Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2799 insertions, 0 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
new file mode 100644
index 000000000..f1f43894e
--- /dev/null
+++ b/net/mpls/af_mpls.c
@@ -0,0 +1,2799 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#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/netconf.h>
+#include <linux/nospec.h>
+#include <linux/vmalloc.h>
+#include <linux/percpu.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/ip_tunnels.h>
+#include <net/netns/generic.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#endif
+#include <net/ipv6_stubs.h>
+#include <net/rtnh.h>
+#include "internal.h"
+
+/* max memory we will use for mpls_route */
+#define MAX_MPLS_ROUTE_MEM	4096
+
+/* Maximum number of labels to look ahead at when selecting a path of
+ * a multipath route
+ */
+#define MAX_MP_SELECT_LABELS 4
+
+#define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
+
+static int label_limit = (1 << 20) - 1;
+static int ttl_max = 255;
+
+#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
+static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
+{
+	return sizeof(struct mpls_shim_hdr);
+}
+
+static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
+	.encap_hlen	= ipgre_mpls_encap_hlen,
+};
+
+static int ipgre_tunnel_encap_add_mpls_ops(void)
+{
+	return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+}
+
+static void ipgre_tunnel_encap_del_mpls_ops(void)
+{
+	ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
+}
+#else
+static int ipgre_tunnel_encap_add_mpls_ops(void)
+{
+	return 0;
+}
+
+static void ipgre_tunnel_encap_del_mpls_ops(void)
+{
+}
+#endif
+
+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;
+}
+
+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)
+{
+	return (u8 *)nh + rt->rt_via_offset;
+}
+
+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_validate_network_len(skb, mtu))
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
+
+void mpls_stats_inc_outucastpkts(struct net_device *dev,
+				 const struct sk_buff *skb)
+{
+	struct mpls_dev *mdev;
+
+	if (skb->protocol == htons(ETH_P_MPLS_UC)) {
+		mdev = mpls_dev_get(dev);
+		if (mdev)
+			MPLS_INC_STATS_LEN(mdev, skb->len,
+					   tx_packets,
+					   tx_bytes);
+	} else if (skb->protocol == htons(ETH_P_IP)) {
+		IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		struct inet6_dev *in6dev = __in6_dev_get(dev);
+
+		if (in6dev)
+			IP6_UPD_PO_STATS(dev_net(dev), in6dev,
+					 IPSTATS_MIB_OUT, skb->len);
+#endif
+	}
+}
+EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
+
+static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
+{
+	struct mpls_entry_decoded dec;
+	unsigned int mpls_hdr_len = 0;
+	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;
+	     label_index++) {
+		mpls_hdr_len += sizeof(*hdr);
+		if (!pskb_may_pull(skb, mpls_hdr_len))
+			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;
+		}
+
+		if (!dec.bos)
+			continue;
+
+		/* found bottom label; does skb have room for a header? */
+		if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
+			const struct iphdr *v4hdr;
+
+			v4hdr = (const struct iphdr *)(hdr + 1);
+			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, mpls_hdr_len +
+						 sizeof(struct ipv6hdr))) {
+				const struct ipv6hdr *v6hdr;
+
+				v6hdr = (const struct ipv6hdr *)(hdr + 1);
+				hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
+				hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
+				hash = jhash_1word(v6hdr->nexthdr, hash);
+			}
+		}
+
+		break;
+	}
+
+	return hash;
+}
+
+static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
+{
+	return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
+}
+
+/* number of alive nexthops (rt->rt_nhn_alive) and the flags for
+ * a next hop (nh->nh_flags) are modified by netdev event handlers.
+ * Since those fields can change at any moment, use READ_ONCE to
+ * access both.
+ */
+static const struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
+						   struct sk_buff *skb)
+{
+	u32 hash = 0;
+	int nh_index = 0;
+	int n = 0;
+	u8 alive;
+
+	/* No need to look further into packet if there's only
+	 * one path
+	 */
+	if (rt->rt_nhn == 1)
+		return rt->rt_nh;
+
+	alive = READ_ONCE(rt->rt_nhn_alive);
+	if (alive == 0)
+		return NULL;
+
+	hash = mpls_multipath_hash(rt, skb);
+	nh_index = hash % alive;
+	if (alive == rt->rt_nhn)
+		goto out;
+	for_nexthops(rt) {
+		unsigned int nh_flags = READ_ONCE(nh->nh_flags);
+
+		if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
+			continue;
+		if (n == nh_index)
+			return nh;
+		n++;
+	} endfor_nexthops(rt);
+
+out:
+	return mpls_get_nexthop(rt, nh_index);
+}
+
+static bool mpls_egress(struct net *net, 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);
+		u8 new_ttl;
+		skb->protocol = htons(ETH_P_IP);
+
+		/* If propagating TTL, take the decremented TTL from
+		 * the incoming MPLS header, otherwise decrement the
+		 * TTL, but only if not 0 to avoid underflow.
+		 */
+		if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
+		    (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
+		     net->mpls.ip_ttl_propagate))
+			new_ttl = dec.ttl;
+		else
+			new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
+
+		csum_replace2(&hdr4->check,
+			      htons(hdr4->ttl << 8),
+			      htons(new_ttl << 8));
+		hdr4->ttl = new_ttl;
+		success = true;
+		break;
+	}
+	case MPT_IPV6: {
+		struct ipv6hdr *hdr6 = ipv6_hdr(skb);
+		skb->protocol = htons(ETH_P_IPV6);
+
+		/* If propagating TTL, take the decremented TTL from
+		 * the incoming MPLS header, otherwise decrement the
+		 * hop limit, but only if not 0 to avoid underflow.
+		 */
+		if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
+		    (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
+		     net->mpls.ip_ttl_propagate))
+			hdr6->hop_limit = dec.ttl;
+		else if (hdr6->hop_limit)
+			hdr6->hop_limit = hdr6->hop_limit - 1;
+		success = true;
+		break;
+	}
+	case MPT_UNSPEC:
+		/* Should have decided which protocol it is by now */
+		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;
+	const struct mpls_nh *nh;
+	struct mpls_route *rt;
+	struct mpls_entry_decoded dec;
+	struct net_device *out_dev;
+	struct mpls_dev *out_mdev;
+	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)
+		goto drop;
+
+	MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
+			   rx_bytes);
+
+	if (!mdev->input_enabled) {
+		MPLS_INC_STATS(mdev, rx_dropped);
+		goto drop;
+	}
+
+	if (skb->pkt_type != PACKET_HOST)
+		goto err;
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+		goto err;
+
+	if (!pskb_may_pull(skb, sizeof(*hdr)))
+		goto err;
+
+	skb_dst_drop(skb);
+
+	/* Read and decode the label */
+	hdr = mpls_hdr(skb);
+	dec = mpls_entry_decode(hdr);
+
+	rt = mpls_route_input_rcu(net, dec.label);
+	if (!rt) {
+		MPLS_INC_STATS(mdev, rx_noroute);
+		goto drop;
+	}
+
+	nh = mpls_select_multipath(rt, skb);
+	if (!nh)
+		goto err;
+
+	/* Pop the label */
+	skb_pull(skb, sizeof(*hdr));
+	skb_reset_network_header(skb);
+
+	skb_orphan(skb);
+
+	if (skb_warn_if_lro(skb))
+		goto err;
+
+	skb_forward_csum(skb);
+
+	/* Verify ttl is valid */
+	if (dec.ttl <= 1)
+		goto err;
+
+	/* Find the output device */
+	out_dev = nh->nh_dev;
+	if (!mpls_output_possible(out_dev))
+		goto tx_err;
+
+	/* 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 tx_err;
+
+	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 tx_err;
+
+	skb->dev = out_dev;
+	skb->protocol = htons(ETH_P_MPLS_UC);
+
+	dec.ttl -= 1;
+	if (unlikely(!new_header_size && dec.bos)) {
+		/* Penultimate hop popping */
+		if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
+			goto err;
+	} 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;
+		}
+	}
+
+	mpls_stats_inc_outucastpkts(out_dev, skb);
+
+	/* If via wasn't specified then send out using device address */
+	if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
+		err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
+				 out_dev->dev_addr, skb);
+	else
+		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;
+
+tx_err:
+	out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
+	if (out_mdev)
+		MPLS_INC_STATS(out_mdev, tx_errors);
+	goto drop;
+err:
+	MPLS_INC_STATS(mdev, rx_errors);
+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 },
+	[RTA_TTL_PROPAGATE]	= { .type = NLA_U8 },
+};
+
+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_ttl_propagate;
+	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;
+};
+
+/* all nexthops within a route have the same size based on max
+ * number of labels and max via length for a hop
+ */
+static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
+{
+	u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
+	struct mpls_route *rt;
+	size_t size;
+
+	size = sizeof(*rt) + num_nh * nh_size;
+	if (size > MAX_MPLS_ROUTE_MEM)
+		return ERR_PTR(-EINVAL);
+
+	rt = kzalloc(size, GFP_KERNEL);
+	if (!rt)
+		return ERR_PTR(-ENOMEM);
+
+	rt->rt_nhn = num_nh;
+	rt->rt_nhn_alive = num_nh;
+	rt->rt_nh_size = nh_size;
+	rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
+
+	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;
+
+	if (!ipv6_stub)
+		return ERR_PTR(-EAFNOSUPPORT);
+
+	memset(&fl6, 0, sizeof(fl6));
+	memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
+	dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
+	if (IS_ERR(dst))
+		return ERR_CAST(dst);
+
+	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);
+
+	if (IS_ERR(dev))
+		return dev;
+
+	/* 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;
+
+	if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
+	    (dev->addr_len != nh->nh_via_alen))
+		goto errout;
+
+	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 nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
+		       u8 via_addr[], struct netlink_ext_ack *extack)
+{
+	struct rtvia *via = nla_data(nla);
+	int err = -EINVAL;
+	int alen;
+
+	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid attribute length for RTA_VIA");
+		goto errout;
+	}
+	alen = nla_len(nla) -
+			offsetof(struct rtvia, rtvia_addr);
+	if (alen > MAX_VIA_ALEN) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid address length for RTA_VIA");
+		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 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;
+
+	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, u8 max_labels,
+			 struct netlink_ext_ack *extack)
+{
+	int err = -ENOMEM;
+
+	if (!nh)
+		goto errout;
+
+	if (newdst) {
+		err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
+				     nh->nh_label, extack);
+		if (err)
+			goto errout;
+	}
+
+	if (via) {
+		err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
+				  __mpls_nh_via(rt, nh), extack);
+		if (err)
+			goto errout;
+	} else {
+		nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
+	}
+
+	err = mpls_nh_assign_dev(net, rt, nh, oif);
+	if (err)
+		goto errout;
+
+	return 0;
+
+errout:
+	return err;
+}
+
+static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
+			      u8 cfg_via_alen, u8 *max_via_alen,
+			      u8 *max_labels)
+{
+	int remaining = len;
+	u8 nhs = 0;
+
+	*max_via_alen = 0;
+	*max_labels = 0;
+
+	while (rtnh_ok(rtnh, remaining)) {
+		struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+		int attrlen;
+		u8 n_labels = 0;
+
+		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);
+		}
+
+		nla = nla_find(attrs, attrlen, RTA_NEWDST);
+		if (nla &&
+		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
+				   NULL, NULL) != 0)
+			return 0;
+
+		*max_labels = max_t(u8, *max_labels, n_labels);
+
+		/* number of nexthops is tracked by a u8.
+		 * Check for overflow.
+		 */
+		if (nhs == 255)
+			return 0;
+		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, u8 max_labels,
+			       struct netlink_ext_ack *extack)
+{
+	struct rtnexthop *rtnh = cfg->rc_mp;
+	struct nlattr *nla_via, *nla_newdst;
+	int remaining = cfg->rc_mp_len;
+	int err = 0;
+	u8 nhs = 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);
+		}
+
+		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
+				    rtnh->rtnh_ifindex, nla_via, nla_newdst,
+				    max_labels, extack);
+		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 bool mpls_label_ok(struct net *net, unsigned int *index,
+			  struct netlink_ext_ack *extack)
+{
+	bool is_ok = true;
+
+	/* Reserved labels may not be set */
+	if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
+		is_ok = false;
+	}
+
+	/* The full 20 bit range may not be supported. */
+	if (is_ok && *index >= net->mpls.platform_labels) {
+		NL_SET_ERR_MSG(extack,
+			       "Label >= configured maximum in platform_labels");
+		is_ok = false;
+	}
+
+	*index = array_index_nospec(*index, net->mpls.platform_labels);
+	return is_ok;
+}
+
+static int mpls_route_add(struct mpls_route_config *cfg,
+			  struct netlink_ext_ack *extack)
+{
+	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;
+	u8 max_labels;
+	u8 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);
+	}
+
+	if (!mpls_label_ok(net, &index, extack))
+		goto errout;
+
+	/* Append makes no sense with mpls */
+	err = -EOPNOTSUPP;
+	if (cfg->rc_nlflags & NLM_F_APPEND) {
+		NL_SET_ERR_MSG(extack, "MPLS does not support route 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;
+	if (cfg->rc_mp) {
+		nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
+					  cfg->rc_via_alen, &max_via_alen,
+					  &max_labels);
+	} else {
+		max_via_alen = cfg->rc_via_alen;
+		max_labels = cfg->rc_output_labels;
+		nhs = 1;
+	}
+
+	if (nhs == 0) {
+		NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
+		goto errout;
+	}
+
+	rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
+	if (IS_ERR(rt)) {
+		err = PTR_ERR(rt);
+		goto errout;
+	}
+
+	rt->rt_protocol = cfg->rc_protocol;
+	rt->rt_payload_type = cfg->rc_payload_type;
+	rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
+
+	if (cfg->rc_mp)
+		err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
+	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 netlink_ext_ack *extack)
+{
+	struct net *net = cfg->rc_nlinfo.nl_net;
+	unsigned index;
+	int err = -EINVAL;
+
+	index = cfg->rc_label;
+
+	if (!mpls_label_ok(net, &index, extack))
+		goto errout;
+
+	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
+
+	err = 0;
+errout:
+	return err;
+}
+
+static void mpls_get_stats(struct mpls_dev *mdev,
+			   struct mpls_link_stats *stats)
+{
+	struct mpls_pcpu_stats *p;
+	int i;
+
+	memset(stats, 0, sizeof(*stats));
+
+	for_each_possible_cpu(i) {
+		struct mpls_link_stats local;
+		unsigned int start;
+
+		p = per_cpu_ptr(mdev->stats, i);
+		do {
+			start = u64_stats_fetch_begin_irq(&p->syncp);
+			local = p->stats;
+		} while (u64_stats_fetch_retry_irq(&p->syncp, start));
+
+		stats->rx_packets	+= local.rx_packets;
+		stats->rx_bytes		+= local.rx_bytes;
+		stats->tx_packets	+= local.tx_packets;
+		stats->tx_bytes		+= local.tx_bytes;
+		stats->rx_errors	+= local.rx_errors;
+		stats->tx_errors	+= local.tx_errors;
+		stats->rx_dropped	+= local.rx_dropped;
+		stats->tx_dropped	+= local.tx_dropped;
+		stats->rx_noroute	+= local.rx_noroute;
+	}
+}
+
+static int mpls_fill_stats_af(struct sk_buff *skb,
+			      const struct net_device *dev)
+{
+	struct mpls_link_stats *stats;
+	struct mpls_dev *mdev;
+	struct nlattr *nla;
+
+	mdev = mpls_dev_get(dev);
+	if (!mdev)
+		return -ENODATA;
+
+	nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
+				sizeof(struct mpls_link_stats),
+				MPLS_STATS_UNSPEC);
+	if (!nla)
+		return -EMSGSIZE;
+
+	stats = nla_data(nla);
+	mpls_get_stats(mdev, stats);
+
+	return 0;
+}
+
+static size_t mpls_get_stats_af_size(const struct net_device *dev)
+{
+	struct mpls_dev *mdev;
+
+	mdev = mpls_dev_get(dev);
+	if (!mdev)
+		return 0;
+
+	return nla_total_size_64bit(sizeof(struct mpls_link_stats));
+}
+
+static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
+				     u32 portid, u32 seq, int event,
+				     unsigned int flags, int type)
+{
+	struct nlmsghdr  *nlh;
+	struct netconfmsg *ncm;
+	bool all = false;
+
+	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
+			flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	if (type == NETCONFA_ALL)
+		all = true;
+
+	ncm = nlmsg_data(nlh);
+	ncm->ncm_family = AF_MPLS;
+
+	if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
+		goto nla_put_failure;
+
+	if ((all || type == NETCONFA_INPUT) &&
+	    nla_put_s32(skb, NETCONFA_INPUT,
+			mdev->input_enabled) < 0)
+		goto nla_put_failure;
+
+	nlmsg_end(skb, nlh);
+	return 0;
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int mpls_netconf_msgsize_devconf(int type)
+{
+	int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
+			+ nla_total_size(4); /* NETCONFA_IFINDEX */
+	bool all = false;
+
+	if (type == NETCONFA_ALL)
+		all = true;
+
+	if (all || type == NETCONFA_INPUT)
+		size += nla_total_size(4);
+
+	return size;
+}
+
+static void mpls_netconf_notify_devconf(struct net *net, int event,
+					int type, struct mpls_dev *mdev)
+{
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
+	if (!skb)
+		goto errout;
+
+	err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+
+	rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
+	return;
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
+}
+
+static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
+	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
+};
+
+static int mpls_netconf_valid_get_req(struct sk_buff *skb,
+				      const struct nlmsghdr *nlh,
+				      struct nlattr **tb,
+				      struct netlink_ext_ack *extack)
+{
+	int i, err;
+
+	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid header for netconf get request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
+					      tb, NETCONFA_MAX,
+					      devconf_mpls_policy, extack);
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
+					    tb, NETCONFA_MAX,
+					    devconf_mpls_policy, extack);
+	if (err)
+		return err;
+
+	for (i = 0; i <= NETCONFA_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case NETCONFA_IFINDEX:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
+				    struct nlmsghdr *nlh,
+				    struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct nlattr *tb[NETCONFA_MAX + 1];
+	struct net_device *dev;
+	struct mpls_dev *mdev;
+	struct sk_buff *skb;
+	int ifindex;
+	int err;
+
+	err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
+	if (err < 0)
+		goto errout;
+
+	err = -EINVAL;
+	if (!tb[NETCONFA_IFINDEX])
+		goto errout;
+
+	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
+	dev = __dev_get_by_index(net, ifindex);
+	if (!dev)
+		goto errout;
+
+	mdev = mpls_dev_get(dev);
+	if (!mdev)
+		goto errout;
+
+	err = -ENOBUFS;
+	skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
+	if (!skb)
+		goto errout;
+
+	err = mpls_netconf_fill_devconf(skb, mdev,
+					NETLINK_CB(in_skb).portid,
+					nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
+					NETCONFA_ALL);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+errout:
+	return err;
+}
+
+static int mpls_netconf_dump_devconf(struct sk_buff *skb,
+				     struct netlink_callback *cb)
+{
+	const struct nlmsghdr *nlh = cb->nlh;
+	struct net *net = sock_net(skb->sk);
+	struct hlist_head *head;
+	struct net_device *dev;
+	struct mpls_dev *mdev;
+	int idx, s_idx;
+	int h, s_h;
+
+	if (cb->strict_check) {
+		struct netlink_ext_ack *extack = cb->extack;
+		struct netconfmsg *ncm;
+
+		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
+			return -EINVAL;
+		}
+
+		if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
+			return -EINVAL;
+		}
+	}
+
+	s_h = cb->args[0];
+	s_idx = idx = cb->args[1];
+
+	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
+		idx = 0;
+		head = &net->dev_index_head[h];
+		rcu_read_lock();
+		cb->seq = net->dev_base_seq;
+		hlist_for_each_entry_rcu(dev, head, index_hlist) {
+			if (idx < s_idx)
+				goto cont;
+			mdev = mpls_dev_get(dev);
+			if (!mdev)
+				goto cont;
+			if (mpls_netconf_fill_devconf(skb, mdev,
+						      NETLINK_CB(cb->skb).portid,
+						      nlh->nlmsg_seq,
+						      RTM_NEWNETCONF,
+						      NLM_F_MULTI,
+						      NETCONFA_ALL) < 0) {
+				rcu_read_unlock();
+				goto done;
+			}
+			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+cont:
+			idx++;
+		}
+		rcu_read_unlock();
+	}
+done:
+	cb->args[0] = h;
+	cb->args[1] = idx;
+
+	return skb->len;
+}
+
+#define MPLS_PERDEV_SYSCTL_OFFSET(field)	\
+	(&((struct mpls_dev *)0)->field)
+
+static int mpls_conf_proc(struct ctl_table *ctl, int write,
+			  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int oval = *(int *)ctl->data;
+	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
+
+	if (write) {
+		struct mpls_dev *mdev = ctl->extra1;
+		int i = (int *)ctl->data - (int *)mdev;
+		struct net *net = ctl->extra2;
+		int val = *(int *)ctl->data;
+
+		if (i == offsetof(struct mpls_dev, input_enabled) &&
+		    val != oval) {
+			mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
+						    NETCONFA_INPUT, mdev);
+		}
+	}
+
+	return ret;
+}
+
+static const struct ctl_table mpls_dev_table[] = {
+	{
+		.procname	= "input",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= mpls_conf_proc,
+		.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 net *net = dev_net(dev);
+	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;
+		table[i].extra1 = mdev;
+		table[i].extra2 = net;
+	}
+
+	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
+
+	mdev->sysctl = register_net_sysctl(net, path, table);
+	if (!mdev->sysctl)
+		goto free;
+
+	mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
+	return 0;
+
+free:
+	kfree(table);
+out:
+	mdev->sysctl = NULL;
+	return -ENOBUFS;
+}
+
+static void mpls_dev_sysctl_unregister(struct net_device *dev,
+				       struct mpls_dev *mdev)
+{
+	struct net *net = dev_net(dev);
+	struct ctl_table *table;
+
+	if (!mdev->sysctl)
+		return;
+
+	table = mdev->sysctl->ctl_table_arg;
+	unregister_net_sysctl_table(mdev->sysctl);
+	kfree(table);
+
+	mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
+}
+
+static struct mpls_dev *mpls_add_dev(struct net_device *dev)
+{
+	struct mpls_dev *mdev;
+	int err = -ENOMEM;
+	int i;
+
+	ASSERT_RTNL();
+
+	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return ERR_PTR(err);
+
+	mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
+	if (!mdev->stats)
+		goto free;
+
+	for_each_possible_cpu(i) {
+		struct mpls_pcpu_stats *mpls_stats;
+
+		mpls_stats = per_cpu_ptr(mdev->stats, i);
+		u64_stats_init(&mpls_stats->syncp);
+	}
+
+	mdev->dev = dev;
+
+	err = mpls_dev_sysctl_register(dev, mdev);
+	if (err)
+		goto free;
+
+	rcu_assign_pointer(dev->mpls_ptr, mdev);
+
+	return mdev;
+
+free:
+	free_percpu(mdev->stats);
+	kfree(mdev);
+	return ERR_PTR(err);
+}
+
+static void mpls_dev_destroy_rcu(struct rcu_head *head)
+{
+	struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
+
+	free_percpu(mdev->stats);
+	kfree(mdev);
+}
+
+static int 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]);
+		bool nh_del = false;
+		u8 alive = 0;
+
+		if (!rt)
+			continue;
+
+		if (event == NETDEV_UNREGISTER) {
+			u8 deleted = 0;
+
+			for_nexthops(rt) {
+				if (!nh->nh_dev || nh->nh_dev == dev)
+					deleted++;
+				if (nh->nh_dev == dev)
+					nh_del = true;
+			} endfor_nexthops(rt);
+
+			/* if there are no more nexthops, delete the route */
+			if (deleted == rt->rt_nhn) {
+				mpls_route_update(net, index, NULL, NULL);
+				continue;
+			}
+
+			if (nh_del) {
+				size_t size = sizeof(*rt) + rt->rt_nhn *
+					rt->rt_nh_size;
+				struct mpls_route *orig = rt;
+
+				rt = kmemdup(orig, size, GFP_KERNEL);
+				if (!rt)
+					return -ENOMEM;
+			}
+		}
+
+		change_nexthops(rt) {
+			unsigned int nh_flags = nh->nh_flags;
+
+			if (nh->nh_dev != dev)
+				goto next;
+
+			switch (event) {
+			case NETDEV_DOWN:
+			case NETDEV_UNREGISTER:
+				nh_flags |= RTNH_F_DEAD;
+				fallthrough;
+			case NETDEV_CHANGE:
+				nh_flags |= RTNH_F_LINKDOWN;
+				break;
+			}
+			if (event == NETDEV_UNREGISTER)
+				nh->nh_dev = NULL;
+
+			if (nh->nh_flags != nh_flags)
+				WRITE_ONCE(nh->nh_flags, nh_flags);
+next:
+			if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
+				alive++;
+		} endfor_nexthops(rt);
+
+		WRITE_ONCE(rt->rt_nhn_alive, alive);
+
+		if (nh_del)
+			mpls_route_update(net, index, rt, NULL);
+	}
+
+	return 0;
+}
+
+static void mpls_ifup(struct net_device *dev, unsigned int flags)
+{
+	struct mpls_route __rcu **platform_label;
+	struct net *net = dev_net(dev);
+	unsigned index;
+	u8 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) {
+			unsigned int nh_flags = nh->nh_flags;
+
+			if (!(nh_flags & flags)) {
+				alive++;
+				continue;
+			}
+			if (nh->nh_dev != dev)
+				continue;
+			alive++;
+			nh_flags &= ~flags;
+			WRITE_ONCE(nh->nh_flags, nh_flags);
+		} endfor_nexthops(rt);
+
+		WRITE_ONCE(rt->rt_nhn_alive, alive);
+	}
+}
+
+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;
+	int err;
+
+	if (event == NETDEV_REGISTER) {
+		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:
+		err = mpls_ifdown(dev, event);
+		if (err)
+			return notifier_from_errno(err);
+		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 {
+			err = mpls_ifdown(dev, event);
+			if (err)
+				return notifier_from_errno(err);
+		}
+		break;
+	case NETDEV_UNREGISTER:
+		err = mpls_ifdown(dev, event);
+		if (err)
+			return notifier_from_errno(err);
+		mdev = mpls_dev_get(dev);
+		if (mdev) {
+			mpls_dev_sysctl_unregister(dev, mdev);
+			RCU_INIT_POINTER(dev->mpls_ptr, NULL);
+			call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
+		}
+		break;
+	case NETDEV_CHANGENAME:
+		mdev = mpls_dev_get(dev);
+		if (mdev) {
+			mpls_dev_sysctl_unregister(dev, 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, u8 max_labels, u8 *labels,
+		   u32 label[], struct netlink_ext_ack *extack)
+{
+	unsigned len = nla_len(nla);
+	struct mpls_shim_hdr *nla_label;
+	u8 nla_labels;
+	bool bos;
+	int i;
+
+	/* len needs to be an even multiple of 4 (the label size). Number
+	 * of labels is a u8 so check for overflow.
+	 */
+	if (len & 3 || len / 4 > 255) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid length for labels attribute");
+		return -EINVAL;
+	}
+
+	/* Limit the number of new labels allowed */
+	nla_labels = len/4;
+	if (nla_labels > max_labels) {
+		NL_SET_ERR_MSG(extack, "Too many labels");
+		return -EINVAL;
+	}
+
+	/* when label == NULL, caller wants number of labels */
+	if (!label)
+		goto out;
+
+	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.ttl) {
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "TTL in label must be 0");
+			return -EINVAL;
+		}
+
+		if (dec.tc) {
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "Traffic class in label must be 0");
+			return -EINVAL;
+		}
+
+		if (dec.bos != bos) {
+			NL_SET_BAD_ATTR(extack, nla);
+			if (bos) {
+				NL_SET_ERR_MSG(extack,
+					       "BOS bit must be set in first label");
+			} else {
+				NL_SET_ERR_MSG(extack,
+					       "BOS bit can only be set in first label");
+			}
+			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.
+			 */
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "Implicit NULL Label (3) can not be used in encapsulation");
+			return -EINVAL;
+		}
+
+		label[i] = dec.label;
+	}
+out:
+	*labels = nla_labels;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nla_get_labels);
+
+static int rtm_to_route_config(struct sk_buff *skb,
+			       struct nlmsghdr *nlh,
+			       struct mpls_route_config *cfg,
+			       struct netlink_ext_ack *extack)
+{
+	struct rtmsg *rtm;
+	struct nlattr *tb[RTA_MAX+1];
+	int index;
+	int err;
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
+				     rtm_mpls_policy, extack);
+	if (err < 0)
+		goto errout;
+
+	err = -EINVAL;
+	rtm = nlmsg_data(nlh);
+
+	if (rtm->rtm_family != AF_MPLS) {
+		NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
+		goto errout;
+	}
+	if (rtm->rtm_dst_len != 20) {
+		NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
+		goto errout;
+	}
+	if (rtm->rtm_src_len != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
+		goto errout;
+	}
+	if (rtm->rtm_tos != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
+		goto errout;
+	}
+	if (rtm->rtm_table != RT_TABLE_MAIN) {
+		NL_SET_ERR_MSG(extack,
+			       "MPLS only supports the main route table");
+		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) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid route scope  - MPLS only supports UNIVERSE");
+		goto errout;
+	}
+	if (rtm->rtm_type != RTN_UNICAST) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid route type - MPLS only supports UNICAST");
+		goto errout;
+	}
+	if (rtm->rtm_flags != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
+		goto errout;
+	}
+
+	cfg->rc_label		= LABEL_NOT_SPECIFIED;
+	cfg->rc_protocol	= rtm->rtm_protocol;
+	cfg->rc_via_table	= MPLS_NEIGH_TABLE_UNSPEC;
+	cfg->rc_ttl_propagate	= MPLS_TTL_PROP_DEFAULT;
+	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, extack))
+				goto errout;
+			break;
+		case RTA_DST:
+		{
+			u8 label_count;
+			if (nla_get_labels(nla, 1, &label_count,
+					   &cfg->rc_label, extack))
+				goto errout;
+
+			if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
+					   &cfg->rc_label, extack))
+				goto errout;
+			break;
+		}
+		case RTA_GATEWAY:
+			NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
+			goto errout;
+		case RTA_VIA:
+		{
+			if (nla_get_via(nla, &cfg->rc_via_alen,
+					&cfg->rc_via_table, cfg->rc_via,
+					extack))
+				goto errout;
+			break;
+		}
+		case RTA_MULTIPATH:
+		{
+			cfg->rc_mp = nla_data(nla);
+			cfg->rc_mp_len = nla_len(nla);
+			break;
+		}
+		case RTA_TTL_PROPAGATE:
+		{
+			u8 ttl_propagate = nla_get_u8(nla);
+
+			if (ttl_propagate > 1) {
+				NL_SET_ERR_MSG_ATTR(extack, nla,
+						    "RTA_TTL_PROPAGATE can only be 0 or 1");
+				goto errout;
+			}
+			cfg->rc_ttl_propagate = ttl_propagate ?
+				MPLS_TTL_PROP_ENABLED :
+				MPLS_TTL_PROP_DISABLED;
+			break;
+		}
+		default:
+			NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
+			/* Unsupported attribute */
+			goto errout;
+		}
+	}
+
+	err = 0;
+errout:
+	return err;
+}
+
+static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	struct mpls_route_config *cfg;
+	int err;
+
+	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return -ENOMEM;
+
+	err = rtm_to_route_config(skb, nlh, cfg, extack);
+	if (err < 0)
+		goto out;
+
+	err = mpls_route_del(cfg, extack);
+out:
+	kfree(cfg);
+
+	return err;
+}
+
+
+static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	struct mpls_route_config *cfg;
+	int err;
+
+	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return -ENOMEM;
+
+	err = rtm_to_route_config(skb, nlh, cfg, extack);
+	if (err < 0)
+		goto out;
+
+	err = mpls_route_add(cfg, extack);
+out:
+	kfree(cfg);
+
+	return err;
+}
+
+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_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
+		bool ttl_propagate =
+			rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
+
+		if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
+			       ttl_propagate))
+			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 (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
+		    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
+				nh->nh_via_alen))
+			goto nla_put_failure;
+		dev = 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;
+		u8 linkdown = 0;
+		u8 dead = 0;
+
+		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
+		if (!mp)
+			goto nla_put_failure;
+
+		for_nexthops(rt) {
+			dev = nh->nh_dev;
+			if (!dev)
+				continue;
+
+			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
+			if (!rtnh)
+				goto nla_put_failure;
+
+			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 (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
+			    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;
+}
+
+#if IS_ENABLED(CONFIG_INET)
+static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
+				   struct fib_dump_filter *filter,
+				   struct netlink_callback *cb)
+{
+	return ip_valid_fib_dump_req(net, nlh, filter, cb);
+}
+#else
+static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
+				   struct fib_dump_filter *filter,
+				   struct netlink_callback *cb)
+{
+	struct netlink_ext_ack *extack = cb->extack;
+	struct nlattr *tb[RTA_MAX + 1];
+	struct rtmsg *rtm;
+	int err, i;
+
+	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
+		return -EINVAL;
+	}
+
+	rtm = nlmsg_data(nlh);
+	if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
+	    rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
+	    rtm->rtm_flags) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
+		return -EINVAL;
+	}
+
+	if (rtm->rtm_protocol) {
+		filter->protocol = rtm->rtm_protocol;
+		filter->filter_set = 1;
+		cb->answer_flags = NLM_F_DUMP_FILTERED;
+	}
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
+					    rtm_mpls_policy, extack);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i <= RTA_MAX; ++i) {
+		int ifindex;
+
+		if (i == RTA_OIF) {
+			ifindex = nla_get_u32(tb[i]);
+			filter->dev = __dev_get_by_index(net, ifindex);
+			if (!filter->dev)
+				return -ENODEV;
+			filter->filter_set = 1;
+		} else if (tb[i]) {
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+#endif
+
+static bool mpls_rt_uses_dev(struct mpls_route *rt,
+			     const struct net_device *dev)
+{
+	if (rt->rt_nhn == 1) {
+		struct mpls_nh *nh = rt->rt_nh;
+
+		if (nh->nh_dev == dev)
+			return true;
+	} else {
+		for_nexthops(rt) {
+			if (nh->nh_dev == dev)
+				return true;
+		} endfor_nexthops(rt);
+	}
+
+	return false;
+}
+
+static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	const struct nlmsghdr *nlh = cb->nlh;
+	struct net *net = sock_net(skb->sk);
+	struct mpls_route __rcu **platform_label;
+	struct fib_dump_filter filter = {};
+	unsigned int flags = NLM_F_MULTI;
+	size_t platform_labels;
+	unsigned int index;
+
+	ASSERT_RTNL();
+
+	if (cb->strict_check) {
+		int err;
+
+		err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
+		if (err < 0)
+			return err;
+
+		/* for MPLS, there is only 1 table with fixed type and flags.
+		 * If either are set in the filter then return nothing.
+		 */
+		if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
+		    (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
+		     filter.flags)
+			return skb->len;
+	}
+
+	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;
+
+	if (filter.filter_set)
+		flags |= NLM_F_DUMP_FILTERED;
+
+	for (; index < platform_labels; index++) {
+		struct mpls_route *rt;
+
+		rt = rtnl_dereference(platform_label[index]);
+		if (!rt)
+			continue;
+
+		if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
+		    (filter.protocol && rt->rt_protocol != filter.protocol))
+			continue;
+
+		if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
+				    cb->nlh->nlmsg_seq, RTM_NEWROUTE,
+				    index, rt, flags) < 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 */
+		+ nla_total_size(1);			/* RTA_TTL_PROPAGATE */
+
+	if (rt->rt_nhn == 1) {
+		struct mpls_nh *nh = rt->rt_nh;
+
+		if (nh->nh_dev)
+			payload += nla_total_size(4); /* RTA_OIF */
+		if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
+			payload += nla_total_size(2 + nh->nh_via_alen);
+		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) {
+			if (!nh->nh_dev)
+				continue;
+			nhsize += nla_total_size(sizeof(struct rtnexthop));
+			/* RTA_VIA */
+			if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
+				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 mpls_valid_getroute_req(struct sk_buff *skb,
+				   const struct nlmsghdr *nlh,
+				   struct nlattr **tb,
+				   struct netlink_ext_ack *extack)
+{
+	struct rtmsg *rtm;
+	int i, err;
+
+	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid header for get route request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
+					      rtm_mpls_policy, extack);
+
+	rtm = nlmsg_data(nlh);
+	if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
+	    rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
+	    rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
+		return -EINVAL;
+	}
+	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid flags for get route request");
+		return -EINVAL;
+	}
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
+					    rtm_mpls_policy, extack);
+	if (err)
+		return err;
+
+	if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
+		NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
+		return -EINVAL;
+	}
+
+	for (i = 0; i <= RTA_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case RTA_DST:
+		case RTA_NEWDST:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
+			 struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	u32 portid = NETLINK_CB(in_skb).portid;
+	u32 in_label = LABEL_NOT_SPECIFIED;
+	struct nlattr *tb[RTA_MAX + 1];
+	u32 labels[MAX_NEW_LABELS];
+	struct mpls_shim_hdr *hdr;
+	unsigned int hdr_size = 0;
+	const struct mpls_nh *nh;
+	struct net_device *dev;
+	struct mpls_route *rt;
+	struct rtmsg *rtm, *r;
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+	u8 n_labels;
+	int err;
+
+	err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
+	if (err < 0)
+		goto errout;
+
+	rtm = nlmsg_data(in_nlh);
+
+	if (tb[RTA_DST]) {
+		u8 label_count;
+
+		if (nla_get_labels(tb[RTA_DST], 1, &label_count,
+				   &in_label, extack)) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		if (!mpls_label_ok(net, &in_label, extack)) {
+			err = -EINVAL;
+			goto errout;
+		}
+	}
+
+	rt = mpls_route_input_rcu(net, in_label);
+	if (!rt) {
+		err = -ENETUNREACH;
+		goto errout;
+	}
+
+	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
+		skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
+		if (!skb) {
+			err = -ENOBUFS;
+			goto errout;
+		}
+
+		err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
+				      RTM_NEWROUTE, in_label, rt, 0);
+		if (err < 0) {
+			/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
+			WARN_ON(err == -EMSGSIZE);
+			goto errout_free;
+		}
+
+		return rtnl_unicast(skb, net, portid);
+	}
+
+	if (tb[RTA_NEWDST]) {
+		if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
+				   labels, extack) != 0) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
+	}
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb) {
+		err = -ENOBUFS;
+		goto errout;
+	}
+
+	skb->protocol = htons(ETH_P_MPLS_UC);
+
+	if (hdr_size) {
+		bool bos;
+		int i;
+
+		if (skb_cow(skb, hdr_size)) {
+			err = -ENOBUFS;
+			goto errout_free;
+		}
+
+		skb_reserve(skb, hdr_size);
+		skb_push(skb, hdr_size);
+		skb_reset_network_header(skb);
+
+		/* Push new labels */
+		hdr = mpls_hdr(skb);
+		bos = true;
+		for (i = n_labels - 1; i >= 0; i--) {
+			hdr[i] = mpls_entry_encode(labels[i],
+						   1, 0, bos);
+			bos = false;
+		}
+	}
+
+	nh = mpls_select_multipath(rt, skb);
+	if (!nh) {
+		err = -ENETUNREACH;
+		goto errout_free;
+	}
+
+	if (hdr_size) {
+		skb_pull(skb, hdr_size);
+		skb_reset_network_header(skb);
+	}
+
+	nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
+			RTM_NEWROUTE, sizeof(*r), 0);
+	if (!nlh) {
+		err = -EMSGSIZE;
+		goto errout_free;
+	}
+
+	r = nlmsg_data(nlh);
+	r->rtm_family	 = AF_MPLS;
+	r->rtm_dst_len	= 20;
+	r->rtm_src_len	= 0;
+	r->rtm_table	= RT_TABLE_MAIN;
+	r->rtm_type	= RTN_UNICAST;
+	r->rtm_scope	= RT_SCOPE_UNIVERSE;
+	r->rtm_protocol = rt->rt_protocol;
+	r->rtm_flags	= 0;
+
+	if (nla_put_labels(skb, RTA_DST, 1, &in_label))
+		goto nla_put_failure;
+
+	if (nh->nh_labels &&
+	    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
+			   nh->nh_label))
+		goto nla_put_failure;
+
+	if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
+	    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
+			nh->nh_via_alen))
+		goto nla_put_failure;
+	dev = nh->nh_dev;
+	if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
+		goto nla_put_failure;
+
+	nlmsg_end(skb, nlh);
+
+	err = rtnl_unicast(skb, net, portid);
+errout:
+	return err;
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	err = -EMSGSIZE;
+errout_free:
+	kfree_skb(skb);
+	return 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 = kvzalloc(size, GFP_KERNEL);
+		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, 0);
+		if (IS_ERR(rt0))
+			goto nort0;
+		rt0->rt_nh->nh_dev = lo;
+		rt0->rt_protocol = RTPROT_KERNEL;
+		rt0->rt_payload_type = MPT_IPV4;
+		rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
+		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, 0);
+		if (IS_ERR(rt2))
+			goto nort2;
+		rt2->rt_nh->nh_dev = lo;
+		rt2->rt_protocol = RTPROT_KERNEL;
+		rt2->rt_payload_type = MPT_IPV6;
+		rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
+		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 *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		= SYSCTL_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;
+}
+
+#define MPLS_NS_SYSCTL_OFFSET(field)		\
+	(&((struct net *)0)->field)
+
+static const struct ctl_table mpls_table[] = {
+	{
+		.procname	= "platform_labels",
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= mpls_platform_labels,
+	},
+	{
+		.procname	= "ip_ttl_propagate",
+		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "default_ttl",
+		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ONE,
+		.extra2		= &ttl_max,
+	},
+	{ }
+};
+
+static int mpls_net_init(struct net *net)
+{
+	struct ctl_table *table;
+	int i;
+
+	net->mpls.platform_labels = 0;
+	net->mpls.platform_label = NULL;
+	net->mpls.ip_ttl_propagate = 1;
+	net->mpls.default_ttl = 255;
+
+	table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
+	if (table == NULL)
+		return -ENOMEM;
+
+	/* 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_table) - 1; i++)
+		table[i].data = (char *)net + (uintptr_t)table[i].data;
+
+	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_notify_route(net, index, rt, NULL, 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 struct rtnl_af_ops mpls_af_ops __read_mostly = {
+	.family		   = AF_MPLS,
+	.fill_stats_af	   = mpls_fill_stats_af,
+	.get_stats_af_size = mpls_get_stats_af_size,
+};
+
+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_af_register(&mpls_af_ops);
+
+	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
+			     mpls_rtm_newroute, NULL, 0);
+	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
+			     mpls_rtm_delroute, NULL, 0);
+	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
+			     mpls_getroute, mpls_dump_routes, 0);
+	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
+			     mpls_netconf_get_devconf,
+			     mpls_netconf_dump_devconf, 0);
+	err = ipgre_tunnel_encap_add_mpls_ops();
+	if (err)
+		pr_err("Can't add mpls over gre tunnel ops\n");
+
+	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);
+	rtnl_af_unregister(&mpls_af_ops);
+	dev_remove_pack(&mpls_packet_type);
+	unregister_netdevice_notifier(&mpls_dev_notifier);
+	unregister_pernet_subsys(&mpls_net_ops);
+	ipgre_tunnel_encap_del_mpls_ops();
+}
+module_exit(mpls_exit);
+
+MODULE_DESCRIPTION("MultiProtocol Label Switching");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_NETPROTO(PF_MPLS);