ip6_vti.c 27.3 KB
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/*
 *	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/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];
};

#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);
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	struct in6_addr any;
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	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;
	}
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	memset(&any, 0, sizeof(any));
	hash = HASH(&any, local);
	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

	hash = HASH(remote, &any);
	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

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	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 = 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");

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	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
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	if (!dev)
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		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) &&
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		    ipv6_addr_equal(remote, &t->parms.raddr)) {
			if (create)
				return NULL;

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			return t;
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		}
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	}
	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);
	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();
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	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
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	if (t) {
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		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;
		}

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		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
		skb->mark = be32_to_cpu(t->parms.i_key);
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		rcu_read_unlock();
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		return xfrm6_rcv(skb);
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	}
	rcu_read_unlock();
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	return -EINVAL;
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discard:
	kfree_skb(skb);
	return 0;
}

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static int vti6_rcv_cb(struct sk_buff *skb, int err)
{
	unsigned short family;
	struct net_device *dev;
	struct pcpu_sw_netstats *tstats;
	struct xfrm_state *x;
	struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;

	if (!t)
		return 1;

	dev = t->dev;

	if (err) {
		dev->stats.rx_errors++;
		dev->stats.rx_dropped++;

		return 0;
	}

	x = xfrm_input_state(skb);
	family = x->inner_mode->afinfo->family;

	if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
		return -EPERM;

	skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
	skb->dev = dev;

	tstats = this_cpu_ptr(dev->tstats);
	u64_stats_update_begin(&tstats->syncp);
	tstats->rx_packets++;
	tstats->rx_bytes += skb->len;
	u64_stats_update_end(&tstats->syncp);

	return 0;
}

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/**
 * 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);
}

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static bool vti6_state_check(const struct xfrm_state *x,
			     const struct in6_addr *dst,
			     const struct in6_addr *src)
{
	xfrm_address_t *daddr = (xfrm_address_t *)dst;
	xfrm_address_t *saddr = (xfrm_address_t *)src;

	/* if there is no transform then this tunnel is not functional.
	 * Or if the xfrm is not mode tunnel.
	 */
	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
	    x->props.family != AF_INET6)
		return false;

	if (ipv6_addr_any(dst))
		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);

	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
		return false;

	return true;
}

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/**
 * vti6_xmit - send a packet
 *   @skb: the outgoing socket buffer
 *   @dev: the outgoing tunnel device
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 *   @fl: the flow informations for the xfrm_lookup
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 **/
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static int
vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
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{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net_device_stats *stats = &t->dev->stats;
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	struct dst_entry *dst = skb_dst(skb);
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	struct net_device *tdev;
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	struct xfrm_state *x;
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	int err = -1;

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	if (!dst)
		goto tx_err_link_failure;
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	dst_hold(dst);
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	dst = xfrm_lookup(t->net, dst, fl, NULL, 0);
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	if (IS_ERR(dst)) {
		err = PTR_ERR(dst);
		dst = NULL;
		goto tx_err_link_failure;
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	}

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	x = dst->xfrm;
	if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
		goto tx_err_link_failure;

	if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
			      (const struct in6_addr *)&x->id.daddr))
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		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;
	}

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	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
	skb_dst_set(skb, dst);
	skb->dev = skb_dst(skb)->dev;
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	err = dst_output(skb);
	if (net_xmit_eval(err) == 0) {
		struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

		u64_stats_update_begin(&tstats->syncp);
		tstats->tx_bytes += skb->len;
		tstats->tx_packets++;
		u64_stats_update_end(&tstats->syncp);
	} else {
		stats->tx_errors++;
		stats->tx_aborted_errors++;
	}
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	return 0;
tx_err_link_failure:
	stats->tx_carrier_errors++;
	dst_link_failure(skb);
tx_err_dst_release:
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	dst_release(dst);
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	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;
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	struct ipv6hdr *ipv6h;
	struct flowi fl;
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	int ret;

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	memset(&fl, 0, sizeof(fl));
	skb->mark = be32_to_cpu(t->parms.o_key);

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	switch (skb->protocol) {
	case htons(ETH_P_IPV6):
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		ipv6h = ipv6_hdr(skb);

		if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
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		    vti6_addr_conflict(t, ipv6h))
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			goto tx_err;

		xfrm_decode_session(skb, &fl, AF_INET6);
		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
		break;
	case htons(ETH_P_IP):
		xfrm_decode_session(skb, &fl, AF_INET);
		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
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		break;
	default:
		goto tx_err;
	}

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	ret = vti6_xmit(skb, dev, &fl);
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	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;
}

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static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
		    u8 type, u8 code, int offset, __be32 info)
{
	__be32 spi;
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	__u32 mark;
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	struct xfrm_state *x;
	struct ip6_tnl *t;
	struct ip_esp_hdr *esph;
	struct ip_auth_hdr *ah;
	struct ip_comp_hdr *ipch;
	struct net *net = dev_net(skb->dev);
	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
	int protocol = iph->nexthdr;

	t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
	if (!t)
		return -1;

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	mark = be32_to_cpu(t->parms.o_key);

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	switch (protocol) {
	case IPPROTO_ESP:
		esph = (struct ip_esp_hdr *)(skb->data + offset);
		spi = esph->spi;
		break;
	case IPPROTO_AH:
		ah = (struct ip_auth_hdr *)(skb->data + offset);
		spi = ah->spi;
		break;
	case IPPROTO_COMP:
		ipch = (struct ip_comp_hdr *)(skb->data + offset);
		spi = htonl(ntohs(ipch->cpi));
		break;
	default:
		return 0;
	}

	if (type != ICMPV6_PKT_TOOBIG &&
	    type != NDISC_REDIRECT)
		return 0;

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	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
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			      spi, protocol, AF_INET6);
	if (!x)
		return 0;

	if (type == NDISC_REDIRECT)
		ip6_redirect(skb, net, skb->dev->ifindex, 0);
	else
		ip6_update_pmtu(skb, net, info, 0, 0);
	xfrm_state_put(x);

	return 0;
}

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static void vti6_link_config(struct ip6_tnl *t)
{
	struct net_device *dev = t->dev;
	struct __ip6_tnl_parm *p = &t->parms;

	memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));

	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;
}

/**
 * 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));
		}
719
		if (!t)
720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738
			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) {
739
			if (t) {
740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769
				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);
770
			if (!t)
771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804
				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 = {
805
	.ndo_init	= vti6_dev_init,
806 807 808 809
	.ndo_uninit	= vti6_dev_uninit,
	.ndo_start_xmit = vti6_tnl_xmit,
	.ndo_do_ioctl	= vti6_ioctl,
	.ndo_change_mtu = vti6_change_mtu,
810
	.ndo_get_stats64 = ip_tunnel_get_stats64,
811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829
};

/**
 * 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)
{
	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;
	dev->flags |= IFF_NOARP;
	dev->addr_len = sizeof(struct in6_addr);
830
	netif_keep_dst(dev);
831 832 833 834 835 836 837 838 839 840 841 842
}

/**
 * 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);
843
	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899
	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);

	t->parms.proto = IPPROTO_IPV6;
	dev_hold(dev);

	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])
900
		parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
901 902

	if (data[IFLA_VTI_REMOTE])
903
		parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928

	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);
}

929 930 931 932 933 934 935 936 937
static void vti6_dellink(struct net_device *dev, struct list_head *head)
{
	struct net *net = dev_net(dev);
	struct vti6_net *ip6n = net_generic(net, vti6_net_id);

	if (dev != ip6n->fb_tnl_dev)
		unregister_netdevice_queue(dev, head);
}

938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983
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) ||
984 985
	    nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
	    nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
	    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,
1011
	.dellink	= vti6_dellink,
1012 1013 1014
	.changelink	= vti6_changelink,
	.get_size	= vti6_get_size,
	.fill_info	= vti6_fill_info,
1015
	.get_link_net	= ip6_tnl_get_link_net,
1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
};

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]);
1026
		while (t) {
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047
			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",
1048
					NET_NAME_UNKNOWN, vti6_dev_setup);
1049 1050 1051 1052

	if (!ip6n->fb_tnl_dev)
		goto err_alloc_dev;
	dev_net_set(ip6n->fb_tnl_dev, net);
1053
	ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089

	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),
};

1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110
static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
	.handler	=	vti6_rcv,
	.cb_handler	=	vti6_rcv_cb,
	.err_handler	=	vti6_err,
	.priority	=	100,
};

1111 1112 1113 1114 1115 1116 1117
/**
 * vti6_tunnel_init - register protocol and reserve needed resources
 *
 * Return: 0 on success
 **/
static int __init vti6_tunnel_init(void)
{
1118 1119
	const char *msg;
	int err;
1120

1121
	msg = "tunnel device";
1122 1123
	err = register_pernet_device(&vti6_net_ops);
	if (err < 0)
1124
		goto pernet_dev_failed;
1125

1126
	msg = "tunnel protocols";
1127
	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1128 1129
	if (err < 0)
		goto xfrm_proto_esp_failed;
1130
	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1131 1132
	if (err < 0)
		goto xfrm_proto_ah_failed;
1133
	err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1134 1135
	if (err < 0)
		goto xfrm_proto_comp_failed;
1136

1137
	msg = "netlink interface";
1138 1139 1140 1141 1142 1143 1144
	err = rtnl_link_register(&vti6_link_ops);
	if (err < 0)
		goto rtnl_link_failed;

	return 0;

rtnl_link_failed:
1145
	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1146
xfrm_proto_comp_failed:
1147
	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1148
xfrm_proto_ah_failed:
1149
	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1150
xfrm_proto_esp_failed:
1151
	unregister_pernet_device(&vti6_net_ops);
1152 1153
pernet_dev_failed:
	pr_err("vti6 init: failed to register %s\n", msg);
1154 1155 1156 1157 1158 1159 1160 1161 1162
	return err;
}

/**
 * vti6_tunnel_cleanup - free resources and unregister protocol
 **/
static void __exit vti6_tunnel_cleanup(void)
{
	rtnl_link_unregister(&vti6_link_ops);
1163 1164 1165
	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1166 1167 1168 1169 1170 1171 1172 1173 1174 1175
	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");