Merge branch 'for-davem' into for-next

4 files changed, 1106 insertions, 0 deletions

diff --git a/net/mpls/Kconfig b/net/mpls/Kconfig
index 37421db88965..17bde799c854 100644
--- a/net/mpls/Kconfig
+++ b/net/mpls/Kconfig
@@ -1,9 +1,30 @@
 #
 # MPLS configuration
 #
+
+menuconfig MPLS
+	bool "MultiProtocol Label Switching"
+	default n
+	---help---
+	  MultiProtocol Label Switching routes packets through logical
+	  circuits.  Originally conceived as a way of routing packets at
+	  hardware speeds (before hardware was capable of routing ipv4 packets),
+	  MPLS remains a simple way of making tunnels.
+
+	  If you have not heard of MPLS you probably want to say N here.
+
+if MPLS
+
 config NET_MPLS_GSO
 	tristate "MPLS: GSO support"
 	help
 	 This is helper module to allow segmentation of non-MPLS GSO packets
 	 that have had MPLS stack entries pushed onto them and thus
 	 become MPLS GSO packets.
+
+config MPLS_ROUTING
+	tristate "MPLS: routing support"
+	help
+	 Add support for forwarding of mpls packets.
+
+endif # MPLS
diff --git a/net/mpls/Makefile b/net/mpls/Makefile
index 6dec088c2d0f..65bbe68c72e6 100644
--- a/net/mpls/Makefile
+++ b/net/mpls/Makefile
@@ -2,3 +2,6 @@
 # Makefile for MPLS.
 #
 obj-$(CONFIG_NET_MPLS_GSO) += mpls_gso.o
+obj-$(CONFIG_MPLS_ROUTING) += mpls_router.o
+
+mpls_router-y := af_mpls.o
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
new file mode 100644
index 000000000000..db8a2ea6d4de
--- /dev/null
+++ b/net/mpls/af_mpls.c
@@ -0,0 +1,1023 @@
+#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>
+#include "internal.h"
+
+#define LABEL_NOT_SPECIFIED (1<<20)
+#define MAX_NEW_LABELS 2
+
+/* This maximum ha length copied from the definition of struct neighbour */
+#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
+
+struct mpls_route { /* next hop label forwarding entry */
+	struct net_device __rcu *rt_dev;
+	struct rcu_head		rt_rcu;
+	u32			rt_label[MAX_NEW_LABELS];
+	u8			rt_protocol; /* routing protocol that set this entry */
+	u8			rt_labels;
+	u8			rt_via_alen;
+	u8			rt_via_table;
+	u8			rt_via[0];
+};
+
+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 bool mpls_output_possible(const struct net_device *dev)
+{
+	return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
+}
+
+static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
+{
+	/* The size of the layer 2.5 labels to be added for this route */
+	return rt->rt_labels * sizeof(struct mpls_shim_hdr);
+}
+
+static unsigned int mpls_dev_mtu(const struct net_device *dev)
+{
+	/* The amount of data the layer 2 frame can hold */
+	return dev->mtu;
+}
+
+static 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;
+}
+
+static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
+			struct mpls_entry_decoded dec)
+{
+	/* RFC4385 and RFC5586 encode other packets in mpls such that
+	 * they don't conflict with the ip version number, making
+	 * decoding by examining the ip version correct in everything
+	 * except for the strangest cases.
+	 *
+	 * The strange cases if we choose to support them will require
+	 * manual configuration.
+	 */
+	struct iphdr *hdr4;
+	bool success = true;
+
+	/* 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;
+
+	/* Use ip_hdr to find the ip protocol version */
+	hdr4 = ip_hdr(skb);
+	if (hdr4->version == 4) {
+		skb->protocol = htons(ETH_P_IP);
+		csum_replace2(&hdr4->check,
+			      htons(hdr4->ttl << 8),
+			      htons(dec.ttl << 8));
+		hdr4->ttl = dec.ttl;
+	}
+	else if (hdr4->version == 6) {
+		struct ipv6hdr *hdr6 = ipv6_hdr(skb);
+		skb->protocol = htons(ETH_P_IPV6);
+		hdr6->hop_limit = dec.ttl;
+	}
+	else
+		/* version 0 and version 1 are used by pseudo wires */
+		success = false;
+	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_entry_decoded dec;
+	struct net_device *out_dev;
+	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 */
+
+	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;
+
+	/* Find the output device */
+	out_dev = rcu_dereference(rt->rt_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_rt_header_size(rt);
+	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 = rt->rt_labels - 1; i >= 0; i--) {
+			hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
+			bos = false;
+		}
+	}
+
+	err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, 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;
+	u16		rc_via_table;
+	u16		rc_via_alen;
+	u8		rc_via[MAX_VIA_ALEN];
+	u32		rc_label;
+	u32		rc_output_labels;
+	u32		rc_output_label[MAX_NEW_LABELS];
+	u32		rc_nlflags;
+	struct nl_info	rc_nlinfo;
+};
+
+static struct mpls_route *mpls_rt_alloc(size_t alen)
+{
+	struct mpls_route *rt;
+
+	rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
+	if (rt)
+		rt->rt_via_alen = alen;
+	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 >= 16))
+		rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
+}
+
+static void mpls_route_update(struct net *net, unsigned index,
+			      struct net_device *dev, struct mpls_route *new,
+			      const struct nl_info *info)
+{
+	struct mpls_route __rcu **platform_label;
+	struct mpls_route *rt, *old = NULL;
+
+	ASSERT_RTNL();
+
+	platform_label = rtnl_dereference(net->mpls.platform_label);
+	rt = rtnl_dereference(platform_label[index]);
+	if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
+		rcu_assign_pointer(platform_label[index], new);
+		old = rt;
+	}
+
+	mpls_notify_route(net, index, old, new, info);
+
+	/* If we removed a route free it now */
+	mpls_rt_free(old);
+}
+
+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 = 16; index < platform_labels; index++) {
+		if (!rtnl_dereference(platform_label[index]))
+			return index;
+	}
+	return LABEL_NOT_SPECIFIED;
+}
+
+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 net_device *dev = NULL;
+	struct mpls_route *rt, *old;
+	unsigned index;
+	int i;
+	int err = -EINVAL;
+
+	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);
+	}
+
+	/* The first 16 labels are reserved, and may not be set */
+	if (index < 16)
+		goto errout;
+
+	/* The full 20 bit range may not be supported. */
+	if (index >= net->mpls.platform_labels)
+		goto errout;
+
+	/* Ensure only a supported number of labels are present */
+	if (cfg->rc_output_labels > MAX_NEW_LABELS)
+		goto errout;
+
+	err = -ENODEV;
+	dev = dev_get_by_index(net, cfg->rc_ifindex);
+	if (!dev)
+		goto errout;
+
+	/* For now just support ethernet devices */
+	err = -EINVAL;
+	if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
+		goto errout;
+
+	err = -EINVAL;
+	if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
+	    (dev->addr_len != cfg->rc_via_alen))
+		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 = -ENOMEM;
+	rt = mpls_rt_alloc(cfg->rc_via_alen);
+	if (!rt)
+		goto errout;
+
+	rt->rt_labels = cfg->rc_output_labels;
+	for (i = 0; i < rt->rt_labels; i++)
+		rt->rt_label[i] = cfg->rc_output_label[i];
+	rt->rt_protocol = cfg->rc_protocol;
+	RCU_INIT_POINTER(rt->rt_dev, dev);
+	rt->rt_via_table = cfg->rc_via_table;
+	memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
+
+	mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
+
+	dev_put(dev);
+	return 0;
+
+errout:
+	if (dev)
+		dev_put(dev);
+	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;
+
+	/* The first 16 labels are reserved, and may not be removed */
+	if (index < 16)
+		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, NULL, &cfg->rc_nlinfo);
+
+	err = 0;
+errout:
+	return err;
+}
+
+static void mpls_ifdown(struct net_device *dev)
+{
+	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;
+		if (rtnl_dereference(rt->rt_dev) != dev)
+			continue;
+		rt->rt_dev = NULL;
+	}
+}
+
+static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
+			   void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	switch(event) {
+	case NETDEV_UNREGISTER:
+		mpls_ifdown(dev);
+		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;
+}
+
+int nla_get_labels(const struct nlattr *nla,
+		   u32 max_labels, u32 *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;
+
+		label[i] = dec.label;
+	}
+	*labels = nla_labels;
+	return 0;
+}
+
+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:
+		{
+			u32 label_count;
+			if (nla_get_labels(nla, 1, &label_count,
+					   &cfg->rc_label))
+				goto errout;
+
+			/* The first 16 labels are reserved, and may not be set */
+			if (cfg->rc_label < 16)
+				goto errout;
+
+			break;
+		}
+		case RTA_VIA:
+		{
+			struct rtvia *via = nla_data(nla);
+			if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
+				goto errout;
+			cfg->rc_via_alen   = nla_len(nla) -
+				offsetof(struct rtvia, rtvia_addr);
+			if (cfg->rc_via_alen > MAX_VIA_ALEN)
+				goto errout;
+
+			/* Validate the address family */
+			switch(via->rtvia_family) {
+			case AF_PACKET:
+				cfg->rc_via_table = NEIGH_LINK_TABLE;
+				break;
+			case AF_INET:
+				cfg->rc_via_table = NEIGH_ARP_TABLE;
+				if (cfg->rc_via_alen != 4)
+					goto errout;
+				break;
+			case AF_INET6:
+				cfg->rc_via_table = NEIGH_ND_TABLE;
+				if (cfg->rc_via_alen != 16)
+					goto errout;
+				break;
+			default:
+				/* Unsupported address family */
+				goto errout;
+			}
+
+			memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
+			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 (rt->rt_labels &&
+	    nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
+		goto nla_put_failure;
+	if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
+		goto nla_put_failure;
+	dev = rtnl_dereference(rt->rt_dev);
+	if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
+		goto nla_put_failure;
+	if (nla_put_labels(skb, RTA_DST, 1, &label))
+		goto nla_put_failure;
+
+	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 < 16)
+		index = 16;
+
+	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(2 + rt->rt_via_alen)	/* RTA_VIA */
+		+ nla_total_size(4);			/* RTA_DST */
+	if (rt->rt_labels)				/* RTA_NEWDST */
+		payload += nla_total_size(rt->rt_labels * 4);
+	if (rt->rt_dev)					/* RTA_OIF */
+		payload += nla_total_size(4);
+	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 > LABEL_IPV4_EXPLICIT_NULL) {
+		struct net_device *lo = net->loopback_dev;
+		rt0 = mpls_rt_alloc(lo->addr_len);
+		if (!rt0)
+			goto nort0;
+		RCU_INIT_POINTER(rt0->rt_dev, lo);
+		rt0->rt_protocol = RTPROT_KERNEL;
+		rt0->rt_via_table = NEIGH_LINK_TABLE;
+		memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
+	}
+	if (limit > LABEL_IPV6_EXPLICIT_NULL) {
+		struct net_device *lo = net->loopback_dev;
+		rt2 = mpls_rt_alloc(lo->addr_len);
+		if (!rt2)
+			goto nort2;
+		RCU_INIT_POINTER(rt2->rt_dev, lo);
+		rt2->rt_protocol = RTPROT_KERNEL;
+		rt2->rt_via_table = NEIGH_LINK_TABLE;
+		memcpy(rt2->rt_via, 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, 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 <= LABEL_IPV6_EXPLICIT_NULL) &&
+	    (limit > LABEL_IPV6_EXPLICIT_NULL)) {
+		RCU_INIT_POINTER(labels[LABEL_IPV6_EXPLICIT_NULL], rt2);
+		rt2 = NULL;
+	}
+
+	if ((old_limit <= LABEL_IPV4_EXPLICIT_NULL) &&
+	    (limit > LABEL_IPV4_EXPLICIT_NULL)) {
+		RCU_INIT_POINTER(labels[LABEL_IPV4_EXPLICIT_NULL], 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 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)
+		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);
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
new file mode 100644
index 000000000000..fb6de92052c4
--- /dev/null
+++ b/net/mpls/internal.h
@@ -0,0 +1,59 @@
+#ifndef MPLS_INTERNAL_H
+#define MPLS_INTERNAL_H
+
+#define LABEL_IPV4_EXPLICIT_NULL	0 /* RFC3032 */
+#define LABEL_ROUTER_ALERT_LABEL	1 /* RFC3032 */
+#define LABEL_IPV6_EXPLICIT_NULL	2 /* RFC3032 */
+#define LABEL_IMPLICIT_NULL		3 /* RFC3032 */
+#define LABEL_ENTROPY_INDICATOR		7 /* RFC6790 */
+#define LABEL_GAL			13 /* RFC5586 */
+#define LABEL_OAM_ALERT			14 /* RFC3429 */
+#define LABEL_EXTENSION			15 /* RFC7274 */
+
+
+struct mpls_shim_hdr {
+	__be32 label_stack_entry;
+};
+
+struct mpls_entry_decoded {
+	u32 label;
+	u8 ttl;
+	u8 tc;
+	u8 bos;
+};
+
+struct sk_buff;
+
+static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
+{
+	return (struct mpls_shim_hdr *)skb_network_header(skb);
+}
+
+static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
+{
+	struct mpls_shim_hdr result;
+	result.label_stack_entry =
+		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
+			    (tc << MPLS_LS_TC_SHIFT) |
+			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
+			    (ttl << MPLS_LS_TTL_SHIFT));
+	return result;
+}
+
+static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
+{
+	struct mpls_entry_decoded result;
+	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
+
+	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
+	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
+	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
+	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
+
+	return result;
+}
+
+int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels, const u32 label[]);
+int nla_get_labels(const struct nlattr *nla, u32 max_labels, u32 *labels, u32 label[]);
+
+#endif /* MPLS_INTERNAL_H */