// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Linux NET3: IP/IP protocol decoder modified to support
* virtual tunnel interface
*
* Authors:
* Saurabh Mohan ([email protected]) 05/07/2012
*/
/*
This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
For comments look at net/ipv4/ip_gre.c --ANK
*/
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/uaccess.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/netfilter_ipv4.h>
#include <linux/if_ether.h>
#include <linux/icmpv6.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/ip_tunnels.h>
#include <net/inet_ecn.h>
#include <net/xfrm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
static struct rtnl_link_ops vti_link_ops __read_mostly;
static unsigned int vti_net_id __read_mostly;
static int vti_tunnel_init(struct net_device *dev);
static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
int encap_type, bool update_skb_dev)
{
struct ip_tunnel *tunnel;
const struct iphdr *iph = ip_hdr(skb);
struct net *net = dev_net(skb->dev);
struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
IP_TUNNEL_DECLARE_FLAGS(flags) = { };
__set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
iph->saddr, iph->daddr, 0);
if (tunnel) {
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto drop;
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
if (update_skb_dev)
skb->dev = tunnel->dev;
return xfrm_input(skb, nexthdr, spi, encap_type);
}
return -EINVAL;
drop:
kfree_skb(skb);
return 0;
}
static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
int encap_type)
{
return vti_input(skb, nexthdr, spi, encap_type, false);
}
static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev)
{
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev);
}
static int vti_rcv_proto(struct sk_buff *skb)
{
return vti_rcv(skb, 0, false);
}
static int vti_rcv_cb(struct sk_buff *skb, int err)
{
unsigned short family;
struct net_device *dev;
struct xfrm_state *x;
const struct xfrm_mode *inner_mode;
struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
u32 orig_mark = skb->mark;
int ret;
if (!tunnel)
return 1;
dev = tunnel->dev;
if (err) {
DEV_STATS_INC(dev, rx_errors);
DEV_STATS_INC(dev, rx_dropped);
return 0;
}
x = xfrm_input_state(skb);
inner_mode = &x->inner_mode;
if (x->sel.family == AF_UNSPEC) {
inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
if (inner_mode == NULL) {
XFRM_INC_STATS(dev_net(skb->dev),
LINUX_MIB_XFRMINSTATEMODEERROR);
return -EINVAL;
}
}
family = inner_mode->family;
skb->mark = be32_to_cpu(tunnel->parms.i_key);
ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
skb->mark = orig_mark;
if (!ret)
return -EPERM;
skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
skb->dev = dev;
dev_sw_netstats_rx_add(dev, skb->len);
return 0;
}
static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 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_INET)
return false;
if (!dst)
return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
return false;
return true;
}
static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
struct flowi *fl)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct ip_tunnel_parm_kern *parms = &tunnel->parms;
struct dst_entry *dst = skb_dst(skb);
struct net_device *tdev; /* Device to other host */
int pkt_len = skb->len;
int err;
int mtu;
if (!dst) {
switch (skb->protocol) {
case htons(ETH_P_IP): {
struct rtable *rt;
fl->u.ip4.flowi4_oif = dev->ifindex;
fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
if (IS_ERR(rt)) {
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
dst = &rt->dst;
skb_dst_set(skb, dst);
break;
}
#if IS_ENABLED(CONFIG_IPV6)
case htons(ETH_P_IPV6):
fl->u.ip6.flowi6_oif = dev->ifindex;
fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
if (dst->error) {
dst_release(dst);
dst = NULL;
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
skb_dst_set(skb, dst);
break;
#endif
default:
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
}
dst_hold(dst);
dst = xfrm_lookup_route(tunnel->net, dst, fl, NULL, 0);
if (IS_ERR(dst)) {
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
if (dst->flags & DST_XFRM_QUEUE)
goto xmit;
if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
DEV_STATS_INC(dev, tx_carrier_errors);
dst_release(dst);
goto tx_error_icmp;
}
tdev = dst->dev;
if (tdev == dev) {
dst_release(dst);
DEV_STATS_INC(dev, collisions);
goto tx_error;
}
mtu = dst_mtu(dst);
if (skb->len > mtu) {
skb_dst_update_pmtu_no_confirm(skb, mtu);
if (skb->protocol == htons(ETH_P_IP)) {
if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
goto xmit;
icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
} else {
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
}
dst_release(dst);
goto tx_error;
}
xmit:
skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
skb_dst_set(skb, dst);
skb->dev = skb_dst(skb)->dev;
err = dst_output(tunnel->net, skb->sk, skb);
if (net_xmit_eval(err) == 0)
err = pkt_len;
iptunnel_xmit_stats(dev, err);
return NETDEV_TX_OK;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
DEV_STATS_INC(dev, tx_errors);
kfree_skb(skb);
return NETDEV_TX_OK;
}
/* This function assumes it is being called from dev_queue_xmit()
* and that skb is filled properly by that function.
*/
static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct flowi fl;
if (!pskb_inet_may_pull(skb))
goto tx_err;
memset(&fl, 0, sizeof(fl));
switch (skb->protocol) {
case htons(ETH_P_IP):
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET);
break;
case htons(ETH_P_IPV6):
memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6);
break;
default:
goto tx_err;
}
/* override mark with tunnel output key */
fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
return vti_xmit(skb, dev, &fl);
tx_err:
DEV_STATS_INC(dev, tx_errors);
kfree_skb(skb);
return NETDEV_TX_OK;
}
static int vti4_err(struct sk_buff *skb, u32 info)
{
__be32 spi;
__u32 mark;
struct xfrm_state *x;
struct ip_tunnel *tunnel;
struct ip_esp_hdr *esph;
struct ip_auth_hdr *ah ;
struct ip_comp_hdr *ipch;
struct net *net = dev_net(skb->dev);
const struct iphdr *iph = (const struct iphdr *)skb->data;
int protocol = iph->protocol;
struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
IP_TUNNEL_DECLARE_FLAGS(flags) = { };
__set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
iph->daddr, iph->saddr, 0);
if (!tunnel)
return -1;
mark = be32_to_cpu(tunnel->parms.o_key);
switch (protocol) {
case IPPROTO_ESP:
esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
spi = esph->spi;
break;
case IPPROTO_AH:
ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
spi = ah->spi;
break;
case IPPROTO_COMP:
ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
spi = htonl(ntohs(ipch->cpi));
break;
default:
return 0;
}
switch (icmp_hdr(skb)->type) {
case ICMP_DEST_UNREACH:
if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
return 0;
break;
case ICMP_REDIRECT:
break;
default:
return 0;
}
x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
spi, protocol, AF_INET);
if (!x)
return 0;
if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
ipv4_update_pmtu(skb, net, info, 0, protocol);
else
ipv4_redirect(skb, net, 0, protocol);
xfrm_state_put(x);
return 0;
}
static int
vti_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p, int cmd)
{
IP_TUNNEL_DECLARE_FLAGS(flags) = { };
int err = 0;
if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
if (p->iph.version != 4 || p->iph.protocol != IPPROTO_IPIP ||
p->iph.ihl != 5)
return -EINVAL;
}
if (!ip_tunnel_flags_is_be16_compat(p->i_flags) ||
!ip_tunnel_flags_is_be16_compat(p->o_flags))
return -EOVERFLOW;
if (!(ip_tunnel_flags_to_be16(p->i_flags) & GRE_KEY))
p->i_key = 0;
if (!(ip_tunnel_flags_to_be16(p->o_flags) & GRE_KEY))
p->o_key = 0;
__set_bit(IP_TUNNEL_VTI_BIT, flags);
ip_tunnel_flags_copy(p->i_flags, flags);
err = ip_tunnel_ctl(dev, p, cmd);
if (err)
return err;
if (cmd != SIOCDELTUNNEL) {
ip_tunnel_flags_from_be16(flags, GRE_KEY);
ip_tunnel_flags_or(p->i_flags, p->i_flags, flags);
ip_tunnel_flags_or(p->o_flags, p->o_flags, flags);
}
return 0;
}
static const struct net_device_ops vti_netdev_ops = {
.ndo_init = vti_tunnel_init,
.ndo_uninit = ip_tunnel_uninit,
.ndo_start_xmit = vti_tunnel_xmit,
.ndo_siocdevprivate = ip_tunnel_siocdevprivate,
.ndo_change_mtu = ip_tunnel_change_mtu,
.ndo_get_stats64 = dev_get_tstats64,
.ndo_get_iflink = ip_tunnel_get_iflink,
.ndo_tunnel_ctl = vti_tunnel_ctl,
};
static void vti_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &vti_netdev_ops;
dev->header_ops = &ip_tunnel_header_ops;
dev->type = ARPHRD_TUNNEL;
ip_tunnel_setup(dev, vti_net_id);
}
static int vti_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct iphdr *iph = &tunnel->parms.iph;
__dev_addr_set(dev, &iph->saddr, 4);
memcpy(dev->broadcast, &iph->daddr, 4);
dev->flags = IFF_NOARP;
dev->addr_len = 4;
dev->lltx = true;
netif_keep_dst(dev);
return ip_tunnel_init(dev);
}
static void __net_init vti_fb_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct iphdr *iph = &tunnel->parms.iph;
iph->version = 4;
iph->protocol = IPPROTO_IPIP;
iph->ihl = 5;
}
static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
.handler = vti_rcv_proto,
.input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
.handler = vti_rcv_proto,
.input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
.handler = vti_rcv_proto,
.input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
static int vti_rcv_tunnel(struct sk_buff *skb)
{
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
return vti_input(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr, 0, false);
}
static struct xfrm_tunnel vti_ipip_handler __read_mostly = {
.handler = vti_rcv_tunnel,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 0,
};
#if IS_ENABLED(CONFIG_IPV6)
static struct xfrm_tunnel vti_ipip6_handler __read_mostly = {
.handler = vti_rcv_tunnel,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 0,
};
#endif
#endif
static int __net_init vti_init_net(struct net *net)
{
int err;
struct ip_tunnel_net *itn;
err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
if (err)
return err;
itn = net_generic(net, vti_net_id);
if (itn->fb_tunnel_dev)
vti_fb_tunnel_init(itn->fb_tunnel_dev);
return 0;
}
static void __net_exit vti_exit_batch_rtnl(struct list_head *list_net,
struct list_head *dev_to_kill)
{
ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops,
dev_to_kill);
}
static struct pernet_operations vti_net_ops = {
.init = vti_init_net,
.exit_batch_rtnl = vti_exit_batch_rtnl,
.id = &vti_net_id,
.size = sizeof(struct ip_tunnel_net),
};
static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
return 0;
}
static void vti_netlink_parms(struct nlattr *data[],
struct ip_tunnel_parm_kern *parms,
__u32 *fwmark)
{
memset(parms, 0, sizeof(*parms));
parms->iph.protocol = IPPROTO_IPIP;
if (!data)
return;
__set_bit(IP_TUNNEL_VTI_BIT, parms->i_flags);
if (data[IFLA_VTI_LINK])
parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
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]);
if (data[IFLA_VTI_LOCAL])
parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
if (data[IFLA_VTI_REMOTE])
parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
if (data[IFLA_VTI_FWMARK])
*fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
}
static int vti_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct ip_tunnel_parm_kern parms;
__u32 fwmark = 0;
vti_netlink_parms(data, &parms, &fwmark);
return ip_tunnel_newlink(dev, tb, &parms, fwmark);
}
static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_parm_kern p;
__u32 fwmark = t->fwmark;
vti_netlink_parms(data, &p, &fwmark);
return ip_tunnel_changelink(dev, tb, &p, fwmark);
}
static size_t vti_get_size(const struct net_device *dev)
{
return
/* IFLA_VTI_LINK */
nla_total_size(4) +
/* IFLA_VTI_IKEY */
nla_total_size(4) +
/* IFLA_VTI_OKEY */
nla_total_size(4) +
/* IFLA_VTI_LOCAL */
nla_total_size(4) +
/* IFLA_VTI_REMOTE */
nla_total_size(4) +
/* IFLA_VTI_FWMARK */
nla_total_size(4) +
0;
}
static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_parm_kern *p = &t->parms;
if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
return -EMSGSIZE;
return 0;
}
static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
[IFLA_VTI_LINK] = { .type = NLA_U32 },
[IFLA_VTI_IKEY] = { .type = NLA_U32 },
[IFLA_VTI_OKEY] = { .type = NLA_U32 },
[IFLA_VTI_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
[IFLA_VTI_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
[IFLA_VTI_FWMARK] = { .type = NLA_U32 },
};
static struct rtnl_link_ops vti_link_ops __read_mostly = {
.kind = "vti",
.maxtype = IFLA_VTI_MAX,
.policy = vti_policy,
.priv_size = sizeof(struct ip_tunnel),
.setup = vti_tunnel_setup,
.validate = vti_tunnel_validate,
.newlink = vti_newlink,
.changelink = vti_changelink,
.dellink = ip_tunnel_dellink,
.get_size = vti_get_size,
.fill_info = vti_fill_info,
.get_link_net = ip_tunnel_get_link_net,
};
static int __init vti_init(void)
{
const char *msg;
int err;
pr_info("IPv4 over IPsec tunneling driver\n");
msg = "tunnel device";
err = register_pernet_device(&vti_net_ops);
if (err < 0)
goto pernet_dev_failed;
msg = "tunnel protocols";
err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
if (err < 0)
goto xfrm_proto_esp_failed;
err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
if (err < 0)
goto xfrm_proto_ah_failed;
err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
if (err < 0)
goto xfrm_proto_comp_failed;
#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
msg = "ipip tunnel";
err = xfrm4_tunnel_register(&vti_ipip_handler, AF_INET);
if (err < 0)
goto xfrm_tunnel_ipip_failed;
#if IS_ENABLED(CONFIG_IPV6)
err = xfrm4_tunnel_register(&vti_ipip6_handler, AF_INET6);
if (err < 0)
goto xfrm_tunnel_ipip6_failed;
#endif
#endif
msg = "netlink interface";
err = rtnl_link_register(&vti_link_ops);
if (err < 0)
goto rtnl_link_failed;
return err;
rtnl_link_failed:
#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
#if IS_ENABLED(CONFIG_IPV6)
xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6);
xfrm_tunnel_ipip6_failed:
#endif
xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET);
xfrm_tunnel_ipip_failed:
#endif
xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
xfrm_proto_comp_failed:
xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
xfrm_proto_ah_failed:
xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
xfrm_proto_esp_failed:
unregister_pernet_device(&vti_net_ops);
pernet_dev_failed:
pr_err("vti init: failed to register %s\n", msg);
return err;
}
static void __exit vti_fini(void)
{
rtnl_link_unregister(&vti_link_ops);
#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
#if IS_ENABLED(CONFIG_IPV6)
xfrm4_tunnel_deregister(&vti_ipip6_handler, AF_INET6);
#endif
xfrm4_tunnel_deregister(&vti_ipip_handler, AF_INET);
#endif
xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
unregister_pernet_device(&vti_net_ops);
}
module_init(vti_init);
module_exit(vti_fini);
MODULE_DESCRIPTION("Virtual (secure) IP tunneling library");
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("vti");
MODULE_ALIAS_NETDEV("ip_vti0");
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