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/hash.h>
 #include <net/rtnetlink.h>
 #include <net/geneve.h>

 #define GENEVE_NETDEV_VER	"0.6"

 #define GENEVE_UDP_PORT		6081

 #define GENEVE_N_VID		(1u << 24)
 #define GENEVE_VID_MASK		(GENEVE_N_VID - 1)

 #define VNI_HASH_BITS		10
 #define VNI_HASH_SIZE		(1<<VNI_HASH_BITS)

 static bool log_ecn_error = true;
 module_param(log_ecn_error, bool, 0644);
 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");

 /* per-network namespace private data for this module */
 struct geneve_net {
 	struct list_head  geneve_list;
 	struct hlist_head vni_list[VNI_HASH_SIZE];
 };

 /* Pseudo network device */
 struct geneve_dev {
 	struct hlist_node  hlist;	/* vni hash table */
 	struct net	   *net;	/* netns for packet i/o */
 	struct net_device  *dev;	/* netdev for geneve tunnel */
 	struct geneve_sock *sock;	/* socket used for geneve tunnel */
 	u8                 vni[3];	/* virtual network ID for tunnel */
 	u8                 ttl;		/* TTL override */
 	u8                 tos;		/* TOS override */
 	struct sockaddr_in remote;	/* IPv4 address for link partner */
 	struct list_head   next;	/* geneve's per namespace list */
 };

 static int geneve_net_id;

 static inline __u32 geneve_net_vni_hash(u8 vni[3])
 {
 	__u32 vnid;

 	vnid = (vni[0] << 16) | (vni[1] << 8) | vni[2];
 	return hash_32(vnid, VNI_HASH_BITS);
 }

 /* geneve receive/decap routine */
 static void geneve_rx(struct geneve_sock *gs, struct sk_buff *skb)
 {
 	struct genevehdr *gnvh = geneve_hdr(skb);
 	struct geneve_dev *dummy, *geneve = NULL;
 	struct geneve_net *gn;
 	struct iphdr *iph = NULL;
 	struct pcpu_sw_netstats *stats;
 	struct hlist_head *vni_list_head;
 	int err = 0;
 	__u32 hash;

 	iph = ip_hdr(skb); /* Still outer IP header... */

 	gn = gs->rcv_data;

 	/* Find the device for this VNI */
 	hash = geneve_net_vni_hash(gnvh->vni);
 	vni_list_head = &gn->vni_list[hash];
 	hlist_for_each_entry_rcu(dummy, vni_list_head, hlist) {
 		if (!memcmp(gnvh->vni, dummy->vni, sizeof(dummy->vni)) &&
 		    iph->saddr == dummy->remote.sin_addr.s_addr) {
 			geneve = dummy;
 			break;
 		}
 	}
 	if (!geneve)
 		goto drop;

 	/* Drop packets w/ critical options,
 	 * since we don't support any...
 	 */
 	if (gnvh->critical)
 		goto drop;

 	skb_reset_mac_header(skb);
 	skb_scrub_packet(skb, !net_eq(geneve->net, dev_net(geneve->dev)));
 	skb->protocol = eth_type_trans(skb, geneve->dev);
 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);

 	/* Ignore packet loops (and multicast echo) */
 	if (ether_addr_equal(eth_hdr(skb)->h_source, geneve->dev->dev_addr))
 		goto drop;

 	skb_reset_network_header(skb);

 	iph = ip_hdr(skb); /* Now inner IP header... */
 	err = IP_ECN_decapsulate(iph, skb);

 	if (unlikely(err)) {
 		if (log_ecn_error)
 			net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 					     &iph->saddr, iph->tos);
 		if (err > 1) {
 			++geneve->dev->stats.rx_frame_errors;
 			++geneve->dev->stats.rx_errors;
 			goto drop;
 		}
 	}

 	stats = this_cpu_ptr(geneve->dev->tstats);
 	u64_stats_update_begin(&stats->syncp);
 	stats->rx_packets++;
 	stats->rx_bytes += skb->len;
 	u64_stats_update_end(&stats->syncp);

 	netif_rx(skb);

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

 /* Setup stats when device is created */
 static int geneve_init(struct net_device *dev)
 {
 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 	if (!dev->tstats)
 		return -ENOMEM;

 	return 0;
 }

 static void geneve_uninit(struct net_device *dev)
 {
 	free_percpu(dev->tstats);
 }

 static int geneve_open(struct net_device *dev)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 	struct net *net = geneve->net;
 	struct geneve_net *gn = net_generic(geneve->net, geneve_net_id);
 	struct geneve_sock *gs;

 	gs = geneve_sock_add(net, htons(GENEVE_UDP_PORT), geneve_rx, gn,
 	                     false, false);
 	if (IS_ERR(gs))
 		return PTR_ERR(gs);

 	geneve->sock = gs;

 	return 0;
 }

 static int geneve_stop(struct net_device *dev)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 	struct geneve_sock *gs = geneve->sock;

 	geneve_sock_release(gs);

 	return 0;
 }

 static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 	struct geneve_sock *gs = geneve->sock;
 	struct rtable *rt = NULL;
 	const struct iphdr *iip; /* interior IP header */
 	struct flowi4 fl4;
 	int err;
 	__be16 sport;
 	__u8 tos, ttl;

 	iip = ip_hdr(skb);

 	skb_reset_mac_header(skb);

 	/* TODO: port min/max limits should be configurable */
 	sport = udp_flow_src_port(dev_net(dev), skb, 0, 0, true);

 	tos = geneve->tos;
 	if (tos == 1)
 		tos = ip_tunnel_get_dsfield(iip, skb);

 	memset(&fl4, 0, sizeof(fl4));
 	fl4.flowi4_tos = RT_TOS(tos);
 	fl4.daddr = geneve->remote.sin_addr.s_addr;
 	rt = ip_route_output_key(geneve->net, &fl4);
 	if (IS_ERR(rt)) {
 		netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
 		dev->stats.tx_carrier_errors++;
 		goto tx_error;
 	}
 	if (rt->dst.dev == dev) { /* is this necessary? */
 		netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
 		dev->stats.collisions++;
 		goto rt_tx_error;
 	}

 	tos = ip_tunnel_ecn_encap(tos, iip, skb);

 	ttl = geneve->ttl;
 	if (!ttl && IN_MULTICAST(ntohl(fl4.daddr)))
 		ttl = 1;

 	ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);

 	/* no need to handle local destination and encap bypass...yet... */

 	err = geneve_xmit_skb(gs, rt, skb, fl4.saddr, fl4.daddr,
 	                      tos, ttl, 0, sport, htons(GENEVE_UDP_PORT), 0,
 	                      geneve->vni, 0, NULL, false,
 	                      !net_eq(geneve->net, dev_net(geneve->dev)));
 	if (err < 0)
 		ip_rt_put(rt);

 	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);

 	return NETDEV_TX_OK;

 rt_tx_error:
 	ip_rt_put(rt);
 tx_error:
 	dev->stats.tx_errors++;
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
 }

 static const struct net_device_ops geneve_netdev_ops = {
 	.ndo_init		= geneve_init,
 	.ndo_uninit		= geneve_uninit,
 	.ndo_open		= geneve_open,
 	.ndo_stop		= geneve_stop,
 	.ndo_start_xmit		= geneve_xmit,
 	.ndo_get_stats64	= ip_tunnel_get_stats64,
 	.ndo_change_mtu		= eth_change_mtu,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_set_mac_address	= eth_mac_addr,
 };

 static void geneve_get_drvinfo(struct net_device *dev,
 			       struct ethtool_drvinfo *drvinfo)
 {
 	strlcpy(drvinfo->version, GENEVE_NETDEV_VER, sizeof(drvinfo->version));
 	strlcpy(drvinfo->driver, "geneve", sizeof(drvinfo->driver));
 }

 static const struct ethtool_ops geneve_ethtool_ops = {
 	.get_drvinfo	= geneve_get_drvinfo,
 	.get_link	= ethtool_op_get_link,
 };

 /* Info for udev, that this is a virtual tunnel endpoint */
 static struct device_type geneve_type = {
 	.name = "geneve",
 };

 /* Initialize the device structure. */
 static void geneve_setup(struct net_device *dev)
 {
 	ether_setup(dev);

 	dev->netdev_ops = &geneve_netdev_ops;
 	dev->ethtool_ops = &geneve_ethtool_ops;
 	dev->destructor = free_netdev;

 	SET_NETDEV_DEVTYPE(dev, &geneve_type);

 	dev->tx_queue_len = 0;
 	dev->features    |= NETIF_F_LLTX;
 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
 	dev->features    |= NETIF_F_RXCSUM;
 	dev->features    |= NETIF_F_GSO_SOFTWARE;

 	dev->vlan_features = dev->features;
 	dev->features    |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;

 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;

 	netif_keep_dst(dev);
 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 }

 static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
 	[IFLA_GENEVE_ID]		= { .type = NLA_U32 },
 	[IFLA_GENEVE_REMOTE]		= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
 	[IFLA_GENEVE_TTL]		= { .type = NLA_U8 },
 	[IFLA_GENEVE_TOS]		= { .type = NLA_U8 },
 };

 static int geneve_validate(struct nlattr *tb[], struct nlattr *data[])
 {
 	if (tb[IFLA_ADDRESS]) {
 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 			return -EINVAL;

 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 			return -EADDRNOTAVAIL;
 	}

 	if (!data)
 		return -EINVAL;

 	if (data[IFLA_GENEVE_ID]) {
 		__u32 vni =  nla_get_u32(data[IFLA_GENEVE_ID]);

 		if (vni >= GENEVE_VID_MASK)
 			return -ERANGE;
 	}

 	return 0;
 }

 static int geneve_newlink(struct net *net, struct net_device *dev,
 			 struct nlattr *tb[], struct nlattr *data[])
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_dev *dummy, *geneve = netdev_priv(dev);
 	struct hlist_head *vni_list_head;
 	struct sockaddr_in remote;	/* IPv4 address for link partner */
 	__u32 vni, hash;
 	int err;

 	if (!data[IFLA_GENEVE_ID] || !data[IFLA_GENEVE_REMOTE])
 		return -EINVAL;

 	geneve->net = net;
 	geneve->dev = dev;

 	vni = nla_get_u32(data[IFLA_GENEVE_ID]);
 	geneve->vni[0] = (vni & 0x00ff0000) >> 16;
 	geneve->vni[1] = (vni & 0x0000ff00) >> 8;
 	geneve->vni[2] =  vni & 0x000000ff;

 	geneve->remote.sin_addr.s_addr =
 		nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);
 	if (IN_MULTICAST(ntohl(geneve->remote.sin_addr.s_addr)))
 		return -EINVAL;

 	remote = geneve->remote;
 	hash = geneve_net_vni_hash(geneve->vni);
 	vni_list_head = &gn->vni_list[hash];
 	hlist_for_each_entry_rcu(dummy, vni_list_head, hlist) {
 		if (!memcmp(geneve->vni, dummy->vni, sizeof(dummy->vni)) &&
 		    !memcmp(&remote, &dummy->remote, sizeof(dummy->remote)))
 			return -EBUSY;
 	}

 	if (tb[IFLA_ADDRESS] == NULL)
 		eth_hw_addr_random(dev);

 	err = register_netdevice(dev);
 	if (err)
 		return err;

 	if (data[IFLA_GENEVE_TTL])
 		geneve->ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);

 	if (data[IFLA_GENEVE_TOS])
 		geneve->tos = nla_get_u8(data[IFLA_GENEVE_TOS]);

 	list_add(&geneve->next, &gn->geneve_list);

 	hlist_add_head_rcu(&geneve->hlist, &gn->vni_list[hash]);

 	return 0;
 }

 static void geneve_dellink(struct net_device *dev, struct list_head *head)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);

 	if (!hlist_unhashed(&geneve->hlist))
 		hlist_del_rcu(&geneve->hlist);

 	list_del(&geneve->next);
 	unregister_netdevice_queue(dev, head);
 }

 static size_t geneve_get_size(const struct net_device *dev)
 {
 	return nla_total_size(sizeof(__u32)) +	/* IFLA_GENEVE_ID */
 		nla_total_size(sizeof(struct in_addr)) + /* IFLA_GENEVE_REMOTE */
 		nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TTL */
 		nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TOS */
 		0;
 }

 static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 	__u32 vni;

 	vni = (geneve->vni[0] << 16) | (geneve->vni[1] << 8) | geneve->vni[2];
 	if (nla_put_u32(skb, IFLA_GENEVE_ID, vni))
 		goto nla_put_failure;

 	if (nla_put_in_addr(skb, IFLA_GENEVE_REMOTE,
 			    geneve->remote.sin_addr.s_addr))
 		goto nla_put_failure;

 	if (nla_put_u8(skb, IFLA_GENEVE_TTL, geneve->ttl) ||
 	    nla_put_u8(skb, IFLA_GENEVE_TOS, geneve->tos))
 		goto nla_put_failure;

 	return 0;

 nla_put_failure:
 	return -EMSGSIZE;
 }

 static struct rtnl_link_ops geneve_link_ops __read_mostly = {
 	.kind		= "geneve",
 	.maxtype	= IFLA_GENEVE_MAX,
 	.policy		= geneve_policy,
 	.priv_size	= sizeof(struct geneve_dev),
 	.setup		= geneve_setup,
 	.validate	= geneve_validate,
 	.newlink	= geneve_newlink,
 	.dellink	= geneve_dellink,
 	.get_size	= geneve_get_size,
 	.fill_info	= geneve_fill_info,
 };

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

 	INIT_LIST_HEAD(&gn->geneve_list);

 	for (h = 0; h < VNI_HASH_SIZE; ++h)
 		INIT_HLIST_HEAD(&gn->vni_list[h]);

 	return 0;
 }

 static void __net_exit geneve_exit_net(struct net *net)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_dev *geneve, *next;
 	struct net_device *dev, *aux;
 	LIST_HEAD(list);

 	rtnl_lock();

 	/* gather any geneve devices that were moved into this ns */
 	for_each_netdev_safe(net, dev, aux)
 		if (dev->rtnl_link_ops == &geneve_link_ops)
 			unregister_netdevice_queue(dev, &list);

 	/* now gather any other geneve devices that were created in this ns */
 	list_for_each_entry_safe(geneve, next, &gn->geneve_list, next) {
 		/* If geneve->dev is in the same netns, it was already added
 		 * to the list by the previous loop.
 		 */
 		if (!net_eq(dev_net(geneve->dev), net))
 			unregister_netdevice_queue(geneve->dev, &list);
 	}

 	/* unregister the devices gathered above */
 	unregister_netdevice_many(&list);
 	rtnl_unlock();
 }

 static struct pernet_operations geneve_net_ops = {
 	.init = geneve_init_net,
 	.exit = geneve_exit_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)
 		goto out1;

 	rc = rtnl_link_register(&geneve_link_ops);
 	if (rc)
 		goto out2;

 	return 0;
 out2:
 	unregister_pernet_subsys(&geneve_net_ops);
 out1:
 	return rc;
 }
 late_initcall(geneve_init_module);

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

 MODULE_LICENSE("GPL");
 MODULE_VERSION(GENEVE_NETDEV_VER);
 MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
 MODULE_DESCRIPTION("Interface driver for GENEVE encapsulated traffic");
 MODULE_ALIAS_RTNL_LINK("geneve");
	/*
	* GENEVE: Generic Network Virtualization Encapsulation
	*
	* Copyright (c) 2015 Red Hat, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/hash.h>
	#include <net/rtnetlink.h>
	#include <net/geneve.h>

	#define GENEVE_NETDEV_VER "0.6"

	#define GENEVE_UDP_PORT 6081

	#define GENEVE_N_VID (1u << 24)
	#define GENEVE_VID_MASK (GENEVE_N_VID - 1)

	#define VNI_HASH_BITS 10
	#define VNI_HASH_SIZE (1<<VNI_HASH_BITS)

	static bool log_ecn_error = true;
	module_param(log_ecn_error, bool, 0644);
	MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");

	/* per-network namespace private data for this module */
	struct geneve_net {
	struct list_head geneve_list;
	struct hlist_head vni_list[VNI_HASH_SIZE];
	};

	/* Pseudo network device */
	struct geneve_dev {
	struct hlist_node hlist; /* vni hash table */
	struct net net; / netns for packet i/o */
	struct net_device dev; / netdev for geneve tunnel */
	struct geneve_sock sock; / socket used for geneve tunnel */
	u8 vni[3]; /* virtual network ID for tunnel */
	u8 ttl; /* TTL override */
	u8 tos; /* TOS override */
	struct sockaddr_in remote; /* IPv4 address for link partner */
	struct list_head next; /* geneve's per namespace list */
	};

	static int geneve_net_id;

	static inline __u32 geneve_net_vni_hash(u8 vni[3])
	{
	__u32 vnid;

	vnid = (vni[0] << 16) \| (vni[1] << 8) \| vni[2];
	return hash_32(vnid, VNI_HASH_BITS);
	}

	/* geneve receive/decap routine */
	static void geneve_rx(struct geneve_sock gs, struct sk_buff skb)
	{
	struct genevehdr *gnvh = geneve_hdr(skb);
	struct geneve_dev dummy, geneve = NULL;
	struct geneve_net *gn;
	struct iphdr *iph = NULL;
	struct pcpu_sw_netstats *stats;
	struct hlist_head *vni_list_head;
	int err = 0;
	__u32 hash;

	iph = ip_hdr(skb); /* Still outer IP header... */

	gn = gs->rcv_data;

	/* Find the device for this VNI */
	hash = geneve_net_vni_hash(gnvh->vni);
	vni_list_head = &gn->vni_list[hash];
	hlist_for_each_entry_rcu(dummy, vni_list_head, hlist) {
	if (!memcmp(gnvh->vni, dummy->vni, sizeof(dummy->vni)) &&
	iph->saddr == dummy->remote.sin_addr.s_addr) {
	geneve = dummy;
	break;
	}
	}
	if (!geneve)
	goto drop;

	/* Drop packets w/ critical options,
	* since we don't support any...
	*/
	if (gnvh->critical)
	goto drop;

	skb_reset_mac_header(skb);
	skb_scrub_packet(skb, !net_eq(geneve->net, dev_net(geneve->dev)));
	skb->protocol = eth_type_trans(skb, geneve->dev);
	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);

	/* Ignore packet loops (and multicast echo) */
	if (ether_addr_equal(eth_hdr(skb)->h_source, geneve->dev->dev_addr))
	goto drop;

	skb_reset_network_header(skb);

	iph = ip_hdr(skb); /* Now inner IP header... */
	err = IP_ECN_decapsulate(iph, skb);

	if (unlikely(err)) {
	if (log_ecn_error)
	net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
	&iph->saddr, iph->tos);
	if (err > 1) {
	++geneve->dev->stats.rx_frame_errors;
	++geneve->dev->stats.rx_errors;
	goto drop;
	}
	}

	stats = this_cpu_ptr(geneve->dev->tstats);
	u64_stats_update_begin(&stats->syncp);
	stats->rx_packets++;
	stats->rx_bytes += skb->len;
	u64_stats_update_end(&stats->syncp);

	netif_rx(skb);

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

	/* Setup stats when device is created */
	static int geneve_init(struct net_device *dev)
	{
	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
	if (!dev->tstats)
	return -ENOMEM;

	return 0;
	}

	static void geneve_uninit(struct net_device *dev)
	{
	free_percpu(dev->tstats);
	}

	static int geneve_open(struct net_device *dev)
	{
	struct geneve_dev *geneve = netdev_priv(dev);
	struct net *net = geneve->net;
	struct geneve_net *gn = net_generic(geneve->net, geneve_net_id);
	struct geneve_sock *gs;

	gs = geneve_sock_add(net, htons(GENEVE_UDP_PORT), geneve_rx, gn,
	false, false);
	if (IS_ERR(gs))
	return PTR_ERR(gs);

	geneve->sock = gs;

	return 0;
	}

	static int geneve_stop(struct net_device *dev)
	{
	struct geneve_dev *geneve = netdev_priv(dev);
	struct geneve_sock *gs = geneve->sock;

	geneve_sock_release(gs);

	return 0;
	}

	static netdev_tx_t geneve_xmit(struct sk_buff skb, struct net_device dev)
	{
	struct geneve_dev *geneve = netdev_priv(dev);
	struct geneve_sock *gs = geneve->sock;
	struct rtable *rt = NULL;
	const struct iphdr iip; / interior IP header */
	struct flowi4 fl4;
	int err;
	__be16 sport;
	__u8 tos, ttl;

	iip = ip_hdr(skb);

	skb_reset_mac_header(skb);

	/* TODO: port min/max limits should be configurable */
	sport = udp_flow_src_port(dev_net(dev), skb, 0, 0, true);

	tos = geneve->tos;
	if (tos == 1)
	tos = ip_tunnel_get_dsfield(iip, skb);

	memset(&fl4, 0, sizeof(fl4));
	fl4.flowi4_tos = RT_TOS(tos);
	fl4.daddr = geneve->remote.sin_addr.s_addr;
	rt = ip_route_output_key(geneve->net, &fl4);
	if (IS_ERR(rt)) {
	netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
	dev->stats.tx_carrier_errors++;
	goto tx_error;
	}
	if (rt->dst.dev == dev) { /* is this necessary? */
	netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
	dev->stats.collisions++;
	goto rt_tx_error;
	}

	tos = ip_tunnel_ecn_encap(tos, iip, skb);

	ttl = geneve->ttl;
	if (!ttl && IN_MULTICAST(ntohl(fl4.daddr)))
	ttl = 1;

	ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);

	/* no need to handle local destination and encap bypass...yet... */

	err = geneve_xmit_skb(gs, rt, skb, fl4.saddr, fl4.daddr,
	tos, ttl, 0, sport, htons(GENEVE_UDP_PORT), 0,
	geneve->vni, 0, NULL, false,
	!net_eq(geneve->net, dev_net(geneve->dev)));
	if (err < 0)
	ip_rt_put(rt);

	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);

	return NETDEV_TX_OK;

	rt_tx_error:
	ip_rt_put(rt);
	tx_error:
	dev->stats.tx_errors++;
	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
	}

	static const struct net_device_ops geneve_netdev_ops = {
	.ndo_init = geneve_init,
	.ndo_uninit = geneve_uninit,
	.ndo_open = geneve_open,
	.ndo_stop = geneve_stop,
	.ndo_start_xmit = geneve_xmit,
	.ndo_get_stats64 = ip_tunnel_get_stats64,
	.ndo_change_mtu = eth_change_mtu,
	.ndo_validate_addr = eth_validate_addr,
	.ndo_set_mac_address = eth_mac_addr,
	};

	static void geneve_get_drvinfo(struct net_device *dev,
	struct ethtool_drvinfo *drvinfo)
	{
	strlcpy(drvinfo->version, GENEVE_NETDEV_VER, sizeof(drvinfo->version));
	strlcpy(drvinfo->driver, "geneve", sizeof(drvinfo->driver));
	}

	static const struct ethtool_ops geneve_ethtool_ops = {
	.get_drvinfo = geneve_get_drvinfo,
	.get_link = ethtool_op_get_link,
	};

	/* Info for udev, that this is a virtual tunnel endpoint */
	static struct device_type geneve_type = {
	.name = "geneve",
	};

	/* Initialize the device structure. */
	static void geneve_setup(struct net_device *dev)
	{
	ether_setup(dev);

	dev->netdev_ops = &geneve_netdev_ops;
	dev->ethtool_ops = &geneve_ethtool_ops;
	dev->destructor = free_netdev;

	SET_NETDEV_DEVTYPE(dev, &geneve_type);

	dev->tx_queue_len = 0;
	dev->features \|= NETIF_F_LLTX;
	dev->features \|= NETIF_F_SG \| NETIF_F_HW_CSUM;
	dev->features \|= NETIF_F_RXCSUM;
	dev->features \|= NETIF_F_GSO_SOFTWARE;

	dev->vlan_features = dev->features;
	dev->features \|= NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_STAG_TX;

	dev->hw_features \|= NETIF_F_SG \| NETIF_F_HW_CSUM \| NETIF_F_RXCSUM;
	dev->hw_features \|= NETIF_F_GSO_SOFTWARE;
	dev->hw_features \|= NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_STAG_TX;

	netif_keep_dst(dev);
	dev->priv_flags \|= IFF_LIVE_ADDR_CHANGE;
	}

	static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
	[IFLA_GENEVE_ID] = { .type = NLA_U32 },
	[IFLA_GENEVE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
	[IFLA_GENEVE_TTL] = { .type = NLA_U8 },
	[IFLA_GENEVE_TOS] = { .type = NLA_U8 },
	};

	static int geneve_validate(struct nlattr tb[], struct nlattr data[])
	{
	if (tb[IFLA_ADDRESS]) {
	if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
	return -EINVAL;

	if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
	return -EADDRNOTAVAIL;
	}

	if (!data)
	return -EINVAL;

	if (data[IFLA_GENEVE_ID]) {
	__u32 vni = nla_get_u32(data[IFLA_GENEVE_ID]);

	if (vni >= GENEVE_VID_MASK)
	return -ERANGE;
	}

	return 0;
	}

	static int geneve_newlink(struct net net, struct net_device dev,
	struct nlattr tb[], struct nlattr data[])
	{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_dev dummy, geneve = netdev_priv(dev);
	struct hlist_head *vni_list_head;
	struct sockaddr_in remote; /* IPv4 address for link partner */
	__u32 vni, hash;
	int err;

	if (!data[IFLA_GENEVE_ID] \|\| !data[IFLA_GENEVE_REMOTE])
	return -EINVAL;

	geneve->net = net;
	geneve->dev = dev;

	vni = nla_get_u32(data[IFLA_GENEVE_ID]);
	geneve->vni[0] = (vni & 0x00ff0000) >> 16;
	geneve->vni[1] = (vni & 0x0000ff00) >> 8;
	geneve->vni[2] = vni & 0x000000ff;

	geneve->remote.sin_addr.s_addr =
	nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);
	if (IN_MULTICAST(ntohl(geneve->remote.sin_addr.s_addr)))
	return -EINVAL;

	remote = geneve->remote;
	hash = geneve_net_vni_hash(geneve->vni);
	vni_list_head = &gn->vni_list[hash];
	hlist_for_each_entry_rcu(dummy, vni_list_head, hlist) {
	if (!memcmp(geneve->vni, dummy->vni, sizeof(dummy->vni)) &&
	!memcmp(&remote, &dummy->remote, sizeof(dummy->remote)))
	return -EBUSY;
	}

	if (tb[IFLA_ADDRESS] == NULL)
	eth_hw_addr_random(dev);

	err = register_netdevice(dev);
	if (err)
	return err;

	if (data[IFLA_GENEVE_TTL])
	geneve->ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);

	if (data[IFLA_GENEVE_TOS])
	geneve->tos = nla_get_u8(data[IFLA_GENEVE_TOS]);

	list_add(&geneve->next, &gn->geneve_list);

	hlist_add_head_rcu(&geneve->hlist, &gn->vni_list[hash]);

	return 0;
	}

	static void geneve_dellink(struct net_device dev, struct list_head head)
	{
	struct geneve_dev *geneve = netdev_priv(dev);

	if (!hlist_unhashed(&geneve->hlist))
	hlist_del_rcu(&geneve->hlist);

	list_del(&geneve->next);
	unregister_netdevice_queue(dev, head);
	}

	static size_t geneve_get_size(const struct net_device *dev)
	{
	return nla_total_size(sizeof(__u32)) + /* IFLA_GENEVE_ID */
	nla_total_size(sizeof(struct in_addr)) + /* IFLA_GENEVE_REMOTE */
	nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_TTL */
	nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_TOS */
	0;
	}

	static int geneve_fill_info(struct sk_buff skb, const struct net_device dev)
	{
	struct geneve_dev *geneve = netdev_priv(dev);
	__u32 vni;

	vni = (geneve->vni[0] << 16) \| (geneve->vni[1] << 8) \| geneve->vni[2];
	if (nla_put_u32(skb, IFLA_GENEVE_ID, vni))
	goto nla_put_failure;

	if (nla_put_in_addr(skb, IFLA_GENEVE_REMOTE,
	geneve->remote.sin_addr.s_addr))
	goto nla_put_failure;

	if (nla_put_u8(skb, IFLA_GENEVE_TTL, geneve->ttl) \|\|
	nla_put_u8(skb, IFLA_GENEVE_TOS, geneve->tos))
	goto nla_put_failure;

	return 0;

	nla_put_failure:
	return -EMSGSIZE;
	}

	static struct rtnl_link_ops geneve_link_ops __read_mostly = {
	.kind = "geneve",
	.maxtype = IFLA_GENEVE_MAX,
	.policy = geneve_policy,
	.priv_size = sizeof(struct geneve_dev),
	.setup = geneve_setup,
	.validate = geneve_validate,
	.newlink = geneve_newlink,
	.dellink = geneve_dellink,
	.get_size = geneve_get_size,
	.fill_info = geneve_fill_info,
	};

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

	INIT_LIST_HEAD(&gn->geneve_list);

	for (h = 0; h < VNI_HASH_SIZE; ++h)
	INIT_HLIST_HEAD(&gn->vni_list[h]);

	return 0;
	}

	static void __net_exit geneve_exit_net(struct net *net)
	{
	struct geneve_net *gn = net_generic(net, geneve_net_id);
	struct geneve_dev geneve, next;
	struct net_device dev, aux;
	LIST_HEAD(list);

	rtnl_lock();

	/* gather any geneve devices that were moved into this ns */
	for_each_netdev_safe(net, dev, aux)
	if (dev->rtnl_link_ops == &geneve_link_ops)
	unregister_netdevice_queue(dev, &list);

	/* now gather any other geneve devices that were created in this ns */
	list_for_each_entry_safe(geneve, next, &gn->geneve_list, next) {
	/* If geneve->dev is in the same netns, it was already added
	* to the list by the previous loop.
	*/
	if (!net_eq(dev_net(geneve->dev), net))
	unregister_netdevice_queue(geneve->dev, &list);
	}

	/* unregister the devices gathered above */
	unregister_netdevice_many(&list);
	rtnl_unlock();
	}

	static struct pernet_operations geneve_net_ops = {
	.init = geneve_init_net,
	.exit = geneve_exit_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)
	goto out1;

	rc = rtnl_link_register(&geneve_link_ops);
	if (rc)
	goto out2;

	return 0;
	out2:
	unregister_pernet_subsys(&geneve_net_ops);
	out1:
	return rc;
	}
	late_initcall(geneve_init_module);

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

	MODULE_LICENSE("GPL");
	MODULE_VERSION(GENEVE_NETDEV_VER);
	MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
	MODULE_DESCRIPTION("Interface driver for GENEVE encapsulated traffic");
	MODULE_ALIAS_RTNL_LINK("geneve");