234 lines
5.6 KiB
C
234 lines
5.6 KiB
C
/*
|
|
* mpls tunnels An implementation mpls tunnels using the light weight tunnel
|
|
* infrastructure
|
|
*
|
|
* Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
|
|
*
|
|
* 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/types.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/net.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mpls.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <net/ip.h>
|
|
#include <net/dst.h>
|
|
#include <net/lwtunnel.h>
|
|
#include <net/netevent.h>
|
|
#include <net/netns/generic.h>
|
|
#include <net/ip6_fib.h>
|
|
#include <net/route.h>
|
|
#include <net/mpls_iptunnel.h>
|
|
#include <linux/mpls_iptunnel.h>
|
|
#include "internal.h"
|
|
|
|
static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
|
|
[MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en)
|
|
{
|
|
/* The size of the layer 2.5 labels to be added for this route */
|
|
return en->labels * sizeof(struct mpls_shim_hdr);
|
|
}
|
|
|
|
int mpls_output(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
struct mpls_shim_hdr *hdr;
|
|
struct net_device *out_dev;
|
|
unsigned int hh_len;
|
|
unsigned int new_header_size;
|
|
unsigned int mtu;
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct rtable *rt = NULL;
|
|
struct rt6_info *rt6 = NULL;
|
|
struct lwtunnel_state *lwtstate = NULL;
|
|
int err = 0;
|
|
bool bos;
|
|
int i;
|
|
unsigned int ttl;
|
|
|
|
/* Obtain the ttl */
|
|
if (skb->protocol == htons(ETH_P_IP)) {
|
|
ttl = ip_hdr(skb)->ttl;
|
|
rt = (struct rtable *)dst;
|
|
lwtstate = rt->rt_lwtstate;
|
|
} else if (skb->protocol == htons(ETH_P_IPV6)) {
|
|
ttl = ipv6_hdr(skb)->hop_limit;
|
|
rt6 = (struct rt6_info *)dst;
|
|
lwtstate = rt6->rt6i_lwtstate;
|
|
} else {
|
|
goto drop;
|
|
}
|
|
|
|
skb_orphan(skb);
|
|
|
|
/* Find the output device */
|
|
out_dev = dst->dev;
|
|
if (!mpls_output_possible(out_dev) ||
|
|
!lwtstate || skb_warn_if_lro(skb))
|
|
goto drop;
|
|
|
|
skb_forward_csum(skb);
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(lwtstate);
|
|
|
|
/* Verify the destination can hold the packet */
|
|
new_header_size = mpls_encap_size(tun_encap_info);
|
|
mtu = mpls_dev_mtu(out_dev);
|
|
if (mpls_pkt_too_big(skb, mtu - new_header_size))
|
|
goto drop;
|
|
|
|
hh_len = LL_RESERVED_SPACE(out_dev);
|
|
if (!out_dev->header_ops)
|
|
hh_len = 0;
|
|
|
|
/* Ensure there is enough space for the headers in the skb */
|
|
if (skb_cow(skb, hh_len + new_header_size))
|
|
goto drop;
|
|
|
|
skb_push(skb, new_header_size);
|
|
skb_reset_network_header(skb);
|
|
|
|
skb->dev = out_dev;
|
|
skb->protocol = htons(ETH_P_MPLS_UC);
|
|
|
|
/* Push the new labels */
|
|
hdr = mpls_hdr(skb);
|
|
bos = true;
|
|
for (i = tun_encap_info->labels - 1; i >= 0; i--) {
|
|
hdr[i] = mpls_entry_encode(tun_encap_info->label[i],
|
|
ttl, 0, bos);
|
|
bos = false;
|
|
}
|
|
|
|
if (rt)
|
|
err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway,
|
|
skb);
|
|
else if (rt6)
|
|
err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
|
|
skb);
|
|
if (err)
|
|
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
|
|
__func__, err);
|
|
|
|
return 0;
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int mpls_build_state(struct net_device *dev, struct nlattr *nla,
|
|
struct lwtunnel_state **ts)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
|
|
struct lwtunnel_state *newts;
|
|
int tun_encap_info_len;
|
|
int ret;
|
|
|
|
ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla,
|
|
mpls_iptunnel_policy);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!tb[MPLS_IPTUNNEL_DST])
|
|
return -EINVAL;
|
|
|
|
tun_encap_info_len = sizeof(*tun_encap_info);
|
|
|
|
newts = lwtunnel_state_alloc(tun_encap_info_len);
|
|
if (!newts)
|
|
return -ENOMEM;
|
|
|
|
newts->len = tun_encap_info_len;
|
|
tun_encap_info = mpls_lwtunnel_encap(newts);
|
|
ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
|
|
&tun_encap_info->labels, tun_encap_info->label);
|
|
if (ret)
|
|
goto errout;
|
|
newts->type = LWTUNNEL_ENCAP_MPLS;
|
|
newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
|
|
|
|
*ts = newts;
|
|
|
|
return 0;
|
|
|
|
errout:
|
|
kfree(newts);
|
|
*ts = NULL;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mpls_fill_encap_info(struct sk_buff *skb,
|
|
struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(lwtstate);
|
|
|
|
if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels,
|
|
tun_encap_info->label))
|
|
goto nla_put_failure;
|
|
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(lwtstate);
|
|
|
|
return nla_total_size(tun_encap_info->labels * 4);
|
|
}
|
|
|
|
static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
|
|
{
|
|
struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a);
|
|
struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b);
|
|
int l;
|
|
|
|
if (a_hdr->labels != b_hdr->labels)
|
|
return 1;
|
|
|
|
for (l = 0; l < MAX_NEW_LABELS; l++)
|
|
if (a_hdr->label[l] != b_hdr->label[l])
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static const struct lwtunnel_encap_ops mpls_iptun_ops = {
|
|
.build_state = mpls_build_state,
|
|
.output = mpls_output,
|
|
.fill_encap = mpls_fill_encap_info,
|
|
.get_encap_size = mpls_encap_nlsize,
|
|
.cmp_encap = mpls_encap_cmp,
|
|
};
|
|
|
|
static int __init mpls_iptunnel_init(void)
|
|
{
|
|
return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
|
|
}
|
|
module_init(mpls_iptunnel_init);
|
|
|
|
static void __exit mpls_iptunnel_exit(void)
|
|
{
|
|
lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
|
|
}
|
|
module_exit(mpls_iptunnel_exit);
|
|
|
|
MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
|
|
MODULE_LICENSE("GPL v2");
|