Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.9 / 3e515645b198ac60f493822f9193dd8107e1b8d0 / . / net / mpls / af_mpls.c
blob: 4b3b9b310c3a00baba320d4071ea98d108a79d48 [file] [log] [blame]
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/sysctl.h>
#include <linux/net.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/mpls.h>
#include <linux/vmalloc.h>
#include <net/ip.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/arp.h>
#include <net/ip_fib.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#endif
#include <net/nexthop.h>
#include "internal.h"
/* Maximum number of labels to look ahead at when selecting a path of
* a multipath route
*/
#define MAX_MP_SELECT_LABELS 4
static int zero = 0;
static int label_limit = (1 << 20) - 1;
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
struct nlmsghdr *nlh, struct net *net, u32 portid,
unsigned int nlm_flags);
static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
{
struct mpls_route *rt = NULL;
if (index < net->mpls.platform_labels) {
struct mpls_route __rcu **platform_label =
rcu_dereference(net->mpls.platform_label);
rt = rcu_dereference(platform_label[index]);
}
return rt;
}
static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
{
return rcu_dereference_rtnl(dev->mpls_ptr);
}
bool mpls_output_possible(const struct net_device *dev)
{
return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
}
EXPORT_SYMBOL_GPL(mpls_output_possible);
static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
{
u8 *nh0_via = PTR_ALIGN((u8 *)&rt->rt_nh[rt->rt_nhn], VIA_ALEN_ALIGN);
int nh_index = nh - rt->rt_nh;
return nh0_via + rt->rt_max_alen * nh_index;
}
static const u8 *mpls_nh_via(const struct mpls_route *rt,
const struct mpls_nh *nh)
{
return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
}
static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
{
/* The size of the layer 2.5 labels to be added for this route */
return nh->nh_labels * sizeof(struct mpls_shim_hdr);
}
unsigned int mpls_dev_mtu(const struct net_device *dev)
{
/* The amount of data the layer 2 frame can hold */
return dev->mtu;
}
EXPORT_SYMBOL_GPL(mpls_dev_mtu);
bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
{
if (skb->len <= mtu)
return false;
if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
return false;
return true;
}
EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
static u32 mpls_multipath_hash(struct mpls_route *rt,
struct sk_buff *skb, bool bos)
{
struct mpls_entry_decoded dec;
struct mpls_shim_hdr *hdr;
bool eli_seen = false;
int label_index;
u32 hash = 0;
for (label_index = 0; label_index < MAX_MP_SELECT_LABELS && !bos;
label_index++) {
if (!pskb_may_pull(skb, sizeof(*hdr) * label_index))
break;
/* Read and decode the current label */
hdr = mpls_hdr(skb) + label_index;
dec = mpls_entry_decode(hdr);
/* RFC6790 - reserved labels MUST NOT be used as keys
* for the load-balancing function
*/
if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
hash = jhash_1word(dec.label, hash);
/* The entropy label follows the entropy label
* indicator, so this means that the entropy
* label was just added to the hash - no need to
* go any deeper either in the label stack or in the
* payload
*/
if (eli_seen)
break;
} else if (dec.label == MPLS_LABEL_ENTROPY) {
eli_seen = true;
}
bos = dec.bos;
if (bos && pskb_may_pull(skb, sizeof(*hdr) * label_index +
sizeof(struct iphdr))) {
const struct iphdr *v4hdr;
v4hdr = (const struct iphdr *)(mpls_hdr(skb) +
label_index);
if (v4hdr->version == 4) {
hash = jhash_3words(ntohl(v4hdr->saddr),
ntohl(v4hdr->daddr),
v4hdr->protocol, hash);
} else if (v4hdr->version == 6 &&
pskb_may_pull(skb, sizeof(*hdr) * label_index +
sizeof(struct ipv6hdr))) {
const struct ipv6hdr *v6hdr;
v6hdr = (const struct ipv6hdr *)(mpls_hdr(skb) +
label_index);
hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
hash = jhash_1word(v6hdr->nexthdr, hash);
}
}
}
return hash;
}
static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
struct sk_buff *skb, bool bos)
{
int alive = ACCESS_ONCE(rt->rt_nhn_alive);
u32 hash = 0;
int nh_index = 0;
int n = 0;
/* No need to look further into packet if there's only
* one path
*/
if (rt->rt_nhn == 1)
goto out;
if (alive <= 0)
return NULL;
hash = mpls_multipath_hash(rt, skb, bos);
nh_index = hash % alive;
if (alive == rt->rt_nhn)
goto out;
for_nexthops(rt) {
if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
continue;
if (n == nh_index)
return nh;
n++;
} endfor_nexthops(rt);
out:
return &rt->rt_nh[nh_index];
}
static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
struct mpls_entry_decoded dec)
{
enum mpls_payload_type payload_type;
bool success = false;
/* The IPv4 code below accesses through the IPv4 header
* checksum, which is 12 bytes into the packet.
* The IPv6 code below accesses through the IPv6 hop limit
* which is 8 bytes into the packet.
*
* For all supported cases there should always be at least 12
* bytes of packet data present. The IPv4 header is 20 bytes
* without options and the IPv6 header is always 40 bytes
* long.
*/
if (!pskb_may_pull(skb, 12))
return false;
payload_type = rt->rt_payload_type;
if (payload_type == MPT_UNSPEC)
payload_type = ip_hdr(skb)->version;
switch (payload_type) {
case MPT_IPV4: {
struct iphdr *hdr4 = ip_hdr(skb);
skb->protocol = htons(ETH_P_IP);
csum_replace2(&hdr4->check,
htons(hdr4->ttl << 8),
htons(dec.ttl << 8));
hdr4->ttl = dec.ttl;
success = true;
break;
}
case MPT_IPV6: {
struct ipv6hdr *hdr6 = ipv6_hdr(skb);
skb->protocol = htons(ETH_P_IPV6);
hdr6->hop_limit = dec.ttl;
success = true;
break;
}
case MPT_UNSPEC:
break;
}
return success;
}
static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct net *net = dev_net(dev);
struct mpls_shim_hdr *hdr;
struct mpls_route *rt;
struct mpls_nh *nh;
struct mpls_entry_decoded dec;
struct net_device *out_dev;
struct mpls_dev *mdev;
unsigned int hh_len;
unsigned int new_header_size;
unsigned int mtu;
int err;
/* Careful this entire function runs inside of an rcu critical section */
mdev = mpls_dev_get(dev);
if (!mdev || !mdev->input_enabled)
goto drop;
if (skb->pkt_type != PACKET_HOST)
goto drop;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
goto drop;
if (!pskb_may_pull(skb, sizeof(*hdr)))
goto drop;
/* Read and decode the label */
hdr = mpls_hdr(skb);
dec = mpls_entry_decode(hdr);
/* Pop the label */
skb_pull(skb, sizeof(*hdr));
skb_reset_network_header(skb);
skb_orphan(skb);
rt = mpls_route_input_rcu(net, dec.label);
if (!rt)
goto drop;
nh = mpls_select_multipath(rt, skb, dec.bos);
if (!nh)
goto drop;
/* Find the output device */
out_dev = rcu_dereference(nh->nh_dev);
if (!mpls_output_possible(out_dev))
goto drop;
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
/* Verify ttl is valid */
if (dec.ttl <= 1)
goto drop;
dec.ttl -= 1;
/* Verify the destination can hold the packet */
new_header_size = mpls_nh_header_size(nh);
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->dev = out_dev;
skb->protocol = htons(ETH_P_MPLS_UC);
if (unlikely(!new_header_size && dec.bos)) {
/* Penultimate hop popping */
if (!mpls_egress(rt, skb, dec))
goto drop;
} else {
bool bos;
int i;
skb_push(skb, new_header_size);
skb_reset_network_header(skb);
/* Push the new labels */
hdr = mpls_hdr(skb);
bos = dec.bos;
for (i = nh->nh_labels - 1; i >= 0; i--) {
hdr[i] = mpls_entry_encode(nh->nh_label[i],
dec.ttl, 0, bos);
bos = false;
}
}
err = neigh_xmit(nh->nh_via_table, out_dev, mpls_nh_via(rt, nh), skb);
if (err)
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
__func__, err);
return 0;
drop:
kfree_skb(skb);
return NET_RX_DROP;
}
static struct packet_type mpls_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.func = mpls_forward,
};
static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
[RTA_DST] = { .type = NLA_U32 },
[RTA_OIF] = { .type = NLA_U32 },
};
struct mpls_route_config {
u32 rc_protocol;
u32 rc_ifindex;
u8 rc_via_table;
u8 rc_via_alen;
u8 rc_via[MAX_VIA_ALEN];
u32 rc_label;
u8 rc_output_labels;
u32 rc_output_label[MAX_NEW_LABELS];
u32 rc_nlflags;
enum mpls_payload_type rc_payload_type;
struct nl_info rc_nlinfo;
struct rtnexthop *rc_mp;
int rc_mp_len;
};
static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen)
{
u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN);
struct mpls_route *rt;
rt = kzalloc(ALIGN(sizeof(*rt) + num_nh * sizeof(*rt->rt_nh),
VIA_ALEN_ALIGN) +
num_nh * max_alen_aligned,
GFP_KERNEL);
if (rt) {
rt->rt_nhn = num_nh;
rt->rt_nhn_alive = num_nh;
rt->rt_max_alen = max_alen_aligned;
}
return rt;
}
static void mpls_rt_free(struct mpls_route *rt)
{
if (rt)
kfree_rcu(rt, rt_rcu);
}
static void mpls_notify_route(struct net *net, unsigned index,
struct mpls_route *old, struct mpls_route *new,
const struct nl_info *info)
{
struct nlmsghdr *nlh = info ? info->nlh : NULL;
unsigned portid = info ? info->portid : 0;
int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
struct mpls_route *rt = new ? new : old;
unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
/* Ignore reserved labels for now */
if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
}
static void mpls_route_update(struct net *net, unsigned index,
struct mpls_route *new,
const struct nl_info *info)
{
struct mpls_route __rcu **platform_label;
struct mpls_route *rt;
ASSERT_RTNL();
platform_label = rtnl_dereference(net->mpls.platform_label);
rt = rtnl_dereference(platform_label[index]);
rcu_assign_pointer(platform_label[index], new);
mpls_notify_route(net, index, rt, new, info);
/* If we removed a route free it now */
mpls_rt_free(rt);
}
static unsigned find_free_label(struct net *net)
{
struct mpls_route __rcu **platform_label;
size_t platform_labels;
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
index++) {
if (!rtnl_dereference(platform_label[index]))
return index;
}
return LABEL_NOT_SPECIFIED;
}
#if IS_ENABLED(CONFIG_INET)
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct rtable *rt;
struct in_addr daddr;
memcpy(&daddr, addr, sizeof(struct in_addr));
rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
if (IS_ERR(rt))
return ERR_CAST(rt);
dev = rt->dst.dev;
dev_hold(dev);
ip_rt_put(rt);
return dev;
}
#else
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif
#if IS_ENABLED(CONFIG_IPV6)
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct dst_entry *dst;
struct flowi6 fl6;
int err;
if (!ipv6_stub)
return ERR_PTR(-EAFNOSUPPORT);
memset(&fl6, 0, sizeof(fl6));
memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
if (err)
return ERR_PTR(err);
dev = dst->dev;
dev_hold(dev);
dst_release(dst);
return dev;
}
#else
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif
static struct net_device *find_outdev(struct net *net,
struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;
if (!oif) {
switch (nh->nh_via_table) {
case NEIGH_ARP_TABLE:
dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_ND_TABLE:
dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_LINK_TABLE:
break;
}
} else {
dev = dev_get_by_index(net, oif);
}
if (!dev)
return ERR_PTR(-ENODEV);
/* The caller is holding rtnl anyways, so release the dev reference */
dev_put(dev);
return dev;
}
static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;
int err = -ENODEV;
dev = find_outdev(net, rt, nh, oif);
if (IS_ERR(dev)) {
err = PTR_ERR(dev);
dev = NULL;
goto errout;
}
/* Ensure this is a supported device */
err = -EINVAL;
if (!mpls_dev_get(dev))
goto errout;
RCU_INIT_POINTER(nh->nh_dev, dev);
if (!(dev->flags & IFF_UP)) {
nh->nh_flags |= RTNH_F_DEAD;
} else {
unsigned int flags;
flags = dev_get_flags(dev);
if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
nh->nh_flags |= RTNH_F_LINKDOWN;
}
return 0;
errout:
return err;
}
static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
struct mpls_route *rt)
{
struct net *net = cfg->rc_nlinfo.nl_net;
struct mpls_nh *nh = rt->rt_nh;
int err;
int i;
if (!nh)
return -ENOMEM;
err = -EINVAL;
/* Ensure only a supported number of labels are present */
if (cfg->rc_output_labels > MAX_NEW_LABELS)
goto errout;
nh->nh_labels = cfg->rc_output_labels;
for (i = 0; i < nh->nh_labels; i++)
nh->nh_label[i] = cfg->rc_output_label[i];
nh->nh_via_table = cfg->rc_via_table;
memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
nh->nh_via_alen = cfg->rc_via_alen;
err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
if (err)
goto errout;
if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
rt->rt_nhn_alive--;
return 0;
errout:
return err;
}
static int mpls_nh_build(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif, struct nlattr *via,
struct nlattr *newdst)
{
int err = -ENOMEM;
if (!nh)
goto errout;
if (newdst) {
err = nla_get_labels(newdst, MAX_NEW_LABELS,
&nh->nh_labels, nh->nh_label);
if (err)
goto errout;
}
err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
__mpls_nh_via(rt, nh));
if (err)
goto errout;
err = mpls_nh_assign_dev(net, rt, nh, oif);
if (err)
goto errout;
return 0;
errout:
return err;
}
static int mpls_count_nexthops(struct rtnexthop *rtnh, int len,
u8 cfg_via_alen, u8 *max_via_alen)
{
int nhs = 0;
int remaining = len;
if (!rtnh) {
*max_via_alen = cfg_via_alen;
return 1;
}
*max_via_alen = 0;
while (rtnh_ok(rtnh, remaining)) {
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
int attrlen;
attrlen = rtnh_attrlen(rtnh);
nla = nla_find(attrs, attrlen, RTA_VIA);
if (nla && nla_len(nla) >=
offsetof(struct rtvia, rtvia_addr)) {
int via_alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);
if (via_alen <= MAX_VIA_ALEN)
*max_via_alen = max_t(u16, *max_via_alen,
via_alen);
}
nhs++;
rtnh = rtnh_next(rtnh, &remaining);
}
/* leftover implies invalid nexthop configuration, discard it */
return remaining > 0 ? 0 : nhs;
}
static int mpls_nh_build_multi(struct mpls_route_config *cfg,
struct mpls_route *rt)
{
struct rtnexthop *rtnh = cfg->rc_mp;
struct nlattr *nla_via, *nla_newdst;
int remaining = cfg->rc_mp_len;
int nhs = 0;
int err = 0;
change_nexthops(rt) {
int attrlen;
nla_via = NULL;
nla_newdst = NULL;
err = -EINVAL;
if (!rtnh_ok(rtnh, remaining))
goto errout;
/* neither weighted multipath nor any flags
* are supported
*/
if (rtnh->rtnh_hops || rtnh->rtnh_flags)
goto errout;
attrlen = rtnh_attrlen(rtnh);
if (attrlen > 0) {
struct nlattr *attrs = rtnh_attrs(rtnh);
nla_via = nla_find(attrs, attrlen, RTA_VIA);
nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
}
if (!nla_via)
goto errout;
err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
rtnh->rtnh_ifindex, nla_via, nla_newdst);
if (err)
goto errout;
if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
rt->rt_nhn_alive--;
rtnh = rtnh_next(rtnh, &remaining);
nhs++;
} endfor_nexthops(rt);
rt->rt_nhn = nhs;
return 0;
errout:
return err;
}
static int mpls_route_add(struct mpls_route_config *cfg)
{
struct mpls_route __rcu **platform_label;
struct net *net = cfg->rc_nlinfo.nl_net;
struct mpls_route *rt, *old;
int err = -EINVAL;
u8 max_via_alen;
unsigned index;
int nhs;
index = cfg->rc_label;
/* If a label was not specified during insert pick one */
if ((index == LABEL_NOT_SPECIFIED) &&
(cfg->rc_nlflags & NLM_F_CREATE)) {
index = find_free_label(net);
}
/* Reserved labels may not be set */
if (index < MPLS_LABEL_FIRST_UNRESERVED)
goto errout;
/* The full 20 bit range may not be supported. */
if (index >= net->mpls.platform_labels)
goto errout;
/* Append makes no sense with mpls */
err = -EOPNOTSUPP;
if (cfg->rc_nlflags & NLM_F_APPEND)
goto errout;
err = -EEXIST;
platform_label = rtnl_dereference(net->mpls.platform_label);
old = rtnl_dereference(platform_label[index]);
if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
goto errout;
err = -EEXIST;
if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
goto errout;
err = -ENOENT;
if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
goto errout;
err = -EINVAL;
nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
cfg->rc_via_alen, &max_via_alen);
if (nhs == 0)
goto errout;
err = -ENOMEM;
rt = mpls_rt_alloc(nhs, max_via_alen);
if (!rt)
goto errout;
rt->rt_protocol = cfg->rc_protocol;
rt->rt_payload_type = cfg->rc_payload_type;
if (cfg->rc_mp)
err = mpls_nh_build_multi(cfg, rt);
else
err = mpls_nh_build_from_cfg(cfg, rt);
if (err)
goto freert;
mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
return 0;
freert:
mpls_rt_free(rt);
errout:
return err;
}
static int mpls_route_del(struct mpls_route_config *cfg)
{
struct net *net = cfg->rc_nlinfo.nl_net;
unsigned index;
int err = -EINVAL;
index = cfg->rc_label;
/* Reserved labels may not be removed */
if (index < MPLS_LABEL_FIRST_UNRESERVED)
goto errout;
/* The full 20 bit range may not be supported */
if (index >= net->mpls.platform_labels)
goto errout;
mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
err = 0;
errout:
return err;
}
#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
(&((struct mpls_dev *)0)->field)
static const struct ctl_table mpls_dev_table[] = {
{
.procname = "input",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
.data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
},
{ }
};
static int mpls_dev_sysctl_register(struct net_device *dev,
struct mpls_dev *mdev)
{
char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
struct ctl_table *table;
int i;
table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
if (!table)
goto out;
/* Table data contains only offsets relative to the base of
* the mdev at this point, so make them absolute.
*/
for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
table[i].data = (char *)mdev + (uintptr_t)table[i].data;
snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
if (!mdev->sysctl)
goto free;
return 0;
free:
kfree(table);
out:
return -ENOBUFS;
}
static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
{
struct ctl_table *table;
table = mdev->sysctl->ctl_table_arg;
unregister_net_sysctl_table(mdev->sysctl);
kfree(table);
}
static struct mpls_dev *mpls_add_dev(struct net_device *dev)
{
struct mpls_dev *mdev;
int err = -ENOMEM;
ASSERT_RTNL();
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return ERR_PTR(err);
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
goto free;
rcu_assign_pointer(dev->mpls_ptr, mdev);
return mdev;
free:
kfree(mdev);
return ERR_PTR(err);
}
static void mpls_ifdown(struct net_device *dev, int event)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
for (index = 0; index < net->mpls.platform_labels; index++) {
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
change_nexthops(rt) {
if (rtnl_dereference(nh->nh_dev) != dev)
continue;
switch (event) {
case NETDEV_DOWN:
case NETDEV_UNREGISTER:
nh->nh_flags |= RTNH_F_DEAD;
/* fall through */
case NETDEV_CHANGE:
nh->nh_flags |= RTNH_F_LINKDOWN;
ACCESS_ONCE(rt->rt_nhn_alive) = rt->rt_nhn_alive - 1;
break;
}
if (event == NETDEV_UNREGISTER)
RCU_INIT_POINTER(nh->nh_dev, NULL);
} endfor_nexthops(rt);
}
return;
}
static void mpls_ifup(struct net_device *dev, unsigned int nh_flags)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
unsigned index;
int alive;
platform_label = rtnl_dereference(net->mpls.platform_label);
for (index = 0; index < net->mpls.platform_labels; index++) {
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
alive = 0;
change_nexthops(rt) {
struct net_device *nh_dev =
rtnl_dereference(nh->nh_dev);
if (!(nh->nh_flags & nh_flags)) {
alive++;
continue;
}
if (nh_dev != dev)
continue;
alive++;
nh->nh_flags &= ~nh_flags;
} endfor_nexthops(rt);
ACCESS_ONCE(rt->rt_nhn_alive) = alive;
}
return;
}
static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct mpls_dev *mdev;
unsigned int flags;
if (event == NETDEV_REGISTER) {
/* For now just support ethernet devices */
if ((dev->type == ARPHRD_ETHER) ||
(dev->type == ARPHRD_LOOPBACK)) {
mdev = mpls_add_dev(dev);
if (IS_ERR(mdev))
return notifier_from_errno(PTR_ERR(mdev));
}
return NOTIFY_OK;
}
mdev = mpls_dev_get(dev);
if (!mdev)
return NOTIFY_OK;
switch (event) {
case NETDEV_DOWN:
mpls_ifdown(dev, event);
break;
case NETDEV_UP:
flags = dev_get_flags(dev);
if (flags & (IFF_RUNNING | IFF_LOWER_UP))
mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
else
mpls_ifup(dev, RTNH_F_DEAD);
break;
case NETDEV_CHANGE:
flags = dev_get_flags(dev);
if (flags & (IFF_RUNNING | IFF_LOWER_UP))
mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
else
mpls_ifdown(dev, event);
break;
case NETDEV_UNREGISTER:
mpls_ifdown(dev, event);
mdev = mpls_dev_get(dev);
if (mdev) {
mpls_dev_sysctl_unregister(mdev);
RCU_INIT_POINTER(dev->mpls_ptr, NULL);
kfree_rcu(mdev, rcu);
}
break;
case NETDEV_CHANGENAME:
mdev = mpls_dev_get(dev);
if (mdev) {
int err;
mpls_dev_sysctl_unregister(mdev);
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
return notifier_from_errno(err);
}
break;
}
return NOTIFY_OK;
}
static struct notifier_block mpls_dev_notifier = {
.notifier_call = mpls_dev_notify,
};
static int nla_put_via(struct sk_buff *skb,
u8 table, const void *addr, int alen)
{
static const int table_to_family[NEIGH_NR_TABLES + 1] = {
AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
};
struct nlattr *nla;
struct rtvia *via;
int family = AF_UNSPEC;
nla = nla_reserve(skb, RTA_VIA, alen + 2);
if (!nla)
return -EMSGSIZE;
if (table <= NEIGH_NR_TABLES)
family = table_to_family[table];
via = nla_data(nla);
via->rtvia_family = family;
memcpy(via->rtvia_addr, addr, alen);
return 0;
}
int nla_put_labels(struct sk_buff *skb, int attrtype,
u8 labels, const u32 label[])
{
struct nlattr *nla;
struct mpls_shim_hdr *nla_label;
bool bos;
int i;
nla = nla_reserve(skb, attrtype, labels*4);
if (!nla)
return -EMSGSIZE;
nla_label = nla_data(nla);
bos = true;
for (i = labels - 1; i >= 0; i--) {
nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
bos = false;
}
return 0;
}
EXPORT_SYMBOL_GPL(nla_put_labels);
int nla_get_labels(const struct nlattr *nla,
u32 max_labels, u8 *labels, u32 label[])
{
unsigned len = nla_len(nla);
unsigned nla_labels;
struct mpls_shim_hdr *nla_label;
bool bos;
int i;
/* len needs to be an even multiple of 4 (the label size) */
if (len & 3)
return -EINVAL;
/* Limit the number of new labels allowed */
nla_labels = len/4;
if (nla_labels > max_labels)
return -EINVAL;
nla_label = nla_data(nla);
bos = true;
for (i = nla_labels - 1; i >= 0; i--, bos = false) {
struct mpls_entry_decoded dec;
dec = mpls_entry_decode(nla_label + i);
/* Ensure the bottom of stack flag is properly set
* and ttl and tc are both clear.
*/
if ((dec.bos != bos) || dec.ttl || dec.tc)
return -EINVAL;
switch (dec.label) {
case MPLS_LABEL_IMPLNULL:
/* RFC3032: This is a label that an LSR may
* assign and distribute, but which never
* actually appears in the encapsulation.
*/
return -EINVAL;
}
label[i] = dec.label;
}
*labels = nla_labels;
return 0;
}
EXPORT_SYMBOL_GPL(nla_get_labels);
int nla_get_via(const struct nlattr *nla, u8 *via_alen,
u8 *via_table, u8 via_addr[])
{
struct rtvia *via = nla_data(nla);
int err = -EINVAL;
int alen;
if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
goto errout;
alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);
if (alen > MAX_VIA_ALEN)
goto errout;
/* Validate the address family */
switch (via->rtvia_family) {
case AF_PACKET:
*via_table = NEIGH_LINK_TABLE;
break;
case AF_INET:
*via_table = NEIGH_ARP_TABLE;
if (alen != 4)
goto errout;
break;
case AF_INET6:
*via_table = NEIGH_ND_TABLE;
if (alen != 16)
goto errout;
break;
default:
/* Unsupported address family */
goto errout;
}
memcpy(via_addr, via->rtvia_addr, alen);
*via_alen = alen;
err = 0;
errout:
return err;
}
static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
struct mpls_route_config *cfg)
{
struct rtmsg *rtm;
struct nlattr *tb[RTA_MAX+1];
int index;
int err;
err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
if (err < 0)
goto errout;
err = -EINVAL;
rtm = nlmsg_data(nlh);
memset(cfg, 0, sizeof(*cfg));
if (rtm->rtm_family != AF_MPLS)
goto errout;
if (rtm->rtm_dst_len != 20)
goto errout;
if (rtm->rtm_src_len != 0)
goto errout;
if (rtm->rtm_tos != 0)
goto errout;
if (rtm->rtm_table != RT_TABLE_MAIN)
goto errout;
/* Any value is acceptable for rtm_protocol */
/* As mpls uses destination specific addresses
* (or source specific address in the case of multicast)
* all addresses have universal scope.
*/
if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
goto errout;
if (rtm->rtm_type != RTN_UNICAST)
goto errout;
if (rtm->rtm_flags != 0)
goto errout;
cfg->rc_label = LABEL_NOT_SPECIFIED;
cfg->rc_protocol = rtm->rtm_protocol;
cfg->rc_nlflags = nlh->nlmsg_flags;
cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
cfg->rc_nlinfo.nlh = nlh;
cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
for (index = 0; index <= RTA_MAX; index++) {
struct nlattr *nla = tb[index];
if (!nla)
continue;
switch(index) {
case RTA_OIF:
cfg->rc_ifindex = nla_get_u32(nla);
break;
case RTA_NEWDST:
if (nla_get_labels(nla, MAX_NEW_LABELS,
&cfg->rc_output_labels,
cfg->rc_output_label))
goto errout;
break;
case RTA_DST:
{
u8 label_count;
if (nla_get_labels(nla, 1, &label_count,
&cfg->rc_label))
goto errout;
/* Reserved labels may not be set */
if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED)
goto errout;
break;
}
case RTA_VIA:
{
if (nla_get_via(nla, &cfg->rc_via_alen,
&cfg->rc_via_table, cfg->rc_via))
goto errout;
break;
}
case RTA_MULTIPATH:
{
cfg->rc_mp = nla_data(nla);
cfg->rc_mp_len = nla_len(nla);
break;
}
default:
/* Unsupported attribute */
goto errout;
}
}
err = 0;
errout:
return err;
}
static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct mpls_route_config cfg;
int err;
err = rtm_to_route_config(skb, nlh, &cfg);
if (err < 0)
return err;
return mpls_route_del(&cfg);
}
static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct mpls_route_config cfg;
int err;
err = rtm_to_route_config(skb, nlh, &cfg);
if (err < 0)
return err;
return mpls_route_add(&cfg);
}
static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
u32 label, struct mpls_route *rt, int flags)
{
struct net_device *dev;
struct nlmsghdr *nlh;
struct rtmsg *rtm;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
if (nlh == NULL)
return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = AF_MPLS;
rtm->rtm_dst_len = 20;
rtm->rtm_src_len = 0;
rtm->rtm_tos = 0;
rtm->rtm_table = RT_TABLE_MAIN;
rtm->rtm_protocol = rt->rt_protocol;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_type = RTN_UNICAST;
rtm->rtm_flags = 0;
if (nla_put_labels(skb, RTA_DST, 1, &label))
goto nla_put_failure;
if (rt->rt_nhn == 1) {
const struct mpls_nh *nh = rt->rt_nh;
if (nh->nh_labels &&
nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
if (nh->nh_flags & RTNH_F_LINKDOWN)
rtm->rtm_flags |= RTNH_F_LINKDOWN;
if (nh->nh_flags & RTNH_F_DEAD)
rtm->rtm_flags |= RTNH_F_DEAD;
} else {
struct rtnexthop *rtnh;
struct nlattr *mp;
int dead = 0;
int linkdown = 0;
mp = nla_nest_start(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;
for_nexthops(rt) {
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
if (!rtnh)
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
if (dev)
rtnh->rtnh_ifindex = dev->ifindex;
if (nh->nh_flags & RTNH_F_LINKDOWN) {
rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
linkdown++;
}
if (nh->nh_flags & RTNH_F_DEAD) {
rtnh->rtnh_flags |= RTNH_F_DEAD;
dead++;
}
if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nla_put_via(skb, nh->nh_via_table,
mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
/* length of rtnetlink header + attributes */
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
} endfor_nexthops(rt);
if (linkdown == rt->rt_nhn)
rtm->rtm_flags |= RTNH_F_LINKDOWN;
if (dead == rt->rt_nhn)
rtm->rtm_flags |= RTNH_F_DEAD;
nla_nest_end(skb, mp);
}
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct mpls_route __rcu **platform_label;
size_t platform_labels;
unsigned int index;
ASSERT_RTNL();
index = cb->args[0];
if (index < MPLS_LABEL_FIRST_UNRESERVED)
index = MPLS_LABEL_FIRST_UNRESERVED;
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (; index < platform_labels; index++) {
struct mpls_route *rt;
rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, RTM_NEWROUTE,
index, rt, NLM_F_MULTI) < 0)
break;
}
cb->args[0] = index;
return skb->len;
}
static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
{
size_t payload =
NLMSG_ALIGN(sizeof(struct rtmsg))
+ nla_total_size(4); /* RTA_DST */
if (rt->rt_nhn == 1) {
struct mpls_nh *nh = rt->rt_nh;
if (nh->nh_dev)
payload += nla_total_size(4); /* RTA_OIF */
payload += nla_total_size(2 + nh->nh_via_alen); /* RTA_VIA */
if (nh->nh_labels) /* RTA_NEWDST */
payload += nla_total_size(nh->nh_labels * 4);
} else {
/* each nexthop is packed in an attribute */
size_t nhsize = 0;
for_nexthops(rt) {
nhsize += nla_total_size(sizeof(struct rtnexthop));
nhsize += nla_total_size(2 + nh->nh_via_alen);
if (nh->nh_labels)
nhsize += nla_total_size(nh->nh_labels * 4);
} endfor_nexthops(rt);
/* nested attribute */
payload += nla_total_size(nhsize);
}
return payload;
}
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
struct nlmsghdr *nlh, struct net *net, u32 portid,
unsigned int nlm_flags)
{
struct sk_buff *skb;
u32 seq = nlh ? nlh->nlmsg_seq : 0;
int err = -ENOBUFS;
skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
if (skb == NULL)
goto errout;
err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
if (err < 0) {
/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
return;
errout:
if (err < 0)
rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
}
static int resize_platform_label_table(struct net *net, size_t limit)
{
size_t size = sizeof(struct mpls_route *) * limit;
size_t old_limit;
size_t cp_size;
struct mpls_route __rcu **labels = NULL, **old;
struct mpls_route *rt0 = NULL, *rt2 = NULL;
unsigned index;
if (size) {
labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
if (!labels)
labels = vzalloc(size);
if (!labels)
goto nolabels;
}
/* In case the predefined labels need to be populated */
if (limit > MPLS_LABEL_IPV4NULL) {
struct net_device *lo = net->loopback_dev;
rt0 = mpls_rt_alloc(1, lo->addr_len);
if (!rt0)
goto nort0;
RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
rt0->rt_protocol = RTPROT_KERNEL;
rt0->rt_payload_type = MPT_IPV4;
rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
rt0->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
lo->addr_len);
}
if (limit > MPLS_LABEL_IPV6NULL) {
struct net_device *lo = net->loopback_dev;
rt2 = mpls_rt_alloc(1, lo->addr_len);
if (!rt2)
goto nort2;
RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
rt2->rt_protocol = RTPROT_KERNEL;
rt2->rt_payload_type = MPT_IPV6;
rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
rt2->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
lo->addr_len);
}
rtnl_lock();
/* Remember the original table */
old = rtnl_dereference(net->mpls.platform_label);
old_limit = net->mpls.platform_labels;
/* Free any labels beyond the new table */
for (index = limit; index < old_limit; index++)
mpls_route_update(net, index, NULL, NULL);
/* Copy over the old labels */
cp_size = size;
if (old_limit < limit)
cp_size = old_limit * sizeof(struct mpls_route *);
memcpy(labels, old, cp_size);
/* If needed set the predefined labels */
if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
(limit > MPLS_LABEL_IPV6NULL)) {
RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
rt2 = NULL;
}
if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
(limit > MPLS_LABEL_IPV4NULL)) {
RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
rt0 = NULL;
}
/* Update the global pointers */
net->mpls.platform_labels = limit;
rcu_assign_pointer(net->mpls.platform_label, labels);
rtnl_unlock();
mpls_rt_free(rt2);
mpls_rt_free(rt0);
if (old) {
synchronize_rcu();
kvfree(old);
}
return 0;
nort2:
mpls_rt_free(rt0);
nort0:
kvfree(labels);
nolabels:
return -ENOMEM;
}
static int mpls_platform_labels(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = table->data;
int platform_labels = net->mpls.platform_labels;
int ret;
struct ctl_table tmp = {
.procname = table->procname,
.data = &platform_labels,
.maxlen = sizeof(int),
.mode = table->mode,
.extra1 = &zero,
.extra2 = &label_limit,
};
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && ret == 0)
ret = resize_platform_label_table(net, platform_labels);
return ret;
}
static const struct ctl_table mpls_table[] = {
{
.procname = "platform_labels",
.data = NULL,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = mpls_platform_labels,
},
{ }
};
static int mpls_net_init(struct net *net)
{
struct ctl_table *table;
net->mpls.platform_labels = 0;
net->mpls.platform_label = NULL;
table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
if (table == NULL)
return -ENOMEM;
table[0].data = net;
net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
if (net->mpls.ctl == NULL) {
kfree(table);
return -ENOMEM;
}
return 0;
}
static void mpls_net_exit(struct net *net)
{
struct mpls_route __rcu **platform_label;
size_t platform_labels;
struct ctl_table *table;
unsigned int index;
table = net->mpls.ctl->ctl_table_arg;
unregister_net_sysctl_table(net->mpls.ctl);
kfree(table);
/* An rcu grace period has passed since there was a device in
* the network namespace (and thus the last in flight packet)
* left this network namespace. This is because
* unregister_netdevice_many and netdev_run_todo has completed
* for each network device that was in this network namespace.
*
* As such no additional rcu synchronization is necessary when
* freeing the platform_label table.
*/
rtnl_lock();
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (index = 0; index < platform_labels; index++) {
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
RCU_INIT_POINTER(platform_label[index], NULL);
mpls_rt_free(rt);
}
rtnl_unlock();
kvfree(platform_label);
}
static struct pernet_operations mpls_net_ops = {
.init = mpls_net_init,
.exit = mpls_net_exit,
};
static int __init mpls_init(void)
{
int err;
BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
err = register_pernet_subsys(&mpls_net_ops);
if (err)
goto out;
err = register_netdevice_notifier(&mpls_dev_notifier);
if (err)
goto out_unregister_pernet;
dev_add_pack(&mpls_packet_type);
rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL);
rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL);
rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL);
err = 0;
out:
return err;
out_unregister_pernet:
unregister_pernet_subsys(&mpls_net_ops);
goto out;
}
module_init(mpls_init);
static void __exit mpls_exit(void)
{
rtnl_unregister_all(PF_MPLS);
dev_remove_pack(&mpls_packet_type);
unregister_netdevice_notifier(&mpls_dev_notifier);
unregister_pernet_subsys(&mpls_net_ops);
}
module_exit(mpls_exit);
MODULE_DESCRIPTION("MultiProtocol Label Switching");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_NETPROTO(PF_MPLS);