net/ipv6/ip6_tunnel.c

   1 /*
   2  *      IPv6 tunneling device
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   7  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   8  *
   9  *      Based on:
  10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  11  *
  12  *      RFC 2473
  13  *
  14  *      This program is free software; you can redistribute it and/or
  15  *      modify it under the terms of the GNU General Public License
  16  *      as published by the Free Software Foundation; either version
  17  *      2 of the License, or (at your option) any later version.
  18  *
  19  */
  20
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/module.h>
  24 #include <linux/capability.h>
  25 #include <linux/errno.h>
  26 #include <linux/types.h>
  27 #include <linux/sockios.h>
  28 #include <linux/icmp.h>
  29 #include <linux/if.h>
  30 #include <linux/in.h>
  31 #include <linux/ip.h>
  32 #include <linux/net.h>
  33 #include <linux/in6.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/if_arp.h>
  36 #include <linux/icmpv6.h>
  37 #include <linux/init.h>
  38 #include <linux/route.h>
  39 #include <linux/rtnetlink.h>
  40 #include <linux/netfilter_ipv6.h>
  41 #include <linux/slab.h>
  42 #include <linux/hash.h>
  43 #include <linux/etherdevice.h>
  44
  45 #include <asm/uaccess.h>
  46 #include <linux/atomic.h>
  47
  48 #include <net/icmp.h>
  49 #include <net/ip.h>
  50 #include <net/ip_tunnels.h>
  51 #include <net/ipv6.h>
  52 #include <net/ip6_route.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_tunnel.h>
  55 #include <net/xfrm.h>
  56 #include <net/dsfield.h>
  57 #include <net/inet_ecn.h>
  58 #include <net/net_namespace.h>
  59 #include <net/netns/generic.h>
  60
  61 MODULE_AUTHOR("Ville Nuorvala");
  62 MODULE_DESCRIPTION("IPv6 tunneling device");
  63 MODULE_LICENSE("GPL");
  64 MODULE_ALIAS_RTNL_LINK("ip6tnl");
  65 MODULE_ALIAS_NETDEV("ip6tnl0");
  66
  67 #ifdef IP6_TNL_DEBUG
  68 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
  69 #else
  70 #define IP6_TNL_TRACE(x...) do {;} while(0)
  71 #endif
  72
  73 #define HASH_SIZE_SHIFT  5
  74 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  75
  76 static bool log_ecn_error = true;
  77 module_param(log_ecn_error, bool, 0644);
  78 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  79
  80 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  81 {
  82         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  83
  84         return hash_32(hash, HASH_SIZE_SHIFT);
  85 }
  86
  87 static int ip6_tnl_dev_init(struct net_device *dev);
  88 static void ip6_tnl_dev_setup(struct net_device *dev);
  89 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  90
  91 static int ip6_tnl_net_id __read_mostly;
  92 struct ip6_tnl_net {
  93         /* the IPv6 tunnel fallback device */
  94         struct net_device *fb_tnl_dev;
  95         /* lists for storing tunnels in use */
  96         struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
  97         struct ip6_tnl __rcu *tnls_wc[1];
  98         struct ip6_tnl __rcu **tnls[2];
  99 };
 100
 101 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
 102 {
 103         struct pcpu_sw_netstats tmp, sum = { 0 };
 104         int i;
 105
 106         for_each_possible_cpu(i) {
 107                 unsigned int start;
 108                 const struct pcpu_sw_netstats *tstats =
 109                                                    per_cpu_ptr(dev->tstats, i);
 110
 111                 do {
 112                         start = u64_stats_fetch_begin_bh(&tstats->syncp);
 113                         tmp.rx_packets = tstats->rx_packets;
 114                         tmp.rx_bytes = tstats->rx_bytes;
 115                         tmp.tx_packets = tstats->tx_packets;
 116                         tmp.tx_bytes =  tstats->tx_bytes;
 117                 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
 118
 119                 sum.rx_packets += tmp.rx_packets;
 120                 sum.rx_bytes   += tmp.rx_bytes;
 121                 sum.tx_packets += tmp.tx_packets;
 122                 sum.tx_bytes   += tmp.tx_bytes;
 123         }
 124         dev->stats.rx_packets = sum.rx_packets;
 125         dev->stats.rx_bytes   = sum.rx_bytes;
 126         dev->stats.tx_packets = sum.tx_packets;
 127         dev->stats.tx_bytes   = sum.tx_bytes;
 128         return &dev->stats;
 129 }
 130
 131 /*
 132  * Locking : hash tables are protected by RCU and RTNL
 133  */
 134
 135 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 136 {
 137         struct dst_entry *dst = t->dst_cache;
 138
 139         if (dst && dst->obsolete &&
 140             dst->ops->check(dst, t->dst_cookie) == NULL) {
 141                 t->dst_cache = NULL;
 142                 dst_release(dst);
 143                 return NULL;
 144         }
 145
 146         return dst;
 147 }
 148 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
 149
 150 void ip6_tnl_dst_reset(struct ip6_tnl *t)
 151 {
 152         dst_release(t->dst_cache);
 153         t->dst_cache = NULL;
 154 }
 155 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
 156
 157 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
 158 {
 159         struct rt6_info *rt = (struct rt6_info *) dst;
 160         t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 161         dst_release(t->dst_cache);
 162         t->dst_cache = dst;
 163 }
 164 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
 165
 166 /**
 167  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 168  *   @remote: the address of the tunnel exit-point
 169  *   @local: the address of the tunnel entry-point
 170  *
 171  * Return:
 172  *   tunnel matching given end-points if found,
 173  *   else fallback tunnel if its device is up,
 174  *   else %NULL
 175  **/
 176
 177 #define for_each_ip6_tunnel_rcu(start) \
 178         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 179
 180 static struct ip6_tnl *
 181 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
 182 {
 183         unsigned int hash = HASH(remote, local);
 184         struct ip6_tnl *t;
 185         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 186
 187         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 188                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 189                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 190                     (t->dev->flags & IFF_UP))
 191                         return t;
 192         }
 193         t = rcu_dereference(ip6n->tnls_wc[0]);
 194         if (t && (t->dev->flags & IFF_UP))
 195                 return t;
 196
 197         return NULL;
 198 }
 199
 200 /**
 201  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 202  *   @p: parameters containing tunnel end-points
 203  *
 204  * Description:
 205  *   ip6_tnl_bucket() returns the head of the list matching the
 206  *   &struct in6_addr entries laddr and raddr in @p.
 207  *
 208  * Return: head of IPv6 tunnel list
 209  **/
 210
 211 static struct ip6_tnl __rcu **
 212 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 213 {
 214         const struct in6_addr *remote = &p->raddr;
 215         const struct in6_addr *local = &p->laddr;
 216         unsigned int h = 0;
 217         int prio = 0;
 218
 219         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 220                 prio = 1;
 221                 h = HASH(remote, local);
 222         }
 223         return &ip6n->tnls[prio][h];
 224 }
 225
 226 /**
 227  * ip6_tnl_link - add tunnel to hash table
 228  *   @t: tunnel to be added
 229  **/
 230
 231 static void
 232 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 233 {
 234         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 235
 236         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 237         rcu_assign_pointer(*tp, t);
 238 }
 239
 240 /**
 241  * ip6_tnl_unlink - remove tunnel from hash table
 242  *   @t: tunnel to be removed
 243  **/
 244
 245 static void
 246 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 247 {
 248         struct ip6_tnl __rcu **tp;
 249         struct ip6_tnl *iter;
 250
 251         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 252              (iter = rtnl_dereference(*tp)) != NULL;
 253              tp = &iter->next) {
 254                 if (t == iter) {
 255                         rcu_assign_pointer(*tp, t->next);
 256                         break;
 257                 }
 258         }
 259 }
 260
 261 static void ip6_dev_free(struct net_device *dev)
 262 {
 263         free_percpu(dev->tstats);
 264         free_netdev(dev);
 265 }
 266
 267 static int ip6_tnl_create2(struct net_device *dev)
 268 {
 269         struct ip6_tnl *t = netdev_priv(dev);
 270         struct net *net = dev_net(dev);
 271         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 272         int err;
 273
 274         t = netdev_priv(dev);
 275         err = ip6_tnl_dev_init(dev);
 276         if (err < 0)
 277                 goto out;
 278
 279         err = register_netdevice(dev);
 280         if (err < 0)
 281                 goto out;
 282
 283         strcpy(t->parms.name, dev->name);
 284         dev->rtnl_link_ops = &ip6_link_ops;
 285
 286         dev_hold(dev);
 287         ip6_tnl_link(ip6n, t);
 288         return 0;
 289
 290 out:
 291         return err;
 292 }
 293
 294 /**
 295  * ip6_tnl_create - create a new tunnel
 296  *   @p: tunnel parameters
 297  *   @pt: pointer to new tunnel
 298  *
 299  * Description:
 300  *   Create tunnel matching given parameters.
 301  *
 302  * Return:
 303  *   created tunnel or NULL
 304  **/
 305
 306 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 307 {
 308         struct net_device *dev;
 309         struct ip6_tnl *t;
 310         char name[IFNAMSIZ];
 311         int err;
 312
 313         if (p->name[0])
 314                 strlcpy(name, p->name, IFNAMSIZ);
 315         else
 316                 sprintf(name, "ip6tnl%%d");
 317
 318         dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
 319         if (dev == NULL)
 320                 goto failed;
 321
 322         dev_net_set(dev, net);
 323
 324         t = netdev_priv(dev);
 325         t->parms = *p;
 326         t->net = dev_net(dev);
 327         err = ip6_tnl_create2(dev);
 328         if (err < 0)
 329                 goto failed_free;
 330
 331         return t;
 332
 333 failed_free:
 334         ip6_dev_free(dev);
 335 failed:
 336         return NULL;
 337 }
 338
 339 /**
 340  * ip6_tnl_locate - find or create tunnel matching given parameters
 341  *   @p: tunnel parameters
 342  *   @create: != 0 if allowed to create new tunnel if no match found
 343  *
 344  * Description:
 345  *   ip6_tnl_locate() first tries to locate an existing tunnel
 346  *   based on @parms. If this is unsuccessful, but @create is set a new
 347  *   tunnel device is created and registered for use.
 348  *
 349  * Return:
 350  *   matching tunnel or NULL
 351  **/
 352
 353 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 354                 struct __ip6_tnl_parm *p, int create)
 355 {
 356         const struct in6_addr *remote = &p->raddr;
 357         const struct in6_addr *local = &p->laddr;
 358         struct ip6_tnl __rcu **tp;
 359         struct ip6_tnl *t;
 360         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 361
 362         for (tp = ip6_tnl_bucket(ip6n, p);
 363              (t = rtnl_dereference(*tp)) != NULL;
 364              tp = &t->next) {
 365                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 366                     ipv6_addr_equal(remote, &t->parms.raddr))
 367                         return t;
 368         }
 369         if (!create)
 370                 return NULL;
 371         return ip6_tnl_create(net, p);
 372 }
 373
 374 /**
 375  * ip6_tnl_dev_uninit - tunnel device uninitializer
 376  *   @dev: the device to be destroyed
 377  *
 378  * Description:
 379  *   ip6_tnl_dev_uninit() removes tunnel from its list
 380  **/
 381
 382 static void
 383 ip6_tnl_dev_uninit(struct net_device *dev)
 384 {
 385         struct ip6_tnl *t = netdev_priv(dev);
 386         struct net *net = t->net;
 387         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 388
 389         if (dev == ip6n->fb_tnl_dev)
 390                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 391         else
 392                 ip6_tnl_unlink(ip6n, t);
 393         ip6_tnl_dst_reset(t);
 394         dev_put(dev);
 395 }
 396
 397 /**
 398  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 399  *   @skb: received socket buffer
 400  *
 401  * Return:
 402  *   0 if none was found,
 403  *   else index to encapsulation limit
 404  **/
 405
 406 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 407 {
 408         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
 409         __u8 nexthdr = ipv6h->nexthdr;
 410         __u16 off = sizeof (*ipv6h);
 411
 412         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 413                 __u16 optlen = 0;
 414                 struct ipv6_opt_hdr *hdr;
 415                 if (raw + off + sizeof (*hdr) > skb->data &&
 416                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 417                         break;
 418
 419                 hdr = (struct ipv6_opt_hdr *) (raw + off);
 420                 if (nexthdr == NEXTHDR_FRAGMENT) {
 421                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 422                         if (frag_hdr->frag_off)
 423                                 break;
 424                         optlen = 8;
 425                 } else if (nexthdr == NEXTHDR_AUTH) {
 426                         optlen = (hdr->hdrlen + 2) << 2;
 427                 } else {
 428                         optlen = ipv6_optlen(hdr);
 429                 }
 430                 if (nexthdr == NEXTHDR_DEST) {
 431                         __u16 i = off + 2;
 432                         while (1) {
 433                                 struct ipv6_tlv_tnl_enc_lim *tel;
 434
 435                                 /* No more room for encapsulation limit */
 436                                 if (i + sizeof (*tel) > off + optlen)
 437                                         break;
 438
 439                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 440                                 /* return index of option if found and valid */
 441                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 442                                     tel->length == 1)
 443                                         return i;
 444                                 /* else jump to next option */
 445                                 if (tel->type)
 446                                         i += tel->length + 2;
 447                                 else
 448                                         i++;
 449                         }
 450                 }
 451                 nexthdr = hdr->nexthdr;
 452                 off += optlen;
 453         }
 454         return 0;
 455 }
 456 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 457
 458 /**
 459  * ip6_tnl_err - tunnel error handler
 460  *
 461  * Description:
 462  *   ip6_tnl_err() should handle errors in the tunnel according
 463  *   to the specifications in RFC 2473.
 464  **/
 465
 466 static int
 467 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 468             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 469 {
 470         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
 471         struct ip6_tnl *t;
 472         int rel_msg = 0;
 473         u8 rel_type = ICMPV6_DEST_UNREACH;
 474         u8 rel_code = ICMPV6_ADDR_UNREACH;
 475         __u32 rel_info = 0;
 476         __u16 len;
 477         int err = -ENOENT;
 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         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
 485                                         &ipv6h->saddr)) == NULL)
 486                 goto out;
 487
 488         if (t->parms.proto != ipproto && t->parms.proto != 0)
 489                 goto out;
 490
 491         err = 0;
 492
 493         switch (*type) {
 494                 __u32 teli;
 495                 struct ipv6_tlv_tnl_enc_lim *tel;
 496                 __u32 mtu;
 497         case ICMPV6_DEST_UNREACH:
 498                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 499                                      t->parms.name);
 500                 rel_msg = 1;
 501                 break;
 502         case ICMPV6_TIME_EXCEED:
 503                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 504                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 505                                              t->parms.name);
 506                         rel_msg = 1;
 507                 }
 508                 break;
 509         case ICMPV6_PARAMPROB:
 510                 teli = 0;
 511                 if ((*code) == ICMPV6_HDR_FIELD)
 512                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 513
 514                 if (teli && teli == *info - 2) {
 515                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 516                         if (tel->encap_limit == 0) {
 517                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 518                                                      t->parms.name);
 519                                 rel_msg = 1;
 520                         }
 521                 } else {
 522                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 523                                              t->parms.name);
 524                 }
 525                 break;
 526         case ICMPV6_PKT_TOOBIG:
 527                 mtu = *info - offset;
 528                 if (mtu < IPV6_MIN_MTU)
 529                         mtu = IPV6_MIN_MTU;
 530                 t->dev->mtu = mtu;
 531
 532                 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 533                         rel_type = ICMPV6_PKT_TOOBIG;
 534                         rel_code = 0;
 535                         rel_info = mtu;
 536                         rel_msg = 1;
 537                 }
 538                 break;
 539         }
 540
 541         *type = rel_type;
 542         *code = rel_code;
 543         *info = rel_info;
 544         *msg = rel_msg;
 545
 546 out:
 547         rcu_read_unlock();
 548         return err;
 549 }
 550
 551 static int
 552 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 553            u8 type, u8 code, int offset, __be32 info)
 554 {
 555         int rel_msg = 0;
 556         u8 rel_type = type;
 557         u8 rel_code = code;
 558         __u32 rel_info = ntohl(info);
 559         int err;
 560         struct sk_buff *skb2;
 561         const struct iphdr *eiph;
 562         struct rtable *rt;
 563         struct flowi4 fl4;
 564
 565         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 566                           &rel_msg, &rel_info, offset);
 567         if (err < 0)
 568                 return err;
 569
 570         if (rel_msg == 0)
 571                 return 0;
 572
 573         switch (rel_type) {
 574         case ICMPV6_DEST_UNREACH:
 575                 if (rel_code != ICMPV6_ADDR_UNREACH)
 576                         return 0;
 577                 rel_type = ICMP_DEST_UNREACH;
 578                 rel_code = ICMP_HOST_UNREACH;
 579                 break;
 580         case ICMPV6_PKT_TOOBIG:
 581                 if (rel_code != 0)
 582                         return 0;
 583                 rel_type = ICMP_DEST_UNREACH;
 584                 rel_code = ICMP_FRAG_NEEDED;
 585                 break;
 586         case NDISC_REDIRECT:
 587                 rel_type = ICMP_REDIRECT;
 588                 rel_code = ICMP_REDIR_HOST;
 589         default:
 590                 return 0;
 591         }
 592
 593         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 594                 return 0;
 595
 596         skb2 = skb_clone(skb, GFP_ATOMIC);
 597         if (!skb2)
 598                 return 0;
 599
 600         skb_dst_drop(skb2);
 601
 602         skb_pull(skb2, offset);
 603         skb_reset_network_header(skb2);
 604         eiph = ip_hdr(skb2);
 605
 606         /* Try to guess incoming interface */
 607         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 608                                    eiph->saddr, 0,
 609                                    0, 0,
 610                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 611         if (IS_ERR(rt))
 612                 goto out;
 613
 614         skb2->dev = rt->dst.dev;
 615
 616         /* route "incoming" packet */
 617         if (rt->rt_flags & RTCF_LOCAL) {
 618                 ip_rt_put(rt);
 619                 rt = NULL;
 620                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 621                                            eiph->daddr, eiph->saddr,
 622                                            0, 0,
 623                                            IPPROTO_IPIP,
 624                                            RT_TOS(eiph->tos), 0);
 625                 if (IS_ERR(rt) ||
 626                     rt->dst.dev->type != ARPHRD_TUNNEL) {
 627                         if (!IS_ERR(rt))
 628                                 ip_rt_put(rt);
 629                         goto out;
 630                 }
 631                 skb_dst_set(skb2, &rt->dst);
 632         } else {
 633                 ip_rt_put(rt);
 634                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 635                                    skb2->dev) ||
 636                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 637                         goto out;
 638         }
 639
 640         /* change mtu on this route */
 641         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 642                 if (rel_info > dst_mtu(skb_dst(skb2)))
 643                         goto out;
 644
 645                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
 646         }
 647         if (rel_type == ICMP_REDIRECT)
 648                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
 649
 650         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 651
 652 out:
 653         kfree_skb(skb2);
 654         return 0;
 655 }
 656
 657 static int
 658 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 659            u8 type, u8 code, int offset, __be32 info)
 660 {
 661         int rel_msg = 0;
 662         u8 rel_type = type;
 663         u8 rel_code = code;
 664         __u32 rel_info = ntohl(info);
 665         int err;
 666
 667         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 668                           &rel_msg, &rel_info, offset);
 669         if (err < 0)
 670                 return err;
 671
 672         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 673                 struct rt6_info *rt;
 674                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 675
 676                 if (!skb2)
 677                         return 0;
 678
 679                 skb_dst_drop(skb2);
 680                 skb_pull(skb2, offset);
 681                 skb_reset_network_header(skb2);
 682
 683                 /* Try to guess incoming interface */
 684                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 685                                 NULL, 0, 0);
 686
 687                 if (rt && rt->dst.dev)
 688                         skb2->dev = rt->dst.dev;
 689
 690                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 691
 692                 ip6_rt_put(rt);
 693
 694                 kfree_skb(skb2);
 695         }
 696
 697         return 0;
 698 }
 699
 700 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 701                                        const struct ipv6hdr *ipv6h,
 702                                        struct sk_buff *skb)
 703 {
 704         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 705
 706         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 707                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 708
 709         return IP6_ECN_decapsulate(ipv6h, skb);
 710 }
 711
 712 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 713                                        const struct ipv6hdr *ipv6h,
 714                                        struct sk_buff *skb)
 715 {
 716         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 717                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 718
 719         return IP6_ECN_decapsulate(ipv6h, skb);
 720 }
 721
 722 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 723                              const struct in6_addr *laddr,
 724                              const struct in6_addr *raddr)
 725 {
 726         struct __ip6_tnl_parm *p = &t->parms;
 727         int ltype = ipv6_addr_type(laddr);
 728         int rtype = ipv6_addr_type(raddr);
 729         __u32 flags = 0;
 730
 731         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 732                 flags = IP6_TNL_F_CAP_PER_PACKET;
 733         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 734                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 735                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 736                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 737                 if (ltype&IPV6_ADDR_UNICAST)
 738                         flags |= IP6_TNL_F_CAP_XMIT;
 739                 if (rtype&IPV6_ADDR_UNICAST)
 740                         flags |= IP6_TNL_F_CAP_RCV;
 741         }
 742         return flags;
 743 }
 744 EXPORT_SYMBOL(ip6_tnl_get_cap);
 745
 746 /* called with rcu_read_lock() */
 747 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 748                                   const struct in6_addr *laddr,
 749                                   const struct in6_addr *raddr)
 750 {
 751         struct __ip6_tnl_parm *p = &t->parms;
 752         int ret = 0;
 753         struct net *net = t->net;
 754
 755         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 756             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 757              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 758                 struct net_device *ldev = NULL;
 759
 760                 if (p->link)
 761                         ldev = dev_get_by_index_rcu(net, p->link);
 762
 763                 if ((ipv6_addr_is_multicast(laddr) ||
 764                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
 765                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
 766                         ret = 1;
 767         }
 768         return ret;
 769 }
 770 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 771
 772 /**
 773  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 774  *   @skb: received socket buffer
 775  *   @protocol: ethernet protocol ID
 776  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 777  *
 778  * Return: 0
 779  **/
 780
 781 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 782                        __u8 ipproto,
 783                        int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 784                                                    const struct ipv6hdr *ipv6h,
 785                                                    struct sk_buff *skb))
 786 {
 787         struct ip6_tnl *t;
 788         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 789         int err;
 790
 791         rcu_read_lock();
 792
 793         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
 794                                         &ipv6h->daddr)) != NULL) {
 795                 struct pcpu_sw_netstats *tstats;
 796
 797                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
 798                         rcu_read_unlock();
 799                         goto discard;
 800                 }
 801
 802                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 803                         rcu_read_unlock();
 804                         goto discard;
 805                 }
 806
 807                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 808                         t->dev->stats.rx_dropped++;
 809                         rcu_read_unlock();
 810                         goto discard;
 811                 }
 812                 skb->mac_header = skb->network_header;
 813                 skb_reset_network_header(skb);
 814                 skb->protocol = htons(protocol);
 815                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 816
 817                 __skb_tunnel_rx(skb, t->dev, t->net);
 818
 819                 err = dscp_ecn_decapsulate(t, ipv6h, skb);
 820                 if (unlikely(err)) {
 821                         if (log_ecn_error)
 822                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 823                                                      &ipv6h->saddr,
 824                                                      ipv6_get_dsfield(ipv6h));
 825                         if (err > 1) {
 826                                 ++t->dev->stats.rx_frame_errors;
 827                                 ++t->dev->stats.rx_errors;
 828                                 rcu_read_unlock();
 829                                 goto discard;
 830                         }
 831                 }
 832
 833                 tstats = this_cpu_ptr(t->dev->tstats);
 834                 u64_stats_update_begin(&tstats->syncp);
 835                 tstats->rx_packets++;
 836                 tstats->rx_bytes += skb->len;
 837                 u64_stats_update_end(&tstats->syncp);
 838
 839                 netif_rx(skb);
 840
 841                 rcu_read_unlock();
 842                 return 0;
 843         }
 844         rcu_read_unlock();
 845         return 1;
 846
 847 discard:
 848         kfree_skb(skb);
 849         return 0;
 850 }
 851
 852 static int ip4ip6_rcv(struct sk_buff *skb)
 853 {
 854         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 855                            ip4ip6_dscp_ecn_decapsulate);
 856 }
 857
 858 static int ip6ip6_rcv(struct sk_buff *skb)
 859 {
 860         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 861                            ip6ip6_dscp_ecn_decapsulate);
 862 }
 863
 864 struct ipv6_tel_txoption {
 865         struct ipv6_txoptions ops;
 866         __u8 dst_opt[8];
 867 };
 868
 869 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 870 {
 871         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 872
 873         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 874         opt->dst_opt[3] = 1;
 875         opt->dst_opt[4] = encap_limit;
 876         opt->dst_opt[5] = IPV6_TLV_PADN;
 877         opt->dst_opt[6] = 1;
 878
 879         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 880         opt->ops.opt_nflen = 8;
 881 }
 882
 883 /**
 884  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 885  *   @t: the outgoing tunnel device
 886  *   @hdr: IPv6 header from the incoming packet
 887  *
 888  * Description:
 889  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 890  *   doesn't match source of incoming packet.
 891  *
 892  * Return:
 893  *   1 if conflict,
 894  *   0 else
 895  **/
 896
 897 static inline bool
 898 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 899 {
 900         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 901 }
 902
 903 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 904 {
 905         struct __ip6_tnl_parm *p = &t->parms;
 906         int ret = 0;
 907         struct net *net = t->net;
 908
 909         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 910                 struct net_device *ldev = NULL;
 911
 912                 rcu_read_lock();
 913                 if (p->link)
 914                         ldev = dev_get_by_index_rcu(net, p->link);
 915
 916                 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
 917                         pr_warn("%s xmit: Local address not yet configured!\n",
 918                                 p->name);
 919                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
 920                          unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
 921                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
 922                                 p->name);
 923                 else
 924                         ret = 1;
 925                 rcu_read_unlock();
 926         }
 927         return ret;
 928 }
 929 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
 930
 931 /**
 932  * ip6_tnl_xmit2 - encapsulate packet and send
 933  *   @skb: the outgoing socket buffer
 934  *   @dev: the outgoing tunnel device
 935  *   @dsfield: dscp code for outer header
 936  *   @fl: flow of tunneled packet
 937  *   @encap_limit: encapsulation limit
 938  *   @pmtu: Path MTU is stored if packet is too big
 939  *
 940  * Description:
 941  *   Build new header and do some sanity checks on the packet before sending
 942  *   it.
 943  *
 944  * Return:
 945  *   0 on success
 946  *   -1 fail
 947  *   %-EMSGSIZE message too big. return mtu in this case.
 948  **/
 949
 950 static int ip6_tnl_xmit2(struct sk_buff *skb,
 951                          struct net_device *dev,
 952                          __u8 dsfield,
 953                          struct flowi6 *fl6,
 954                          int encap_limit,
 955                          __u32 *pmtu)
 956 {
 957         struct ip6_tnl *t = netdev_priv(dev);
 958         struct net *net = t->net;
 959         struct net_device_stats *stats = &t->dev->stats;
 960         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 961         struct ipv6_tel_txoption opt;
 962         struct dst_entry *dst = NULL, *ndst = NULL;
 963         struct net_device *tdev;
 964         int mtu;
 965         unsigned int max_headroom = sizeof(struct ipv6hdr);
 966         u8 proto;
 967         int err = -1;
 968
 969         if (!fl6->flowi6_mark)
 970                 dst = ip6_tnl_dst_check(t);
 971         if (!dst) {
 972                 ndst = ip6_route_output(net, NULL, fl6);
 973
 974                 if (ndst->error)
 975                         goto tx_err_link_failure;
 976                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 977                 if (IS_ERR(ndst)) {
 978                         err = PTR_ERR(ndst);
 979                         ndst = NULL;
 980                         goto tx_err_link_failure;
 981                 }
 982                 dst = ndst;
 983         }
 984
 985         tdev = dst->dev;
 986
 987         if (tdev == dev) {
 988                 stats->collisions++;
 989                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 990                                      t->parms.name);
 991                 goto tx_err_dst_release;
 992         }
 993         mtu = dst_mtu(dst) - sizeof (*ipv6h);
 994         if (encap_limit >= 0) {
 995                 max_headroom += 8;
 996                 mtu -= 8;
 997         }
 998         if (mtu < IPV6_MIN_MTU)
 999                 mtu = IPV6_MIN_MTU;
1000         if (skb_dst(skb))
1001                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1002         if (skb->len > mtu) {
1003                 *pmtu = mtu;
1004                 err = -EMSGSIZE;
1005                 goto tx_err_dst_release;
1006         }
1007
1008         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1009
1010         /*
1011          * Okay, now see if we can stuff it in the buffer as-is.
1012          */
1013         max_headroom += LL_RESERVED_SPACE(tdev);
1014
1015         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1016             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1017                 struct sk_buff *new_skb;
1018
1019                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1020                         goto tx_err_dst_release;
1021
1022                 if (skb->sk)
1023                         skb_set_owner_w(new_skb, skb->sk);
1024                 consume_skb(skb);
1025                 skb = new_skb;
1026         }
1027         if (fl6->flowi6_mark) {
1028                 skb_dst_set(skb, dst);
1029                 ndst = NULL;
1030         } else {
1031                 skb_dst_set_noref(skb, dst);
1032         }
1033         skb->transport_header = skb->network_header;
1034
1035         proto = fl6->flowi6_proto;
1036         if (encap_limit >= 0) {
1037                 init_tel_txopt(&opt, encap_limit);
1038                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1039         }
1040
1041         if (likely(!skb->encapsulation)) {
1042                 skb_reset_inner_headers(skb);
1043                 skb->encapsulation = 1;
1044         }
1045
1046         skb_push(skb, sizeof(struct ipv6hdr));
1047         skb_reset_network_header(skb);
1048         ipv6h = ipv6_hdr(skb);
1049         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
1050         ipv6h->hop_limit = t->parms.hop_limit;
1051         ipv6h->nexthdr = proto;
1052         ipv6h->saddr = fl6->saddr;
1053         ipv6h->daddr = fl6->daddr;
1054         ip6tunnel_xmit(skb, dev);
1055         if (ndst)
1056                 ip6_tnl_dst_store(t, ndst);
1057         return 0;
1058 tx_err_link_failure:
1059         stats->tx_carrier_errors++;
1060         dst_link_failure(skb);
1061 tx_err_dst_release:
1062         dst_release(ndst);
1063         return err;
1064 }
1065
1066 static inline int
1067 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1068 {
1069         struct ip6_tnl *t = netdev_priv(dev);
1070         const struct iphdr  *iph = ip_hdr(skb);
1071         int encap_limit = -1;
1072         struct flowi6 fl6;
1073         __u8 dsfield;
1074         __u32 mtu;
1075         int err;
1076
1077         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1078             !ip6_tnl_xmit_ctl(t))
1079                 return -1;
1080
1081         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1082                 encap_limit = t->parms.encap_limit;
1083
1084         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1085         fl6.flowi6_proto = IPPROTO_IPIP;
1086
1087         dsfield = ipv4_get_dsfield(iph);
1088
1089         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1090                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1091                                           & IPV6_TCLASS_MASK;
1092         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1093                 fl6.flowi6_mark = skb->mark;
1094
1095         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1096         if (err != 0) {
1097                 /* XXX: send ICMP error even if DF is not set. */
1098                 if (err == -EMSGSIZE)
1099                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1100                                   htonl(mtu));
1101                 return -1;
1102         }
1103
1104         return 0;
1105 }
1106
1107 static inline int
1108 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1109 {
1110         struct ip6_tnl *t = netdev_priv(dev);
1111         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1112         int encap_limit = -1;
1113         __u16 offset;
1114         struct flowi6 fl6;
1115         __u8 dsfield;
1116         __u32 mtu;
1117         int err;
1118
1119         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1120             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1121                 return -1;
1122
1123         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1124         if (offset > 0) {
1125                 struct ipv6_tlv_tnl_enc_lim *tel;
1126                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1127                 if (tel->encap_limit == 0) {
1128                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1129                                     ICMPV6_HDR_FIELD, offset + 2);
1130                         return -1;
1131                 }
1132                 encap_limit = tel->encap_limit - 1;
1133         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1134                 encap_limit = t->parms.encap_limit;
1135
1136         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1137         fl6.flowi6_proto = IPPROTO_IPV6;
1138
1139         dsfield = ipv6_get_dsfield(ipv6h);
1140         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1141                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1142         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1143                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1144         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1145                 fl6.flowi6_mark = skb->mark;
1146
1147         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1148         if (err != 0) {
1149                 if (err == -EMSGSIZE)
1150                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1151                 return -1;
1152         }
1153
1154         return 0;
1155 }
1156
1157 static netdev_tx_t
1158 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1159 {
1160         struct ip6_tnl *t = netdev_priv(dev);
1161         struct net_device_stats *stats = &t->dev->stats;
1162         int ret;
1163
1164         switch (skb->protocol) {
1165         case htons(ETH_P_IP):
1166                 ret = ip4ip6_tnl_xmit(skb, dev);
1167                 break;
1168         case htons(ETH_P_IPV6):
1169                 ret = ip6ip6_tnl_xmit(skb, dev);
1170                 break;
1171         default:
1172                 goto tx_err;
1173         }
1174
1175         if (ret < 0)
1176                 goto tx_err;
1177
1178         return NETDEV_TX_OK;
1179
1180 tx_err:
1181         stats->tx_errors++;
1182         stats->tx_dropped++;
1183         kfree_skb(skb);
1184         return NETDEV_TX_OK;
1185 }
1186
1187 static void ip6_tnl_link_config(struct ip6_tnl *t)
1188 {
1189         struct net_device *dev = t->dev;
1190         struct __ip6_tnl_parm *p = &t->parms;
1191         struct flowi6 *fl6 = &t->fl.u.ip6;
1192
1193         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1194         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1195
1196         /* Set up flowi template */
1197         fl6->saddr = p->laddr;
1198         fl6->daddr = p->raddr;
1199         fl6->flowi6_oif = p->link;
1200         fl6->flowlabel = 0;
1201
1202         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1203                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1204         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1205                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1206
1207         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1208         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1209
1210         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1211                 dev->flags |= IFF_POINTOPOINT;
1212         else
1213                 dev->flags &= ~IFF_POINTOPOINT;
1214
1215         dev->iflink = p->link;
1216
1217         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1218                 int strict = (ipv6_addr_type(&p->raddr) &
1219                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1220
1221                 struct rt6_info *rt = rt6_lookup(t->net,
1222                                                  &p->raddr, &p->laddr,
1223                                                  p->link, strict);
1224
1225                 if (rt == NULL)
1226                         return;
1227
1228                 if (rt->dst.dev) {
1229                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1230                                 sizeof (struct ipv6hdr);
1231
1232                         dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1233                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1234                                 dev->mtu-=8;
1235
1236                         if (dev->mtu < IPV6_MIN_MTU)
1237                                 dev->mtu = IPV6_MIN_MTU;
1238                 }
1239                 ip6_rt_put(rt);
1240         }
1241 }
1242
1243 /**
1244  * ip6_tnl_change - update the tunnel parameters
1245  *   @t: tunnel to be changed
1246  *   @p: tunnel configuration parameters
1247  *
1248  * Description:
1249  *   ip6_tnl_change() updates the tunnel parameters
1250  **/
1251
1252 static int
1253 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1254 {
1255         t->parms.laddr = p->laddr;
1256         t->parms.raddr = p->raddr;
1257         t->parms.flags = p->flags;
1258         t->parms.hop_limit = p->hop_limit;
1259         t->parms.encap_limit = p->encap_limit;
1260         t->parms.flowinfo = p->flowinfo;
1261         t->parms.link = p->link;
1262         t->parms.proto = p->proto;
1263         ip6_tnl_dst_reset(t);
1264         ip6_tnl_link_config(t);
1265         return 0;
1266 }
1267
1268 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1269 {
1270         struct net *net = t->net;
1271         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1272         int err;
1273
1274         ip6_tnl_unlink(ip6n, t);
1275         synchronize_net();
1276         err = ip6_tnl_change(t, p);
1277         ip6_tnl_link(ip6n, t);
1278         netdev_state_change(t->dev);
1279         return err;
1280 }
1281
1282 static void
1283 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1284 {
1285         p->laddr = u->laddr;
1286         p->raddr = u->raddr;
1287         p->flags = u->flags;
1288         p->hop_limit = u->hop_limit;
1289         p->encap_limit = u->encap_limit;
1290         p->flowinfo = u->flowinfo;
1291         p->link = u->link;
1292         p->proto = u->proto;
1293         memcpy(p->name, u->name, sizeof(u->name));
1294 }
1295
1296 static void
1297 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1298 {
1299         u->laddr = p->laddr;
1300         u->raddr = p->raddr;
1301         u->flags = p->flags;
1302         u->hop_limit = p->hop_limit;
1303         u->encap_limit = p->encap_limit;
1304         u->flowinfo = p->flowinfo;
1305         u->link = p->link;
1306         u->proto = p->proto;
1307         memcpy(u->name, p->name, sizeof(u->name));
1308 }
1309
1310 /**
1311  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1312  *   @dev: virtual device associated with tunnel
1313  *   @ifr: parameters passed from userspace
1314  *   @cmd: command to be performed
1315  *
1316  * Description:
1317  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1318  *   from userspace.
1319  *
1320  *   The possible commands are the following:
1321  *     %SIOCGETTUNNEL: get tunnel parameters for device
1322  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1323  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1324  *     %SIOCDELTUNNEL: delete tunnel
1325  *
1326  *   The fallback device "ip6tnl0", created during module
1327  *   initialization, can be used for creating other tunnel devices.
1328  *
1329  * Return:
1330  *   0 on success,
1331  *   %-EFAULT if unable to copy data to or from userspace,
1332  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1333  *   %-EINVAL if passed tunnel parameters are invalid,
1334  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1335  *   %-ENODEV if attempting to change or delete a nonexisting device
1336  **/
1337
1338 static int
1339 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1340 {
1341         int err = 0;
1342         struct ip6_tnl_parm p;
1343         struct __ip6_tnl_parm p1;
1344         struct ip6_tnl *t = NULL;
1345         struct net *net = dev_net(dev);
1346         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1347
1348         switch (cmd) {
1349         case SIOCGETTUNNEL:
1350                 if (dev == ip6n->fb_tnl_dev) {
1351                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1352                                 err = -EFAULT;
1353                                 break;
1354                         }
1355                         ip6_tnl_parm_from_user(&p1, &p);
1356                         t = ip6_tnl_locate(net, &p1, 0);
1357                 } else {
1358                         memset(&p, 0, sizeof(p));
1359                 }
1360                 if (t == NULL)
1361                         t = netdev_priv(dev);
1362                 ip6_tnl_parm_to_user(&p, &t->parms);
1363                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1364                         err = -EFAULT;
1365                 }
1366                 break;
1367         case SIOCADDTUNNEL:
1368         case SIOCCHGTUNNEL:
1369                 err = -EPERM;
1370                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1371                         break;
1372                 err = -EFAULT;
1373                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1374                         break;
1375                 err = -EINVAL;
1376                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1377                     p.proto != 0)
1378                         break;
1379                 ip6_tnl_parm_from_user(&p1, &p);
1380                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1381                 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1382                         if (t != NULL) {
1383                                 if (t->dev != dev) {
1384                                         err = -EEXIST;
1385                                         break;
1386                                 }
1387                         } else
1388                                 t = netdev_priv(dev);
1389
1390                         err = ip6_tnl_update(t, &p1);
1391                 }
1392                 if (t) {
1393                         err = 0;
1394                         ip6_tnl_parm_to_user(&p, &t->parms);
1395                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1396                                 err = -EFAULT;
1397
1398                 } else
1399                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1400                 break;
1401         case SIOCDELTUNNEL:
1402                 err = -EPERM;
1403                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1404                         break;
1405
1406                 if (dev == ip6n->fb_tnl_dev) {
1407                         err = -EFAULT;
1408                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1409                                 break;
1410                         err = -ENOENT;
1411                         ip6_tnl_parm_from_user(&p1, &p);
1412                         t = ip6_tnl_locate(net, &p1, 0);
1413                         if (t == NULL)
1414                                 break;
1415                         err = -EPERM;
1416                         if (t->dev == ip6n->fb_tnl_dev)
1417                                 break;
1418                         dev = t->dev;
1419                 }
1420                 err = 0;
1421                 unregister_netdevice(dev);
1422                 break;
1423         default:
1424                 err = -EINVAL;
1425         }
1426         return err;
1427 }
1428
1429 /**
1430  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1431  *   @dev: virtual device associated with tunnel
1432  *   @new_mtu: the new mtu
1433  *
1434  * Return:
1435  *   0 on success,
1436  *   %-EINVAL if mtu too small
1437  **/
1438
1439 static int
1440 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1441 {
1442         struct ip6_tnl *tnl = netdev_priv(dev);
1443
1444         if (tnl->parms.proto == IPPROTO_IPIP) {
1445                 if (new_mtu < 68)
1446                         return -EINVAL;
1447         } else {
1448                 if (new_mtu < IPV6_MIN_MTU)
1449                         return -EINVAL;
1450         }
1451         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1452                 return -EINVAL;
1453         dev->mtu = new_mtu;
1454         return 0;
1455 }
1456
1457
1458 static const struct net_device_ops ip6_tnl_netdev_ops = {
1459         .ndo_uninit     = ip6_tnl_dev_uninit,
1460         .ndo_start_xmit = ip6_tnl_xmit,
1461         .ndo_do_ioctl   = ip6_tnl_ioctl,
1462         .ndo_change_mtu = ip6_tnl_change_mtu,
1463         .ndo_get_stats  = ip6_get_stats,
1464 };
1465
1466
1467 /**
1468  * ip6_tnl_dev_setup - setup virtual tunnel device
1469  *   @dev: virtual device associated with tunnel
1470  *
1471  * Description:
1472  *   Initialize function pointers and device parameters
1473  **/
1474
1475 static void ip6_tnl_dev_setup(struct net_device *dev)
1476 {
1477         struct ip6_tnl *t;
1478
1479         dev->netdev_ops = &ip6_tnl_netdev_ops;
1480         dev->destructor = ip6_dev_free;
1481
1482         dev->type = ARPHRD_TUNNEL6;
1483         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1484         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1485         t = netdev_priv(dev);
1486         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1487                 dev->mtu-=8;
1488         dev->flags |= IFF_NOARP;
1489         dev->addr_len = sizeof(struct in6_addr);
1490         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1491         /* This perm addr will be used as interface identifier by IPv6 */
1492         dev->addr_assign_type = NET_ADDR_RANDOM;
1493         eth_random_addr(dev->perm_addr);
1494 }
1495
1496
1497 /**
1498  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1499  *   @dev: virtual device associated with tunnel
1500  **/
1501
1502 static inline int
1503 ip6_tnl_dev_init_gen(struct net_device *dev)
1504 {
1505         struct ip6_tnl *t = netdev_priv(dev);
1506         int i;
1507
1508         t->dev = dev;
1509         t->net = dev_net(dev);
1510         dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1511         if (!dev->tstats)
1512                 return -ENOMEM;
1513
1514         for_each_possible_cpu(i) {
1515                 struct pcpu_sw_netstats *ip6_tnl_stats;
1516                 ip6_tnl_stats = per_cpu_ptr(dev->tstats, i);
1517                 u64_stats_init(&ip6_tnl_stats->syncp);
1518         }
1519         return 0;
1520 }
1521
1522 /**
1523  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1524  *   @dev: virtual device associated with tunnel
1525  **/
1526
1527 static int ip6_tnl_dev_init(struct net_device *dev)
1528 {
1529         struct ip6_tnl *t = netdev_priv(dev);
1530         int err = ip6_tnl_dev_init_gen(dev);
1531
1532         if (err)
1533                 return err;
1534         ip6_tnl_link_config(t);
1535         return 0;
1536 }
1537
1538 /**
1539  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1540  *   @dev: fallback device
1541  *
1542  * Return: 0
1543  **/
1544
1545 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1546 {
1547         struct ip6_tnl *t = netdev_priv(dev);
1548         struct net *net = dev_net(dev);
1549         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1550         int err = ip6_tnl_dev_init_gen(dev);
1551
1552         if (err)
1553                 return err;
1554
1555         t->parms.proto = IPPROTO_IPV6;
1556         dev_hold(dev);
1557
1558         ip6_tnl_link_config(t);
1559
1560         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1561         return 0;
1562 }
1563
1564 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1565 {
1566         u8 proto;
1567
1568         if (!data || !data[IFLA_IPTUN_PROTO])
1569                 return 0;
1570
1571         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1572         if (proto != IPPROTO_IPV6 &&
1573             proto != IPPROTO_IPIP &&
1574             proto != 0)
1575                 return -EINVAL;
1576
1577         return 0;
1578 }
1579
1580 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1581                                   struct __ip6_tnl_parm *parms)
1582 {
1583         memset(parms, 0, sizeof(*parms));
1584
1585         if (!data)
1586                 return;
1587
1588         if (data[IFLA_IPTUN_LINK])
1589                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1590
1591         if (data[IFLA_IPTUN_LOCAL])
1592                 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1593                            sizeof(struct in6_addr));
1594
1595         if (data[IFLA_IPTUN_REMOTE])
1596                 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1597                            sizeof(struct in6_addr));
1598
1599         if (data[IFLA_IPTUN_TTL])
1600                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1601
1602         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1603                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1604
1605         if (data[IFLA_IPTUN_FLOWINFO])
1606                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1607
1608         if (data[IFLA_IPTUN_FLAGS])
1609                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1610
1611         if (data[IFLA_IPTUN_PROTO])
1612                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1613 }
1614
1615 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1616                            struct nlattr *tb[], struct nlattr *data[])
1617 {
1618         struct net *net = dev_net(dev);
1619         struct ip6_tnl *nt;
1620
1621         nt = netdev_priv(dev);
1622         ip6_tnl_netlink_parms(data, &nt->parms);
1623
1624         if (ip6_tnl_locate(net, &nt->parms, 0))
1625                 return -EEXIST;
1626
1627         return ip6_tnl_create2(dev);
1628 }
1629
1630 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1631                               struct nlattr *data[])
1632 {
1633         struct ip6_tnl *t = netdev_priv(dev);
1634         struct __ip6_tnl_parm p;
1635         struct net *net = t->net;
1636         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1637
1638         if (dev == ip6n->fb_tnl_dev)
1639                 return -EINVAL;
1640
1641         ip6_tnl_netlink_parms(data, &p);
1642
1643         t = ip6_tnl_locate(net, &p, 0);
1644
1645         if (t) {
1646                 if (t->dev != dev)
1647                         return -EEXIST;
1648         } else
1649                 t = netdev_priv(dev);
1650
1651         return ip6_tnl_update(t, &p);
1652 }
1653
1654 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1655 {
1656         struct net *net = dev_net(dev);
1657         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1658
1659         if (dev != ip6n->fb_tnl_dev)
1660                 unregister_netdevice_queue(dev, head);
1661 }
1662
1663 static size_t ip6_tnl_get_size(const struct net_device *dev)
1664 {
1665         return
1666                 /* IFLA_IPTUN_LINK */
1667                 nla_total_size(4) +
1668                 /* IFLA_IPTUN_LOCAL */
1669                 nla_total_size(sizeof(struct in6_addr)) +
1670                 /* IFLA_IPTUN_REMOTE */
1671                 nla_total_size(sizeof(struct in6_addr)) +
1672                 /* IFLA_IPTUN_TTL */
1673                 nla_total_size(1) +
1674                 /* IFLA_IPTUN_ENCAP_LIMIT */
1675                 nla_total_size(1) +
1676                 /* IFLA_IPTUN_FLOWINFO */
1677                 nla_total_size(4) +
1678                 /* IFLA_IPTUN_FLAGS */
1679                 nla_total_size(4) +
1680                 /* IFLA_IPTUN_PROTO */
1681                 nla_total_size(1) +
1682                 0;
1683 }
1684
1685 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1686 {
1687         struct ip6_tnl *tunnel = netdev_priv(dev);
1688         struct __ip6_tnl_parm *parm = &tunnel->parms;
1689
1690         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1691             nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1692                     &parm->laddr) ||
1693             nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1694                     &parm->raddr) ||
1695             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1696             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1697             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1698             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1699             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1700                 goto nla_put_failure;
1701         return 0;
1702
1703 nla_put_failure:
1704         return -EMSGSIZE;
1705 }
1706
1707 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1708         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1709         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
1710         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
1711         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1712         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
1713         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
1714         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
1715         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1716 };
1717
1718 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1719         .kind           = "ip6tnl",
1720         .maxtype        = IFLA_IPTUN_MAX,
1721         .policy         = ip6_tnl_policy,
1722         .priv_size      = sizeof(struct ip6_tnl),
1723         .setup          = ip6_tnl_dev_setup,
1724         .validate       = ip6_tnl_validate,
1725         .newlink        = ip6_tnl_newlink,
1726         .changelink     = ip6_tnl_changelink,
1727         .dellink        = ip6_tnl_dellink,
1728         .get_size       = ip6_tnl_get_size,
1729         .fill_info      = ip6_tnl_fill_info,
1730 };
1731
1732 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1733         .handler        = ip4ip6_rcv,
1734         .err_handler    = ip4ip6_err,
1735         .priority       =       1,
1736 };
1737
1738 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1739         .handler        = ip6ip6_rcv,
1740         .err_handler    = ip6ip6_err,
1741         .priority       =       1,
1742 };
1743
1744 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1745 {
1746         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1747         struct net_device *dev, *aux;
1748         int h;
1749         struct ip6_tnl *t;
1750         LIST_HEAD(list);
1751
1752         for_each_netdev_safe(net, dev, aux)
1753                 if (dev->rtnl_link_ops == &ip6_link_ops)
1754                         unregister_netdevice_queue(dev, &list);
1755
1756         for (h = 0; h < HASH_SIZE; h++) {
1757                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1758                 while (t != NULL) {
1759                         /* If dev is in the same netns, it has already
1760                          * been added to the list by the previous loop.
1761                          */
1762                         if (!net_eq(dev_net(t->dev), net))
1763                                 unregister_netdevice_queue(t->dev, &list);
1764                         t = rtnl_dereference(t->next);
1765                 }
1766         }
1767
1768         unregister_netdevice_many(&list);
1769 }
1770
1771 static int __net_init ip6_tnl_init_net(struct net *net)
1772 {
1773         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1774         struct ip6_tnl *t = NULL;
1775         int err;
1776
1777         ip6n->tnls[0] = ip6n->tnls_wc;
1778         ip6n->tnls[1] = ip6n->tnls_r_l;
1779
1780         err = -ENOMEM;
1781         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1782                                       ip6_tnl_dev_setup);
1783
1784         if (!ip6n->fb_tnl_dev)
1785                 goto err_alloc_dev;
1786         dev_net_set(ip6n->fb_tnl_dev, net);
1787         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1788         /* FB netdevice is special: we have one, and only one per netns.
1789          * Allowing to move it to another netns is clearly unsafe.
1790          */
1791         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1792
1793         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1794         if (err < 0)
1795                 goto err_register;
1796
1797         err = register_netdev(ip6n->fb_tnl_dev);
1798         if (err < 0)
1799                 goto err_register;
1800
1801         t = netdev_priv(ip6n->fb_tnl_dev);
1802
1803         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1804         return 0;
1805
1806 err_register:
1807         ip6_dev_free(ip6n->fb_tnl_dev);
1808 err_alloc_dev:
1809         return err;
1810 }
1811
1812 static void __net_exit ip6_tnl_exit_net(struct net *net)
1813 {
1814         rtnl_lock();
1815         ip6_tnl_destroy_tunnels(net);
1816         rtnl_unlock();
1817 }
1818
1819 static struct pernet_operations ip6_tnl_net_ops = {
1820         .init = ip6_tnl_init_net,
1821         .exit = ip6_tnl_exit_net,
1822         .id   = &ip6_tnl_net_id,
1823         .size = sizeof(struct ip6_tnl_net),
1824 };
1825
1826 /**
1827  * ip6_tunnel_init - register protocol and reserve needed resources
1828  *
1829  * Return: 0 on success
1830  **/
1831
1832 static int __init ip6_tunnel_init(void)
1833 {
1834         int  err;
1835
1836         err = register_pernet_device(&ip6_tnl_net_ops);
1837         if (err < 0)
1838                 goto out_pernet;
1839
1840         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1841         if (err < 0) {
1842                 pr_err("%s: can't register ip4ip6\n", __func__);
1843                 goto out_ip4ip6;
1844         }
1845
1846         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1847         if (err < 0) {
1848                 pr_err("%s: can't register ip6ip6\n", __func__);
1849                 goto out_ip6ip6;
1850         }
1851         err = rtnl_link_register(&ip6_link_ops);
1852         if (err < 0)
1853                 goto rtnl_link_failed;
1854
1855         return 0;
1856
1857 rtnl_link_failed:
1858         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1859 out_ip6ip6:
1860         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1861 out_ip4ip6:
1862         unregister_pernet_device(&ip6_tnl_net_ops);
1863 out_pernet:
1864         return err;
1865 }
1866
1867 /**
1868  * ip6_tunnel_cleanup - free resources and unregister protocol
1869  **/
1870
1871 static void __exit ip6_tunnel_cleanup(void)
1872 {
1873         rtnl_link_unregister(&ip6_link_ops);
1874         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1875                 pr_info("%s: can't deregister ip4ip6\n", __func__);
1876
1877         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1878                 pr_info("%s: can't deregister ip6ip6\n", __func__);
1879
1880         unregister_pernet_device(&ip6_tnl_net_ops);
1881 }
1882
1883 module_init(ip6_tunnel_init);
1884 module_exit(ip6_tunnel_cleanup);