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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
 621	if (!ipv6_stub)
 622		return ERR_PTR(-EAFNOSUPPORT);
 623
 624	memset(&fl6, 0, sizeof(fl6));
 625	memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
 626	dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
 627	if (IS_ERR(dst))
 628		return ERR_CAST(dst);
 629
 630	dev = dst->dev;
 631	dev_hold(dev);
 632	dst_release(dst);
 633
 634	return dev;
 635}
 636#else
 637static struct net_device *inet6_fib_lookup_dev(struct net *net,
 638					       const void *addr)
 639{
 640	return ERR_PTR(-EAFNOSUPPORT);
 641}
 642#endif
 643
 644static struct net_device *find_outdev(struct net *net,
 645				      struct mpls_route *rt,
 646				      struct mpls_nh *nh, int oif)
 647{
 648	struct net_device *dev = NULL;
 649
 650	if (!oif) {
 651		switch (nh->nh_via_table) {
 652		case NEIGH_ARP_TABLE:
 653			dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
 654			break;
 655		case NEIGH_ND_TABLE:
 656			dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
 657			break;
 658		case NEIGH_LINK_TABLE:
 659			break;
 660		}
 661	} else {
 662		dev = dev_get_by_index(net, oif);
 663	}
 664
 665	if (!dev)
 666		return ERR_PTR(-ENODEV);
 667
 668	if (IS_ERR(dev))
 669		return dev;
 670
 671	/* The caller is holding rtnl anyways, so release the dev reference */
 672	dev_put(dev);
 673
 674	return dev;
 675}
 676
 677static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
 678			      struct mpls_nh *nh, int oif)
 679{
 680	struct net_device *dev = NULL;
 681	int err = -ENODEV;
 682
 683	dev = find_outdev(net, rt, nh, oif);
 684	if (IS_ERR(dev)) {
 685		err = PTR_ERR(dev);
 686		dev = NULL;
 687		goto errout;
 688	}
 689
 690	/* Ensure this is a supported device */
 691	err = -EINVAL;
 692	if (!mpls_dev_get(dev))
 693		goto errout;
 694
 695	if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
 696	    (dev->addr_len != nh->nh_via_alen))
 697		goto errout;
 698
 699	RCU_INIT_POINTER(nh->nh_dev, dev);
 700
 701	if (!(dev->flags & IFF_UP)) {
 702		nh->nh_flags |= RTNH_F_DEAD;
 703	} else {
 704		unsigned int flags;
 705
 706		flags = dev_get_flags(dev);
 707		if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
 708			nh->nh_flags |= RTNH_F_LINKDOWN;
 709	}
 710
 711	return 0;
 712
 713errout:
 714	return err;
 715}
 716
 717static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
 718		       u8 via_addr[], struct netlink_ext_ack *extack)
 719{
 720	struct rtvia *via = nla_data(nla);
 721	int err = -EINVAL;
 722	int alen;
 723
 724	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
 725		NL_SET_ERR_MSG_ATTR(extack, nla,
 726				    "Invalid attribute length for RTA_VIA");
 727		goto errout;
 728	}
 729	alen = nla_len(nla) -
 730			offsetof(struct rtvia, rtvia_addr);
 731	if (alen > MAX_VIA_ALEN) {
 732		NL_SET_ERR_MSG_ATTR(extack, nla,
 733				    "Invalid address length for RTA_VIA");
 734		goto errout;
 735	}
 736
 737	/* Validate the address family */
 738	switch (via->rtvia_family) {
 739	case AF_PACKET:
 740		*via_table = NEIGH_LINK_TABLE;
 741		break;
 742	case AF_INET:
 743		*via_table = NEIGH_ARP_TABLE;
 744		if (alen != 4)
 745			goto errout;
 746		break;
 747	case AF_INET6:
 748		*via_table = NEIGH_ND_TABLE;
 749		if (alen != 16)
 750			goto errout;
 751		break;
 752	default:
 753		/* Unsupported address family */
 754		goto errout;
 755	}
 756
 757	memcpy(via_addr, via->rtvia_addr, alen);
 758	*via_alen = alen;
 759	err = 0;
 760
 761errout:
 762	return err;
 763}
 764
 765static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
 766				  struct mpls_route *rt)
 767{
 768	struct net *net = cfg->rc_nlinfo.nl_net;
 769	struct mpls_nh *nh = rt->rt_nh;
 770	int err;
 771	int i;
 772
 773	if (!nh)
 774		return -ENOMEM;
 775
 776	nh->nh_labels = cfg->rc_output_labels;
 777	for (i = 0; i < nh->nh_labels; i++)
 778		nh->nh_label[i] = cfg->rc_output_label[i];
 779
 780	nh->nh_via_table = cfg->rc_via_table;
 781	memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
 782	nh->nh_via_alen = cfg->rc_via_alen;
 783
 784	err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
 785	if (err)
 786		goto errout;
 787
 788	if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
 789		rt->rt_nhn_alive--;
 790
 791	return 0;
 792
 793errout:
 794	return err;
 795}
 796
 797static int mpls_nh_build(struct net *net, struct mpls_route *rt,
 798			 struct mpls_nh *nh, int oif, struct nlattr *via,
 799			 struct nlattr *newdst, u8 max_labels,
 800			 struct netlink_ext_ack *extack)
 801{
 802	int err = -ENOMEM;
 803
 804	if (!nh)
 805		goto errout;
 806
 807	if (newdst) {
 808		err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
 809				     nh->nh_label, extack);
 810		if (err)
 811			goto errout;
 812	}
 813
 814	if (via) {
 815		err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
 816				  __mpls_nh_via(rt, nh), extack);
 817		if (err)
 818			goto errout;
 819	} else {
 820		nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
 821	}
 822
 823	err = mpls_nh_assign_dev(net, rt, nh, oif);
 824	if (err)
 825		goto errout;
 826
 827	return 0;
 828
 829errout:
 830	return err;
 831}
 832
 833static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
 834			      u8 cfg_via_alen, u8 *max_via_alen,
 835			      u8 *max_labels)
 836{
 837	int remaining = len;
 838	u8 nhs = 0;
 839
 840	*max_via_alen = 0;
 841	*max_labels = 0;
 842
 843	while (rtnh_ok(rtnh, remaining)) {
 844		struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
 845		int attrlen;
 846		u8 n_labels = 0;
 847
 848		attrlen = rtnh_attrlen(rtnh);
 849		nla = nla_find(attrs, attrlen, RTA_VIA);
 850		if (nla && nla_len(nla) >=
 851		    offsetof(struct rtvia, rtvia_addr)) {
 852			int via_alen = nla_len(nla) -
 853				offsetof(struct rtvia, rtvia_addr);
 854
 855			if (via_alen <= MAX_VIA_ALEN)
 856				*max_via_alen = max_t(u16, *max_via_alen,
 857						      via_alen);
 858		}
 859
 860		nla = nla_find(attrs, attrlen, RTA_NEWDST);
 861		if (nla &&
 862		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
 863				   NULL, NULL) != 0)
 864			return 0;
 865
 866		*max_labels = max_t(u8, *max_labels, n_labels);
 867
 868		/* number of nexthops is tracked by a u8.
 869		 * Check for overflow.
 870		 */
 871		if (nhs == 255)
 872			return 0;
 873		nhs++;
 874
 875		rtnh = rtnh_next(rtnh, &remaining);
 876	}
 877
 878	/* leftover implies invalid nexthop configuration, discard it */
 879	return remaining > 0 ? 0 : nhs;
 880}
 881
 882static int mpls_nh_build_multi(struct mpls_route_config *cfg,
 883			       struct mpls_route *rt, u8 max_labels,
 884			       struct netlink_ext_ack *extack)
 885{
 886	struct rtnexthop *rtnh = cfg->rc_mp;
 887	struct nlattr *nla_via, *nla_newdst;
 888	int remaining = cfg->rc_mp_len;
 889	int err = 0;
 890	u8 nhs = 0;
 891
 892	change_nexthops(rt) {
 893		int attrlen;
 894
 895		nla_via = NULL;
 896		nla_newdst = NULL;
 897
 898		err = -EINVAL;
 899		if (!rtnh_ok(rtnh, remaining))
 900			goto errout;
 901
 902		/* neither weighted multipath nor any flags
 903		 * are supported
 904		 */
 905		if (rtnh->rtnh_hops || rtnh->rtnh_flags)
 906			goto errout;
 907
 908		attrlen = rtnh_attrlen(rtnh);
 909		if (attrlen > 0) {
 910			struct nlattr *attrs = rtnh_attrs(rtnh);
 911
 912			nla_via = nla_find(attrs, attrlen, RTA_VIA);
 913			nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
 914		}
 915
 916		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
 917				    rtnh->rtnh_ifindex, nla_via, nla_newdst,
 918				    max_labels, extack);
 919		if (err)
 920			goto errout;
 921
 922		if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
 923			rt->rt_nhn_alive--;
 924
 925		rtnh = rtnh_next(rtnh, &remaining);
 926		nhs++;
 927	} endfor_nexthops(rt);
 928
 929	rt->rt_nhn = nhs;
 930
 931	return 0;
 932
 933errout:
 934	return err;
 935}
 936
 937static bool mpls_label_ok(struct net *net, unsigned int *index,
 938			  struct netlink_ext_ack *extack)
 939{
 940	bool is_ok = true;
 941
 942	/* Reserved labels may not be set */
 943	if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
 944		NL_SET_ERR_MSG(extack,
 945			       "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
 946		is_ok = false;
 947	}
 948
 949	/* The full 20 bit range may not be supported. */
 950	if (is_ok && *index >= net->mpls.platform_labels) {
 951		NL_SET_ERR_MSG(extack,
 952			       "Label >= configured maximum in platform_labels");
 953		is_ok = false;
 954	}
 955
 956	*index = array_index_nospec(*index, net->mpls.platform_labels);
 957	return is_ok;
 958}
 959
 960static int mpls_route_add(struct mpls_route_config *cfg,
 961			  struct netlink_ext_ack *extack)
 962{
 963	struct mpls_route __rcu **platform_label;
 964	struct net *net = cfg->rc_nlinfo.nl_net;
 965	struct mpls_route *rt, *old;
 966	int err = -EINVAL;
 967	u8 max_via_alen;
 968	unsigned index;
 969	u8 max_labels;
 970	u8 nhs;
 971
 972	index = cfg->rc_label;
 973
 974	/* If a label was not specified during insert pick one */
 975	if ((index == LABEL_NOT_SPECIFIED) &&
 976	    (cfg->rc_nlflags & NLM_F_CREATE)) {
 977		index = find_free_label(net);
 978	}
 979
 980	if (!mpls_label_ok(net, &index, extack))
 981		goto errout;
 982
 983	/* Append makes no sense with mpls */
 984	err = -EOPNOTSUPP;
 985	if (cfg->rc_nlflags & NLM_F_APPEND) {
 986		NL_SET_ERR_MSG(extack, "MPLS does not support route append");
 987		goto errout;
 988	}
 989
 990	err = -EEXIST;
 991	platform_label = rtnl_dereference(net->mpls.platform_label);
 992	old = rtnl_dereference(platform_label[index]);
 993	if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
 994		goto errout;
 995
 996	err = -EEXIST;
 997	if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
 998		goto errout;
 999
1000	err = -ENOENT;
1001	if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1002		goto errout;
1003
1004	err = -EINVAL;
1005	if (cfg->rc_mp) {
1006		nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1007					  cfg->rc_via_alen, &max_via_alen,
1008					  &max_labels);
1009	} else {
1010		max_via_alen = cfg->rc_via_alen;
1011		max_labels = cfg->rc_output_labels;
1012		nhs = 1;
1013	}
1014
1015	if (nhs == 0) {
1016		NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1017		goto errout;
1018	}
1019
1020	err = -ENOMEM;
1021	rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1022	if (IS_ERR(rt)) {
1023		err = PTR_ERR(rt);
1024		goto errout;
1025	}
1026
1027	rt->rt_protocol = cfg->rc_protocol;
1028	rt->rt_payload_type = cfg->rc_payload_type;
1029	rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1030
1031	if (cfg->rc_mp)
1032		err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1033	else
1034		err = mpls_nh_build_from_cfg(cfg, rt);
1035	if (err)
1036		goto freert;
1037
1038	mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1039
1040	return 0;
1041
1042freert:
1043	mpls_rt_free(rt);
1044errout:
1045	return err;
1046}
1047
1048static int mpls_route_del(struct mpls_route_config *cfg,
1049			  struct netlink_ext_ack *extack)
1050{
1051	struct net *net = cfg->rc_nlinfo.nl_net;
1052	unsigned index;
1053	int err = -EINVAL;
1054
1055	index = cfg->rc_label;
1056
1057	if (!mpls_label_ok(net, &index, extack))
1058		goto errout;
1059
1060	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1061
1062	err = 0;
1063errout:
1064	return err;
1065}
1066
1067static void mpls_get_stats(struct mpls_dev *mdev,
1068			   struct mpls_link_stats *stats)
1069{
1070	struct mpls_pcpu_stats *p;
1071	int i;
1072
1073	memset(stats, 0, sizeof(*stats));
1074
1075	for_each_possible_cpu(i) {
1076		struct mpls_link_stats local;
1077		unsigned int start;
1078
1079		p = per_cpu_ptr(mdev->stats, i);
1080		do {
1081			start = u64_stats_fetch_begin(&p->syncp);
1082			local = p->stats;
1083		} while (u64_stats_fetch_retry(&p->syncp, start));
1084
1085		stats->rx_packets	+= local.rx_packets;
1086		stats->rx_bytes		+= local.rx_bytes;
1087		stats->tx_packets	+= local.tx_packets;
1088		stats->tx_bytes		+= local.tx_bytes;
1089		stats->rx_errors	+= local.rx_errors;
1090		stats->tx_errors	+= local.tx_errors;
1091		stats->rx_dropped	+= local.rx_dropped;
1092		stats->tx_dropped	+= local.tx_dropped;
1093		stats->rx_noroute	+= local.rx_noroute;
1094	}
1095}
1096
1097static int mpls_fill_stats_af(struct sk_buff *skb,
1098			      const struct net_device *dev)
1099{
1100	struct mpls_link_stats *stats;
1101	struct mpls_dev *mdev;
1102	struct nlattr *nla;
1103
1104	mdev = mpls_dev_get(dev);
1105	if (!mdev)
1106		return -ENODATA;
1107
1108	nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1109				sizeof(struct mpls_link_stats),
1110				MPLS_STATS_UNSPEC);
1111	if (!nla)
1112		return -EMSGSIZE;
1113
1114	stats = nla_data(nla);
1115	mpls_get_stats(mdev, stats);
1116
1117	return 0;
1118}
1119
1120static size_t mpls_get_stats_af_size(const struct net_device *dev)
1121{
1122	struct mpls_dev *mdev;
1123
1124	mdev = mpls_dev_get(dev);
1125	if (!mdev)
1126		return 0;
1127
1128	return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1129}
1130
1131static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1132				     u32 portid, u32 seq, int event,
1133				     unsigned int flags, int type)
1134{
1135	struct nlmsghdr  *nlh;
1136	struct netconfmsg *ncm;
1137	bool all = false;
1138
1139	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1140			flags);
1141	if (!nlh)
1142		return -EMSGSIZE;
1143
1144	if (type == NETCONFA_ALL)
1145		all = true;
1146
1147	ncm = nlmsg_data(nlh);
1148	ncm->ncm_family = AF_MPLS;
1149
1150	if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1151		goto nla_put_failure;
1152
1153	if ((all || type == NETCONFA_INPUT) &&
1154	    nla_put_s32(skb, NETCONFA_INPUT,
1155			mdev->input_enabled) < 0)
1156		goto nla_put_failure;
1157
1158	nlmsg_end(skb, nlh);
1159	return 0;
1160
1161nla_put_failure:
1162	nlmsg_cancel(skb, nlh);
1163	return -EMSGSIZE;
1164}
1165
1166static int mpls_netconf_msgsize_devconf(int type)
1167{
1168	int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1169			+ nla_total_size(4); /* NETCONFA_IFINDEX */
1170	bool all = false;
1171
1172	if (type == NETCONFA_ALL)
1173		all = true;
1174
1175	if (all || type == NETCONFA_INPUT)
1176		size += nla_total_size(4);
1177
1178	return size;
1179}
1180
1181static void mpls_netconf_notify_devconf(struct net *net, int event,
1182					int type, struct mpls_dev *mdev)
1183{
1184	struct sk_buff *skb;
1185	int err = -ENOBUFS;
1186
1187	skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1188	if (!skb)
1189		goto errout;
1190
1191	err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1192	if (err < 0) {
1193		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1194		WARN_ON(err == -EMSGSIZE);
1195		kfree_skb(skb);
1196		goto errout;
1197	}
1198
1199	rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1200	return;
1201errout:
1202	if (err < 0)
1203		rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1204}
1205
1206static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1207	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
1208};
1209
1210static int mpls_netconf_valid_get_req(struct sk_buff *skb,
1211				      const struct nlmsghdr *nlh,
1212				      struct nlattr **tb,
1213				      struct netlink_ext_ack *extack)
1214{
1215	int i, err;
1216
1217	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
1218		NL_SET_ERR_MSG_MOD(extack,
1219				   "Invalid header for netconf get request");
1220		return -EINVAL;
1221	}
1222
1223	if (!netlink_strict_get_check(skb))
1224		return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
1225					      tb, NETCONFA_MAX,
1226					      devconf_mpls_policy, extack);
1227
1228	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
1229					    tb, NETCONFA_MAX,
1230					    devconf_mpls_policy, extack);
1231	if (err)
1232		return err;
1233
1234	for (i = 0; i <= NETCONFA_MAX; i++) {
1235		if (!tb[i])
1236			continue;
1237
1238		switch (i) {
1239		case NETCONFA_IFINDEX:
1240			break;
1241		default:
1242			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
1243			return -EINVAL;
1244		}
1245	}
1246
1247	return 0;
1248}
1249
1250static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1251				    struct nlmsghdr *nlh,
1252				    struct netlink_ext_ack *extack)
1253{
1254	struct net *net = sock_net(in_skb->sk);
1255	struct nlattr *tb[NETCONFA_MAX + 1];
1256	struct net_device *dev;
1257	struct mpls_dev *mdev;
1258	struct sk_buff *skb;
1259	int ifindex;
1260	int err;
1261
1262	err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
1263	if (err < 0)
1264		goto errout;
1265
1266	err = -EINVAL;
1267	if (!tb[NETCONFA_IFINDEX])
1268		goto errout;
1269
1270	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1271	dev = __dev_get_by_index(net, ifindex);
1272	if (!dev)
1273		goto errout;
1274
1275	mdev = mpls_dev_get(dev);
1276	if (!mdev)
1277		goto errout;
1278
1279	err = -ENOBUFS;
1280	skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1281	if (!skb)
1282		goto errout;
1283
1284	err = mpls_netconf_fill_devconf(skb, mdev,
1285					NETLINK_CB(in_skb).portid,
1286					nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1287					NETCONFA_ALL);
1288	if (err < 0) {
1289		/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1290		WARN_ON(err == -EMSGSIZE);
1291		kfree_skb(skb);
1292		goto errout;
1293	}
1294	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1295errout:
1296	return err;
1297}
1298
1299static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1300				     struct netlink_callback *cb)
1301{
1302	const struct nlmsghdr *nlh = cb->nlh;
1303	struct net *net = sock_net(skb->sk);
1304	struct hlist_head *head;
1305	struct net_device *dev;
1306	struct mpls_dev *mdev;
1307	int idx, s_idx;
1308	int h, s_h;
1309
1310	if (cb->strict_check) {
1311		struct netlink_ext_ack *extack = cb->extack;
1312		struct netconfmsg *ncm;
1313
1314		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1315			NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1316			return -EINVAL;
1317		}
1318
1319		if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1320			NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1321			return -EINVAL;
1322		}
1323	}
1324
1325	s_h = cb->args[0];
1326	s_idx = idx = cb->args[1];
1327
1328	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1329		idx = 0;
1330		head = &net->dev_index_head[h];
1331		rcu_read_lock();
1332		cb->seq = net->dev_base_seq;
1333		hlist_for_each_entry_rcu(dev, head, index_hlist) {
1334			if (idx < s_idx)
1335				goto cont;
1336			mdev = mpls_dev_get(dev);
1337			if (!mdev)
1338				goto cont;
1339			if (mpls_netconf_fill_devconf(skb, mdev,
1340						      NETLINK_CB(cb->skb).portid,
1341						      nlh->nlmsg_seq,
1342						      RTM_NEWNETCONF,
1343						      NLM_F_MULTI,
1344						      NETCONFA_ALL) < 0) {
1345				rcu_read_unlock();
1346				goto done;
1347			}
1348			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1349cont:
1350			idx++;
1351		}
1352		rcu_read_unlock();
1353	}
1354done:
1355	cb->args[0] = h;
1356	cb->args[1] = idx;
1357
1358	return skb->len;
1359}
1360
1361#define MPLS_PERDEV_SYSCTL_OFFSET(field)	\
1362	(&((struct mpls_dev *)0)->field)
1363
1364static int mpls_conf_proc(struct ctl_table *ctl, int write,
1365			  void *buffer, size_t *lenp, loff_t *ppos)
1366{
1367	int oval = *(int *)ctl->data;
1368	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1369
1370	if (write) {
1371		struct mpls_dev *mdev = ctl->extra1;
1372		int i = (int *)ctl->data - (int *)mdev;
1373		struct net *net = ctl->extra2;
1374		int val = *(int *)ctl->data;
1375
1376		if (i == offsetof(struct mpls_dev, input_enabled) &&
1377		    val != oval) {
1378			mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1379						    NETCONFA_INPUT, mdev);
1380		}
1381	}
1382
1383	return ret;
1384}
1385
1386static const struct ctl_table mpls_dev_table[] = {
1387	{
1388		.procname	= "input",
1389		.maxlen		= sizeof(int),
1390		.mode		= 0644,
1391		.proc_handler	= mpls_conf_proc,
1392		.data		= MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1393	},
1394	{ }
1395};
1396
1397static int mpls_dev_sysctl_register(struct net_device *dev,
1398				    struct mpls_dev *mdev)
1399{
1400	char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1401	struct net *net = dev_net(dev);
1402	struct ctl_table *table;
1403	int i;
1404
1405	table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1406	if (!table)
1407		goto out;
1408
1409	/* Table data contains only offsets relative to the base of
1410	 * the mdev at this point, so make them absolute.
1411	 */
1412	for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1413		table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1414		table[i].extra1 = mdev;
1415		table[i].extra2 = net;
1416	}
1417
1418	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1419
1420	mdev->sysctl = register_net_sysctl(net, path, table);
1421	if (!mdev->sysctl)
1422		goto free;
1423
1424	mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1425	return 0;
1426
1427free:
1428	kfree(table);
1429out:
1430	return -ENOBUFS;
1431}
1432
1433static void mpls_dev_sysctl_unregister(struct net_device *dev,
1434				       struct mpls_dev *mdev)
1435{
1436	struct net *net = dev_net(dev);
1437	struct ctl_table *table;
1438
1439	table = mdev->sysctl->ctl_table_arg;
1440	unregister_net_sysctl_table(mdev->sysctl);
1441	kfree(table);
1442
1443	mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1444}
1445
1446static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1447{
1448	struct mpls_dev *mdev;
1449	int err = -ENOMEM;
1450	int i;
1451
1452	ASSERT_RTNL();
1453
1454	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1455	if (!mdev)
1456		return ERR_PTR(err);
1457
1458	mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1459	if (!mdev->stats)
1460		goto free;
1461
1462	for_each_possible_cpu(i) {
1463		struct mpls_pcpu_stats *mpls_stats;
1464
1465		mpls_stats = per_cpu_ptr(mdev->stats, i);
1466		u64_stats_init(&mpls_stats->syncp);
1467	}
1468
1469	mdev->dev = dev;
1470
1471	err = mpls_dev_sysctl_register(dev, mdev);
1472	if (err)
1473		goto free;
1474
1475	rcu_assign_pointer(dev->mpls_ptr, mdev);
1476
1477	return mdev;
1478
1479free:
1480	free_percpu(mdev->stats);
1481	kfree(mdev);
1482	return ERR_PTR(err);
1483}
1484
1485static void mpls_dev_destroy_rcu(struct rcu_head *head)
1486{
1487	struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1488
1489	free_percpu(mdev->stats);
1490	kfree(mdev);
1491}
1492
1493static void mpls_ifdown(struct net_device *dev, int event)
1494{
1495	struct mpls_route __rcu **platform_label;
1496	struct net *net = dev_net(dev);
1497	u8 alive, deleted;
1498	unsigned index;
1499
1500	platform_label = rtnl_dereference(net->mpls.platform_label);
1501	for (index = 0; index < net->mpls.platform_labels; index++) {
1502		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1503
1504		if (!rt)
1505			continue;
1506
1507		alive = 0;
1508		deleted = 0;
1509		change_nexthops(rt) {
1510			unsigned int nh_flags = nh->nh_flags;
1511
1512			if (rtnl_dereference(nh->nh_dev) != dev)
1513				goto next;
1514
1515			switch (event) {
1516			case NETDEV_DOWN:
1517			case NETDEV_UNREGISTER:
1518				nh_flags |= RTNH_F_DEAD;
1519				fallthrough;
1520			case NETDEV_CHANGE:
1521				nh_flags |= RTNH_F_LINKDOWN;
1522				break;
1523			}
1524			if (event == NETDEV_UNREGISTER)
1525				RCU_INIT_POINTER(nh->nh_dev, NULL);
1526
1527			if (nh->nh_flags != nh_flags)
1528				WRITE_ONCE(nh->nh_flags, nh_flags);
1529next:
1530			if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1531				alive++;
1532			if (!rtnl_dereference(nh->nh_dev))
1533				deleted++;
1534		} endfor_nexthops(rt);
1535
1536		WRITE_ONCE(rt->rt_nhn_alive, alive);
1537
1538		/* if there are no more nexthops, delete the route */
1539		if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1540			mpls_route_update(net, index, NULL, NULL);
1541	}
1542}
1543
1544static void mpls_ifup(struct net_device *dev, unsigned int flags)
1545{
1546	struct mpls_route __rcu **platform_label;
1547	struct net *net = dev_net(dev);
1548	unsigned index;
1549	u8 alive;
1550
1551	platform_label = rtnl_dereference(net->mpls.platform_label);
1552	for (index = 0; index < net->mpls.platform_labels; index++) {
1553		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1554
1555		if (!rt)
1556			continue;
1557
1558		alive = 0;
1559		change_nexthops(rt) {
1560			unsigned int nh_flags = nh->nh_flags;
1561			struct net_device *nh_dev =
1562				rtnl_dereference(nh->nh_dev);
1563
1564			if (!(nh_flags & flags)) {
1565				alive++;
1566				continue;
1567			}
1568			if (nh_dev != dev)
1569				continue;
1570			alive++;
1571			nh_flags &= ~flags;
1572			WRITE_ONCE(nh->nh_flags, nh_flags);
1573		} endfor_nexthops(rt);
1574
1575		WRITE_ONCE(rt->rt_nhn_alive, alive);
1576	}
1577}
1578
1579static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1580			   void *ptr)
1581{
1582	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1583	struct mpls_dev *mdev;
1584	unsigned int flags;
1585
1586	if (event == NETDEV_REGISTER) {
1587		mdev = mpls_add_dev(dev);
1588		if (IS_ERR(mdev))
1589			return notifier_from_errno(PTR_ERR(mdev));
1590
1591		return NOTIFY_OK;
1592	}
1593
1594	mdev = mpls_dev_get(dev);
1595	if (!mdev)
1596		return NOTIFY_OK;
1597
1598	switch (event) {
1599	case NETDEV_DOWN:
1600		mpls_ifdown(dev, event);
1601		break;
1602	case NETDEV_UP:
1603		flags = dev_get_flags(dev);
1604		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1605			mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1606		else
1607			mpls_ifup(dev, RTNH_F_DEAD);
1608		break;
1609	case NETDEV_CHANGE:
1610		flags = dev_get_flags(dev);
1611		if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1612			mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1613		else
1614			mpls_ifdown(dev, event);
1615		break;
1616	case NETDEV_UNREGISTER:
1617		mpls_ifdown(dev, event);
1618		mdev = mpls_dev_get(dev);
1619		if (mdev) {
1620			mpls_dev_sysctl_unregister(dev, mdev);
1621			RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1622			call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1623		}
1624		break;
1625	case NETDEV_CHANGENAME:
1626		mdev = mpls_dev_get(dev);
1627		if (mdev) {
1628			int err;
1629
1630			mpls_dev_sysctl_unregister(dev, mdev);
1631			err = mpls_dev_sysctl_register(dev, mdev);
1632			if (err)
1633				return notifier_from_errno(err);
1634		}
1635		break;
1636	}
1637	return NOTIFY_OK;
1638}
1639
1640static struct notifier_block mpls_dev_notifier = {
1641	.notifier_call = mpls_dev_notify,
1642};
1643
1644static int nla_put_via(struct sk_buff *skb,
1645		       u8 table, const void *addr, int alen)
1646{
1647	static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1648		AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1649	};
1650	struct nlattr *nla;
1651	struct rtvia *via;
1652	int family = AF_UNSPEC;
1653
1654	nla = nla_reserve(skb, RTA_VIA, alen + 2);
1655	if (!nla)
1656		return -EMSGSIZE;
1657
1658	if (table <= NEIGH_NR_TABLES)
1659		family = table_to_family[table];
1660
1661	via = nla_data(nla);
1662	via->rtvia_family = family;
1663	memcpy(via->rtvia_addr, addr, alen);
1664	return 0;
1665}
1666
1667int nla_put_labels(struct sk_buff *skb, int attrtype,
1668		   u8 labels, const u32 label[])
1669{
1670	struct nlattr *nla;
1671	struct mpls_shim_hdr *nla_label;
1672	bool bos;
1673	int i;
1674	nla = nla_reserve(skb, attrtype, labels*4);
1675	if (!nla)
1676		return -EMSGSIZE;
1677
1678	nla_label = nla_data(nla);
1679	bos = true;
1680	for (i = labels - 1; i >= 0; i--) {
1681		nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1682		bos = false;
1683	}
1684
1685	return 0;
1686}
1687EXPORT_SYMBOL_GPL(nla_put_labels);
1688
1689int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1690		   u32 label[], struct netlink_ext_ack *extack)
1691{
1692	unsigned len = nla_len(nla);
1693	struct mpls_shim_hdr *nla_label;
1694	u8 nla_labels;
1695	bool bos;
1696	int i;
1697
1698	/* len needs to be an even multiple of 4 (the label size). Number
1699	 * of labels is a u8 so check for overflow.
1700	 */
1701	if (len & 3 || len / 4 > 255) {
1702		NL_SET_ERR_MSG_ATTR(extack, nla,
1703				    "Invalid length for labels attribute");
1704		return -EINVAL;
1705	}
1706
1707	/* Limit the number of new labels allowed */
1708	nla_labels = len/4;
1709	if (nla_labels > max_labels) {
1710		NL_SET_ERR_MSG(extack, "Too many labels");
1711		return -EINVAL;
1712	}
1713
1714	/* when label == NULL, caller wants number of labels */
1715	if (!label)
1716		goto out;
1717
1718	nla_label = nla_data(nla);
1719	bos = true;
1720	for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1721		struct mpls_entry_decoded dec;
1722		dec = mpls_entry_decode(nla_label + i);
1723
1724		/* Ensure the bottom of stack flag is properly set
1725		 * and ttl and tc are both clear.
1726		 */
1727		if (dec.ttl) {
1728			NL_SET_ERR_MSG_ATTR(extack, nla,
1729					    "TTL in label must be 0");
1730			return -EINVAL;
1731		}
1732
1733		if (dec.tc) {
1734			NL_SET_ERR_MSG_ATTR(extack, nla,
1735					    "Traffic class in label must be 0");
1736			return -EINVAL;
1737		}
1738
1739		if (dec.bos != bos) {
1740			NL_SET_BAD_ATTR(extack, nla);
1741			if (bos) {
1742				NL_SET_ERR_MSG(extack,
1743					       "BOS bit must be set in first label");
1744			} else {
1745				NL_SET_ERR_MSG(extack,
1746					       "BOS bit can only be set in first label");
1747			}
1748			return -EINVAL;
1749		}
1750
1751		switch (dec.label) {
1752		case MPLS_LABEL_IMPLNULL:
1753			/* RFC3032: This is a label that an LSR may
1754			 * assign and distribute, but which never
1755			 * actually appears in the encapsulation.
1756			 */
1757			NL_SET_ERR_MSG_ATTR(extack, nla,
1758					    "Implicit NULL Label (3) can not be used in encapsulation");
1759			return -EINVAL;
1760		}
1761
1762		label[i] = dec.label;
1763	}
1764out:
1765	*labels = nla_labels;
1766	return 0;
1767}
1768EXPORT_SYMBOL_GPL(nla_get_labels);
1769
1770static int rtm_to_route_config(struct sk_buff *skb,
1771			       struct nlmsghdr *nlh,
1772			       struct mpls_route_config *cfg,
1773			       struct netlink_ext_ack *extack)
1774{
1775	struct rtmsg *rtm;
1776	struct nlattr *tb[RTA_MAX+1];
1777	int index;
1778	int err;
1779
1780	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1781				     rtm_mpls_policy, extack);
1782	if (err < 0)
1783		goto errout;
1784
1785	err = -EINVAL;
1786	rtm = nlmsg_data(nlh);
1787
1788	if (rtm->rtm_family != AF_MPLS) {
1789		NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1790		goto errout;
1791	}
1792	if (rtm->rtm_dst_len != 20) {
1793		NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1794		goto errout;
1795	}
1796	if (rtm->rtm_src_len != 0) {
1797		NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1798		goto errout;
1799	}
1800	if (rtm->rtm_tos != 0) {
1801		NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1802		goto errout;
1803	}
1804	if (rtm->rtm_table != RT_TABLE_MAIN) {
1805		NL_SET_ERR_MSG(extack,
1806			       "MPLS only supports the main route table");
1807		goto errout;
1808	}
1809	/* Any value is acceptable for rtm_protocol */
1810
1811	/* As mpls uses destination specific addresses
1812	 * (or source specific address in the case of multicast)
1813	 * all addresses have universal scope.
1814	 */
1815	if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1816		NL_SET_ERR_MSG(extack,
1817			       "Invalid route scope  - MPLS only supports UNIVERSE");
1818		goto errout;
1819	}
1820	if (rtm->rtm_type != RTN_UNICAST) {
1821		NL_SET_ERR_MSG(extack,
1822			       "Invalid route type - MPLS only supports UNICAST");
1823		goto errout;
1824	}
1825	if (rtm->rtm_flags != 0) {
1826		NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1827		goto errout;
1828	}
1829
1830	cfg->rc_label		= LABEL_NOT_SPECIFIED;
1831	cfg->rc_protocol	= rtm->rtm_protocol;
1832	cfg->rc_via_table	= MPLS_NEIGH_TABLE_UNSPEC;
1833	cfg->rc_ttl_propagate	= MPLS_TTL_PROP_DEFAULT;
1834	cfg->rc_nlflags		= nlh->nlmsg_flags;
1835	cfg->rc_nlinfo.portid	= NETLINK_CB(skb).portid;
1836	cfg->rc_nlinfo.nlh	= nlh;
1837	cfg->rc_nlinfo.nl_net	= sock_net(skb->sk);
1838
1839	for (index = 0; index <= RTA_MAX; index++) {
1840		struct nlattr *nla = tb[index];
1841		if (!nla)
1842			continue;
1843
1844		switch (index) {
1845		case RTA_OIF:
1846			cfg->rc_ifindex = nla_get_u32(nla);
1847			break;
1848		case RTA_NEWDST:
1849			if (nla_get_labels(nla, MAX_NEW_LABELS,
1850					   &cfg->rc_output_labels,
1851					   cfg->rc_output_label, extack))
1852				goto errout;
1853			break;
1854		case RTA_DST:
1855		{
1856			u8 label_count;
1857			if (nla_get_labels(nla, 1, &label_count,
1858					   &cfg->rc_label, extack))
1859				goto errout;
1860
1861			if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1862					   &cfg->rc_label, extack))
1863				goto errout;
1864			break;
1865		}
1866		case RTA_GATEWAY:
1867			NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1868			goto errout;
1869		case RTA_VIA:
1870		{
1871			if (nla_get_via(nla, &cfg->rc_via_alen,
1872					&cfg->rc_via_table, cfg->rc_via,
1873					extack))
1874				goto errout;
1875			break;
1876		}
1877		case RTA_MULTIPATH:
1878		{
1879			cfg->rc_mp = nla_data(nla);
1880			cfg->rc_mp_len = nla_len(nla);
1881			break;
1882		}
1883		case RTA_TTL_PROPAGATE:
1884		{
1885			u8 ttl_propagate = nla_get_u8(nla);
1886
1887			if (ttl_propagate > 1) {
1888				NL_SET_ERR_MSG_ATTR(extack, nla,
1889						    "RTA_TTL_PROPAGATE can only be 0 or 1");
1890				goto errout;
1891			}
1892			cfg->rc_ttl_propagate = ttl_propagate ?
1893				MPLS_TTL_PROP_ENABLED :
1894				MPLS_TTL_PROP_DISABLED;
1895			break;
1896		}
1897		default:
1898			NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1899			/* Unsupported attribute */
1900			goto errout;
1901		}
1902	}
1903
1904	err = 0;
1905errout:
1906	return err;
1907}
1908
1909static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1910			     struct netlink_ext_ack *extack)
1911{
1912	struct mpls_route_config *cfg;
1913	int err;
1914
1915	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1916	if (!cfg)
1917		return -ENOMEM;
1918
1919	err = rtm_to_route_config(skb, nlh, cfg, extack);
1920	if (err < 0)
1921		goto out;
1922
1923	err = mpls_route_del(cfg, extack);
1924out:
1925	kfree(cfg);
1926
1927	return err;
1928}
1929
1930
1931static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1932			     struct netlink_ext_ack *extack)
1933{
1934	struct mpls_route_config *cfg;
1935	int err;
1936
1937	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1938	if (!cfg)
1939		return -ENOMEM;
1940
1941	err = rtm_to_route_config(skb, nlh, cfg, extack);
1942	if (err < 0)
1943		goto out;
1944
1945	err = mpls_route_add(cfg, extack);
1946out:
1947	kfree(cfg);
1948
1949	return err;
1950}
1951
1952static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1953			   u32 label, struct mpls_route *rt, int flags)
1954{
1955	struct net_device *dev;
1956	struct nlmsghdr *nlh;
1957	struct rtmsg *rtm;
1958
1959	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1960	if (nlh == NULL)
1961		return -EMSGSIZE;
1962
1963	rtm = nlmsg_data(nlh);
1964	rtm->rtm_family = AF_MPLS;
1965	rtm->rtm_dst_len = 20;
1966	rtm->rtm_src_len = 0;
1967	rtm->rtm_tos = 0;
1968	rtm->rtm_table = RT_TABLE_MAIN;
1969	rtm->rtm_protocol = rt->rt_protocol;
1970	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1971	rtm->rtm_type = RTN_UNICAST;
1972	rtm->rtm_flags = 0;
1973
1974	if (nla_put_labels(skb, RTA_DST, 1, &label))
1975		goto nla_put_failure;
1976
1977	if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1978		bool ttl_propagate =
1979			rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1980
1981		if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1982			       ttl_propagate))
1983			goto nla_put_failure;
1984	}
1985	if (rt->rt_nhn == 1) {
1986		const struct mpls_nh *nh = rt->rt_nh;
1987
1988		if (nh->nh_labels &&
1989		    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
1990				   nh->nh_label))
1991			goto nla_put_failure;
1992		if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1993		    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
1994				nh->nh_via_alen))
1995			goto nla_put_failure;
1996		dev = rtnl_dereference(nh->nh_dev);
1997		if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
1998			goto nla_put_failure;
1999		if (nh->nh_flags & RTNH_F_LINKDOWN)
2000			rtm->rtm_flags |= RTNH_F_LINKDOWN;
2001		if (nh->nh_flags & RTNH_F_DEAD)
2002			rtm->rtm_flags |= RTNH_F_DEAD;
2003	} else {
2004		struct rtnexthop *rtnh;
2005		struct nlattr *mp;
2006		u8 linkdown = 0;
2007		u8 dead = 0;
2008
2009		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2010		if (!mp)
2011			goto nla_put_failure;
2012
2013		for_nexthops(rt) {
2014			dev = rtnl_dereference(nh->nh_dev);
2015			if (!dev)
2016				continue;
2017
2018			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2019			if (!rtnh)
2020				goto nla_put_failure;
2021
2022			rtnh->rtnh_ifindex = dev->ifindex;
2023			if (nh->nh_flags & RTNH_F_LINKDOWN) {
2024				rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2025				linkdown++;
2026			}
2027			if (nh->nh_flags & RTNH_F_DEAD) {
2028				rtnh->rtnh_flags |= RTNH_F_DEAD;
2029				dead++;
2030			}
2031
2032			if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2033							    nh->nh_labels,
2034							    nh->nh_label))
2035				goto nla_put_failure;
2036			if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2037			    nla_put_via(skb, nh->nh_via_table,
2038					mpls_nh_via(rt, nh),
2039					nh->nh_via_alen))
2040				goto nla_put_failure;
2041
2042			/* length of rtnetlink header + attributes */
2043			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2044		} endfor_nexthops(rt);
2045
2046		if (linkdown == rt->rt_nhn)
2047			rtm->rtm_flags |= RTNH_F_LINKDOWN;
2048		if (dead == rt->rt_nhn)
2049			rtm->rtm_flags |= RTNH_F_DEAD;
2050
2051		nla_nest_end(skb, mp);
2052	}
2053
2054	nlmsg_end(skb, nlh);
2055	return 0;
2056
2057nla_put_failure:
2058	nlmsg_cancel(skb, nlh);
2059	return -EMSGSIZE;
2060}
2061
2062#if IS_ENABLED(CONFIG_INET)
2063static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2064				   struct fib_dump_filter *filter,
2065				   struct netlink_callback *cb)
2066{
2067	return ip_valid_fib_dump_req(net, nlh, filter, cb);
2068}
2069#else
2070static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2071				   struct fib_dump_filter *filter,
2072				   struct netlink_callback *cb)
2073{
2074	struct netlink_ext_ack *extack = cb->extack;
2075	struct nlattr *tb[RTA_MAX + 1];
2076	struct rtmsg *rtm;
2077	int err, i;
2078
2079	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2080		NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2081		return -EINVAL;
2082	}
2083
2084	rtm = nlmsg_data(nlh);
2085	if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
2086	    rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
2087	    rtm->rtm_flags) {
2088		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2089		return -EINVAL;
2090	}
2091
2092	if (rtm->rtm_protocol) {
2093		filter->protocol = rtm->rtm_protocol;
2094		filter->filter_set = 1;
2095		cb->answer_flags = NLM_F_DUMP_FILTERED;
2096	}
2097
2098	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2099					    rtm_mpls_policy, extack);
2100	if (err < 0)
2101		return err;
2102
2103	for (i = 0; i <= RTA_MAX; ++i) {
2104		int ifindex;
2105
2106		if (i == RTA_OIF) {
2107			ifindex = nla_get_u32(tb[i]);
2108			filter->dev = __dev_get_by_index(net, ifindex);
2109			if (!filter->dev)
2110				return -ENODEV;
2111			filter->filter_set = 1;
2112		} else if (tb[i]) {
2113			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2114			return -EINVAL;
2115		}
2116	}
2117
2118	return 0;
2119}
2120#endif
2121
2122static bool mpls_rt_uses_dev(struct mpls_route *rt,
2123			     const struct net_device *dev)
2124{
2125	struct net_device *nh_dev;
2126
2127	if (rt->rt_nhn == 1) {
2128		struct mpls_nh *nh = rt->rt_nh;
2129
2130		nh_dev = rtnl_dereference(nh->nh_dev);
2131		if (dev == nh_dev)
2132			return true;
2133	} else {
2134		for_nexthops(rt) {
2135			nh_dev = rtnl_dereference(nh->nh_dev);
2136			if (nh_dev == dev)
2137				return true;
2138		} endfor_nexthops(rt);
2139	}
2140
2141	return false;
2142}
2143
2144static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2145{
2146	const struct nlmsghdr *nlh = cb->nlh;
2147	struct net *net = sock_net(skb->sk);
2148	struct mpls_route __rcu **platform_label;
2149	struct fib_dump_filter filter = {};
2150	unsigned int flags = NLM_F_MULTI;
2151	size_t platform_labels;
2152	unsigned int index;
2153
2154	ASSERT_RTNL();
2155
2156	if (cb->strict_check) {
2157		int err;
2158
2159		err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2160		if (err < 0)
2161			return err;
2162
2163		/* for MPLS, there is only 1 table with fixed type and flags.
2164		 * If either are set in the filter then return nothing.
2165		 */
2166		if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2167		    (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2168		     filter.flags)
2169			return skb->len;
2170	}
2171
2172	index = cb->args[0];
2173	if (index < MPLS_LABEL_FIRST_UNRESERVED)
2174		index = MPLS_LABEL_FIRST_UNRESERVED;
2175
2176	platform_label = rtnl_dereference(net->mpls.platform_label);
2177	platform_labels = net->mpls.platform_labels;
2178
2179	if (filter.filter_set)
2180		flags |= NLM_F_DUMP_FILTERED;
2181
2182	for (; index < platform_labels; index++) {
2183		struct mpls_route *rt;
2184
2185		rt = rtnl_dereference(platform_label[index]);
2186		if (!rt)
2187			continue;
2188
2189		if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2190		    (filter.protocol && rt->rt_protocol != filter.protocol))
2191			continue;
2192
2193		if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2194				    cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2195				    index, rt, flags) < 0)
2196			break;
2197	}
2198	cb->args[0] = index;
2199
2200	return skb->len;
2201}
2202
2203static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2204{
2205	size_t payload =
2206		NLMSG_ALIGN(sizeof(struct rtmsg))
2207		+ nla_total_size(4)			/* RTA_DST */
2208		+ nla_total_size(1);			/* RTA_TTL_PROPAGATE */
2209
2210	if (rt->rt_nhn == 1) {
2211		struct mpls_nh *nh = rt->rt_nh;
2212
2213		if (nh->nh_dev)
2214			payload += nla_total_size(4); /* RTA_OIF */
2215		if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2216			payload += nla_total_size(2 + nh->nh_via_alen);
2217		if (nh->nh_labels) /* RTA_NEWDST */
2218			payload += nla_total_size(nh->nh_labels * 4);
2219	} else {
2220		/* each nexthop is packed in an attribute */
2221		size_t nhsize = 0;
2222
2223		for_nexthops(rt) {
2224			if (!rtnl_dereference(nh->nh_dev))
2225				continue;
2226			nhsize += nla_total_size(sizeof(struct rtnexthop));
2227			/* RTA_VIA */
2228			if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2229				nhsize += nla_total_size(2 + nh->nh_via_alen);
2230			if (nh->nh_labels)
2231				nhsize += nla_total_size(nh->nh_labels * 4);
2232		} endfor_nexthops(rt);
2233		/* nested attribute */
2234		payload += nla_total_size(nhsize);
2235	}
2236
2237	return payload;
2238}
2239
2240static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2241		       struct nlmsghdr *nlh, struct net *net, u32 portid,
2242		       unsigned int nlm_flags)
2243{
2244	struct sk_buff *skb;
2245	u32 seq = nlh ? nlh->nlmsg_seq : 0;
2246	int err = -ENOBUFS;
2247
2248	skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2249	if (skb == NULL)
2250		goto errout;
2251
2252	err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2253	if (err < 0) {
2254		/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2255		WARN_ON(err == -EMSGSIZE);
2256		kfree_skb(skb);
2257		goto errout;
2258	}
2259	rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2260
2261	return;
2262errout:
2263	if (err < 0)
2264		rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2265}
2266
2267static int mpls_valid_getroute_req(struct sk_buff *skb,
2268				   const struct nlmsghdr *nlh,
2269				   struct nlattr **tb,
2270				   struct netlink_ext_ack *extack)
2271{
2272	struct rtmsg *rtm;
2273	int i, err;
2274
2275	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2276		NL_SET_ERR_MSG_MOD(extack,
2277				   "Invalid header for get route request");
2278		return -EINVAL;
2279	}
2280
2281	if (!netlink_strict_get_check(skb))
2282		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2283					      rtm_mpls_policy, extack);
2284
2285	rtm = nlmsg_data(nlh);
2286	if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2287	    rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2288	    rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2289		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2290		return -EINVAL;
2291	}
2292	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2293		NL_SET_ERR_MSG_MOD(extack,
2294				   "Invalid flags for get route request");
2295		return -EINVAL;
2296	}
2297
2298	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2299					    rtm_mpls_policy, extack);
2300	if (err)
2301		return err;
2302
2303	if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2304		NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2305		return -EINVAL;
2306	}
2307
2308	for (i = 0; i <= RTA_MAX; i++) {
2309		if (!tb[i])
2310			continue;
2311
2312		switch (i) {
2313		case RTA_DST:
2314		case RTA_NEWDST:
2315			break;
2316		default:
2317			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2318			return -EINVAL;
2319		}
2320	}
2321
2322	return 0;
2323}
2324
2325static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2326			 struct netlink_ext_ack *extack)
2327{
2328	struct net *net = sock_net(in_skb->sk);
2329	u32 portid = NETLINK_CB(in_skb).portid;
2330	u32 in_label = LABEL_NOT_SPECIFIED;
2331	struct nlattr *tb[RTA_MAX + 1];
2332	u32 labels[MAX_NEW_LABELS];
2333	struct mpls_shim_hdr *hdr;
2334	unsigned int hdr_size = 0;
2335	struct net_device *dev;
2336	struct mpls_route *rt;
2337	struct rtmsg *rtm, *r;
2338	struct nlmsghdr *nlh;
2339	struct sk_buff *skb;
2340	struct mpls_nh *nh;
2341	u8 n_labels;
2342	int err;
2343
2344	err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2345	if (err < 0)
2346		goto errout;
2347
2348	rtm = nlmsg_data(in_nlh);
2349
2350	if (tb[RTA_DST]) {
2351		u8 label_count;
2352
2353		if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2354				   &in_label, extack)) {
2355			err = -EINVAL;
2356			goto errout;
2357		}
2358
2359		if (!mpls_label_ok(net, &in_label, extack)) {
2360			err = -EINVAL;
2361			goto errout;
2362		}
2363	}
2364
2365	rt = mpls_route_input_rcu(net, in_label);
2366	if (!rt) {
2367		err = -ENETUNREACH;
2368		goto errout;
2369	}
2370
2371	if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2372		skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2373		if (!skb) {
2374			err = -ENOBUFS;
2375			goto errout;
2376		}
2377
2378		err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2379				      RTM_NEWROUTE, in_label, rt, 0);
2380		if (err < 0) {
2381			/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2382			WARN_ON(err == -EMSGSIZE);
2383			goto errout_free;
2384		}
2385
2386		return rtnl_unicast(skb, net, portid);
2387	}
2388
2389	if (tb[RTA_NEWDST]) {
2390		if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2391				   labels, extack) != 0) {
2392			err = -EINVAL;
2393			goto errout;
2394		}
2395
2396		hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2397	}
2398
2399	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2400	if (!skb) {
2401		err = -ENOBUFS;
2402		goto errout;
2403	}
2404
2405	skb->protocol = htons(ETH_P_MPLS_UC);
2406
2407	if (hdr_size) {
2408		bool bos;
2409		int i;
2410
2411		if (skb_cow(skb, hdr_size)) {
2412			err = -ENOBUFS;
2413			goto errout_free;
2414		}
2415
2416		skb_reserve(skb, hdr_size);
2417		skb_push(skb, hdr_size);
2418		skb_reset_network_header(skb);
2419
2420		/* Push new labels */
2421		hdr = mpls_hdr(skb);
2422		bos = true;
2423		for (i = n_labels - 1; i >= 0; i--) {
2424			hdr[i] = mpls_entry_encode(labels[i],
2425						   1, 0, bos);
2426			bos = false;
2427		}
2428	}
2429
2430	nh = mpls_select_multipath(rt, skb);
2431	if (!nh) {
2432		err = -ENETUNREACH;
2433		goto errout_free;
2434	}
2435
2436	if (hdr_size) {
2437		skb_pull(skb, hdr_size);
2438		skb_reset_network_header(skb);
2439	}
2440
2441	nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2442			RTM_NEWROUTE, sizeof(*r), 0);
2443	if (!nlh) {
2444		err = -EMSGSIZE;
2445		goto errout_free;
2446	}
2447
2448	r = nlmsg_data(nlh);
2449	r->rtm_family	 = AF_MPLS;
2450	r->rtm_dst_len	= 20;
2451	r->rtm_src_len	= 0;
2452	r->rtm_table	= RT_TABLE_MAIN;
2453	r->rtm_type	= RTN_UNICAST;
2454	r->rtm_scope	= RT_SCOPE_UNIVERSE;
2455	r->rtm_protocol = rt->rt_protocol;
2456	r->rtm_flags	= 0;
2457
2458	if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2459		goto nla_put_failure;
2460
2461	if (nh->nh_labels &&
2462	    nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2463			   nh->nh_label))
2464		goto nla_put_failure;
2465
2466	if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2467	    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2468			nh->nh_via_alen))
2469		goto nla_put_failure;
2470	dev = rtnl_dereference(nh->nh_dev);
2471	if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2472		goto nla_put_failure;
2473
2474	nlmsg_end(skb, nlh);
2475
2476	err = rtnl_unicast(skb, net, portid);
2477errout:
2478	return err;
2479
2480nla_put_failure:
2481	nlmsg_cancel(skb, nlh);
2482	err = -EMSGSIZE;
2483errout_free:
2484	kfree_skb(skb);
2485	return err;
2486}
2487
2488static int resize_platform_label_table(struct net *net, size_t limit)
2489{
2490	size_t size = sizeof(struct mpls_route *) * limit;
2491	size_t old_limit;
2492	size_t cp_size;
2493	struct mpls_route __rcu **labels = NULL, **old;
2494	struct mpls_route *rt0 = NULL, *rt2 = NULL;
2495	unsigned index;
2496
2497	if (size) {
2498		labels = kvzalloc(size, GFP_KERNEL);
2499		if (!labels)
2500			goto nolabels;
2501	}
2502
2503	/* In case the predefined labels need to be populated */
2504	if (limit > MPLS_LABEL_IPV4NULL) {
2505		struct net_device *lo = net->loopback_dev;
2506		rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2507		if (IS_ERR(rt0))
2508			goto nort0;
2509		RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2510		rt0->rt_protocol = RTPROT_KERNEL;
2511		rt0->rt_payload_type = MPT_IPV4;
2512		rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2513		rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2514		rt0->rt_nh->nh_via_alen = lo->addr_len;
2515		memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2516		       lo->addr_len);
2517	}
2518	if (limit > MPLS_LABEL_IPV6NULL) {
2519		struct net_device *lo = net->loopback_dev;
2520		rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2521		if (IS_ERR(rt2))
2522			goto nort2;
2523		RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2524		rt2->rt_protocol = RTPROT_KERNEL;
2525		rt2->rt_payload_type = MPT_IPV6;
2526		rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2527		rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2528		rt2->rt_nh->nh_via_alen = lo->addr_len;
2529		memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2530		       lo->addr_len);
2531	}
2532
2533	rtnl_lock();
2534	/* Remember the original table */
2535	old = rtnl_dereference(net->mpls.platform_label);
2536	old_limit = net->mpls.platform_labels;
2537
2538	/* Free any labels beyond the new table */
2539	for (index = limit; index < old_limit; index++)
2540		mpls_route_update(net, index, NULL, NULL);
2541
2542	/* Copy over the old labels */
2543	cp_size = size;
2544	if (old_limit < limit)
2545		cp_size = old_limit * sizeof(struct mpls_route *);
2546
2547	memcpy(labels, old, cp_size);
2548
2549	/* If needed set the predefined labels */
2550	if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2551	    (limit > MPLS_LABEL_IPV6NULL)) {
2552		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2553		rt2 = NULL;
2554	}
2555
2556	if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2557	    (limit > MPLS_LABEL_IPV4NULL)) {
2558		RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2559		rt0 = NULL;
2560	}
2561
2562	/* Update the global pointers */
2563	net->mpls.platform_labels = limit;
2564	rcu_assign_pointer(net->mpls.platform_label, labels);
2565
2566	rtnl_unlock();
2567
2568	mpls_rt_free(rt2);
2569	mpls_rt_free(rt0);
2570
2571	if (old) {
2572		synchronize_rcu();
2573		kvfree(old);
2574	}
2575	return 0;
2576
2577nort2:
2578	mpls_rt_free(rt0);
2579nort0:
2580	kvfree(labels);
2581nolabels:
2582	return -ENOMEM;
2583}
2584
2585static int mpls_platform_labels(struct ctl_table *table, int write,
2586				void *buffer, size_t *lenp, loff_t *ppos)
2587{
2588	struct net *net = table->data;
2589	int platform_labels = net->mpls.platform_labels;
2590	int ret;
2591	struct ctl_table tmp = {
2592		.procname	= table->procname,
2593		.data		= &platform_labels,
2594		.maxlen		= sizeof(int),
2595		.mode		= table->mode,
2596		.extra1		= SYSCTL_ZERO,
2597		.extra2		= &label_limit,
2598	};
2599
2600	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2601
2602	if (write && ret == 0)
2603		ret = resize_platform_label_table(net, platform_labels);
2604
2605	return ret;
2606}
2607
2608#define MPLS_NS_SYSCTL_OFFSET(field)		\
2609	(&((struct net *)0)->field)
2610
2611static const struct ctl_table mpls_table[] = {
2612	{
2613		.procname	= "platform_labels",
2614		.data		= NULL,
2615		.maxlen		= sizeof(int),
2616		.mode		= 0644,
2617		.proc_handler	= mpls_platform_labels,
2618	},
2619	{
2620		.procname	= "ip_ttl_propagate",
2621		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2622		.maxlen		= sizeof(int),
2623		.mode		= 0644,
2624		.proc_handler	= proc_dointvec_minmax,
2625		.extra1		= SYSCTL_ZERO,
2626		.extra2		= SYSCTL_ONE,
2627	},
2628	{
2629		.procname	= "default_ttl",
2630		.data		= MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2631		.maxlen		= sizeof(int),
2632		.mode		= 0644,
2633		.proc_handler	= proc_dointvec_minmax,
2634		.extra1		= SYSCTL_ONE,
2635		.extra2		= &ttl_max,
2636	},
2637	{ }
2638};
2639
2640static int mpls_net_init(struct net *net)
2641{
2642	struct ctl_table *table;
2643	int i;
2644
2645	net->mpls.platform_labels = 0;
2646	net->mpls.platform_label = NULL;
2647	net->mpls.ip_ttl_propagate = 1;
2648	net->mpls.default_ttl = 255;
2649
2650	table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2651	if (table == NULL)
2652		return -ENOMEM;
2653
2654	/* Table data contains only offsets relative to the base of
2655	 * the mdev at this point, so make them absolute.
2656	 */
2657	for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2658		table[i].data = (char *)net + (uintptr_t)table[i].data;
2659
2660	net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2661	if (net->mpls.ctl == NULL) {
2662		kfree(table);
2663		return -ENOMEM;
2664	}
2665
2666	return 0;
2667}
2668
2669static void mpls_net_exit(struct net *net)
2670{
2671	struct mpls_route __rcu **platform_label;
2672	size_t platform_labels;
2673	struct ctl_table *table;
2674	unsigned int index;
2675
2676	table = net->mpls.ctl->ctl_table_arg;
2677	unregister_net_sysctl_table(net->mpls.ctl);
2678	kfree(table);
2679
2680	/* An rcu grace period has passed since there was a device in
2681	 * the network namespace (and thus the last in flight packet)
2682	 * left this network namespace.  This is because
2683	 * unregister_netdevice_many and netdev_run_todo has completed
2684	 * for each network device that was in this network namespace.
2685	 *
2686	 * As such no additional rcu synchronization is necessary when
2687	 * freeing the platform_label table.
2688	 */
2689	rtnl_lock();
2690	platform_label = rtnl_dereference(net->mpls.platform_label);
2691	platform_labels = net->mpls.platform_labels;
2692	for (index = 0; index < platform_labels; index++) {
2693		struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2694		RCU_INIT_POINTER(platform_label[index], NULL);
2695		mpls_notify_route(net, index, rt, NULL, NULL);
2696		mpls_rt_free(rt);
2697	}
2698	rtnl_unlock();
2699
2700	kvfree(platform_label);
2701}
2702
2703static struct pernet_operations mpls_net_ops = {
2704	.init = mpls_net_init,
2705	.exit = mpls_net_exit,
2706};
2707
2708static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2709	.family		   = AF_MPLS,
2710	.fill_stats_af	   = mpls_fill_stats_af,
2711	.get_stats_af_size = mpls_get_stats_af_size,
2712};
2713
2714static int __init mpls_init(void)
2715{
2716	int err;
2717
2718	BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2719
2720	err = register_pernet_subsys(&mpls_net_ops);
2721	if (err)
2722		goto out;
2723
2724	err = register_netdevice_notifier(&mpls_dev_notifier);
2725	if (err)
2726		goto out_unregister_pernet;
2727
2728	dev_add_pack(&mpls_packet_type);
2729
2730	rtnl_af_register(&mpls_af_ops);
2731
2732	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
2733			     mpls_rtm_newroute, NULL, 0);
2734	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
2735			     mpls_rtm_delroute, NULL, 0);
2736	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
2737			     mpls_getroute, mpls_dump_routes, 0);
2738	rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2739			     mpls_netconf_get_devconf,
2740			     mpls_netconf_dump_devconf, 0);
2741	err = ipgre_tunnel_encap_add_mpls_ops();
2742	if (err)
2743		pr_err("Can't add mpls over gre tunnel ops\n");
2744
2745	err = 0;
2746out:
2747	return err;
2748
2749out_unregister_pernet:
2750	unregister_pernet_subsys(&mpls_net_ops);
2751	goto out;
2752}
2753module_init(mpls_init);
2754
2755static void __exit mpls_exit(void)
2756{
2757	rtnl_unregister_all(PF_MPLS);
2758	rtnl_af_unregister(&mpls_af_ops);
2759	dev_remove_pack(&mpls_packet_type);
2760	unregister_netdevice_notifier(&mpls_dev_notifier);
2761	unregister_pernet_subsys(&mpls_net_ops);
2762	ipgre_tunnel_encap_del_mpls_ops();
2763}
2764module_exit(mpls_exit);
2765
2766MODULE_DESCRIPTION("MultiProtocol Label Switching");
2767MODULE_LICENSE("GPL v2");
2768MODULE_ALIAS_NETPROTO(PF_MPLS);