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