linux/net/ipv4/ip_vti.c

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/*
* 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 <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);
/* We dont digest the packet therefore let the packet pass */
static int vti_rcv(struct sk_buff *skb)
{
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) {
struct pcpu_tstats *tstats;
vti: get rid of nf mark rule in prerouting This patch fixes and improves the use of vti interfaces (while lightly changing the way of configuring them). Currently: - it is necessary to identify and mark inbound IPsec packets destined to each vti interface, via netfilter rules in the mangle table at prerouting hook. - the vti module cannot retrieve the right tunnel in input since commit b9959fd3: vti tunnels all have an i_key, but the tunnel lookup is done with flag TUNNEL_NO_KEY, so there no chance to retrieve them. - the i_key is used by the outbound processing as a mark to lookup for the right SP and SA bundle. This patch uses the o_key to store the vti mark (instead of i_key) and enables: - to avoid the need for previously marking the inbound skbuffs via a netfilter rule. - to properly retrieve the right tunnel in input, only based on the IPsec packet outer addresses. - to properly perform an inbound policy check (using the tunnel o_key as a mark). - to properly perform an outbound SPD and SAD lookup (using the tunnel o_key as a mark). - to keep the current mark of the skbuff. The skbuff mark is neither used nor changed by the vti interface. Only the vti interface o_key is used. SAs have a wildcard mark. SPs have a mark equal to the vti interface o_key. The vti interface must be created as follows (i_key = 0, o_key = mark): ip link add vti1 mode vti local 1.1.1.1 remote 2.2.2.2 okey 1 The SPs attached to vti1 must be created as follows (mark = vti1 o_key): ip xfrm policy add dir out mark 1 tmpl src 1.1.1.1 dst 2.2.2.2 \ proto esp mode tunnel ip xfrm policy add dir in mark 1 tmpl src 2.2.2.2 dst 1.1.1.1 \ proto esp mode tunnel The SAs are created with the default wildcard mark. There is no distinction between global vs. vti SAs. Just their addresses will possibly link them to a vti interface: ip xfrm state add src 1.1.1.1 dst 2.2.2.2 proto esp spi 1000 mode tunnel \ enc "cbc(aes)" "azertyuiopqsdfgh" ip xfrm state add src 2.2.2.2 dst 1.1.1.1 proto esp spi 2000 mode tunnel \ enc "cbc(aes)" "sqbdhgqsdjqjsdfh" To avoid matching "global" (not vti) SPs in vti interfaces, global SPs should no use the default wildcard mark, but explicitly match mark 0. To avoid a double SPD lookup in input and output (in global and vti SPDs), the NOPOLICY and NOXFRM options should be set on the vti interfaces: echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_policy echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_xfrm The outgoing traffic is steered to vti1 by a route via the vti interface: ip route add 192.168.0.0/16 dev vti1 The incoming IPsec traffic is steered to vti1 because its outer addresses match the vti1 tunnel configuration. Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08 17:21:22 +02:00
u32 oldmark = skb->mark;
int ret;
vti: get rid of nf mark rule in prerouting This patch fixes and improves the use of vti interfaces (while lightly changing the way of configuring them). Currently: - it is necessary to identify and mark inbound IPsec packets destined to each vti interface, via netfilter rules in the mangle table at prerouting hook. - the vti module cannot retrieve the right tunnel in input since commit b9959fd3: vti tunnels all have an i_key, but the tunnel lookup is done with flag TUNNEL_NO_KEY, so there no chance to retrieve them. - the i_key is used by the outbound processing as a mark to lookup for the right SP and SA bundle. This patch uses the o_key to store the vti mark (instead of i_key) and enables: - to avoid the need for previously marking the inbound skbuffs via a netfilter rule. - to properly retrieve the right tunnel in input, only based on the IPsec packet outer addresses. - to properly perform an inbound policy check (using the tunnel o_key as a mark). - to properly perform an outbound SPD and SAD lookup (using the tunnel o_key as a mark). - to keep the current mark of the skbuff. The skbuff mark is neither used nor changed by the vti interface. Only the vti interface o_key is used. SAs have a wildcard mark. SPs have a mark equal to the vti interface o_key. The vti interface must be created as follows (i_key = 0, o_key = mark): ip link add vti1 mode vti local 1.1.1.1 remote 2.2.2.2 okey 1 The SPs attached to vti1 must be created as follows (mark = vti1 o_key): ip xfrm policy add dir out mark 1 tmpl src 1.1.1.1 dst 2.2.2.2 \ proto esp mode tunnel ip xfrm policy add dir in mark 1 tmpl src 2.2.2.2 dst 1.1.1.1 \ proto esp mode tunnel The SAs are created with the default wildcard mark. There is no distinction between global vs. vti SAs. Just their addresses will possibly link them to a vti interface: ip xfrm state add src 1.1.1.1 dst 2.2.2.2 proto esp spi 1000 mode tunnel \ enc "cbc(aes)" "azertyuiopqsdfgh" ip xfrm state add src 2.2.2.2 dst 1.1.1.1 proto esp spi 2000 mode tunnel \ enc "cbc(aes)" "sqbdhgqsdjqjsdfh" To avoid matching "global" (not vti) SPs in vti interfaces, global SPs should no use the default wildcard mark, but explicitly match mark 0. To avoid a double SPD lookup in input and output (in global and vti SPDs), the NOPOLICY and NOXFRM options should be set on the vti interfaces: echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_policy echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_xfrm The outgoing traffic is steered to vti1 by a route via the vti interface: ip route add 192.168.0.0/16 dev vti1 The incoming IPsec traffic is steered to vti1 because its outer addresses match the vti1 tunnel configuration. Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08 17:21:22 +02:00
/* temporarily mark the skb with the tunnel o_key, to
* only match policies with this mark.
*/
skb->mark = be32_to_cpu(tunnel->parms.o_key);
ret = xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb);
skb->mark = oldmark;
if (!ret)
return -1;
tstats = this_cpu_ptr(tunnel->dev->tstats);
u64_stats_update_begin(&tstats->syncp);
tstats->rx_packets++;
tstats->rx_bytes += skb->len;
u64_stats_update_end(&tstats->syncp);
secpath_reset(skb);
skb->dev = tunnel->dev;
return 1;
}
return -1;
}
/* 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 iphdr *tiph = &tunnel->parms.iph;
u8 tos;
struct rtable *rt; /* Route to the other host */
struct net_device *tdev; /* Device to other host */
struct iphdr *old_iph = ip_hdr(skb);
__be32 dst = tiph->daddr;
struct flowi4 fl4;
int err;
if (skb->protocol != htons(ETH_P_IP))
goto tx_error;
tos = old_iph->tos;
memset(&fl4, 0, sizeof(fl4));
flowi4_init_output(&fl4, tunnel->parms.link,
vti: get rid of nf mark rule in prerouting This patch fixes and improves the use of vti interfaces (while lightly changing the way of configuring them). Currently: - it is necessary to identify and mark inbound IPsec packets destined to each vti interface, via netfilter rules in the mangle table at prerouting hook. - the vti module cannot retrieve the right tunnel in input since commit b9959fd3: vti tunnels all have an i_key, but the tunnel lookup is done with flag TUNNEL_NO_KEY, so there no chance to retrieve them. - the i_key is used by the outbound processing as a mark to lookup for the right SP and SA bundle. This patch uses the o_key to store the vti mark (instead of i_key) and enables: - to avoid the need for previously marking the inbound skbuffs via a netfilter rule. - to properly retrieve the right tunnel in input, only based on the IPsec packet outer addresses. - to properly perform an inbound policy check (using the tunnel o_key as a mark). - to properly perform an outbound SPD and SAD lookup (using the tunnel o_key as a mark). - to keep the current mark of the skbuff. The skbuff mark is neither used nor changed by the vti interface. Only the vti interface o_key is used. SAs have a wildcard mark. SPs have a mark equal to the vti interface o_key. The vti interface must be created as follows (i_key = 0, o_key = mark): ip link add vti1 mode vti local 1.1.1.1 remote 2.2.2.2 okey 1 The SPs attached to vti1 must be created as follows (mark = vti1 o_key): ip xfrm policy add dir out mark 1 tmpl src 1.1.1.1 dst 2.2.2.2 \ proto esp mode tunnel ip xfrm policy add dir in mark 1 tmpl src 2.2.2.2 dst 1.1.1.1 \ proto esp mode tunnel The SAs are created with the default wildcard mark. There is no distinction between global vs. vti SAs. Just their addresses will possibly link them to a vti interface: ip xfrm state add src 1.1.1.1 dst 2.2.2.2 proto esp spi 1000 mode tunnel \ enc "cbc(aes)" "azertyuiopqsdfgh" ip xfrm state add src 2.2.2.2 dst 1.1.1.1 proto esp spi 2000 mode tunnel \ enc "cbc(aes)" "sqbdhgqsdjqjsdfh" To avoid matching "global" (not vti) SPs in vti interfaces, global SPs should no use the default wildcard mark, but explicitly match mark 0. To avoid a double SPD lookup in input and output (in global and vti SPDs), the NOPOLICY and NOXFRM options should be set on the vti interfaces: echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_policy echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_xfrm The outgoing traffic is steered to vti1 by a route via the vti interface: ip route add 192.168.0.0/16 dev vti1 The incoming IPsec traffic is steered to vti1 because its outer addresses match the vti1 tunnel configuration. Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08 17:21:22 +02:00
be32_to_cpu(tunnel->parms.o_key), RT_TOS(tos),
RT_SCOPE_UNIVERSE,
IPPROTO_IPIP, 0,
dst, tiph->saddr, 0, 0);
rt = ip_route_output_key(dev_net(dev), &fl4);
if (IS_ERR(rt)) {
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
/* if there is no transform then this tunnel is not functional.
* Or if the xfrm is not mode tunnel.
*/
if (!rt->dst.xfrm ||
rt->dst.xfrm->props.mode != XFRM_MODE_TUNNEL) {
dev->stats.tx_carrier_errors++;
ip_rt_put(rt);
goto tx_error_icmp;
}
tdev = rt->dst.dev;
if (tdev == dev) {
ip_rt_put(rt);
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;
}
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
nf_reset(skb);
skb->dev = skb_dst(skb)->dev;
err = dst_output(skb);
if (net_xmit_eval(err) == 0)
err = skb->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++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
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;
}
err = ip_tunnel_ioctl(dev, &p, cmd);
if (err)
return err;
if (cmd != SIOCDELTUNNEL) {
p.i_flags |= GRE_KEY | VTI_ISVTI;
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;
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->type = ARPHRD_TUNNEL;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
dev->mtu = ETH_DATA_LEN;
dev->flags = IFF_NOARP;
dev->iflink = 0;
dev->addr_len = 4;
dev->features |= NETIF_F_NETNS_LOCAL;
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 xfrm_tunnel_notifier vti_handler __read_mostly = {
.handler = vti_rcv,
.priority = 1,
};
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;
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,
.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_mode_tunnel_input_register(&vti_handler);
if (err < 0) {
unregister_pernet_device(&vti_net_ops);
pr_info("vti init: can't register tunnel\n");
}
err = rtnl_link_register(&vti_link_ops);
if (err < 0)
goto rtnl_link_failed;
return err;
rtnl_link_failed:
xfrm4_mode_tunnel_input_deregister(&vti_handler);
unregister_pernet_device(&vti_net_ops);
return err;
}
static void __exit vti_fini(void)
{
rtnl_link_unregister(&vti_link_ops);
if (xfrm4_mode_tunnel_input_deregister(&vti_handler))
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");