blob: 778ee1bf40aded1fc0ed53b7b7b7cefd9e25c1a9 [file] [log] [blame]
/*
* Linux NET3: IP/IP protocol decoder modified to support
* virtual tunnel interface
*
* Authors:
* Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
*
* 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.
*
*/
/*
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/mroute.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 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)
{
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);
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
iph->saddr, iph->daddr, 0);
if (tunnel != NULL) {
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto drop;
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
skb->mark = be32_to_cpu(tunnel->parms.i_key);
return xfrm_input(skb, nexthdr, spi, encap_type);
}
return -EINVAL;
drop:
kfree_skb(skb);
return 0;
}
static int vti_rcv(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, ip_hdr(skb)->protocol, 0, 0);
}
static int vti_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 ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
if (!tunnel)
return 1;
dev = tunnel->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(tunnel->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;
}
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 *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;
if (!dst) {
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
dst_hold(dst);
dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
if (IS_ERR(dst)) {
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
dev->stats.tx_carrier_errors++;
dst_release(dst);
goto tx_error_icmp;
}
tdev = dst->dev;
if (tdev == dev) {
dst_release(dst);
dev->stats.collisions++;
goto tx_error;
}
if (tunnel->err_count > 0) {
if (time_before(jiffies,
tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
tunnel->err_count--;
dst_link_failure(skb);
} else
tunnel->err_count = 0;
}
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(skb);
if (net_xmit_eval(err) == 0)
err = pkt_len;
iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
return NETDEV_TX_OK;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
dev->stats.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;
memset(&fl, 0, sizeof(fl));
skb->mark = be32_to_cpu(tunnel->parms.o_key);
switch (skb->protocol) {
case htons(ETH_P_IP):
xfrm_decode_session(skb, &fl, AF_INET);
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
break;
case htons(ETH_P_IPV6):
xfrm_decode_session(skb, &fl, AF_INET6);
memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
break;
default:
dev->stats.tx_errors++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
return vti_xmit(skb, dev, &fl);
}
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);
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
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;
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, 0, protocol, 0);
else
ipv4_redirect(skb, net, 0, 0, protocol, 0);
xfrm_state_put(x);
return 0;
}
static int
vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
int err = 0;
struct ip_tunnel_parm p;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
return -EFAULT;
if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
p.iph.ihl != 5)
return -EINVAL;
}
if (!(p.i_flags & GRE_KEY))
p.i_key = 0;
if (!(p.o_flags & GRE_KEY))
p.o_key = 0;
p.i_flags = VTI_ISVTI;
err = ip_tunnel_ioctl(dev, &p, cmd);
if (err)
return err;
if (cmd != SIOCDELTUNNEL) {
p.i_flags |= GRE_KEY;
p.o_flags |= GRE_KEY;
}
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
return -EFAULT;
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_do_ioctl = vti_tunnel_ioctl,
.ndo_change_mtu = ip_tunnel_change_mtu,
.ndo_get_stats64 = ip_tunnel_get_stats64,
};
static void vti_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &vti_netdev_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;
memcpy(dev->dev_addr, &iph->saddr, 4);
memcpy(dev->broadcast, &iph->daddr, 4);
dev->mtu = ETH_DATA_LEN;
dev->flags = IFF_NOARP;
dev->iflink = 0;
dev->addr_len = 4;
dev->features |= NETIF_F_LLTX;
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
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,
.input_handler = vti_input,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
.handler = vti_rcv,
.input_handler = vti_input,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
.handler = vti_rcv,
.input_handler = vti_input,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};
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);
vti_fb_tunnel_init(itn->fb_tunnel_dev);
return 0;
}
static void __net_exit vti_exit_net(struct net *net)
{
struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
ip_tunnel_delete_net(itn, &vti_link_ops);
}
static struct pernet_operations vti_net_ops = {
.init = vti_init_net,
.exit = vti_exit_net,
.id = &vti_net_id,
.size = sizeof(struct ip_tunnel_net),
};
static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
{
return 0;
}
static void vti_netlink_parms(struct nlattr *data[],
struct ip_tunnel_parm *parms)
{
memset(parms, 0, sizeof(*parms));
parms->iph.protocol = IPPROTO_IPIP;
if (!data)
return;
parms->i_flags = VTI_ISVTI;
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_be32(data[IFLA_VTI_LOCAL]);
if (data[IFLA_VTI_REMOTE])
parms->iph.daddr = nla_get_be32(data[IFLA_VTI_REMOTE]);
}
static int vti_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct ip_tunnel_parm parms;
vti_netlink_parms(data, &parms);
return ip_tunnel_newlink(dev, tb, &parms);
}
static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[])
{
struct ip_tunnel_parm p;
vti_netlink_parms(data, &p);
return ip_tunnel_changelink(dev, tb, &p);
}
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) +
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 *p = &t->parms;
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_be32(skb, IFLA_VTI_LOCAL, p->iph.saddr);
nla_put_be32(skb, IFLA_VTI_REMOTE, p->iph.daddr);
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 = FIELD_SIZEOF(struct iphdr, saddr) },
[IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
};
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,
};
static int __init vti_init(void)
{
int err;
pr_info("IPv4 over IPSec tunneling driver\n");
err = register_pernet_device(&vti_net_ops);
if (err < 0)
return err;
err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
if (err < 0) {
unregister_pernet_device(&vti_net_ops);
pr_info("vti init: can't register tunnel\n");
return err;
}
err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
if (err < 0) {
xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
unregister_pernet_device(&vti_net_ops);
pr_info("vti init: can't register tunnel\n");
return err;
}
err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
if (err < 0) {
xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
unregister_pernet_device(&vti_net_ops);
pr_info("vti init: can't register tunnel\n");
return err;
}
err = rtnl_link_register(&vti_link_ops);
if (err < 0)
goto rtnl_link_failed;
return err;
rtnl_link_failed:
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);
return err;
}
static void __exit vti_fini(void)
{
rtnl_link_unregister(&vti_link_ops);
if (xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP))
pr_info("vti close: can't deregister tunnel\n");
if (xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH))
pr_info("vti close: can't deregister tunnel\n");
if (xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP))
pr_info("vti close: can't deregister tunnel\n");
unregister_pernet_device(&vti_net_ops);
}
module_init(vti_init);
module_exit(vti_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("vti");
MODULE_ALIAS_NETDEV("ip_vti0");