text: /*
   * 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/etherdevice.h>
  #include <linux/hash.h>
  #include <net/dst_metadata.h>
  #include <net/gro_cells.h>
  #include <net/rtnetlink.h>
  #include <net/geneve.h>
  #include <net/protocol.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");
  
  #define GENEVE_VER 0
  #define GENEVE_BASE_HLEN (sizeof(struct udphdr) + sizeof(struct genevehdr))
  
  /* per-network namespace private data for this module */
  struct geneve_net {
  	struct list_head	geneve_list;
  	struct list_head	sock_list;
  };
  
  static int geneve_net_id;
  
  union geneve_addr {
  	struct sockaddr_in sin;
  	struct sockaddr_in6 sin6;
  	struct sockaddr sa;
  };
  
  static union geneve_addr geneve_remote_unspec = { .sa.sa_family = AF_UNSPEC, };
  
  /* 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 __rcu *sock4;	/* IPv4 socket used for geneve tunnel */
  #if IS_ENABLED(CONFIG_IPV6)
  	struct geneve_sock __rcu *sock6;	/* IPv6 socket used for geneve tunnel */
  #endif
  	u8                 vni[3];	/* virtual network ID for tunnel */
  	u8                 ttl;		/* TTL override */
  	u8                 tos;		/* TOS override */
  	union geneve_addr  remote;	/* IP address for link partner */
  	struct list_head   next;	/* geneve's per namespace list */
  	__be32		   label;	/* IPv6 flowlabel override */
  	__be16		   dst_port;
  	bool		   collect_md;
  	struct gro_cells   gro_cells;
  	u32		   flags;
  	struct dst_cache   dst_cache;
  };
  
  /* Geneve device flags */
  #define GENEVE_F_UDP_ZERO_CSUM_TX	BIT(0)
  #define GENEVE_F_UDP_ZERO_CSUM6_TX	BIT(1)
  #define GENEVE_F_UDP_ZERO_CSUM6_RX	BIT(2)
  
  struct geneve_sock {
  	bool			collect_md;
  	struct list_head	list;
  	struct socket		*sock;
  	struct rcu_head		rcu;
  	int			refcnt;
  	struct hlist_head	vni_list[VNI_HASH_SIZE];
  	u32			flags;
  };
  
  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);
  }
  
  static __be64 vni_to_tunnel_id(const __u8 *vni)
  {
  #ifdef __BIG_ENDIAN
  	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
  #else
  	return (__force __be64)(((__force u64)vni[0] << 40) |
  				((__force u64)vni[1] << 48) |
  				((__force u64)vni[2] << 56));
  #endif
  }
  
  static sa_family_t geneve_get_sk_family(struct geneve_sock *gs)
  {
  	return gs->sock->sk->sk_family;
  }
  
  static struct geneve_dev *geneve_lookup(struct geneve_sock *gs,
  					__be32 addr, u8 vni[])
  {
  	struct hlist_head *vni_list_head;
  	struct geneve_dev *geneve;
  	__u32 hash;
  
  	/* Find the device for this VNI */
  	hash = geneve_net_vni_hash(vni);
  	vni_list_head = &gs->vni_list[hash];
  	hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
  		if (!memcmp(vni, geneve->vni, sizeof(geneve->vni)) &&
  		    addr == geneve->remote.sin.sin_addr.s_addr)
  			return geneve;
  	}
  	return NULL;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static struct geneve_dev *geneve6_lookup(struct geneve_sock *gs,
  					 struct in6_addr addr6, u8 vni[])
  {
  	struct hlist_head *vni_list_head;
  	struct geneve_dev *geneve;
  	__u32 hash;
  
  	/* Find the device for this VNI */
  	hash = geneve_net_vni_hash(vni);
  	vni_list_head = &gs->vni_list[hash];
  	hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
  		if (!memcmp(vni, geneve->vni, sizeof(geneve->vni)) &&
  		    ipv6_addr_equal(&addr6, &geneve->remote.sin6.sin6_addr))
  			return geneve;
  	}
  	return NULL;
  }
  #endif
  
  static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
  {
  	return (struct genevehdr *)(udp_hdr(skb) + 1);
  }
  
  static struct geneve_dev *geneve_lookup_skb(struct geneve_sock *gs,
  					    struct sk_buff *skb)
  {
  	u8 *vni;
  	__be32 addr;
  	static u8 zero_vni[3];
  #if IS_ENABLED(CONFIG_IPV6)
  	static struct in6_addr zero_addr6;
  #endif
  
  	if (geneve_get_sk_family(gs) == AF_INET) {
  		struct iphdr *iph;
  
  		iph = ip_hdr(skb); /* outer IP header... */
  
  		if (gs->collect_md) {
  			vni = zero_vni;
  			addr = 0;
  		} else {
  			vni = geneve_hdr(skb)->vni;
  			addr = iph->saddr;
  		}
  
  		return geneve_lookup(gs, addr, vni);
  #if IS_ENABLED(CONFIG_IPV6)
  	} else if (geneve_get_sk_family(gs) == AF_INET6) {
  		struct ipv6hdr *ip6h;
  		struct in6_addr addr6;
  
  		ip6h = ipv6_hdr(skb); /* outer IPv6 header... */
  
  		if (gs->collect_md) {
  			vni = zero_vni;
  			addr6 = zero_addr6;
  		} else {
  			vni = geneve_hdr(skb)->vni;
  			addr6 = ip6h->saddr;
  		}
  
  		return geneve6_lookup(gs, addr6, vni);
  #endif
  	}
  	return NULL;
  }
  
  /* geneve receive/decap routine */
  static void geneve_rx(struct geneve_dev *geneve, struct geneve_sock *gs,
  		      struct sk_buff *skb)
  {
  	struct genevehdr *gnvh = geneve_hdr(skb);
  	struct metadata_dst *tun_dst = NULL;
  	struct pcpu_sw_netstats *stats;
  	unsigned int len;
  	int err = 0;
  	void *oiph;
  
  	if (ip_tunnel_collect_metadata() || gs->collect_md) {
  		__be16 flags;
  
  		flags = TUNNEL_KEY | TUNNEL_GENEVE_OPT |
  			(gnvh->oam ? TUNNEL_OAM : 0) |
  			(gnvh->critical ? TUNNEL_CRIT_OPT : 0);
  
  		tun_dst = udp_tun_rx_dst(skb, geneve_get_sk_family(gs), flags,
  					 vni_to_tunnel_id(gnvh->vni),
  					 gnvh->opt_len * 4);
  		if (!tun_dst) {
  			geneve->dev->stats.rx_dropped++;
  			goto drop;
  		}
  		/* Update tunnel dst according to Geneve options. */
  		ip_tunnel_info_opts_set(&tun_dst->u.tun_info,
  					gnvh->options, gnvh->opt_len * 4);
  	} else {
  		/* Drop packets w/ critical options,
  		 * since we don't support any...
  		 */
  		if (gnvh->critical) {
  			geneve->dev->stats.rx_frame_errors++;
  			geneve->dev->stats.rx_errors++;
  			goto drop;
  		}
  	}
  
  	skb_reset_mac_header(skb);
  	skb->protocol = eth_type_trans(skb, geneve->dev);
  	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
  
  	if (tun_dst)
  		skb_dst_set(skb, &tun_dst->dst);
  
  	/* Ignore packet loops (and multicast echo) */
  	if (ether_addr_equal(eth_hdr(skb)->h_source, geneve->dev->dev_addr)) {
  		geneve->dev->stats.rx_errors++;
  		goto drop;
  	}
  
  	oiph = skb_network_header(skb);
  	skb_reset_network_header(skb);
  
  	if (geneve_get_sk_family(gs) == AF_INET)
  		err = IP_ECN_decapsulate(oiph, skb);
  #if IS_ENABLED(CONFIG_IPV6)
  	else
  		err = IP6_ECN_decapsulate(oiph, skb);
  #endif
  
  	if (unlikely(err)) {
  		if (log_ecn_error) {
  			if (geneve_get_sk_family(gs) == AF_INET)
  				net_info_ratelimited("non-ECT from %pI4 "
  						     "with TOS=%#x\n",
  						     &((struct iphdr *)oiph)->saddr,
  						     ((struct iphdr *)oiph)->tos);
  #if IS_ENABLED(CONFIG_IPV6)
  			else
  				net_info_ratelimited("non-ECT from %pI6\n",
  						     &((struct ipv6hdr *)oiph)->saddr);
  #endif
  		}
  		if (err > 1) {
  			++geneve->dev->stats.rx_frame_errors;
  			++geneve->dev->stats.rx_errors;
  			goto drop;
  		}
  	}
  
  	len = skb->len;
  	err = gro_cells_receive(&geneve->gro_cells, skb);
  	if (likely(err == NET_RX_SUCCESS)) {
  		stats = this_cpu_ptr(geneve->dev->tstats);
  		u64_stats_update_begin(&stats->syncp);
  		stats->rx_packets++;
  		stats->rx_bytes += len;
  		u64_stats_update_end(&stats->syncp);
  	}
  	return;
  drop:
  	/* Consume bad packet */
  	kfree_skb(skb);
  }
  
  /* Setup stats when device is created */
  static int geneve_init(struct net_device *dev)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	int err;
  
  	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
  	if (!dev->tstats)
  		return -ENOMEM;
  
  	err = gro_cells_init(&geneve->gro_cells, dev);
  	if (err) {
  		free_percpu(dev->tstats);
  		return err;
  	}
  
  	err = dst_cache_init(&geneve->dst_cache, GFP_KERNEL);
  	if (err) {
  		free_percpu(dev->tstats);
  		gro_cells_destroy(&geneve->gro_cells);
  		return err;
  	}
  
  	return 0;
  }
  
  static void geneve_uninit(struct net_device *dev)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  
  	dst_cache_destroy(&geneve->dst_cache);
  	gro_cells_destroy(&geneve->gro_cells);
  	free_percpu(dev->tstats);
  }
  
  /* 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_dev *geneve;
  	struct geneve_sock *gs;
  	int opts_len;
  
  	/* Need UDP and Geneve header to be present */
  	if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
  		goto drop;
  
  	/* Return packets with reserved bits set */
  	geneveh = geneve_hdr(skb);
  	if (unlikely(geneveh->ver != GENEVE_VER))
  		goto drop;
  
  	if (unlikely(geneveh->proto_type != htons(ETH_P_TEB)))
  		goto drop;
  
  	gs = rcu_dereference_sk_user_data(sk);
  	if (!gs)
  		goto drop;
  
  	geneve = geneve_lookup_skb(gs, skb);
  	if (!geneve)
  		goto drop;
  
  	opts_len = geneveh->opt_len * 4;
  	if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len,
  				 htons(ETH_P_TEB),
  				 !net_eq(geneve->net, dev_net(geneve->dev)))) {
  		geneve->dev->stats.rx_dropped++;
  		goto drop;
  	}
  
  	geneve_rx(geneve, gs, skb);
  	return 0;
  
  drop:
  	/* Consume bad packet */
  	kfree_skb(skb);
  	return 0;
  }
  
  static struct socket *geneve_create_sock(struct net *net, bool ipv6,
  					 __be16 port, u32 flags)
  {
  	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;
  		udp_conf.ipv6_v6only = 1;
  		udp_conf.use_udp6_rx_checksums =
  		    !(flags & GENEVE_F_UDP_ZERO_CSUM6_RX);
  	} 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;
  }
  
  static int geneve_hlen(struct genevehdr *gh)
  {
  	return sizeof(*gh) + gh->opt_len * 4;
  }
  
  static struct sk_buff **geneve_gro_receive(struct sock *sk,
  					   struct sk_buff **head,
  					   struct sk_buff *skb)
  {
  	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;
  	}
  
  	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)
  		goto out_unlock;
  
  	skb_gro_pull(skb, gh_len);
  	skb_gro_postpull_rcsum(skb, gh, gh_len);
  	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
  	flush = 0;
  
  out_unlock:
  	rcu_read_unlock();
  out:
  	NAPI_GRO_CB(skb)->flush |= flush;
  
  	return pp;
  }
  
  static int geneve_gro_complete(struct sock *sk, struct sk_buff *skb,
  			       int nhoff)
  {
  	struct genevehdr *gh;
  	struct packet_offload *ptype;
  	__be16 type;
  	int gh_len;
  	int err = -ENOSYS;
  
  	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();
  
  	skb_set_inner_mac_header(skb, nhoff + gh_len);
  
  	return err;
  }
  
  /* Create new listen socket if needed */
  static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
  						bool ipv6, u32 flags)
  {
  	struct geneve_net *gn = net_generic(net, geneve_net_id);
  	struct geneve_sock *gs;
  	struct socket *sock;
  	struct udp_tunnel_sock_cfg tunnel_cfg;
  	int h;
  
  	gs = kzalloc(sizeof(*gs), GFP_KERNEL);
  	if (!gs)
  		return ERR_PTR(-ENOMEM);
  
  	sock = geneve_create_sock(net, ipv6, port, flags);
  	if (IS_ERR(sock)) {
  		kfree(gs);
  		return ERR_CAST(sock);
  	}
  
  	gs->sock = sock;
  	gs->refcnt = 1;
  	for (h = 0; h < VNI_HASH_SIZE; ++h)
  		INIT_HLIST_HEAD(&gs->vni_list[h]);
  
  	/* Initialize the geneve udp offloads structure */
  	udp_tunnel_notify_add_rx_port(gs->sock, UDP_TUNNEL_TYPE_GENEVE);
  
  	/* Mark socket as an encapsulation socket */
  	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
  	tunnel_cfg.sk_user_data = gs;
  	tunnel_cfg.encap_type = 1;
  	tunnel_cfg.gro_receive = geneve_gro_receive;
  	tunnel_cfg.gro_complete = geneve_gro_complete;
  	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;
  }
  
  static void __geneve_sock_release(struct geneve_sock *gs)
  {
  	if (!gs || --gs->refcnt)
  		return;
  
  	list_del(&gs->list);
  	udp_tunnel_notify_del_rx_port(gs->sock, UDP_TUNNEL_TYPE_GENEVE);
  	udp_tunnel_sock_release(gs->sock);
  	kfree_rcu(gs, rcu);
  }
  
  static void geneve_sock_release(struct geneve_dev *geneve)
  {
  	struct geneve_sock *gs4 = rtnl_dereference(geneve->sock4);
  #if IS_ENABLED(CONFIG_IPV6)
  	struct geneve_sock *gs6 = rtnl_dereference(geneve->sock6);
  
  	rcu_assign_pointer(geneve->sock6, NULL);
  #endif
  
  	rcu_assign_pointer(geneve->sock4, NULL);
  	synchronize_net();
  
  	__geneve_sock_release(gs4);
  #if IS_ENABLED(CONFIG_IPV6)
  	__geneve_sock_release(gs6);
  #endif
  }
  
  static struct geneve_sock *geneve_find_sock(struct geneve_net *gn,
  					    sa_family_t family,
  					    __be16 dst_port)
  {
  	struct geneve_sock *gs;
  
  	list_for_each_entry(gs, &gn->sock_list, list) {
  		if (inet_sk(gs->sock->sk)->inet_sport == dst_port &&
  		    geneve_get_sk_family(gs) == family) {
  			return gs;
  		}
  	}
  	return NULL;
  }
  
  static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
  {
  	struct net *net = geneve->net;
  	struct geneve_net *gn = net_generic(net, geneve_net_id);
  	struct geneve_sock *gs;
  	__u32 hash;
  
  	gs = geneve_find_sock(gn, ipv6 ? AF_INET6 : AF_INET, geneve->dst_port);
  	if (gs) {
  		gs->refcnt++;
  		goto out;
  	}
  
  	gs = geneve_socket_create(net, geneve->dst_port, ipv6, geneve->flags);
  	if (IS_ERR(gs))
  		return PTR_ERR(gs);
  
  out:
  	gs->collect_md = geneve->collect_md;
  	gs->flags = geneve->flags;
  #if IS_ENABLED(CONFIG_IPV6)
  	if (ipv6)
  		rcu_assign_pointer(geneve->sock6, gs);
  	else
  #endif
  		rcu_assign_pointer(geneve->sock4, gs);
  
  	hash = geneve_net_vni_hash(geneve->vni);
  	hlist_add_head_rcu(&geneve->hlist, &gs->vni_list[hash]);
  	return 0;
  }
  
  static int geneve_open(struct net_device *dev)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	bool ipv6 = geneve->remote.sa.sa_family == AF_INET6;
  	bool metadata = geneve->collect_md;
  	int ret = 0;
  
  #if IS_ENABLED(CONFIG_IPV6)
  	if (ipv6 || metadata)
  		ret = geneve_sock_add(geneve, true);
  #endif
  	if (!ret && (!ipv6 || metadata))
  		ret = geneve_sock_add(geneve, false);
  	if (ret < 0)
  		geneve_sock_release(geneve);
  
  	return ret;
  }
  
  static int geneve_stop(struct net_device *dev)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  
  	if (!hlist_unhashed(&geneve->hlist))
  		hlist_del_rcu(&geneve->hlist);
  	geneve_sock_release(geneve);
  	return 0;
  }
  
  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);
  }
  
  static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
  			    __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
  			    u32 flags, bool xnet)
  {
  	struct genevehdr *gnvh;
  	int min_headroom;
  	int err;
  	bool udp_sum = !(flags & GENEVE_F_UDP_ZERO_CSUM_TX);
  
  	skb_scrub_packet(skb, xnet);
  
  	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
  			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct iphdr);
  	err = skb_cow_head(skb, min_headroom);
  	if (unlikely(err))
  		goto free_rt;
  
  	err = udp_tunnel_handle_offloads(skb, udp_sum);
  	if (err)
  		goto free_rt;
  
  	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 0;
  
  free_rt:
  	ip_rt_put(rt);
  	return err;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
  			     __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
  			     u32 flags, bool xnet)
  {
  	struct genevehdr *gnvh;
  	int min_headroom;
  	int err;
  	bool udp_sum = !(flags & GENEVE_F_UDP_ZERO_CSUM6_TX);
  
  	skb_scrub_packet(skb, xnet);
  
  	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len
  			+ GENEVE_BASE_HLEN + opt_len + sizeof(struct ipv6hdr);
  	err = skb_cow_head(skb, min_headroom);
  	if (unlikely(err))
  		goto free_dst;
  
  	err = udp_tunnel_handle_offloads(skb, udp_sum);
  	if (err)
  		goto free_dst;
  
  	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 0;
  
  free_dst:
  	dst_release(dst);
  	return err;
  }
  #endif
  
  static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
  				       struct net_device *dev,
  				       struct flowi4 *fl4,
  				       struct ip_tunnel_info *info)
  {
  	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct dst_cache *dst_cache;
  	struct rtable *rt = NULL;
  	__u8 tos;
  
  	if (!rcu_dereference(geneve->sock4))
  		return ERR_PTR(-EIO);
  
  	memset(fl4, 0, sizeof(*fl4));
  	fl4->flowi4_mark = skb->mark;
  	fl4->flowi4_proto = IPPROTO_UDP;
  
  	if (info) {
  		fl4->daddr = info->key.u.ipv4.dst;
  		fl4->saddr = info->key.u.ipv4.src;
  		fl4->flowi4_tos = RT_TOS(info->key.tos);
  		dst_cache = &info->dst_cache;
  	} else {
  		tos = geneve->tos;
  		if (tos == 1) {
  			const struct iphdr *iip = ip_hdr(skb);
  
  			tos = ip_tunnel_get_dsfield(iip, skb);
  			use_cache = false;
  		}
  
  		fl4->flowi4_tos = RT_TOS(tos);
  		fl4->daddr = geneve->remote.sin.sin_addr.s_addr;
  		dst_cache = &geneve->dst_cache;
  	}
  
  	if (use_cache) {
  		rt = dst_cache_get_ip4(dst_cache, &fl4->saddr);
  		if (rt)
  			return rt;
  	}
  
  	rt = ip_route_output_key(geneve->net, fl4);
  	if (IS_ERR(rt)) {
  		netdev_dbg(dev, "no route to %pI4\n", &fl4->daddr);
  		return ERR_PTR(-ENETUNREACH);
  	}
  	if (rt->dst.dev == dev) { /* is this necessary? */
  		netdev_dbg(dev, "circular route to %pI4\n", &fl4->daddr);
  		ip_rt_put(rt);
  		return ERR_PTR(-ELOOP);
  	}
  	if (use_cache)
  		dst_cache_set_ip4(dst_cache, &rt->dst, fl4->saddr);
  	return rt;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
  					   struct net_device *dev,
  					   struct flowi6 *fl6,
  					   struct ip_tunnel_info *info)
  {
  	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct dst_entry *dst = NULL;
  	struct dst_cache *dst_cache;
  	struct geneve_sock *gs6;
  	__u8 prio;
  
  	gs6 = rcu_dereference(geneve->sock6);
  	if (!gs6)
  		return ERR_PTR(-EIO);
  
  	memset(fl6, 0, sizeof(*fl6));
  	fl6->flowi6_mark = skb->mark;
  	fl6->flowi6_proto = IPPROTO_UDP;
  
  	if (info) {
  		fl6->daddr = info->key.u.ipv6.dst;
  		fl6->saddr = info->key.u.ipv6.src;
  		fl6->flowlabel = ip6_make_flowinfo(RT_TOS(info->key.tos),
  						   info->key.label);
  		dst_cache = &info->dst_cache;
  	} else {
  		prio = geneve->tos;
  		if (prio == 1) {
  			const struct iphdr *iip = ip_hdr(skb);
  
  			prio = ip_tunnel_get_dsfield(iip, skb);
  			use_cache = false;
  		}
  
  		fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
  						   geneve->label);
  		fl6->daddr = geneve->remote.sin6.sin6_addr;
  		dst_cache = &geneve->dst_cache;
  	}
  
  	if (use_cache) {
  		dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
  		if (dst)
  			return dst;
  	}
  
  	dst = ipv6_stub->ipv6_dst_lookup_flow(geneve->net, gs6->sock->sk, fl6,
  					      NULL);
  	if (IS_ERR(dst)) {
  		netdev_dbg(dev, "no route to %pI6\n", &fl6->daddr);
  		return ERR_PTR(-ENETUNREACH);
  	}
  	if (dst->dev == dev) { /* is this necessary? */
  		netdev_dbg(dev, "circular route to %pI6\n", &fl6->daddr);
  		dst_release(dst);
  		return ERR_PTR(-ELOOP);
  	}
  
  	if (use_cache)
  		dst_cache_set_ip6(dst_cache, dst, &fl6->saddr);
  	return dst;
  }
  #endif
  
  /* Convert 64 bit tunnel ID to 24 bit VNI. */
  static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
  {
  #ifdef __BIG_ENDIAN
  	vni[0] = (__force __u8)(tun_id >> 16);
  	vni[1] = (__force __u8)(tun_id >> 8);
  	vni[2] = (__force __u8)tun_id;
  #else
  	vni[0] = (__force __u8)((__force u64)tun_id >> 40);
  	vni[1] = (__force __u8)((__force u64)tun_id >> 48);
  	vni[2] = (__force __u8)((__force u64)tun_id >> 56);
  #endif
  }
  
  static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
  				   struct ip_tunnel_info *info)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct geneve_sock *gs4;
  	struct rtable *rt = NULL;
  	int err = -EINVAL;
  	struct flowi4 fl4;
  	__u8 tos, ttl;
  	__be16 sport;
  	__be16 df;
  	bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
  	u32 flags = geneve->flags;
  
  	gs4 = rcu_dereference(geneve->sock4);
  	if (!gs4)
  		goto tx_error;
  
  	if (geneve->collect_md) {
  		if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
  			netdev_dbg(dev, "no tunnel metadata\n");
  			goto tx_error;
  		}
  		if (info && ip_tunnel_info_af(info) != AF_INET)
  			goto tx_error;
  	}
  
  	rt = geneve_get_v4_rt(skb, dev, &fl4, info);
  	if (IS_ERR(rt)) {
  		err = PTR_ERR(rt);
  		goto tx_error;
  	}
  
  	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
  	skb_reset_mac_header(skb);
  
  	if (info) {
  		const struct ip_tunnel_key *key = &info->key;
  		u8 *opts = NULL;
  		u8 vni[3];
  
  		tunnel_id_to_vni(key->tun_id, vni);
  		if (info->options_len)
  			opts = ip_tunnel_info_opts(info);
  
  		if (key->tun_flags & TUNNEL_CSUM)
  			flags &= ~GENEVE_F_UDP_ZERO_CSUM_TX;
  		else
  			flags |= GENEVE_F_UDP_ZERO_CSUM_TX;
  
  		err = geneve_build_skb(rt, skb, key->tun_flags, vni,
  				       info->options_len, opts, flags, xnet);
  		if (unlikely(err))
  			goto tx_error;
  
  		tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
  		ttl = key->ttl;
  		df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
  	} else {
  		err = geneve_build_skb(rt, skb, 0, geneve->vni,
  				       0, NULL, flags, xnet);
  		if (unlikely(err))
  			goto tx_error;
  
  		tos = ip_tunnel_ecn_encap(fl4.flowi4_tos, ip_hdr(skb), skb);
  		ttl = geneve->ttl;
  		if (!ttl && IN_MULTICAST(ntohl(fl4.daddr)))
  			ttl = 1;
  		ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
  		df = 0;
  	}
  	udp_tunnel_xmit_skb(rt, gs4->sock->sk, skb, fl4.saddr, fl4.daddr,
  			    tos, ttl, df, sport, geneve->dst_port,
  			    !net_eq(geneve->net, dev_net(geneve->dev)),
  			    !!(flags & GENEVE_F_UDP_ZERO_CSUM_TX));
  
  	return NETDEV_TX_OK;
  
  tx_error:
  	dev_kfree_skb(skb);
  
  	if (err == -ELOOP)
  		dev->stats.collisions++;
  	else if (err == -ENETUNREACH)
  		dev->stats.tx_carrier_errors++;
  
  	dev->stats.tx_errors++;
  	return NETDEV_TX_OK;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
  				    struct ip_tunnel_info *info)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct dst_entry *dst = NULL;
  	struct geneve_sock *gs6;
  	int err = -EINVAL;
  	struct flowi6 fl6;
  	__u8 prio, ttl;
  	__be16 sport;
  	__be32 label;
  	bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
  	u32 flags = geneve->flags;
  
  	gs6 = rcu_dereference(geneve->sock6);
  	if (!gs6)
  		goto tx_error;
  
  	if (geneve->collect_md) {
  		if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
  			netdev_dbg(dev, "no tunnel metadata\n");
  			goto tx_error;
  		}
  	}
  
  	dst = geneve_get_v6_dst(skb, dev, &fl6, info);
  	if (IS_ERR(dst)) {
  		err = PTR_ERR(dst);
  		goto tx_error;
  	}
  
  	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
  	skb_reset_mac_header(skb);
  
  	if (info) {
  		const struct ip_tunnel_key *key = &info->key;
  		u8 *opts = NULL;
  		u8 vni[3];
  
  		tunnel_id_to_vni(key->tun_id, vni);
  		if (info->options_len)
  			opts = ip_tunnel_info_opts(info);
  
  		if (key->tun_flags & TUNNEL_CSUM)
  			flags &= ~GENEVE_F_UDP_ZERO_CSUM6_TX;
  		else
  			flags |= GENEVE_F_UDP_ZERO_CSUM6_TX;
  
  		err = geneve6_build_skb(dst, skb, key->tun_flags, vni,
  					info->options_len, opts,
  					flags, xnet);
  		if (unlikely(err))
  			goto tx_error;
  
  		prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
  		ttl = key->ttl;
  		label = info->key.label;
  	} else {
  		err = geneve6_build_skb(dst, skb, 0, geneve->vni,
  					0, NULL, flags, xnet);
  		if (unlikely(err))
  			goto tx_error;
  
  		prio = ip_tunnel_ecn_encap(ip6_tclass(fl6.flowlabel),
  					   ip_hdr(skb), skb);
  		ttl = geneve->ttl;
  		if (!ttl && ipv6_addr_is_multicast(&fl6.daddr))
  			ttl = 1;
  		ttl = ttl ? : ip6_dst_hoplimit(dst);
  		label = geneve->label;
  	}
  
  	udp_tunnel6_xmit_skb(dst, gs6->sock->sk, skb, dev,
  			     &fl6.saddr, &fl6.daddr, prio, ttl, label,
  			     sport, geneve->dst_port,
  			     !!(flags & GENEVE_F_UDP_ZERO_CSUM6_TX));
  	return NETDEV_TX_OK;
  
  tx_error:
  	dev_kfree_skb(skb);
  
  	if (err == -ELOOP)
  		dev->stats.collisions++;
  	else if (err == -ENETUNREACH)
  		dev->stats.tx_carrier_errors++;
  
  	dev->stats.tx_errors++;
  	return NETDEV_TX_OK;
  }
  #endif
  
  static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct ip_tunnel_info *info = NULL;
  	int err;
  
  	if (geneve->collect_md)
  		info = skb_tunnel_info(skb);
  
  	rcu_read_lock();
  #if IS_ENABLED(CONFIG_IPV6)
  	if ((info && ip_tunnel_info_af(info) == AF_INET6) ||
  	    (!info && geneve->remote.sa.sa_family == AF_INET6))
  		err = geneve6_xmit_skb(skb, dev, info);
  	else
  #endif
  		err = geneve_xmit_skb(skb, dev, info);
  	rcu_read_unlock();
  
  	return err;
  }
  
  static int __geneve_change_mtu(struct net_device *dev, int new_mtu, bool strict)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  	/* The max_mtu calculation does not take account of GENEVE
  	 * options, to avoid excluding potentially valid
  	 * configurations.
  	 */
  	int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;
  
  	if (geneve->remote.sa.sa_family == AF_INET6)
  		max_mtu -= sizeof(struct ipv6hdr);
  	else
  		max_mtu -= sizeof(struct iphdr);
  
  	if (new_mtu < 68)
  		return -EINVAL;
  
  	if (new_mtu > max_mtu) {
  		if (strict)
  			return -EINVAL;
  
  		new_mtu = max_mtu;
  	}
  
  	dev->mtu = new_mtu;
  	return 0;
  }
  
  static int geneve_change_mtu(struct net_device *dev, int new_mtu)
  {
  	return __geneve_change_mtu(dev, new_mtu, true);
  }
  
  static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
  {
  	struct ip_tunnel_info *info = skb_tunnel_info(skb);
  	struct geneve_dev *geneve = netdev_priv(dev);
  	struct rtable *rt;
  	struct flowi4 fl4;
  #if IS_ENABLED(CONFIG_IPV6)
  	struct dst_entry *dst;
  	struct flowi6 fl6;
  #endif
  
  	if (ip_tunnel_info_af(info) == AF_INET) {
  		rt = geneve_get_v4_rt(skb, dev, &fl4, info);
  		if (IS_ERR(rt))
  			return PTR_ERR(rt);
  
  		ip_rt_put(rt);
  		info->key.u.ipv4.src = fl4.saddr;
  #if IS_ENABLED(CONFIG_IPV6)
  	} else if (ip_tunnel_info_af(info) == AF_INET6) {
  		dst = geneve_get_v6_dst(skb, dev, &fl6, info);
  		if (IS_ERR(dst))
  			return PTR_ERR(dst);
  
  		dst_release(dst);
  		info->key.u.ipv6.src = fl6.saddr;
  #endif
  	} else {
  		return -EINVAL;
  	}
  
  	info->key.tp_src = udp_flow_src_port(geneve->net, skb,
  					     1, USHRT_MAX, true);
  	info->key.tp_dst = geneve->dst_port;
  	return 0;
  }
  
  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		= geneve_change_mtu,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_set_mac_address	= eth_mac_addr,
  	.ndo_fill_metadata_dst	= geneve_fill_metadata_dst,
  };
  
  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",
  };
  
  /* Calls the ndo_udp_tunnel_add of the caller in order to
   * supply the listening GENEVE udp ports. Callers are expected
   * to implement the ndo_udp_tunnel_add.
   */
  static void geneve_push_rx_ports(struct net_device *dev)
  {
  	struct net *net = dev_net(dev);
  	struct geneve_net *gn = net_generic(net, geneve_net_id);
  	struct geneve_sock *gs;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(gs, &gn->sock_list, list)
  		udp_tunnel_push_rx_port(dev, gs->sock,
  					UDP_TUNNEL_TYPE_GENEVE);
  	rcu_read_unlock();
  }
  
  /* 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->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->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
  	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
  
  	netif_keep_dst(dev);
  	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
  	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
  	eth_hw_addr_random(dev);
  }
  
  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_REMOTE6]		= { .len = sizeof(struct in6_addr) },
  	[IFLA_GENEVE_TTL]		= { .type = NLA_U8 },
  	[IFLA_GENEVE_TOS]		= { .type = NLA_U8 },
  	[IFLA_GENEVE_LABEL]		= { .type = NLA_U32 },
  	[IFLA_GENEVE_PORT]		= { .type = NLA_U16 },
  	[IFLA_GENEVE_COLLECT_METADATA]	= { .type = NLA_FLAG },
  	[IFLA_GENEVE_UDP_CSUM]		= { .type = NLA_U8 },
  	[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]	= { .type = NLA_U8 },
  	[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]	= { .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 struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
  					  __be16 dst_port,
  					  union geneve_addr *remote,
  					  u8 vni[],
  					  bool *tun_on_same_port,
  					  bool *tun_collect_md)
  {
  	struct geneve_dev *geneve, *t;
  
  	*tun_on_same_port = false;
  	*tun_collect_md = false;
  	t = NULL;
  	list_for_each_entry(geneve, &gn->geneve_list, next) {
  		if (geneve->dst_port == dst_port) {
  			*tun_collect_md = geneve->collect_md;
  			*tun_on_same_port = true;
  		}
  		if (!memcmp(vni, geneve->vni, sizeof(geneve->vni)) &&
  		    !memcmp(remote, &geneve->remote, sizeof(geneve->remote)) &&
  		    dst_port == geneve->dst_port)
  			t = geneve;
  	}
  	return t;
  }
  
  static int geneve_configure(struct net *net, struct net_device *dev,
  			    union geneve_addr *remote,
  			    __u32 vni, __u8 ttl, __u8 tos, __be32 label,
  			    __be16 dst_port, bool metadata, u32 flags)
  {
  	struct geneve_net *gn = net_generic(net, geneve_net_id);
  	struct geneve_dev *t, *geneve = netdev_priv(dev);
  	bool tun_collect_md, tun_on_same_port;
  	int err, encap_len;
  
  	if (!remote)
  		return -EINVAL;
  	if (metadata &&
  	    (remote->sa.sa_family != AF_UNSPEC || vni || tos || ttl || label))
  		return -EINVAL;
  
  	geneve->net = net;
  	geneve->dev = dev;
  
  	geneve->vni[0] = (vni & 0x00ff0000) >> 16;
  	geneve->vni[1] = (vni & 0x0000ff00) >> 8;
  	geneve->vni[2] =  vni & 0x000000ff;
  
  	if ((remote->sa.sa_family == AF_INET &&
  	     IN_MULTICAST(ntohl(remote->sin.sin_addr.s_addr))) ||
  	    (remote->sa.sa_family == AF_INET6 &&
  	     ipv6_addr_is_multicast(&remote->sin6.sin6_addr)))
  		return -EINVAL;
  	if (label && remote->sa.sa_family != AF_INET6)
  		return -EINVAL;
  
  	geneve->remote = *remote;
  
  	geneve->ttl = ttl;
  	geneve->tos = tos;
  	geneve->label = label;
  	geneve->dst_port = dst_port;
  	geneve->collect_md = metadata;
  	geneve->flags = flags;
  
  	t = geneve_find_dev(gn, dst_port, remote, geneve->vni,
  			    &tun_on_same_port, &tun_collect_md);
  	if (t)
  		return -EBUSY;
  
  	/* make enough headroom for basic scenario */
  	encap_len = GENEVE_BASE_HLEN + ETH_HLEN;
  	if (remote->sa.sa_family == AF_INET)
  		encap_len += sizeof(struct iphdr);
  	else
  		encap_len += sizeof(struct ipv6hdr);
  	dev->needed_headroom = encap_len + ETH_HLEN;
  
  	if (metadata) {
  		if (tun_on_same_port)
  			return -EPERM;
  	} else {
  		if (tun_collect_md)
  			return -EPERM;
  	}
  
  	dst_cache_reset(&geneve->dst_cache);
  
  	err = register_netdevice(dev);
  	if (err)
  		return err;
  
  	list_add(&geneve->next, &gn->geneve_list);
  	return 0;
  }
  
  static int geneve_newlink(struct net *net, struct net_device *dev,
  			  struct nlattr *tb[], struct nlattr *data[])
  {
  	__be16 dst_port = htons(GENEVE_UDP_PORT);
  	__u8 ttl = 0, tos = 0;
  	bool metadata = false;
  	union geneve_addr remote = geneve_remote_unspec;
  	__be32 label = 0;
  	__u32 vni = 0;
  	u32 flags = 0;
  
  	if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6])
  		return -EINVAL;
  
  	if (data[IFLA_GENEVE_REMOTE]) {
  		remote.sa.sa_family = AF_INET;
  		remote.sin.sin_addr.s_addr =
  			nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);
  	}
  
  	if (data[IFLA_GENEVE_REMOTE6]) {
  		if (!IS_ENABLED(CONFIG_IPV6))
  			return -EPFNOSUPPORT;
  
  		remote.sa.sa_family = AF_INET6;
  		remote.sin6.sin6_addr =
  			nla_get_in6_addr(data[IFLA_GENEVE_REMOTE6]);
  
  		if (ipv6_addr_type(&remote.sin6.sin6_addr) &
  		    IPV6_ADDR_LINKLOCAL) {
  			netdev_dbg(dev, "link-local remote is unsupported\n");
  			return -EINVAL;
  		}
  	}
  
  	if (data[IFLA_GENEVE_ID])
  		vni = nla_get_u32(data[IFLA_GENEVE_ID]);
  
  	if (data[IFLA_GENEVE_TTL])
  		ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);
  
  	if (data[IFLA_GENEVE_TOS])
  		tos = nla_get_u8(data[IFLA_GENEVE_TOS]);
  
  	if (data[IFLA_GENEVE_LABEL])
  		label = nla_get_be32(data[IFLA_GENEVE_LABEL]) &
  			IPV6_FLOWLABEL_MASK;
  
  	if (data[IFLA_GENEVE_PORT])
  		dst_port = nla_get_be16(data[IFLA_GENEVE_PORT]);
  
  	if (data[IFLA_GENEVE_COLLECT_METADATA])
  		metadata = true;
  
  	if (data[IFLA_GENEVE_UDP_CSUM] &&
  	    !nla_get_u8(data[IFLA_GENEVE_UDP_CSUM]))
  		flags |= GENEVE_F_UDP_ZERO_CSUM_TX;
  
  	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX] &&
  	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]))
  		flags |= GENEVE_F_UDP_ZERO_CSUM6_TX;
  
  	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX] &&
  	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))
  		flags |= GENEVE_F_UDP_ZERO_CSUM6_RX;
  
  	return geneve_configure(net, dev, &remote, vni, ttl, tos, label,
  				dst_port, metadata, flags);
  }
  
  static void geneve_dellink(struct net_device *dev, struct list_head *head)
  {
  	struct geneve_dev *geneve = netdev_priv(dev);
  
  	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 in6_addr)) + /* IFLA_GENEVE_REMOTE{6} */
  		nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TTL */
  		nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TOS */
  		nla_total_size(sizeof(__be32)) +  /* IFLA_GENEVE_LABEL */
  		nla_total_size(sizeof(__be16)) +  /* IFLA_GENEVE_PORT */
  		nla_total_size(0) +	 /* IFLA_GENEVE_COLLECT_METADATA */
  		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_CSUM */
  		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_TX */
  		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_RX */
  		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 (geneve->remote.sa.sa_family == AF_INET) {
  		if (nla_put_in_addr(skb, IFLA_GENEVE_REMOTE,
  				    geneve->remote.sin.sin_addr.s_addr))
  			goto nla_put_failure;
  #if IS_ENABLED(CONFIG_IPV6)
  	} else {
  		if (nla_put_in6_addr(skb, IFLA_GENEVE_REMOTE6,
  				     &geneve->remote.sin6.sin6_addr))
  			goto nla_put_failure;
  #endif
  	}
  
  	if (nla_put_u8(skb, IFLA_GENEVE_TTL, geneve->ttl) ||
  	    nla_put_u8(skb, IFLA_GENEVE_TOS, geneve->tos) ||
  	    nla_put_be32(skb, IFLA_GENEVE_LABEL, geneve->label))
  		goto nla_put_failure;
  
  	if (nla_put_be16(skb, IFLA_GENEVE_PORT, geneve->dst_port))
  		goto nla_put_failure;
  
  	if (geneve->collect_md) {
  		if (nla_put_flag(skb, IFLA_GENEVE_COLLECT_METADATA))
  			goto nla_put_failure;
  	}
  
  	if (nla_put_u8(skb, IFLA_GENEVE_UDP_CSUM,
  		       !(geneve->flags & GENEVE_F_UDP_ZERO_CSUM_TX)) ||
  	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
  		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_TX)) ||
  	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
  		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_RX)))
  		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,
  };
  
  struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
  					u8 name_assign_type, u16 dst_port)
  {
  	struct nlattr *tb[IFLA_MAX + 1];
  	struct net_device *dev;
  	LIST_HEAD(list_kill);
  	int err;
  
  	memset(tb, 0, sizeof(tb));
  	dev = rtnl_create_link(net, name, name_assign_type,
  			       &geneve_link_ops, tb);
  	if (IS_ERR(dev))
  		return dev;
  
  	err = geneve_configure(net, dev, &geneve_remote_unspec,
  			       0, 0, 0, 0, htons(dst_port), true,
  			       GENEVE_F_UDP_ZERO_CSUM6_RX);
  	if (err) {
  		free_netdev(dev);
  		return ERR_PTR(err);
  	}
  
  	/* openvswitch users expect packet sizes to be unrestricted,
  	 * so set the largest MTU we can.
  	 */
  	err = __geneve_change_mtu(dev, IP_MAX_MTU, false);
  	if (err)
  		goto err;
  
  	err = rtnl_configure_link(dev, NULL);
  	if (err < 0)
  		goto err;
  
  	return dev;
  
   err:
  	geneve_dellink(dev, &list_kill);
  	unregister_netdevice_many(&list_kill);
  	return ERR_PTR(err);
  }
  EXPORT_SYMBOL_GPL(geneve_dev_create_fb);
  
  static int geneve_netdevice_event(struct notifier_block *unused,
  				  unsigned long event, void *ptr)
  {
  	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  
  	if (event == NETDEV_UDP_TUNNEL_PUSH_INFO)
  		geneve_push_rx_ports(dev);
  
  	return NOTIFY_DONE;
  }
  
  static struct notifier_block geneve_notifier_block __read_mostly = {
  	.notifier_call = geneve_netdevice_event,
  };
  
  static __net_init int geneve_init_net(struct net *net)
  {
  	struct geneve_net *gn = net_generic(net, geneve_net_id);
  
  	INIT_LIST_HEAD(&gn->geneve_list);
  	INIT_LIST_HEAD(&gn->sock_list);
  	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 = register_netdevice_notifier(&geneve_notifier_block);
  	if (rc)
  		goto out2;
  
  	rc = rtnl_link_register(&geneve_link_ops);
  	if (rc)
  		goto out3;
  
  	return 0;
  
  out3:
  	unregister_netdevice_notifier(&geneve_notifier_block);
  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_netdevice_notifier(&geneve_notifier_block);
  	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");
  