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   1// SPDX-License-Identifier: GPL-2.0-only
   2#include <linux/types.h>
   3#include <linux/skbuff.h>
   4#include <linux/socket.h>
   5#include <linux/sysctl.h>
   6#include <linux/net.h>
   7#include <linux/module.h>
   8#include <linux/if_arp.h>
   9#include <linux/ipv6.h>
  10#include <linux/mpls.h>
  11#include <linux/netconf.h>
  12#include <linux/nospec.h>
  13#include <linux/vmalloc.h>
  14#include <linux/percpu.h>
  15#include <net/ip.h>
  16#include <net/dst.h>
  17#include <net/sock.h>
  18#include <net/arp.h>
  19#include <net/ip_fib.h>
  20#include <net/netevent.h>
  21#include <net/ip_tunnels.h>
  22#include <net/netns/generic.h>
  23#if IS_ENABLED(CONFIG_IPV6)
  24#include <net/ipv6.h>
  25#endif
  26#include <net/ipv6_stubs.h>
  27#include <net/rtnh.h>
  28#include "internal.h"
  29
  30/* max memory we will use for mpls_route */
  31#define MAX_MPLS_ROUTE_MEM	4096
  32
  33/* Maximum number of labels to look ahead at when selecting a path of
  34 * a multipath route
  35 */
  36#define MAX_MP_SELECT_LABELS 4
  37
  38#define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
  39
  40static int label_limit = (1 << 20) - 1;
  41static int ttl_max = 255;
  42
  43#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
  44static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
  45{
  46	return sizeof(struct mpls_shim_hdr);
  47}
  48
  49static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
  50	.encap_hlen	= ipgre_mpls_encap_hlen,
  51};
  52
  53static int ipgre_tunnel_encap_add_mpls_ops(void)
  54{
  55	return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
  56}
  57
  58static void ipgre_tunnel_encap_del_mpls_ops(void)
  59{
  60	ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
  61}
  62#else
  63static int ipgre_tunnel_encap_add_mpls_ops(void)
  64{
  65	return 0;
  66}
  67
  68static void ipgre_tunnel_encap_del_mpls_ops(void)
  69{
  70}
  71#endif
  72
  73static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
  74		       struct nlmsghdr *nlh, struct net *net, u32 portid,
  75		       unsigned int nlm_flags);
  76
  77static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
  78{
  79	struct mpls_route *rt = NULL;
  80
  81	if (index < net->mpls.platform_labels) {
  82		struct mpls_route __rcu **platform_label =
  83			rcu_dereference(net->mpls.platform_label);
  84		rt = rcu_dereference(platform_label[index]);
  85	}
  86	return rt;
  87}
  88
  89bool mpls_output_possible(const struct net_device *dev)
  90{
  91	return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
  92}
  93EXPORT_SYMBOL_GPL(mpls_output_possible);
  94
  95static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
  96{
  97	return (u8 *)nh + rt->rt_via_offset;
  98}
  99
 100static const u8 *mpls_nh_via(const struct mpls_route *rt,
 101			     const struct mpls_nh *nh)
 102{
 103	return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
 104}
 105
 106static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
 107{
 108	/* The size of the layer 2.5 labels to be added for this route */
 109	return nh->nh_labels * sizeof(struct mpls_shim_hdr);
 110}
 111
 112unsigned int mpls_dev_mtu(const struct net_device *dev)
 113{
 114	/* The amount of data the layer 2 frame can hold */
 115	return dev->mtu;
 116}
 117EXPORT_SYMBOL_GPL(mpls_dev_mtu);
 118
 119bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 120{
 121	if (skb->len <= mtu)
 122		return false;
 123
 124	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 125		return false;
 126
 127	return true;
 128}
 129EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
 130
 131void mpls_stats_inc_outucastpkts(struct net_device *dev,
 132				 const struct sk_buff *skb)
 133{
 134	struct mpls_dev *mdev;
 135
 136	if (skb->protocol == htons(ETH_P_MPLS_UC)) {
 137		mdev = mpls_dev_get(dev);
 138		if (mdev)
 139			MPLS_INC_STATS_LEN(mdev, skb->len,
 140					   tx_packets,
 141					   tx_bytes);
 142	} else if (skb->protocol == htons(ETH_P_IP)) {
 143		IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
 144#if IS_ENABLED(CONFIG_IPV6)
 145	} else if (skb->protocol == htons(ETH_P_IPV6)) {
 146		struct inet6_dev *in6dev = __in6_dev_get(dev);
 147
 148		if (in6dev)
 149			IP6_UPD_PO_STATS(dev_net(dev), in6dev,
 150					 IPSTATS_MIB_OUT, skb->len);
 151#endif
 152	}
 153}
 154EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
 155
 156static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
 157{
 158	struct mpls_entry_decoded dec;
 159	unsigned int mpls_hdr_len = 0;
 160	struct mpls_shim_hdr *hdr;
 161	bool eli_seen = false;
 162	int label_index;
 163	u32 hash = 0;
 164
 165	for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
 166	     label_index++) {
 167		mpls_hdr_len += sizeof(*hdr);
 168		if (!pskb_may_pull(skb, mpls_hdr_len))
 169			break;
 170
 171		/* Read and decode the current label */
 172		hdr = mpls_hdr(skb) + label_index;
 173		dec = mpls_entry_decode(hdr);
 174
 175		/* RFC6790 - reserved labels MUST NOT be used as keys
 176		 * for the load-balancing function
 177		 */
 178		if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
 179			hash = jhash_1word(dec.label, hash);
 180
 181			/* The entropy label follows the entropy label
 182			 * indicator, so this means that the entropy
 183			 * label was just added to the hash - no need to
 184			 * go any deeper either in the label stack or in the
 185			 * payload
 186			 */
 187			if (eli_seen)
 188				break;
 189		} else if (dec.label == MPLS_LABEL_ENTROPY) {
 190			eli_seen = true;
 191		}
 192
 193		if (!dec.bos)
 194			continue;
 195
 196		/* found bottom label; does skb have room for a header? */
 197		if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
 198			const struct iphdr *v4hdr;
 199
 200			v4hdr = (const struct iphdr *)(hdr + 1);
 201			if (v4hdr->version == 4) {
 202				hash = jhash_3words(ntohl(v4hdr->saddr),
 203						    ntohl(v4hdr->daddr),
 204						    v4hdr->protocol, hash);
 205			} else if (v4hdr->version == 6 &&
 206				   pskb_may_pull(skb, mpls_hdr_len +
 207						 sizeof(struct ipv6hdr))) {
 208				const struct ipv6hdr *v6hdr;
 209
 210				v6hdr = (const struct ipv6hdr *)(hdr + 1);
 211				hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
 212				hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
 213				hash = jhash_1word(v6hdr->nexthdr, hash);
 214			}
 215		}
 216
 217		break;
 218	}
 219
 220	return hash;
 221}
 222
 223static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
 224{
 225	return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
 226}
 227
 228/* number of alive nexthops (rt->rt_nhn_alive) and the flags for
 229 * a next hop (nh->nh_flags) are modified by netdev event handlers.
 230 * Since those fields can change at any moment, use READ_ONCE to
 231 * access both.
 232 */
 233static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
 234					     struct sk_buff *skb)
 235{
 236	u32 hash = 0;
 237	int nh_index = 0;
 238	int n = 0;
 239	u8 alive;
 240
 241	/* No need to look further into packet if there's only
 242	 * one path
 243	 */
 244	if (rt->rt_nhn == 1)
 245		return rt->rt_nh;
 246
 247	alive = READ_ONCE(rt->rt_nhn_alive);
 248	if (alive == 0)
 249		return NULL;
 250
 251	hash = mpls_multipath_hash(rt, skb);
 252	nh_index = hash % alive;
 253	if (alive == rt->rt_nhn)
 254		goto out;
 255	for_nexthops(rt) {
 256		unsigned int nh_flags = READ_ONCE(nh->nh_flags);
 257
 258		if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
 259			continue;
 260		if (n == nh_index)
 261			return nh;
 262		n++;
 263	} endfor_nexthops(rt);
 264
 265out:
 266	return mpls_get_nexthop(rt, nh_index);
 267}
 268
 269static bool mpls_egress(struct net *net, struct mpls_route *rt,
 270			struct sk_buff *skb, struct mpls_entry_decoded dec)
 271{
 272	enum mpls_payload_type payload_type;
 273	bool success = false;
 274
 275	/* The IPv4 code below accesses through the IPv4 header
 276	 * checksum, which is 12 bytes into the packet.
 277	 * The IPv6 code below accesses through the IPv6 hop limit
 278	 * which is 8 bytes into the packet.
 279	 *
 280	 * For all supported cases there should always be at least 12
 281	 * bytes of packet data present.  The IPv4 header is 20 bytes
 282	 * without options and the IPv6 header is always 40 bytes
 283	 * long.
 284	 */
 285	if (!pskb_may_pull(skb, 12))
 286		return false;
 287
 288	payload_type = rt->rt_payload_type;
 289	if (payload_type == MPT_UNSPEC)
 290		payload_type = ip_hdr(skb)->version;
 291
 292	switch (payload_type) {
 293	case MPT_IPV4: {
 294		struct iphdr *hdr4 = ip_hdr(skb);
 295		u8 new_ttl;
 296		skb->protocol = htons(ETH_P_IP);
 297
 298		/* If propagating TTL, take the decremented TTL from
 299		 * the incoming MPLS header, otherwise decrement the
 300		 * TTL, but only if not 0 to avoid underflow.
 301		 */
 302		if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
 303		    (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
 304		     net->mpls.ip_ttl_propagate))
 305			new_ttl = dec.ttl;
 306		else
 307			new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
 308
 309		csum_replace2(&hdr4->check,
 310			      htons(hdr4->ttl << 8),
 311			      htons(new_ttl << 8));
 312		hdr4->ttl = new_ttl;
 313		success = true;
 314		break;
 315	}
 316	case MPT_IPV6: {
 317		struct ipv6hdr *hdr6 = ipv6_hdr(skb);
 318		skb->protocol = htons(ETH_P_IPV6);
 319
 320		/* If propagating TTL, take the decremented TTL from
 321		 * the incoming MPLS header, otherwise decrement the
 322		 * hop limit, but only if not 0 to avoid underflow.
 323		 */
 324		if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
 325		    (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
 326		     net->mpls.ip_ttl_propagate))
 327			hdr6->hop_limit = dec.ttl;
 328		else if (hdr6->hop_limit)
 329			hdr6->hop_limit = hdr6->hop_limit - 1;
 330		success = true;
 331		break;
 332	}
 333	case MPT_UNSPEC:
 334		/* Should have decided which protocol it is by now */
 335		break;
 336	}
 337
 338	return success;
 339}
 340
 341static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
 342			struct packet_type *pt, struct net_device *orig_dev)
 343{
 344	struct net *net = dev_net(dev);
 345	struct mpls_shim_hdr *hdr;
 346	struct mpls_route *rt;
 347	struct mpls_nh *nh;
 348	struct mpls_entry_decoded dec;
 349	struct net_device *out_dev;
 350	struct mpls_dev *out_mdev;
 351	struct mpls_dev *mdev;
 352	unsigned int hh_len;
 353	unsigned int new_header_size;
 354	unsigned int mtu;
 355	int err;
 356
 357	/* Careful this entire function runs inside of an rcu critical section */
 358
 359	mdev = mpls_dev_get(dev);
 360	if (!mdev)
 361		goto drop;
 362
 363	MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
 364			   rx_bytes);
 365
 366	if (!mdev->input_enabled) {
 367		MPLS_INC_STATS(mdev, rx_dropped);
 368		goto drop;
 369	}
 370
 371	if (skb->pkt_type != PACKET_HOST)
 372		goto err;
 373
 374	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 375		goto err;
 376
 377	if (!pskb_may_pull(skb, sizeof(*hdr)))
 378		goto err;
 379
 380	/* Read and decode the label */
 381	hdr = mpls_hdr(skb);
 382	dec = mpls_entry_decode(hdr);
 383
 384	rt = mpls_route_input_rcu(net, dec.label);
 385	if (!rt) {
 386		MPLS_INC_STATS(mdev, rx_noroute);
 387		goto drop;
 388	}
 389
 390	nh = mpls_select_multipath(rt, skb);
 391	if (!nh)
 392		goto err;
 393
 394	/* Pop the label */
 395	skb_pull(skb, sizeof(*hdr));
 396	skb_reset_network_header(skb);
 397
 398	skb_orphan(skb);
 399
 400	if (skb_warn_if_lro(skb))
 401		goto err;
 402
 403	skb_forward_csum(skb);
 404
 405	/* Verify ttl is valid */
 406	if (dec.ttl <= 1)
 407		goto err;
 408	dec.ttl -= 1;
 409
 410	/* Find the output device */
 411	out_dev = rcu_dereference(nh->nh_dev);
 412	if (!mpls_output_possible(out_dev))
 413		goto tx_err;
 414
 415	/* Verify the destination can hold the packet */
 416	new_header_size = mpls_nh_header_size(nh);
 417	mtu = mpls_dev_mtu(out_dev);
 418	if (mpls_pkt_too_big(skb, mtu - new_header_size))
 419		goto tx_err;
 420
 421	hh_len = LL_RESERVED_SPACE(out_dev);
 422	if (!out_dev->header_ops)
 423		hh_len = 0;
 424
 425	/* Ensure there is enough space for the headers in the skb */
 426	if (skb_cow(skb, hh_len + new_header_size))
 427		goto tx_err;
 428
 429	skb->dev = out_dev;
 430	skb->protocol = htons(ETH_P_MPLS_UC);
 431
 432	if (unlikely(!new_header_size && dec.bos)) {
 433		/* Penultimate hop popping */
 434		if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
 435			goto err;
 436	} else {
 437		bool bos;
 438		int i;
 439		skb_push(skb, new_header_size);
 440		skb_reset_network_header(skb);
 441		/* Push the new labels */
 442		hdr = mpls_hdr(skb);
 443		bos = dec.bos;
 444		for (i = nh->nh_labels - 1; i >= 0; i--) {
 445			hdr[i] = mpls_entry_encode(nh->nh_label[i],
 446						   dec.ttl, 0, bos);
 447			bos = false;
 448		}
 449	}
 450
 451	mpls_stats_inc_outucastpkts(out_dev, skb);
 452
 453	/* If via wasn't specified then send out using device address */
 454	if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
 455		err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
 456				 out_dev->dev_addr, skb);
 457	else
 458		err = neigh_xmit(nh->nh_via_table, out_dev,
 459				 mpls_nh_via(rt, nh), skb);
 460	if (err)
 461		net_dbg_ratelimited("%s: packet transmission failed: %d\n",
 462				    __func__, err);
 463	return 0;
 464
 465tx_err:
 466	out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
 467	if (out_mdev)
 468		MPLS_INC_STATS(out_mdev, tx_errors);
 469	goto drop;
 470err:
 471	MPLS_INC_STATS(mdev, rx_errors);
 472drop:
 473	kfree_skb(skb);
 474	return NET_RX_DROP;
 475}
 476
 477static struct packet_type mpls_packet_type __read_mostly = {
 478	.type = cpu_to_be16(ETH_P_MPLS_UC),
 479	.func = mpls_forward,
 480};
 481
 482static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
 483	[RTA_DST]		= { .type = NLA_U32 },
 484	[RTA_OIF]		= { .type = NLA_U32 },
 485	[RTA_TTL_PROPAGATE]	= { .type = NLA_U8 },
 486};
 487
 488struct mpls_route_config {
 489	u32			rc_protocol;
 490	u32			rc_ifindex;
 491	u8			rc_via_table;
 492	u8			rc_via_alen;
 493	u8			rc_via[MAX_VIA_ALEN];
 494	u32			rc_label;
 495	u8			rc_ttl_propagate;
 496	u8			rc_output_labels;
 497	u32			rc_output_label[MAX_NEW_LABELS];
 498	u32			rc_nlflags;
 499	enum mpls_payload_type	rc_payload_type;
 500	struct nl_info		rc_nlinfo;
 501	struct rtnexthop	*rc_mp;
 502	int			rc_mp_len;
 503};
 504
 505/* all nexthops within a route have the same size based on max
 506 * number of labels and max via length for a hop
 507 */
 508static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
 509{
 510	u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
 511	struct mpls_route *rt;
 512	size_t size;
 513
 514	size = sizeof(*rt) + num_nh * nh_size;
 515	if (size > MAX_MPLS_ROUTE_MEM)
 516		return ERR_PTR(-EINVAL);
 517
 518	rt = kzalloc(size, GFP_KERNEL);
 519	if (!rt)
 520		return ERR_PTR(-ENOMEM);
 521
 522	rt->rt_nhn = num_nh;
 523	rt->rt_nhn_alive = num_nh;
 524	rt->rt_nh_size = nh_size;
 525	rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
 526
 527	return rt;
 528}
 529
 530static void mpls_rt_free(struct mpls_route *rt)
 531{
 532	if (rt)
 533		kfree_rcu(rt, rt_rcu);
 534}
 535
 536static void mpls_notify_route(struct net *net, unsigned index,
 537			      struct mpls_route *old, struct mpls_route *new,
 538			      const struct nl_info *info)
 539{
 540	struct nlmsghdr *nlh = info ? info->nlh : NULL;
 541	unsigned portid = info ? info->portid : 0;
 542	int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
 543	struct mpls_route *rt = new ? new : old;
 544	unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
 545	/* Ignore reserved labels for now */
 546	if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
 547		rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
 548}
 549
 550static void mpls_route_update(struct net *net, unsigned index,
 551			      struct mpls_route *new,
 552			      const struct nl_info *info)
 553{
 554	struct mpls_route __rcu **platform_label;
 555	struct mpls_route *rt;
 556
 557	ASSERT_RTNL();
 558
 559	platform_label = rtnl_dereference(net->mpls.platform_label);
 560	rt = rtnl_dereference(platform_label[index]);
 561	rcu_assign_pointer(platform_label[index], new);
 562
 563	mpls_notify_route(net, index, rt, new, info);
 564
 565	/* If we removed a route free it now */
 566	mpls_rt_free(rt);
 567}
 568
 569static unsigned find_free_label(struct net *net)
 570{
 571	struct mpls_route __rcu **platform_label;
 572	size_t platform_labels;
 573	unsigned index;
 574
 575	platform_label = rtnl_dereference(net->mpls.platform_label);
 576	platform_labels = net->mpls.platform_labels;
 577	for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
 578	     index++) {
 579		if (!rtnl_dereference(platform_label[index]))
 580			return index;
 581	}
 582	return LABEL_NOT_SPECIFIED;
 583}
 584
 585#if IS_ENABLED(CONFIG_INET)
 586static struct net_device *inet_fib_lookup_dev(struct net *net,
 587					      const void *addr)
 588{
 589	struct net_device *dev;
 590	struct rtable *rt;
 591	struct in_addr daddr;
 592
 593	memcpy(&daddr, addr, sizeof(struct in_addr));
 594	rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
 595	if (IS_ERR(rt))
 596		return ERR_CAST(rt);
 597
 598	dev = rt->dst.dev;
 599	dev_hold(dev);
 600
 601	ip_rt_put(rt);
 602
 603	return dev;
 604}
 605#else
 606static struct net_device *inet_fib_lookup_dev(struct net *net,
 607					      const void *addr)
 608{
 609	return ERR_PTR(-EAFNOSUPPORT);
 610}
 611#endif
 612
 613#if IS_ENABLED(CONFIG_IPV6)
 614static struct net_device *inet6_fib_lookup_dev(struct net *net,
 615					       const void *addr)
 616{
 617	struct net_device *dev;
 618	struct dst_entry *dst;
 619	struct flowi6 fl6;
 620	int err;
 621
 622	if (!ipv6_stub)
 623		return ERR_PTR(-EAFNOSUPPORT);
 624
 625	memset(&fl6, 0, sizeof(fl6));
 626	memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
 627	err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
 628	if (err)
 629		return ERR_PTR(err);
 630
 631	dev = dst->dev;
 632	dev_hold(dev);
 633	dst_release(dst);
 634
 635	return dev;
 636}
 637#else
 638static struct net_device *inet6_fib_lookup_dev(struct net *net,
 639					       const void *addr)
 640{
 641	return ERR_PTR(-EAFNOSUPPORT);
 642}
 643#endif
 644
 645static struct net_device *find_outdev(struct net *net,
 646				      struct mpls_route *rt,
 647				      struct mpls_nh *nh, int oif)
 648{
 649	struct net_device *dev = NULL;
 650
 651	if (!oif) {
 652		switch (nh->nh_via_table) {
 653		case NEIGH_ARP_TABLE:
 654			dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
 655			break;
 656		case NEIGH_ND_TABLE:
 657			dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
 658			break;
 659		case NEIGH_LINK_TABLE:
 660			break;
 661		}
 662	} else {
 663		dev = dev_get_by_index(net, oif);
 664	}
 665
 666	if (!dev)
 667		return ERR_PTR(-ENODEV);
 668
 669	if (IS_ERR(dev))
 670		return dev;
 671
 672	/* The caller is holding rtnl anyways, so release the dev reference */
 673	dev_put(dev);
 674
 675	return dev;
 676}
 677
 678static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
 679			      struct mpls_nh *nh, int oif)
 680{
 681	struct net_device *dev = NULL;
 682	int err = -ENODEV;
 683
 684	dev = find_outdev(net, rt, nh, oif);
 685	if (IS_ERR(dev)) {
 686		err = PTR_ERR(dev);
 687		dev = NULL;
 688		goto errout;
 689	}
 690
 691	/* Ensure this is a supported device */
 692	err = -EINVAL;
 693	if (!mpls_dev_get(dev))
 694		goto errout;
 695
 696	if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
 697	    (dev->addr_len != nh->nh_via_alen))
 698		goto errout;
 699
 700	RCU_INIT_POINTER(nh->nh_dev, dev);
 701
 702	if (!(dev->flags & IFF_UP)) {
 703		nh->nh_flags |= RTNH_F_DEAD;
 704	} else {
 705		unsigned int flags;
 706
 707		flags = dev_get_flags(dev);
 708		if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
 709			nh->nh_flags |= RTNH_F_LINKDOWN;
 710	}
 711
 712	return 0;
 713
 714errout:
 715	return err;
 716}
 717
 718static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
 719		       u8 via_addr[], struct netlink_ext_ack *extack)
 720{
 721	struct rtvia *via = nla_data(nla);
 722	int err = -EINVAL;
 723	int alen;
 724
 725	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
 726		NL_SET_ERR_MSG_ATTR(extack, nla,
 727				    "Invalid attribute length for RTA_VIA");
 728		goto errout;
 729	}
 730	alen = nla_len(nla) -
 731			offsetof(struct rtvia, rtvia_addr);
 732	if (alen > MAX_VIA_ALEN) {
 733		NL_SET_ERR_MSG_ATTR(extack, nla,
 734				    "Invalid address length for RTA_VIA");
 735		goto errout;
 736	}
 737
 738	/* Validate the address family */
 739	switch (via->rtvia_family) {
 740	case AF_PACKET:
 741		*via_table = NEIGH_LINK_TABLE;
 742		break;
 743	case AF_INET:
 744		*via_table = NEIGH_ARP_TABLE;
 745		if (alen != 4)
 746			goto errout;
 747		break;
 748	case AF_INET6:
 749		*via_table = NEIGH_ND_TABLE;
 750		if (alen != 16)
 751			goto errout;
 752		break;
 753	default:
 754		/* Unsupported address family */
 755		goto errout;
 756	}
 757
 758	memcpy(via_addr, via->rtvia_addr, alen);
 759	*via_alen = alen;
 760	err = 0;
 761
 762errout:
 763	return err;
 764}
 765
 766static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
 767				  struct mpls_route *rt)
 768{
 769	struct net *net = cfg->rc_nlinfo.nl_net;
 770	struct mpls_nh *nh = rt->rt_nh;
 771	int err;
 772	int i;
 773
 774	if (!nh)
 775		return -ENOMEM;
 776
 777	nh->nh_labels = cfg->rc_output_labels;
 778	for (i = 0; i < nh->nh_labels; i++)
 779		nh->nh_label[i] = cfg->rc_output_label[i];
 780
 781	nh->nh_via_table = cfg->rc_via_table;
 782	memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
 783	nh->nh_via_alen = cfg->rc_via_alen;
 784
 785	err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
 786	if (err)
 787		goto errout;
 788
 789	if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
 790		rt->rt_nhn_alive--;
 791
 792	return 0;
 793
 794errout:
 795	return err;
 796}
 797
 798static int mpls_nh_build(struct net *net, struct mpls_route *rt,
 799			 struct mpls_nh *nh, int oif, struct nlattr *via,
 800			 struct nlattr *newdst, u8 max_labels,
 801			 struct netlink_ext_ack *extack)
 802{
 803	int err = -ENOMEM;
 804
 805	if (!nh)
 806		goto errout;
 807
 808	if (newdst) {
 809		err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
 810				     nh->nh_label, extack);
 811		if (err)
 812			goto errout;
 813	}
 814
 815	if (via) {
 816		err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
 817				  __mpls_nh_via(rt, nh), extack);
 818		if (err)
 819			goto errout;
 820	} else {
 821		nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
 822	}
 823
 824	err = mpls_nh_assign_dev(net, rt, nh, oif);
 825	if (err)
 826		goto errout;
 827
 828	return 0;
 829
 830errout:
 831	return err;
 832}
 833
 834static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
 835			      u8 cfg_via_alen, u8 *max_via_alen,
 836			      u8 *max_labels)
 837{
 838	int remaining = len;
 839	u8 nhs = 0;
 840
 841	*max_via_alen = 0;
 842	*max_labels = 0;
 843
 844	while (rtnh_ok(rtnh, remaining)) {
 845		struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
 846		int attrlen;
 847		u8 n_labels = 0;
 848
 849		attrlen = rtnh_attrlen(rtnh);
 850		nla = nla_find(attrs, attrlen, RTA_VIA);
 851		if (nla && nla_len(nla) >=
 852		    offsetof(struct rtvia, rtvia_addr)) {
 853			int via_alen = nla_len(nla) -
 854				offsetof(struct rtvia, rtvia_addr);
 855
 856			if (via_alen <= MAX_VIA_ALEN)
 857				*max_via_alen = max_t(u16, *max_via_alen,
 858						      via_alen);
 859		}
 860
 861		nla = nla_find(attrs, attrlen, RTA_NEWDST);
 862		if (nla &&
 863		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
 864				   NULL, NULL) != 0)
 865			return 0;
 866
 867		*max_labels = max_t(u8, *max_labels, n_labels);
 868
 869		/* number of nexthops is tracked by a u8.
 870		 * Check for overflow.
 871		 */
 872		if (nhs == 255)
 873			return 0;
 874		nhs++;
 875
 876		rtnh = rtnh_next(rtnh, &remaining);
 877	}
 878
 879	/* leftover implies invalid nexthop configuration, discard it */
 880	return remaining > 0 ? 0 : nhs;
 881}
 882
 883static int mpls_nh_build_multi(struct mpls_route_config *cfg,
 884			       struct mpls_route *rt, u8 max_labels,
 885			       struct netlink_ext_ack *extack)
 886{
 887	struct rtnexthop *rtnh = cfg->rc_mp;
 888	struct nlattr *nla_via, *nla_newdst;
 889	int remaining = cfg->rc_mp_len;
 890	int err = 0;
 891	u8 nhs = 0;
 892
 893	change_nexthops(rt) {
 894		int attrlen;
 895
 896		nla_via = NULL;
 897		nla_newdst = NULL;
 898
 899		err = -EINVAL;
 900		if (!rtnh_ok(rtnh, remaining))
 901			goto errout;
 902
 903		/* neither weighted multipath nor any flags
 904		 * are supported
 905		 */
 906		if (rtnh->rtnh_hops || rtnh->rtnh_flags)
 907			goto errout;
 908
 909		attrlen = rtnh_attrlen(rtnh);
 910		if (attrlen > 0) {
 911			struct nlattr *attrs = rtnh_attrs(rtnh);
 912
 913			nla_via = nla_find(attrs, attrlen, RTA_VIA);
 914			nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
 915		}
 916
 917		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
 918				    rtnh->rtnh_ifindex, nla_via, nla_newdst,
 919				    max_labels, extack);
 920		if (err)
 921			goto errout;
 922
 923		if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
 924			rt->rt_nhn_alive--;
 925
 926		rtnh = rtnh_next(rtnh, &remaining);
 927		nhs++;
 928	} endfor_nexthops(rt);
 929
 930	rt->rt_nhn = nhs;
 931
 932	return 0;
 933
 934errout:
 935	return err;
 936}
 937
 938static bool mpls_label_ok(struct net *net, unsigned int *index,
 939			  struct netlink_ext_ack *extack)
 940{
 941	bool is_ok = true;
 942
 943	/* Reserved labels may not be set */
 944	if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
 945		NL_SET_ERR_MSG(extack,
 946			       "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
 947		is_ok = false;
 948	}
 949
 950	/* The full 20 bit range may not be supported. */
 951	if (is_ok && *index >= net->mpls.platform_labels) {
 952		NL_SET_ERR_MSG(extack,
 953			       "Label >= configured maximum in platform_labels");
 954		is_ok = false;
 955	}
 956
 957	*index = array_index_nospec(*index, net->mpls.platform_labels);
 958	return is_ok;
 959}
 960
 961static int mpls_route_add(struct mpls_route_config *cfg,
 962			  struct netlink_ext_ack *extack)
 963{
 964	struct mpls_route __rcu **platform_label;
 965	struct net *net = cfg->rc_nlinfo.nl_net;
 966	struct mpls_route *rt, *old;
 967	int err = -EINVAL;
 968	u8 max_via_alen;
 969	unsigned index;
 970	u8 max_labels;
 971	u8 nhs;
 972
 973	index = cfg->rc_label;
 974
 975	/* If a label was not specified during insert pick one */
 976	if ((index == LABEL_NOT_SPECIFIED) &&
 977	    (cfg->rc_nlflags & NLM_F_CREATE)) {
 978		index = find_free_label(net);
 979	}
 980
 981	if (!mpls_label_ok(net, &index, extack))
 982		goto errout;
 983
 984	/* Append makes no sense with mpls */
 985	err = -EOPNOTSUPP;
 986	if (cfg->rc_nlflags & NLM_F_APPEND) {
 987		NL_SET_ERR_MSG(extack, "MPLS does not support route append");
 988		goto errout;
 989	}
 990
 991	err = -EEXIST;
 992	platform_label = rtnl_dereference(net->mpls.platform_label);
 993	old = rtnl_dereference(platform_label[index]);
 994	if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
 995		goto errout;
 996
 997	err = -EEXIST;
 998	if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
 999		goto errout;
1000
1001	err = -ENOENT;
1002	if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1003		goto errout;
1004
1005	err = -EINVAL;
1006	if (cfg->rc_mp) {
1007		nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1008					  cfg->rc_via_alen, &max_via_alen,
1009					  &max_labels);
1010	} else {
1011		max_via_alen = cfg->rc_via_alen;
1012		max_labels = cfg->rc_output_labels;
1013		nhs = 1;
1014	}
1015
1016	if (nhs == 0) {
1017		NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1018		goto errout;
1019	}
1020
1021	err = -ENOMEM;
1022	rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1023	if (IS_ERR(rt)) {
1024		err = PTR_ERR(rt);
1025		goto errout;
1026	}
1027
1028	rt->rt_protocol = cfg->rc_protocol;
1029	rt->rt_payload_type = cfg->rc_payload_type;
1030	rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1031
1032	if (cfg->rc_mp)
1033		err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1034	else
1035		err = mpls_nh_build_from_cfg(cfg, rt);
1036	if (err)
1037		goto freert;
1038
1039	mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1040
1041	return 0;
1042
1043freert:
1044	mpls_rt_free(rt);
1045errout:
1046	return err;
1047}
1048
1049static int mpls_route_del(struct mpls_route_config *cfg,
1050			  struct netlink_ext_ack *extack)
1051{
1052	struct net *net = cfg->rc_nlinfo.nl_net;
1053	unsigned index;
1054	int err = -EINVAL;
1055
1056	index = cfg->rc_label;
1057
1058	if (!mpls_label_ok(net, &index, extack))
1059		goto errout;
1060
1061	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1062
1063	err = 0;
1064errout:
1065	return err;
1066}
1067
1068static void mpls_get_stats(struct mpls_dev *mdev,
1069			   struct mpls_link_stats *stats)
1070{
1071	struct mpls_pcpu_stats *p;
1072	int i;
1073
1074	memset(stats, 0, sizeof(*stats));
1075
1076	for_each_possible_cpu(i) {
1077		struct mpls_link_stats local;
1078		unsigned int start;
1079
1080		p = per_cpu_ptr(mdev->stats, i);
1081		do {
1082			start = u64_stats_fetch_begin(&p->syncp);
1083			local = p->stats;
1084		} while (u64_stats_fetch_retry(&p->syncp, start));
1085
1086		stats->rx_packets	+= local.rx_packets;
1087		stats->rx_bytes		+= local.rx_bytes;
1088		stats->tx_packets	+= local.tx_packets;
1089		stats->tx_bytes		+= local.tx_bytes;
1090		stats->rx_errors	+= local.rx_errors;
1091		stats->tx_errors	+= local.tx_errors;
1092		stats->rx_dropped	+= local.rx_dropped;
1093		stats->tx_dropped	+= local.tx_dropped;
1094		stats->rx_noroute	+= local.rx_noroute;
1095	}
1096}
1097
1098static int mpls_fill_stats_af(struct sk_buff *skb,
1099			      const struct net_device *dev)
1100{
1101	struct mpls_link_stats *stats;
1102	struct mpls_dev *mdev;
1103	struct nlattr *nla;
1104
1105	mdev = mpls_dev_get(dev);
1106	if (!mdev)
1107		return -ENODATA;
1108
1109	nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1110				sizeof(struct mpls_link_stats),
1111				MPLS_STATS_UNSPEC);
1112	if (!nla)
1113		return -EMSGSIZE;
1114
1115	stats = nla_data(nla);
1116	mpls_get_stats(mdev, stats);
1117
1118	return 0;
1119}
1120
1121static size_t mpls_get_stats_af_size(const struct net_device *dev)
1122{
1123	struct mpls_dev *mdev;
1124
1125	mdev = mpls_dev_get(dev);
1126	if (!mdev)
1127		return 0;
1128
1129	return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1130}
1131
1132static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1133				     u32 portid, u32 seq, int event,
1134				     unsigned int flags, int type)
1135{
1136	struct nlmsghdr  *nlh;
1137	struct netconfmsg *ncm;
1138	bool all = false;
1139
1140	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1141			flags);
1142	if (!nlh)
1143		return -EMSGSIZE;
1144
1145	if (type == NETCONFA_ALL)
1146		all = true;
1147
1148	ncm = nlmsg_data(nlh);
1149	ncm->ncm_family = AF_MPLS;
1150
1151	if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1152		goto nla_put_failure;
1153
1154	if ((all || type == NETCONFA_INPUT) &&
1155	    nla_put_s32(skb, NETCONFA_INPUT,
1156			mdev->input_enabled) < 0)
1157		goto nla_put_failure;
1158
1159	nlmsg_end(skb, nlh);
1160	return 0;
1161
1162nla_put_failure:
1163	nlmsg_cancel(skb, nlh);
1164	return -EMSGSIZE;
1165}
1166
1167static int mpls_netconf_msgsize_devconf(int type)
1168{
1169	int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1170			+ nla_total_size(4); /* NETCONFA_IFINDEX */
1171	bool all = false;
1172
1173	if (type == NETCONFA_ALL)
1174		all = true;
1175
1176	if (all || type == NETCONFA_INPUT)
1177		size += nla_total_size(4);
1178
1179	return size;
1180}
1181
1182static void mpls_netconf_notify_devconf(struct net *net, int event,
1183					int type, struct mpls_dev *mdev)
1184{
1185	struct sk_buff *skb;
1186	int err = -ENOBUFS;
1187
1188	skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1189	if (!skb)
1190		goto errout;
1191
1192	err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1193	if (err < 0) {
1194		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1195		WARN_ON(err == -EMSGSIZE);
1196		kfree_skb(skb);
1197		goto errout;
1198	}
1199
1200	rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1201	return;
1202errout:
1203	if (err < 0)
1204		rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1205}
1206
1207static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1208	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
1209};
1210
1211static int mpls_netconf_valid_get_req(struct sk_buff *skb,
1212				      const struct nlmsghdr *nlh,
1213				      struct nlattr **tb,
1214				      struct netlink_ext_ack *extack)
1215{
1216	int i, err;
1217
1218	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
1219		NL_SET_ERR_MSG_MOD(extack,
1220				   "Invalid header for netconf get request");
1221		return -EINVAL;
1222	}
1223
1224	if (!netlink_strict_get_check(skb))
1225		return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
1226					      tb, NETCONFA_MAX,
1227					      devconf_mpls_policy, extack);
1228
1229	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
1230					    tb, NETCONFA_MAX,
1231					    devconf_mpls_policy, extack);
1232	if (err)
1233		return err;
1234
1235	for (i = 0; i <= NETCONFA_MAX; i++) {
1236		if (!tb[i])
1237			continue;
1238
1239		switch (i) {
1240		case NETCONFA_IFINDEX:
1241			break;
1242		default:
1243			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
1244			return -EINVAL;
1245		}
1246	}
1247
1248	return 0;
1249}
1250
1251static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1252				    struct nlmsghdr *nlh,
1253				    struct netlink_ext_ack *extack)
1254{
1255	struct net *net = sock_net(in_skb->sk);
1256	struct nlattr *tb[NETCONFA_MAX + 1];
1257	struct net_device *dev;
1258	struct mpls_dev *mdev;
1259	struct sk_buff *skb;
1260	int ifindex;
1261	int err;
1262
1263	err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
1264	if (err < 0)
1265		goto errout;
1266
1267	err = -EINVAL;
1268	if (!tb[NETCONFA_IFINDEX])
1269		goto errout;
1270
1271	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1272	dev = __dev_get_by_index(net, ifindex);
1273	if (!dev)
1274		goto errout;
1275
1276	mdev = mpls_dev_get(dev);
1277	if (!mdev)
1278		goto errout;
1279
1280	err = -ENOBUFS;
1281	skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1282	if (!skb)
1283		goto errout;
1284
1285	err = mpls_netconf_fill_devconf(skb, mdev,
1286					NETLINK_CB(in_skb).portid,
1287					nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1288					NETCONFA_ALL);
1289	if (err < 0) {
1290		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1291		WARN_ON(err == -EMSGSIZE);
1292		kfree_skb(skb);
1293		goto errout;
1294	}
1295	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1296errout:
1297	return err;
1298}
1299
1300static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1301				     struct netlink_callback *cb)
1302{
1303	const struct nlmsghdr *nlh = cb->nlh;
1304	struct net *net = sock_net(skb->sk);
1305	struct hlist_head *head;
1306	struct net_device *dev;
1307	struct mpls_dev *mdev;
1308	int idx, s_idx;
1309	int h, s_h;
1310
1311	if (cb->strict_check) {
1312		struct netlink_ext_ack *extack = cb->extack;
1313		struct netconfmsg *ncm;
1314
1315		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1316			NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1317			return -EINVAL;
1318		}
1319
1320		if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1321			NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1322			return -EINVAL;
1323		}
1324	}
1325
1326	s_h = cb->args[0];
1327	s_idx = idx = cb->args[1];
1328
1329	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1330		idx = 0;
1331		head = &net->dev_index_head[h];
1332		rcu_read_lock();
1333		cb->seq = net->dev_base_seq;
1334		hlist_for_each_entry_rcu(dev, head, index_hlist) {
1335			if (idx < s_idx)
1336				goto cont;
1337			mdev = mpls_dev_get(dev);
1338			if (!mdev)
1339				goto cont;
1340			if (mpls_netconf_fill_devconf(skb, mdev,
1341						      NETLINK_CB(cb->skb).portid,
1342						      nlh->nlmsg_seq,
1343						      RTM_NEWNETCONF,
1344						      NLM_F_MULTI,
1345						      NETCONFA_ALL) < 0) {
1346				rcu_read_unlock();
1347				goto done;
1348			}
1349			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1350cont:
1351			idx++;
1352		}
1353		rcu_read_unlock();
1354	}
1355done:
1356	cb->args[0] = h;
1357	cb->args[1] = idx;
1358
1359	return skb->len;
1360}
1361
1362#define MPLS_PERDEV_SYSCTL_OFFSET(field)	\
1363	(&((struct mpls_dev *)0)->field)
1364
1365static int mpls_conf_proc(struct ctl_table *ctl, int write,
1366			  void __user *buffer,
1367			  size_t *lenp, loff_t *ppos)
1368{
1369	int oval = *(int *)ctl->data;
1370	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1371
1372	if (write) {
1373		struct mpls_dev *mdev = ctl->extra1;
1374		int i = (int *)ctl->data - (int *)mdev;
1375		struct net *net = ctl->extra2;
1376		int val = *(int *)ctl->data;
1377
1378		if (i == offsetof(struct mpls_dev, input_enabled) &&
1379		    val != oval) {
1380			mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1381						    NETCONFA_INPUT, mdev);
1382		}
1383	}
1384
1385	return ret;
1386}
1387
1388static const struct ctl_table mpls_dev_table[] = {
1389	{
1390		.procname	= "input",
1391		.maxlen		= sizeof(int),
1392		.mode		= 0644,
1393		.proc_handler	= mpls_conf_proc,
1394		.data		= MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1395	},
1396	{ }
1397};
1398
1399static int mpls_dev_sysctl_register(struct net_device *dev,
1400				    struct mpls_dev *mdev)
1401{
1402	char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1403	struct net *net = dev_net(dev);
1404	struct ctl_table *table;
1405	int i;
1406
1407	table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1408	if (!table)
1409		goto out;
1410
1411	/* Table data contains only offsets relative to the base of
1412	 * the mdev at this point, so make them absolute.
1413	 */
1414	for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1415		table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1416		table[i].extra1 = mdev;
1417		table[i].extra2 = net;
1418	}
1419
1420	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1421
1422	mdev->sysctl = register_net_sysctl(net, path, table);
1423	if (!mdev->sysctl)
1424		goto free;
1425
1426	mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1427	return 0;
1428
1429free:
1430	kfree(table);
1431out:
1432	return -ENOBUFS;
1433}
1434
1435static void mpls_dev_sysctl_unregister(struct net_device *dev,
1436				       struct mpls_dev *mdev)
1437{
1438	struct net *net = dev_net(dev);
1439	struct ctl_table *table;
1440
1441	table = mdev->sysctl->ctl_table_arg;
1442	unregister_net_sysctl_table(mdev->sysctl);
1443	kfree(table);
1444
1445	mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1446}
1447
1448static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1449{
1450	struct mpls_dev *mdev;
1451	int err = -ENOMEM;
1452	int i;
1453
1454	ASSERT_RTNL();
1455
1456	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1457	if (!mdev)
1458		return ERR_PTR(err);
1459
1460	mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1461	if (!mdev->stats)
1462		goto free;
1463
1464	for_each_possible_cpu(i) {
1465		struct mpls_pcpu_stats *mpls_stats;
1466
1467		mpls_stats = per_cpu_ptr(mdev->stats, i);
1468		u64_stats_init(&mpls_stats->syncp);
1469	}
1470
1471	mdev->dev = dev;
1472
1473	err = mpls_dev_sysctl_register(dev, mdev);
1474	if (err)
1475		goto free;
1476
1477	rcu_assign_pointer(dev->mpls_ptr, mdev);
1478
1479	return mdev;
1480
1481free:
1482	free_percpu(mdev->stats);
1483	kfree(mdev);
1484	return ERR_PTR(err);
1485}
1486
1487static void mpls_dev_destroy_rcu(struct rcu_head *head)
1488{
1489	struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1490
1491	free_percpu(mdev->stats);
1492	kfree(mdev);
1493}
1494
1495static void mpls_ifdown(struct net_device *dev, int event)
1496{
1497	struct mpls_route __rcu **platform_label;
1498	struct net *net = dev_net(dev);
1499	u8 alive, deleted;
1500	unsigned index;
1501
1502	platform_label = rtnl_dereference(net->mpls.platform_label);
1503	for (index = 0; index < net->mpls.platform_labels; index++) {
1504		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1505
1506		if (!rt)
1507			continue;
1508
1509		alive = 0;
1510		deleted = 0;
1511		change_nexthops(rt) {
1512			unsigned int nh_flags = nh->nh_flags;
1513
1514			if (rtnl_dereference(nh->nh_dev) != dev)
1515				goto next;
1516
1517			switch (event) {
1518			case NETDEV_DOWN:
1519			case NETDEV_UNREGISTER:
1520				nh_flags |= RTNH_F_DEAD;
1521				/* fall through */
1522			case NETDEV_CHANGE:
1523				nh_flags |= RTNH_F_LINKDOWN;
1524				break;
1525			}
1526			if (event == NETDEV_UNREGISTER)
1527				RCU_INIT_POINTER(nh->nh_dev, NULL);
1528
1529			if (nh->nh_flags != nh_flags)
1530				WRITE_ONCE(nh->nh_flags, nh_flags);
1531next:
1532			if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1533				alive++;
1534			if (!rtnl_dereference(nh->nh_dev))
1535				deleted++;
1536		} endfor_nexthops(rt);
1537
1538		WRITE_ONCE(rt->rt_nhn_alive, alive);
1539
1540		/* if there are no more nexthops, delete the route */
1541		if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1542			mpls_route_update(net, index, NULL, NULL);
1543	}
1544}
1545
1546static void mpls_ifup(struct net_device *dev, unsigned int flags)
1547{
1548	struct mpls_route __rcu **platform_label;
1549	struct net *net = dev_net(dev);
1550	unsigned index;
1551	u8 alive;
1552
1553	platform_label = rtnl_dereference(net->mpls.platform_label);
1554	for (index = 0; index < net->mpls.platform_labels; index++) {
1555		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1556
1557		if (!rt)
1558			continue;
1559
1560		alive = 0;
1561		change_nexthops(rt) {
1562			unsigned int nh_flags = nh->nh_flags;
1563			struct net_device *nh_dev =
1564				rtnl_dereference(nh->nh_dev);
1565
1566			if (!(nh_flags & flags)) {
1567				alive++;
1568				continue;
1569			}
1570			if (nh_dev != dev)
1571				continue;
1572			alive++;
1573			nh_flags &= ~flags;
1574			WRITE_ONCE(nh->nh_flags, nh_flags);
1575		} endfor_nexthops(rt);
1576
1577		WRITE_ONCE(rt->rt_nhn_alive, alive);
1578	}
1579}
1580
1581static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1582			   void *ptr)
1583{
1584	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1585	struct mpls_dev *mdev;
1586	unsigned int flags;
1587
1588	if (event == NETDEV_REGISTER) {
1589
1590		/* For now just support Ethernet, IPGRE, IP6GRE, SIT and
1591		 * IPIP devices
1592		 */
1593		if (dev->type == ARPHRD_ETHER ||
1594		    dev->type == ARPHRD_LOOPBACK ||
1595		    dev->type == ARPHRD_IPGRE ||
1596		    dev->type == ARPHRD_IP6GRE ||
1597		    dev->type == ARPHRD_SIT ||
1598		    dev->type == ARPHRD_TUNNEL) {
1599			mdev = mpls_add_dev(dev);
1600			if (IS_ERR(mdev))
1601				return notifier_from_errno(PTR_ERR(mdev));
1602		}
1603		return NOTIFY_OK;
1604	}
1605
1606	mdev = mpls_dev_get(dev);
1607	if (!mdev)
1608		return NOTIFY_OK;
1609
1610	switch (event) {
1611	case NETDEV_DOWN:
1612		mpls_ifdown(dev, event);
1613		break;
1614	case NETDEV_UP:
1615		flags = dev_get_flags(dev);
1616		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1617			mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1618		else
1619			mpls_ifup(dev, RTNH_F_DEAD);
1620		break;
1621	case NETDEV_CHANGE:
1622		flags = dev_get_flags(dev);
1623		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1624			mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1625		else
1626			mpls_ifdown(dev, event);
1627		break;
1628	case NETDEV_UNREGISTER:
1629		mpls_ifdown(dev, event);
1630		mdev = mpls_dev_get(dev);
1631		if (mdev) {
1632			mpls_dev_sysctl_unregister(dev, mdev);
1633			RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1634			call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1635		}
1636		break;
1637	case NETDEV_CHANGENAME:
1638		mdev = mpls_dev_get(dev);
1639		if (mdev) {
1640			int err;
1641
1642			mpls_dev_sysctl_unregister(dev, mdev);
1643			err = mpls_dev_sysctl_register(dev, mdev);
1644			if (err)
1645				return notifier_from_errno(err);
1646		}
1647		break;
1648	}
1649	return NOTIFY_OK;
1650}
1651
1652static struct notifier_block mpls_dev_notifier = {
1653	.notifier_call = mpls_dev_notify,
1654};
1655
1656static int nla_put_via(struct sk_buff *skb,
1657		       u8 table, const void *addr, int alen)
1658{
1659	static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1660		AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1661	};
1662	struct nlattr *nla;
1663	struct rtvia *via;
1664	int family = AF_UNSPEC;
1665
1666	nla = nla_reserve(skb, RTA_VIA, alen + 2);
1667	if (!nla)
1668		return -EMSGSIZE;
1669
1670	if (table <= NEIGH_NR_TABLES)
1671		family = table_to_family[table];
1672
1673	via = nla_data(nla);
1674	via->rtvia_family = family;
1675	memcpy(via->rtvia_addr, addr, alen);
1676	return 0;
1677}
1678
1679int nla_put_labels(struct sk_buff *skb, int attrtype,
1680		   u8 labels, const u32 label[])
1681{
1682	struct nlattr *nla;
1683	struct mpls_shim_hdr *nla_label;
1684	bool bos;
1685	int i;
1686	nla = nla_reserve(skb, attrtype, labels*4);
1687	if (!nla)
1688		return -EMSGSIZE;
1689
1690	nla_label = nla_data(nla);
1691	bos = true;
1692	for (i = labels - 1; i >= 0; i--) {
1693		nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1694		bos = false;
1695	}
1696
1697	return 0;
1698}
1699EXPORT_SYMBOL_GPL(nla_put_labels);
1700
1701int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1702		   u32 label[], struct netlink_ext_ack *extack)
1703{
1704	unsigned len = nla_len(nla);
1705	struct mpls_shim_hdr *nla_label;
1706	u8 nla_labels;
1707	bool bos;
1708	int i;
1709
1710	/* len needs to be an even multiple of 4 (the label size). Number
1711	 * of labels is a u8 so check for overflow.
1712	 */
1713	if (len & 3 || len / 4 > 255) {
1714		NL_SET_ERR_MSG_ATTR(extack, nla,
1715				    "Invalid length for labels attribute");
1716		return -EINVAL;
1717	}
1718
1719	/* Limit the number of new labels allowed */
1720	nla_labels = len/4;
1721	if (nla_labels > max_labels) {
1722		NL_SET_ERR_MSG(extack, "Too many labels");
1723		return -EINVAL;
1724	}
1725
1726	/* when label == NULL, caller wants number of labels */
1727	if (!label)
1728		goto out;
1729
1730	nla_label = nla_data(nla);
1731	bos = true;
1732	for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1733		struct mpls_entry_decoded dec;
1734		dec = mpls_entry_decode(nla_label + i);
1735
1736		/* Ensure the bottom of stack flag is properly set
1737		 * and ttl and tc are both clear.
1738		 */
1739		if (dec.ttl) {
1740			NL_SET_ERR_MSG_ATTR(extack, nla,
1741					    "TTL in label must be 0");
1742			return -EINVAL;
1743		}
1744
1745		if (dec.tc) {
1746			NL_SET_ERR_MSG_ATTR(extack, nla,
1747					    "Traffic class in label must be 0");
1748			return -EINVAL;
1749		}
1750
1751		if (dec.bos != bos) {
1752			NL_SET_BAD_ATTR(extack, nla);
1753			if (bos) {
1754				NL_SET_ERR_MSG(extack,
1755					       "BOS bit must be set in first label");
1756			} else {
1757				NL_SET_ERR_MSG(extack,
1758					       "BOS bit can only be set in first label");
1759			}
1760			return -EINVAL;
1761		}
1762
1763		switch (dec.label) {
1764		case MPLS_LABEL_IMPLNULL:
1765			/* RFC3032: This is a label that an LSR may
1766			 * assign and distribute, but which never
1767			 * actually appears in the encapsulation.
1768			 */
1769			NL_SET_ERR_MSG_ATTR(extack, nla,
1770					    "Implicit NULL Label (3) can not be used in encapsulation");
1771			return -EINVAL;
1772		}
1773
1774		label[i] = dec.label;
1775	}
1776out:
1777	*labels = nla_labels;
1778	return 0;
1779}
1780EXPORT_SYMBOL_GPL(nla_get_labels);
1781
1782static int rtm_to_route_config(struct sk_buff *skb,
1783			       struct nlmsghdr *nlh,
1784			       struct mpls_route_config *cfg,
1785			       struct netlink_ext_ack *extack)
1786{
1787	struct rtmsg *rtm;
1788	struct nlattr *tb[RTA_MAX+1];
1789	int index;
1790	int err;
1791
1792	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1793				     rtm_mpls_policy, extack);
1794	if (err < 0)
1795		goto errout;
1796
1797	err = -EINVAL;
1798	rtm = nlmsg_data(nlh);
1799
1800	if (rtm->rtm_family != AF_MPLS) {
1801		NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1802		goto errout;
1803	}
1804	if (rtm->rtm_dst_len != 20) {
1805		NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1806		goto errout;
1807	}
1808	if (rtm->rtm_src_len != 0) {
1809		NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1810		goto errout;
1811	}
1812	if (rtm->rtm_tos != 0) {
1813		NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1814		goto errout;
1815	}
1816	if (rtm->rtm_table != RT_TABLE_MAIN) {
1817		NL_SET_ERR_MSG(extack,
1818			       "MPLS only supports the main route table");
1819		goto errout;
1820	}
1821	/* Any value is acceptable for rtm_protocol */
1822
1823	/* As mpls uses destination specific addresses
1824	 * (or source specific address in the case of multicast)
1825	 * all addresses have universal scope.
1826	 */
1827	if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1828		NL_SET_ERR_MSG(extack,
1829			       "Invalid route scope  - MPLS only supports UNIVERSE");
1830		goto errout;
1831	}
1832	if (rtm->rtm_type != RTN_UNICAST) {
1833		NL_SET_ERR_MSG(extack,
1834			       "Invalid route type - MPLS only supports UNICAST");
1835		goto errout;
1836	}
1837	if (rtm->rtm_flags != 0) {
1838		NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1839		goto errout;
1840	}
1841
1842	cfg->rc_label		= LABEL_NOT_SPECIFIED;
1843	cfg->rc_protocol	= rtm->rtm_protocol;
1844	cfg->rc_via_table	= MPLS_NEIGH_TABLE_UNSPEC;
1845	cfg->rc_ttl_propagate	= MPLS_TTL_PROP_DEFAULT;
1846	cfg->rc_nlflags		= nlh->nlmsg_flags;
1847	cfg->rc_nlinfo.portid	= NETLINK_CB(skb).portid;
1848	cfg->rc_nlinfo.nlh	= nlh;
1849	cfg->rc_nlinfo.nl_net	= sock_net(skb->sk);
1850
1851	for (index = 0; index <= RTA_MAX; index++) {
1852		struct nlattr *nla = tb[index];
1853		if (!nla)
1854			continue;
1855
1856		switch (index) {
1857		case RTA_OIF:
1858			cfg->rc_ifindex = nla_get_u32(nla);
1859			break;
1860		case RTA_NEWDST:
1861			if (nla_get_labels(nla, MAX_NEW_LABELS,
1862					   &cfg->rc_output_labels,
1863					   cfg->rc_output_label, extack))
1864				goto errout;
1865			break;
1866		case RTA_DST:
1867		{
1868			u8 label_count;
1869			if (nla_get_labels(nla, 1, &label_count,
1870					   &cfg->rc_label, extack))
1871				goto errout;
1872
1873			if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1874					   &cfg->rc_label, extack))
1875				goto errout;
1876			break;
1877		}
1878		case RTA_GATEWAY:
1879			NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1880			goto errout;
1881		case RTA_VIA:
1882		{
1883			if (nla_get_via(nla, &cfg->rc_via_alen,
1884					&cfg->rc_via_table, cfg->rc_via,
1885					extack))
1886				goto errout;
1887			break;
1888		}
1889		case RTA_MULTIPATH:
1890		{
1891			cfg->rc_mp = nla_data(nla);
1892			cfg->rc_mp_len = nla_len(nla);
1893			break;
1894		}
1895		case RTA_TTL_PROPAGATE:
1896		{
1897			u8 ttl_propagate = nla_get_u8(nla);
1898
1899			if (ttl_propagate > 1) {
1900				NL_SET_ERR_MSG_ATTR(extack, nla,
1901						    "RTA_TTL_PROPAGATE can only be 0 or 1");
1902				goto errout;
1903			}
1904			cfg->rc_ttl_propagate = ttl_propagate ?
1905				MPLS_TTL_PROP_ENABLED :
1906				MPLS_TTL_PROP_DISABLED;
1907			break;
1908		}
1909		default:
1910			NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1911			/* Unsupported attribute */
1912			goto errout;
1913		}
1914	}
1915
1916	err = 0;
1917errout:
1918	return err;
1919}
1920
1921static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1922			     struct netlink_ext_ack *extack)
1923{
1924	struct mpls_route_config *cfg;
1925	int err;
1926
1927	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1928	if (!cfg)
1929		return -ENOMEM;
1930
1931	err = rtm_to_route_config(skb, nlh, cfg, extack);
1932	if (err < 0)
1933		goto out;
1934
1935	err = mpls_route_del(cfg, extack);
1936out:
1937	kfree(cfg);
1938
1939	return err;
1940}
1941
1942
1943static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1944			     struct netlink_ext_ack *extack)
1945{
1946	struct mpls_route_config *cfg;
1947	int err;
1948
1949	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1950	if (!cfg)
1951		return -ENOMEM;
1952
1953	err = rtm_to_route_config(skb, nlh, cfg, extack);
1954	if (err < 0)
1955		goto out;
1956
1957	err = mpls_route_add(cfg, extack);
1958out:
1959	kfree(cfg);
1960
1961	return err;
1962}
1963
1964static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1965			   u32 label, struct mpls_route *rt, int flags)
1966{
1967	struct net_device *dev;
1968	struct nlmsghdr *nlh;
1969	struct rtmsg *rtm;
1970
1971	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1972	if (nlh == NULL)
1973		return -EMSGSIZE;
1974
1975	rtm = nlmsg_data(nlh);
1976	rtm->rtm_family = AF_MPLS;
1977	rtm->rtm_dst_len = 20;
1978	rtm->rtm_src_len = 0;
1979	rtm->rtm_tos = 0;
1980	rtm->rtm_table = RT_TABLE_MAIN;
1981	rtm->rtm_protocol = rt->rt_protocol;
1982	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1983	rtm->rtm_type = RTN_UNICAST;
1984	rtm->rtm_flags = 0;
1985
1986	if (nla_put_labels(skb, RTA_DST, 1, &label))
1987		goto nla_put_failure;
1988
1989	if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1990		bool ttl_propagate =
1991			rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1992
1993		if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1994			       ttl_propagate))
1995			goto nla_put_failure;
1996	}
1997	if (rt->rt_nhn == 1) {
1998		const struct mpls_nh *nh = rt->rt_nh;
1999
2000		if (nh->nh_labels &&
2001		    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2002				   nh->nh_label))
2003			goto nla_put_failure;
2004		if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2005		    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2006				nh->nh_via_alen))
2007			goto nla_put_failure;
2008		dev = rtnl_dereference(nh->nh_dev);
2009		if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2010			goto nla_put_failure;
2011		if (nh->nh_flags & RTNH_F_LINKDOWN)
2012			rtm->rtm_flags |= RTNH_F_LINKDOWN;
2013		if (nh->nh_flags & RTNH_F_DEAD)
2014			rtm->rtm_flags |= RTNH_F_DEAD;
2015	} else {
2016		struct rtnexthop *rtnh;
2017		struct nlattr *mp;
2018		u8 linkdown = 0;
2019		u8 dead = 0;
2020
2021		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2022		if (!mp)
2023			goto nla_put_failure;
2024
2025		for_nexthops(rt) {
2026			dev = rtnl_dereference(nh->nh_dev);
2027			if (!dev)
2028				continue;
2029
2030			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2031			if (!rtnh)
2032				goto nla_put_failure;
2033
2034			rtnh->rtnh_ifindex = dev->ifindex;
2035			if (nh->nh_flags & RTNH_F_LINKDOWN) {
2036				rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2037				linkdown++;
2038			}
2039			if (nh->nh_flags & RTNH_F_DEAD) {
2040				rtnh->rtnh_flags |= RTNH_F_DEAD;
2041				dead++;
2042			}
2043
2044			if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2045							    nh->nh_labels,
2046							    nh->nh_label))
2047				goto nla_put_failure;
2048			if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2049			    nla_put_via(skb, nh->nh_via_table,
2050					mpls_nh_via(rt, nh),
2051					nh->nh_via_alen))
2052				goto nla_put_failure;
2053
2054			/* length of rtnetlink header + attributes */
2055			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2056		} endfor_nexthops(rt);
2057
2058		if (linkdown == rt->rt_nhn)
2059			rtm->rtm_flags |= RTNH_F_LINKDOWN;
2060		if (dead == rt->rt_nhn)
2061			rtm->rtm_flags |= RTNH_F_DEAD;
2062
2063		nla_nest_end(skb, mp);
2064	}
2065
2066	nlmsg_end(skb, nlh);
2067	return 0;
2068
2069nla_put_failure:
2070	nlmsg_cancel(skb, nlh);
2071	return -EMSGSIZE;
2072}
2073
2074#if IS_ENABLED(CONFIG_INET)
2075static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2076				   struct fib_dump_filter *filter,
2077				   struct netlink_callback *cb)
2078{
2079	return ip_valid_fib_dump_req(net, nlh, filter, cb);
2080}
2081#else
2082static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2083				   struct fib_dump_filter *filter,
2084				   struct netlink_callback *cb)
2085{
2086	struct netlink_ext_ack *extack = cb->extack;
2087	struct nlattr *tb[RTA_MAX + 1];
2088	struct rtmsg *rtm;
2089	int err, i;
2090
2091	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2092		NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2093		return -EINVAL;
2094	}
2095
2096	rtm = nlmsg_data(nlh);
2097	if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
2098	    rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
2099	    rtm->rtm_flags) {
2100		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2101		return -EINVAL;
2102	}
2103
2104	if (rtm->rtm_protocol) {
2105		filter->protocol = rtm->rtm_protocol;
2106		filter->filter_set = 1;
2107		cb->answer_flags = NLM_F_DUMP_FILTERED;
2108	}
2109
2110	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2111					    rtm_mpls_policy, extack);
2112	if (err < 0)
2113		return err;
2114
2115	for (i = 0; i <= RTA_MAX; ++i) {
2116		int ifindex;
2117
2118		if (i == RTA_OIF) {
2119			ifindex = nla_get_u32(tb[i]);
2120			filter->dev = __dev_get_by_index(net, ifindex);
2121			if (!filter->dev)
2122				return -ENODEV;
2123			filter->filter_set = 1;
2124		} else if (tb[i]) {
2125			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2126			return -EINVAL;
2127		}
2128	}
2129
2130	return 0;
2131}
2132#endif
2133
2134static bool mpls_rt_uses_dev(struct mpls_route *rt,
2135			     const struct net_device *dev)
2136{
2137	struct net_device *nh_dev;
2138
2139	if (rt->rt_nhn == 1) {
2140		struct mpls_nh *nh = rt->rt_nh;
2141
2142		nh_dev = rtnl_dereference(nh->nh_dev);
2143		if (dev == nh_dev)
2144			return true;
2145	} else {
2146		for_nexthops(rt) {
2147			nh_dev = rtnl_dereference(nh->nh_dev);
2148			if (nh_dev == dev)
2149				return true;
2150		} endfor_nexthops(rt);
2151	}
2152
2153	return false;
2154}
2155
2156static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2157{
2158	const struct nlmsghdr *nlh = cb->nlh;
2159	struct net *net = sock_net(skb->sk);
2160	struct mpls_route __rcu **platform_label;
2161	struct fib_dump_filter filter = {};
2162	unsigned int flags = NLM_F_MULTI;
2163	size_t platform_labels;
2164	unsigned int index;
2165
2166	ASSERT_RTNL();
2167
2168	if (cb->strict_check) {
2169		int err;
2170
2171		err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2172		if (err < 0)
2173			return err;
2174
2175		/* for MPLS, there is only 1 table with fixed type and flags.
2176		 * If either are set in the filter then return nothing.
2177		 */
2178		if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2179		    (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2180		     filter.flags)
2181			return skb->len;
2182	}
2183
2184	index = cb->args[0];
2185	if (index < MPLS_LABEL_FIRST_UNRESERVED)
2186		index = MPLS_LABEL_FIRST_UNRESERVED;
2187
2188	platform_label = rtnl_dereference(net->mpls.platform_label);
2189	platform_labels = net->mpls.platform_labels;
2190
2191	if (filter.filter_set)
2192		flags |= NLM_F_DUMP_FILTERED;
2193
2194	for (; index < platform_labels; index++) {
2195		struct mpls_route *rt;
2196
2197		rt = rtnl_dereference(platform_label[index]);
2198		if (!rt)
2199			continue;
2200
2201		if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2202		    (filter.protocol && rt->rt_protocol != filter.protocol))
2203			continue;
2204
2205		if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2206				    cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2207				    index, rt, flags) < 0)
2208			break;
2209	}
2210	cb->args[0] = index;
2211
2212	return skb->len;
2213}
2214
2215static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2216{
2217	size_t payload =
2218		NLMSG_ALIGN(sizeof(struct rtmsg))
2219		+ nla_total_size(4)			/* RTA_DST */
2220		+ nla_total_size(1);			/* RTA_TTL_PROPAGATE */
2221
2222	if (rt->rt_nhn == 1) {
2223		struct mpls_nh *nh = rt->rt_nh;
2224
2225		if (nh->nh_dev)
2226			payload += nla_total_size(4); /* RTA_OIF */
2227		if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2228			payload += nla_total_size(2 + nh->nh_via_alen);
2229		if (nh->nh_labels) /* RTA_NEWDST */
2230			payload += nla_total_size(nh->nh_labels * 4);
2231	} else {
2232		/* each nexthop is packed in an attribute */
2233		size_t nhsize = 0;
2234
2235		for_nexthops(rt) {
2236			if (!rtnl_dereference(nh->nh_dev))
2237				continue;
2238			nhsize += nla_total_size(sizeof(struct rtnexthop));
2239			/* RTA_VIA */
2240			if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2241				nhsize += nla_total_size(2 + nh->nh_via_alen);
2242			if (nh->nh_labels)
2243				nhsize += nla_total_size(nh->nh_labels * 4);
2244		} endfor_nexthops(rt);
2245		/* nested attribute */
2246		payload += nla_total_size(nhsize);
2247	}
2248
2249	return payload;
2250}
2251
2252static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2253		       struct nlmsghdr *nlh, struct net *net, u32 portid,
2254		       unsigned int nlm_flags)
2255{
2256	struct sk_buff *skb;
2257	u32 seq = nlh ? nlh->nlmsg_seq : 0;
2258	int err = -ENOBUFS;
2259
2260	skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2261	if (skb == NULL)
2262		goto errout;
2263
2264	err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2265	if (err < 0) {
2266		/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2267		WARN_ON(err == -EMSGSIZE);
2268		kfree_skb(skb);
2269		goto errout;
2270	}
2271	rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2272
2273	return;
2274errout:
2275	if (err < 0)
2276		rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2277}
2278
2279static int mpls_valid_getroute_req(struct sk_buff *skb,
2280				   const struct nlmsghdr *nlh,
2281				   struct nlattr **tb,
2282				   struct netlink_ext_ack *extack)
2283{
2284	struct rtmsg *rtm;
2285	int i, err;
2286
2287	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2288		NL_SET_ERR_MSG_MOD(extack,
2289				   "Invalid header for get route request");
2290		return -EINVAL;
2291	}
2292
2293	if (!netlink_strict_get_check(skb))
2294		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2295					      rtm_mpls_policy, extack);
2296
2297	rtm = nlmsg_data(nlh);
2298	if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2299	    rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2300	    rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2301		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2302		return -EINVAL;
2303	}
2304	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2305		NL_SET_ERR_MSG_MOD(extack,
2306				   "Invalid flags for get route request");
2307		return -EINVAL;
2308	}
2309
2310	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2311					    rtm_mpls_policy, extack);
2312	if (err)
2313		return err;
2314
2315	if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2316		NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2317		return -EINVAL;
2318	}
2319
2320	for (i = 0; i <= RTA_MAX; i++) {
2321		if (!tb[i])
2322			continue;
2323
2324		switch (i) {
2325		case RTA_DST:
2326		case RTA_NEWDST:
2327			break;
2328		default:
2329			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2330			return -EINVAL;
2331		}
2332	}
2333
2334	return 0;
2335}
2336
2337static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2338			 struct netlink_ext_ack *extack)
2339{
2340	struct net *net = sock_net(in_skb->sk);
2341	u32 portid = NETLINK_CB(in_skb).portid;
2342	u32 in_label = LABEL_NOT_SPECIFIED;
2343	struct nlattr *tb[RTA_MAX + 1];
2344	u32 labels[MAX_NEW_LABELS];
2345	struct mpls_shim_hdr *hdr;
2346	unsigned int hdr_size = 0;
2347	struct net_device *dev;
2348	struct mpls_route *rt;
2349	struct rtmsg *rtm, *r;
2350	struct nlmsghdr *nlh;
2351	struct sk_buff *skb;
2352	struct mpls_nh *nh;
2353	u8 n_labels;
2354	int err;
2355
2356	err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2357	if (err < 0)
2358		goto errout;
2359
2360	rtm = nlmsg_data(in_nlh);
2361
2362	if (tb[RTA_DST]) {
2363		u8 label_count;
2364
2365		if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2366				   &in_label, extack)) {
2367			err = -EINVAL;
2368			goto errout;
2369		}
2370
2371		if (!mpls_label_ok(net, &in_label, extack)) {
2372			err = -EINVAL;
2373			goto errout;
2374		}
2375	}
2376
2377	rt = mpls_route_input_rcu(net, in_label);
2378	if (!rt) {
2379		err = -ENETUNREACH;
2380		goto errout;
2381	}
2382
2383	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2384		skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2385		if (!skb) {
2386			err = -ENOBUFS;
2387			goto errout;
2388		}
2389
2390		err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2391				      RTM_NEWROUTE, in_label, rt, 0);
2392		if (err < 0) {
2393			/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2394			WARN_ON(err == -EMSGSIZE);
2395			goto errout_free;
2396		}
2397
2398		return rtnl_unicast(skb, net, portid);
2399	}
2400
2401	if (tb[RTA_NEWDST]) {
2402		if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2403				   labels, extack) != 0) {
2404			err = -EINVAL;
2405			goto errout;
2406		}
2407
2408		hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2409	}
2410
2411	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2412	if (!skb) {
2413		err = -ENOBUFS;
2414		goto errout;
2415	}
2416
2417	skb->protocol = htons(ETH_P_MPLS_UC);
2418
2419	if (hdr_size) {
2420		bool bos;
2421		int i;
2422
2423		if (skb_cow(skb, hdr_size)) {
2424			err = -ENOBUFS;
2425			goto errout_free;
2426		}
2427
2428		skb_reserve(skb, hdr_size);
2429		skb_push(skb, hdr_size);
2430		skb_reset_network_header(skb);
2431
2432		/* Push new labels */
2433		hdr = mpls_hdr(skb);
2434		bos = true;
2435		for (i = n_labels - 1; i >= 0; i--) {
2436			hdr[i] = mpls_entry_encode(labels[i],
2437						   1, 0, bos);
2438			bos = false;
2439		}
2440	}
2441
2442	nh = mpls_select_multipath(rt, skb);
2443	if (!nh) {
2444		err = -ENETUNREACH;
2445		goto errout_free;
2446	}
2447
2448	if (hdr_size) {
2449		skb_pull(skb, hdr_size);
2450		skb_reset_network_header(skb);
2451	}
2452
2453	nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2454			RTM_NEWROUTE, sizeof(*r), 0);
2455	if (!nlh) {
2456		err = -EMSGSIZE;
2457		goto errout_free;
2458	}
2459
2460	r = nlmsg_data(nlh);
2461	r->rtm_family	 = AF_MPLS;
2462	r->rtm_dst_len	= 20;
2463	r->rtm_src_len	= 0;
2464	r->rtm_table	= RT_TABLE_MAIN;
2465	r->rtm_type	= RTN_UNICAST;
2466	r->rtm_scope	= RT_SCOPE_UNIVERSE;
2467	r->rtm_protocol = rt->rt_protocol;
2468	r->rtm_flags	= 0;
2469
2470	if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2471		goto nla_put_failure;
2472
2473	if (nh->nh_labels &&
2474	    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2475			   nh->nh_label))
2476		goto nla_put_failure;
2477
2478	if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2479	    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2480			nh->nh_via_alen))
2481		goto nla_put_failure;
2482	dev = rtnl_dereference(nh->nh_dev);
2483	if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2484		goto nla_put_failure;
2485
2486	nlmsg_end(skb, nlh);
2487
2488	err = rtnl_unicast(skb, net, portid);
2489errout:
2490	return err;
2491
2492nla_put_failure:
2493	nlmsg_cancel(skb, nlh);
2494	err = -EMSGSIZE;
2495errout_free:
2496	kfree_skb(skb);
2497	return err;
2498}
2499
2500static int resize_platform_label_table(struct net *net, size_t limit)
2501{
2502	size_t size = sizeof(struct mpls_route *) * limit;
2503	size_t old_limit;
2504	size_t cp_size;
2505	struct mpls_route __rcu **labels = NULL, **old;
2506	struct mpls_route *rt0 = NULL, *rt2 = NULL;
2507	unsigned index;
2508
2509	if (size) {
2510		labels = kvzalloc(size, GFP_KERNEL);
2511		if (!labels)
2512			goto nolabels;
2513	}
2514
2515	/* In case the predefined labels need to be populated */
2516	if (limit > MPLS_LABEL_IPV4NULL) {
2517		struct net_device *lo = net->loopback_dev;
2518		rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2519		if (IS_ERR(rt0))
2520			goto nort0;
2521		RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2522		rt0->rt_protocol = RTPROT_KERNEL;
2523		rt0->rt_payload_type = MPT_IPV4;
2524		rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2525		rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2526		rt0->rt_nh->nh_via_alen = lo->addr_len;
2527		memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2528		       lo->addr_len);
2529	}
2530	if (limit > MPLS_LABEL_IPV6NULL) {
2531		struct net_device *lo = net->loopback_dev;
2532		rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2533		if (IS_ERR(rt2))
2534			goto nort2;
2535		RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2536		rt2->rt_protocol = RTPROT_KERNEL;
2537		rt2->rt_payload_type = MPT_IPV6;
2538		rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2539		rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2540		rt2->rt_nh->nh_via_alen = lo->addr_len;
2541		memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2542		       lo->addr_len);
2543	}
2544
2545	rtnl_lock();
2546	/* Remember the original table */
2547	old = rtnl_dereference(net->mpls.platform_label);
2548	old_limit = net->mpls.platform_labels;
2549
2550	/* Free any labels beyond the new table */
2551	for (index = limit; index < old_limit; index++)
2552		mpls_route_update(net, index, NULL, NULL);
2553
2554	/* Copy over the old labels */
2555	cp_size = size;
2556	if (old_limit < limit)
2557		cp_size = old_limit * sizeof(struct mpls_route *);
2558
2559	memcpy(labels, old, cp_size);
2560
2561	/* If needed set the predefined labels */
2562	if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2563	    (limit > MPLS_LABEL_IPV6NULL)) {
2564		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2565		rt2 = NULL;
2566	}
2567
2568	if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2569	    (limit > MPLS_LABEL_IPV4NULL)) {
2570		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2571		rt0 = NULL;
2572	}
2573
2574	/* Update the global pointers */
2575	net->mpls.platform_labels = limit;
2576	rcu_assign_pointer(net->mpls.platform_label, labels);
2577
2578	rtnl_unlock();
2579
2580	mpls_rt_free(rt2);
2581	mpls_rt_free(rt0);
2582
2583	if (old) {
2584		synchronize_rcu();
2585		kvfree(old);
2586	}
2587	return 0;
2588
2589nort2:
2590	mpls_rt_free(rt0);
2591nort0:
2592	kvfree(labels);
2593nolabels:
2594	return -ENOMEM;
2595}
2596
2597static int mpls_platform_labels(struct ctl_table *table, int write,
2598				void __user *buffer, size_t *lenp, loff_t *ppos)
2599{
2600	struct net *net = table->data;
2601	int platform_labels = net->mpls.platform_labels;
2602	int ret;
2603	struct ctl_table tmp = {
2604		.procname	= table->procname,
2605		.data		= &platform_labels,
2606		.maxlen		= sizeof(int),
2607		.mode		= table->mode,
2608		.extra1		= SYSCTL_ZERO,
2609		.extra2		= &label_limit,
2610	};
2611
2612	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2613
2614	if (write && ret == 0)
2615		ret = resize_platform_label_table(net, platform_labels);
2616
2617	return ret;
2618}
2619
2620#define MPLS_NS_SYSCTL_OFFSET(field)		\
2621	(&((struct net *)0)->field)
2622
2623static const struct ctl_table mpls_table[] = {
2624	{
2625		.procname	= "platform_labels",
2626		.data		= NULL,
2627		.maxlen		= sizeof(int),
2628		.mode		= 0644,
2629		.proc_handler	= mpls_platform_labels,
2630	},
2631	{
2632		.procname	= "ip_ttl_propagate",
2633		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2634		.maxlen		= sizeof(int),
2635		.mode		= 0644,
2636		.proc_handler	= proc_dointvec_minmax,
2637		.extra1		= SYSCTL_ZERO,
2638		.extra2		= SYSCTL_ONE,
2639	},
2640	{
2641		.procname	= "default_ttl",
2642		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2643		.maxlen		= sizeof(int),
2644		.mode		= 0644,
2645		.proc_handler	= proc_dointvec_minmax,
2646		.extra1		= SYSCTL_ONE,
2647		.extra2		= &ttl_max,
2648	},
2649	{ }
2650};
2651
2652static int mpls_net_init(struct net *net)
2653{
2654	struct ctl_table *table;
2655	int i;
2656
2657	net->mpls.platform_labels = 0;
2658	net->mpls.platform_label = NULL;
2659	net->mpls.ip_ttl_propagate = 1;
2660	net->mpls.default_ttl = 255;
2661
2662	table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2663	if (table == NULL)
2664		return -ENOMEM;
2665
2666	/* Table data contains only offsets relative to the base of
2667	 * the mdev at this point, so make them absolute.
2668	 */
2669	for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2670		table[i].data = (char *)net + (uintptr_t)table[i].data;
2671
2672	net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2673	if (net->mpls.ctl == NULL) {
2674		kfree(table);
2675		return -ENOMEM;
2676	}
2677
2678	return 0;
2679}
2680
2681static void mpls_net_exit(struct net *net)
2682{
2683	struct mpls_route __rcu **platform_label;
2684	size_t platform_labels;
2685	struct ctl_table *table;
2686	unsigned int index;
2687
2688	table = net->mpls.ctl->ctl_table_arg;
2689	unregister_net_sysctl_table(net->mpls.ctl);
2690	kfree(table);
2691
2692	/* An rcu grace period has passed since there was a device in
2693	 * the network namespace (and thus the last in flight packet)
2694	 * left this network namespace.  This is because
2695	 * unregister_netdevice_many and netdev_run_todo has completed
2696	 * for each network device that was in this network namespace.
2697	 *
2698	 * As such no additional rcu synchronization is necessary when
2699	 * freeing the platform_label table.
2700	 */
2701	rtnl_lock();
2702	platform_label = rtnl_dereference(net->mpls.platform_label);
2703	platform_labels = net->mpls.platform_labels;
2704	for (index = 0; index < platform_labels; index++) {
2705		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2706		RCU_INIT_POINTER(platform_label[index], NULL);
2707		mpls_notify_route(net, index, rt, NULL, NULL);
2708		mpls_rt_free(rt);
2709	}
2710	rtnl_unlock();
2711
2712	kvfree(platform_label);
2713}
2714
2715static struct pernet_operations mpls_net_ops = {
2716	.init = mpls_net_init,
2717	.exit = mpls_net_exit,
2718};
2719
2720static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2721	.family		   = AF_MPLS,
2722	.fill_stats_af	   = mpls_fill_stats_af,
2723	.get_stats_af_size = mpls_get_stats_af_size,
2724};
2725
2726static int __init mpls_init(void)
2727{
2728	int err;
2729
2730	BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2731
2732	err = register_pernet_subsys(&mpls_net_ops);
2733	if (err)
2734		goto out;
2735
2736	err = register_netdevice_notifier(&mpls_dev_notifier);
2737	if (err)
2738		goto out_unregister_pernet;
2739
2740	dev_add_pack(&mpls_packet_type);
2741
2742	rtnl_af_register(&mpls_af_ops);
2743
2744	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
2745			     mpls_rtm_newroute, NULL, 0);
2746	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
2747			     mpls_rtm_delroute, NULL, 0);
2748	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
2749			     mpls_getroute, mpls_dump_routes, 0);
2750	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2751			     mpls_netconf_get_devconf,
2752			     mpls_netconf_dump_devconf, 0);
2753	err = ipgre_tunnel_encap_add_mpls_ops();
2754	if (err)
2755		pr_err("Can't add mpls over gre tunnel ops\n");
2756
2757	err = 0;
2758out:
2759	return err;
2760
2761out_unregister_pernet:
2762	unregister_pernet_subsys(&mpls_net_ops);
2763	goto out;
2764}
2765module_init(mpls_init);
2766
2767static void __exit mpls_exit(void)
2768{
2769	rtnl_unregister_all(PF_MPLS);
2770	rtnl_af_unregister(&mpls_af_ops);
2771	dev_remove_pack(&mpls_packet_type);
2772	unregister_netdevice_notifier(&mpls_dev_notifier);
2773	unregister_pernet_subsys(&mpls_net_ops);
2774	ipgre_tunnel_encap_del_mpls_ops();
2775}
2776module_exit(mpls_exit);
2777
2778MODULE_DESCRIPTION("MultiProtocol Label Switching");
2779MODULE_LICENSE("GPL v2");
2780MODULE_ALIAS_NETPROTO(PF_MPLS);