Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2436 insertions, 0 deletions

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
new file mode 100644
index 000000000..d3fba7d8d
--- /dev/null
+++ b/net/ipv6/ip6_gre.c
@@ -0,0 +1,2436 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	GRE over IPv6 protocol decoder.
+ *
+ *	Authors: Dmitry Kozlov (xeb@mail.ru)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <linux/in6.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/hash.h>
+#include <linux/if_tunnel.h>
+#include <linux/ip6_tunnel.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/ip_tunnels.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/addrconf.h>
+#include <net/arp.h>
+#include <net/checksum.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#include <net/ip6_tunnel.h>
+#include <net/gre.h>
+#include <net/erspan.h>
+#include <net/dst_metadata.h>
+
+
+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 IP6_GRE_HASH_SIZE_SHIFT  5
+#define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
+
+static unsigned int ip6gre_net_id __read_mostly;
+struct ip6gre_net {
+	struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
+
+	struct ip6_tnl __rcu *collect_md_tun;
+	struct ip6_tnl __rcu *collect_md_tun_erspan;
+	struct net_device *fb_tunnel_dev;
+};
+
+static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
+static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
+static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly;
+static int ip6gre_tunnel_init(struct net_device *dev);
+static void ip6gre_tunnel_setup(struct net_device *dev);
+static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
+static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
+static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu);
+
+/* Tunnel hash table */
+
+/*
+   4 hash tables:
+
+   3: (remote,local)
+   2: (remote,*)
+   1: (*,local)
+   0: (*,*)
+
+   We require exact key match i.e. if a key is present in packet
+   it will match only tunnel with the same key; if it is not present,
+   it will match only keyless tunnel.
+
+   All keysless packets, if not matched configured keyless tunnels
+   will match fallback tunnel.
+ */
+
+#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
+static u32 HASH_ADDR(const struct in6_addr *addr)
+{
+	u32 hash = ipv6_addr_hash(addr);
+
+	return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
+}
+
+#define tunnels_r_l	tunnels[3]
+#define tunnels_r	tunnels[2]
+#define tunnels_l	tunnels[1]
+#define tunnels_wc	tunnels[0]
+
+/* Given src, dst and key, find appropriate for input tunnel. */
+
+static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
+		const struct in6_addr *remote, const struct in6_addr *local,
+		__be32 key, __be16 gre_proto)
+{
+	struct net *net = dev_net(dev);
+	int link = dev->ifindex;
+	unsigned int h0 = HASH_ADDR(remote);
+	unsigned int h1 = HASH_KEY(key);
+	struct ip6_tnl *t, *cand = NULL;
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+	int dev_type = (gre_proto == htons(ETH_P_TEB) ||
+			gre_proto == htons(ETH_P_ERSPAN) ||
+			gre_proto == htons(ETH_P_ERSPAN2)) ?
+		       ARPHRD_ETHER : ARPHRD_IP6GRE;
+	int score, cand_score = 4;
+	struct net_device *ndev;
+
+	for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
+		if (!ipv6_addr_equal(local, &t->parms.laddr) ||
+		    !ipv6_addr_equal(remote, &t->parms.raddr) ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (t->dev->type != ARPHRD_IP6GRE &&
+		    t->dev->type != dev_type)
+			continue;
+
+		score = 0;
+		if (t->parms.link != link)
+			score |= 1;
+		if (t->dev->type != dev_type)
+			score |= 2;
+		if (score == 0)
+			return t;
+
+		if (score < cand_score) {
+			cand = t;
+			cand_score = score;
+		}
+	}
+
+	for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
+		if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (t->dev->type != ARPHRD_IP6GRE &&
+		    t->dev->type != dev_type)
+			continue;
+
+		score = 0;
+		if (t->parms.link != link)
+			score |= 1;
+		if (t->dev->type != dev_type)
+			score |= 2;
+		if (score == 0)
+			return t;
+
+		if (score < cand_score) {
+			cand = t;
+			cand_score = score;
+		}
+	}
+
+	for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
+		if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
+			  (!ipv6_addr_equal(local, &t->parms.raddr) ||
+				 !ipv6_addr_is_multicast(local))) ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (t->dev->type != ARPHRD_IP6GRE &&
+		    t->dev->type != dev_type)
+			continue;
+
+		score = 0;
+		if (t->parms.link != link)
+			score |= 1;
+		if (t->dev->type != dev_type)
+			score |= 2;
+		if (score == 0)
+			return t;
+
+		if (score < cand_score) {
+			cand = t;
+			cand_score = score;
+		}
+	}
+
+	for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
+		if (t->parms.i_key != key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (t->dev->type != ARPHRD_IP6GRE &&
+		    t->dev->type != dev_type)
+			continue;
+
+		score = 0;
+		if (t->parms.link != link)
+			score |= 1;
+		if (t->dev->type != dev_type)
+			score |= 2;
+		if (score == 0)
+			return t;
+
+		if (score < cand_score) {
+			cand = t;
+			cand_score = score;
+		}
+	}
+
+	if (cand)
+		return cand;
+
+	if (gre_proto == htons(ETH_P_ERSPAN) ||
+	    gre_proto == htons(ETH_P_ERSPAN2))
+		t = rcu_dereference(ign->collect_md_tun_erspan);
+	else
+		t = rcu_dereference(ign->collect_md_tun);
+
+	if (t && t->dev->flags & IFF_UP)
+		return t;
+
+	ndev = READ_ONCE(ign->fb_tunnel_dev);
+	if (ndev && ndev->flags & IFF_UP)
+		return netdev_priv(ndev);
+
+	return NULL;
+}
+
+static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
+		const struct __ip6_tnl_parm *p)
+{
+	const struct in6_addr *remote = &p->raddr;
+	const struct in6_addr *local = &p->laddr;
+	unsigned int h = HASH_KEY(p->i_key);
+	int prio = 0;
+
+	if (!ipv6_addr_any(local))
+		prio |= 1;
+	if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
+		prio |= 2;
+		h ^= HASH_ADDR(remote);
+	}
+
+	return &ign->tunnels[prio][h];
+}
+
+static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+	if (t->parms.collect_md)
+		rcu_assign_pointer(ign->collect_md_tun, t);
+}
+
+static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+	if (t->parms.collect_md)
+		rcu_assign_pointer(ign->collect_md_tun_erspan, t);
+}
+
+static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+	if (t->parms.collect_md)
+		rcu_assign_pointer(ign->collect_md_tun, NULL);
+}
+
+static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
+				       struct ip6_tnl *t)
+{
+	if (t->parms.collect_md)
+		rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
+}
+
+static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
+		const struct ip6_tnl *t)
+{
+	return __ip6gre_bucket(ign, &t->parms);
+}
+
+static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+	struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
+
+	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
+	rcu_assign_pointer(*tp, t);
+}
+
+static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+	struct ip6_tnl __rcu **tp;
+	struct ip6_tnl *iter;
+
+	for (tp = ip6gre_bucket(ign, t);
+	     (iter = rtnl_dereference(*tp)) != NULL;
+	     tp = &iter->next) {
+		if (t == iter) {
+			rcu_assign_pointer(*tp, t->next);
+			break;
+		}
+	}
+}
+
+static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
+					   const struct __ip6_tnl_parm *parms,
+					   int type)
+{
+	const struct in6_addr *remote = &parms->raddr;
+	const struct in6_addr *local = &parms->laddr;
+	__be32 key = parms->i_key;
+	int link = parms->link;
+	struct ip6_tnl *t;
+	struct ip6_tnl __rcu **tp;
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+
+	for (tp = __ip6gre_bucket(ign, parms);
+	     (t = rtnl_dereference(*tp)) != NULL;
+	     tp = &t->next)
+		if (ipv6_addr_equal(local, &t->parms.laddr) &&
+		    ipv6_addr_equal(remote, &t->parms.raddr) &&
+		    key == t->parms.i_key &&
+		    link == t->parms.link &&
+		    type == t->dev->type)
+			break;
+
+	return t;
+}
+
+static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
+		const struct __ip6_tnl_parm *parms, int create)
+{
+	struct ip6_tnl *t, *nt;
+	struct net_device *dev;
+	char name[IFNAMSIZ];
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+
+	t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
+	if (t && create)
+		return NULL;
+	if (t || !create)
+		return t;
+
+	if (parms->name[0]) {
+		if (!dev_valid_name(parms->name))
+			return NULL;
+		strscpy(name, parms->name, IFNAMSIZ);
+	} else {
+		strcpy(name, "ip6gre%d");
+	}
+	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
+			   ip6gre_tunnel_setup);
+	if (!dev)
+		return NULL;
+
+	dev_net_set(dev, net);
+
+	nt = netdev_priv(dev);
+	nt->parms = *parms;
+	dev->rtnl_link_ops = &ip6gre_link_ops;
+
+	nt->dev = dev;
+	nt->net = dev_net(dev);
+
+	if (register_netdevice(dev) < 0)
+		goto failed_free;
+
+	ip6gre_tnl_link_config(nt, 1);
+	ip6gre_tunnel_link(ign, nt);
+	return nt;
+
+failed_free:
+	free_netdev(dev);
+	return NULL;
+}
+
+static void ip6erspan_tunnel_uninit(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
+
+	ip6erspan_tunnel_unlink_md(ign, t);
+	ip6gre_tunnel_unlink(ign, t);
+	dst_cache_reset(&t->dst_cache);
+	netdev_put(dev, &t->dev_tracker);
+}
+
+static void ip6gre_tunnel_uninit(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
+
+	ip6gre_tunnel_unlink_md(ign, t);
+	ip6gre_tunnel_unlink(ign, t);
+	if (ign->fb_tunnel_dev == dev)
+		WRITE_ONCE(ign->fb_tunnel_dev, NULL);
+	dst_cache_reset(&t->dst_cache);
+	netdev_put(dev, &t->dev_tracker);
+}
+
+
+static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+		       u8 type, u8 code, int offset, __be32 info)
+{
+	struct net *net = dev_net(skb->dev);
+	const struct ipv6hdr *ipv6h;
+	struct tnl_ptk_info tpi;
+	struct ip6_tnl *t;
+
+	if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
+			     offset) < 0)
+		return -EINVAL;
+
+	ipv6h = (const struct ipv6hdr *)skb->data;
+	t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
+				 tpi.key, tpi.proto);
+	if (!t)
+		return -ENOENT;
+
+	switch (type) {
+	case ICMPV6_DEST_UNREACH:
+		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
+				    t->parms.name);
+		if (code != ICMPV6_PORT_UNREACH)
+			break;
+		return 0;
+	case ICMPV6_TIME_EXCEED:
+		if (code == ICMPV6_EXC_HOPLIMIT) {
+			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
+					    t->parms.name);
+			break;
+		}
+		return 0;
+	case ICMPV6_PARAMPROB: {
+		struct ipv6_tlv_tnl_enc_lim *tel;
+		__u32 teli;
+
+		teli = 0;
+		if (code == ICMPV6_HDR_FIELD)
+			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
+
+		if (teli && teli == be32_to_cpu(info) - 2) {
+			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
+			if (tel->encap_limit == 0) {
+				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
+						    t->parms.name);
+			}
+		} else {
+			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
+					    t->parms.name);
+		}
+		return 0;
+	}
+	case ICMPV6_PKT_TOOBIG:
+		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
+		return 0;
+	case NDISC_REDIRECT:
+		ip6_redirect(skb, net, skb->dev->ifindex, 0,
+			     sock_net_uid(net, NULL));
+		return 0;
+	}
+
+	if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
+		t->err_count++;
+	else
+		t->err_count = 1;
+	t->err_time = jiffies;
+
+	return 0;
+}
+
+static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
+{
+	const struct ipv6hdr *ipv6h;
+	struct ip6_tnl *tunnel;
+
+	ipv6h = ipv6_hdr(skb);
+	tunnel = ip6gre_tunnel_lookup(skb->dev,
+				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
+				      tpi->proto);
+	if (tunnel) {
+		if (tunnel->parms.collect_md) {
+			struct metadata_dst *tun_dst;
+			__be64 tun_id;
+			__be16 flags;
+
+			flags = tpi->flags;
+			tun_id = key32_to_tunnel_id(tpi->key);
+
+			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id, 0);
+			if (!tun_dst)
+				return PACKET_REJECT;
+
+			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
+		} else {
+			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
+		}
+
+		return PACKET_RCVD;
+	}
+
+	return PACKET_REJECT;
+}
+
+static int ip6erspan_rcv(struct sk_buff *skb,
+			 struct tnl_ptk_info *tpi,
+			 int gre_hdr_len)
+{
+	struct erspan_base_hdr *ershdr;
+	const struct ipv6hdr *ipv6h;
+	struct erspan_md2 *md2;
+	struct ip6_tnl *tunnel;
+	u8 ver;
+
+	ipv6h = ipv6_hdr(skb);
+	ershdr = (struct erspan_base_hdr *)skb->data;
+	ver = ershdr->ver;
+
+	tunnel = ip6gre_tunnel_lookup(skb->dev,
+				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
+				      tpi->proto);
+	if (tunnel) {
+		int len = erspan_hdr_len(ver);
+
+		if (unlikely(!pskb_may_pull(skb, len)))
+			return PACKET_REJECT;
+
+		if (__iptunnel_pull_header(skb, len,
+					   htons(ETH_P_TEB),
+					   false, false) < 0)
+			return PACKET_REJECT;
+
+		if (tunnel->parms.collect_md) {
+			struct erspan_metadata *pkt_md, *md;
+			struct metadata_dst *tun_dst;
+			struct ip_tunnel_info *info;
+			unsigned char *gh;
+			__be64 tun_id;
+			__be16 flags;
+
+			tpi->flags |= TUNNEL_KEY;
+			flags = tpi->flags;
+			tun_id = key32_to_tunnel_id(tpi->key);
+
+			tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
+						  sizeof(*md));
+			if (!tun_dst)
+				return PACKET_REJECT;
+
+			/* skb can be uncloned in __iptunnel_pull_header, so
+			 * old pkt_md is no longer valid and we need to reset
+			 * it
+			 */
+			gh = skb_network_header(skb) +
+			     skb_network_header_len(skb);
+			pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
+							    sizeof(*ershdr));
+			info = &tun_dst->u.tun_info;
+			md = ip_tunnel_info_opts(info);
+			md->version = ver;
+			md2 = &md->u.md2;
+			memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
+						       ERSPAN_V2_MDSIZE);
+			info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
+			info->options_len = sizeof(*md);
+
+			ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
+
+		} else {
+			ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
+		}
+
+		return PACKET_RCVD;
+	}
+
+	return PACKET_REJECT;
+}
+
+static int gre_rcv(struct sk_buff *skb)
+{
+	struct tnl_ptk_info tpi;
+	bool csum_err = false;
+	int hdr_len;
+
+	hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
+	if (hdr_len < 0)
+		goto drop;
+
+	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
+		goto drop;
+
+	if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
+		     tpi.proto == htons(ETH_P_ERSPAN2))) {
+		if (ip6erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
+			return 0;
+		goto out;
+	}
+
+	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
+		return 0;
+
+out:
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int gre_handle_offloads(struct sk_buff *skb, bool csum)
+{
+	return iptunnel_handle_offloads(skb,
+					csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
+}
+
+static void prepare_ip6gre_xmit_ipv4(struct sk_buff *skb,
+				     struct net_device *dev,
+				     struct flowi6 *fl6, __u8 *dsfield,
+				     int *encap_limit)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	struct ip6_tnl *t = netdev_priv(dev);
+
+	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+		*encap_limit = t->parms.encap_limit;
+
+	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
+		*dsfield = ipv4_get_dsfield(iph);
+	else
+		*dsfield = ip6_tclass(t->parms.flowinfo);
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
+		fl6->flowi6_mark = skb->mark;
+	else
+		fl6->flowi6_mark = t->parms.fwmark;
+
+	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+}
+
+static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb,
+				    struct net_device *dev,
+				    struct flowi6 *fl6, __u8 *dsfield,
+				    int *encap_limit)
+{
+	struct ipv6hdr *ipv6h;
+	struct ip6_tnl *t = netdev_priv(dev);
+	__u16 offset;
+
+	offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
+	/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
+	ipv6h = ipv6_hdr(skb);
+
+	if (offset > 0) {
+		struct ipv6_tlv_tnl_enc_lim *tel;
+
+		tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
+		if (tel->encap_limit == 0) {
+			icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
+					ICMPV6_HDR_FIELD, offset + 2);
+			return -1;
+		}
+		*encap_limit = tel->encap_limit - 1;
+	} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
+		*encap_limit = t->parms.encap_limit;
+	}
+
+	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
+		*dsfield = ipv6_get_dsfield(ipv6h);
+	else
+		*dsfield = ip6_tclass(t->parms.flowinfo);
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
+		fl6->flowlabel |= ip6_flowlabel(ipv6h);
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
+		fl6->flowi6_mark = skb->mark;
+	else
+		fl6->flowi6_mark = t->parms.fwmark;
+
+	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+
+	return 0;
+}
+
+static int prepare_ip6gre_xmit_other(struct sk_buff *skb,
+				     struct net_device *dev,
+				     struct flowi6 *fl6, __u8 *dsfield,
+				     int *encap_limit)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+
+	if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+		*encap_limit = t->parms.encap_limit;
+
+	memcpy(fl6, &t->fl.u.ip6, sizeof(*fl6));
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
+		*dsfield = 0;
+	else
+		*dsfield = ip6_tclass(t->parms.flowinfo);
+
+	if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
+		fl6->flowi6_mark = skb->mark;
+	else
+		fl6->flowi6_mark = t->parms.fwmark;
+
+	fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+
+	return 0;
+}
+
+static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)
+{
+	struct ip_tunnel_info *tun_info;
+
+	tun_info = skb_tunnel_info(skb);
+	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))
+		return ERR_PTR(-EINVAL);
+
+	return tun_info;
+}
+
+static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
+			       struct net_device *dev, __u8 dsfield,
+			       struct flowi6 *fl6, int encap_limit,
+			       __u32 *pmtu, __be16 proto)
+{
+	struct ip6_tnl *tunnel = netdev_priv(dev);
+	__be16 protocol;
+	__be16 flags;
+
+	if (dev->type == ARPHRD_ETHER)
+		IPCB(skb)->flags = 0;
+
+	if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
+		fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
+	else
+		fl6->daddr = tunnel->parms.raddr;
+
+	/* Push GRE header. */
+	protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
+
+	if (tunnel->parms.collect_md) {
+		struct ip_tunnel_info *tun_info;
+		const struct ip_tunnel_key *key;
+		int tun_hlen;
+
+		tun_info = skb_tunnel_info_txcheck(skb);
+		if (IS_ERR(tun_info) ||
+		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
+			return -EINVAL;
+
+		key = &tun_info->key;
+		memset(fl6, 0, sizeof(*fl6));
+		fl6->flowi6_proto = IPPROTO_GRE;
+		fl6->daddr = key->u.ipv6.dst;
+		fl6->flowlabel = key->label;
+		fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+		fl6->fl6_gre_key = tunnel_id_to_key32(key->tun_id);
+
+		dsfield = key->tos;
+		flags = key->tun_flags &
+			(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
+		tun_hlen = gre_calc_hlen(flags);
+
+		if (skb_cow_head(skb, dev->needed_headroom ?: tun_hlen + tunnel->encap_hlen))
+			return -ENOMEM;
+
+		gre_build_header(skb, tun_hlen,
+				 flags, protocol,
+				 tunnel_id_to_key32(tun_info->key.tun_id),
+				 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno))
+						      : 0);
+
+	} else {
+		if (skb_cow_head(skb, dev->needed_headroom ?: tunnel->hlen))
+			return -ENOMEM;
+
+		flags = tunnel->parms.o_flags;
+
+		gre_build_header(skb, tunnel->tun_hlen, flags,
+				 protocol, tunnel->parms.o_key,
+				 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno))
+						      : 0);
+	}
+
+	return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
+			    NEXTHDR_GRE);
+}
+
+static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	int encap_limit = -1;
+	struct flowi6 fl6;
+	__u8 dsfield = 0;
+	__u32 mtu;
+	int err;
+
+	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+
+	if (!t->parms.collect_md)
+		prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
+					 &dsfield, &encap_limit);
+
+	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
+	if (err)
+		return -1;
+
+	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
+			  skb->protocol);
+	if (err != 0) {
+		/* XXX: send ICMP error even if DF is not set. */
+		if (err == -EMSGSIZE)
+			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+				      htonl(mtu));
+		return -1;
+	}
+
+	return 0;
+}
+
+static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+	int encap_limit = -1;
+	struct flowi6 fl6;
+	__u8 dsfield = 0;
+	__u32 mtu;
+	int err;
+
+	if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
+		return -1;
+
+	if (!t->parms.collect_md &&
+	    prepare_ip6gre_xmit_ipv6(skb, dev, &fl6, &dsfield, &encap_limit))
+		return -1;
+
+	if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
+		return -1;
+
+	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
+			  &mtu, skb->protocol);
+	if (err != 0) {
+		if (err == -EMSGSIZE)
+			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ * ip6gre_tnl_addr_conflict - compare packet addresses to tunnel's own
+ *   @t: the outgoing tunnel device
+ *   @hdr: IPv6 header from the incoming packet
+ *
+ * Description:
+ *   Avoid trivial tunneling loop by checking that tunnel exit-point
+ *   doesn't match source of incoming packet.
+ *
+ * Return:
+ *   1 if conflict,
+ *   0 else
+ **/
+
+static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
+	const struct ipv6hdr *hdr)
+{
+	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
+}
+
+static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	int encap_limit = -1;
+	struct flowi6 fl6;
+	__u8 dsfield = 0;
+	__u32 mtu;
+	int err;
+
+	if (!t->parms.collect_md &&
+	    prepare_ip6gre_xmit_other(skb, dev, &fl6, &dsfield, &encap_limit))
+		return -1;
+
+	err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
+	if (err)
+		return err;
+	err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, skb->protocol);
+
+	return err;
+}
+
+static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
+	struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net_device_stats *stats = &t->dev->stats;
+	__be16 payload_protocol;
+	int ret;
+
+	if (!pskb_inet_may_pull(skb))
+		goto tx_err;
+
+	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
+		goto tx_err;
+
+	payload_protocol = skb_protocol(skb, true);
+	switch (payload_protocol) {
+	case htons(ETH_P_IP):
+		ret = ip6gre_xmit_ipv4(skb, dev);
+		break;
+	case htons(ETH_P_IPV6):
+		ret = ip6gre_xmit_ipv6(skb, dev);
+		break;
+	default:
+		ret = ip6gre_xmit_other(skb, dev);
+		break;
+	}
+
+	if (ret < 0)
+		goto tx_err;
+
+	return NETDEV_TX_OK;
+
+tx_err:
+	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))
+		stats->tx_errors++;
+	stats->tx_dropped++;
+	kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
+					 struct net_device *dev)
+{
+	struct ip_tunnel_info *tun_info = NULL;
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct dst_entry *dst = skb_dst(skb);
+	struct net_device_stats *stats;
+	bool truncate = false;
+	int encap_limit = -1;
+	__u8 dsfield = false;
+	struct flowi6 fl6;
+	int err = -EINVAL;
+	__be16 proto;
+	__u32 mtu;
+	int nhoff;
+
+	if (!pskb_inet_may_pull(skb))
+		goto tx_err;
+
+	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
+		goto tx_err;
+
+	if (gre_handle_offloads(skb, false))
+		goto tx_err;
+
+	if (skb->len > dev->mtu + dev->hard_header_len) {
+		if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
+			goto tx_err;
+		truncate = true;
+	}
+
+	nhoff = skb_network_offset(skb);
+	if (skb->protocol == htons(ETH_P_IP) &&
+	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
+		truncate = true;
+
+	if (skb->protocol == htons(ETH_P_IPV6)) {
+		int thoff;
+
+		if (skb_transport_header_was_set(skb))
+			thoff = skb_transport_offset(skb);
+		else
+			thoff = nhoff + sizeof(struct ipv6hdr);
+		if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
+			truncate = true;
+	}
+
+	if (skb_cow_head(skb, dev->needed_headroom ?: t->hlen))
+		goto tx_err;
+
+	t->parms.o_flags &= ~TUNNEL_KEY;
+	IPCB(skb)->flags = 0;
+
+	/* For collect_md mode, derive fl6 from the tunnel key,
+	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
+	 */
+	if (t->parms.collect_md) {
+		const struct ip_tunnel_key *key;
+		struct erspan_metadata *md;
+		__be32 tun_id;
+
+		tun_info = skb_tunnel_info_txcheck(skb);
+		if (IS_ERR(tun_info) ||
+		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))
+			goto tx_err;
+
+		key = &tun_info->key;
+		memset(&fl6, 0, sizeof(fl6));
+		fl6.flowi6_proto = IPPROTO_GRE;
+		fl6.daddr = key->u.ipv6.dst;
+		fl6.flowlabel = key->label;
+		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
+		fl6.fl6_gre_key = tunnel_id_to_key32(key->tun_id);
+
+		dsfield = key->tos;
+		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
+			goto tx_err;
+		if (tun_info->options_len < sizeof(*md))
+			goto tx_err;
+		md = ip_tunnel_info_opts(tun_info);
+
+		tun_id = tunnel_id_to_key32(key->tun_id);
+		if (md->version == 1) {
+			erspan_build_header(skb,
+					    ntohl(tun_id),
+					    ntohl(md->u.index), truncate,
+					    false);
+			proto = htons(ETH_P_ERSPAN);
+		} else if (md->version == 2) {
+			erspan_build_header_v2(skb,
+					       ntohl(tun_id),
+					       md->u.md2.dir,
+					       get_hwid(&md->u.md2),
+					       truncate, false);
+			proto = htons(ETH_P_ERSPAN2);
+		} else {
+			goto tx_err;
+		}
+	} else {
+		switch (skb->protocol) {
+		case htons(ETH_P_IP):
+			memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+			prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
+						 &dsfield, &encap_limit);
+			break;
+		case htons(ETH_P_IPV6):
+			if (ipv6_addr_equal(&t->parms.raddr, &ipv6_hdr(skb)->saddr))
+				goto tx_err;
+			if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
+						     &dsfield, &encap_limit))
+				goto tx_err;
+			break;
+		default:
+			memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
+			break;
+		}
+
+		if (t->parms.erspan_ver == 1) {
+			erspan_build_header(skb, ntohl(t->parms.o_key),
+					    t->parms.index,
+					    truncate, false);
+			proto = htons(ETH_P_ERSPAN);
+		} else if (t->parms.erspan_ver == 2) {
+			erspan_build_header_v2(skb, ntohl(t->parms.o_key),
+					       t->parms.dir,
+					       t->parms.hwid,
+					       truncate, false);
+			proto = htons(ETH_P_ERSPAN2);
+		} else {
+			goto tx_err;
+		}
+
+		fl6.daddr = t->parms.raddr;
+	}
+
+	/* Push GRE header. */
+	gre_build_header(skb, 8, TUNNEL_SEQ, proto, 0, htonl(atomic_fetch_inc(&t->o_seqno)));
+
+	/* TooBig packet may have updated dst->dev's mtu */
+	if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
+		dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
+
+	err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
+			   NEXTHDR_GRE);
+	if (err != 0) {
+		/* XXX: send ICMP error even if DF is not set. */
+		if (err == -EMSGSIZE) {
+			if (skb->protocol == htons(ETH_P_IP))
+				icmp_ndo_send(skb, ICMP_DEST_UNREACH,
+					      ICMP_FRAG_NEEDED, htonl(mtu));
+			else
+				icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+		}
+
+		goto tx_err;
+	}
+	return NETDEV_TX_OK;
+
+tx_err:
+	stats = &t->dev->stats;
+	if (!IS_ERR(tun_info))
+		stats->tx_errors++;
+	stats->tx_dropped++;
+	kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
+{
+	struct net_device *dev = t->dev;
+	struct __ip6_tnl_parm *p = &t->parms;
+	struct flowi6 *fl6 = &t->fl.u.ip6;
+
+	if (dev->type != ARPHRD_ETHER) {
+		__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
+		memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
+	}
+
+	/* Set up flowi template */
+	fl6->saddr = p->laddr;
+	fl6->daddr = p->raddr;
+	fl6->flowi6_oif = p->link;
+	fl6->flowlabel = 0;
+	fl6->flowi6_proto = IPPROTO_GRE;
+	fl6->fl6_gre_key = t->parms.o_key;
+
+	if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
+		fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
+	if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
+		fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
+
+	p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
+	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
+
+	if (p->flags&IP6_TNL_F_CAP_XMIT &&
+			p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
+		dev->flags |= IFF_POINTOPOINT;
+	else
+		dev->flags &= ~IFF_POINTOPOINT;
+}
+
+static void ip6gre_tnl_link_config_route(struct ip6_tnl *t, int set_mtu,
+					 int t_hlen)
+{
+	const struct __ip6_tnl_parm *p = &t->parms;
+	struct net_device *dev = t->dev;
+
+	if (p->flags & IP6_TNL_F_CAP_XMIT) {
+		int strict = (ipv6_addr_type(&p->raddr) &
+			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
+
+		struct rt6_info *rt = rt6_lookup(t->net,
+						 &p->raddr, &p->laddr,
+						 p->link, NULL, strict);
+
+		if (!rt)
+			return;
+
+		if (rt->dst.dev) {
+			unsigned short dst_len = rt->dst.dev->hard_header_len +
+						 t_hlen;
+
+			if (t->dev->header_ops)
+				dev->hard_header_len = dst_len;
+			else
+				dev->needed_headroom = dst_len;
+
+			if (set_mtu) {
+				int mtu = rt->dst.dev->mtu - t_hlen;
+
+				if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+					mtu -= 8;
+				if (dev->type == ARPHRD_ETHER)
+					mtu -= ETH_HLEN;
+
+				if (mtu < IPV6_MIN_MTU)
+					mtu = IPV6_MIN_MTU;
+				WRITE_ONCE(dev->mtu, mtu);
+			}
+		}
+		ip6_rt_put(rt);
+	}
+}
+
+static int ip6gre_calc_hlen(struct ip6_tnl *tunnel)
+{
+	int t_hlen;
+
+	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
+
+	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
+
+	if (tunnel->dev->header_ops)
+		tunnel->dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+	else
+		tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
+
+	return t_hlen;
+}
+
+static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
+{
+	ip6gre_tnl_link_config_common(t);
+	ip6gre_tnl_link_config_route(t, set_mtu, ip6gre_calc_hlen(t));
+}
+
+static void ip6gre_tnl_copy_tnl_parm(struct ip6_tnl *t,
+				     const struct __ip6_tnl_parm *p)
+{
+	t->parms.laddr = p->laddr;
+	t->parms.raddr = p->raddr;
+	t->parms.flags = p->flags;
+	t->parms.hop_limit = p->hop_limit;
+	t->parms.encap_limit = p->encap_limit;
+	t->parms.flowinfo = p->flowinfo;
+	t->parms.link = p->link;
+	t->parms.proto = p->proto;
+	t->parms.i_key = p->i_key;
+	t->parms.o_key = p->o_key;
+	t->parms.i_flags = p->i_flags;
+	t->parms.o_flags = p->o_flags;
+	t->parms.fwmark = p->fwmark;
+	t->parms.erspan_ver = p->erspan_ver;
+	t->parms.index = p->index;
+	t->parms.dir = p->dir;
+	t->parms.hwid = p->hwid;
+	dst_cache_reset(&t->dst_cache);
+}
+
+static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
+			     int set_mtu)
+{
+	ip6gre_tnl_copy_tnl_parm(t, p);
+	ip6gre_tnl_link_config(t, set_mtu);
+	return 0;
+}
+
+static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
+	const struct ip6_tnl_parm2 *u)
+{
+	p->laddr = u->laddr;
+	p->raddr = u->raddr;
+	p->flags = u->flags;
+	p->hop_limit = u->hop_limit;
+	p->encap_limit = u->encap_limit;
+	p->flowinfo = u->flowinfo;
+	p->link = u->link;
+	p->i_key = u->i_key;
+	p->o_key = u->o_key;
+	p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
+	p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
+	memcpy(p->name, u->name, sizeof(u->name));
+}
+
+static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
+	const struct __ip6_tnl_parm *p)
+{
+	u->proto = IPPROTO_GRE;
+	u->laddr = p->laddr;
+	u->raddr = p->raddr;
+	u->flags = p->flags;
+	u->hop_limit = p->hop_limit;
+	u->encap_limit = p->encap_limit;
+	u->flowinfo = p->flowinfo;
+	u->link = p->link;
+	u->i_key = p->i_key;
+	u->o_key = p->o_key;
+	u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
+	u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
+	memcpy(u->name, p->name, sizeof(u->name));
+}
+
+static int ip6gre_tunnel_siocdevprivate(struct net_device *dev,
+					struct ifreq *ifr, void __user *data,
+					int cmd)
+{
+	int err = 0;
+	struct ip6_tnl_parm2 p;
+	struct __ip6_tnl_parm p1;
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net *net = t->net;
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+
+	memset(&p1, 0, sizeof(p1));
+
+	switch (cmd) {
+	case SIOCGETTUNNEL:
+		if (dev == ign->fb_tunnel_dev) {
+			if (copy_from_user(&p, data, sizeof(p))) {
+				err = -EFAULT;
+				break;
+			}
+			ip6gre_tnl_parm_from_user(&p1, &p);
+			t = ip6gre_tunnel_locate(net, &p1, 0);
+			if (!t)
+				t = netdev_priv(dev);
+		}
+		memset(&p, 0, sizeof(p));
+		ip6gre_tnl_parm_to_user(&p, &t->parms);
+		if (copy_to_user(data, &p, sizeof(p)))
+			err = -EFAULT;
+		break;
+
+	case SIOCADDTUNNEL:
+	case SIOCCHGTUNNEL:
+		err = -EPERM;
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+			goto done;
+
+		err = -EFAULT;
+		if (copy_from_user(&p, data, sizeof(p)))
+			goto done;
+
+		err = -EINVAL;
+		if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
+			goto done;
+
+		if (!(p.i_flags&GRE_KEY))
+			p.i_key = 0;
+		if (!(p.o_flags&GRE_KEY))
+			p.o_key = 0;
+
+		ip6gre_tnl_parm_from_user(&p1, &p);
+		t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
+
+		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+			if (t) {
+				if (t->dev != dev) {
+					err = -EEXIST;
+					break;
+				}
+			} else {
+				t = netdev_priv(dev);
+
+				ip6gre_tunnel_unlink(ign, t);
+				synchronize_net();
+				ip6gre_tnl_change(t, &p1, 1);
+				ip6gre_tunnel_link(ign, t);
+				netdev_state_change(dev);
+			}
+		}
+
+		if (t) {
+			err = 0;
+
+			memset(&p, 0, sizeof(p));
+			ip6gre_tnl_parm_to_user(&p, &t->parms);
+			if (copy_to_user(data, &p, sizeof(p)))
+				err = -EFAULT;
+		} else
+			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+		break;
+
+	case SIOCDELTUNNEL:
+		err = -EPERM;
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+			goto done;
+
+		if (dev == ign->fb_tunnel_dev) {
+			err = -EFAULT;
+			if (copy_from_user(&p, data, sizeof(p)))
+				goto done;
+			err = -ENOENT;
+			ip6gre_tnl_parm_from_user(&p1, &p);
+			t = ip6gre_tunnel_locate(net, &p1, 0);
+			if (!t)
+				goto done;
+			err = -EPERM;
+			if (t == netdev_priv(ign->fb_tunnel_dev))
+				goto done;
+			dev = t->dev;
+		}
+		unregister_netdevice(dev);
+		err = 0;
+		break;
+
+	default:
+		err = -EINVAL;
+	}
+
+done:
+	return err;
+}
+
+static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
+			 unsigned short type, const void *daddr,
+			 const void *saddr, unsigned int len)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct ipv6hdr *ipv6h;
+	__be16 *p;
+
+	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
+	ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
+						  t->fl.u.ip6.flowlabel,
+						  true, &t->fl.u.ip6));
+	ipv6h->hop_limit = t->parms.hop_limit;
+	ipv6h->nexthdr = NEXTHDR_GRE;
+	ipv6h->saddr = t->parms.laddr;
+	ipv6h->daddr = t->parms.raddr;
+
+	p = (__be16 *)(ipv6h + 1);
+	p[0] = t->parms.o_flags;
+	p[1] = htons(type);
+
+	/*
+	 *	Set the source hardware address.
+	 */
+
+	if (saddr)
+		memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
+	if (daddr)
+		memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
+	if (!ipv6_addr_any(&ipv6h->daddr))
+		return t->hlen;
+
+	return -t->hlen;
+}
+
+static const struct header_ops ip6gre_header_ops = {
+	.create	= ip6gre_header,
+};
+
+static const struct net_device_ops ip6gre_netdev_ops = {
+	.ndo_init		= ip6gre_tunnel_init,
+	.ndo_uninit		= ip6gre_tunnel_uninit,
+	.ndo_start_xmit		= ip6gre_tunnel_xmit,
+	.ndo_siocdevprivate	= ip6gre_tunnel_siocdevprivate,
+	.ndo_change_mtu		= ip6_tnl_change_mtu,
+	.ndo_get_stats64	= dev_get_tstats64,
+	.ndo_get_iflink		= ip6_tnl_get_iflink,
+};
+
+static void ip6gre_dev_free(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+
+	gro_cells_destroy(&t->gro_cells);
+	dst_cache_destroy(&t->dst_cache);
+	free_percpu(dev->tstats);
+}
+
+static void ip6gre_tunnel_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &ip6gre_netdev_ops;
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = ip6gre_dev_free;
+
+	dev->type = ARPHRD_IP6GRE;
+
+	dev->flags |= IFF_NOARP;
+	dev->addr_len = sizeof(struct in6_addr);
+	netif_keep_dst(dev);
+	/* This perm addr will be used as interface identifier by IPv6 */
+	dev->addr_assign_type = NET_ADDR_RANDOM;
+	eth_random_addr(dev->perm_addr);
+}
+
+#define GRE6_FEATURES (NETIF_F_SG |		\
+		       NETIF_F_FRAGLIST |	\
+		       NETIF_F_HIGHDMA |	\
+		       NETIF_F_HW_CSUM)
+
+static void ip6gre_tnl_init_features(struct net_device *dev)
+{
+	struct ip6_tnl *nt = netdev_priv(dev);
+	__be16 flags;
+
+	dev->features		|= GRE6_FEATURES | NETIF_F_LLTX;
+	dev->hw_features	|= GRE6_FEATURES;
+
+	flags = nt->parms.o_flags;
+
+	/* TCP offload with GRE SEQ is not supported, nor can we support 2
+	 * levels of outer headers requiring an update.
+	 */
+	if (flags & TUNNEL_SEQ)
+		return;
+	if (flags & TUNNEL_CSUM && nt->encap.type != TUNNEL_ENCAP_NONE)
+		return;
+
+	dev->features |= NETIF_F_GSO_SOFTWARE;
+	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+}
+
+static int ip6gre_tunnel_init_common(struct net_device *dev)
+{
+	struct ip6_tnl *tunnel;
+	int ret;
+	int t_hlen;
+
+	tunnel = netdev_priv(dev);
+
+	tunnel->dev = dev;
+	tunnel->net = dev_net(dev);
+	strcpy(tunnel->parms.name, dev->name);
+
+	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+
+	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
+	if (ret)
+		goto cleanup_alloc_pcpu_stats;
+
+	ret = gro_cells_init(&tunnel->gro_cells, dev);
+	if (ret)
+		goto cleanup_dst_cache_init;
+
+	t_hlen = ip6gre_calc_hlen(tunnel);
+	dev->mtu = ETH_DATA_LEN - t_hlen;
+	if (dev->type == ARPHRD_ETHER)
+		dev->mtu -= ETH_HLEN;
+	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+		dev->mtu -= 8;
+
+	if (tunnel->parms.collect_md) {
+		netif_keep_dst(dev);
+	}
+	ip6gre_tnl_init_features(dev);
+
+	netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
+	return 0;
+
+cleanup_dst_cache_init:
+	dst_cache_destroy(&tunnel->dst_cache);
+cleanup_alloc_pcpu_stats:
+	free_percpu(dev->tstats);
+	dev->tstats = NULL;
+	return ret;
+}
+
+static int ip6gre_tunnel_init(struct net_device *dev)
+{
+	struct ip6_tnl *tunnel;
+	int ret;
+
+	ret = ip6gre_tunnel_init_common(dev);
+	if (ret)
+		return ret;
+
+	tunnel = netdev_priv(dev);
+
+	if (tunnel->parms.collect_md)
+		return 0;
+
+	__dev_addr_set(dev, &tunnel->parms.laddr, sizeof(struct in6_addr));
+	memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
+
+	if (ipv6_addr_any(&tunnel->parms.raddr))
+		dev->header_ops = &ip6gre_header_ops;
+
+	return 0;
+}
+
+static void ip6gre_fb_tunnel_init(struct net_device *dev)
+{
+	struct ip6_tnl *tunnel = netdev_priv(dev);
+
+	tunnel->dev = dev;
+	tunnel->net = dev_net(dev);
+	strcpy(tunnel->parms.name, dev->name);
+
+	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;
+}
+
+static struct inet6_protocol ip6gre_protocol __read_mostly = {
+	.handler     = gre_rcv,
+	.err_handler = ip6gre_err,
+	.flags       = INET6_PROTO_FINAL,
+};
+
+static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
+{
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+	struct net_device *dev, *aux;
+	int prio;
+
+	for_each_netdev_safe(net, dev, aux)
+		if (dev->rtnl_link_ops == &ip6gre_link_ops ||
+		    dev->rtnl_link_ops == &ip6gre_tap_ops ||
+		    dev->rtnl_link_ops == &ip6erspan_tap_ops)
+			unregister_netdevice_queue(dev, head);
+
+	for (prio = 0; prio < 4; prio++) {
+		int h;
+		for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
+			struct ip6_tnl *t;
+
+			t = rtnl_dereference(ign->tunnels[prio][h]);
+
+			while (t) {
+				/* If dev is in the same netns, it has already
+				 * been added to the list by the previous loop.
+				 */
+				if (!net_eq(dev_net(t->dev), net))
+					unregister_netdevice_queue(t->dev,
+								   head);
+				t = rtnl_dereference(t->next);
+			}
+		}
+	}
+}
+
+static int __net_init ip6gre_init_net(struct net *net)
+{
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+	struct net_device *ndev;
+	int err;
+
+	if (!net_has_fallback_tunnels(net))
+		return 0;
+	ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
+			    NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
+	if (!ndev) {
+		err = -ENOMEM;
+		goto err_alloc_dev;
+	}
+	ign->fb_tunnel_dev = ndev;
+	dev_net_set(ign->fb_tunnel_dev, net);
+	/* FB netdevice is special: we have one, and only one per netns.
+	 * Allowing to move it to another netns is clearly unsafe.
+	 */
+	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+
+
+	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
+	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
+
+	err = register_netdev(ign->fb_tunnel_dev);
+	if (err)
+		goto err_reg_dev;
+
+	rcu_assign_pointer(ign->tunnels_wc[0],
+			   netdev_priv(ign->fb_tunnel_dev));
+	return 0;
+
+err_reg_dev:
+	free_netdev(ndev);
+err_alloc_dev:
+	return err;
+}
+
+static void __net_exit ip6gre_exit_batch_net(struct list_head *net_list)
+{
+	struct net *net;
+	LIST_HEAD(list);
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list)
+		ip6gre_destroy_tunnels(net, &list);
+	unregister_netdevice_many(&list);
+	rtnl_unlock();
+}
+
+static struct pernet_operations ip6gre_net_ops = {
+	.init = ip6gre_init_net,
+	.exit_batch = ip6gre_exit_batch_net,
+	.id   = &ip6gre_net_id,
+	.size = sizeof(struct ip6gre_net),
+};
+
+static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
+				  struct netlink_ext_ack *extack)
+{
+	__be16 flags;
+
+	if (!data)
+		return 0;
+
+	flags = 0;
+	if (data[IFLA_GRE_IFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+	if (data[IFLA_GRE_OFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+	if (flags & (GRE_VERSION|GRE_ROUTING))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
+			       struct netlink_ext_ack *extack)
+{
+	struct in6_addr daddr;
+
+	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)
+		goto out;
+
+	if (data[IFLA_GRE_REMOTE]) {
+		daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
+		if (ipv6_addr_any(&daddr))
+			return -EINVAL;
+	}
+
+out:
+	return ip6gre_tunnel_validate(tb, data, extack);
+}
+
+static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
+				  struct netlink_ext_ack *extack)
+{
+	__be16 flags = 0;
+	int ret, ver = 0;
+
+	if (!data)
+		return 0;
+
+	ret = ip6gre_tap_validate(tb, data, extack);
+	if (ret)
+		return ret;
+
+	/* ERSPAN should only have GRE sequence and key flag */
+	if (data[IFLA_GRE_OFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+	if (data[IFLA_GRE_IFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+	if (!data[IFLA_GRE_COLLECT_METADATA] &&
+	    flags != (GRE_SEQ | GRE_KEY))
+		return -EINVAL;
+
+	/* ERSPAN Session ID only has 10-bit. Since we reuse
+	 * 32-bit key field as ID, check it's range.
+	 */
+	if (data[IFLA_GRE_IKEY] &&
+	    (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
+		return -EINVAL;
+
+	if (data[IFLA_GRE_OKEY] &&
+	    (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
+		return -EINVAL;
+
+	if (data[IFLA_GRE_ERSPAN_VER]) {
+		ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
+		if (ver != 1 && ver != 2)
+			return -EINVAL;
+	}
+
+	if (ver == 1) {
+		if (data[IFLA_GRE_ERSPAN_INDEX]) {
+			u32 index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
+
+			if (index & ~INDEX_MASK)
+				return -EINVAL;
+		}
+	} else if (ver == 2) {
+		if (data[IFLA_GRE_ERSPAN_DIR]) {
+			u16 dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
+
+			if (dir & ~(DIR_MASK >> DIR_OFFSET))
+				return -EINVAL;
+		}
+
+		if (data[IFLA_GRE_ERSPAN_HWID]) {
+			u16 hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
+
+			if (hwid & ~(HWID_MASK >> HWID_OFFSET))
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static void ip6erspan_set_version(struct nlattr *data[],
+				  struct __ip6_tnl_parm *parms)
+{
+	if (!data)
+		return;
+
+	parms->erspan_ver = 1;
+	if (data[IFLA_GRE_ERSPAN_VER])
+		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
+
+	if (parms->erspan_ver == 1) {
+		if (data[IFLA_GRE_ERSPAN_INDEX])
+			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
+	} else if (parms->erspan_ver == 2) {
+		if (data[IFLA_GRE_ERSPAN_DIR])
+			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
+		if (data[IFLA_GRE_ERSPAN_HWID])
+			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
+	}
+}
+
+static void ip6gre_netlink_parms(struct nlattr *data[],
+				struct __ip6_tnl_parm *parms)
+{
+	memset(parms, 0, sizeof(*parms));
+
+	if (!data)
+		return;
+
+	if (data[IFLA_GRE_LINK])
+		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
+
+	if (data[IFLA_GRE_IFLAGS])
+		parms->i_flags = gre_flags_to_tnl_flags(
+				nla_get_be16(data[IFLA_GRE_IFLAGS]));
+
+	if (data[IFLA_GRE_OFLAGS])
+		parms->o_flags = gre_flags_to_tnl_flags(
+				nla_get_be16(data[IFLA_GRE_OFLAGS]));
+
+	if (data[IFLA_GRE_IKEY])
+		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
+
+	if (data[IFLA_GRE_OKEY])
+		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
+
+	if (data[IFLA_GRE_LOCAL])
+		parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
+
+	if (data[IFLA_GRE_REMOTE])
+		parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
+
+	if (data[IFLA_GRE_TTL])
+		parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
+
+	if (data[IFLA_GRE_ENCAP_LIMIT])
+		parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
+
+	if (data[IFLA_GRE_FLOWINFO])
+		parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
+
+	if (data[IFLA_GRE_FLAGS])
+		parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
+
+	if (data[IFLA_GRE_FWMARK])
+		parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
+
+	if (data[IFLA_GRE_COLLECT_METADATA])
+		parms->collect_md = true;
+}
+
+static int ip6gre_tap_init(struct net_device *dev)
+{
+	int ret;
+
+	ret = ip6gre_tunnel_init_common(dev);
+	if (ret)
+		return ret;
+
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+
+	return 0;
+}
+
+static const struct net_device_ops ip6gre_tap_netdev_ops = {
+	.ndo_init = ip6gre_tap_init,
+	.ndo_uninit = ip6gre_tunnel_uninit,
+	.ndo_start_xmit = ip6gre_tunnel_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_validate_addr = eth_validate_addr,
+	.ndo_change_mtu = ip6_tnl_change_mtu,
+	.ndo_get_stats64 = dev_get_tstats64,
+	.ndo_get_iflink = ip6_tnl_get_iflink,
+};
+
+static int ip6erspan_calc_hlen(struct ip6_tnl *tunnel)
+{
+	int t_hlen;
+
+	tunnel->tun_hlen = 8;
+	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
+		       erspan_hdr_len(tunnel->parms.erspan_ver);
+
+	t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
+	tunnel->dev->needed_headroom = LL_MAX_HEADER + t_hlen;
+	return t_hlen;
+}
+
+static int ip6erspan_tap_init(struct net_device *dev)
+{
+	struct ip6_tnl *tunnel;
+	int t_hlen;
+	int ret;
+
+	tunnel = netdev_priv(dev);
+
+	tunnel->dev = dev;
+	tunnel->net = dev_net(dev);
+	strcpy(tunnel->parms.name, dev->name);
+
+	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+
+	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
+	if (ret)
+		goto cleanup_alloc_pcpu_stats;
+
+	ret = gro_cells_init(&tunnel->gro_cells, dev);
+	if (ret)
+		goto cleanup_dst_cache_init;
+
+	t_hlen = ip6erspan_calc_hlen(tunnel);
+	dev->mtu = ETH_DATA_LEN - t_hlen;
+	if (dev->type == ARPHRD_ETHER)
+		dev->mtu -= ETH_HLEN;
+	if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+		dev->mtu -= 8;
+
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	ip6erspan_tnl_link_config(tunnel, 1);
+
+	netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
+	return 0;
+
+cleanup_dst_cache_init:
+	dst_cache_destroy(&tunnel->dst_cache);
+cleanup_alloc_pcpu_stats:
+	free_percpu(dev->tstats);
+	dev->tstats = NULL;
+	return ret;
+}
+
+static const struct net_device_ops ip6erspan_netdev_ops = {
+	.ndo_init =		ip6erspan_tap_init,
+	.ndo_uninit =		ip6erspan_tunnel_uninit,
+	.ndo_start_xmit =	ip6erspan_tunnel_xmit,
+	.ndo_set_mac_address =	eth_mac_addr,
+	.ndo_validate_addr =	eth_validate_addr,
+	.ndo_change_mtu =	ip6_tnl_change_mtu,
+	.ndo_get_stats64 =	dev_get_tstats64,
+	.ndo_get_iflink =	ip6_tnl_get_iflink,
+};
+
+static void ip6gre_tap_setup(struct net_device *dev)
+{
+
+	ether_setup(dev);
+
+	dev->max_mtu = 0;
+	dev->netdev_ops = &ip6gre_tap_netdev_ops;
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = ip6gre_dev_free;
+
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	netif_keep_dst(dev);
+}
+
+static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
+				       struct ip_tunnel_encap *ipencap)
+{
+	bool ret = false;
+
+	memset(ipencap, 0, sizeof(*ipencap));
+
+	if (!data)
+		return ret;
+
+	if (data[IFLA_GRE_ENCAP_TYPE]) {
+		ret = true;
+		ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
+	}
+
+	if (data[IFLA_GRE_ENCAP_FLAGS]) {
+		ret = true;
+		ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
+	}
+
+	if (data[IFLA_GRE_ENCAP_SPORT]) {
+		ret = true;
+		ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
+	}
+
+	if (data[IFLA_GRE_ENCAP_DPORT]) {
+		ret = true;
+		ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
+	}
+
+	return ret;
+}
+
+static int ip6gre_newlink_common(struct net *src_net, struct net_device *dev,
+				 struct nlattr *tb[], struct nlattr *data[],
+				 struct netlink_ext_ack *extack)
+{
+	struct ip6_tnl *nt;
+	struct ip_tunnel_encap ipencap;
+	int err;
+
+	nt = netdev_priv(dev);
+
+	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
+		int err = ip6_tnl_encap_setup(nt, &ipencap);
+
+		if (err < 0)
+			return err;
+	}
+
+	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+		eth_hw_addr_random(dev);
+
+	nt->dev = dev;
+	nt->net = dev_net(dev);
+
+	err = register_netdevice(dev);
+	if (err)
+		goto out;
+
+	if (tb[IFLA_MTU])
+		ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
+
+out:
+	return err;
+}
+
+static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
+			  struct nlattr *tb[], struct nlattr *data[],
+			  struct netlink_ext_ack *extack)
+{
+	struct ip6_tnl *nt = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct ip6gre_net *ign;
+	int err;
+
+	ip6gre_netlink_parms(data, &nt->parms);
+	ign = net_generic(net, ip6gre_net_id);
+
+	if (nt->parms.collect_md) {
+		if (rtnl_dereference(ign->collect_md_tun))
+			return -EEXIST;
+	} else {
+		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
+			return -EEXIST;
+	}
+
+	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	if (!err) {
+		ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
+		ip6gre_tunnel_link_md(ign, nt);
+		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
+	}
+	return err;
+}
+
+static struct ip6_tnl *
+ip6gre_changelink_common(struct net_device *dev, struct nlattr *tb[],
+			 struct nlattr *data[], struct __ip6_tnl_parm *p_p,
+			 struct netlink_ext_ack *extack)
+{
+	struct ip6_tnl *t, *nt = netdev_priv(dev);
+	struct net *net = nt->net;
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+	struct ip_tunnel_encap ipencap;
+
+	if (dev == ign->fb_tunnel_dev)
+		return ERR_PTR(-EINVAL);
+
+	if (ip6gre_netlink_encap_parms(data, &ipencap)) {
+		int err = ip6_tnl_encap_setup(nt, &ipencap);
+
+		if (err < 0)
+			return ERR_PTR(err);
+	}
+
+	ip6gre_netlink_parms(data, p_p);
+
+	t = ip6gre_tunnel_locate(net, p_p, 0);
+
+	if (t) {
+		if (t->dev != dev)
+			return ERR_PTR(-EEXIST);
+	} else {
+		t = nt;
+	}
+
+	return t;
+}
+
+static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
+			     struct nlattr *data[],
+			     struct netlink_ext_ack *extack)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
+	struct __ip6_tnl_parm p;
+
+	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
+	if (IS_ERR(t))
+		return PTR_ERR(t);
+
+	ip6gre_tunnel_unlink_md(ign, t);
+	ip6gre_tunnel_unlink(ign, t);
+	ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
+	ip6gre_tunnel_link_md(ign, t);
+	ip6gre_tunnel_link(ign, t);
+	return 0;
+}
+
+static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct net *net = dev_net(dev);
+	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+
+	if (dev != ign->fb_tunnel_dev)
+		unregister_netdevice_queue(dev, head);
+}
+
+static size_t ip6gre_get_size(const struct net_device *dev)
+{
+	return
+		/* IFLA_GRE_LINK */
+		nla_total_size(4) +
+		/* IFLA_GRE_IFLAGS */
+		nla_total_size(2) +
+		/* IFLA_GRE_OFLAGS */
+		nla_total_size(2) +
+		/* IFLA_GRE_IKEY */
+		nla_total_size(4) +
+		/* IFLA_GRE_OKEY */
+		nla_total_size(4) +
+		/* IFLA_GRE_LOCAL */
+		nla_total_size(sizeof(struct in6_addr)) +
+		/* IFLA_GRE_REMOTE */
+		nla_total_size(sizeof(struct in6_addr)) +
+		/* IFLA_GRE_TTL */
+		nla_total_size(1) +
+		/* IFLA_GRE_ENCAP_LIMIT */
+		nla_total_size(1) +
+		/* IFLA_GRE_FLOWINFO */
+		nla_total_size(4) +
+		/* IFLA_GRE_FLAGS */
+		nla_total_size(4) +
+		/* IFLA_GRE_ENCAP_TYPE */
+		nla_total_size(2) +
+		/* IFLA_GRE_ENCAP_FLAGS */
+		nla_total_size(2) +
+		/* IFLA_GRE_ENCAP_SPORT */
+		nla_total_size(2) +
+		/* IFLA_GRE_ENCAP_DPORT */
+		nla_total_size(2) +
+		/* IFLA_GRE_COLLECT_METADATA */
+		nla_total_size(0) +
+		/* IFLA_GRE_FWMARK */
+		nla_total_size(4) +
+		/* IFLA_GRE_ERSPAN_INDEX */
+		nla_total_size(4) +
+		0;
+}
+
+static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct __ip6_tnl_parm *p = &t->parms;
+	__be16 o_flags = p->o_flags;
+
+	if (p->erspan_ver == 1 || p->erspan_ver == 2) {
+		if (!p->collect_md)
+			o_flags |= TUNNEL_KEY;
+
+		if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, p->erspan_ver))
+			goto nla_put_failure;
+
+		if (p->erspan_ver == 1) {
+			if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
+				goto nla_put_failure;
+		} else {
+			if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, p->dir))
+				goto nla_put_failure;
+			if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, p->hwid))
+				goto nla_put_failure;
+		}
+	}
+
+	if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
+	    nla_put_be16(skb, IFLA_GRE_IFLAGS,
+			 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
+	    nla_put_be16(skb, IFLA_GRE_OFLAGS,
+			 gre_tnl_flags_to_gre_flags(o_flags)) ||
+	    nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
+	    nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
+	    nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
+	    nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
+	    nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
+	    nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
+	    nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
+	    nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
+	    nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
+		goto nla_put_failure;
+
+	if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
+			t->encap.type) ||
+	    nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
+			 t->encap.sport) ||
+	    nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
+			 t->encap.dport) ||
+	    nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
+			t->encap.flags))
+		goto nla_put_failure;
+
+	if (p->collect_md) {
+		if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
+			goto nla_put_failure;
+	}
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
+	[IFLA_GRE_LINK]        = { .type = NLA_U32 },
+	[IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
+	[IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
+	[IFLA_GRE_IKEY]        = { .type = NLA_U32 },
+	[IFLA_GRE_OKEY]        = { .type = NLA_U32 },
+	[IFLA_GRE_LOCAL]       = { .len = sizeof_field(struct ipv6hdr, saddr) },
+	[IFLA_GRE_REMOTE]      = { .len = sizeof_field(struct ipv6hdr, daddr) },
+	[IFLA_GRE_TTL]         = { .type = NLA_U8 },
+	[IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
+	[IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
+	[IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
+	[IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
+	[IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
+	[IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
+	[IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
+	[IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
+	[IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
+	[IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
+	[IFLA_GRE_ERSPAN_VER]	= { .type = NLA_U8 },
+	[IFLA_GRE_ERSPAN_DIR]	= { .type = NLA_U8 },
+	[IFLA_GRE_ERSPAN_HWID]	= { .type = NLA_U16 },
+};
+
+static void ip6erspan_tap_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	dev->max_mtu = 0;
+	dev->netdev_ops = &ip6erspan_netdev_ops;
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = ip6gre_dev_free;
+
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	netif_keep_dst(dev);
+}
+
+static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
+			     struct nlattr *tb[], struct nlattr *data[],
+			     struct netlink_ext_ack *extack)
+{
+	struct ip6_tnl *nt = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct ip6gre_net *ign;
+	int err;
+
+	ip6gre_netlink_parms(data, &nt->parms);
+	ip6erspan_set_version(data, &nt->parms);
+	ign = net_generic(net, ip6gre_net_id);
+
+	if (nt->parms.collect_md) {
+		if (rtnl_dereference(ign->collect_md_tun_erspan))
+			return -EEXIST;
+	} else {
+		if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
+			return -EEXIST;
+	}
+
+	err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
+	if (!err) {
+		ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
+		ip6erspan_tunnel_link_md(ign, nt);
+		ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
+	}
+	return err;
+}
+
+static void ip6erspan_tnl_link_config(struct ip6_tnl *t, int set_mtu)
+{
+	ip6gre_tnl_link_config_common(t);
+	ip6gre_tnl_link_config_route(t, set_mtu, ip6erspan_calc_hlen(t));
+}
+
+static int ip6erspan_tnl_change(struct ip6_tnl *t,
+				const struct __ip6_tnl_parm *p, int set_mtu)
+{
+	ip6gre_tnl_copy_tnl_parm(t, p);
+	ip6erspan_tnl_link_config(t, set_mtu);
+	return 0;
+}
+
+static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
+				struct nlattr *data[],
+				struct netlink_ext_ack *extack)
+{
+	struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
+	struct __ip6_tnl_parm p;
+	struct ip6_tnl *t;
+
+	t = ip6gre_changelink_common(dev, tb, data, &p, extack);
+	if (IS_ERR(t))
+		return PTR_ERR(t);
+
+	ip6erspan_set_version(data, &p);
+	ip6gre_tunnel_unlink_md(ign, t);
+	ip6gre_tunnel_unlink(ign, t);
+	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
+	ip6erspan_tunnel_link_md(ign, t);
+	ip6gre_tunnel_link(ign, t);
+	return 0;
+}
+
+static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
+	.kind		= "ip6gre",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ip6gre_policy,
+	.priv_size	= sizeof(struct ip6_tnl),
+	.setup		= ip6gre_tunnel_setup,
+	.validate	= ip6gre_tunnel_validate,
+	.newlink	= ip6gre_newlink,
+	.changelink	= ip6gre_changelink,
+	.dellink	= ip6gre_dellink,
+	.get_size	= ip6gre_get_size,
+	.fill_info	= ip6gre_fill_info,
+	.get_link_net	= ip6_tnl_get_link_net,
+};
+
+static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
+	.kind		= "ip6gretap",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ip6gre_policy,
+	.priv_size	= sizeof(struct ip6_tnl),
+	.setup		= ip6gre_tap_setup,
+	.validate	= ip6gre_tap_validate,
+	.newlink	= ip6gre_newlink,
+	.changelink	= ip6gre_changelink,
+	.get_size	= ip6gre_get_size,
+	.fill_info	= ip6gre_fill_info,
+	.get_link_net	= ip6_tnl_get_link_net,
+};
+
+static struct rtnl_link_ops ip6erspan_tap_ops __read_mostly = {
+	.kind		= "ip6erspan",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ip6gre_policy,
+	.priv_size	= sizeof(struct ip6_tnl),
+	.setup		= ip6erspan_tap_setup,
+	.validate	= ip6erspan_tap_validate,
+	.newlink	= ip6erspan_newlink,
+	.changelink	= ip6erspan_changelink,
+	.get_size	= ip6gre_get_size,
+	.fill_info	= ip6gre_fill_info,
+	.get_link_net	= ip6_tnl_get_link_net,
+};
+
+/*
+ *	And now the modules code and kernel interface.
+ */
+
+static int __init ip6gre_init(void)
+{
+	int err;
+
+	pr_info("GRE over IPv6 tunneling driver\n");
+
+	err = register_pernet_device(&ip6gre_net_ops);
+	if (err < 0)
+		return err;
+
+	err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
+	if (err < 0) {
+		pr_info("%s: can't add protocol\n", __func__);
+		goto add_proto_failed;
+	}
+
+	err = rtnl_link_register(&ip6gre_link_ops);
+	if (err < 0)
+		goto rtnl_link_failed;
+
+	err = rtnl_link_register(&ip6gre_tap_ops);
+	if (err < 0)
+		goto tap_ops_failed;
+
+	err = rtnl_link_register(&ip6erspan_tap_ops);
+	if (err < 0)
+		goto erspan_link_failed;
+
+out:
+	return err;
+
+erspan_link_failed:
+	rtnl_link_unregister(&ip6gre_tap_ops);
+tap_ops_failed:
+	rtnl_link_unregister(&ip6gre_link_ops);
+rtnl_link_failed:
+	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
+add_proto_failed:
+	unregister_pernet_device(&ip6gre_net_ops);
+	goto out;
+}
+
+static void __exit ip6gre_fini(void)
+{
+	rtnl_link_unregister(&ip6gre_tap_ops);
+	rtnl_link_unregister(&ip6gre_link_ops);
+	rtnl_link_unregister(&ip6erspan_tap_ops);
+	inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
+	unregister_pernet_device(&ip6gre_net_ops);
+}
+
+module_init(ip6gre_init);
+module_exit(ip6gre_fini);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
+MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
+MODULE_ALIAS_RTNL_LINK("ip6gre");
+MODULE_ALIAS_RTNL_LINK("ip6gretap");
+MODULE_ALIAS_RTNL_LINK("ip6erspan");
+MODULE_ALIAS_NETDEV("ip6gre0");