ip6_vti.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	IPv6 virtual tunneling interface
   4 *
   5 *	Copyright (C) 2013 secunet Security Networks AG
   6 *
   7 *	Author:
   8 *	Steffen Klassert <steffen.klassert@secunet.com>
   9 *
  10 *	Based on:
  11 *	net/ipv6/ip6_tunnel.c
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/capability.h>
  16#include <linux/errno.h>
  17#include <linux/types.h>
  18#include <linux/sockios.h>
  19#include <linux/icmp.h>
  20#include <linux/if.h>
  21#include <linux/in.h>
  22#include <linux/ip.h>
  23#include <linux/net.h>
  24#include <linux/in6.h>
  25#include <linux/netdevice.h>
  26#include <linux/if_arp.h>
  27#include <linux/icmpv6.h>
  28#include <linux/init.h>
  29#include <linux/route.h>
  30#include <linux/rtnetlink.h>
  31#include <linux/netfilter_ipv6.h>
  32#include <linux/slab.h>
  33#include <linux/hash.h>
  34
  35#include <linux/uaccess.h>
  36#include <linux/atomic.h>
  37
  38#include <net/icmp.h>
  39#include <net/ip.h>
  40#include <net/ip_tunnels.h>
  41#include <net/ipv6.h>
  42#include <net/ip6_route.h>
  43#include <net/addrconf.h>
  44#include <net/ip6_tunnel.h>
  45#include <net/xfrm.h>
  46#include <net/net_namespace.h>
  47#include <net/netns/generic.h>
  48#include <net/netdev_lock.h>
  49#include <linux/etherdevice.h>
  50
  51#define IP6_VTI_HASH_SIZE_SHIFT  5
  52#define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT)
  53
  54static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  55{
  56	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  57
  58	return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT);
  59}
  60
  61static int vti6_dev_init(struct net_device *dev);
  62static void vti6_dev_setup(struct net_device *dev);
  63static struct rtnl_link_ops vti6_link_ops __read_mostly;
  64
  65static unsigned int vti6_net_id __read_mostly;
  66struct vti6_net {
  67	/* the vti6 tunnel fallback device */
  68	struct net_device *fb_tnl_dev;
  69	/* lists for storing tunnels in use */
  70	struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE];
  71	struct ip6_tnl __rcu *tnls_wc[1];
  72	struct ip6_tnl __rcu **tnls[2];
  73};
  74
  75#define for_each_vti6_tunnel_rcu(start) \
  76	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
  77
  78/**
  79 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses
  80 *   @net: network namespace
  81 *   @remote: the address of the tunnel exit-point
  82 *   @local: the address of the tunnel entry-point
  83 *
  84 * Return:
  85 *   tunnel matching given end-points if found,
  86 *   else fallback tunnel if its device is up,
  87 *   else %NULL
  88 **/
  89static struct ip6_tnl *
  90vti6_tnl_lookup(struct net *net, const struct in6_addr *remote,
  91		const struct in6_addr *local)
  92{
  93	unsigned int hash = HASH(remote, local);
  94	struct ip6_tnl *t;
  95	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
  96	struct in6_addr any;
  97
  98	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
  99		if (ipv6_addr_equal(local, &t->parms.laddr) &&
 100		    ipv6_addr_equal(remote, &t->parms.raddr) &&
 101		    (t->dev->flags & IFF_UP))
 102			return t;
 103	}
 104
 105	memset(&any, 0, sizeof(any));
 106	hash = HASH(&any, local);
 107	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 108		if (ipv6_addr_equal(local, &t->parms.laddr) &&
 109		    (t->dev->flags & IFF_UP))
 110			return t;
 111	}
 112
 113	hash = HASH(remote, &any);
 114	for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 115		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
 116		    (t->dev->flags & IFF_UP))
 117			return t;
 118	}
 119
 120	t = rcu_dereference(ip6n->tnls_wc[0]);
 121	if (t && (t->dev->flags & IFF_UP))
 122		return t;
 123
 124	return NULL;
 125}
 126
 127/**
 128 * vti6_tnl_bucket - get head of list matching given tunnel parameters
 129 *   @ip6n: the private data for ip6_vti in the netns
 130 *   @p: parameters containing tunnel end-points
 131 *
 132 * Description:
 133 *   vti6_tnl_bucket() returns the head of the list matching the
 134 *   &struct in6_addr entries laddr and raddr in @p.
 135 *
 136 * Return: head of IPv6 tunnel list
 137 **/
 138static struct ip6_tnl __rcu **
 139vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p)
 140{
 141	const struct in6_addr *remote = &p->raddr;
 142	const struct in6_addr *local = &p->laddr;
 143	unsigned int h = 0;
 144	int prio = 0;
 145
 146	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 147		prio = 1;
 148		h = HASH(remote, local);
 149	}
 150	return &ip6n->tnls[prio][h];
 151}
 152
 153static void
 154vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t)
 155{
 156	struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms);
 157
 158	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 159	rcu_assign_pointer(*tp, t);
 160}
 161
 162static void
 163vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
 164{
 165	struct ip6_tnl __rcu **tp;
 166	struct ip6_tnl *iter;
 167
 168	for (tp = vti6_tnl_bucket(ip6n, &t->parms);
 169	     (iter = rtnl_dereference(*tp)) != NULL;
 170	     tp = &iter->next) {
 171		if (t == iter) {
 172			rcu_assign_pointer(*tp, t->next);
 173			break;
 174		}
 175	}
 176}
 177
 178static int vti6_tnl_create2(struct net_device *dev)
 179{
 180	struct ip6_tnl *t = netdev_priv(dev);
 181	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
 182	int err;
 183
 184	dev->rtnl_link_ops = &vti6_link_ops;
 185	err = register_netdevice(dev);
 186	if (err < 0)
 187		goto out;
 188
 189	strcpy(t->parms.name, dev->name);
 190
 191	vti6_tnl_link(ip6n, t);
 192
 193	return 0;
 194
 195out:
 196	return err;
 197}
 198
 199static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 200{
 201	struct net_device *dev;
 202	struct ip6_tnl *t;
 203	char name[IFNAMSIZ];
 204	int err;
 205
 206	if (p->name[0]) {
 207		if (!dev_valid_name(p->name))
 208			goto failed;
 209		strscpy(name, p->name, IFNAMSIZ);
 210	} else {
 211		sprintf(name, "ip6_vti%%d");
 212	}
 213
 214	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup);
 215	if (!dev)
 216		goto failed;
 217
 218	dev_net_set(dev, net);
 219
 220	t = netdev_priv(dev);
 221	t->parms = *p;
 222	t->net = dev_net(dev);
 223
 224	err = vti6_tnl_create2(dev);
 225	if (err < 0)
 226		goto failed_free;
 227
 228	return t;
 229
 230failed_free:
 231	free_netdev(dev);
 232failed:
 233	return NULL;
 234}
 235
 236/**
 237 * vti6_locate - find or create tunnel matching given parameters
 238 *   @net: network namespace
 239 *   @p: tunnel parameters
 240 *   @create: != 0 if allowed to create new tunnel if no match found
 241 *
 242 * Description:
 243 *   vti6_locate() first tries to locate an existing tunnel
 244 *   based on @parms. If this is unsuccessful, but @create is set a new
 245 *   tunnel device is created and registered for use.
 246 *
 247 * Return:
 248 *   matching tunnel or NULL
 249 **/
 250static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p,
 251				   int create)
 252{
 253	const struct in6_addr *remote = &p->raddr;
 254	const struct in6_addr *local = &p->laddr;
 255	struct ip6_tnl __rcu **tp;
 256	struct ip6_tnl *t;
 257	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 258
 259	for (tp = vti6_tnl_bucket(ip6n, p);
 260	     (t = rtnl_dereference(*tp)) != NULL;
 261	     tp = &t->next) {
 262		if (ipv6_addr_equal(local, &t->parms.laddr) &&
 263		    ipv6_addr_equal(remote, &t->parms.raddr)) {
 264			if (create)
 265				return NULL;
 266
 267			return t;
 268		}
 269	}
 270	if (!create)
 271		return NULL;
 272	return vti6_tnl_create(net, p);
 273}
 274
 275/**
 276 * vti6_dev_uninit - tunnel device uninitializer
 277 *   @dev: the device to be destroyed
 278 *
 279 * Description:
 280 *   vti6_dev_uninit() removes tunnel from its list
 281 **/
 282static void vti6_dev_uninit(struct net_device *dev)
 283{
 284	struct ip6_tnl *t = netdev_priv(dev);
 285	struct vti6_net *ip6n = net_generic(t->net, vti6_net_id);
 286
 287	if (dev == ip6n->fb_tnl_dev)
 288		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 289	else
 290		vti6_tnl_unlink(ip6n, t);
 291	netdev_put(dev, &t->dev_tracker);
 292}
 293
 294static int vti6_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
 295			    int encap_type)
 296{
 297	struct ip6_tnl *t;
 298	const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 299
 300	rcu_read_lock();
 301	t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
 302	if (t) {
 303		if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
 304			rcu_read_unlock();
 305			goto discard;
 306		}
 307
 308		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 309			rcu_read_unlock();
 310			goto discard;
 311		}
 312
 313		ipv6h = ipv6_hdr(skb);
 314		if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 315			DEV_STATS_INC(t->dev, rx_dropped);
 316			rcu_read_unlock();
 317			goto discard;
 318		}
 319
 320		rcu_read_unlock();
 321
 322		XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
 323		XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
 324		XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
 325		return xfrm_input(skb, nexthdr, spi, encap_type);
 326	}
 327	rcu_read_unlock();
 328	return -EINVAL;
 329discard:
 330	kfree_skb(skb);
 331	return 0;
 332}
 333
 334static int vti6_rcv(struct sk_buff *skb)
 335{
 336	int nexthdr = skb_network_header(skb)[IP6CB(skb)->nhoff];
 337
 338	return vti6_input_proto(skb, nexthdr, 0, 0);
 339}
 340
 341static int vti6_rcv_cb(struct sk_buff *skb, int err)
 342{
 343	unsigned short family;
 344	struct net_device *dev;
 345	struct xfrm_state *x;
 346	const struct xfrm_mode *inner_mode;
 347	struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
 348	u32 orig_mark = skb->mark;
 349	int ret;
 350
 351	if (!t)
 352		return 1;
 353
 354	dev = t->dev;
 355
 356	if (err) {
 357		DEV_STATS_INC(dev, rx_errors);
 358		DEV_STATS_INC(dev, rx_dropped);
 359
 360		return 0;
 361	}
 362
 363	x = xfrm_input_state(skb);
 364
 365	inner_mode = &x->inner_mode;
 366
 367	if (x->sel.family == AF_UNSPEC) {
 368		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 369		if (inner_mode == NULL) {
 370			XFRM_INC_STATS(dev_net(skb->dev),
 371				       LINUX_MIB_XFRMINSTATEMODEERROR);
 372			return -EINVAL;
 373		}
 374	}
 375
 376	family = inner_mode->family;
 377
 378	skb->mark = be32_to_cpu(t->parms.i_key);
 379	ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
 380	skb->mark = orig_mark;
 381
 382	if (!ret)
 383		return -EPERM;
 384
 385	skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));
 386	skb->dev = dev;
 387	dev_sw_netstats_rx_add(dev, skb->len);
 388
 389	return 0;
 390}
 391
 392/**
 393 * vti6_addr_conflict - compare packet addresses to tunnel's own
 394 *   @t: the outgoing tunnel device
 395 *   @hdr: IPv6 header from the incoming packet
 396 *
 397 * Description:
 398 *   Avoid trivial tunneling loop by checking that tunnel exit-point
 399 *   doesn't match source of incoming packet.
 400 *
 401 * Return:
 402 *   1 if conflict,
 403 *   0 else
 404 **/
 405static inline bool
 406vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 407{
 408	return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 409}
 410
 411static bool vti6_state_check(const struct xfrm_state *x,
 412			     const struct in6_addr *dst,
 413			     const struct in6_addr *src)
 414{
 415	xfrm_address_t *daddr = (xfrm_address_t *)dst;
 416	xfrm_address_t *saddr = (xfrm_address_t *)src;
 417
 418	/* if there is no transform then this tunnel is not functional.
 419	 * Or if the xfrm is not mode tunnel.
 420	 */
 421	if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
 422	    x->props.family != AF_INET6)
 423		return false;
 424
 425	if (ipv6_addr_any(dst))
 426		return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6);
 427
 428	if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6))
 429		return false;
 430
 431	return true;
 432}
 433
 434/**
 435 * vti6_xmit - send a packet
 436 *   @skb: the outgoing socket buffer
 437 *   @dev: the outgoing tunnel device
 438 *   @fl: the flow informations for the xfrm_lookup
 439 **/
 440static int
 441vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 442{
 443	struct ip6_tnl *t = netdev_priv(dev);
 444	struct dst_entry *dst = skb_dst(skb);
 445	struct net_device *tdev;
 446	struct xfrm_state *x;
 447	int pkt_len = skb->len;
 448	int err = -1;
 449	int mtu;
 450
 451	if (!dst) {
 452		switch (skb->protocol) {
 453		case htons(ETH_P_IP): {
 454			struct rtable *rt;
 455
 456			fl->u.ip4.flowi4_oif = dev->ifindex;
 457			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 458			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
 459			if (IS_ERR(rt))
 460				goto tx_err_link_failure;
 461			dst = &rt->dst;
 462			skb_dst_set(skb, dst);
 463			break;
 464		}
 465		case htons(ETH_P_IPV6):
 466			fl->u.ip6.flowi6_oif = dev->ifindex;
 467			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
 468			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
 469			if (dst->error) {
 470				dst_release(dst);
 471				dst = NULL;
 472				goto tx_err_link_failure;
 473			}
 474			skb_dst_set(skb, dst);
 475			break;
 476		default:
 477			goto tx_err_link_failure;
 478		}
 479	}
 480
 481	dst_hold(dst);
 482	dst = xfrm_lookup_route(t->net, dst, fl, NULL, 0);
 483	if (IS_ERR(dst)) {
 484		err = PTR_ERR(dst);
 485		dst = NULL;
 486		goto tx_err_link_failure;
 487	}
 488
 489	if (dst->flags & DST_XFRM_QUEUE)
 490		goto xmit;
 491
 492	x = dst->xfrm;
 493	if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr))
 494		goto tx_err_link_failure;
 495
 496	if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr,
 497			      (const struct in6_addr *)&x->id.daddr))
 498		goto tx_err_link_failure;
 499
 500	tdev = dst_dev(dst);
 501
 502	if (tdev == dev) {
 503		DEV_STATS_INC(dev, collisions);
 504		net_warn_ratelimited("%s: Local routing loop detected!\n",
 505				     t->parms.name);
 506		goto tx_err_dst_release;
 507	}
 508
 509	mtu = dst_mtu(dst);
 510	if (skb->len > mtu) {
 511		skb_dst_update_pmtu_no_confirm(skb, mtu);
 512
 513		if (skb->protocol == htons(ETH_P_IPV6)) {
 514			if (mtu < IPV6_MIN_MTU)
 515				mtu = IPV6_MIN_MTU;
 516
 517			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 518		} else {
 519			if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
 520				goto xmit;
 521			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 522				      htonl(mtu));
 523		}
 524
 525		err = -EMSGSIZE;
 526		goto tx_err_dst_release;
 527	}
 528
 529xmit:
 530	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
 531	skb_dst_set(skb, dst);
 532	skb->dev = dst_dev(dst);
 533
 534	err = dst_output(t->net, skb->sk, skb);
 535	if (net_xmit_eval(err) == 0)
 536		err = pkt_len;
 537	iptunnel_xmit_stats(dev, err);
 538
 539	return 0;
 540tx_err_link_failure:
 541	DEV_STATS_INC(dev, tx_carrier_errors);
 542	dst_link_failure(skb);
 543tx_err_dst_release:
 544	dst_release(dst);
 545	return err;
 546}
 547
 548static netdev_tx_t
 549vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 550{
 551	struct ip6_tnl *t = netdev_priv(dev);
 552	struct flowi fl;
 553	int ret;
 554
 555	if (!pskb_inet_may_pull(skb))
 556		goto tx_err;
 557
 558	memset(&fl, 0, sizeof(fl));
 559
 560	switch (skb->protocol) {
 561	case htons(ETH_P_IPV6):
 562		if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
 563		    vti6_addr_conflict(t, ipv6_hdr(skb)))
 564			goto tx_err;
 565
 566		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
 567		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6);
 568		break;
 569	case htons(ETH_P_IP):
 570		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 571		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET);
 572		break;
 573	default:
 574		goto tx_err;
 575	}
 576
 577	/* override mark with tunnel output key */
 578	fl.flowi_mark = be32_to_cpu(t->parms.o_key);
 579
 580	ret = vti6_xmit(skb, dev, &fl);
 581	if (ret < 0)
 582		goto tx_err;
 583
 584	return NETDEV_TX_OK;
 585
 586tx_err:
 587	DEV_STATS_INC(dev, tx_errors);
 588	DEV_STATS_INC(dev, tx_dropped);
 589	kfree_skb(skb);
 590	return NETDEV_TX_OK;
 591}
 592
 593static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 594		    u8 type, u8 code, int offset, __be32 info)
 595{
 596	__be32 spi;
 597	__u32 mark;
 598	struct xfrm_state *x;
 599	struct ip6_tnl *t;
 600	struct ip_esp_hdr *esph;
 601	struct ip_auth_hdr *ah;
 602	struct ip_comp_hdr *ipch;
 603	struct net *net = dev_net(skb->dev);
 604	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
 605	int protocol = iph->nexthdr;
 606
 607	t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr);
 608	if (!t)
 609		return -1;
 610
 611	mark = be32_to_cpu(t->parms.o_key);
 612
 613	switch (protocol) {
 614	case IPPROTO_ESP:
 615		esph = (struct ip_esp_hdr *)(skb->data + offset);
 616		spi = esph->spi;
 617		break;
 618	case IPPROTO_AH:
 619		ah = (struct ip_auth_hdr *)(skb->data + offset);
 620		spi = ah->spi;
 621		break;
 622	case IPPROTO_COMP:
 623		ipch = (struct ip_comp_hdr *)(skb->data + offset);
 624		spi = htonl(ntohs(ipch->cpi));
 625		break;
 626	default:
 627		return 0;
 628	}
 629
 630	if (type != ICMPV6_PKT_TOOBIG &&
 631	    type != NDISC_REDIRECT)
 632		return 0;
 633
 634	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 635			      spi, protocol, AF_INET6);
 636	if (!x)
 637		return 0;
 638
 639	if (type == NDISC_REDIRECT)
 640		ip6_redirect(skb, net, skb->dev->ifindex, 0,
 641			     sock_net_uid(net, NULL));
 642	else
 643		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
 644	xfrm_state_put(x);
 645
 646	return 0;
 647}
 648
 649static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu)
 650{
 651	struct net_device *dev = t->dev;
 652	struct __ip6_tnl_parm *p = &t->parms;
 653	struct net_device *tdev = NULL;
 654	int mtu;
 655
 656	__dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
 657	memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
 658
 659	p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV |
 660		      IP6_TNL_F_CAP_PER_PACKET);
 661	p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
 662
 663	if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV)
 664		dev->flags |= IFF_POINTOPOINT;
 665	else
 666		dev->flags &= ~IFF_POINTOPOINT;
 667
 668	if (keep_mtu && dev->mtu) {
 669		WRITE_ONCE(dev->mtu,
 670			   clamp(dev->mtu, dev->min_mtu, dev->max_mtu));
 671		return;
 672	}
 673
 674	if (p->flags & IP6_TNL_F_CAP_XMIT) {
 675		int strict = (ipv6_addr_type(&p->raddr) &
 676			      (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
 677		struct rt6_info *rt = rt6_lookup(t->net,
 678						 &p->raddr, &p->laddr,
 679						 p->link, NULL, strict);
 680
 681		if (rt)
 682			tdev = rt->dst.dev;
 683		ip6_rt_put(rt);
 684	}
 685
 686	if (!tdev && p->link)
 687		tdev = __dev_get_by_index(t->net, p->link);
 688
 689	if (tdev)
 690		mtu = tdev->mtu - sizeof(struct ipv6hdr);
 691	else
 692		mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr);
 693
 694	dev->mtu = max_t(int, mtu, IPV4_MIN_MTU);
 695}
 696
 697/**
 698 * vti6_tnl_change - update the tunnel parameters
 699 *   @t: tunnel to be changed
 700 *   @p: tunnel configuration parameters
 701 *   @keep_mtu: MTU was set from userspace, don't re-compute it
 702 *
 703 * Description:
 704 *   vti6_tnl_change() updates the tunnel parameters
 705 **/
 706static int
 707vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p,
 708		bool keep_mtu)
 709{
 710	t->parms.laddr = p->laddr;
 711	t->parms.raddr = p->raddr;
 712	t->parms.link = p->link;
 713	t->parms.i_key = p->i_key;
 714	t->parms.o_key = p->o_key;
 715	t->parms.proto = p->proto;
 716	t->parms.fwmark = p->fwmark;
 717	dst_cache_reset(&t->dst_cache);
 718	vti6_link_config(t, keep_mtu);
 719	return 0;
 720}
 721
 722static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p,
 723		       bool keep_mtu)
 724{
 725	struct net *net = dev_net(t->dev);
 726	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 727	int err;
 728
 729	vti6_tnl_unlink(ip6n, t);
 730	synchronize_net();
 731	err = vti6_tnl_change(t, p, keep_mtu);
 732	vti6_tnl_link(ip6n, t);
 733	netdev_state_change(t->dev);
 734	return err;
 735}
 736
 737static void
 738vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u)
 739{
 740	p->laddr = u->laddr;
 741	p->raddr = u->raddr;
 742	p->link = u->link;
 743	p->i_key = u->i_key;
 744	p->o_key = u->o_key;
 745	p->proto = u->proto;
 746
 747	memcpy(p->name, u->name, sizeof(u->name));
 748}
 749
 750static void
 751vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p)
 752{
 753	u->laddr = p->laddr;
 754	u->raddr = p->raddr;
 755	u->link = p->link;
 756	u->i_key = p->i_key;
 757	u->o_key = p->o_key;
 758	if (u->i_key)
 759		u->i_flags |= GRE_KEY;
 760	if (u->o_key)
 761		u->o_flags |= GRE_KEY;
 762	u->proto = p->proto;
 763
 764	memcpy(u->name, p->name, sizeof(u->name));
 765}
 766
 767/**
 768 * vti6_siocdevprivate - configure vti6 tunnels from userspace
 769 *   @dev: virtual device associated with tunnel
 770 *   @ifr: unused
 771 *   @data: parameters passed from userspace
 772 *   @cmd: command to be performed
 773 *
 774 * Description:
 775 *   vti6_siocdevprivate() is used for managing vti6 tunnels
 776 *   from userspace.
 777 *
 778 *   The possible commands are the following:
 779 *     %SIOCGETTUNNEL: get tunnel parameters for device
 780 *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
 781 *     %SIOCCHGTUNNEL: change tunnel parameters to those given
 782 *     %SIOCDELTUNNEL: delete tunnel
 783 *
 784 *   The fallback device "ip6_vti0", created during module
 785 *   initialization, can be used for creating other tunnel devices.
 786 *
 787 * Return:
 788 *   0 on success,
 789 *   %-EFAULT if unable to copy data to or from userspace,
 790 *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
 791 *   %-EINVAL if passed tunnel parameters are invalid,
 792 *   %-EEXIST if changing a tunnel's parameters would cause a conflict
 793 *   %-ENODEV if attempting to change or delete a nonexisting device
 794 **/
 795static int
 796vti6_siocdevprivate(struct net_device *dev, struct ifreq *ifr, void __user *data, int cmd)
 797{
 798	int err = 0;
 799	struct ip6_tnl_parm2 p;
 800	struct __ip6_tnl_parm p1;
 801	struct ip6_tnl *t = NULL;
 802	struct net *net = dev_net(dev);
 803	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 804
 805	memset(&p1, 0, sizeof(p1));
 806
 807	switch (cmd) {
 808	case SIOCGETTUNNEL:
 809		if (dev == ip6n->fb_tnl_dev) {
 810			if (copy_from_user(&p, data, sizeof(p))) {
 811				err = -EFAULT;
 812				break;
 813			}
 814			vti6_parm_from_user(&p1, &p);
 815			t = vti6_locate(net, &p1, 0);
 816		} else {
 817			memset(&p, 0, sizeof(p));
 818		}
 819		if (!t)
 820			t = netdev_priv(dev);
 821		vti6_parm_to_user(&p, &t->parms);
 822		if (copy_to_user(data, &p, sizeof(p)))
 823			err = -EFAULT;
 824		break;
 825	case SIOCADDTUNNEL:
 826	case SIOCCHGTUNNEL:
 827		err = -EPERM;
 828		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 829			break;
 830		err = -EFAULT;
 831		if (copy_from_user(&p, data, sizeof(p)))
 832			break;
 833		err = -EINVAL;
 834		if (p.proto != IPPROTO_IPV6  && p.proto != 0)
 835			break;
 836		vti6_parm_from_user(&p1, &p);
 837		t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL);
 838		if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
 839			if (t) {
 840				if (t->dev != dev) {
 841					err = -EEXIST;
 842					break;
 843				}
 844			} else
 845				t = netdev_priv(dev);
 846
 847			err = vti6_update(t, &p1, false);
 848		}
 849		if (t) {
 850			err = 0;
 851			vti6_parm_to_user(&p, &t->parms);
 852			if (copy_to_user(data, &p, sizeof(p)))
 853				err = -EFAULT;
 854
 855		} else
 856			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 857		break;
 858	case SIOCDELTUNNEL:
 859		err = -EPERM;
 860		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 861			break;
 862
 863		if (dev == ip6n->fb_tnl_dev) {
 864			err = -EFAULT;
 865			if (copy_from_user(&p, data, sizeof(p)))
 866				break;
 867			err = -ENOENT;
 868			vti6_parm_from_user(&p1, &p);
 869			t = vti6_locate(net, &p1, 0);
 870			if (!t)
 871				break;
 872			err = -EPERM;
 873			if (t->dev == ip6n->fb_tnl_dev)
 874				break;
 875			dev = t->dev;
 876		}
 877		err = 0;
 878		unregister_netdevice(dev);
 879		break;
 880	default:
 881		err = -EINVAL;
 882	}
 883	return err;
 884}
 885
 886static const struct net_device_ops vti6_netdev_ops = {
 887	.ndo_init	= vti6_dev_init,
 888	.ndo_uninit	= vti6_dev_uninit,
 889	.ndo_start_xmit = vti6_tnl_xmit,
 890	.ndo_siocdevprivate = vti6_siocdevprivate,
 891	.ndo_get_iflink = ip6_tnl_get_iflink,
 892};
 893
 894/**
 895 * vti6_dev_setup - setup virtual tunnel device
 896 *   @dev: virtual device associated with tunnel
 897 *
 898 * Description:
 899 *   Initialize function pointers and device parameters
 900 **/
 901static void vti6_dev_setup(struct net_device *dev)
 902{
 903	dev->netdev_ops = &vti6_netdev_ops;
 904	dev->header_ops = &ip_tunnel_header_ops;
 905	dev->needs_free_netdev = true;
 906
 907	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 908	dev->type = ARPHRD_TUNNEL6;
 909	dev->min_mtu = IPV4_MIN_MTU;
 910	dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);
 911	dev->flags |= IFF_NOARP;
 912	dev->addr_len = sizeof(struct in6_addr);
 913	netif_keep_dst(dev);
 914	/* This perm addr will be used as interface identifier by IPv6 */
 915	dev->addr_assign_type = NET_ADDR_RANDOM;
 916	eth_random_addr(dev->perm_addr);
 917}
 918
 919/**
 920 * vti6_dev_init_gen - general initializer for all tunnel devices
 921 *   @dev: virtual device associated with tunnel
 922 **/
 923static inline int vti6_dev_init_gen(struct net_device *dev)
 924{
 925	struct ip6_tnl *t = netdev_priv(dev);
 926
 927	t->dev = dev;
 928	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
 929	netdev_lockdep_set_classes(dev);
 930	return 0;
 931}
 932
 933/**
 934 * vti6_dev_init - initializer for all non fallback tunnel devices
 935 *   @dev: virtual device associated with tunnel
 936 **/
 937static int vti6_dev_init(struct net_device *dev)
 938{
 939	struct ip6_tnl *t = netdev_priv(dev);
 940	int err = vti6_dev_init_gen(dev);
 941
 942	if (err)
 943		return err;
 944	vti6_link_config(t, true);
 945	return 0;
 946}
 947
 948/**
 949 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device
 950 *   @dev: fallback device
 951 *
 952 * Return: 0
 953 **/
 954static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev)
 955{
 956	struct ip6_tnl *t = netdev_priv(dev);
 957	struct net *net = dev_net(dev);
 958	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 959
 960	t->net = net;
 961	t->parms.proto = IPPROTO_IPV6;
 962
 963	rcu_assign_pointer(ip6n->tnls_wc[0], t);
 964	return 0;
 965}
 966
 967static int vti6_validate(struct nlattr *tb[], struct nlattr *data[],
 968			 struct netlink_ext_ack *extack)
 969{
 970	return 0;
 971}
 972
 973static void vti6_netlink_parms(struct nlattr *data[],
 974			       struct __ip6_tnl_parm *parms)
 975{
 976	memset(parms, 0, sizeof(*parms));
 977
 978	if (!data)
 979		return;
 980
 981	if (data[IFLA_VTI_LINK])
 982		parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
 983
 984	if (data[IFLA_VTI_LOCAL])
 985		parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]);
 986
 987	if (data[IFLA_VTI_REMOTE])
 988		parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]);
 989
 990	if (data[IFLA_VTI_IKEY])
 991		parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
 992
 993	if (data[IFLA_VTI_OKEY])
 994		parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
 995
 996	if (data[IFLA_VTI_FWMARK])
 997		parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 998}
 999
1000static int vti6_newlink(struct net_device *dev,
1001			struct rtnl_newlink_params *params,
1002			struct netlink_ext_ack *extack)
1003{
1004	struct nlattr **data = params->data;
1005	struct ip6_tnl *nt;
1006	struct net *net;
1007
1008	net = params->link_net ? : dev_net(dev);
1009	nt = netdev_priv(dev);
1010	vti6_netlink_parms(data, &nt->parms);
1011
1012	nt->parms.proto = IPPROTO_IPV6;
1013	nt->net = net;
1014
1015	if (vti6_locate(net, &nt->parms, 0))
1016		return -EEXIST;
1017
1018	return vti6_tnl_create2(dev);
1019}
1020
1021static void vti6_dellink(struct net_device *dev, struct list_head *head)
1022{
1023	struct net *net = dev_net(dev);
1024	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1025
1026	if (dev != ip6n->fb_tnl_dev)
1027		unregister_netdevice_queue(dev, head);
1028}
1029
1030static int vti6_changelink(struct net_device *dev, struct nlattr *tb[],
1031			   struct nlattr *data[],
1032			   struct netlink_ext_ack *extack)
1033{
1034	struct ip6_tnl *t;
1035	struct __ip6_tnl_parm p;
1036	struct net *net = dev_net(dev);
1037	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1038
1039	if (dev == ip6n->fb_tnl_dev)
1040		return -EINVAL;
1041
1042	vti6_netlink_parms(data, &p);
1043
1044	t = vti6_locate(net, &p, 0);
1045
1046	if (t) {
1047		if (t->dev != dev)
1048			return -EEXIST;
1049	} else
1050		t = netdev_priv(dev);
1051
1052	return vti6_update(t, &p, tb && tb[IFLA_MTU]);
1053}
1054
1055static size_t vti6_get_size(const struct net_device *dev)
1056{
1057	return
1058		/* IFLA_VTI_LINK */
1059		nla_total_size(4) +
1060		/* IFLA_VTI_LOCAL */
1061		nla_total_size(sizeof(struct in6_addr)) +
1062		/* IFLA_VTI_REMOTE */
1063		nla_total_size(sizeof(struct in6_addr)) +
1064		/* IFLA_VTI_IKEY */
1065		nla_total_size(4) +
1066		/* IFLA_VTI_OKEY */
1067		nla_total_size(4) +
1068		/* IFLA_VTI_FWMARK */
1069		nla_total_size(4) +
1070		0;
1071}
1072
1073static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1074{
1075	struct ip6_tnl *tunnel = netdev_priv(dev);
1076	struct __ip6_tnl_parm *parm = &tunnel->parms;
1077
1078	if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) ||
1079	    nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) ||
1080	    nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) ||
1081	    nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) ||
1082	    nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) ||
1083	    nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark))
1084		goto nla_put_failure;
1085	return 0;
1086
1087nla_put_failure:
1088	return -EMSGSIZE;
1089}
1090
1091static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = {
1092	[IFLA_VTI_LINK]		= { .type = NLA_U32 },
1093	[IFLA_VTI_LOCAL]	= { .len = sizeof(struct in6_addr) },
1094	[IFLA_VTI_REMOTE]	= { .len = sizeof(struct in6_addr) },
1095	[IFLA_VTI_IKEY]		= { .type = NLA_U32 },
1096	[IFLA_VTI_OKEY]		= { .type = NLA_U32 },
1097	[IFLA_VTI_FWMARK]	= { .type = NLA_U32 },
1098};
1099
1100static struct rtnl_link_ops vti6_link_ops __read_mostly = {
1101	.kind		= "vti6",
1102	.maxtype	= IFLA_VTI_MAX,
1103	.policy		= vti6_policy,
1104	.priv_size	= sizeof(struct ip6_tnl),
1105	.setup		= vti6_dev_setup,
1106	.validate	= vti6_validate,
1107	.newlink	= vti6_newlink,
1108	.dellink	= vti6_dellink,
1109	.changelink	= vti6_changelink,
1110	.get_size	= vti6_get_size,
1111	.fill_info	= vti6_fill_info,
1112	.get_link_net	= ip6_tnl_get_link_net,
1113};
1114
1115static void __net_exit vti6_exit_rtnl_net(struct net *net, struct list_head *list)
1116{
1117	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1118	struct ip6_tnl *t;
1119	int h;
1120
1121	for (h = 0; h < IP6_VTI_HASH_SIZE; h++) {
1122		t = rtnl_net_dereference(net, ip6n->tnls_r_l[h]);
1123		while (t) {
1124			unregister_netdevice_queue(t->dev, list);
1125			t = rtnl_net_dereference(net, t->next);
1126		}
1127	}
1128
1129	t = rtnl_net_dereference(net, ip6n->tnls_wc[0]);
1130	if (t)
1131		unregister_netdevice_queue(t->dev, list);
1132}
1133
1134static int __net_init vti6_init_net(struct net *net)
1135{
1136	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
1137	struct ip6_tnl *t = NULL;
1138	int err;
1139
1140	ip6n->tnls[0] = ip6n->tnls_wc;
1141	ip6n->tnls[1] = ip6n->tnls_r_l;
1142
1143	if (!net_has_fallback_tunnels(net))
1144		return 0;
1145	err = -ENOMEM;
1146	ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0",
1147					NET_NAME_UNKNOWN, vti6_dev_setup);
1148
1149	if (!ip6n->fb_tnl_dev)
1150		goto err_alloc_dev;
1151	dev_net_set(ip6n->fb_tnl_dev, net);
1152	ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops;
1153
1154	err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1155	if (err < 0)
1156		goto err_register;
1157
1158	err = register_netdev(ip6n->fb_tnl_dev);
1159	if (err < 0)
1160		goto err_register;
1161
1162	t = netdev_priv(ip6n->fb_tnl_dev);
1163
1164	strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1165	return 0;
1166
1167err_register:
1168	free_netdev(ip6n->fb_tnl_dev);
1169err_alloc_dev:
1170	return err;
1171}
1172
1173static struct pernet_operations vti6_net_ops = {
1174	.init = vti6_init_net,
1175	.exit_rtnl = vti6_exit_rtnl_net,
1176	.id   = &vti6_net_id,
1177	.size = sizeof(struct vti6_net),
1178};
1179
1180static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {
1181	.handler	=	vti6_rcv,
1182	.input_handler	=	vti6_input_proto,
1183	.cb_handler	=	vti6_rcv_cb,
1184	.err_handler	=	vti6_err,
1185	.priority	=	100,
1186};
1187
1188static struct xfrm6_protocol vti_ah6_protocol __read_mostly = {
1189	.handler	=	vti6_rcv,
1190	.input_handler	=	vti6_input_proto,
1191	.cb_handler	=	vti6_rcv_cb,
1192	.err_handler	=	vti6_err,
1193	.priority	=	100,
1194};
1195
1196static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = {
1197	.handler	=	vti6_rcv,
1198	.input_handler	=	vti6_input_proto,
1199	.cb_handler	=	vti6_rcv_cb,
1200	.err_handler	=	vti6_err,
1201	.priority	=	100,
1202};
1203
1204#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1205static int vti6_rcv_tunnel(struct sk_buff *skb)
1206{
1207	const xfrm_address_t *saddr;
1208	__be32 spi;
1209
1210	saddr = (const xfrm_address_t *)&ipv6_hdr(skb)->saddr;
1211	spi = xfrm6_tunnel_spi_lookup(dev_net(skb->dev), saddr);
1212
1213	return vti6_input_proto(skb, IPPROTO_IPV6, spi, 0);
1214}
1215
1216static struct xfrm6_tunnel vti_ipv6_handler __read_mostly = {
1217	.handler	=	vti6_rcv_tunnel,
1218	.cb_handler	=	vti6_rcv_cb,
1219	.err_handler	=	vti6_err,
1220	.priority	=	0,
1221};
1222
1223static struct xfrm6_tunnel vti_ip6ip_handler __read_mostly = {
1224	.handler	=	vti6_rcv_tunnel,
1225	.cb_handler	=	vti6_rcv_cb,
1226	.err_handler	=	vti6_err,
1227	.priority	=	0,
1228};
1229#endif
1230
1231/**
1232 * vti6_tunnel_init - register protocol and reserve needed resources
1233 *
1234 * Return: 0 on success
1235 **/
1236static int __init vti6_tunnel_init(void)
1237{
1238	const char *msg;
1239	int err;
1240
1241	msg = "tunnel device";
1242	err = register_pernet_device(&vti6_net_ops);
1243	if (err < 0)
1244		goto pernet_dev_failed;
1245
1246	msg = "tunnel protocols";
1247	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
1248	if (err < 0)
1249		goto xfrm_proto_esp_failed;
1250	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
1251	if (err < 0)
1252		goto xfrm_proto_ah_failed;
1253	err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP);
1254	if (err < 0)
1255		goto xfrm_proto_comp_failed;
1256#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1257	msg = "ipv6 tunnel";
1258	err = xfrm6_tunnel_register(&vti_ipv6_handler, AF_INET6);
1259	if (err < 0)
1260		goto vti_tunnel_ipv6_failed;
1261	err = xfrm6_tunnel_register(&vti_ip6ip_handler, AF_INET);
1262	if (err < 0)
1263		goto vti_tunnel_ip6ip_failed;
1264#endif
1265
1266	msg = "netlink interface";
1267	err = rtnl_link_register(&vti6_link_ops);
1268	if (err < 0)
1269		goto rtnl_link_failed;
1270
1271	return 0;
1272
1273rtnl_link_failed:
1274#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1275	err = xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET);
1276vti_tunnel_ip6ip_failed:
1277	err = xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6);
1278vti_tunnel_ipv6_failed:
1279#endif
1280	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1281xfrm_proto_comp_failed:
1282	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1283xfrm_proto_ah_failed:
1284	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1285xfrm_proto_esp_failed:
1286	unregister_pernet_device(&vti6_net_ops);
1287pernet_dev_failed:
1288	pr_err("vti6 init: failed to register %s\n", msg);
1289	return err;
1290}
1291
1292/**
1293 * vti6_tunnel_cleanup - free resources and unregister protocol
1294 **/
1295static void __exit vti6_tunnel_cleanup(void)
1296{
1297	rtnl_link_unregister(&vti6_link_ops);
1298#if IS_REACHABLE(CONFIG_INET6_XFRM_TUNNEL)
1299	xfrm6_tunnel_deregister(&vti_ip6ip_handler, AF_INET);
1300	xfrm6_tunnel_deregister(&vti_ipv6_handler, AF_INET6);
1301#endif
1302	xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP);
1303	xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
1304	xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
1305	unregister_pernet_device(&vti6_net_ops);
1306}
1307
1308module_init(vti6_tunnel_init);
1309module_exit(vti6_tunnel_cleanup);
1310MODULE_LICENSE("GPL");
1311MODULE_ALIAS_RTNL_LINK("vti6");
1312MODULE_ALIAS_NETDEV("ip6_vti0");
1313MODULE_AUTHOR("Steffen Klassert");
1314MODULE_DESCRIPTION("IPv6 virtual tunnel interface");