Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

Steffen Klassert says:

====================
1) Don't use a wildcard SA if a more precise one is in acquire state,
   from Fan Du.

2) Simplify the SA lookup when using wildcard source. We need to check
   only the destination in this case, from Fan Du.

3) Add a receive path hook for IPsec virtual tunnel interfaces
   to xfrm6_mode_tunnel.

4) Add support for IPsec virtual tunnel interfaces to ipv6.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 1137 insertions, 0 deletions

diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 11b13ea69db4..e1a8d903e366 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -153,6 +153,17 @@ config INET6_XFRM_MODE_ROUTEOPTIMIZATION
 	---help---
 	  Support for MIPv6 route optimization mode.
 
+config IPV6_VTI
+tristate "Virtual (secure) IPv6: tunneling"
+	select IPV6_TUNNEL
+	depends on INET6_XFRM_MODE_TUNNEL
+	---help---
+	Tunneling means encapsulating data of one protocol type within
+	another protocol and sending it over a channel that understands the
+	encapsulating protocol. This can be used with xfrm mode tunnel to give
+	the notion of a secure tunnel for IPSEC and then use routing protocol
+	on top.
+
 config IPV6_SIT
 	tristate "IPv6: IPv6-in-IPv4 tunnel (SIT driver)"
 	select INET_TUNNEL
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index 470a9c008e9b..17bb830872db 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_INET6_XFRM_MODE_BEET) += xfrm6_mode_beet.o
 obj-$(CONFIG_IPV6_MIP6) += mip6.o
 obj-$(CONFIG_NETFILTER)	+= netfilter/
 
+obj-$(CONFIG_IPV6_VTI) += ip6_vti.o
 obj-$(CONFIG_IPV6_SIT) += sit.o
 obj-$(CONFIG_IPV6_TUNNEL) += ip6_tunnel.o
 obj-$(CONFIG_IPV6_GRE) += ip6_gre.o
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
new file mode 100644
index 000000000000..ed94ba61dda0
--- /dev/null
+++ b/net/ipv6/ip6_vti.c
@@ -0,0 +1,1056 @@
+/*
+ *	IPv6 virtual tunneling interface
+ *
+ *	Copyright (C) 2013 secunet Security Networks AG
+ *
+ *	Author:
+ *	Steffen Klassert <steffen.klassert@secunet.com>
+ *
+ *	Based on:
+ *	net/ipv6/ip6_tunnel.c
+ *
+ *	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.
+ */
+
+#include <linux/module.h>
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/sockios.h>
+#include <linux/icmp.h>
+#include <linux/if.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/if_tunnel.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/icmpv6.h>
+#include <linux/init.h>
+#include <linux/route.h>
+#include <linux/rtnetlink.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/slab.h>
+#include <linux/hash.h>
+
+#include <linux/uaccess.h>
+#include <linux/atomic.h>
+
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/ip_tunnels.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/ip6_tunnel.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+#define HASH_SIZE_SHIFT  5
+#define HASH_SIZE (1 << HASH_SIZE_SHIFT)
+
+static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
+{
+	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
+
+	return hash_32(hash, HASH_SIZE_SHIFT);
+}
+
+static int vti6_dev_init(struct net_device *dev);
+static void vti6_dev_setup(struct net_device *dev);
+static struct rtnl_link_ops vti6_link_ops __read_mostly;
+
+static int vti6_net_id __read_mostly;
+struct vti6_net {
+	/* the vti6 tunnel fallback device */
+	struct net_device *fb_tnl_dev;
+	/* lists for storing tunnels in use */
+	struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
+	struct ip6_tnl __rcu *tnls_wc[1];
+	struct ip6_tnl __rcu **tnls[2];
+};
+
+static struct net_device_stats *vti6_get_stats(struct net_device *dev)
+{
+	struct pcpu_tstats sum = { 0 };
+	int i;
+
+	for_each_possible_cpu(i) {
+		const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
+
+		sum.rx_packets += tstats->rx_packets;
+		sum.rx_bytes   += tstats->rx_bytes;
+		sum.tx_packets += tstats->tx_packets;
+		sum.tx_bytes   += tstats->tx_bytes;
+	}
+	dev->stats.rx_packets = sum.rx_packets;
+	dev->stats.rx_bytes   = sum.rx_bytes;
+	dev->stats.tx_packets = sum.tx_packets;
+	dev->stats.tx_bytes   = sum.tx_bytes;
+	return &dev->stats;
+}
+
+#define for_each_vti6_tunnel_rcu(start) \
+	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
+
+/**
+ * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
+ *   @net: network namespace
+ *   @remote: the address of the tunnel exit-point
+ *   @local: the address of the tunnel entry-point
+ *
+ * Return:
+ *   tunnel matching given end-points if found,
+ *   else fallback tunnel if its device is up,
+ *   else %NULL
+ **/
+static struct ip6_tnl *
+vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
+		const struct in6_addr *local)
+{
+	unsigned int hash = HASH(remote, local);
+	struct ip6_tnl *t;
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
+		if (ipv6_addr_equal(local, &t->parms.laddr) &&
+		    ipv6_addr_equal(remote, &t->parms.raddr) &&
+		    (t->dev->flags & IFF_UP))
+			return t;
+	}
+	t = rcu_dereference(ip6n->tnls_wc[0]);
+	if (t && (t->dev->flags & IFF_UP))
+		return t;
+
+	return NULL;
+}
+
+/**
+ * vti6_tnl_bucket - get head of list matching given tunnel parameters
+ *   @p: parameters containing tunnel end-points
+ *
+ * Description:
+ *   vti6_tnl_bucket() returns the head of the list matching the
+ *   &struct in6_addr entries laddr and raddr in @p.
+ *
+ * Return: head of IPv6 tunnel list
+ **/
+static struct ip6_tnl __rcu **
+vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
+{
+	const struct in6_addr *remote = &p->raddr;
+	const struct in6_addr *local = &p->laddr;
+	unsigned int h = 0;
+	int prio = 0;
+
+	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
+		prio = 1;
+		h = HASH(remote, local);
+	}
+	return &ip6n->tnls[prio][h];
+}
+
+static void
+vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
+{
+	struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);
+
+	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
+	rcu_assign_pointer(*tp, t);
+}
+
+static void
+vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
+{
+	struct ip6_tnl __rcu **tp;
+	struct ip6_tnl *iter;
+
+	for (tp = vti6_tnl_bucket(ip6n, &t->parms);
+	     (iter = rtnl_dereference(*tp)) != NULL;
+	     tp = &iter->next) {
+		if (t == iter) {
+			rcu_assign_pointer(*tp, t->next);
+			break;
+		}
+	}
+}
+
+static void vti6_dev_free(struct net_device *dev)
+{
+	free_percpu(dev->tstats);
+	free_netdev(dev);
+}
+
+static int vti6_tnl_create2(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	int err;
+
+	err = vti6_dev_init(dev);
+	if (err < 0)
+		goto out;
+
+	err = register_netdevice(dev);
+	if (err < 0)
+		goto out;
+
+	strcpy(t->parms.name, dev->name);
+	dev->rtnl_link_ops = &vti6_link_ops;
+
+	dev_hold(dev);
+	vti6_tnl_link(ip6n, t);
+
+	return 0;
+
+out:
+	return err;
+}
+
+static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
+{
+	struct net_device *dev;
+	struct ip6_tnl *t;
+	char name[IFNAMSIZ];
+	int err;
+
+	if (p->name[0])
+		strlcpy(name, p->name, IFNAMSIZ);
+	else
+		sprintf(name, "ip6_vti%%d");
+
+	dev = alloc_netdev(sizeof(*t), name, vti6_dev_setup);
+	if (dev == NULL)
+		goto failed;
+
+	dev_net_set(dev, net);
+
+	t = netdev_priv(dev);
+	t->parms = *p;
+	t->net = dev_net(dev);
+
+	err = vti6_tnl_create2(dev);
+	if (err < 0)
+		goto failed_free;
+
+	return t;
+
+failed_free:
+	vti6_dev_free(dev);
+failed:
+	return NULL;
+}
+
+/**
+ * vti6_locate - find or create tunnel matching given parameters
+ *   @net: network namespace
+ *   @p: tunnel parameters
+ *   @create: != 0 if allowed to create new tunnel if no match found
+ *
+ * Description:
+ *   vti6_locate() first tries to locate an existing tunnel
+ *   based on @parms. If this is unsuccessful, but @create is set a new
+ *   tunnel device is created and registered for use.
+ *
+ * Return:
+ *   matching tunnel or NULL
+ **/
+static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
+				   int create)
+{
+	const struct in6_addr *remote = &p->raddr;
+	const struct in6_addr *local = &p->laddr;
+	struct ip6_tnl __rcu **tp;
+	struct ip6_tnl *t;
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	for (tp = vti6_tnl_bucket(ip6n, p);
+	     (t = rtnl_dereference(*tp)) != NULL;
+	     tp = &t->next) {
+		if (ipv6_addr_equal(local, &t->parms.laddr) &&
+		    ipv6_addr_equal(remote, &t->parms.raddr))
+			return t;
+	}
+	if (!create)
+		return NULL;
+	return vti6_tnl_create(net, p);
+}
+
+/**
+ * vti6_dev_uninit - tunnel device uninitializer
+ *   @dev: the device to be destroyed
+ *
+ * Description:
+ *   vti6_dev_uninit() removes tunnel from its list
+ **/
+static void vti6_dev_uninit(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	if (dev == ip6n->fb_tnl_dev)
+		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
+	else
+		vti6_tnl_unlink(ip6n, t);
+	ip6_tnl_dst_reset(t);
+	dev_put(dev);
+}
+
+static int vti6_rcv(struct sk_buff *skb)
+{
+	struct ip6_tnl *t;
+	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+
+	rcu_read_lock();
+
+	if ((t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
+				 &ipv6h->daddr)) != NULL) {
+		struct pcpu_tstats *tstats;
+
+		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
+			rcu_read_unlock();
+			goto discard;
+		}
+
+		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+			rcu_read_unlock();
+			return 0;
+		}
+
+		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
+			t->dev->stats.rx_dropped++;
+			rcu_read_unlock();
+			goto discard;
+		}
+
+		tstats = this_cpu_ptr(t->dev->tstats);
+		tstats->rx_packets++;
+		tstats->rx_bytes += skb->len;
+
+		skb->mark = 0;
+		secpath_reset(skb);
+		skb->dev = t->dev;
+
+		rcu_read_unlock();
+		return 0;
+	}
+	rcu_read_unlock();
+	return 1;
+
+discard:
+	kfree_skb(skb);
+	return 0;
+}
+
+/**
+ * vti6_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
+vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
+{
+	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
+}
+
+/**
+ * vti6_xmit - send a packet
+ *   @skb: the outgoing socket buffer
+ *   @dev: the outgoing tunnel device
+ **/
+static int vti6_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net_device_stats *stats = &t->dev->stats;
+	struct dst_entry *dst = NULL, *ndst = NULL;
+	struct flowi6 fl6;
+	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+	struct net_device *tdev;
+	int err = -1;
+
+	if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
+	    !ip6_tnl_xmit_ctl(t) || vti6_addr_conflict(t, ipv6h))
+		return err;
+
+	dst = ip6_tnl_dst_check(t);
+	if (!dst) {
+		memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
+
+		ndst = ip6_route_output(net, NULL, &fl6);
+
+		if (ndst->error)
+			goto tx_err_link_failure;
+		ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(&fl6), NULL, 0);
+		if (IS_ERR(ndst)) {
+			err = PTR_ERR(ndst);
+			ndst = NULL;
+			goto tx_err_link_failure;
+		}
+		dst = ndst;
+	}
+
+	if (!dst->xfrm || dst->xfrm->props.mode != XFRM_MODE_TUNNEL)
+		goto tx_err_link_failure;
+
+	tdev = dst->dev;
+
+	if (tdev == dev) {
+		stats->collisions++;
+		net_warn_ratelimited("%s: Local routing loop detected!\n",
+				     t->parms.name);
+		goto tx_err_dst_release;
+	}
+
+
+	skb_dst_drop(skb);
+	skb_dst_set_noref(skb, dst);
+
+	ip6tunnel_xmit(skb, dev);
+	if (ndst) {
+		dev->mtu = dst_mtu(ndst);
+		ip6_tnl_dst_store(t, ndst);
+	}
+
+	return 0;
+tx_err_link_failure:
+	stats->tx_carrier_errors++;
+	dst_link_failure(skb);
+tx_err_dst_release:
+	dst_release(ndst);
+	return err;
+}
+
+static netdev_tx_t
+vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net_device_stats *stats = &t->dev->stats;
+	int ret;
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IPV6):
+		ret = vti6_xmit(skb, dev);
+		break;
+	default:
+		goto tx_err;
+	}
+
+	if (ret < 0)
+		goto tx_err;
+
+	return NETDEV_TX_OK;
+
+tx_err:
+	stats->tx_errors++;
+	stats->tx_dropped++;
+	kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static void vti6_link_config(struct ip6_tnl *t)
+{
+	struct dst_entry *dst;
+	struct net_device *dev = t->dev;
+	struct __ip6_tnl_parm *p = &t->parms;
+	struct flowi6 *fl6 = &t->fl.u.ip6;
+
+	memcpy(dev->dev_addr, &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->flowi6_mark = be32_to_cpu(p->i_key);
+	fl6->flowi6_proto = p->proto;
+	fl6->flowlabel = 0;
+
+	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->flags |= IFF_POINTOPOINT;
+	else
+		dev->flags &= ~IFF_POINTOPOINT;
+
+	dev->iflink = p->link;
+
+	if (p->flags & IP6_TNL_F_CAP_XMIT) {
+
+		dst = ip6_route_output(dev_net(dev), NULL, fl6);
+		if (dst->error)
+			return;
+
+		dst = xfrm_lookup(dev_net(dev), dst, flowi6_to_flowi(fl6),
+				  NULL, 0);
+		if (IS_ERR(dst))
+			return;
+
+		if (dst->dev) {
+			dev->hard_header_len = dst->dev->hard_header_len;
+
+			dev->mtu = dst_mtu(dst);
+
+			if (dev->mtu < IPV6_MIN_MTU)
+				dev->mtu = IPV6_MIN_MTU;
+		}
+		dst_release(dst);
+	}
+}
+
+/**
+ * vti6_tnl_change - update the tunnel parameters
+ *   @t: tunnel to be changed
+ *   @p: tunnel configuration parameters
+ *
+ * Description:
+ *   vti6_tnl_change() updates the tunnel parameters
+ **/
+static int
+vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
+{
+	t->parms.laddr = p->laddr;
+	t->parms.raddr = p->raddr;
+	t->parms.link = p->link;
+	t->parms.i_key = p->i_key;
+	t->parms.o_key = p->o_key;
+	t->parms.proto = p->proto;
+	ip6_tnl_dst_reset(t);
+	vti6_link_config(t);
+	return 0;
+}
+
+static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
+{
+	struct net *net = dev_net(t->dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	int err;
+
+	vti6_tnl_unlink(ip6n, t);
+	synchronize_net();
+	err = vti6_tnl_change(t, p);
+	vti6_tnl_link(ip6n, t);
+	netdev_state_change(t->dev);
+	return err;
+}
+
+static void
+vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
+{
+	p->laddr = u->laddr;
+	p->raddr = u->raddr;
+	p->link = u->link;
+	p->i_key = u->i_key;
+	p->o_key = u->o_key;
+	p->proto = u->proto;
+
+	memcpy(p->name, u->name, sizeof(u->name));
+}
+
+static void
+vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
+{
+	u->laddr = p->laddr;
+	u->raddr = p->raddr;
+	u->link = p->link;
+	u->i_key = p->i_key;
+	u->o_key = p->o_key;
+	u->proto = p->proto;
+
+	memcpy(u->name, p->name, sizeof(u->name));
+}
+
+/**
+ * vti6_tnl_ioctl - configure vti6 tunnels from userspace
+ *   @dev: virtual device associated with tunnel
+ *   @ifr: parameters passed from userspace
+ *   @cmd: command to be performed
+ *
+ * Description:
+ *   vti6_ioctl() is used for managing vti6 tunnels
+ *   from userspace.
+ *
+ *   The possible commands are the following:
+ *     %SIOCGETTUNNEL: get tunnel parameters for device
+ *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
+ *     %SIOCCHGTUNNEL: change tunnel parameters to those given
+ *     %SIOCDELTUNNEL: delete tunnel
+ *
+ *   The fallback device "ip6_vti0", created during module
+ *   initialization, can be used for creating other tunnel devices.
+ *
+ * Return:
+ *   0 on success,
+ *   %-EFAULT if unable to copy data to or from userspace,
+ *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
+ *   %-EINVAL if passed tunnel parameters are invalid,
+ *   %-EEXIST if changing a tunnel's parameters would cause a conflict
+ *   %-ENODEV if attempting to change or delete a nonexisting device
+ **/
+static int
+vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	int err = 0;
+	struct ip6_tnl_parm2 p;
+	struct __ip6_tnl_parm p1;
+	struct ip6_tnl *t = NULL;
+	struct net *net = dev_net(dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	switch (cmd) {
+	case SIOCGETTUNNEL:
+		if (dev == ip6n->fb_tnl_dev) {
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+				err = -EFAULT;
+				break;
+			}
+			vti6_parm_from_user(&p1, &p);
+			t = vti6_locate(net, &p1, 0);
+		} else {
+			memset(&p, 0, sizeof(p));
+		}
+		if (t == NULL)
+			t = netdev_priv(dev);
+		vti6_parm_to_user(&p, &t->parms);
+		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+			err = -EFAULT;
+		break;
+	case SIOCADDTUNNEL:
+	case SIOCCHGTUNNEL:
+		err = -EPERM;
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+			break;
+		err = -EFAULT;
+		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+			break;
+		err = -EINVAL;
+		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
+			break;
+		vti6_parm_from_user(&p1, &p);
+		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
+		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
+			if (t != NULL) {
+				if (t->dev != dev) {
+					err = -EEXIST;
+					break;
+				}
+			} else
+				t = netdev_priv(dev);
+
+			err = vti6_update(t, &p1);
+		}
+		if (t) {
+			err = 0;
+			vti6_parm_to_user(&p, &t->parms);
+			if (copy_to_user(ifr->ifr_ifru.ifru_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))
+			break;
+
+		if (dev == ip6n->fb_tnl_dev) {
+			err = -EFAULT;
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+				break;
+			err = -ENOENT;
+			vti6_parm_from_user(&p1, &p);
+			t = vti6_locate(net, &p1, 0);
+			if (t == NULL)
+				break;
+			err = -EPERM;
+			if (t->dev == ip6n->fb_tnl_dev)
+				break;
+			dev = t->dev;
+		}
+		err = 0;
+		unregister_netdevice(dev);
+		break;
+	default:
+		err = -EINVAL;
+	}
+	return err;
+}
+
+/**
+ * vti6_tnl_change_mtu - change mtu manually for tunnel device
+ *   @dev: virtual device associated with tunnel
+ *   @new_mtu: the new mtu
+ *
+ * Return:
+ *   0 on success,
+ *   %-EINVAL if mtu too small
+ **/
+static int vti6_change_mtu(struct net_device *dev, int new_mtu)
+{
+	if (new_mtu < IPV6_MIN_MTU)
+		return -EINVAL;
+
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+static const struct net_device_ops vti6_netdev_ops = {
+	.ndo_uninit	= vti6_dev_uninit,
+	.ndo_start_xmit = vti6_tnl_xmit,
+	.ndo_do_ioctl	= vti6_ioctl,
+	.ndo_change_mtu = vti6_change_mtu,
+	.ndo_get_stats	= vti6_get_stats,
+};
+
+/**
+ * vti6_dev_setup - setup virtual tunnel device
+ *   @dev: virtual device associated with tunnel
+ *
+ * Description:
+ *   Initialize function pointers and device parameters
+ **/
+static void vti6_dev_setup(struct net_device *dev)
+{
+	struct ip6_tnl *t;
+
+	dev->netdev_ops = &vti6_netdev_ops;
+	dev->destructor = vti6_dev_free;
+
+	dev->type = ARPHRD_TUNNEL6;
+	dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
+	dev->mtu = ETH_DATA_LEN;
+	t = netdev_priv(dev);
+	dev->flags |= IFF_NOARP;
+	dev->addr_len = sizeof(struct in6_addr);
+	dev->features |= NETIF_F_NETNS_LOCAL;
+	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+}
+
+/**
+ * vti6_dev_init_gen - general initializer for all tunnel devices
+ *   @dev: virtual device associated with tunnel
+ **/
+static inline int vti6_dev_init_gen(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+
+	t->dev = dev;
+	t->net = dev_net(dev);
+	dev->tstats = alloc_percpu(struct pcpu_tstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+	return 0;
+}
+
+/**
+ * vti6_dev_init - initializer for all non fallback tunnel devices
+ *   @dev: virtual device associated with tunnel
+ **/
+static int vti6_dev_init(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	int err = vti6_dev_init_gen(dev);
+
+	if (err)
+		return err;
+	vti6_link_config(t);
+	return 0;
+}
+
+/**
+ * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
+ *   @dev: fallback device
+ *
+ * Return: 0
+ **/
+static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
+{
+	struct ip6_tnl *t = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	int err = vti6_dev_init_gen(dev);
+
+	if (err)
+		return err;
+
+	t->parms.proto = IPPROTO_IPV6;
+	dev_hold(dev);
+
+	vti6_link_config(t);
+
+	rcu_assign_pointer(ip6n->tnls_wc[0], t);
+	return 0;
+}
+
+static int vti6_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	return 0;
+}
+
+static void vti6_netlink_parms(struct nlattr *data[],
+			       struct __ip6_tnl_parm *parms)
+{
+	memset(parms, 0, sizeof(*parms));
+
+	if (!data)
+		return;
+
+	if (data[IFLA_VTI_LINK])
+		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
+
+	if (data[IFLA_VTI_LOCAL])
+		nla_memcpy(&parms->laddr, data[IFLA_VTI_LOCAL],
+			   sizeof(struct in6_addr));
+
+	if (data[IFLA_VTI_REMOTE])
+		nla_memcpy(&parms->raddr, data[IFLA_VTI_REMOTE],
+			   sizeof(struct in6_addr));
+
+	if (data[IFLA_VTI_IKEY])
+		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
+
+	if (data[IFLA_VTI_OKEY])
+		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
+}
+
+static int vti6_newlink(struct net *src_net, struct net_device *dev,
+			struct nlattr *tb[], struct nlattr *data[])
+{
+	struct net *net = dev_net(dev);
+	struct ip6_tnl *nt;
+
+	nt = netdev_priv(dev);
+	vti6_netlink_parms(data, &nt->parms);
+
+	nt->parms.proto = IPPROTO_IPV6;
+
+	if (vti6_locate(net, &nt->parms, 0))
+		return -EEXIST;
+
+	return vti6_tnl_create2(dev);
+}
+
+static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
+			   struct nlattr *data[])
+{
+	struct ip6_tnl *t;
+	struct __ip6_tnl_parm p;
+	struct net *net = dev_net(dev);
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	if (dev == ip6n->fb_tnl_dev)
+		return -EINVAL;
+
+	vti6_netlink_parms(data, &p);
+
+	t = vti6_locate(net, &p, 0);
+
+	if (t) {
+		if (t->dev != dev)
+			return -EEXIST;
+	} else
+		t = netdev_priv(dev);
+
+	return vti6_update(t, &p);
+}
+
+static size_t vti6_get_size(const struct net_device *dev)
+{
+	return
+		/* IFLA_VTI_LINK */
+		nla_total_size(4) +
+		/* IFLA_VTI_LOCAL */
+		nla_total_size(sizeof(struct in6_addr)) +
+		/* IFLA_VTI_REMOTE */
+		nla_total_size(sizeof(struct in6_addr)) +
+		/* IFLA_VTI_IKEY */
+		nla_total_size(4) +
+		/* IFLA_VTI_OKEY */
+		nla_total_size(4) +
+		0;
+}
+
+static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct ip6_tnl *tunnel = netdev_priv(dev);
+	struct __ip6_tnl_parm *parm = &tunnel->parms;
+
+	if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
+	    nla_put(skb, IFLA_VTI_LOCAL, sizeof(struct in6_addr),
+		    &parm->laddr) ||
+	    nla_put(skb, IFLA_VTI_REMOTE, sizeof(struct in6_addr),
+		    &parm->raddr) ||
+	    nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
+	    nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
+	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
+	[IFLA_VTI_LOCAL]	= { .len = sizeof(struct in6_addr) },
+	[IFLA_VTI_REMOTE]	= { .len = sizeof(struct in6_addr) },
+	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
+	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
+};
+
+static struct rtnl_link_ops vti6_link_ops __read_mostly = {
+	.kind		= "vti6",
+	.maxtype	= IFLA_VTI_MAX,
+	.policy		= vti6_policy,
+	.priv_size	= sizeof(struct ip6_tnl),
+	.setup		= vti6_dev_setup,
+	.validate	= vti6_validate,
+	.newlink	= vti6_newlink,
+	.changelink	= vti6_changelink,
+	.get_size	= vti6_get_size,
+	.fill_info	= vti6_fill_info,
+};
+
+static struct xfrm_tunnel_notifier vti6_handler __read_mostly = {
+	.handler	= vti6_rcv,
+	.priority	=	1,
+};
+
+static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n)
+{
+	int h;
+	struct ip6_tnl *t;
+	LIST_HEAD(list);
+
+	for (h = 0; h < HASH_SIZE; h++) {
+		t = rtnl_dereference(ip6n->tnls_r_l[h]);
+		while (t != NULL) {
+			unregister_netdevice_queue(t->dev, &list);
+			t = rtnl_dereference(t->next);
+		}
+	}
+
+	t = rtnl_dereference(ip6n->tnls_wc[0]);
+	unregister_netdevice_queue(t->dev, &list);
+	unregister_netdevice_many(&list);
+}
+
+static int __net_init vti6_init_net(struct net *net)
+{
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+	struct ip6_tnl *t = NULL;
+	int err;
+
+	ip6n->tnls[0] = ip6n->tnls_wc;
+	ip6n->tnls[1] = ip6n->tnls_r_l;
+
+	err = -ENOMEM;
+	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
+					vti6_dev_setup);
+
+	if (!ip6n->fb_tnl_dev)
+		goto err_alloc_dev;
+	dev_net_set(ip6n->fb_tnl_dev, net);
+
+	err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
+	if (err < 0)
+		goto err_register;
+
+	err = register_netdev(ip6n->fb_tnl_dev);
+	if (err < 0)
+		goto err_register;
+
+	t = netdev_priv(ip6n->fb_tnl_dev);
+
+	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
+	return 0;
+
+err_register:
+	vti6_dev_free(ip6n->fb_tnl_dev);
+err_alloc_dev:
+	return err;
+}
+
+static void __net_exit vti6_exit_net(struct net *net)
+{
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
+
+	rtnl_lock();
+	vti6_destroy_tunnels(ip6n);
+	rtnl_unlock();
+}
+
+static struct pernet_operations vti6_net_ops = {
+	.init = vti6_init_net,
+	.exit = vti6_exit_net,
+	.id   = &vti6_net_id,
+	.size = sizeof(struct vti6_net),
+};
+
+/**
+ * vti6_tunnel_init - register protocol and reserve needed resources
+ *
+ * Return: 0 on success
+ **/
+static int __init vti6_tunnel_init(void)
+{
+	int  err;
+
+	err = register_pernet_device(&vti6_net_ops);
+	if (err < 0)
+		goto out_pernet;
+
+	err = xfrm6_mode_tunnel_input_register(&vti6_handler);
+	if (err < 0) {
+		pr_err("%s: can't register vti6\n", __func__);
+		goto out;
+	}
+	err = rtnl_link_register(&vti6_link_ops);
+	if (err < 0)
+		goto rtnl_link_failed;
+
+	return 0;
+
+rtnl_link_failed:
+	xfrm6_mode_tunnel_input_deregister(&vti6_handler);
+out:
+	unregister_pernet_device(&vti6_net_ops);
+out_pernet:
+	return err;
+}
+
+/**
+ * vti6_tunnel_cleanup - free resources and unregister protocol
+ **/
+static void __exit vti6_tunnel_cleanup(void)
+{
+	rtnl_link_unregister(&vti6_link_ops);
+	if (xfrm6_mode_tunnel_input_deregister(&vti6_handler))
+		pr_info("%s: can't deregister vti6\n", __func__);
+
+	unregister_pernet_device(&vti6_net_ops);
+}
+
+module_init(vti6_tunnel_init);
+module_exit(vti6_tunnel_cleanup);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("vti6");
+MODULE_ALIAS_NETDEV("ip6_vti0");
+MODULE_AUTHOR("Steffen Klassert");
+MODULE_DESCRIPTION("IPv6 virtual tunnel interface");
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 4770d515c2c8..cb04f7a16b5e 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -18,6 +18,65 @@
 #include <net/ipv6.h>
 #include <net/xfrm.h>
 
+/* Informational hook. The decap is still done here. */
+static struct xfrm_tunnel_notifier __rcu *rcv_notify_handlers __read_mostly;
+static DEFINE_MUTEX(xfrm6_mode_tunnel_input_mutex);
+
+int xfrm6_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler)
+{
+	struct xfrm_tunnel_notifier __rcu **pprev;
+	struct xfrm_tunnel_notifier *t;
+	int ret = -EEXIST;
+	int priority = handler->priority;
+
+	mutex_lock(&xfrm6_mode_tunnel_input_mutex);
+
+	for (pprev = &rcv_notify_handlers;
+	     (t = rcu_dereference_protected(*pprev,
+	     lockdep_is_held(&xfrm6_mode_tunnel_input_mutex))) != NULL;
+	     pprev = &t->next) {
+		if (t->priority > priority)
+			break;
+		if (t->priority == priority)
+			goto err;
+
+	}
+
+	handler->next = *pprev;
+	rcu_assign_pointer(*pprev, handler);
+
+	ret = 0;
+
+err:
+	mutex_unlock(&xfrm6_mode_tunnel_input_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm6_mode_tunnel_input_register);
+
+int xfrm6_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler)
+{
+	struct xfrm_tunnel_notifier __rcu **pprev;
+	struct xfrm_tunnel_notifier *t;
+	int ret = -ENOENT;
+
+	mutex_lock(&xfrm6_mode_tunnel_input_mutex);
+	for (pprev = &rcv_notify_handlers;
+	     (t = rcu_dereference_protected(*pprev,
+	     lockdep_is_held(&xfrm6_mode_tunnel_input_mutex))) != NULL;
+	     pprev = &t->next) {
+		if (t == handler) {
+			*pprev = handler->next;
+			ret = 0;
+			break;
+		}
+	}
+	mutex_unlock(&xfrm6_mode_tunnel_input_mutex);
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm6_mode_tunnel_input_deregister);
+
 static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
 {
 	const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
@@ -63,8 +122,15 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 	return 0;
 }
 
+#define for_each_input_rcu(head, handler)	\
+	for (handler = rcu_dereference(head);	\
+	     handler != NULL;			\
+	     handler = rcu_dereference(handler->next))
+
+
 static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 {
+	struct xfrm_tunnel_notifier *handler;
 	int err = -EINVAL;
 
 	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
@@ -72,6 +138,9 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 		goto out;
 
+	for_each_input_rcu(rcv_notify_handlers, handler)
+		handler->handler(skb);
+
 	err = skb_unclone(skb, GFP_ATOMIC);
 	if (err)
 		goto out;