net/ipv6/ip6_tunnel.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      IPv6 tunneling device
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   8  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   9  *
  10  *      Based on:
  11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  12  *
  13  *      RFC 2473
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/capability.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/sockios.h>
  23 #include <linux/icmp.h>
  24 #include <linux/if.h>
  25 #include <linux/in.h>
  26 #include <linux/ip.h>
  27 #include <linux/net.h>
  28 #include <linux/in6.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/icmpv6.h>
  32 #include <linux/init.h>
  33 #include <linux/route.h>
  34 #include <linux/rtnetlink.h>
  35 #include <linux/netfilter_ipv6.h>
  36 #include <linux/slab.h>
  37 #include <linux/hash.h>
  38 #include <linux/etherdevice.h>
  39
  40 #include <linux/uaccess.h>
  41 #include <linux/atomic.h>
  42
  43 #include <net/icmp.h>
  44 #include <net/ip.h>
  45 #include <net/ip_tunnels.h>
  46 #include <net/ipv6.h>
  47 #include <net/ip6_route.h>
  48 #include <net/addrconf.h>
  49 #include <net/ip6_tunnel.h>
  50 #include <net/xfrm.h>
  51 #include <net/dsfield.h>
  52 #include <net/inet_ecn.h>
  53 #include <net/net_namespace.h>
  54 #include <net/netns/generic.h>
  55 #include <net/dst_metadata.h>
  56
  57 MODULE_AUTHOR("Ville Nuorvala");
  58 MODULE_DESCRIPTION("IPv6 tunneling device");
  59 MODULE_LICENSE("GPL");
  60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
  61 MODULE_ALIAS_NETDEV("ip6tnl0");
  62
  63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
  64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
  65
  66 static bool log_ecn_error = true;
  67 module_param(log_ecn_error, bool, 0644);
  68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  69
  70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  71 {
  72         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  73
  74         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
  75 }
  76
  77 static int ip6_tnl_dev_init(struct net_device *dev);
  78 static void ip6_tnl_dev_setup(struct net_device *dev);
  79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  80
  81 static unsigned int ip6_tnl_net_id __read_mostly;
  82 struct ip6_tnl_net {
  83         /* the IPv6 tunnel fallback device */
  84         struct net_device *fb_tnl_dev;
  85         /* lists for storing tunnels in use */
  86         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
  87         struct ip6_tnl __rcu *tnls_wc[1];
  88         struct ip6_tnl __rcu **tnls[2];
  89         struct ip6_tnl __rcu *collect_md_tun;
  90 };
  91
  92 static inline int ip6_tnl_mpls_supported(void)
  93 {
  94         return IS_ENABLED(CONFIG_MPLS);
  95 }
  96
  97 #define for_each_ip6_tunnel_rcu(start) \
  98         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
  99
 100 /**
 101  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 102  *   @net: network namespace
 103  *   @link: ifindex of underlying interface
 104  *   @remote: the address of the tunnel exit-point
 105  *   @local: the address of the tunnel entry-point
 106  *
 107  * Return:
 108  *   tunnel matching given end-points if found,
 109  *   else fallback tunnel if its device is up,
 110  *   else %NULL
 111  **/
 112
 113 static struct ip6_tnl *
 114 ip6_tnl_lookup(struct net *net, int link,
 115                const struct in6_addr *remote, const struct in6_addr *local)
 116 {
 117         unsigned int hash = HASH(remote, local);
 118         struct ip6_tnl *t, *cand = NULL;
 119         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 120         struct in6_addr any;
 121
 122         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 123                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 124                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 125                     !(t->dev->flags & IFF_UP))
 126                         continue;
 127
 128                 if (link == t->parms.link)
 129                         return t;
 130                 else
 131                         cand = t;
 132         }
 133
 134         memset(&any, 0, sizeof(any));
 135         hash = HASH(&any, local);
 136         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 137                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 138                     !ipv6_addr_any(&t->parms.raddr) ||
 139                     !(t->dev->flags & IFF_UP))
 140                         continue;
 141
 142                 if (link == t->parms.link)
 143                         return t;
 144                 else if (!cand)
 145                         cand = t;
 146         }
 147
 148         hash = HASH(remote, &any);
 149         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 150                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 151                     !ipv6_addr_any(&t->parms.laddr) ||
 152                     !(t->dev->flags & IFF_UP))
 153                         continue;
 154
 155                 if (link == t->parms.link)
 156                         return t;
 157                 else if (!cand)
 158                         cand = t;
 159         }
 160
 161         if (cand)
 162                 return cand;
 163
 164         t = rcu_dereference(ip6n->collect_md_tun);
 165         if (t && t->dev->flags & IFF_UP)
 166                 return t;
 167
 168         t = rcu_dereference(ip6n->tnls_wc[0]);
 169         if (t && (t->dev->flags & IFF_UP))
 170                 return t;
 171
 172         return NULL;
 173 }
 174
 175 /**
 176  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 177  *   @ip6n: the private data for ip6_vti in the netns
 178  *   @p: parameters containing tunnel end-points
 179  *
 180  * Description:
 181  *   ip6_tnl_bucket() returns the head of the list matching the
 182  *   &struct in6_addr entries laddr and raddr in @p.
 183  *
 184  * Return: head of IPv6 tunnel list
 185  **/
 186
 187 static struct ip6_tnl __rcu **
 188 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 189 {
 190         const struct in6_addr *remote = &p->raddr;
 191         const struct in6_addr *local = &p->laddr;
 192         unsigned int h = 0;
 193         int prio = 0;
 194
 195         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 196                 prio = 1;
 197                 h = HASH(remote, local);
 198         }
 199         return &ip6n->tnls[prio][h];
 200 }
 201
 202 /**
 203  * ip6_tnl_link - add tunnel to hash table
 204  *   @ip6n: the private data for ip6_vti in the netns
 205  *   @t: tunnel to be added
 206  **/
 207
 208 static void
 209 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 210 {
 211         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 212
 213         if (t->parms.collect_md)
 214                 rcu_assign_pointer(ip6n->collect_md_tun, t);
 215         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 216         rcu_assign_pointer(*tp, t);
 217 }
 218
 219 /**
 220  * ip6_tnl_unlink - remove tunnel from hash table
 221  *   @ip6n: the private data for ip6_vti in the netns
 222  *   @t: tunnel to be removed
 223  **/
 224
 225 static void
 226 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 227 {
 228         struct ip6_tnl __rcu **tp;
 229         struct ip6_tnl *iter;
 230
 231         if (t->parms.collect_md)
 232                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
 233
 234         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 235              (iter = rtnl_dereference(*tp)) != NULL;
 236              tp = &iter->next) {
 237                 if (t == iter) {
 238                         rcu_assign_pointer(*tp, t->next);
 239                         break;
 240                 }
 241         }
 242 }
 243
 244 static void ip6_dev_free(struct net_device *dev)
 245 {
 246         struct ip6_tnl *t = netdev_priv(dev);
 247
 248         gro_cells_destroy(&t->gro_cells);
 249         dst_cache_destroy(&t->dst_cache);
 250         free_percpu(dev->tstats);
 251 }
 252
 253 static int ip6_tnl_create2(struct net_device *dev)
 254 {
 255         struct ip6_tnl *t = netdev_priv(dev);
 256         struct net *net = dev_net(dev);
 257         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 258         int err;
 259
 260         t = netdev_priv(dev);
 261
 262         dev->rtnl_link_ops = &ip6_link_ops;
 263         err = register_netdevice(dev);
 264         if (err < 0)
 265                 goto out;
 266
 267         strcpy(t->parms.name, dev->name);
 268
 269         ip6_tnl_link(ip6n, t);
 270         return 0;
 271
 272 out:
 273         return err;
 274 }
 275
 276 /**
 277  * ip6_tnl_create - create a new tunnel
 278  *   @net: network namespace
 279  *   @p: tunnel parameters
 280  *
 281  * Description:
 282  *   Create tunnel matching given parameters.
 283  *
 284  * Return:
 285  *   created tunnel or error pointer
 286  **/
 287
 288 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 289 {
 290         struct net_device *dev;
 291         struct ip6_tnl *t;
 292         char name[IFNAMSIZ];
 293         int err = -E2BIG;
 294
 295         if (p->name[0]) {
 296                 if (!dev_valid_name(p->name))
 297                         goto failed;
 298                 strlcpy(name, p->name, IFNAMSIZ);
 299         } else {
 300                 sprintf(name, "ip6tnl%%d");
 301         }
 302         err = -ENOMEM;
 303         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 304                            ip6_tnl_dev_setup);
 305         if (!dev)
 306                 goto failed;
 307
 308         dev_net_set(dev, net);
 309
 310         t = netdev_priv(dev);
 311         t->parms = *p;
 312         t->net = dev_net(dev);
 313         err = ip6_tnl_create2(dev);
 314         if (err < 0)
 315                 goto failed_free;
 316
 317         return t;
 318
 319 failed_free:
 320         free_netdev(dev);
 321 failed:
 322         return ERR_PTR(err);
 323 }
 324
 325 /**
 326  * ip6_tnl_locate - find or create tunnel matching given parameters
 327  *   @net: network namespace
 328  *   @p: tunnel parameters
 329  *   @create: != 0 if allowed to create new tunnel if no match found
 330  *
 331  * Description:
 332  *   ip6_tnl_locate() first tries to locate an existing tunnel
 333  *   based on @parms. If this is unsuccessful, but @create is set a new
 334  *   tunnel device is created and registered for use.
 335  *
 336  * Return:
 337  *   matching tunnel or error pointer
 338  **/
 339
 340 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 341                 struct __ip6_tnl_parm *p, int create)
 342 {
 343         const struct in6_addr *remote = &p->raddr;
 344         const struct in6_addr *local = &p->laddr;
 345         struct ip6_tnl __rcu **tp;
 346         struct ip6_tnl *t;
 347         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 348
 349         for (tp = ip6_tnl_bucket(ip6n, p);
 350              (t = rtnl_dereference(*tp)) != NULL;
 351              tp = &t->next) {
 352                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 353                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 354                     p->link == t->parms.link) {
 355                         if (create)
 356                                 return ERR_PTR(-EEXIST);
 357
 358                         return t;
 359                 }
 360         }
 361         if (!create)
 362                 return ERR_PTR(-ENODEV);
 363         return ip6_tnl_create(net, p);
 364 }
 365
 366 /**
 367  * ip6_tnl_dev_uninit - tunnel device uninitializer
 368  *   @dev: the device to be destroyed
 369  *
 370  * Description:
 371  *   ip6_tnl_dev_uninit() removes tunnel from its list
 372  **/
 373
 374 static void
 375 ip6_tnl_dev_uninit(struct net_device *dev)
 376 {
 377         struct ip6_tnl *t = netdev_priv(dev);
 378         struct net *net = t->net;
 379         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 380
 381         if (dev == ip6n->fb_tnl_dev)
 382                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 383         else
 384                 ip6_tnl_unlink(ip6n, t);
 385         dst_cache_reset(&t->dst_cache);
 386         dev_put_track(dev, &t->dev_tracker);
 387 }
 388
 389 /**
 390  * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
 391  *   @skb: received socket buffer
 392  *   @raw: the ICMPv6 error message data
 393  *
 394  * Return:
 395  *   0 if none was found,
 396  *   else index to encapsulation limit
 397  **/
 398
 399 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 400 {
 401         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 402         unsigned int nhoff = raw - skb->data;
 403         unsigned int off = nhoff + sizeof(*ipv6h);
 404         u8 next, nexthdr = ipv6h->nexthdr;
 405
 406         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 407                 struct ipv6_opt_hdr *hdr;
 408                 u16 optlen;
 409
 410                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 411                         break;
 412
 413                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 414                 if (nexthdr == NEXTHDR_FRAGMENT) {
 415                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 416                         if (frag_hdr->frag_off)
 417                                 break;
 418                         optlen = 8;
 419                 } else if (nexthdr == NEXTHDR_AUTH) {
 420                         optlen = ipv6_authlen(hdr);
 421                 } else {
 422                         optlen = ipv6_optlen(hdr);
 423                 }
 424                 /* cache hdr->nexthdr, since pskb_may_pull() might
 425                  * invalidate hdr
 426                  */
 427                 next = hdr->nexthdr;
 428                 if (nexthdr == NEXTHDR_DEST) {
 429                         u16 i = 2;
 430
 431                         /* Remember : hdr is no longer valid at this point. */
 432                         if (!pskb_may_pull(skb, off + optlen))
 433                                 break;
 434
 435                         while (1) {
 436                                 struct ipv6_tlv_tnl_enc_lim *tel;
 437
 438                                 /* No more room for encapsulation limit */
 439                                 if (i + sizeof(*tel) > optlen)
 440                                         break;
 441
 442                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 443                                 /* return index of option if found and valid */
 444                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 445                                     tel->length == 1)
 446                                         return i + off - nhoff;
 447                                 /* else jump to next option */
 448                                 if (tel->type)
 449                                         i += tel->length + 2;
 450                                 else
 451                                         i++;
 452                         }
 453                 }
 454                 nexthdr = next;
 455                 off += optlen;
 456         }
 457         return 0;
 458 }
 459 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 460
 461 /* ip6_tnl_err() should handle errors in the tunnel according to the
 462  * specifications in RFC 2473.
 463  */
 464 static int
 465 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 466             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 467 {
 468         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 469         struct net *net = dev_net(skb->dev);
 470         u8 rel_type = ICMPV6_DEST_UNREACH;
 471         u8 rel_code = ICMPV6_ADDR_UNREACH;
 472         __u32 rel_info = 0;
 473         struct ip6_tnl *t;
 474         int err = -ENOENT;
 475         int rel_msg = 0;
 476         u8 tproto;
 477         __u16 len;
 478
 479         /* If the packet doesn't contain the original IPv6 header we are
 480            in trouble since we might need the source address for further
 481            processing of the error. */
 482
 483         rcu_read_lock();
 484         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
 485         if (!t)
 486                 goto out;
 487
 488         tproto = READ_ONCE(t->parms.proto);
 489         if (tproto != ipproto && tproto != 0)
 490                 goto out;
 491
 492         err = 0;
 493
 494         switch (*type) {
 495         case ICMPV6_DEST_UNREACH:
 496                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 497                                     t->parms.name);
 498                 rel_msg = 1;
 499                 break;
 500         case ICMPV6_TIME_EXCEED:
 501                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 502                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 503                                             t->parms.name);
 504                         rel_msg = 1;
 505                 }
 506                 break;
 507         case ICMPV6_PARAMPROB: {
 508                 struct ipv6_tlv_tnl_enc_lim *tel;
 509                 __u32 teli;
 510
 511                 teli = 0;
 512                 if ((*code) == ICMPV6_HDR_FIELD)
 513                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 514
 515                 if (teli && teli == *info - 2) {
 516                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 517                         if (tel->encap_limit == 0) {
 518                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 519                                                     t->parms.name);
 520                                 rel_msg = 1;
 521                         }
 522                 } else {
 523                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 524                                             t->parms.name);
 525                 }
 526                 break;
 527         }
 528         case ICMPV6_PKT_TOOBIG: {
 529                 __u32 mtu;
 530
 531                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 532                                 sock_net_uid(net, NULL));
 533                 mtu = *info - offset;
 534                 if (mtu < IPV6_MIN_MTU)
 535                         mtu = IPV6_MIN_MTU;
 536                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 537                 if (len > mtu) {
 538                         rel_type = ICMPV6_PKT_TOOBIG;
 539                         rel_code = 0;
 540                         rel_info = mtu;
 541                         rel_msg = 1;
 542                 }
 543                 break;
 544         }
 545         case NDISC_REDIRECT:
 546                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 547                              sock_net_uid(net, NULL));
 548                 break;
 549         }
 550
 551         *type = rel_type;
 552         *code = rel_code;
 553         *info = rel_info;
 554         *msg = rel_msg;
 555
 556 out:
 557         rcu_read_unlock();
 558         return err;
 559 }
 560
 561 static int
 562 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 563            u8 type, u8 code, int offset, __be32 info)
 564 {
 565         __u32 rel_info = ntohl(info);
 566         const struct iphdr *eiph;
 567         struct sk_buff *skb2;
 568         int err, rel_msg = 0;
 569         u8 rel_type = type;
 570         u8 rel_code = code;
 571         struct rtable *rt;
 572         struct flowi4 fl4;
 573
 574         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 575                           &rel_msg, &rel_info, offset);
 576         if (err < 0)
 577                 return err;
 578
 579         if (rel_msg == 0)
 580                 return 0;
 581
 582         switch (rel_type) {
 583         case ICMPV6_DEST_UNREACH:
 584                 if (rel_code != ICMPV6_ADDR_UNREACH)
 585                         return 0;
 586                 rel_type = ICMP_DEST_UNREACH;
 587                 rel_code = ICMP_HOST_UNREACH;
 588                 break;
 589         case ICMPV6_PKT_TOOBIG:
 590                 if (rel_code != 0)
 591                         return 0;
 592                 rel_type = ICMP_DEST_UNREACH;
 593                 rel_code = ICMP_FRAG_NEEDED;
 594                 break;
 595         default:
 596                 return 0;
 597         }
 598
 599         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 600                 return 0;
 601
 602         skb2 = skb_clone(skb, GFP_ATOMIC);
 603         if (!skb2)
 604                 return 0;
 605
 606         skb_dst_drop(skb2);
 607
 608         skb_pull(skb2, offset);
 609         skb_reset_network_header(skb2);
 610         eiph = ip_hdr(skb2);
 611
 612         /* Try to guess incoming interface */
 613         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 614                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 615         if (IS_ERR(rt))
 616                 goto out;
 617
 618         skb2->dev = rt->dst.dev;
 619         ip_rt_put(rt);
 620
 621         /* route "incoming" packet */
 622         if (rt->rt_flags & RTCF_LOCAL) {
 623                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 624                                            eiph->daddr, eiph->saddr, 0, 0,
 625                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 626                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
 627                         if (!IS_ERR(rt))
 628                                 ip_rt_put(rt);
 629                         goto out;
 630                 }
 631                 skb_dst_set(skb2, &rt->dst);
 632         } else {
 633                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 634                                    skb2->dev) ||
 635                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
 636                         goto out;
 637         }
 638
 639         /* change mtu on this route */
 640         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 641                 if (rel_info > dst_mtu(skb_dst(skb2)))
 642                         goto out;
 643
 644                 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
 645         }
 646
 647         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 648
 649 out:
 650         kfree_skb(skb2);
 651         return 0;
 652 }
 653
 654 static int
 655 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 656            u8 type, u8 code, int offset, __be32 info)
 657 {
 658         __u32 rel_info = ntohl(info);
 659         int err, rel_msg = 0;
 660         u8 rel_type = type;
 661         u8 rel_code = code;
 662
 663         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 664                           &rel_msg, &rel_info, offset);
 665         if (err < 0)
 666                 return err;
 667
 668         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 669                 struct rt6_info *rt;
 670                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 671
 672                 if (!skb2)
 673                         return 0;
 674
 675                 skb_dst_drop(skb2);
 676                 skb_pull(skb2, offset);
 677                 skb_reset_network_header(skb2);
 678
 679                 /* Try to guess incoming interface */
 680                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 681                                 NULL, 0, skb2, 0);
 682
 683                 if (rt && rt->dst.dev)
 684                         skb2->dev = rt->dst.dev;
 685
 686                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 687
 688                 ip6_rt_put(rt);
 689
 690                 kfree_skb(skb2);
 691         }
 692
 693         return 0;
 694 }
 695
 696 static int
 697 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 698             u8 type, u8 code, int offset, __be32 info)
 699 {
 700         __u32 rel_info = ntohl(info);
 701         int err, rel_msg = 0;
 702         u8 rel_type = type;
 703         u8 rel_code = code;
 704
 705         err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
 706                           &rel_msg, &rel_info, offset);
 707         return err;
 708 }
 709
 710 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 711                                        const struct ipv6hdr *ipv6h,
 712                                        struct sk_buff *skb)
 713 {
 714         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 715
 716         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 717                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 718
 719         return IP6_ECN_decapsulate(ipv6h, skb);
 720 }
 721
 722 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 723                                        const struct ipv6hdr *ipv6h,
 724                                        struct sk_buff *skb)
 725 {
 726         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 727                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 728
 729         return IP6_ECN_decapsulate(ipv6h, skb);
 730 }
 731
 732 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 733                                                const struct ipv6hdr *ipv6h,
 734                                                struct sk_buff *skb)
 735 {
 736         /* ECN is not supported in AF_MPLS */
 737         return 0;
 738 }
 739
 740 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 741                              const struct in6_addr *laddr,
 742                              const struct in6_addr *raddr)
 743 {
 744         struct __ip6_tnl_parm *p = &t->parms;
 745         int ltype = ipv6_addr_type(laddr);
 746         int rtype = ipv6_addr_type(raddr);
 747         __u32 flags = 0;
 748
 749         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 750                 flags = IP6_TNL_F_CAP_PER_PACKET;
 751         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 752                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 753                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 754                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 755                 if (ltype&IPV6_ADDR_UNICAST)
 756                         flags |= IP6_TNL_F_CAP_XMIT;
 757                 if (rtype&IPV6_ADDR_UNICAST)
 758                         flags |= IP6_TNL_F_CAP_RCV;
 759         }
 760         return flags;
 761 }
 762 EXPORT_SYMBOL(ip6_tnl_get_cap);
 763
 764 /* called with rcu_read_lock() */
 765 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 766                                   const struct in6_addr *laddr,
 767                                   const struct in6_addr *raddr)
 768 {
 769         struct __ip6_tnl_parm *p = &t->parms;
 770         int ret = 0;
 771         struct net *net = t->net;
 772
 773         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 774             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 775              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 776                 struct net_device *ldev = NULL;
 777
 778                 if (p->link)
 779                         ldev = dev_get_by_index_rcu(net, p->link);
 780
 781                 if ((ipv6_addr_is_multicast(laddr) ||
 782                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 783                                                     0, IFA_F_TENTATIVE))) &&
 784                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 785                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 786                                                      0, IFA_F_TENTATIVE))))
 787                         ret = 1;
 788         }
 789         return ret;
 790 }
 791 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 792
 793 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 794                          const struct tnl_ptk_info *tpi,
 795                          struct metadata_dst *tun_dst,
 796                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 797                                                 const struct ipv6hdr *ipv6h,
 798                                                 struct sk_buff *skb),
 799                          bool log_ecn_err)
 800 {
 801         struct pcpu_sw_netstats *tstats;
 802         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 803         int err;
 804
 805         if ((!(tpi->flags & TUNNEL_CSUM) &&
 806              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 807             ((tpi->flags & TUNNEL_CSUM) &&
 808              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 809                 tunnel->dev->stats.rx_crc_errors++;
 810                 tunnel->dev->stats.rx_errors++;
 811                 goto drop;
 812         }
 813
 814         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 815                 if (!(tpi->flags & TUNNEL_SEQ) ||
 816                     (tunnel->i_seqno &&
 817                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 818                         tunnel->dev->stats.rx_fifo_errors++;
 819                         tunnel->dev->stats.rx_errors++;
 820                         goto drop;
 821                 }
 822                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 823         }
 824
 825         skb->protocol = tpi->proto;
 826
 827         /* Warning: All skb pointers will be invalidated! */
 828         if (tunnel->dev->type == ARPHRD_ETHER) {
 829                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 830                         tunnel->dev->stats.rx_length_errors++;
 831                         tunnel->dev->stats.rx_errors++;
 832                         goto drop;
 833                 }
 834
 835                 ipv6h = ipv6_hdr(skb);
 836                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 837                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 838         } else {
 839                 skb->dev = tunnel->dev;
 840                 skb_reset_mac_header(skb);
 841         }
 842
 843         skb_reset_network_header(skb);
 844         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 845
 846         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 847
 848         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 849         if (unlikely(err)) {
 850                 if (log_ecn_err)
 851                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 852                                              &ipv6h->saddr,
 853                                              ipv6_get_dsfield(ipv6h));
 854                 if (err > 1) {
 855                         ++tunnel->dev->stats.rx_frame_errors;
 856                         ++tunnel->dev->stats.rx_errors;
 857                         goto drop;
 858                 }
 859         }
 860
 861         tstats = this_cpu_ptr(tunnel->dev->tstats);
 862         u64_stats_update_begin(&tstats->syncp);
 863         tstats->rx_packets++;
 864         tstats->rx_bytes += skb->len;
 865         u64_stats_update_end(&tstats->syncp);
 866
 867         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 868
 869         if (tun_dst)
 870                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 871
 872         gro_cells_receive(&tunnel->gro_cells, skb);
 873         return 0;
 874
 875 drop:
 876         if (tun_dst)
 877                 dst_release((struct dst_entry *)tun_dst);
 878         kfree_skb(skb);
 879         return 0;
 880 }
 881
 882 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 883                 const struct tnl_ptk_info *tpi,
 884                 struct metadata_dst *tun_dst,
 885                 bool log_ecn_err)
 886 {
 887         int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 888                                     const struct ipv6hdr *ipv6h,
 889                                     struct sk_buff *skb);
 890
 891         dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
 892         if (tpi->proto == htons(ETH_P_IP))
 893                 dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
 894
 895         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 896                              log_ecn_err);
 897 }
 898 EXPORT_SYMBOL(ip6_tnl_rcv);
 899
 900 static const struct tnl_ptk_info tpi_v6 = {
 901         /* no tunnel info required for ipxip6. */
 902         .proto = htons(ETH_P_IPV6),
 903 };
 904
 905 static const struct tnl_ptk_info tpi_v4 = {
 906         /* no tunnel info required for ipxip6. */
 907         .proto = htons(ETH_P_IP),
 908 };
 909
 910 static const struct tnl_ptk_info tpi_mpls = {
 911         /* no tunnel info required for mplsip6. */
 912         .proto = htons(ETH_P_MPLS_UC),
 913 };
 914
 915 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 916                       const struct tnl_ptk_info *tpi,
 917                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 918                                                   const struct ipv6hdr *ipv6h,
 919                                                   struct sk_buff *skb))
 920 {
 921         struct ip6_tnl *t;
 922         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 923         struct metadata_dst *tun_dst = NULL;
 924         int ret = -1;
 925
 926         rcu_read_lock();
 927         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
 928
 929         if (t) {
 930                 u8 tproto = READ_ONCE(t->parms.proto);
 931
 932                 if (tproto != ipproto && tproto != 0)
 933                         goto drop;
 934                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 935                         goto drop;
 936                 ipv6h = ipv6_hdr(skb);
 937                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 938                         goto drop;
 939                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 940                         goto drop;
 941                 if (t->parms.collect_md) {
 942                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 943                         if (!tun_dst)
 944                                 goto drop;
 945                 }
 946                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 947                                     log_ecn_error);
 948         }
 949
 950         rcu_read_unlock();
 951
 952         return ret;
 953
 954 drop:
 955         rcu_read_unlock();
 956         kfree_skb(skb);
 957         return 0;
 958 }
 959
 960 static int ip4ip6_rcv(struct sk_buff *skb)
 961 {
 962         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 963                           ip4ip6_dscp_ecn_decapsulate);
 964 }
 965
 966 static int ip6ip6_rcv(struct sk_buff *skb)
 967 {
 968         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 969                           ip6ip6_dscp_ecn_decapsulate);
 970 }
 971
 972 static int mplsip6_rcv(struct sk_buff *skb)
 973 {
 974         return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
 975                           mplsip6_dscp_ecn_decapsulate);
 976 }
 977
 978 struct ipv6_tel_txoption {
 979         struct ipv6_txoptions ops;
 980         __u8 dst_opt[8];
 981 };
 982
 983 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 984 {
 985         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 986
 987         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 988         opt->dst_opt[3] = 1;
 989         opt->dst_opt[4] = encap_limit;
 990         opt->dst_opt[5] = IPV6_TLV_PADN;
 991         opt->dst_opt[6] = 1;
 992
 993         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 994         opt->ops.opt_nflen = 8;
 995 }
 996
 997 /**
 998  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 999  *   @t: the outgoing tunnel device
1000  *   @hdr: IPv6 header from the incoming packet
1001  *
1002  * Description:
1003  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1004  *   doesn't match source of incoming packet.
1005  *
1006  * Return:
1007  *   1 if conflict,
1008  *   0 else
1009  **/
1010
1011 static inline bool
1012 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1013 {
1014         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1015 }
1016
1017 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1018                      const struct in6_addr *laddr,
1019                      const struct in6_addr *raddr)
1020 {
1021         struct __ip6_tnl_parm *p = &t->parms;
1022         int ret = 0;
1023         struct net *net = t->net;
1024
1025         if (t->parms.collect_md)
1026                 return 1;
1027
1028         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1029             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1030              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1031                 struct net_device *ldev = NULL;
1032
1033                 rcu_read_lock();
1034                 if (p->link)
1035                         ldev = dev_get_by_index_rcu(net, p->link);
1036
1037                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1038                                                       0, IFA_F_TENTATIVE)))
1039                         pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1040                                             p->name);
1041                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1042                          !ipv6_addr_is_multicast(raddr) &&
1043                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1044                                                           true, 0, IFA_F_TENTATIVE)))
1045                         pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1046                                             p->name);
1047                 else
1048                         ret = 1;
1049                 rcu_read_unlock();
1050         }
1051         return ret;
1052 }
1053 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1054
1055 /**
1056  * ip6_tnl_xmit - encapsulate packet and send
1057  *   @skb: the outgoing socket buffer
1058  *   @dev: the outgoing tunnel device
1059  *   @dsfield: dscp code for outer header
1060  *   @fl6: flow of tunneled packet
1061  *   @encap_limit: encapsulation limit
1062  *   @pmtu: Path MTU is stored if packet is too big
1063  *   @proto: next header value
1064  *
1065  * Description:
1066  *   Build new header and do some sanity checks on the packet before sending
1067  *   it.
1068  *
1069  * Return:
1070  *   0 on success
1071  *   -1 fail
1072  *   %-EMSGSIZE message too big. return mtu in this case.
1073  **/
1074
1075 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1076                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1077                  __u8 proto)
1078 {
1079         struct ip6_tnl *t = netdev_priv(dev);
1080         struct net *net = t->net;
1081         struct net_device_stats *stats = &t->dev->stats;
1082         struct ipv6hdr *ipv6h;
1083         struct ipv6_tel_txoption opt;
1084         struct dst_entry *dst = NULL, *ndst = NULL;
1085         struct net_device *tdev;
1086         int mtu;
1087         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1088         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1089         unsigned int max_headroom = psh_hlen;
1090         bool use_cache = false;
1091         u8 hop_limit;
1092         int err = -1;
1093
1094         if (t->parms.collect_md) {
1095                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1096                 goto route_lookup;
1097         } else {
1098                 hop_limit = t->parms.hop_limit;
1099         }
1100
1101         /* NBMA tunnel */
1102         if (ipv6_addr_any(&t->parms.raddr)) {
1103                 if (skb->protocol == htons(ETH_P_IPV6)) {
1104                         struct in6_addr *addr6;
1105                         struct neighbour *neigh;
1106                         int addr_type;
1107
1108                         if (!skb_dst(skb))
1109                                 goto tx_err_link_failure;
1110
1111                         neigh = dst_neigh_lookup(skb_dst(skb),
1112                                                  &ipv6_hdr(skb)->daddr);
1113                         if (!neigh)
1114                                 goto tx_err_link_failure;
1115
1116                         addr6 = (struct in6_addr *)&neigh->primary_key;
1117                         addr_type = ipv6_addr_type(addr6);
1118
1119                         if (addr_type == IPV6_ADDR_ANY)
1120                                 addr6 = &ipv6_hdr(skb)->daddr;
1121
1122                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1123                         neigh_release(neigh);
1124                 } else if (skb->protocol == htons(ETH_P_IP)) {
1125                         const struct rtable *rt = skb_rtable(skb);
1126
1127                         if (!rt)
1128                                 goto tx_err_link_failure;
1129
1130                         if (rt->rt_gw_family == AF_INET6)
1131                                 memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1132                 }
1133         } else if (t->parms.proto != 0 && !(t->parms.flags &
1134                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1135                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1136                 /* enable the cache only if neither the outer protocol nor the
1137                  * routing decision depends on the current inner header value
1138                  */
1139                 use_cache = true;
1140         }
1141
1142         if (use_cache)
1143                 dst = dst_cache_get(&t->dst_cache);
1144
1145         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1146                 goto tx_err_link_failure;
1147
1148         if (!dst) {
1149 route_lookup:
1150                 /* add dsfield to flowlabel for route lookup */
1151                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1152
1153                 dst = ip6_route_output(net, NULL, fl6);
1154
1155                 if (dst->error)
1156                         goto tx_err_link_failure;
1157                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1158                 if (IS_ERR(dst)) {
1159                         err = PTR_ERR(dst);
1160                         dst = NULL;
1161                         goto tx_err_link_failure;
1162                 }
1163                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1164                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1165                                        &fl6->daddr, 0, &fl6->saddr))
1166                         goto tx_err_link_failure;
1167                 ndst = dst;
1168         }
1169
1170         tdev = dst->dev;
1171
1172         if (tdev == dev) {
1173                 stats->collisions++;
1174                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1175                                      t->parms.name);
1176                 goto tx_err_dst_release;
1177         }
1178         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1179         if (encap_limit >= 0) {
1180                 max_headroom += 8;
1181                 mtu -= 8;
1182         }
1183         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1184                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1185
1186         skb_dst_update_pmtu_no_confirm(skb, mtu);
1187         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1188                 *pmtu = mtu;
1189                 err = -EMSGSIZE;
1190                 goto tx_err_dst_release;
1191         }
1192
1193         if (t->err_count > 0) {
1194                 if (time_before(jiffies,
1195                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1196                         t->err_count--;
1197
1198                         dst_link_failure(skb);
1199                 } else {
1200                         t->err_count = 0;
1201                 }
1202         }
1203
1204         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1205
1206         /*
1207          * Okay, now see if we can stuff it in the buffer as-is.
1208          */
1209         max_headroom += LL_RESERVED_SPACE(tdev);
1210
1211         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1212             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1213                 struct sk_buff *new_skb;
1214
1215                 new_skb = skb_realloc_headroom(skb, max_headroom);
1216                 if (!new_skb)
1217                         goto tx_err_dst_release;
1218
1219                 if (skb->sk)
1220                         skb_set_owner_w(new_skb, skb->sk);
1221                 consume_skb(skb);
1222                 skb = new_skb;
1223         }
1224
1225         if (t->parms.collect_md) {
1226                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1227                         goto tx_err_dst_release;
1228         } else {
1229                 if (use_cache && ndst)
1230                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1231         }
1232         skb_dst_set(skb, dst);
1233
1234         if (hop_limit == 0) {
1235                 if (skb->protocol == htons(ETH_P_IP))
1236                         hop_limit = ip_hdr(skb)->ttl;
1237                 else if (skb->protocol == htons(ETH_P_IPV6))
1238                         hop_limit = ipv6_hdr(skb)->hop_limit;
1239                 else
1240                         hop_limit = ip6_dst_hoplimit(dst);
1241         }
1242
1243         /* Calculate max headroom for all the headers and adjust
1244          * needed_headroom if necessary.
1245          */
1246         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1247                         + dst->header_len + t->hlen;
1248         if (max_headroom > dev->needed_headroom)
1249                 dev->needed_headroom = max_headroom;
1250
1251         err = ip6_tnl_encap(skb, t, &proto, fl6);
1252         if (err)
1253                 return err;
1254
1255         if (encap_limit >= 0) {
1256                 init_tel_txopt(&opt, encap_limit);
1257                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1258         }
1259
1260         skb_push(skb, sizeof(struct ipv6hdr));
1261         skb_reset_network_header(skb);
1262         ipv6h = ipv6_hdr(skb);
1263         ip6_flow_hdr(ipv6h, dsfield,
1264                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1265         ipv6h->hop_limit = hop_limit;
1266         ipv6h->nexthdr = proto;
1267         ipv6h->saddr = fl6->saddr;
1268         ipv6h->daddr = fl6->daddr;
1269         ip6tunnel_xmit(NULL, skb, dev);
1270         return 0;
1271 tx_err_link_failure:
1272         stats->tx_carrier_errors++;
1273         dst_link_failure(skb);
1274 tx_err_dst_release:
1275         dst_release(dst);
1276         return err;
1277 }
1278 EXPORT_SYMBOL(ip6_tnl_xmit);
1279
1280 static inline int
1281 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1282                 u8 protocol)
1283 {
1284         struct ip6_tnl *t = netdev_priv(dev);
1285         struct ipv6hdr *ipv6h;
1286         const struct iphdr  *iph;
1287         int encap_limit = -1;
1288         __u16 offset;
1289         struct flowi6 fl6;
1290         __u8 dsfield, orig_dsfield;
1291         __u32 mtu;
1292         u8 tproto;
1293         int err;
1294
1295         tproto = READ_ONCE(t->parms.proto);
1296         if (tproto != protocol && tproto != 0)
1297                 return -1;
1298
1299         if (t->parms.collect_md) {
1300                 struct ip_tunnel_info *tun_info;
1301                 const struct ip_tunnel_key *key;
1302
1303                 tun_info = skb_tunnel_info(skb);
1304                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1305                              ip_tunnel_info_af(tun_info) != AF_INET6))
1306                         return -1;
1307                 key = &tun_info->key;
1308                 memset(&fl6, 0, sizeof(fl6));
1309                 fl6.flowi6_proto = protocol;
1310                 fl6.saddr = key->u.ipv6.src;
1311                 fl6.daddr = key->u.ipv6.dst;
1312                 fl6.flowlabel = key->label;
1313                 dsfield =  key->tos;
1314                 switch (protocol) {
1315                 case IPPROTO_IPIP:
1316                         iph = ip_hdr(skb);
1317                         orig_dsfield = ipv4_get_dsfield(iph);
1318                         break;
1319                 case IPPROTO_IPV6:
1320                         ipv6h = ipv6_hdr(skb);
1321                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1322                         break;
1323                 default:
1324                         orig_dsfield = dsfield;
1325                         break;
1326                 }
1327         } else {
1328                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1329                         encap_limit = t->parms.encap_limit;
1330                 if (protocol == IPPROTO_IPV6) {
1331                         offset = ip6_tnl_parse_tlv_enc_lim(skb,
1332                                                 skb_network_header(skb));
1333                         /* ip6_tnl_parse_tlv_enc_lim() might have
1334                          * reallocated skb->head
1335                          */
1336                         if (offset > 0) {
1337                                 struct ipv6_tlv_tnl_enc_lim *tel;
1338
1339                                 tel = (void *)&skb_network_header(skb)[offset];
1340                                 if (tel->encap_limit == 0) {
1341                                         icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1342                                                         ICMPV6_HDR_FIELD, offset + 2);
1343                                         return -1;
1344                                 }
1345                                 encap_limit = tel->encap_limit - 1;
1346                         }
1347                 }
1348
1349                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1350                 fl6.flowi6_proto = protocol;
1351
1352                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1353                         fl6.flowi6_mark = skb->mark;
1354                 else
1355                         fl6.flowi6_mark = t->parms.fwmark;
1356                 switch (protocol) {
1357                 case IPPROTO_IPIP:
1358                         iph = ip_hdr(skb);
1359                         orig_dsfield = ipv4_get_dsfield(iph);
1360                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1361                                 dsfield = orig_dsfield;
1362                         else
1363                                 dsfield = ip6_tclass(t->parms.flowinfo);
1364                         break;
1365                 case IPPROTO_IPV6:
1366                         ipv6h = ipv6_hdr(skb);
1367                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1368                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1369                                 dsfield = orig_dsfield;
1370                         else
1371                                 dsfield = ip6_tclass(t->parms.flowinfo);
1372                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1373                                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1374                         break;
1375                 default:
1376                         orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1377                         break;
1378                 }
1379         }
1380
1381         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1382         dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1383
1384         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1385                 return -1;
1386
1387         skb_set_inner_ipproto(skb, protocol);
1388
1389         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1390                            protocol);
1391         if (err != 0) {
1392                 /* XXX: send ICMP error even if DF is not set. */
1393                 if (err == -EMSGSIZE)
1394                         switch (protocol) {
1395                         case IPPROTO_IPIP:
1396                                 icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1397                                               ICMP_FRAG_NEEDED, htonl(mtu));
1398                                 break;
1399                         case IPPROTO_IPV6:
1400                                 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1401                                 break;
1402                         default:
1403                                 break;
1404                         }
1405                 return -1;
1406         }
1407
1408         return 0;
1409 }
1410
1411 static netdev_tx_t
1412 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1413 {
1414         struct ip6_tnl *t = netdev_priv(dev);
1415         struct net_device_stats *stats = &t->dev->stats;
1416         u8 ipproto;
1417         int ret;
1418
1419         if (!pskb_inet_may_pull(skb))
1420                 goto tx_err;
1421
1422         switch (skb->protocol) {
1423         case htons(ETH_P_IP):
1424                 ipproto = IPPROTO_IPIP;
1425                 break;
1426         case htons(ETH_P_IPV6):
1427                 if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1428                         goto tx_err;
1429                 ipproto = IPPROTO_IPV6;
1430                 break;
1431         case htons(ETH_P_MPLS_UC):
1432                 ipproto = IPPROTO_MPLS;
1433                 break;
1434         default:
1435                 goto tx_err;
1436         }
1437
1438         ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1439         if (ret < 0)
1440                 goto tx_err;
1441
1442         return NETDEV_TX_OK;
1443
1444 tx_err:
1445         stats->tx_errors++;
1446         stats->tx_dropped++;
1447         kfree_skb(skb);
1448         return NETDEV_TX_OK;
1449 }
1450
1451 static void ip6_tnl_link_config(struct ip6_tnl *t)
1452 {
1453         struct net_device *dev = t->dev;
1454         struct net_device *tdev = NULL;
1455         struct __ip6_tnl_parm *p = &t->parms;
1456         struct flowi6 *fl6 = &t->fl.u.ip6;
1457         unsigned int mtu;
1458         int t_hlen;
1459
1460         __dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1461         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1462
1463         /* Set up flowi template */
1464         fl6->saddr = p->laddr;
1465         fl6->daddr = p->raddr;
1466         fl6->flowi6_oif = p->link;
1467         fl6->flowlabel = 0;
1468
1469         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1470                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1471         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1472                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1473
1474         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1475         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1476
1477         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1478                 dev->flags |= IFF_POINTOPOINT;
1479         else
1480                 dev->flags &= ~IFF_POINTOPOINT;
1481
1482         t->tun_hlen = 0;
1483         t->hlen = t->encap_hlen + t->tun_hlen;
1484         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1485
1486         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1487                 int strict = (ipv6_addr_type(&p->raddr) &
1488                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1489
1490                 struct rt6_info *rt = rt6_lookup(t->net,
1491                                                  &p->raddr, &p->laddr,
1492                                                  p->link, NULL, strict);
1493                 if (rt) {
1494                         tdev = rt->dst.dev;
1495                         ip6_rt_put(rt);
1496                 }
1497
1498                 if (!tdev && p->link)
1499                         tdev = __dev_get_by_index(t->net, p->link);
1500
1501                 if (tdev) {
1502                         dev->hard_header_len = tdev->hard_header_len + t_hlen;
1503                         mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1504
1505                         dev->mtu = mtu - t_hlen;
1506                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1507                                 dev->mtu -= 8;
1508
1509                         if (dev->mtu < IPV6_MIN_MTU)
1510                                 dev->mtu = IPV6_MIN_MTU;
1511                 }
1512         }
1513 }
1514
1515 /**
1516  * ip6_tnl_change - update the tunnel parameters
1517  *   @t: tunnel to be changed
1518  *   @p: tunnel configuration parameters
1519  *
1520  * Description:
1521  *   ip6_tnl_change() updates the tunnel parameters
1522  **/
1523
1524 static int
1525 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1526 {
1527         t->parms.laddr = p->laddr;
1528         t->parms.raddr = p->raddr;
1529         t->parms.flags = p->flags;
1530         t->parms.hop_limit = p->hop_limit;
1531         t->parms.encap_limit = p->encap_limit;
1532         t->parms.flowinfo = p->flowinfo;
1533         t->parms.link = p->link;
1534         t->parms.proto = p->proto;
1535         t->parms.fwmark = p->fwmark;
1536         dst_cache_reset(&t->dst_cache);
1537         ip6_tnl_link_config(t);
1538         return 0;
1539 }
1540
1541 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1542 {
1543         struct net *net = t->net;
1544         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1545         int err;
1546
1547         ip6_tnl_unlink(ip6n, t);
1548         synchronize_net();
1549         err = ip6_tnl_change(t, p);
1550         ip6_tnl_link(ip6n, t);
1551         netdev_state_change(t->dev);
1552         return err;
1553 }
1554
1555 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1556 {
1557         /* for default tnl0 device allow to change only the proto */
1558         t->parms.proto = p->proto;
1559         netdev_state_change(t->dev);
1560         return 0;
1561 }
1562
1563 static void
1564 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1565 {
1566         p->laddr = u->laddr;
1567         p->raddr = u->raddr;
1568         p->flags = u->flags;
1569         p->hop_limit = u->hop_limit;
1570         p->encap_limit = u->encap_limit;
1571         p->flowinfo = u->flowinfo;
1572         p->link = u->link;
1573         p->proto = u->proto;
1574         memcpy(p->name, u->name, sizeof(u->name));
1575 }
1576
1577 static void
1578 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1579 {
1580         u->laddr = p->laddr;
1581         u->raddr = p->raddr;
1582         u->flags = p->flags;
1583         u->hop_limit = p->hop_limit;
1584         u->encap_limit = p->encap_limit;
1585         u->flowinfo = p->flowinfo;
1586         u->link = p->link;
1587         u->proto = p->proto;
1588         memcpy(u->name, p->name, sizeof(u->name));
1589 }
1590
1591 /**
1592  * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1593  *   @dev: virtual device associated with tunnel
1594  *   @ifr: unused
1595  *   @data: parameters passed from userspace
1596  *   @cmd: command to be performed
1597  *
1598  * Description:
1599  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1600  *   from userspace.
1601  *
1602  *   The possible commands are the following:
1603  *     %SIOCGETTUNNEL: get tunnel parameters for device
1604  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1605  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1606  *     %SIOCDELTUNNEL: delete tunnel
1607  *
1608  *   The fallback device "ip6tnl0", created during module
1609  *   initialization, can be used for creating other tunnel devices.
1610  *
1611  * Return:
1612  *   0 on success,
1613  *   %-EFAULT if unable to copy data to or from userspace,
1614  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1615  *   %-EINVAL if passed tunnel parameters are invalid,
1616  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1617  *   %-ENODEV if attempting to change or delete a nonexisting device
1618  **/
1619
1620 static int
1621 ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1622                        void __user *data, int cmd)
1623 {
1624         int err = 0;
1625         struct ip6_tnl_parm p;
1626         struct __ip6_tnl_parm p1;
1627         struct ip6_tnl *t = netdev_priv(dev);
1628         struct net *net = t->net;
1629         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1630
1631         memset(&p1, 0, sizeof(p1));
1632
1633         switch (cmd) {
1634         case SIOCGETTUNNEL:
1635                 if (dev == ip6n->fb_tnl_dev) {
1636                         if (copy_from_user(&p, data, sizeof(p))) {
1637                                 err = -EFAULT;
1638                                 break;
1639                         }
1640                         ip6_tnl_parm_from_user(&p1, &p);
1641                         t = ip6_tnl_locate(net, &p1, 0);
1642                         if (IS_ERR(t))
1643                                 t = netdev_priv(dev);
1644                 } else {
1645                         memset(&p, 0, sizeof(p));
1646                 }
1647                 ip6_tnl_parm_to_user(&p, &t->parms);
1648                 if (copy_to_user(data, &p, sizeof(p)))
1649                         err = -EFAULT;
1650                 break;
1651         case SIOCADDTUNNEL:
1652         case SIOCCHGTUNNEL:
1653                 err = -EPERM;
1654                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1655                         break;
1656                 err = -EFAULT;
1657                 if (copy_from_user(&p, data, sizeof(p)))
1658                         break;
1659                 err = -EINVAL;
1660                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1661                     p.proto != 0)
1662                         break;
1663                 ip6_tnl_parm_from_user(&p1, &p);
1664                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1665                 if (cmd == SIOCCHGTUNNEL) {
1666                         if (!IS_ERR(t)) {
1667                                 if (t->dev != dev) {
1668                                         err = -EEXIST;
1669                                         break;
1670                                 }
1671                         } else
1672                                 t = netdev_priv(dev);
1673                         if (dev == ip6n->fb_tnl_dev)
1674                                 err = ip6_tnl0_update(t, &p1);
1675                         else
1676                                 err = ip6_tnl_update(t, &p1);
1677                 }
1678                 if (!IS_ERR(t)) {
1679                         err = 0;
1680                         ip6_tnl_parm_to_user(&p, &t->parms);
1681                         if (copy_to_user(data, &p, sizeof(p)))
1682                                 err = -EFAULT;
1683
1684                 } else {
1685                         err = PTR_ERR(t);
1686                 }
1687                 break;
1688         case SIOCDELTUNNEL:
1689                 err = -EPERM;
1690                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1691                         break;
1692
1693                 if (dev == ip6n->fb_tnl_dev) {
1694                         err = -EFAULT;
1695                         if (copy_from_user(&p, data, sizeof(p)))
1696                                 break;
1697                         err = -ENOENT;
1698                         ip6_tnl_parm_from_user(&p1, &p);
1699                         t = ip6_tnl_locate(net, &p1, 0);
1700                         if (IS_ERR(t))
1701                                 break;
1702                         err = -EPERM;
1703                         if (t->dev == ip6n->fb_tnl_dev)
1704                                 break;
1705                         dev = t->dev;
1706                 }
1707                 err = 0;
1708                 unregister_netdevice(dev);
1709                 break;
1710         default:
1711                 err = -EINVAL;
1712         }
1713         return err;
1714 }
1715
1716 /**
1717  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1718  *   @dev: virtual device associated with tunnel
1719  *   @new_mtu: the new mtu
1720  *
1721  * Return:
1722  *   0 on success,
1723  *   %-EINVAL if mtu too small
1724  **/
1725
1726 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1727 {
1728         struct ip6_tnl *tnl = netdev_priv(dev);
1729
1730         if (tnl->parms.proto == IPPROTO_IPV6) {
1731                 if (new_mtu < IPV6_MIN_MTU)
1732                         return -EINVAL;
1733         } else {
1734                 if (new_mtu < ETH_MIN_MTU)
1735                         return -EINVAL;
1736         }
1737         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1738                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1739                         return -EINVAL;
1740         } else {
1741                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1742                         return -EINVAL;
1743         }
1744         dev->mtu = new_mtu;
1745         return 0;
1746 }
1747 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1748
1749 int ip6_tnl_get_iflink(const struct net_device *dev)
1750 {
1751         struct ip6_tnl *t = netdev_priv(dev);
1752
1753         return t->parms.link;
1754 }
1755 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1756
1757 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1758                           unsigned int num)
1759 {
1760         if (num >= MAX_IPTUN_ENCAP_OPS)
1761                 return -ERANGE;
1762
1763         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1764                         &ip6tun_encaps[num],
1765                         NULL, ops) ? 0 : -1;
1766 }
1767 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1768
1769 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1770                           unsigned int num)
1771 {
1772         int ret;
1773
1774         if (num >= MAX_IPTUN_ENCAP_OPS)
1775                 return -ERANGE;
1776
1777         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1778                        &ip6tun_encaps[num],
1779                        ops, NULL) == ops) ? 0 : -1;
1780
1781         synchronize_net();
1782
1783         return ret;
1784 }
1785 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1786
1787 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1788                         struct ip_tunnel_encap *ipencap)
1789 {
1790         int hlen;
1791
1792         memset(&t->encap, 0, sizeof(t->encap));
1793
1794         hlen = ip6_encap_hlen(ipencap);
1795         if (hlen < 0)
1796                 return hlen;
1797
1798         t->encap.type = ipencap->type;
1799         t->encap.sport = ipencap->sport;
1800         t->encap.dport = ipencap->dport;
1801         t->encap.flags = ipencap->flags;
1802
1803         t->encap_hlen = hlen;
1804         t->hlen = t->encap_hlen + t->tun_hlen;
1805
1806         return 0;
1807 }
1808 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1809
1810 static const struct net_device_ops ip6_tnl_netdev_ops = {
1811         .ndo_init       = ip6_tnl_dev_init,
1812         .ndo_uninit     = ip6_tnl_dev_uninit,
1813         .ndo_start_xmit = ip6_tnl_start_xmit,
1814         .ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1815         .ndo_change_mtu = ip6_tnl_change_mtu,
1816         .ndo_get_stats64 = dev_get_tstats64,
1817         .ndo_get_iflink = ip6_tnl_get_iflink,
1818 };
1819
1820 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1821                          NETIF_F_FRAGLIST |     \
1822                          NETIF_F_HIGHDMA |      \
1823                          NETIF_F_GSO_SOFTWARE | \
1824                          NETIF_F_HW_CSUM)
1825
1826 /**
1827  * ip6_tnl_dev_setup - setup virtual tunnel device
1828  *   @dev: virtual device associated with tunnel
1829  *
1830  * Description:
1831  *   Initialize function pointers and device parameters
1832  **/
1833
1834 static void ip6_tnl_dev_setup(struct net_device *dev)
1835 {
1836         dev->netdev_ops = &ip6_tnl_netdev_ops;
1837         dev->header_ops = &ip_tunnel_header_ops;
1838         dev->needs_free_netdev = true;
1839         dev->priv_destructor = ip6_dev_free;
1840
1841         dev->type = ARPHRD_TUNNEL6;
1842         dev->flags |= IFF_NOARP;
1843         dev->addr_len = sizeof(struct in6_addr);
1844         dev->features |= NETIF_F_LLTX;
1845         netif_keep_dst(dev);
1846
1847         dev->features           |= IPXIPX_FEATURES;
1848         dev->hw_features        |= IPXIPX_FEATURES;
1849
1850         /* This perm addr will be used as interface identifier by IPv6 */
1851         dev->addr_assign_type = NET_ADDR_RANDOM;
1852         eth_random_addr(dev->perm_addr);
1853 }
1854
1855
1856 /**
1857  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1858  *   @dev: virtual device associated with tunnel
1859  **/
1860
1861 static inline int
1862 ip6_tnl_dev_init_gen(struct net_device *dev)
1863 {
1864         struct ip6_tnl *t = netdev_priv(dev);
1865         int ret;
1866         int t_hlen;
1867
1868         t->dev = dev;
1869         t->net = dev_net(dev);
1870         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1871         if (!dev->tstats)
1872                 return -ENOMEM;
1873
1874         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1875         if (ret)
1876                 goto free_stats;
1877
1878         ret = gro_cells_init(&t->gro_cells, dev);
1879         if (ret)
1880                 goto destroy_dst;
1881
1882         t->tun_hlen = 0;
1883         t->hlen = t->encap_hlen + t->tun_hlen;
1884         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1885
1886         dev->type = ARPHRD_TUNNEL6;
1887         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1888         dev->mtu = ETH_DATA_LEN - t_hlen;
1889         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1890                 dev->mtu -= 8;
1891         dev->min_mtu = ETH_MIN_MTU;
1892         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1893
1894         dev_hold_track(dev, &t->dev_tracker, GFP_KERNEL);
1895         return 0;
1896
1897 destroy_dst:
1898         dst_cache_destroy(&t->dst_cache);
1899 free_stats:
1900         free_percpu(dev->tstats);
1901         dev->tstats = NULL;
1902
1903         return ret;
1904 }
1905
1906 /**
1907  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1908  *   @dev: virtual device associated with tunnel
1909  **/
1910
1911 static int ip6_tnl_dev_init(struct net_device *dev)
1912 {
1913         struct ip6_tnl *t = netdev_priv(dev);
1914         int err = ip6_tnl_dev_init_gen(dev);
1915
1916         if (err)
1917                 return err;
1918         ip6_tnl_link_config(t);
1919         if (t->parms.collect_md)
1920                 netif_keep_dst(dev);
1921         return 0;
1922 }
1923
1924 /**
1925  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1926  *   @dev: fallback device
1927  *
1928  * Return: 0
1929  **/
1930
1931 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1932 {
1933         struct ip6_tnl *t = netdev_priv(dev);
1934         struct net *net = dev_net(dev);
1935         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1936
1937         t->parms.proto = IPPROTO_IPV6;
1938
1939         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1940         return 0;
1941 }
1942
1943 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1944                             struct netlink_ext_ack *extack)
1945 {
1946         u8 proto;
1947
1948         if (!data || !data[IFLA_IPTUN_PROTO])
1949                 return 0;
1950
1951         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1952         if (proto != IPPROTO_IPV6 &&
1953             proto != IPPROTO_IPIP &&
1954             proto != 0)
1955                 return -EINVAL;
1956
1957         return 0;
1958 }
1959
1960 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1961                                   struct __ip6_tnl_parm *parms)
1962 {
1963         memset(parms, 0, sizeof(*parms));
1964
1965         if (!data)
1966                 return;
1967
1968         if (data[IFLA_IPTUN_LINK])
1969                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1970
1971         if (data[IFLA_IPTUN_LOCAL])
1972                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1973
1974         if (data[IFLA_IPTUN_REMOTE])
1975                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1976
1977         if (data[IFLA_IPTUN_TTL])
1978                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1979
1980         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1981                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1982
1983         if (data[IFLA_IPTUN_FLOWINFO])
1984                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1985
1986         if (data[IFLA_IPTUN_FLAGS])
1987                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1988
1989         if (data[IFLA_IPTUN_PROTO])
1990                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1991
1992         if (data[IFLA_IPTUN_COLLECT_METADATA])
1993                 parms->collect_md = true;
1994
1995         if (data[IFLA_IPTUN_FWMARK])
1996                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1997 }
1998
1999 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
2000                                         struct ip_tunnel_encap *ipencap)
2001 {
2002         bool ret = false;
2003
2004         memset(ipencap, 0, sizeof(*ipencap));
2005
2006         if (!data)
2007                 return ret;
2008
2009         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2010                 ret = true;
2011                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2012         }
2013
2014         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2015                 ret = true;
2016                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2017         }
2018
2019         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2020                 ret = true;
2021                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2022         }
2023
2024         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2025                 ret = true;
2026                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2027         }
2028
2029         return ret;
2030 }
2031
2032 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2033                            struct nlattr *tb[], struct nlattr *data[],
2034                            struct netlink_ext_ack *extack)
2035 {
2036         struct net *net = dev_net(dev);
2037         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2038         struct ip_tunnel_encap ipencap;
2039         struct ip6_tnl *nt, *t;
2040         int err;
2041
2042         nt = netdev_priv(dev);
2043
2044         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2045                 err = ip6_tnl_encap_setup(nt, &ipencap);
2046                 if (err < 0)
2047                         return err;
2048         }
2049
2050         ip6_tnl_netlink_parms(data, &nt->parms);
2051
2052         if (nt->parms.collect_md) {
2053                 if (rtnl_dereference(ip6n->collect_md_tun))
2054                         return -EEXIST;
2055         } else {
2056                 t = ip6_tnl_locate(net, &nt->parms, 0);
2057                 if (!IS_ERR(t))
2058                         return -EEXIST;
2059         }
2060
2061         err = ip6_tnl_create2(dev);
2062         if (!err && tb[IFLA_MTU])
2063                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2064
2065         return err;
2066 }
2067
2068 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2069                               struct nlattr *data[],
2070                               struct netlink_ext_ack *extack)
2071 {
2072         struct ip6_tnl *t = netdev_priv(dev);
2073         struct __ip6_tnl_parm p;
2074         struct net *net = t->net;
2075         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2076         struct ip_tunnel_encap ipencap;
2077
2078         if (dev == ip6n->fb_tnl_dev)
2079                 return -EINVAL;
2080
2081         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2082                 int err = ip6_tnl_encap_setup(t, &ipencap);
2083
2084                 if (err < 0)
2085                         return err;
2086         }
2087         ip6_tnl_netlink_parms(data, &p);
2088         if (p.collect_md)
2089                 return -EINVAL;
2090
2091         t = ip6_tnl_locate(net, &p, 0);
2092         if (!IS_ERR(t)) {
2093                 if (t->dev != dev)
2094                         return -EEXIST;
2095         } else
2096                 t = netdev_priv(dev);
2097
2098         return ip6_tnl_update(t, &p);
2099 }
2100
2101 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2102 {
2103         struct net *net = dev_net(dev);
2104         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2105
2106         if (dev != ip6n->fb_tnl_dev)
2107                 unregister_netdevice_queue(dev, head);
2108 }
2109
2110 static size_t ip6_tnl_get_size(const struct net_device *dev)
2111 {
2112         return
2113                 /* IFLA_IPTUN_LINK */
2114                 nla_total_size(4) +
2115                 /* IFLA_IPTUN_LOCAL */
2116                 nla_total_size(sizeof(struct in6_addr)) +
2117                 /* IFLA_IPTUN_REMOTE */
2118                 nla_total_size(sizeof(struct in6_addr)) +
2119                 /* IFLA_IPTUN_TTL */
2120                 nla_total_size(1) +
2121                 /* IFLA_IPTUN_ENCAP_LIMIT */
2122                 nla_total_size(1) +
2123                 /* IFLA_IPTUN_FLOWINFO */
2124                 nla_total_size(4) +
2125                 /* IFLA_IPTUN_FLAGS */
2126                 nla_total_size(4) +
2127                 /* IFLA_IPTUN_PROTO */
2128                 nla_total_size(1) +
2129                 /* IFLA_IPTUN_ENCAP_TYPE */
2130                 nla_total_size(2) +
2131                 /* IFLA_IPTUN_ENCAP_FLAGS */
2132                 nla_total_size(2) +
2133                 /* IFLA_IPTUN_ENCAP_SPORT */
2134                 nla_total_size(2) +
2135                 /* IFLA_IPTUN_ENCAP_DPORT */
2136                 nla_total_size(2) +
2137                 /* IFLA_IPTUN_COLLECT_METADATA */
2138                 nla_total_size(0) +
2139                 /* IFLA_IPTUN_FWMARK */
2140                 nla_total_size(4) +
2141                 0;
2142 }
2143
2144 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2145 {
2146         struct ip6_tnl *tunnel = netdev_priv(dev);
2147         struct __ip6_tnl_parm *parm = &tunnel->parms;
2148
2149         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2150             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2151             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2152             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2153             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2154             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2155             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2156             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2157             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2158                 goto nla_put_failure;
2159
2160         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2161             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2162             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2163             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2164                 goto nla_put_failure;
2165
2166         if (parm->collect_md)
2167                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2168                         goto nla_put_failure;
2169
2170         return 0;
2171
2172 nla_put_failure:
2173         return -EMSGSIZE;
2174 }
2175
2176 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2177 {
2178         struct ip6_tnl *tunnel = netdev_priv(dev);
2179
2180         return tunnel->net;
2181 }
2182 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2183
2184 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2185         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2186         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2187         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2188         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2189         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2190         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2191         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2192         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2193         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2194         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2195         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2196         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2197         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2198         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2199 };
2200
2201 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2202         .kind           = "ip6tnl",
2203         .maxtype        = IFLA_IPTUN_MAX,
2204         .policy         = ip6_tnl_policy,
2205         .priv_size      = sizeof(struct ip6_tnl),
2206         .setup          = ip6_tnl_dev_setup,
2207         .validate       = ip6_tnl_validate,
2208         .newlink        = ip6_tnl_newlink,
2209         .changelink     = ip6_tnl_changelink,
2210         .dellink        = ip6_tnl_dellink,
2211         .get_size       = ip6_tnl_get_size,
2212         .fill_info      = ip6_tnl_fill_info,
2213         .get_link_net   = ip6_tnl_get_link_net,
2214 };
2215
2216 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2217         .handler        = ip4ip6_rcv,
2218         .err_handler    = ip4ip6_err,
2219         .priority       =       1,
2220 };
2221
2222 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2223         .handler        = ip6ip6_rcv,
2224         .err_handler    = ip6ip6_err,
2225         .priority       =       1,
2226 };
2227
2228 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2229         .handler        = mplsip6_rcv,
2230         .err_handler    = mplsip6_err,
2231         .priority       =       1,
2232 };
2233
2234 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2235 {
2236         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2237         struct net_device *dev, *aux;
2238         int h;
2239         struct ip6_tnl *t;
2240
2241         for_each_netdev_safe(net, dev, aux)
2242                 if (dev->rtnl_link_ops == &ip6_link_ops)
2243                         unregister_netdevice_queue(dev, list);
2244
2245         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2246                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2247                 while (t) {
2248                         /* If dev is in the same netns, it has already
2249                          * been added to the list by the previous loop.
2250                          */
2251                         if (!net_eq(dev_net(t->dev), net))
2252                                 unregister_netdevice_queue(t->dev, list);
2253                         t = rtnl_dereference(t->next);
2254                 }
2255         }
2256
2257         t = rtnl_dereference(ip6n->tnls_wc[0]);
2258         while (t) {
2259                 /* If dev is in the same netns, it has already
2260                  * been added to the list by the previous loop.
2261                  */
2262                 if (!net_eq(dev_net(t->dev), net))
2263                         unregister_netdevice_queue(t->dev, list);
2264                 t = rtnl_dereference(t->next);
2265         }
2266 }
2267
2268 static int __net_init ip6_tnl_init_net(struct net *net)
2269 {
2270         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2271         struct ip6_tnl *t = NULL;
2272         int err;
2273
2274         ip6n->tnls[0] = ip6n->tnls_wc;
2275         ip6n->tnls[1] = ip6n->tnls_r_l;
2276
2277         if (!net_has_fallback_tunnels(net))
2278                 return 0;
2279         err = -ENOMEM;
2280         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2281                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2282
2283         if (!ip6n->fb_tnl_dev)
2284                 goto err_alloc_dev;
2285         dev_net_set(ip6n->fb_tnl_dev, net);
2286         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2287         /* FB netdevice is special: we have one, and only one per netns.
2288          * Allowing to move it to another netns is clearly unsafe.
2289          */
2290         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2291
2292         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2293         if (err < 0)
2294                 goto err_register;
2295
2296         err = register_netdev(ip6n->fb_tnl_dev);
2297         if (err < 0)
2298                 goto err_register;
2299
2300         t = netdev_priv(ip6n->fb_tnl_dev);
2301
2302         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2303         return 0;
2304
2305 err_register:
2306         free_netdev(ip6n->fb_tnl_dev);
2307 err_alloc_dev:
2308         return err;
2309 }
2310
2311 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2312 {
2313         struct net *net;
2314         LIST_HEAD(list);
2315
2316         rtnl_lock();
2317         list_for_each_entry(net, net_list, exit_list)
2318                 ip6_tnl_destroy_tunnels(net, &list);
2319         unregister_netdevice_many(&list);
2320         rtnl_unlock();
2321 }
2322
2323 static struct pernet_operations ip6_tnl_net_ops = {
2324         .init = ip6_tnl_init_net,
2325         .exit_batch = ip6_tnl_exit_batch_net,
2326         .id   = &ip6_tnl_net_id,
2327         .size = sizeof(struct ip6_tnl_net),
2328 };
2329
2330 /**
2331  * ip6_tunnel_init - register protocol and reserve needed resources
2332  *
2333  * Return: 0 on success
2334  **/
2335
2336 static int __init ip6_tunnel_init(void)
2337 {
2338         int  err;
2339
2340         if (!ipv6_mod_enabled())
2341                 return -EOPNOTSUPP;
2342
2343         err = register_pernet_device(&ip6_tnl_net_ops);
2344         if (err < 0)
2345                 goto out_pernet;
2346
2347         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2348         if (err < 0) {
2349                 pr_err("%s: can't register ip4ip6\n", __func__);
2350                 goto out_ip4ip6;
2351         }
2352
2353         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2354         if (err < 0) {
2355                 pr_err("%s: can't register ip6ip6\n", __func__);
2356                 goto out_ip6ip6;
2357         }
2358
2359         if (ip6_tnl_mpls_supported()) {
2360                 err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2361                 if (err < 0) {
2362                         pr_err("%s: can't register mplsip6\n", __func__);
2363                         goto out_mplsip6;
2364                 }
2365         }
2366
2367         err = rtnl_link_register(&ip6_link_ops);
2368         if (err < 0)
2369                 goto rtnl_link_failed;
2370
2371         return 0;
2372
2373 rtnl_link_failed:
2374         if (ip6_tnl_mpls_supported())
2375                 xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2376 out_mplsip6:
2377         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2378 out_ip6ip6:
2379         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2380 out_ip4ip6:
2381         unregister_pernet_device(&ip6_tnl_net_ops);
2382 out_pernet:
2383         return err;
2384 }
2385
2386 /**
2387  * ip6_tunnel_cleanup - free resources and unregister protocol
2388  **/
2389
2390 static void __exit ip6_tunnel_cleanup(void)
2391 {
2392         rtnl_link_unregister(&ip6_link_ops);
2393         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2394                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2395
2396         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2397                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2398
2399         if (ip6_tnl_mpls_supported() &&
2400             xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2401                 pr_info("%s: can't deregister mplsip6\n", __func__);
2402         unregister_pernet_device(&ip6_tnl_net_ops);
2403 }
2404
2405 module_init(ip6_tunnel_init);
2406 module_exit(ip6_tunnel_cleanup);