Date:	Mon, 26 Aug 2013 11:37:38 -0500
From:	Dan Williams <dcbw@...hat.com>
To:	Steffen Klassert <steffen.klassert@...unet.com>
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH RFC 2/2] ipv6: Add support for IPsec virtual tunnel
 interfaces

On Mon, 2013-08-19 at 08:27 +0200, Steffen Klassert wrote:
> This patch adds IPv6  support for IPsec virtual tunnel interfaces
> (vti). IPsec virtual tunnel interfaces provide a routable interface
> for IPsec tunnel endpoints.

Are new ioctls for this kind of thing kosher?  Or should it be using
netlink instead?

Dan

> Signed-off-by: Steffen Klassert <steffen.klassert@...unet.com>
> ---
>  net/ipv6/Kconfig   |   11 +
>  net/ipv6/Makefile  |    1 +
>  net/ipv6/ip6_vti.c | 1092 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1104 insertions(+)
>  create mode 100644 net/ipv6/ip6_vti.c
> 
> diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
> index 11b13ea..e1a8d90 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 470a9c0..17bb830 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 0000000..fb0b6b0
> --- /dev/null
> +++ b/net/ipv6/ip6_vti.c
> @@ -0,0 +1,1092 @@
> +/*
> + *	IPv6 virtual tunneling interface
> + *
> + *	Copyright (C) 2013 secunet Security Networks AG
> + *
> + *	Author:
> + *	Steffen Klassert <steffen.klassert@...unet.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 <asm/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 IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
> +
> +#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 IPv6 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);
> +}
> +
> +/**
> + * vti6_tnl_err - tunnel error handler
> + *
> + * Description:
> + *   vti6_err() handle errors in the tunnel.
> + **/
> +static int
> +vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
> +	 u8 type, u8 code, int offset, __be32 info)
> +{
> +	struct net *net = dev_net(skb->dev);
> +	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
> +	struct ip6_tnl *t;
> +	int err = -ENOENT;
> +
> +	rcu_read_lock();
> +	if ((t = vti6_tnl_lookup(net, &ipv6h->daddr,
> +				 &ipv6h->saddr)) == NULL)
> +		goto out;
> +
> +	if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0)
> +		goto out;
> +
> +	err = 0;
> +
> +	switch (type) {
> +	case ICMPV6_DEST_UNREACH:
> +	case ICMPV6_TIME_EXCEED:
> +	case ICMPV6_PARAMPROB:
> +	break;
> +	case ICMPV6_PKT_TOOBIG:
> +		ip6_update_pmtu(skb, net, info, 0, 0);
> +	}
> +
> +
> +out:
> +	rcu_read_unlock();
> +	return err;
> +}
> +
> +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)
> +		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 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 = 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) {
> +		int strict = (ipv6_addr_type(&p->raddr) &
> +			      (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
> +
> +		struct rt6_info *rt = rt6_lookup(dev_net(dev),
> +						 &p->raddr, &p->laddr,
> +						 p->link, strict);
> +
> +		if (rt == NULL)
> +			return;
> +
> +		if (rt->dst.dev) {
> +			dev->hard_header_len = rt->dst.dev->hard_header_len +
> +				sizeof (struct ipv6hdr);
> +
> +			dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
> +
> +			if (dev->mtu < IPV6_MIN_MTU)
> +				dev->mtu = IPV6_MIN_MTU;
> +		}
> +		ip6_rt_put(rt);
> +	}
> +}
> +
> +/**
> + * 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;
> +
> +	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;
> +	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 IPv6 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 "ip6tnl0", 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_u32(data[IFLA_VTI_IKEY]);
> +
> +	if (data[IFLA_VTI_OKEY])
> +		parms->o_key = nla_get_u32(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_u32(skb, IFLA_VTI_IKEY, parm->i_key) ||
> +	    nla_put_u32(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 xfrm6_tunnel vti6_handler __read_mostly = {
> +	.handler	= vti6_rcv,
> +	.err_handler	= vti6_err,
> +	.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");


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