[ovs-dev] [PATCH 3/4] Upstream IP_GRE: Refactor code GRE code.

[Pravin B Shelar]

Following patch refactors GRE code into ip tunneling code and GRE
specific code.
Goal of this work is to reuse ip-tunneling part in other tunneling
implementations. E.g. code related to device management, packet rx/tx .

Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
---
 include/net/ipip.h   |   81 +++-
 net/ipv4/Kconfig     |    5 +
 net/ipv4/Makefile    |    1 +
 net/ipv4/ip_gre.c    | 1703 ++++++++------------------------------------------
 net/ipv4/ip_tunnel.c | 1333 +++++++++++++++++++++++++++++++++++++++
 net/ipv4/ipip.c      |    9 -
 net/ipv6/sit.c       |    9 -
 7 files changed, 1673 insertions(+), 1468 deletions(-)
 create mode 100644 net/ipv4/ip_tunnel.c

diff --git a/include/net/ipip.h b/include/net/ipip.h
index 7de2500..e1940a9 100644
--- a/include/net/ipip.h
+++ b/include/net/ipip.h
@@ -26,7 +26,7 @@ struct ip_tunnel {
 	/* These four fields used only by GRE */
 	__u32			i_seqno;	/* The last seen seqno	*/
 	__u32			o_seqno;	/* The last output seqno */
-	int			hlen;		/* Precalculated GRE header length */
+	int			hlen;		/* Precalculated header length */
 	int			mlink;
 
 	struct ip_tunnel_parm	parms;
@@ -37,10 +37,14 @@ struct ip_tunnel {
 #endif
 	struct ip_tunnel_prl_entry __rcu *prl;		/* potential router list */
 	unsigned int			prl_count;	/* # of entries in PRL */
-
+	int ipt_net_id;
 	struct gro_cells		gro_cells;
 };
 
+#define TUNNEL_CSUM        __cpu_to_be16(0x8000)
+#define TUNNEL_KEY         __cpu_to_be16(0x2000)
+#define TUNNEL_SEQ         __cpu_to_be16(0x1000)
+
 struct tnl_ptk_info {
 	__be16 flags;
 	__be16 proto;
@@ -78,4 +82,77 @@ struct ip_tunnel_prl_entry {
 
 #define IPTUNNEL_XMIT() __IPTUNNEL_XMIT(txq, stats)
 
+#define HASH_SIZE  16
+struct ip_tunnel_ops {
+	char kind[IFNAMSIZ];
+	void (*parse_netlink_parms)(struct nlattr *data[],
+				    struct ip_tunnel_parm *parms);
+	int (*get_ioctl_param)(struct net_device *dev,
+			       struct ifreq *ifr,
+			       struct ip_tunnel_parm *p);
+};
+
+struct ip_tunnel_net {
+	struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
+	struct net_device *fb_tunnel_dev;
+	const struct ip_tunnel_ops *ops;
+};
+struct pcpu_tstats {
+	u64	rx_packets;
+	u64	rx_bytes;
+	u64	tx_packets;
+	u64	tx_bytes;
+	struct u64_stats_sync	syncp;
+};
+
+int ip_tunnel_init(struct net_device *dev);
+void ip_tunnel_uninit(struct net_device *dev);
+void ip_tunnel_dev_free(struct net_device *dev);
+int __net_init ip_tunnel_init_fb(struct net *net, int ipt_net_id,
+				 struct rtnl_link_ops *ops,
+				const struct net_device_ops *dev_ops,
+				char *devname);
+
+void __net_exit ip_tunnel_delete_fb(struct ip_tunnel_net *itn);
+
+void ip_tunnel_err(struct ip_tunnel *t, struct sk_buff *skb, u32 info);
+int ip_tunnel_xmit(struct sk_buff *skb,
+	const struct iphdr *tiph, const struct tnl_ptk_info *tpi,
+	void (*update_header)(struct sk_buff *skb, const struct tnl_ptk_info *tpi));
+int  ip_tunnel_build_iphdr(struct sk_buff *skb, struct net_device *dev,
+			   const struct iphdr *tiph, int hlen,
+			   struct iphdr  *niph);
+int ip_tunnel_bind_dev(struct net_device *dev);
+int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
+int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
+
+struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
+						struct rtnl_link_stats64 *tot);
+void ip_tunnel_link(struct ip_tunnel_net *itn, struct ip_tunnel *t);
+void ip_tunnel_unlink(struct ip_tunnel_net *itn, struct ip_tunnel *t);
+struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
+				   int link, __be16 flags,
+				 __be32 remote, __be32 local,
+				   __be32 key);
+struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
+				 struct ip_tunnel_parm *parms,
+				 int type);
+
+int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
+		  const struct tnl_ptk_info *tpi, bool log_ecn_error);
+int ip_tunnel_newlink(struct net *src_net, struct net_device *dev,
+		      struct nlattr *tb[],
+		      struct nlattr *data[]);
+int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
+			 struct nlattr *data[]);
+
+int ip_tunnel_open(struct net_device *dev);
+int ip_tunnel_close(struct net_device *dev);
+
+static inline void ip_tunnel_setup(struct net_device *dev, int net_id)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	tunnel->ipt_net_id = net_id;
+}
+
 #endif
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 5a19aeb..4c8b845 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -186,9 +186,14 @@ config NET_IPGRE_DEMUX
 	 This is helper module to demultiplex GRE packets on GRE version field criteria.
 	 Required by ip_gre and pptp modules.
 
+config NET_IP_TUNNEL
+	tristate
+	default n
+
 config NET_IPGRE
 	tristate "IP: GRE tunnels over IP"
 	depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
+	select NET_IP_TUNNEL
 	help
 	  Tunneling means encapsulating data of one protocol type within
 	  another protocol and sending it over a channel that understands the
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 15ca63e..089cb9f 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -13,6 +13,7 @@ obj-y     := route.o inetpeer.o protocol.o \
 	     fib_frontend.o fib_semantics.o fib_trie.o \
 	     inet_fragment.o ping.o
 
+obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
 obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 8e1ccc2..6d74bee 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -124,1359 +124,149 @@ 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");
 
-static struct rtnl_link_ops ipgre_link_ops __read_mostly;
-static int ipgre_tunnel_init(struct net_device *dev);
-static void ipgre_tunnel_setup(struct net_device *dev);
-static int ipgre_tunnel_bind_dev(struct net_device *dev);
+static int ipgre_net_id;
+static int ipgre_tap_net_id;
 
-/* Fallback tunnel: no source, no destination, no key, no options */
-
-#define HASH_SIZE  16
-
-static int ipgre_net_id __read_mostly;
-struct ipgre_net {
-	struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
-
-	struct net_device *fb_tunnel_dev;
-};
-
-/* 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(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
-
-#define tunnels_r_l	tunnels[3]
-#define tunnels_r	tunnels[2]
-#define tunnels_l	tunnels[1]
-#define tunnels_wc	tunnels[0]
-/*
- * Locking : hash tables are protected by RCU and RTNL
- */
-
-#define for_each_ip_tunnel_rcu(start) \
-	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
-
-/* often modified stats are per cpu, other are shared (netdev->stats) */
-struct pcpu_tstats {
-	u64	rx_packets;
-	u64	rx_bytes;
-	u64	tx_packets;
-	u64	tx_bytes;
-	struct u64_stats_sync	syncp;
-};
-
-static struct rtnl_link_stats64 *ipgre_get_stats64(struct net_device *dev,
-						   struct rtnl_link_stats64 *tot)
-{
-	int i;
-
-	for_each_possible_cpu(i) {
-		const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
-		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
-		unsigned int start;
-
-		do {
-			start = u64_stats_fetch_begin_bh(&tstats->syncp);
-			rx_packets = tstats->rx_packets;
-			tx_packets = tstats->tx_packets;
-			rx_bytes = tstats->rx_bytes;
-			tx_bytes = tstats->tx_bytes;
-		} while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
-
-		tot->rx_packets += rx_packets;
-		tot->tx_packets += tx_packets;
-		tot->rx_bytes   += rx_bytes;
-		tot->tx_bytes   += tx_bytes;
-	}
-
-	tot->multicast = dev->stats.multicast;
-	tot->rx_crc_errors = dev->stats.rx_crc_errors;
-	tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
-	tot->rx_length_errors = dev->stats.rx_length_errors;
-	tot->rx_frame_errors = dev->stats.rx_frame_errors;
-	tot->rx_errors = dev->stats.rx_errors;
-
-	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
-	tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
-	tot->tx_dropped = dev->stats.tx_dropped;
-	tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
-	tot->tx_errors = dev->stats.tx_errors;
-
-	return tot;
-}
-
-/* Does key in tunnel parameters match packet */
-static bool ipgre_key_match(const struct ip_tunnel_parm *p,
-			    __be16 flags, __be32 key)
-{
-	if (p->i_flags & GRE_KEY) {
-		if (flags & GRE_KEY)
-			return key == p->i_key;
-		else
-			return false;	/* key expected, none present */
-	} else
-		return !(flags & GRE_KEY);
-}
-
-/* Given src, dst and key, find appropriate for input tunnel. */
-
-static struct ip_tunnel *ipgre_tunnel_lookup(struct net_device *dev,
-					     __be32 remote, __be32 local,
-					     __be16 flags, __be32 key,
-					     __be16 gre_proto)
-{
-	struct net *net = dev_net(dev);
-	int link = dev->ifindex;
-	unsigned int h0 = HASH(remote);
-	unsigned int h1 = HASH(key);
-	struct ip_tunnel *t, *cand = NULL;
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-	int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
-		       ARPHRD_ETHER : ARPHRD_IPGRE;
-	int score, cand_score = 4;
-
-	for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
-		if (local != t->parms.iph.saddr ||
-		    remote != t->parms.iph.daddr ||
-		    !(t->dev->flags & IFF_UP))
-			continue;
-
-		if (!ipgre_key_match(&t->parms, flags, key))
-			continue;
-
-		if (t->dev->type != ARPHRD_IPGRE &&
-		    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(ign->tunnels_r[h0 ^ h1]) {
-		if (remote != t->parms.iph.daddr ||
-		    !(t->dev->flags & IFF_UP))
-			continue;
-
-		if (!ipgre_key_match(&t->parms, flags, key))
-			continue;
-
-		if (t->dev->type != ARPHRD_IPGRE &&
-		    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(ign->tunnels_l[h1]) {
-		if ((local != t->parms.iph.saddr &&
-		     (local != t->parms.iph.daddr ||
-		      !ipv4_is_multicast(local))) ||
-		    !(t->dev->flags & IFF_UP))
-			continue;
-
-		if (!ipgre_key_match(&t->parms, flags, key))
-			continue;
-
-		if (t->dev->type != ARPHRD_IPGRE &&
-		    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(ign->tunnels_wc[h1]) {
-		if (t->parms.i_key != key ||
-		    !(t->dev->flags & IFF_UP))
-			continue;
-
-		if (t->dev->type != ARPHRD_IPGRE &&
-		    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 != NULL)
-		return cand;
-
-	dev = ign->fb_tunnel_dev;
-	if (dev->flags & IFF_UP)
-		return netdev_priv(dev);
-
-	return NULL;
-}
-
-static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
-		struct ip_tunnel_parm *parms)
-{
-	__be32 remote = parms->iph.daddr;
-	__be32 local = parms->iph.saddr;
-	__be32 key = parms->i_key;
-	unsigned int h = HASH(key);
-	int prio = 0;
-
-	if (local)
-		prio |= 1;
-	if (remote && !ipv4_is_multicast(remote)) {
-		prio |= 2;
-		h ^= HASH(remote);
-	}
-
-	return &ign->tunnels[prio][h];
-}
-
-static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
-		struct ip_tunnel *t)
-{
-	return __ipgre_bucket(ign, &t->parms);
-}
-
-static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
-{
-	struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
-
-	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
-	rcu_assign_pointer(*tp, t);
-}
-
-static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
-{
-	struct ip_tunnel __rcu **tp;
-	struct ip_tunnel *iter;
-
-	for (tp = ipgre_bucket(ign, t);
-	     (iter = rtnl_dereference(*tp)) != NULL;
-	     tp = &iter->next) {
-		if (t == iter) {
-			rcu_assign_pointer(*tp, t->next);
-			break;
-		}
-	}
-}
-
-static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
-					   struct ip_tunnel_parm *parms,
-					   int type)
+static int ipgre_err(struct sk_buff *skb, u32 info,
+		     const struct tnl_ptk_info *tpi)
 {
-	__be32 remote = parms->iph.daddr;
-	__be32 local = parms->iph.saddr;
-	__be32 key = parms->i_key;
-	int link = parms->link;
-	struct ip_tunnel *t;
-	struct ip_tunnel __rcu **tp;
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-	for (tp = __ipgre_bucket(ign, parms);
-	     (t = rtnl_dereference(*tp)) != NULL;
-	     tp = &t->next)
-		if (local == t->parms.iph.saddr &&
-		    remote == t->parms.iph.daddr &&
-		    key == t->parms.i_key &&
-		    link == t->parms.link &&
-		    type == t->dev->type)
-			break;
-
-	return t;
-}
-
-static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
-		struct ip_tunnel_parm *parms, int create)
-{
-	struct ip_tunnel *t, *nt;
-	struct net_device *dev;
-	char name[IFNAMSIZ];
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-	t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
-	if (t || !create)
-		return t;
-
-	if (parms->name[0])
-		strlcpy(name, parms->name, IFNAMSIZ);
-	else
-		strcpy(name, "gre%d");
-
-	dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
-	if (!dev)
-		return NULL;
-
-	dev_net_set(dev, net);
-
-	nt = netdev_priv(dev);
-	nt->parms = *parms;
-	dev->rtnl_link_ops = &ipgre_link_ops;
-
-	dev->mtu = ipgre_tunnel_bind_dev(dev);
-
-	if (register_netdevice(dev) < 0)
-		goto failed_free;
-
-	/* Can use a lockless transmit, unless we generate output sequences */
-	if (!(nt->parms.o_flags & GRE_SEQ))
-		dev->features |= NETIF_F_LLTX;
-
-	dev_hold(dev);
-	ipgre_tunnel_link(ign, nt);
-	return nt;
-
-failed_free:
-	free_netdev(dev);
-	return NULL;
-}
-
-static void ipgre_tunnel_uninit(struct net_device *dev)
-{
-	struct net *net = dev_net(dev);
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-	ipgre_tunnel_unlink(ign, netdev_priv(dev));
-	dev_put(dev);
-}
-
-
-static void ipgre_err(struct sk_buff *skb, u32 info)
-{
-
-/* All the routers (except for Linux) return only
-   8 bytes of packet payload. It means, that precise relaying of
-   ICMP in the real Internet is absolutely infeasible.
-
-   Moreover, Cisco "wise men" put GRE key to the third word
-   in GRE header. It makes impossible maintaining even soft state for keyed
-   GRE tunnels with enabled checksum. Tell them "thank you".
-
-   Well, I wonder, rfc1812 was written by Cisco employee,
-   what the hell these idiots break standards established
-   by themselves???
- */
-
+	struct net *net = dev_net(skb->dev);
+	struct ip_tunnel_net *itn;
 	const struct iphdr *iph = (const struct iphdr *)skb->data;
-	__be16	     *p = (__be16 *)(skb->data+(iph->ihl<<2));
-	int grehlen = (iph->ihl<<2) + 4;
-	const int type = icmp_hdr(skb)->type;
-	const int code = icmp_hdr(skb)->code;
 	struct ip_tunnel *t;
-	__be16 flags;
-	__be32 key = 0;
-
-	flags = p[0];
-	if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
-		if (flags&(GRE_VERSION|GRE_ROUTING))
-			return;
-		if (flags&GRE_KEY) {
-			grehlen += 4;
-			if (flags&GRE_CSUM)
-				grehlen += 4;
-		}
-	}
+	int dev_type;
 
-	/* If only 8 bytes returned, keyed message will be dropped here */
-	if (skb_headlen(skb) < grehlen)
-		return;
-
-	if (flags & GRE_KEY)
-		key = *(((__be32 *)p) + (grehlen / 4) - 1);
-
-	switch (type) {
-	default:
-	case ICMP_PARAMETERPROB:
-		return;
-
-	case ICMP_DEST_UNREACH:
-		switch (code) {
-		case ICMP_SR_FAILED:
-		case ICMP_PORT_UNREACH:
-			/* Impossible event. */
-			return;
-		default:
-			/* All others are translated to HOST_UNREACH.
-			   rfc2003 contains "deep thoughts" about NET_UNREACH,
-			   I believe they are just ether pollution. --ANK
-			 */
-			break;
-		}
-		break;
-	case ICMP_TIME_EXCEEDED:
-		if (code != ICMP_EXC_TTL)
-			return;
-		break;
-
-	case ICMP_REDIRECT:
-		break;
+	if (tpi->proto == htons(ETH_P_TEB)) {
+		dev_type = ARPHRD_ETHER;
+		itn = net_generic(net, ipgre_tap_net_id);
+	} else {
+		dev_type = ARPHRD_IPGRE;
+		itn = net_generic(net, ipgre_net_id);
 	}
-
-	t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
-				flags, key, p[1]);
-
+	t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+			      iph->daddr, iph->saddr, tpi->key);
 	if (t == NULL)
-		return;
+		return 1;
 
-	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
-		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
-				 t->parms.link, 0, IPPROTO_GRE, 0);
-		return;
-	}
-	if (type == ICMP_REDIRECT) {
-		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
-			      IPPROTO_GRE, 0);
-		return;
-	}
-	if (t->parms.iph.daddr == 0 ||
-	    ipv4_is_multicast(t->parms.iph.daddr))
-		return;
+	ip_tunnel_err(t, skb, info);
 
-	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
-		return;
-
-	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
-		t->err_count++;
-	else
-		t->err_count = 1;
-	t->err_time = jiffies;
-}
-
-static inline u8
-ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
-{
-	u8 inner = 0;
-	if (skb->protocol == htons(ETH_P_IP))
-		inner = old_iph->tos;
-	else if (skb->protocol == htons(ETH_P_IPV6))
-		inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
-	return INET_ECN_encapsulate(tos, inner);
+	return 0;
 }
 
-static int ipgre_rcv(struct sk_buff *skb)
+static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 {
+	struct net *net = dev_net(skb->dev);
+	struct ip_tunnel_net *itn;
 	const struct iphdr *iph;
-	u8     *h;
-	__be16    flags;
-	__sum16   csum = 0;
-	__be32 key = 0;
-	u32    seqno = 0;
 	struct ip_tunnel *tunnel;
-	int    offset = 4;
-	__be16 gre_proto;
-	int    err;
+	int dev_type;
+	int err;
 
-	if (!pskb_may_pull(skb, 16))
-		goto drop;
+	if (!pskb_may_pull(skb, 16)) {
+		kfree_skb(skb);
+		return -1;
+	}
 
 	iph = ip_hdr(skb);
-	h = skb->data;
-	flags = *(__be16 *)h;
-
-	if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
-		/* - Version must be 0.
-		   - We do not support routing headers.
-		 */
-		if (flags&(GRE_VERSION|GRE_ROUTING))
-			goto drop;
-
-		if (flags&GRE_CSUM) {
-			switch (skb->ip_summed) {
-			case CHECKSUM_COMPLETE:
-				csum = csum_fold(skb->csum);
-				if (!csum)
-					break;
-				/* fall through */
-			case CHECKSUM_NONE:
-				skb->csum = 0;
-				csum = __skb_checksum_complete(skb);
-				skb->ip_summed = CHECKSUM_COMPLETE;
-			}
-			offset += 4;
-		}
-		if (flags&GRE_KEY) {
-			key = *(__be32 *)(h + offset);
-			offset += 4;
-		}
-		if (flags&GRE_SEQ) {
-			seqno = ntohl(*(__be32 *)(h + offset));
-			offset += 4;
-		}
+	if (tpi->proto == htons(ETH_P_TEB)) {
+		dev_type = ARPHRD_ETHER;
+		itn = net_generic(net, ipgre_tap_net_id);
+	} else {
+		dev_type = ARPHRD_IPGRE;
+		itn = net_generic(net, ipgre_net_id);
 	}
 
-	gre_proto = *(__be16 *)(h + 2);
-
-	tunnel = ipgre_tunnel_lookup(skb->dev,
-				     iph->saddr, iph->daddr, flags, key,
-				     gre_proto);
-	if (tunnel) {
-		struct pcpu_tstats *tstats;
-
-		secpath_reset(skb);
-
-		skb->protocol = gre_proto;
-		/* WCCP version 1 and 2 protocol decoding.
-		 * - Change protocol to IP
-		 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
-		 */
-		if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
-			skb->protocol = htons(ETH_P_IP);
-			if ((*(h + offset) & 0xF0) != 0x40)
-				offset += 4;
-		}
-
-		skb->mac_header = skb->network_header;
-		__pskb_pull(skb, offset);
-		skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
-		skb->pkt_type = PACKET_HOST;
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-		if (ipv4_is_multicast(iph->daddr)) {
-			/* Looped back packet, drop it! */
-			if (rt_is_output_route(skb_rtable(skb)))
-				goto drop;
-			tunnel->dev->stats.multicast++;
-			skb->pkt_type = PACKET_BROADCAST;
-		}
-#endif
-
-		if (((flags&GRE_CSUM) && csum) ||
-		    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
-			tunnel->dev->stats.rx_crc_errors++;
-			tunnel->dev->stats.rx_errors++;
-			goto drop;
-		}
-		if (tunnel->parms.i_flags&GRE_SEQ) {
-			if (!(flags&GRE_SEQ) ||
-			    (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
-				tunnel->dev->stats.rx_fifo_errors++;
-				tunnel->dev->stats.rx_errors++;
-				goto drop;
-			}
-			tunnel->i_seqno = seqno + 1;
-		}
-
-		/* Warning: All skb pointers will be invalidated! */
-		if (tunnel->dev->type == ARPHRD_ETHER) {
-			if (!pskb_may_pull(skb, ETH_HLEN)) {
-				tunnel->dev->stats.rx_length_errors++;
-				tunnel->dev->stats.rx_errors++;
-				goto drop;
-			}
-
-			iph = ip_hdr(skb);
-			skb->protocol = eth_type_trans(skb, tunnel->dev);
-			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
-		}
-
-		__skb_tunnel_rx(skb, tunnel->dev);
-
-		skb_reset_network_header(skb);
-		err = IP_ECN_decapsulate(iph, skb);
-		if (unlikely(err)) {
-			if (log_ecn_error)
-				net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
-						     &iph->saddr, iph->tos);
-			if (err > 1) {
-				++tunnel->dev->stats.rx_frame_errors;
-				++tunnel->dev->stats.rx_errors;
-				goto drop;
-			}
-		}
-
-		tstats = this_cpu_ptr(tunnel->dev->tstats);
-		u64_stats_update_begin(&tstats->syncp);
-		tstats->rx_packets++;
-		tstats->rx_bytes += skb->len;
-		u64_stats_update_end(&tstats->syncp);
-
-		gro_cells_receive(&tunnel->gro_cells, skb);
-		return 0;
-	}
-	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+	tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+					iph->saddr, iph->daddr, tpi->key);
+	if (tunnel)
+		err = ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);
+	else
+		err = 1;
 
-drop:
-	kfree_skb(skb);
-	return 0;
+	return err;
 }
 
-static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb,
+				     struct net_device *dev)
 {
+	__be16 proto = skb->dev->type == ARPHRD_ETHER ?
+			htons(ETH_P_TEB) : skb->protocol;
 	struct ip_tunnel *tunnel = netdev_priv(dev);
-	struct pcpu_tstats *tstats;
-	const struct iphdr  *old_iph = ip_hdr(skb);
+	struct tnl_ptk_info tpi;
 	const struct iphdr  *tiph;
-	struct flowi4 fl4;
-	u8     tos;
-	__be16 df;
-	struct rtable *rt;     			/* Route to the other host */
-	struct net_device *tdev;		/* Device to other host */
-	struct iphdr  *iph;			/* Our new IP header */
-	unsigned int max_headroom;		/* The extra header space needed */
+	struct iphdr iph;
 	int    gre_hlen;
-	__be32 dst;
-	int    mtu;
-
-	if (skb->ip_summed == CHECKSUM_PARTIAL &&
-	    skb_checksum_help(skb))
-		goto tx_error;
-
-	if (dev->type == ARPHRD_ETHER)
-		IPCB(skb)->flags = 0;
+	int err, tx_len;
 
 	if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
 		gre_hlen = 0;
 		tiph = (const struct iphdr *)skb->data;
 	} else {
-		gre_hlen = tunnel->hlen;
+		gre_hlen = tunnel->hlen + sizeof(struct iphdr);
 		tiph = &tunnel->parms.iph;
 	}
 
-	if ((dst = tiph->daddr) == 0) {
-		/* NBMA tunnel */
-
-		if (skb_dst(skb) == NULL) {
-			dev->stats.tx_fifo_errors++;
-			goto tx_error;
-		}
-
-		if (skb->protocol == htons(ETH_P_IP)) {
-			rt = skb_rtable(skb);
-			dst = rt_nexthop(rt, old_iph->daddr);
-		}
-#if IS_ENABLED(CONFIG_IPV6)
-		else if (skb->protocol == htons(ETH_P_IPV6)) {
-			const struct in6_addr *addr6;
-			struct neighbour *neigh;
-			bool do_tx_error_icmp;
-			int addr_type;
-
-			neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
-			if (neigh == NULL)
-				goto tx_error;
-
-			addr6 = (const struct in6_addr *)&neigh->primary_key;
-			addr_type = ipv6_addr_type(addr6);
-
-			if (addr_type == IPV6_ADDR_ANY) {
-				addr6 = &ipv6_hdr(skb)->daddr;
-				addr_type = ipv6_addr_type(addr6);
-			}
-
-			if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
-				do_tx_error_icmp = true;
-			else {
-				do_tx_error_icmp = false;
-				dst = addr6->s6_addr32[3];
-			}
-			neigh_release(neigh);
-			if (do_tx_error_icmp)
-				goto tx_error_icmp;
-		}
-#endif
-		else
-			goto tx_error;
-	}
-
-	tos = tiph->tos;
-	if (tos == 1) {
-		tos = 0;
-		if (skb->protocol == htons(ETH_P_IP))
-			tos = old_iph->tos;
-		else if (skb->protocol == htons(ETH_P_IPV6))
-			tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
-	}
-
-	rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
-				 tunnel->parms.o_key, RT_TOS(tos),
-				 tunnel->parms.link);
-	if (IS_ERR(rt)) {
-		dev->stats.tx_carrier_errors++;
-		goto tx_error;
-	}
-	tdev = rt->dst.dev;
-
-	if (tdev == dev) {
-		ip_rt_put(rt);
-		dev->stats.collisions++;
-		goto tx_error;
-	}
-
-	df = tiph->frag_off;
-	if (df)
-		mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
-	else
-		mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
-
-	if (skb_dst(skb))
-		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
-
-	if (skb->protocol == htons(ETH_P_IP)) {
-		df |= (old_iph->frag_off&htons(IP_DF));
-
-		if ((old_iph->frag_off&htons(IP_DF)) &&
-		    mtu < ntohs(old_iph->tot_len)) {
-			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
-			ip_rt_put(rt);
-			goto tx_error;
-		}
-	}
-#if IS_ENABLED(CONFIG_IPV6)
-	else if (skb->protocol == htons(ETH_P_IPV6)) {
-		struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
-
-		if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
-			if ((tunnel->parms.iph.daddr &&
-			     !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
-			    rt6->rt6i_dst.plen == 128) {
-				rt6->rt6i_flags |= RTF_MODIFIED;
-				dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
-			}
-		}
-
-		if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
-			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
-			ip_rt_put(rt);
-			goto tx_error;
-		}
-	}
-#endif
+	err = ip_tunnel_build_iphdr(skb, dev, tiph, gre_hlen, &iph);
+	if (err)
+		return NETDEV_TX_OK;
 
-	if (tunnel->err_count > 0) {
-		if (time_before(jiffies,
-				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
-			tunnel->err_count--;
+	tpi.flags = tunnel->parms.o_flags;
+	tpi.proto = proto;
+	tpi.key = tunnel->parms.o_key;
+	tpi.seq =  htonl(tunnel->o_seqno);
+	tpi.hdr_len = tunnel->hlen;
 
-			dst_link_failure(skb);
-		} else
-			tunnel->err_count = 0;
-	}
-
-	max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
-
-	if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
-	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
-		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
-		if (max_headroom > dev->needed_headroom)
-			dev->needed_headroom = max_headroom;
-		if (!new_skb) {
-			ip_rt_put(rt);
-			dev->stats.tx_dropped++;
-			dev_kfree_skb(skb);
-			return NETDEV_TX_OK;
-		}
-		if (skb->sk)
-			skb_set_owner_w(new_skb, skb->sk);
+	if (skb_cow_head(skb, dev->needed_headroom)) {
+		dev->stats.tx_dropped++;
 		dev_kfree_skb(skb);
-		skb = new_skb;
-		old_iph = ip_hdr(skb);
-	}
-
-	skb_reset_transport_header(skb);
-	skb_push(skb, gre_hlen);
-	skb_reset_network_header(skb);
-	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
-			      IPSKB_REROUTED);
-	skb_dst_drop(skb);
-	skb_dst_set(skb, &rt->dst);
-
-	/*
-	 *	Push down and install the IPIP header.
-	 */
-
-	iph 			=	ip_hdr(skb);
-	iph->version		=	4;
-	iph->ihl		=	sizeof(struct iphdr) >> 2;
-	iph->frag_off		=	df;
-	iph->protocol		=	IPPROTO_GRE;
-	iph->tos		=	ipgre_ecn_encapsulate(tos, old_iph, skb);
-	iph->daddr		=	fl4.daddr;
-	iph->saddr		=	fl4.saddr;
-
-	if ((iph->ttl = tiph->ttl) == 0) {
-		if (skb->protocol == htons(ETH_P_IP))
-			iph->ttl = old_iph->ttl;
-#if IS_ENABLED(CONFIG_IPV6)
-		else if (skb->protocol == htons(ETH_P_IPV6))
-			iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
-#endif
-		else
-			iph->ttl = ip4_dst_hoplimit(&rt->dst);
+		return NETDEV_TX_OK;
 	}
 
-	((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
-	((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
-				   htons(ETH_P_TEB) : skb->protocol;
+	tx_len = ip_tunnel_xmit(skb, &iph, &tpi, gre_update_header);
+	if (tx_len > 0) {
+		struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);
 
-	if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
-		__be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
+		u64_stats_update_begin(&tstats->syncp);
+		tstats->tx_bytes += tx_len;
+		tstats->tx_packets++;
+		u64_stats_update_end(&tstats->syncp);
 
-		if (tunnel->parms.o_flags&GRE_SEQ) {
+		if (tunnel->parms.o_flags&GRE_SEQ)
 			++tunnel->o_seqno;
-			*ptr = htonl(tunnel->o_seqno);
-			ptr--;
-		}
-		if (tunnel->parms.o_flags&GRE_KEY) {
-			*ptr = tunnel->parms.o_key;
-			ptr--;
-		}
-		if (tunnel->parms.o_flags&GRE_CSUM) {
-			*ptr = 0;
-			*(__sum16 *)ptr = ip_compute_csum((void *)(iph+1), skb->len - sizeof(struct iphdr));
-		}
+	} else {
+		dev->stats.tx_errors++;
+		dev->stats.tx_aborted_errors++;
 	}
 
-	nf_reset(skb);
-	tstats = this_cpu_ptr(dev->tstats);
-	__IPTUNNEL_XMIT(tstats, &dev->stats);
-	return NETDEV_TX_OK;
-
-#if IS_ENABLED(CONFIG_IPV6)
-tx_error_icmp:
-	dst_link_failure(skb);
-#endif
-tx_error:
-	dev->stats.tx_errors++;
-	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
 
-static int ipgre_tunnel_bind_dev(struct net_device *dev)
+static int ipgre_get_ioctl_param(struct net_device *dev, struct ifreq *ifr,
+				 struct ip_tunnel_parm *p)
 {
-	struct net_device *tdev = NULL;
-	struct ip_tunnel *tunnel;
-	const struct iphdr *iph;
-	int hlen = LL_MAX_HEADER;
-	int mtu = ETH_DATA_LEN;
-	int addend = sizeof(struct iphdr) + 4;
+	BUILD_BUG_ON(TUNNEL_KEY  != GRE_KEY);
+	BUILD_BUG_ON(TUNNEL_SEQ  != GRE_SEQ);
+	BUILD_BUG_ON(TUNNEL_CSUM != GRE_CSUM);
 
-	tunnel = netdev_priv(dev);
-	iph = &tunnel->parms.iph;
-
-	/* Guess output device to choose reasonable mtu and needed_headroom */
-
-	if (iph->daddr) {
-		struct flowi4 fl4;
-		struct rtable *rt;
-
-		rt = ip_route_output_gre(dev_net(dev), &fl4,
-					 iph->daddr, iph->saddr,
-					 tunnel->parms.o_key,
-					 RT_TOS(iph->tos),
-					 tunnel->parms.link);
-		if (!IS_ERR(rt)) {
-			tdev = rt->dst.dev;
-			ip_rt_put(rt);
-		}
-
-		if (dev->type != ARPHRD_ETHER)
-			dev->flags |= IFF_POINTOPOINT;
-	}
-
-	if (!tdev && tunnel->parms.link)
-		tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
-
-	if (tdev) {
-		hlen = tdev->hard_header_len + tdev->needed_headroom;
-		mtu = tdev->mtu;
-	}
-	dev->iflink = tunnel->parms.link;
-
-	/* Precalculate GRE options length */
-	if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
-		if (tunnel->parms.o_flags&GRE_CSUM)
-			addend += 4;
-		if (tunnel->parms.o_flags&GRE_KEY)
-			addend += 4;
-		if (tunnel->parms.o_flags&GRE_SEQ)
-			addend += 4;
-	}
-	dev->needed_headroom = addend + hlen;
-	mtu -= dev->hard_header_len + addend;
-
-	if (mtu < 68)
-		mtu = 68;
-
-	tunnel->hlen = addend;
+	if (copy_from_user(p, ifr->ifr_ifru.ifru_data, sizeof(*p)))
+		return -EFAULT;
 
-	return mtu;
-}
-
-static int
-ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
-{
-	int err = 0;
-	struct ip_tunnel_parm p;
-	struct ip_tunnel *t;
-	struct net *net = dev_net(dev);
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-	switch (cmd) {
-	case SIOCGETTUNNEL:
-		t = NULL;
-		if (dev == ign->fb_tunnel_dev) {
-			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
-				err = -EFAULT;
-				break;
-			}
-			t = ipgre_tunnel_locate(net, &p, 0);
-		}
-		if (t == NULL)
-			t = netdev_priv(dev);
-		memcpy(&p, &t->parms, sizeof(p));
-		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
-			err = -EFAULT;
-		break;
-
-	case SIOCADDTUNNEL:
-	case SIOCCHGTUNNEL:
-		err = -EPERM;
-		if (!capable(CAP_NET_ADMIN))
-			goto done;
-
-		err = -EFAULT;
-		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
-			goto done;
-
-		err = -EINVAL;
-		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
-		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
-		    ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
-			goto done;
-		if (p.iph.ttl)
-			p.iph.frag_off |= htons(IP_DF);
-
-		if (!(p.i_flags&GRE_KEY))
-			p.i_key = 0;
-		if (!(p.o_flags&GRE_KEY))
-			p.o_key = 0;
-
-		t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
-
-		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
-			if (t != NULL) {
-				if (t->dev != dev) {
-					err = -EEXIST;
-					break;
-				}
-			} else {
-				unsigned int nflags = 0;
-
-				t = netdev_priv(dev);
-
-				if (ipv4_is_multicast(p.iph.daddr))
-					nflags = IFF_BROADCAST;
-				else if (p.iph.daddr)
-					nflags = IFF_POINTOPOINT;
-
-				if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
-					err = -EINVAL;
-					break;
-				}
-				ipgre_tunnel_unlink(ign, t);
-				synchronize_net();
-				t->parms.iph.saddr = p.iph.saddr;
-				t->parms.iph.daddr = p.iph.daddr;
-				t->parms.i_key = p.i_key;
-				t->parms.o_key = p.o_key;
-				memcpy(dev->dev_addr, &p.iph.saddr, 4);
-				memcpy(dev->broadcast, &p.iph.daddr, 4);
-				ipgre_tunnel_link(ign, t);
-				netdev_state_change(dev);
-			}
-		}
-
-		if (t) {
-			err = 0;
-			if (cmd == SIOCCHGTUNNEL) {
-				t->parms.iph.ttl = p.iph.ttl;
-				t->parms.iph.tos = p.iph.tos;
-				t->parms.iph.frag_off = p.iph.frag_off;
-				if (t->parms.link != p.link) {
-					t->parms.link = p.link;
-					dev->mtu = ipgre_tunnel_bind_dev(dev);
-					netdev_state_change(dev);
-				}
-			}
-			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
-				err = -EFAULT;
-		} else
-			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
-		break;
-
-	case SIOCDELTUNNEL:
-		err = -EPERM;
-		if (!capable(CAP_NET_ADMIN))
-			goto done;
-
-		if (dev == ign->fb_tunnel_dev) {
-			err = -EFAULT;
-			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
-				goto done;
-			err = -ENOENT;
-			if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
-				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 ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
-{
-	struct ip_tunnel *tunnel = netdev_priv(dev);
-	if (new_mtu < 68 ||
-	    new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
+	if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
+			p->iph.ihl != 5 || (p->iph.frag_off&htons(~IP_DF)) ||
+			((p->i_flags|p->o_flags)&(GRE_VERSION|GRE_ROUTING))) {
 		return -EINVAL;
-	dev->mtu = new_mtu;
-	return 0;
-}
-
-/* Nice toy. Unfortunately, useless in real life :-)
-   It allows to construct virtual multiprotocol broadcast "LAN"
-   over the Internet, provided multicast routing is tuned.
-
-
-   I have no idea was this bicycle invented before me,
-   so that I had to set ARPHRD_IPGRE to a random value.
-   I have an impression, that Cisco could make something similar,
-   but this feature is apparently missing in IOS<=11.2(8).
-
-   I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
-   with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
-
-   ping -t 255 224.66.66.66
-
-   If nobody answers, mbone does not work.
-
-   ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
-   ip addr add 10.66.66.<somewhat>/24 dev Universe
-   ifconfig Universe up
-   ifconfig Universe add fe80::<Your_real_addr>/10
-   ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
-   ftp 10.66.66.66
-   ...
-   ftp fec0:6666:6666::193.233.7.65
-   ...
-
- */
-
-static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
-			unsigned short type,
-			const void *daddr, const void *saddr, unsigned int len)
-{
-	struct ip_tunnel *t = netdev_priv(dev);
-	struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
-	__be16 *p = (__be16 *)(iph+1);
-
-	memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
-	p[0]		= t->parms.o_flags;
-	p[1]		= htons(type);
-
-	/*
-	 *	Set the source hardware address.
-	 */
-
-	if (saddr)
-		memcpy(&iph->saddr, saddr, 4);
-	if (daddr)
-		memcpy(&iph->daddr, daddr, 4);
-	if (iph->daddr)
-		return t->hlen;
-
-	return -t->hlen;
-}
-
-static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
-{
-	const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
-	memcpy(haddr, &iph->saddr, 4);
-	return 4;
-}
-
-static const struct header_ops ipgre_header_ops = {
-	.create	= ipgre_header,
-	.parse	= ipgre_header_parse,
-};
-
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-static int ipgre_open(struct net_device *dev)
-{
-	struct ip_tunnel *t = netdev_priv(dev);
-
-	if (ipv4_is_multicast(t->parms.iph.daddr)) {
-		struct flowi4 fl4;
-		struct rtable *rt;
-
-		rt = ip_route_output_gre(dev_net(dev), &fl4,
-					 t->parms.iph.daddr,
-					 t->parms.iph.saddr,
-					 t->parms.o_key,
-					 RT_TOS(t->parms.iph.tos),
-					 t->parms.link);
-		if (IS_ERR(rt))
-			return -EADDRNOTAVAIL;
-		dev = rt->dst.dev;
-		ip_rt_put(rt);
-		if (__in_dev_get_rtnl(dev) == NULL)
-			return -EADDRNOTAVAIL;
-		t->mlink = dev->ifindex;
-		ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
 	}
-	return 0;
-}
 
-static int ipgre_close(struct net_device *dev)
-{
-	struct ip_tunnel *t = netdev_priv(dev);
+	if (p->iph.ttl)
+		p->iph.frag_off |= htons(IP_DF);
 
-	if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
-		struct in_device *in_dev;
-		in_dev = inetdev_by_index(dev_net(dev), t->mlink);
-		if (in_dev)
-			ip_mc_dec_group(in_dev, t->parms.iph.daddr);
-	}
+	if (!(p->i_flags&GRE_KEY))
+		p->i_key = 0;
+	if (!(p->o_flags&GRE_KEY))
+		p->o_key = 0;
 	return 0;
 }
 
-#endif
-
-static const struct net_device_ops ipgre_netdev_ops = {
-	.ndo_init		= ipgre_tunnel_init,
-	.ndo_uninit		= ipgre_tunnel_uninit,
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-	.ndo_open		= ipgre_open,
-	.ndo_stop		= ipgre_close,
-#endif
-	.ndo_start_xmit		= ipgre_tunnel_xmit,
-	.ndo_do_ioctl		= ipgre_tunnel_ioctl,
-	.ndo_change_mtu		= ipgre_tunnel_change_mtu,
-	.ndo_get_stats64	= ipgre_get_stats64,
-};
-
-static void ipgre_dev_free(struct net_device *dev)
-{
-	struct ip_tunnel *tunnel = netdev_priv(dev);
-
-	gro_cells_destroy(&tunnel->gro_cells);
-	free_percpu(dev->tstats);
-	free_netdev(dev);
-}
-
-#define GRE_FEATURES (NETIF_F_SG |		\
-		      NETIF_F_FRAGLIST |	\
-		      NETIF_F_HIGHDMA |		\
-		      NETIF_F_HW_CSUM)
-
-static void ipgre_tunnel_setup(struct net_device *dev)
-{
-	dev->netdev_ops		= &ipgre_netdev_ops;
-	dev->destructor 	= ipgre_dev_free;
-
-	dev->type		= ARPHRD_IPGRE;
-	dev->needed_headroom 	= LL_MAX_HEADER + sizeof(struct iphdr) + 4;
-	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 4;
-	dev->flags		= IFF_NOARP;
-	dev->iflink		= 0;
-	dev->addr_len		= 4;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
-	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
-
-	dev->features		|= GRE_FEATURES;
-	dev->hw_features	|= GRE_FEATURES;
-}
-
-static int ipgre_tunnel_init(struct net_device *dev)
-{
-	struct ip_tunnel *tunnel;
-	struct iphdr *iph;
-	int err;
-
-	tunnel = netdev_priv(dev);
-	iph = &tunnel->parms.iph;
-
-	tunnel->dev = dev;
-	strcpy(tunnel->parms.name, dev->name);
-
-	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
-	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
-
-	if (iph->daddr) {
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-		if (ipv4_is_multicast(iph->daddr)) {
-			if (!iph->saddr)
-				return -EINVAL;
-			dev->flags = IFF_BROADCAST;
-			dev->header_ops = &ipgre_header_ops;
-		}
-#endif
-	} else
-		dev->header_ops = &ipgre_header_ops;
-
-	dev->tstats = alloc_percpu(struct pcpu_tstats);
-	if (!dev->tstats)
-		return -ENOMEM;
-
-	err = gro_cells_init(&tunnel->gro_cells, dev);
-	if (err) {
-		free_percpu(dev->tstats);
-		return err;
-	}
-
-	return 0;
-}
-
-static void ipgre_fb_tunnel_init(struct net_device *dev)
-{
-	struct ip_tunnel *tunnel = netdev_priv(dev);
-	struct iphdr *iph = &tunnel->parms.iph;
-
-	tunnel->dev = dev;
-	strcpy(tunnel->parms.name, dev->name);
-
-	iph->version		= 4;
-	iph->protocol		= IPPROTO_GRE;
-	iph->ihl		= 5;
-	tunnel->hlen		= sizeof(struct iphdr) + 4;
-
-	dev_hold(dev);
-}
-
-
-static const struct gre_protocol ipgre_protocol = {
-	.handler     = ipgre_rcv,
-	.err_handler = ipgre_err,
-};
-
-static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
-{
-	int prio;
-
-	for (prio = 0; prio < 4; prio++) {
-		int h;
-		for (h = 0; h < HASH_SIZE; h++) {
-			struct ip_tunnel *t;
-
-			t = rtnl_dereference(ign->tunnels[prio][h]);
-
-			while (t != NULL) {
-				unregister_netdevice_queue(t->dev, head);
-				t = rtnl_dereference(t->next);
-			}
-		}
-	}
-}
-
-static int __net_init ipgre_init_net(struct net *net)
-{
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-	int err;
-
-	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
-					   ipgre_tunnel_setup);
-	if (!ign->fb_tunnel_dev) {
-		err = -ENOMEM;
-		goto err_alloc_dev;
-	}
-	dev_net_set(ign->fb_tunnel_dev, net);
-
-	ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
-	ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
-
-	if ((err = register_netdev(ign->fb_tunnel_dev)))
-		goto err_reg_dev;
-
-	rcu_assign_pointer(ign->tunnels_wc[0],
-			   netdev_priv(ign->fb_tunnel_dev));
-	return 0;
-
-err_reg_dev:
-	ipgre_dev_free(ign->fb_tunnel_dev);
-err_alloc_dev:
-	return err;
-}
-
-static void __net_exit ipgre_exit_net(struct net *net)
-{
-	struct ipgre_net *ign;
-	LIST_HEAD(list);
-
-	ign = net_generic(net, ipgre_net_id);
-	rtnl_lock();
-	ipgre_destroy_tunnels(ign, &list);
-	unregister_netdevice_many(&list);
-	rtnl_unlock();
-}
-
-static struct pernet_operations ipgre_net_ops = {
-	.init = ipgre_init_net,
-	.exit = ipgre_exit_net,
-	.id   = &ipgre_net_id,
-	.size = sizeof(struct ipgre_net),
-};
-
 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
 {
 	__be16 flags;
@@ -1560,146 +350,6 @@ static void ipgre_netlink_parms(struct nlattr *data[],
 		parms->iph.frag_off = htons(IP_DF);
 }
 
-static int ipgre_tap_init(struct net_device *dev)
-{
-	struct ip_tunnel *tunnel;
-
-	tunnel = netdev_priv(dev);
-
-	tunnel->dev = dev;
-	strcpy(tunnel->parms.name, dev->name);
-
-	ipgre_tunnel_bind_dev(dev);
-
-	dev->tstats = alloc_percpu(struct pcpu_tstats);
-	if (!dev->tstats)
-		return -ENOMEM;
-
-	return 0;
-}
-
-static const struct net_device_ops ipgre_tap_netdev_ops = {
-	.ndo_init		= ipgre_tap_init,
-	.ndo_uninit		= ipgre_tunnel_uninit,
-	.ndo_start_xmit		= ipgre_tunnel_xmit,
-	.ndo_set_mac_address 	= eth_mac_addr,
-	.ndo_validate_addr	= eth_validate_addr,
-	.ndo_change_mtu		= ipgre_tunnel_change_mtu,
-	.ndo_get_stats64	= ipgre_get_stats64,
-};
-
-static void ipgre_tap_setup(struct net_device *dev)
-{
-
-	ether_setup(dev);
-
-	dev->netdev_ops		= &ipgre_tap_netdev_ops;
-	dev->destructor 	= ipgre_dev_free;
-
-	dev->iflink		= 0;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
-}
-
-static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
-			 struct nlattr *data[])
-{
-	struct ip_tunnel *nt;
-	struct net *net = dev_net(dev);
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-	int mtu;
-	int err;
-
-	nt = netdev_priv(dev);
-	ipgre_netlink_parms(data, &nt->parms);
-
-	if (ipgre_tunnel_find(net, &nt->parms, dev->type))
-		return -EEXIST;
-
-	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
-		eth_hw_addr_random(dev);
-
-	mtu = ipgre_tunnel_bind_dev(dev);
-	if (!tb[IFLA_MTU])
-		dev->mtu = mtu;
-
-	/* Can use a lockless transmit, unless we generate output sequences */
-	if (!(nt->parms.o_flags & GRE_SEQ))
-		dev->features |= NETIF_F_LLTX;
-
-	err = register_netdevice(dev);
-	if (err)
-		goto out;
-
-	dev_hold(dev);
-	ipgre_tunnel_link(ign, nt);
-
-out:
-	return err;
-}
-
-static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
-			    struct nlattr *data[])
-{
-	struct ip_tunnel *t, *nt;
-	struct net *net = dev_net(dev);
-	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-	struct ip_tunnel_parm p;
-	int mtu;
-
-	if (dev == ign->fb_tunnel_dev)
-		return -EINVAL;
-
-	nt = netdev_priv(dev);
-	ipgre_netlink_parms(data, &p);
-
-	t = ipgre_tunnel_locate(net, &p, 0);
-
-	if (t) {
-		if (t->dev != dev)
-			return -EEXIST;
-	} else {
-		t = nt;
-
-		if (dev->type != ARPHRD_ETHER) {
-			unsigned int nflags = 0;
-
-			if (ipv4_is_multicast(p.iph.daddr))
-				nflags = IFF_BROADCAST;
-			else if (p.iph.daddr)
-				nflags = IFF_POINTOPOINT;
-
-			if ((dev->flags ^ nflags) &
-			    (IFF_POINTOPOINT | IFF_BROADCAST))
-				return -EINVAL;
-		}
-
-		ipgre_tunnel_unlink(ign, t);
-		t->parms.iph.saddr = p.iph.saddr;
-		t->parms.iph.daddr = p.iph.daddr;
-		t->parms.i_key = p.i_key;
-		if (dev->type != ARPHRD_ETHER) {
-			memcpy(dev->dev_addr, &p.iph.saddr, 4);
-			memcpy(dev->broadcast, &p.iph.daddr, 4);
-		}
-		ipgre_tunnel_link(ign, t);
-		netdev_state_change(dev);
-	}
-
-	t->parms.o_key = p.o_key;
-	t->parms.iph.ttl = p.iph.ttl;
-	t->parms.iph.tos = p.iph.tos;
-	t->parms.iph.frag_off = p.iph.frag_off;
-
-	if (t->parms.link != p.link) {
-		t->parms.link = p.link;
-		mtu = ipgre_tunnel_bind_dev(dev);
-		if (!tb[IFLA_MTU])
-			dev->mtu = mtu;
-		netdev_state_change(dev);
-	}
-
-	return 0;
-}
 
 static size_t ipgre_get_size(const struct net_device *dev)
 {
@@ -1763,6 +413,75 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
 	[IFLA_GRE_PMTUDISC]	= { .type = NLA_U8 },
 };
 
+static int ip_gre_calc_hlen(struct ip_tunnel *tunnel)
+{
+	int addend = 4;
+
+	/* Precalculate GRE options length */
+	if (tunnel->parms.o_flags&GRE_CSUM)
+		addend += 4;
+	if (tunnel->parms.o_flags&GRE_KEY)
+		addend += 4;
+	if (tunnel->parms.o_flags&GRE_SEQ)
+		addend += 4;
+	return addend;
+}
+
+#define GRE_FEATURES (NETIF_F_SG |		\
+		      NETIF_F_FRAGLIST |	\
+		      NETIF_F_HIGHDMA |		\
+		      NETIF_F_HW_CSUM)
+
+static void __gre_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel;
+
+	tunnel = netdev_priv(dev);
+	tunnel->hlen = ip_gre_calc_hlen(tunnel);
+	tunnel->parms.iph.protocol = IPPROTO_GRE;
+
+	dev->needed_headroom	= LL_MAX_HEADER + sizeof(struct iphdr) + 4;
+	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 4;
+	dev->iflink		= 0;
+
+	dev->features		|= NETIF_F_NETNS_LOCAL | GRE_FEATURES;
+	dev->hw_features	|= GRE_FEATURES;
+}
+
+static int ipgre_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+
+	__gre_tunnel_init(dev);
+
+	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+
+	dev->type		= ARPHRD_IPGRE;
+	dev->flags		= IFF_NOARP;
+	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
+	dev->addr_len		= 4;
+
+	return ip_tunnel_init(dev);
+}
+
+static int ipgre_tap_init(struct net_device *dev)
+{
+	__gre_tunnel_init(dev);
+	return ip_tunnel_init(dev);
+}
+
+static inline void ipgre_tap_tunnel_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+	ip_tunnel_setup(dev, ipgre_tap_net_id);
+}
+
+static inline void ipgre_tunnel_setup(struct net_device *dev)
+{
+	ip_tunnel_setup(dev, ipgre_net_id);
+}
+
 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
 	.kind		= "gre",
 	.maxtype	= IFLA_GRE_MAX,
@@ -1770,8 +489,8 @@ static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
 	.priv_size	= sizeof(struct ip_tunnel),
 	.setup		= ipgre_tunnel_setup,
 	.validate	= ipgre_tunnel_validate,
-	.newlink	= ipgre_newlink,
-	.changelink	= ipgre_changelink,
+	.newlink	= ip_tunnel_newlink,
+	.changelink	= ip_tunnel_changelink,
 	.get_size	= ipgre_get_size,
 	.fill_info	= ipgre_fill_info,
 };
@@ -1781,17 +500,97 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
 	.maxtype	= IFLA_GRE_MAX,
 	.policy		= ipgre_policy,
 	.priv_size	= sizeof(struct ip_tunnel),
-	.setup		= ipgre_tap_setup,
+	.setup		= ipgre_tap_tunnel_setup,
 	.validate	= ipgre_tap_validate,
-	.newlink	= ipgre_newlink,
-	.changelink	= ipgre_changelink,
+	.newlink	= ip_tunnel_newlink,
+	.changelink	= ip_tunnel_changelink,
 	.get_size	= ipgre_get_size,
 	.fill_info	= ipgre_fill_info,
 };
 
-/*
- *	And now the modules code and kernel interface.
- */
+static const struct net_device_ops ipgre_netdev_ops = {
+	.ndo_init		= ipgre_tunnel_init,
+	.ndo_uninit		= ip_tunnel_uninit,
+	.ndo_start_xmit		= ipgre_tunnel_xmit,
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+	.ndo_open		= ip_tunnel_open,
+	.ndo_stop		= ip_tunnel_close,
+#endif
+	.ndo_do_ioctl		= ip_tunnel_ioctl,
+	.ndo_change_mtu		= ip_tunnel_change_mtu,
+	.ndo_get_stats64	= ip_tunnel_get_stats64,
+};
+
+static const struct net_device_ops ipgre_tap_netdev_ops = {
+	.ndo_init		= ipgre_tap_init,
+	.ndo_uninit		= ip_tunnel_uninit,
+	.ndo_start_xmit		= ipgre_tunnel_xmit,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_change_mtu		= ip_tunnel_change_mtu,
+	.ndo_get_stats64	= ip_tunnel_get_stats64,
+};
+
+static const struct ip_tunnel_ops ipgre_tunnel_ops = {
+	.kind	= "gre",
+	.parse_netlink_parms = ipgre_netlink_parms,
+	.get_ioctl_param = ipgre_get_ioctl_param,
+};
+
+static int __net_init ipgre_init_net(struct net *net)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
+
+	itn->ops = &ipgre_tunnel_ops;
+	return ip_tunnel_init_fb(net, ipgre_net_id,
+				 &ipgre_link_ops, &ipgre_netdev_ops, "gre0");
+}
+
+static void __net_exit ipgre_exit_net(struct net *net)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
+	ip_tunnel_delete_fb(itn);
+}
+
+static struct pernet_operations ipgre_net_ops = {
+	.init = ipgre_init_net,
+	.exit = ipgre_exit_net,
+	.id   = &ipgre_net_id,
+	.size = sizeof(struct ip_tunnel_net),
+};
+
+static const struct ip_tunnel_ops ipgre_tap_tunnel_ops = {
+	.kind	= "gretap",
+	.parse_netlink_parms = ipgre_netlink_parms,
+	.get_ioctl_param = ipgre_get_ioctl_param,
+};
+
+static int __net_init ipgre_tap_init_net(struct net *net)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipgre_tap_net_id);
+
+	itn->ops = &ipgre_tap_tunnel_ops;
+	return ip_tunnel_init_fb(net, ipgre_tap_net_id,
+			 &ipgre_tap_ops, &ipgre_tap_netdev_ops, "gretap0");
+}
+
+static void __net_exit ipgre_tap_exit_net(struct net *net)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipgre_tap_net_id);
+	ip_tunnel_delete_fb(itn);
+}
+
+static struct pernet_operations ipgre_tap_net_ops = {
+	.init = ipgre_tap_init_net,
+	.exit = ipgre_tap_exit_net,
+	.id   = &ipgre_tap_net_id,
+	.size = sizeof(struct ip_tunnel_net),
+};
+
+static const struct gre_protocol_v0 ipgre_protocol = {
+	.handler     = ipgre_rcv,
+	.err_handler = ipgre_err,
+};
 
 static int __init ipgre_init(void)
 {
@@ -1803,8 +602,12 @@ static int __init ipgre_init(void)
 	if (err < 0)
 		return err;
 
+	err = register_pernet_device(&ipgre_tap_net_ops);
+	if (err < 0)
+		goto pnet_tap_faied;
+
 	rtnl_lock();
-	err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
+	err = gre_add_protocol_v0(&ipgre_protocol, GREPROTO_CISCO);
 	if (err < 0) {
 		rtnl_unlock();
 		pr_info("%s: can't add protocol\n", __func__);
@@ -1826,8 +629,10 @@ out:
 tap_ops_failed:
 	rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
-	gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
+	gre_del_protocol_v0(&ipgre_protocol, 0);
 add_proto_failed:
+	unregister_pernet_device(&ipgre_tap_net_ops);
+pnet_tap_faied:
 	unregister_pernet_device(&ipgre_net_ops);
 	goto out;
 }
@@ -1837,9 +642,11 @@ static void __exit ipgre_fini(void)
 	rtnl_link_unregister(&ipgre_tap_ops);
 	rtnl_link_unregister(&ipgre_link_ops);
 	rtnl_lock();
-	if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
-		pr_info("%s: can't remove protocol\n", __func__);
+	if (gre_del_protocol_v0(&ipgre_protocol, 0) < 0)
+ 		pr_info("%s: can't remove protocol\n", __func__);
 	rtnl_unlock();
+	unregister_pernet_device(&ipgre_tap_net_ops);
+
 	unregister_pernet_device(&ipgre_net_ops);
 }
 
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
new file mode 100644
index 0000000..524f002
--- /dev/null
+++ b/net/ipv4/ip_tunnel.c
@@ -0,0 +1,1333 @@
+/*
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/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/mroute.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 <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/ipip.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>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#endif
+
+/* Fallback tunnel: no source, no destination, no key, no options */
+
+
+/* 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(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+
+#define tunnels_r_l	tunnels[3]
+#define tunnels_r	tunnels[2]
+#define tunnels_l	tunnels[1]
+#define tunnels_wc	tunnels[0]
+/*
+ * Locking : hash tables are protected by RCU and RTNL
+ */
+
+#define for_each_ip_tunnel_rcu(start) \
+	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
+
+/* often modified stats are per cpu, other are shared (netdev->stats) */
+struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
+					   struct rtnl_link_stats64 *tot)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
+		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
+		unsigned int start;
+
+		do {
+			start = u64_stats_fetch_begin_bh(&tstats->syncp);
+			rx_packets = tstats->rx_packets;
+			tx_packets = tstats->tx_packets;
+			rx_bytes = tstats->rx_bytes;
+			tx_bytes = tstats->tx_bytes;
+		} while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
+
+		tot->rx_packets += rx_packets;
+		tot->tx_packets += tx_packets;
+		tot->rx_bytes   += rx_bytes;
+		tot->tx_bytes   += tx_bytes;
+	}
+
+	tot->multicast = dev->stats.multicast;
+	tot->rx_crc_errors = dev->stats.rx_crc_errors;
+	tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
+	tot->rx_length_errors = dev->stats.rx_length_errors;
+	tot->rx_frame_errors = dev->stats.rx_frame_errors;
+	tot->rx_errors = dev->stats.rx_errors;
+	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
+	tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
+	tot->tx_dropped = dev->stats.tx_dropped;
+	tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
+	tot->tx_errors = dev->stats.tx_errors;
+
+	return tot;
+}
+EXPORT_SYMBOL(ip_tunnel_get_stats64);
+
+static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p,
+				__be16 flags, __be32 key)
+{
+	if (p->i_flags & TUNNEL_KEY) {
+		if (flags & TUNNEL_KEY)
+			return key == p->i_key;
+		else
+			return false;   /* key expected, none present */
+	} else
+		return !(flags & TUNNEL_KEY);
+}
+
+/* Given src, dst and key, find appropriate for input tunnel. */
+struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
+				    int link, __be16 flags,
+				    __be32 remote, __be32 local,
+				    __be32 key)
+{
+	unsigned int h0 = HASH(remote);
+	unsigned int h1 = HASH(key);
+	struct ip_tunnel *t, *cand = NULL;
+
+	for_each_ip_tunnel_rcu(itn->tunnels_r_l[h0 ^ h1]) {
+		if (local != t->parms.iph.saddr ||
+		    remote != t->parms.iph.daddr ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (!ip_tunnel_key_match(&t->parms, flags, key))
+			continue;
+
+		if (t->parms.link == link)
+			return t;
+		else
+			cand = t;
+	}
+
+	for_each_ip_tunnel_rcu(itn->tunnels_r[h0 ^ h1]) {
+		if (remote != t->parms.iph.daddr ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (!ip_tunnel_key_match(&t->parms, flags, key))
+			continue;
+
+		if (t->parms.link == link)
+			return t;
+		else {
+			if (!cand)
+				cand = t;
+		}
+	}
+
+	for_each_ip_tunnel_rcu(itn->tunnels_l[h1]) {
+		if ((local != t->parms.iph.saddr &&
+		     (local != t->parms.iph.daddr ||
+		      !ipv4_is_multicast(local))) ||
+		    key != t->parms.i_key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (!ip_tunnel_key_match(&t->parms, flags, key))
+			continue;
+
+		if (t->parms.link == link)
+			return t;
+		else {
+			if (!cand)
+				cand = t;
+		}
+	}
+
+	for_each_ip_tunnel_rcu(itn->tunnels_wc[h1]) {
+		if (t->parms.i_key != key ||
+		    !(t->dev->flags & IFF_UP))
+			continue;
+
+		if (!ip_tunnel_key_match(&t->parms, flags, key))
+			continue;
+
+		if (t->parms.link == link)
+			return t;
+		else {
+			if (!cand)
+				cand = t;
+		}
+	}
+
+	if (cand != NULL)
+		return cand;
+
+	if (itn->fb_tunnel_dev->flags & IFF_UP)
+		return netdev_priv(itn->fb_tunnel_dev);
+
+	return NULL;
+}
+EXPORT_SYMBOL(ip_tunnel_lookup);
+
+static struct ip_tunnel __rcu **__ip_bucket(struct ip_tunnel_net *itn,
+		struct ip_tunnel_parm *parms)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	__be32 key = parms->i_key;
+	unsigned int h = HASH(key);
+	int prio = 0;
+
+	if (local)
+		prio |= 1;
+	if (remote && !ipv4_is_multicast(remote)) {
+		prio |= 2;
+		h ^= HASH(remote);
+	}
+
+	return &itn->tunnels[prio][h];
+}
+
+static inline struct ip_tunnel __rcu **ip_bucket(struct ip_tunnel_net *itn,
+		struct ip_tunnel *t)
+{
+	return __ip_bucket(itn, &t->parms);
+}
+
+void ip_tunnel_link(struct ip_tunnel_net *itn, struct ip_tunnel *t)
+{
+	struct ip_tunnel __rcu **tp = ip_bucket(itn, t);
+
+	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
+	rcu_assign_pointer(*tp, t);
+}
+EXPORT_SYMBOL(ip_tunnel_link);
+
+void ip_tunnel_unlink(struct ip_tunnel_net *itn, struct ip_tunnel *t)
+{
+	struct ip_tunnel __rcu **tp;
+	struct ip_tunnel *iter;
+
+	for (tp = ip_bucket(itn, t);
+	     (iter = rtnl_dereference(*tp)) != NULL;
+	     tp = &iter->next) {
+		if (t == iter) {
+			rcu_assign_pointer(*tp, t->next);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(ip_tunnel_unlink);
+
+struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
+				 struct ip_tunnel_parm *parms,
+				 int type)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	__be32 key = parms->i_key;
+	int link = parms->link;
+	struct ip_tunnel *t;
+	struct ip_tunnel __rcu **tp;
+
+	for (tp = __ip_bucket(itn, parms);
+	     (t = rtnl_dereference(*tp)) != NULL;
+	     tp = &t->next)
+		if (local == t->parms.iph.saddr &&
+		    remote == t->parms.iph.daddr &&
+		    key == t->parms.i_key &&
+		    link == t->parms.link &&
+		    type == t->dev->type)
+			break;
+
+	return t;
+}
+EXPORT_SYMBOL(ip_tunnel_find);
+
+static void tunnel_setup(struct net_device *dev)
+{
+	/* do nothing. */
+}
+
+static struct net_device *__ip_tunnel_create(struct net *net,
+					  const struct rtnl_link_ops *ops,
+					  const struct net_device_ops *dev_ops,
+					  char *dev_name,
+					  struct ip_tunnel_parm *parms,
+					  int net_id)
+{
+	int err;
+	struct ip_tunnel *tunnel;
+	struct net_device *dev;
+	void (*setup)(struct net_device *dev);
+
+	if (ops && ops->setup)
+		setup = ops->setup;
+	else
+		setup = tunnel_setup;
+
+	ASSERT_RTNL();
+	dev = alloc_netdev(sizeof(struct ip_tunnel), dev_name, setup);
+	if (!dev) {
+		err = -ENOMEM;
+		goto failed;
+	}
+	dev_net_set(dev, net);
+
+	dev->rtnl_link_ops = ops;
+	dev->netdev_ops = dev_ops;
+
+	tunnel = netdev_priv(dev);
+	tunnel->parms = *parms;
+	tunnel->ipt_net_id = net_id;
+
+	err = register_netdevice(dev);
+	if (err)
+		goto failed_free;
+	dev_hold(dev);
+
+	return dev;
+
+failed_free:
+	free_netdev(dev);
+failed:
+	return ERR_PTR(err);
+}
+
+static struct ip_tunnel *ip_tunnel_create(struct net *net,
+					  struct ip_tunnel_net *itn,
+					  struct ip_tunnel_parm *parms)
+{
+	struct ip_tunnel *nt, *fbt;
+	struct net_device *dev;
+	char name[IFNAMSIZ];
+
+	if (parms->name[0])
+		strlcpy(name, parms->name, IFNAMSIZ);
+	else {
+		strlcpy(name, itn->ops->kind, IFNAMSIZ);
+		strncat(name, "%d", IFNAMSIZ);
+	}
+	fbt = netdev_priv(itn->fb_tunnel_dev);
+	dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops,
+				 itn->fb_tunnel_dev->netdev_ops,
+				 name, parms, fbt->ipt_net_id);
+	if (IS_ERR(dev))
+		return NULL;
+
+	dev->mtu = ip_tunnel_bind_dev(dev);
+
+	nt = netdev_priv(dev);
+	ip_tunnel_link(itn, nt);
+	return nt;
+}
+
+void ip_tunnel_err(struct ip_tunnel *t, struct sk_buff *skb, u32 info)
+{
+	const int code = icmp_hdr(skb)->code;
+	const int type = icmp_hdr(skb)->type;
+
+	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
+		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
+				 t->parms.link, 0, t->parms.iph.protocol, 0);
+		return;
+	}
+	if (type == ICMP_REDIRECT) {
+		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
+			      t->parms.iph.protocol, 0);
+		return;
+	}
+	if (t->parms.iph.daddr == 0 ||
+	    ipv4_is_multicast(t->parms.iph.daddr))
+		return;
+
+	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+		return;
+
+	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
+		t->err_count++;
+	else
+		t->err_count = 1;
+	t->err_time = jiffies;
+}
+EXPORT_SYMBOL(ip_tunnel_err);
+
+static inline u8
+ip_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
+{
+	u8 inner = 0;
+	if (skb->protocol == htons(ETH_P_IP))
+		inner = old_iph->tos;
+	else if (skb->protocol == htons(ETH_P_IPV6))
+		inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
+	return INET_ECN_encapsulate(tos, inner);
+}
+
+int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
+		  const struct tnl_ptk_info *tpi, bool log_ecn_error)
+{
+	int err;
+
+	struct pcpu_tstats *tstats;
+	const struct iphdr *iph = ip_hdr(skb);
+
+	secpath_reset(skb);
+
+	skb->protocol = tpi->proto;
+
+	skb->mac_header = skb->network_header;
+	skb->pkt_type = PACKET_HOST;
+
+	__pskb_pull(skb, tpi->hdr_len);
+	skb_postpull_rcsum(skb, skb_transport_header(skb), tpi->hdr_len);
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+	if (ipv4_is_multicast(iph->daddr)) {
+		/* Looped back packet, drop it! */
+		if (rt_is_output_route(skb_rtable(skb)))
+			goto drop;
+		tunnel->dev->stats.multicast++;
+		skb->pkt_type = PACKET_BROADCAST;
+	}
+#endif
+
+	if ((!(tpi->flags&TUNNEL_CSUM) && tunnel->parms.i_flags&TUNNEL_CSUM)) {
+		tunnel->dev->stats.rx_crc_errors++;
+		tunnel->dev->stats.rx_errors++;
+		goto drop;
+	}
+
+	if (tunnel->parms.i_flags&TUNNEL_SEQ) {
+		if (!(tpi->flags&TUNNEL_SEQ) ||
+		    (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
+			tunnel->dev->stats.rx_fifo_errors++;
+			tunnel->dev->stats.rx_errors++;
+			goto drop;
+		}
+		tunnel->i_seqno = ntohl(tpi->seq) + 1;
+	}
+
+	/* Warning: All skb pointers will be invalidated! */
+	if (tunnel->dev->type == ARPHRD_ETHER) {
+		if (!pskb_may_pull(skb, ETH_HLEN)) {
+			tunnel->dev->stats.rx_length_errors++;
+			tunnel->dev->stats.rx_errors++;
+			goto drop;
+		}
+
+		iph = ip_hdr(skb);
+		skb->protocol = eth_type_trans(skb, tunnel->dev);
+		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+	}
+
+	__skb_tunnel_rx(skb, tunnel->dev);
+
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	err = IP_ECN_decapsulate(iph, skb);
+	if (unlikely(err)) {
+		if (log_ecn_error)
+			net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
+					&iph->saddr, iph->tos);
+		if (err > 1) {
+			++tunnel->dev->stats.rx_frame_errors;
+			++tunnel->dev->stats.rx_errors;
+			goto drop;
+		}
+	}
+
+	tstats = this_cpu_ptr(tunnel->dev->tstats);
+	u64_stats_update_begin(&tstats->syncp);
+	tstats->rx_packets++;
+	tstats->rx_bytes += skb->len;
+	u64_stats_update_end(&tstats->syncp);
+
+	gro_cells_receive(&tunnel->gro_cells, skb);
+
+	return 0;
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_rcv);
+
+static void build_ip_header(struct iphdr  *iph, struct flowi4 *fl4, int proto,
+			    __be16 df, u8 tos, u8 ttl)
+{
+	/*
+	 *	Push down and install the IPIP header.
+	 */
+
+	iph->version		=	4;
+	iph->ihl		=	sizeof(struct iphdr) >> 2;
+	iph->frag_off		=	df;
+	iph->protocol		=	proto;
+	iph->tos		=	tos;
+	iph->daddr		=	fl4->daddr;
+	iph->saddr		=	fl4->saddr;
+	iph->ttl		=	ttl;
+}
+
+static inline struct rtable *ip_route_output_tunnel(struct net *net,
+						    struct flowi4 *fl4,
+						    int proto,
+						    __be32 daddr, __be32 saddr,
+						    __be32 key, __u8 tos, int oif)
+{
+	memset(fl4, 0, sizeof(*fl4));
+	fl4->flowi4_oif = oif;
+	fl4->daddr = daddr;
+	fl4->saddr = saddr;
+	fl4->flowi4_tos = tos;
+	fl4->flowi4_proto = proto;
+	fl4->fl4_gre_key = key;
+	return ip_route_output_key(net, fl4);
+}
+
+int  ip_tunnel_build_iphdr(struct sk_buff *skb, struct net_device *dev,
+			   const struct iphdr *tiph, int hlen,
+			   struct iphdr  *niph)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	const struct iphdr  *old_iph = ip_hdr(skb);
+	struct flowi4 fl4;
+	u8     tos, ttl;
+	__be16 df;
+	struct rtable *rt;			/* Route to the other host */
+	struct net_device *tdev;		/* Device to other host */
+	unsigned int max_headroom;		/* The extra header space needed */
+	__be32 dst;
+	int    mtu;
+	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+	if (dev->type == ARPHRD_ETHER)
+		IPCB(skb)->flags = 0;
+
+	dst = tiph->daddr;
+	if (dst == 0) {
+		/* NBMA tunnel */
+
+		if (skb_dst(skb) == NULL) {
+			dev->stats.tx_fifo_errors++;
+			goto tx_error;
+		}
+
+		if (skb->protocol == htons(ETH_P_IP)) {
+			rt = skb_rtable(skb);
+			dst = rt_nexthop(rt, old_iph->daddr);
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (skb->protocol == htons(ETH_P_IPV6)) {
+			const struct in6_addr *addr6;
+			struct neighbour *neigh;
+			bool do_tx_error_icmp;
+			int addr_type;
+
+			neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
+			if (neigh == NULL)
+				goto tx_error;
+
+			addr6 = (const struct in6_addr *)&neigh->primary_key;
+			addr_type = ipv6_addr_type(addr6);
+
+			if (addr_type == IPV6_ADDR_ANY) {
+				addr6 = &ipv6_hdr(skb)->daddr;
+				addr_type = ipv6_addr_type(addr6);
+			}
+
+			if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
+				do_tx_error_icmp = true;
+			else {
+				do_tx_error_icmp = false;
+				dst = addr6->s6_addr32[3];
+			}
+			neigh_release(neigh);
+			if (do_tx_error_icmp)
+				goto tx_error_icmp;
+		}
+#endif
+		else
+			goto tx_error;
+	}
+
+	tos = tiph->tos;
+	if (tos == 1) {
+		tos = 0;
+		if (skb->protocol == htons(ETH_P_IP))
+			tos = old_iph->tos;
+		else if (skb->protocol == htons(ETH_P_IPV6))
+			tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
+	}
+
+	rt = ip_route_output_tunnel(dev_net(dev), &fl4, tunnel->parms.iph.protocol,
+				 dst, tiph->saddr,
+				 tunnel->parms.o_key, RT_TOS(tos),
+				 tunnel->parms.link);
+	if (IS_ERR(rt)) {
+		dev->stats.tx_carrier_errors++;
+		goto tx_error;
+	}
+	tdev = rt->dst.dev;
+
+	if (tdev == dev) {
+		ip_rt_put(rt);
+		dev->stats.collisions++;
+		goto tx_error;
+	}
+
+	df = tiph->frag_off;
+	if (df)
+		mtu = dst_mtu(&rt->dst) - dev->hard_header_len - t_hlen;
+	else
+		mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
+
+	if (skb_dst(skb))
+		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		df |= (old_iph->frag_off&htons(IP_DF));
+
+		if ((old_iph->frag_off&htons(IP_DF)) &&
+		    mtu < ntohs(old_iph->tot_len)) {
+			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+			ip_rt_put(rt);
+			goto tx_error;
+		}
+	}
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (skb->protocol == htons(ETH_P_IPV6)) {
+		struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
+
+		if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
+			if ((tunnel->parms.iph.daddr &&
+			     !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
+			    rt6->rt6i_dst.plen == 128) {
+				rt6->rt6i_flags |= RTF_MODIFIED;
+				dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
+			}
+		}
+
+		if (mtu >= IPV6_MIN_MTU && mtu < skb->len - t_hlen + hlen) {
+			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+			ip_rt_put(rt);
+			goto tx_error;
+		}
+	}
+#endif
+
+	if (tunnel->err_count > 0) {
+		if (time_before(jiffies,
+				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
+			tunnel->err_count--;
+
+			dst_link_failure(skb);
+		} else
+			tunnel->err_count = 0;
+	}
+
+	tos = ip_ecn_encapsulate(tos, old_iph, skb);
+
+	ttl = tiph->ttl;
+	if (ttl == 0) {
+		if (skb->protocol == htons(ETH_P_IP))
+			ttl = old_iph->ttl;
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (skb->protocol == htons(ETH_P_IPV6))
+			ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
+#endif
+		else
+			ttl = ip4_dst_hoplimit(&rt->dst);
+	}
+
+	max_headroom = LL_RESERVED_SPACE(tdev) + hlen + rt->dst.header_len;
+	if (max_headroom > dev->needed_headroom)
+		dev->needed_headroom = max_headroom;
+
+	/*
+	 *	Push down and install the IPIP header.
+	 */
+
+	build_ip_header(niph, &fl4, tunnel->parms.iph.protocol, df, tos, ttl);
+	skb_dst_drop(skb);
+	skb_dst_set(skb, &rt->dst);
+	return 0;
+
+#if IS_ENABLED(CONFIG_IPV6)
+tx_error_icmp:
+	dst_link_failure(skb);
+#endif
+tx_error:
+	dev->stats.tx_errors++;
+	dev_kfree_skb(skb);
+	return -1;
+}
+EXPORT_SYMBOL(ip_tunnel_build_iphdr);
+
+static struct sk_buff *handle_offloads(struct sk_buff *skb)
+{
+	int err;
+
+	if (skb_is_gso(skb)) {
+		struct sk_buff *nskb;
+
+		nskb = skb_gso_segment(skb, 0);
+		if (IS_ERR(nskb)) {
+			err = PTR_ERR(nskb);
+			goto error_free;
+		}
+
+		consume_skb(skb);
+		skb = nskb;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		/* Pages aren't locked and could change at any time.
+		 * If this happens after we compute the checksum, the
+		 * checksum will be wrong.  We linearize now to avoid
+		 * this problem.
+		 */
+		err = __skb_linearize(skb);
+		if (unlikely(err))
+			goto error_free;
+
+		err = skb_checksum_help(skb);
+		if (unlikely(err))
+			goto error_free;
+	}
+
+	return skb;
+
+error_free:
+	kfree_skb(skb);
+	return ERR_PTR(err);
+}
+
+int ip_tunnel_xmit(struct sk_buff *skb, const struct iphdr *tiph,
+	const struct tnl_ptk_info *tpi,
+	void (*update_header)(struct sk_buff *skb, const struct tnl_ptk_info *tpi))
+{
+	struct rtable *rt = skb_rtable(skb);		/* Route to the other host */
+	struct iphdr *iph;
+	int err;
+	int pkt_len = 0;
+
+	nf_reset(skb);
+	skb = handle_offloads(skb);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+			IPSKB_REROUTED);
+
+	while (skb) {
+		struct sk_buff *next = skb->next;
+
+		skb->next = NULL;
+		skb_reset_transport_header(skb);
+		skb_push(skb, tpi->hdr_len + sizeof(struct iphdr));
+		skb_reset_network_header(skb);
+		skb_set_transport_header(skb, sizeof(struct iphdr));
+
+		iph = ip_hdr(skb);
+		memcpy(iph, tiph, sizeof(*tiph));
+
+		skb->ip_summed = CHECKSUM_NONE;
+		ip_select_ident(iph, &rt->dst, NULL);
+		(*update_header)(skb, tpi);
+
+		err = ip_local_out(skb);
+		if (unlikely(net_xmit_eval(err)))
+			goto next;
+
+		pkt_len += skb->len - skb_transport_offset(skb);
+next:
+		skb = next;
+	}
+	return pkt_len;
+}
+EXPORT_SYMBOL(ip_tunnel_xmit);
+
+int ip_tunnel_bind_dev(struct net_device *dev)
+{
+	struct net_device *tdev = NULL;
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	const struct iphdr *iph;
+	int hlen = LL_MAX_HEADER;
+	int mtu = ETH_DATA_LEN;
+	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+	iph = &tunnel->parms.iph;
+
+	/* Guess output device to choose reasonable mtu and needed_headroom */
+
+	if (iph->daddr) {
+		struct flowi4 fl4;
+		struct rtable *rt;
+
+		rt = ip_route_output_tunnel(dev_net(dev), &fl4,
+					 tunnel->parms.iph.protocol,
+					 iph->daddr, iph->saddr,
+					 tunnel->parms.o_key,
+					 RT_TOS(iph->tos),
+					 tunnel->parms.link);
+		if (!IS_ERR(rt)) {
+			tdev = rt->dst.dev;
+			ip_rt_put(rt);
+		}
+
+	}
+
+	if (!tdev && tunnel->parms.link)
+		tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+
+	if (tdev) {
+		hlen = tdev->hard_header_len + tdev->needed_headroom;
+		mtu = tdev->mtu;
+	}
+	dev->iflink = tunnel->parms.link;
+
+	dev->needed_headroom = t_hlen + hlen;
+	mtu -= (dev->hard_header_len + t_hlen);
+
+	if (mtu < 68)
+		mtu = 68;
+
+	return mtu;
+}
+EXPORT_SYMBOL(ip_tunnel_bind_dev);
+
+int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	int err = 0;
+	struct ip_tunnel_parm p;
+	struct ip_tunnel *t;
+	struct net *net = dev_net(dev);
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct ip_tunnel_net *itn = net_generic(net, tunnel->ipt_net_id);
+
+	switch (cmd) {
+	case SIOCGETTUNNEL:
+		t = NULL;
+		if (dev == itn->fb_tunnel_dev) {
+			err = itn->ops->get_ioctl_param(dev, ifr, &p);
+			if (err)
+				break;
+
+
+			t = ip_tunnel_find(itn, &p, itn->fb_tunnel_dev->type);
+		}
+		if (t == NULL)
+			t = netdev_priv(dev);
+		memcpy(&p, &t->parms, sizeof(p));
+		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+			err = -EFAULT;
+		break;
+
+	case SIOCADDTUNNEL:
+	case SIOCCHGTUNNEL:
+		err = itn->ops->get_ioctl_param(dev, ifr, &p);
+		if (err)
+			break;
+
+		t = ip_tunnel_find(itn, &p, itn->fb_tunnel_dev->type);
+
+		if (!t && (cmd == SIOCADDTUNNEL))
+			t = ip_tunnel_create(net, itn, &p);
+
+		if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+			if (t != NULL) {
+				if (t->dev != dev) {
+					err = -EEXIST;
+					break;
+				}
+			} else {
+				unsigned int nflags = 0;
+
+				if (ipv4_is_multicast(p.iph.daddr))
+					nflags = IFF_BROADCAST;
+				else if (p.iph.daddr)
+					nflags = IFF_POINTOPOINT;
+
+				if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
+					err = -EINVAL;
+					break;
+				}
+
+				t = netdev_priv(dev);
+				ip_tunnel_unlink(itn, t);
+				synchronize_net();
+
+				t->parms.iph.saddr = p.iph.saddr;
+				t->parms.iph.daddr = p.iph.daddr;
+				t->parms.i_key = p.i_key;
+				t->parms.o_key = p.o_key;
+				memcpy(dev->dev_addr, &p.iph.saddr, 4);
+				memcpy(dev->broadcast, &p.iph.daddr, 4);
+				ip_tunnel_link(itn, t);
+				netdev_state_change(dev);
+			}
+		}
+
+		if (t) {
+			err = 0;
+			if (cmd == SIOCCHGTUNNEL) {
+				t->parms.iph.ttl = p.iph.ttl;
+				t->parms.iph.tos = p.iph.tos;
+				t->parms.iph.frag_off = p.iph.frag_off;
+				if (t->parms.link != p.link) {
+					t->parms.link = p.link;
+					dev->mtu = ip_tunnel_bind_dev(dev);
+					netdev_state_change(dev);
+				}
+			}
+			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+				err = -EFAULT;
+		} else
+			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+		break;
+
+	case SIOCDELTUNNEL:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			goto done;
+
+		if (dev == itn->fb_tunnel_dev) {
+			err = itn->ops->get_ioctl_param(dev, ifr, &p);
+			if (err)
+				break;
+
+			err = -ENOENT;
+			t = ip_tunnel_find(itn, &p, itn->fb_tunnel_dev->type);
+			if (t == NULL)
+				goto done;
+			err = -EPERM;
+			if (t == netdev_priv(itn->fb_tunnel_dev))
+				goto done;
+			dev = t->dev;
+		}
+		unregister_netdevice(dev);
+		err = 0;
+		break;
+
+	default:
+		err = -EINVAL;
+	}
+
+done:
+	return err;
+}
+EXPORT_SYMBOL(ip_tunnel_ioctl);
+
+int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+	if (new_mtu < 68 ||
+	    new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_change_mtu);
+
+
+void ip_tunnel_dev_free(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+
+	gro_cells_destroy(&tunnel->gro_cells);
+
+	free_percpu(dev->tstats);
+	free_netdev(dev);
+}
+EXPORT_SYMBOL(ip_tunnel_dev_free);
+
+int __net_init ip_tunnel_init_fb(struct net *net, int ipt_net_id,
+				  struct rtnl_link_ops *ops,
+				  const struct net_device_ops *dev_ops,
+				  char *devname)
+{
+	struct ip_tunnel_net *itn = net_generic(net, ipt_net_id);
+	struct ip_tunnel_parm parms;
+
+	memset(&parms, 0, sizeof(parms));
+
+	rtnl_lock();
+	itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, dev_ops, devname,
+						&parms, ipt_net_id);
+	if (IS_ERR(itn->fb_tunnel_dev)) {
+		rtnl_unlock();
+		return PTR_ERR(itn->fb_tunnel_dev);
+	}
+
+	rcu_assign_pointer(itn->tunnels_wc[0],
+			   netdev_priv(itn->fb_tunnel_dev));
+	rtnl_unlock();
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_init_fb);
+
+static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head)
+{
+	int prio;
+
+	for (prio = 0; prio < 4; prio++) {
+		int h;
+		for (h = 0; h < HASH_SIZE; h++) {
+			struct ip_tunnel *t;
+
+			t = rtnl_dereference(itn->tunnels[prio][h]);
+
+			while (t != NULL) {
+				unregister_netdevice_queue(t->dev, head);
+				t = rtnl_dereference(t->next);
+			}
+		}
+	}
+}
+
+
+void __net_exit ip_tunnel_delete_fb(struct ip_tunnel_net *itn)
+{
+	LIST_HEAD(list);
+
+	rtnl_lock();
+	ip_tunnel_destroy(itn, &list);
+	unregister_netdevice_many(&list);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(ip_tunnel_delete_fb);
+
+/* Can be moved to ip-tunnel */
+int ip_tunnel_newlink(struct net *src_net, struct net_device *dev,
+			 struct nlattr *tb[],
+			struct nlattr *data[])
+{
+	struct ip_tunnel *nt;
+	struct net *net = dev_net(dev);
+	struct ip_tunnel_net *itn;
+	int mtu;
+	int err;
+
+	nt = netdev_priv(dev);
+	itn = net_generic(net, nt->ipt_net_id);
+	itn->ops->parse_netlink_parms(data, &nt->parms);
+
+	if (ip_tunnel_find(itn, &nt->parms, dev->type))
+		return -EEXIST;
+
+	dev->netdev_ops = itn->fb_tunnel_dev->netdev_ops;
+
+	err = register_netdevice(dev);
+	if (err)
+		goto out;
+
+	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+		eth_hw_addr_random(dev);
+
+	mtu = ip_tunnel_bind_dev(dev);
+	if (!tb[IFLA_MTU])
+		dev->mtu = mtu;
+
+	ip_tunnel_link(itn, nt);
+	dev_hold(dev);
+
+out:
+	return err;
+}
+EXPORT_SYMBOL(ip_tunnel_newlink);
+
+int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
+			    struct nlattr *data[])
+{
+	struct ip_tunnel *t, *nt;
+	struct net *net = dev_net(dev);
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct ip_tunnel_net *itn = net_generic(net, tunnel->ipt_net_id);
+
+	struct ip_tunnel_parm p;
+	int mtu;
+
+	if (dev == itn->fb_tunnel_dev)
+		return -EINVAL;
+
+	nt = netdev_priv(dev);
+	itn->ops->parse_netlink_parms(data, &p);
+
+	t = ip_tunnel_find(itn, &p, dev->type);
+
+	if (t) {
+		if (t->dev != dev)
+			return -EEXIST;
+	} else {
+		t = nt;
+
+		if (dev->type != ARPHRD_ETHER) {
+			unsigned int nflags = 0;
+
+			if (ipv4_is_multicast(p.iph.daddr))
+				nflags = IFF_BROADCAST;
+			else if (p.iph.daddr)
+				nflags = IFF_POINTOPOINT;
+
+			if ((dev->flags ^ nflags) &
+			    (IFF_POINTOPOINT | IFF_BROADCAST))
+				return -EINVAL;
+		}
+
+		ip_tunnel_unlink(itn, t);
+		t->parms.iph.saddr = p.iph.saddr;
+		t->parms.iph.daddr = p.iph.daddr;
+		t->parms.i_key = p.i_key;
+		if (dev->type != ARPHRD_ETHER) {
+			memcpy(dev->dev_addr, &p.iph.saddr, 4);
+			memcpy(dev->broadcast, &p.iph.daddr, 4);
+		}
+		ip_tunnel_link(itn, t);
+		netdev_state_change(dev);
+	}
+
+	t->parms.o_key = p.o_key;
+	t->parms.iph.ttl = p.iph.ttl;
+	t->parms.iph.tos = p.iph.tos;
+	t->parms.iph.frag_off = p.iph.frag_off;
+
+	if (t->parms.link != p.link) {
+		t->parms.link = p.link;
+		mtu = ip_tunnel_bind_dev(dev);
+		if (!tb[IFLA_MTU])
+			dev->mtu = mtu;
+		netdev_state_change(dev);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_changelink);
+
+/* Nice toy. Unfortunately, useless in real life :-)
+   It allows to construct virtual multiprotocol broadcast "LAN"
+   over the Internet, provided multicast routing is tuned.
+
+
+   I have no idea was this bicycle invented before me,
+   so that I had to set ARPHRD_IPGRE to a random value.
+   I have an impression, that Cisco could make something similar,
+   but this feature is apparently missing in IOS<=11.2(8).
+
+   I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
+   with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
+
+   ping -t 255 224.66.66.66
+
+   If nobody answers, mbone does not work.
+
+   ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
+   ip addr add 10.66.66.<somewhat>/24 dev Universe
+   ifconfig Universe up
+   ifconfig Universe add fe80::<Your_real_addr>/10
+   ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
+   ftp 10.66.66.66
+   ...
+   ftp fec0:6666:6666::193.233.7.65
+   ...
+
+ */
+
+static int ip_tunnel_header(struct sk_buff *skb, struct net_device *dev,
+			unsigned short type,
+			const void *daddr, const void *saddr, unsigned int len)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	int t_hlen = t->hlen + sizeof(struct iphdr);
+	struct iphdr *iph = (struct iphdr *)skb_push(skb, t_hlen);
+	__be16 *p = (__be16 *)(iph+1);
+
+	memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
+	p[0]		= t->parms.o_flags;
+	p[1]		= htons(type);
+
+	/*
+	 *	Set the source hardware address.
+	 */
+
+	if (saddr)
+		memcpy(&iph->saddr, saddr, 4);
+	if (daddr)
+		memcpy(&iph->daddr, daddr, 4);
+	if (iph->daddr)
+		return t_hlen;
+
+	return -t_hlen;
+}
+
+static int ip_tunnel_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+	const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
+	memcpy(haddr, &iph->saddr, 4);
+	return 4;
+}
+
+static const struct header_ops ip_tunnel_header_ops = {
+	.create	= ip_tunnel_header,
+	.parse	= ip_tunnel_header_parse,
+};
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+int ip_tunnel_open(struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+
+	if (ipv4_is_multicast(t->parms.iph.daddr)) {
+		struct flowi4 fl4;
+		struct rtable *rt;
+
+		rt = ip_route_output_gre(dev_net(dev), &fl4,
+					 t->parms.iph.daddr,
+					 t->parms.iph.saddr,
+					 t->parms.o_key,
+					 RT_TOS(t->parms.iph.tos),
+					 t->parms.link);
+		if (IS_ERR(rt))
+			return -EADDRNOTAVAIL;
+		dev = rt->dst.dev;
+		ip_rt_put(rt);
+		if (__in_dev_get_rtnl(dev) == NULL)
+			return -EADDRNOTAVAIL;
+		t->mlink = dev->ifindex;
+		ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_open);
+
+int ip_tunnel_close(struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+
+	if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
+		struct in_device *in_dev;
+		in_dev = inetdev_by_index(dev_net(dev), t->mlink);
+		if (in_dev)
+			ip_mc_dec_group(in_dev, t->parms.iph.daddr);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_close);
+#endif
+
+int ip_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct iphdr *iph;
+	int err;
+
+	dev->destructor		= ip_tunnel_dev_free;
+	dev->tstats = alloc_percpu(struct pcpu_tstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+
+	err = gro_cells_init(&tunnel->gro_cells, dev);
+	if (err) {
+		free_percpu(dev->tstats);
+		return err;
+	}
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	iph = &tunnel->parms.iph;
+	iph->version		= 4;
+	iph->ihl		= 5;
+
+	/* Can use a lockless transmit, unless we generate output sequences */
+	if (!(tunnel->parms.o_flags & TUNNEL_SEQ))
+		dev->features |= NETIF_F_LLTX;
+
+	if (iph->daddr) {
+		if (dev->type != ARPHRD_ETHER)
+			dev->flags |= IFF_POINTOPOINT;
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+		if (ipv4_is_multicast(iph->daddr)) {
+			if (!iph->saddr)
+				return -EINVAL;
+			dev->flags = IFF_BROADCAST;
+			dev->header_ops = &ip_tunnel_header_ops;
+		}
+#endif
+	} else
+		dev->header_ops = &ip_tunnel_header_ops;
+
+	return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_init);
+
+void ip_tunnel_uninit(struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct ip_tunnel_net *itn;
+
+	itn = net_generic(net, tunnel->ipt_net_id);
+	ip_tunnel_unlink(itn, netdev_priv(dev));
+	dev_put(dev);
+}
+EXPORT_SYMBOL(ip_tunnel_uninit);
+
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index e15b452..d3b0043 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -146,15 +146,6 @@ static void ipip_dev_free(struct net_device *dev);
 #define for_each_ip_tunnel_rcu(start) \
 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 
-/* often modified stats are per cpu, other are shared (netdev->stats) */
-struct pcpu_tstats {
-	u64	rx_packets;
-	u64	rx_bytes;
-	u64	tx_packets;
-	u64	tx_bytes;
-	struct u64_stats_sync	syncp;
-};
-
 static struct rtnl_link_stats64 *ipip_get_stats64(struct net_device *dev,
 						  struct rtnl_link_stats64 *tot)
 {
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 3ed54ff..91ba890 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -87,15 +87,6 @@ struct sit_net {
 #define for_each_ip_tunnel_rcu(start) \
 	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 
-/* often modified stats are per cpu, other are shared (netdev->stats) */
-struct pcpu_tstats {
-	u64	rx_packets;
-	u64	rx_bytes;
-	u64	tx_packets;
-	u64	tx_bytes;
-	struct u64_stats_sync	syncp;
-};
-
 static struct rtnl_link_stats64 *ipip6_get_stats64(struct net_device *dev,
 						   struct rtnl_link_stats64 *tot)
 {
-- 
1.7.1