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_irq(&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_irq(&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, NET_NAME_UNKNOWN,
 319                            ip6_tnl_dev_setup);
 320         if (dev == NULL)
 321                 goto failed;
 322
 323         dev_net_set(dev, net);
 324
 325         t = netdev_priv(dev);
 326         t->parms = *p;
 327         t->net = dev_net(dev);
 328         err = ip6_tnl_create2(dev);
 329         if (err < 0)
 330                 goto failed_free;
 331
 332         return t;
 333
 334 failed_free:
 335         ip6_dev_free(dev);
 336 failed:
 337         return NULL;
 338 }
 339
 340 /**
 341  * ip6_tnl_locate - find or create tunnel matching given parameters
 342  *   @p: tunnel parameters
 343  *   @create: != 0 if allowed to create new tunnel if no match found
 344  *
 345  * Description:
 346  *   ip6_tnl_locate() first tries to locate an existing tunnel
 347  *   based on @parms. If this is unsuccessful, but @create is set a new
 348  *   tunnel device is created and registered for use.
 349  *
 350  * Return:
 351  *   matching tunnel or NULL
 352  **/
 353
 354 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 355                 struct __ip6_tnl_parm *p, int create)
 356 {
 357         const struct in6_addr *remote = &p->raddr;
 358         const struct in6_addr *local = &p->laddr;
 359         struct ip6_tnl __rcu **tp;
 360         struct ip6_tnl *t;
 361         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 362
 363         for (tp = ip6_tnl_bucket(ip6n, p);
 364              (t = rtnl_dereference(*tp)) != NULL;
 365              tp = &t->next) {
 366                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 367                     ipv6_addr_equal(remote, &t->parms.raddr))
 368                         return t;
 369         }
 370         if (!create)
 371                 return NULL;
 372         return ip6_tnl_create(net, p);
 373 }
 374
 375 /**
 376  * ip6_tnl_dev_uninit - tunnel device uninitializer
 377  *   @dev: the device to be destroyed
 378  *
 379  * Description:
 380  *   ip6_tnl_dev_uninit() removes tunnel from its list
 381  **/
 382
 383 static void
 384 ip6_tnl_dev_uninit(struct net_device *dev)
 385 {
 386         struct ip6_tnl *t = netdev_priv(dev);
 387         struct net *net = t->net;
 388         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 389
 390         if (dev == ip6n->fb_tnl_dev)
 391                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 392         else
 393                 ip6_tnl_unlink(ip6n, t);
 394         ip6_tnl_dst_reset(t);
 395         dev_put(dev);
 396 }
 397
 398 /**
 399  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 400  *   @skb: received socket buffer
 401  *
 402  * Return:
 403  *   0 if none was found,
 404  *   else index to encapsulation limit
 405  **/
 406
 407 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 408 {
 409         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
 410         __u8 nexthdr = ipv6h->nexthdr;
 411         __u16 off = sizeof (*ipv6h);
 412
 413         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 414                 __u16 optlen = 0;
 415                 struct ipv6_opt_hdr *hdr;
 416                 if (raw + off + sizeof (*hdr) > skb->data &&
 417                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 418                         break;
 419
 420                 hdr = (struct ipv6_opt_hdr *) (raw + off);
 421                 if (nexthdr == NEXTHDR_FRAGMENT) {
 422                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 423                         if (frag_hdr->frag_off)
 424                                 break;
 425                         optlen = 8;
 426                 } else if (nexthdr == NEXTHDR_AUTH) {
 427                         optlen = (hdr->hdrlen + 2) << 2;
 428                 } else {
 429                         optlen = ipv6_optlen(hdr);
 430                 }
 431                 if (nexthdr == NEXTHDR_DEST) {
 432                         __u16 i = off + 2;
 433                         while (1) {
 434                                 struct ipv6_tlv_tnl_enc_lim *tel;
 435
 436                                 /* No more room for encapsulation limit */
 437                                 if (i + sizeof (*tel) > off + optlen)
 438                                         break;
 439
 440                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 441                                 /* return index of option if found and valid */
 442                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 443                                     tel->length == 1)
 444                                         return i;
 445                                 /* else jump to next option */
 446                                 if (tel->type)
 447                                         i += tel->length + 2;
 448                                 else
 449                                         i++;
 450                         }
 451                 }
 452                 nexthdr = hdr->nexthdr;
 453                 off += optlen;
 454         }
 455         return 0;
 456 }
 457 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 458
 459 /**
 460  * ip6_tnl_err - tunnel error handler
 461  *
 462  * Description:
 463  *   ip6_tnl_err() should handle errors in the tunnel according
 464  *   to the specifications in RFC 2473.
 465  **/
 466
 467 static int
 468 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 469             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 470 {
 471         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
 472         struct ip6_tnl *t;
 473         int rel_msg = 0;
 474         u8 rel_type = ICMPV6_DEST_UNREACH;
 475         u8 rel_code = ICMPV6_ADDR_UNREACH;
 476         __u32 rel_info = 0;
 477         __u16 len;
 478         int err = -ENOENT;
 479
 480         /* If the packet doesn't contain the original IPv6 header we are
 481            in trouble since we might need the source address for further
 482            processing of the error. */
 483
 484         rcu_read_lock();
 485         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
 486                                         &ipv6h->saddr)) == NULL)
 487                 goto out;
 488
 489         if (t->parms.proto != ipproto && t->parms.proto != 0)
 490                 goto out;
 491
 492         err = 0;
 493
 494         switch (*type) {
 495                 __u32 teli;
 496                 struct ipv6_tlv_tnl_enc_lim *tel;
 497                 __u32 mtu;
 498         case ICMPV6_DEST_UNREACH:
 499                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 500                                      t->parms.name);
 501                 rel_msg = 1;
 502                 break;
 503         case ICMPV6_TIME_EXCEED:
 504                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 505                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 506                                              t->parms.name);
 507                         rel_msg = 1;
 508                 }
 509                 break;
 510         case ICMPV6_PARAMPROB:
 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_warn_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_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 524                                              t->parms.name);
 525                 }
 526                 break;
 527         case ICMPV6_PKT_TOOBIG:
 528                 mtu = *info - offset;
 529                 if (mtu < IPV6_MIN_MTU)
 530                         mtu = IPV6_MIN_MTU;
 531                 t->dev->mtu = mtu;
 532
 533                 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 534                         rel_type = ICMPV6_PKT_TOOBIG;
 535                         rel_code = 0;
 536                         rel_info = mtu;
 537                         rel_msg = 1;
 538                 }
 539                 break;
 540         }
 541
 542         *type = rel_type;
 543         *code = rel_code;
 544         *info = rel_info;
 545         *msg = rel_msg;
 546
 547 out:
 548         rcu_read_unlock();
 549         return err;
 550 }
 551
 552 static int
 553 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 554            u8 type, u8 code, int offset, __be32 info)
 555 {
 556         int rel_msg = 0;
 557         u8 rel_type = type;
 558         u8 rel_code = code;
 559         __u32 rel_info = ntohl(info);
 560         int err;
 561         struct sk_buff *skb2;
 562         const struct iphdr *eiph;
 563         struct rtable *rt;
 564         struct flowi4 fl4;
 565
 566         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 567                           &rel_msg, &rel_info, offset);
 568         if (err < 0)
 569                 return err;
 570
 571         if (rel_msg == 0)
 572                 return 0;
 573
 574         switch (rel_type) {
 575         case ICMPV6_DEST_UNREACH:
 576                 if (rel_code != ICMPV6_ADDR_UNREACH)
 577                         return 0;
 578                 rel_type = ICMP_DEST_UNREACH;
 579                 rel_code = ICMP_HOST_UNREACH;
 580                 break;
 581         case ICMPV6_PKT_TOOBIG:
 582                 if (rel_code != 0)
 583                         return 0;
 584                 rel_type = ICMP_DEST_UNREACH;
 585                 rel_code = ICMP_FRAG_NEEDED;
 586                 break;
 587         case NDISC_REDIRECT:
 588                 rel_type = ICMP_REDIRECT;
 589                 rel_code = ICMP_REDIR_HOST;
 590         default:
 591                 return 0;
 592         }
 593
 594         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 595                 return 0;
 596
 597         skb2 = skb_clone(skb, GFP_ATOMIC);
 598         if (!skb2)
 599                 return 0;
 600
 601         skb_dst_drop(skb2);
 602
 603         skb_pull(skb2, offset);
 604         skb_reset_network_header(skb2);
 605         eiph = ip_hdr(skb2);
 606
 607         /* Try to guess incoming interface */
 608         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 609                                    eiph->saddr, 0,
 610                                    0, 0,
 611                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 612         if (IS_ERR(rt))
 613                 goto out;
 614
 615         skb2->dev = rt->dst.dev;
 616
 617         /* route "incoming" packet */
 618         if (rt->rt_flags & RTCF_LOCAL) {
 619                 ip_rt_put(rt);
 620                 rt = NULL;
 621                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 622                                            eiph->daddr, eiph->saddr,
 623                                            0, 0,
 624                                            IPPROTO_IPIP,
 625                                            RT_TOS(eiph->tos), 0);
 626                 if (IS_ERR(rt) ||
 627                     rt->dst.dev->type != ARPHRD_TUNNEL) {
 628                         if (!IS_ERR(rt))
 629                                 ip_rt_put(rt);
 630                         goto out;
 631                 }
 632                 skb_dst_set(skb2, &rt->dst);
 633         } else {
 634                 ip_rt_put(rt);
 635                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 636                                    skb2->dev) ||
 637                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 638                         goto out;
 639         }
 640
 641         /* change mtu on this route */
 642         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 643                 if (rel_info > dst_mtu(skb_dst(skb2)))
 644                         goto out;
 645
 646                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
 647         }
 648         if (rel_type == ICMP_REDIRECT)
 649                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
 650
 651         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 652
 653 out:
 654         kfree_skb(skb2);
 655         return 0;
 656 }
 657
 658 static int
 659 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 660            u8 type, u8 code, int offset, __be32 info)
 661 {
 662         int rel_msg = 0;
 663         u8 rel_type = type;
 664         u8 rel_code = code;
 665         __u32 rel_info = ntohl(info);
 666         int err;
 667
 668         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 669                           &rel_msg, &rel_info, offset);
 670         if (err < 0)
 671                 return err;
 672
 673         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 674                 struct rt6_info *rt;
 675                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 676
 677                 if (!skb2)
 678                         return 0;
 679
 680                 skb_dst_drop(skb2);
 681                 skb_pull(skb2, offset);
 682                 skb_reset_network_header(skb2);
 683
 684                 /* Try to guess incoming interface */
 685                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 686                                 NULL, 0, 0);
 687
 688                 if (rt && rt->dst.dev)
 689                         skb2->dev = rt->dst.dev;
 690
 691                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 692
 693                 ip6_rt_put(rt);
 694
 695                 kfree_skb(skb2);
 696         }
 697
 698         return 0;
 699 }
 700
 701 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 702                                        const struct ipv6hdr *ipv6h,
 703                                        struct sk_buff *skb)
 704 {
 705         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 706
 707         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 708                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 709
 710         return IP6_ECN_decapsulate(ipv6h, skb);
 711 }
 712
 713 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 714                                        const struct ipv6hdr *ipv6h,
 715                                        struct sk_buff *skb)
 716 {
 717         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 718                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 719
 720         return IP6_ECN_decapsulate(ipv6h, skb);
 721 }
 722
 723 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 724                              const struct in6_addr *laddr,
 725                              const struct in6_addr *raddr)
 726 {
 727         struct __ip6_tnl_parm *p = &t->parms;
 728         int ltype = ipv6_addr_type(laddr);
 729         int rtype = ipv6_addr_type(raddr);
 730         __u32 flags = 0;
 731
 732         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 733                 flags = IP6_TNL_F_CAP_PER_PACKET;
 734         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 735                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 736                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 737                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 738                 if (ltype&IPV6_ADDR_UNICAST)
 739                         flags |= IP6_TNL_F_CAP_XMIT;
 740                 if (rtype&IPV6_ADDR_UNICAST)
 741                         flags |= IP6_TNL_F_CAP_RCV;
 742         }
 743         return flags;
 744 }
 745 EXPORT_SYMBOL(ip6_tnl_get_cap);
 746
 747 /* called with rcu_read_lock() */
 748 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 749                                   const struct in6_addr *laddr,
 750                                   const struct in6_addr *raddr)
 751 {
 752         struct __ip6_tnl_parm *p = &t->parms;
 753         int ret = 0;
 754         struct net *net = t->net;
 755
 756         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 757             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 758              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 759                 struct net_device *ldev = NULL;
 760
 761                 if (p->link)
 762                         ldev = dev_get_by_index_rcu(net, p->link);
 763
 764                 if ((ipv6_addr_is_multicast(laddr) ||
 765                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
 766                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
 767                         ret = 1;
 768         }
 769         return ret;
 770 }
 771 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 772
 773 /**
 774  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 775  *   @skb: received socket buffer
 776  *   @protocol: ethernet protocol ID
 777  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 778  *
 779  * Return: 0
 780  **/
 781
 782 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 783                        __u8 ipproto,
 784                        int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 785                                                    const struct ipv6hdr *ipv6h,
 786                                                    struct sk_buff *skb))
 787 {
 788         struct ip6_tnl *t;
 789         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 790         int err;
 791
 792         rcu_read_lock();
 793
 794         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
 795                                         &ipv6h->daddr)) != NULL) {
 796                 struct pcpu_sw_netstats *tstats;
 797
 798                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
 799                         rcu_read_unlock();
 800                         goto discard;
 801                 }
 802
 803                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 804                         rcu_read_unlock();
 805                         goto discard;
 806                 }
 807
 808                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 809                         t->dev->stats.rx_dropped++;
 810                         rcu_read_unlock();
 811                         goto discard;
 812                 }
 813                 skb->mac_header = skb->network_header;
 814                 skb_reset_network_header(skb);
 815                 skb->protocol = htons(protocol);
 816                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 817
 818                 __skb_tunnel_rx(skb, t->dev, t->net);
 819
 820                 err = dscp_ecn_decapsulate(t, ipv6h, skb);
 821                 if (unlikely(err)) {
 822                         if (log_ecn_error)
 823                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 824                                                      &ipv6h->saddr,
 825                                                      ipv6_get_dsfield(ipv6h));
 826                         if (err > 1) {
 827                                 ++t->dev->stats.rx_frame_errors;
 828                                 ++t->dev->stats.rx_errors;
 829                                 rcu_read_unlock();
 830                                 goto discard;
 831                         }
 832                 }
 833
 834                 tstats = this_cpu_ptr(t->dev->tstats);
 835                 u64_stats_update_begin(&tstats->syncp);
 836                 tstats->rx_packets++;
 837                 tstats->rx_bytes += skb->len;
 838                 u64_stats_update_end(&tstats->syncp);
 839
 840                 netif_rx(skb);
 841
 842                 rcu_read_unlock();
 843                 return 0;
 844         }
 845         rcu_read_unlock();
 846         return 1;
 847
 848 discard:
 849         kfree_skb(skb);
 850         return 0;
 851 }
 852
 853 static int ip4ip6_rcv(struct sk_buff *skb)
 854 {
 855         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 856                            ip4ip6_dscp_ecn_decapsulate);
 857 }
 858
 859 static int ip6ip6_rcv(struct sk_buff *skb)
 860 {
 861         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 862                            ip6ip6_dscp_ecn_decapsulate);
 863 }
 864
 865 struct ipv6_tel_txoption {
 866         struct ipv6_txoptions ops;
 867         __u8 dst_opt[8];
 868 };
 869
 870 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 871 {
 872         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 873
 874         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 875         opt->dst_opt[3] = 1;
 876         opt->dst_opt[4] = encap_limit;
 877         opt->dst_opt[5] = IPV6_TLV_PADN;
 878         opt->dst_opt[6] = 1;
 879
 880         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 881         opt->ops.opt_nflen = 8;
 882 }
 883
 884 /**
 885  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 886  *   @t: the outgoing tunnel device
 887  *   @hdr: IPv6 header from the incoming packet
 888  *
 889  * Description:
 890  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 891  *   doesn't match source of incoming packet.
 892  *
 893  * Return:
 894  *   1 if conflict,
 895  *   0 else
 896  **/
 897
 898 static inline bool
 899 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 900 {
 901         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 902 }
 903
 904 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 905 {
 906         struct __ip6_tnl_parm *p = &t->parms;
 907         int ret = 0;
 908         struct net *net = t->net;
 909
 910         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 911                 struct net_device *ldev = NULL;
 912
 913                 rcu_read_lock();
 914                 if (p->link)
 915                         ldev = dev_get_by_index_rcu(net, p->link);
 916
 917                 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
 918                         pr_warn("%s xmit: Local address not yet configured!\n",
 919                                 p->name);
 920                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
 921                          unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
 922                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
 923                                 p->name);
 924                 else
 925                         ret = 1;
 926                 rcu_read_unlock();
 927         }
 928         return ret;
 929 }
 930 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
 931
 932 /**
 933  * ip6_tnl_xmit2 - encapsulate packet and send
 934  *   @skb: the outgoing socket buffer
 935  *   @dev: the outgoing tunnel device
 936  *   @dsfield: dscp code for outer header
 937  *   @fl: flow of tunneled packet
 938  *   @encap_limit: encapsulation limit
 939  *   @pmtu: Path MTU is stored if packet is too big
 940  *
 941  * Description:
 942  *   Build new header and do some sanity checks on the packet before sending
 943  *   it.
 944  *
 945  * Return:
 946  *   0 on success
 947  *   -1 fail
 948  *   %-EMSGSIZE message too big. return mtu in this case.
 949  **/
 950
 951 static int ip6_tnl_xmit2(struct sk_buff *skb,
 952                          struct net_device *dev,
 953                          __u8 dsfield,
 954                          struct flowi6 *fl6,
 955                          int encap_limit,
 956                          __u32 *pmtu)
 957 {
 958         struct ip6_tnl *t = netdev_priv(dev);
 959         struct net *net = t->net;
 960         struct net_device_stats *stats = &t->dev->stats;
 961         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 962         struct ipv6_tel_txoption opt;
 963         struct dst_entry *dst = NULL, *ndst = NULL;
 964         struct net_device *tdev;
 965         int mtu;
 966         unsigned int max_headroom = sizeof(struct ipv6hdr);
 967         u8 proto;
 968         int err = -1;
 969
 970         if (!fl6->flowi6_mark)
 971                 dst = ip6_tnl_dst_check(t);
 972         if (!dst) {
 973                 ndst = ip6_route_output(net, NULL, fl6);
 974
 975                 if (ndst->error)
 976                         goto tx_err_link_failure;
 977                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 978                 if (IS_ERR(ndst)) {
 979                         err = PTR_ERR(ndst);
 980                         ndst = NULL;
 981                         goto tx_err_link_failure;
 982                 }
 983                 dst = ndst;
 984         }
 985
 986         tdev = dst->dev;
 987
 988         if (tdev == dev) {
 989                 stats->collisions++;
 990                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 991                                      t->parms.name);
 992                 goto tx_err_dst_release;
 993         }
 994         mtu = dst_mtu(dst) - sizeof (*ipv6h);
 995         if (encap_limit >= 0) {
 996                 max_headroom += 8;
 997                 mtu -= 8;
 998         }
 999         if (mtu < IPV6_MIN_MTU)
1000                 mtu = IPV6_MIN_MTU;
1001         if (skb_dst(skb))
1002                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1003         if (skb->len > mtu) {
1004                 *pmtu = mtu;
1005                 err = -EMSGSIZE;
1006                 goto tx_err_dst_release;
1007         }
1008
1009         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1010
1011         /*
1012          * Okay, now see if we can stuff it in the buffer as-is.
1013          */
1014         max_headroom += LL_RESERVED_SPACE(tdev);
1015
1016         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1017             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1018                 struct sk_buff *new_skb;
1019
1020                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1021                         goto tx_err_dst_release;
1022
1023                 if (skb->sk)
1024                         skb_set_owner_w(new_skb, skb->sk);
1025                 consume_skb(skb);
1026                 skb = new_skb;
1027         }
1028         if (fl6->flowi6_mark) {
1029                 skb_dst_set(skb, dst);
1030                 ndst = NULL;
1031         } else {
1032                 skb_dst_set_noref(skb, dst);
1033         }
1034         skb->transport_header = skb->network_header;
1035
1036         proto = fl6->flowi6_proto;
1037         if (encap_limit >= 0) {
1038                 init_tel_txopt(&opt, encap_limit);
1039                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1040         }
1041
1042         if (likely(!skb->encapsulation)) {
1043                 skb_reset_inner_headers(skb);
1044                 skb->encapsulation = 1;
1045         }
1046
1047         skb_push(skb, sizeof(struct ipv6hdr));
1048         skb_reset_network_header(skb);
1049         ipv6h = ipv6_hdr(skb);
1050         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1051                      ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
1052         ipv6h->hop_limit = t->parms.hop_limit;
1053         ipv6h->nexthdr = proto;
1054         ipv6h->saddr = fl6->saddr;
1055         ipv6h->daddr = fl6->daddr;
1056         ip6tunnel_xmit(skb, dev);
1057         if (ndst)
1058                 ip6_tnl_dst_store(t, ndst);
1059         return 0;
1060 tx_err_link_failure:
1061         stats->tx_carrier_errors++;
1062         dst_link_failure(skb);
1063 tx_err_dst_release:
1064         dst_release(ndst);
1065         return err;
1066 }
1067
1068 static inline int
1069 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1070 {
1071         struct ip6_tnl *t = netdev_priv(dev);
1072         const struct iphdr  *iph = ip_hdr(skb);
1073         int encap_limit = -1;
1074         struct flowi6 fl6;
1075         __u8 dsfield;
1076         __u32 mtu;
1077         int err;
1078
1079         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1080             !ip6_tnl_xmit_ctl(t))
1081                 return -1;
1082
1083         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1084                 encap_limit = t->parms.encap_limit;
1085
1086         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1087         fl6.flowi6_proto = IPPROTO_IPIP;
1088
1089         dsfield = ipv4_get_dsfield(iph);
1090
1091         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1092                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1093                                           & IPV6_TCLASS_MASK;
1094         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1095                 fl6.flowi6_mark = skb->mark;
1096
1097         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1098         if (err != 0) {
1099                 /* XXX: send ICMP error even if DF is not set. */
1100                 if (err == -EMSGSIZE)
1101                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1102                                   htonl(mtu));
1103                 return -1;
1104         }
1105
1106         return 0;
1107 }
1108
1109 static inline int
1110 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1111 {
1112         struct ip6_tnl *t = netdev_priv(dev);
1113         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1114         int encap_limit = -1;
1115         __u16 offset;
1116         struct flowi6 fl6;
1117         __u8 dsfield;
1118         __u32 mtu;
1119         int err;
1120
1121         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1122             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1123                 return -1;
1124
1125         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1126         if (offset > 0) {
1127                 struct ipv6_tlv_tnl_enc_lim *tel;
1128                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1129                 if (tel->encap_limit == 0) {
1130                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1131                                     ICMPV6_HDR_FIELD, offset + 2);
1132                         return -1;
1133                 }
1134                 encap_limit = tel->encap_limit - 1;
1135         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1136                 encap_limit = t->parms.encap_limit;
1137
1138         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1139         fl6.flowi6_proto = IPPROTO_IPV6;
1140
1141         dsfield = ipv6_get_dsfield(ipv6h);
1142         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1143                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1144         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1145                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1146         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1147                 fl6.flowi6_mark = skb->mark;
1148
1149         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1150         if (err != 0) {
1151                 if (err == -EMSGSIZE)
1152                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1153                 return -1;
1154         }
1155
1156         return 0;
1157 }
1158
1159 static netdev_tx_t
1160 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1161 {
1162         struct ip6_tnl *t = netdev_priv(dev);
1163         struct net_device_stats *stats = &t->dev->stats;
1164         int ret;
1165
1166         switch (skb->protocol) {
1167         case htons(ETH_P_IP):
1168                 ret = ip4ip6_tnl_xmit(skb, dev);
1169                 break;
1170         case htons(ETH_P_IPV6):
1171                 ret = ip6ip6_tnl_xmit(skb, dev);
1172                 break;
1173         default:
1174                 goto tx_err;
1175         }
1176
1177         if (ret < 0)
1178                 goto tx_err;
1179
1180         return NETDEV_TX_OK;
1181
1182 tx_err:
1183         stats->tx_errors++;
1184         stats->tx_dropped++;
1185         kfree_skb(skb);
1186         return NETDEV_TX_OK;
1187 }
1188
1189 static void ip6_tnl_link_config(struct ip6_tnl *t)
1190 {
1191         struct net_device *dev = t->dev;
1192         struct __ip6_tnl_parm *p = &t->parms;
1193         struct flowi6 *fl6 = &t->fl.u.ip6;
1194
1195         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1196         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1197
1198         /* Set up flowi template */
1199         fl6->saddr = p->laddr;
1200         fl6->daddr = p->raddr;
1201         fl6->flowi6_oif = p->link;
1202         fl6->flowlabel = 0;
1203
1204         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1205                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1206         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1207                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1208
1209         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1210         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1211
1212         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1213                 dev->flags |= IFF_POINTOPOINT;
1214         else
1215                 dev->flags &= ~IFF_POINTOPOINT;
1216
1217         dev->iflink = p->link;
1218
1219         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1220                 int strict = (ipv6_addr_type(&p->raddr) &
1221                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1222
1223                 struct rt6_info *rt = rt6_lookup(t->net,
1224                                                  &p->raddr, &p->laddr,
1225                                                  p->link, strict);
1226
1227                 if (rt == NULL)
1228                         return;
1229
1230                 if (rt->dst.dev) {
1231                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1232                                 sizeof (struct ipv6hdr);
1233
1234                         dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1235                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1236                                 dev->mtu-=8;
1237
1238                         if (dev->mtu < IPV6_MIN_MTU)
1239                                 dev->mtu = IPV6_MIN_MTU;
1240                 }
1241                 ip6_rt_put(rt);
1242         }
1243 }
1244
1245 /**
1246  * ip6_tnl_change - update the tunnel parameters
1247  *   @t: tunnel to be changed
1248  *   @p: tunnel configuration parameters
1249  *
1250  * Description:
1251  *   ip6_tnl_change() updates the tunnel parameters
1252  **/
1253
1254 static int
1255 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1256 {
1257         t->parms.laddr = p->laddr;
1258         t->parms.raddr = p->raddr;
1259         t->parms.flags = p->flags;
1260         t->parms.hop_limit = p->hop_limit;
1261         t->parms.encap_limit = p->encap_limit;
1262         t->parms.flowinfo = p->flowinfo;
1263         t->parms.link = p->link;
1264         t->parms.proto = p->proto;
1265         ip6_tnl_dst_reset(t);
1266         ip6_tnl_link_config(t);
1267         return 0;
1268 }
1269
1270 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1271 {
1272         struct net *net = t->net;
1273         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1274         int err;
1275
1276         ip6_tnl_unlink(ip6n, t);
1277         synchronize_net();
1278         err = ip6_tnl_change(t, p);
1279         ip6_tnl_link(ip6n, t);
1280         netdev_state_change(t->dev);
1281         return err;
1282 }
1283
1284 static void
1285 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1286 {
1287         p->laddr = u->laddr;
1288         p->raddr = u->raddr;
1289         p->flags = u->flags;
1290         p->hop_limit = u->hop_limit;
1291         p->encap_limit = u->encap_limit;
1292         p->flowinfo = u->flowinfo;
1293         p->link = u->link;
1294         p->proto = u->proto;
1295         memcpy(p->name, u->name, sizeof(u->name));
1296 }
1297
1298 static void
1299 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1300 {
1301         u->laddr = p->laddr;
1302         u->raddr = p->raddr;
1303         u->flags = p->flags;
1304         u->hop_limit = p->hop_limit;
1305         u->encap_limit = p->encap_limit;
1306         u->flowinfo = p->flowinfo;
1307         u->link = p->link;
1308         u->proto = p->proto;
1309         memcpy(u->name, p->name, sizeof(u->name));
1310 }
1311
1312 /**
1313  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1314  *   @dev: virtual device associated with tunnel
1315  *   @ifr: parameters passed from userspace
1316  *   @cmd: command to be performed
1317  *
1318  * Description:
1319  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1320  *   from userspace.
1321  *
1322  *   The possible commands are the following:
1323  *     %SIOCGETTUNNEL: get tunnel parameters for device
1324  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1325  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1326  *     %SIOCDELTUNNEL: delete tunnel
1327  *
1328  *   The fallback device "ip6tnl0", created during module
1329  *   initialization, can be used for creating other tunnel devices.
1330  *
1331  * Return:
1332  *   0 on success,
1333  *   %-EFAULT if unable to copy data to or from userspace,
1334  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1335  *   %-EINVAL if passed tunnel parameters are invalid,
1336  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1337  *   %-ENODEV if attempting to change or delete a nonexisting device
1338  **/
1339
1340 static int
1341 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1342 {
1343         int err = 0;
1344         struct ip6_tnl_parm p;
1345         struct __ip6_tnl_parm p1;
1346         struct ip6_tnl *t = netdev_priv(dev);
1347         struct net *net = t->net;
1348         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1349
1350         switch (cmd) {
1351         case SIOCGETTUNNEL:
1352                 if (dev == ip6n->fb_tnl_dev) {
1353                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1354                                 err = -EFAULT;
1355                                 break;
1356                         }
1357                         ip6_tnl_parm_from_user(&p1, &p);
1358                         t = ip6_tnl_locate(net, &p1, 0);
1359                         if (t == NULL)
1360                                 t = netdev_priv(dev);
1361                 } else {
1362                         memset(&p, 0, sizeof(p));
1363                 }
1364                 ip6_tnl_parm_to_user(&p, &t->parms);
1365                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1366                         err = -EFAULT;
1367                 }
1368                 break;
1369         case SIOCADDTUNNEL:
1370         case SIOCCHGTUNNEL:
1371                 err = -EPERM;
1372                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1373                         break;
1374                 err = -EFAULT;
1375                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1376                         break;
1377                 err = -EINVAL;
1378                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1379                     p.proto != 0)
1380                         break;
1381                 ip6_tnl_parm_from_user(&p1, &p);
1382                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1383                 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1384                         if (t != NULL) {
1385                                 if (t->dev != dev) {
1386                                         err = -EEXIST;
1387                                         break;
1388                                 }
1389                         } else
1390                                 t = netdev_priv(dev);
1391
1392                         err = ip6_tnl_update(t, &p1);
1393                 }
1394                 if (t) {
1395                         err = 0;
1396                         ip6_tnl_parm_to_user(&p, &t->parms);
1397                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1398                                 err = -EFAULT;
1399
1400                 } else
1401                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1402                 break;
1403         case SIOCDELTUNNEL:
1404                 err = -EPERM;
1405                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1406                         break;
1407
1408                 if (dev == ip6n->fb_tnl_dev) {
1409                         err = -EFAULT;
1410                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1411                                 break;
1412                         err = -ENOENT;
1413                         ip6_tnl_parm_from_user(&p1, &p);
1414                         t = ip6_tnl_locate(net, &p1, 0);
1415                         if (t == NULL)
1416                                 break;
1417                         err = -EPERM;
1418                         if (t->dev == ip6n->fb_tnl_dev)
1419                                 break;
1420                         dev = t->dev;
1421                 }
1422                 err = 0;
1423                 unregister_netdevice(dev);
1424                 break;
1425         default:
1426                 err = -EINVAL;
1427         }
1428         return err;
1429 }
1430
1431 /**
1432  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1433  *   @dev: virtual device associated with tunnel
1434  *   @new_mtu: the new mtu
1435  *
1436  * Return:
1437  *   0 on success,
1438  *   %-EINVAL if mtu too small
1439  **/
1440
1441 static int
1442 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1443 {
1444         struct ip6_tnl *tnl = netdev_priv(dev);
1445
1446         if (tnl->parms.proto == IPPROTO_IPIP) {
1447                 if (new_mtu < 68)
1448                         return -EINVAL;
1449         } else {
1450                 if (new_mtu < IPV6_MIN_MTU)
1451                         return -EINVAL;
1452         }
1453         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1454                 return -EINVAL;
1455         dev->mtu = new_mtu;
1456         return 0;
1457 }
1458
1459
1460 static const struct net_device_ops ip6_tnl_netdev_ops = {
1461         .ndo_uninit     = ip6_tnl_dev_uninit,
1462         .ndo_start_xmit = ip6_tnl_xmit,
1463         .ndo_do_ioctl   = ip6_tnl_ioctl,
1464         .ndo_change_mtu = ip6_tnl_change_mtu,
1465         .ndo_get_stats  = ip6_get_stats,
1466 };
1467
1468
1469 /**
1470  * ip6_tnl_dev_setup - setup virtual tunnel device
1471  *   @dev: virtual device associated with tunnel
1472  *
1473  * Description:
1474  *   Initialize function pointers and device parameters
1475  **/
1476
1477 static void ip6_tnl_dev_setup(struct net_device *dev)
1478 {
1479         struct ip6_tnl *t;
1480
1481         dev->netdev_ops = &ip6_tnl_netdev_ops;
1482         dev->destructor = ip6_dev_free;
1483
1484         dev->type = ARPHRD_TUNNEL6;
1485         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1486         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1487         t = netdev_priv(dev);
1488         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1489                 dev->mtu-=8;
1490         dev->flags |= IFF_NOARP;
1491         dev->addr_len = sizeof(struct in6_addr);
1492         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1493         /* This perm addr will be used as interface identifier by IPv6 */
1494         dev->addr_assign_type = NET_ADDR_RANDOM;
1495         eth_random_addr(dev->perm_addr);
1496 }
1497
1498
1499 /**
1500  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1501  *   @dev: virtual device associated with tunnel
1502  **/
1503
1504 static inline int
1505 ip6_tnl_dev_init_gen(struct net_device *dev)
1506 {
1507         struct ip6_tnl *t = netdev_priv(dev);
1508
1509         t->dev = dev;
1510         t->net = dev_net(dev);
1511         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1512         if (!dev->tstats)
1513                 return -ENOMEM;
1514         return 0;
1515 }
1516
1517 /**
1518  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1519  *   @dev: virtual device associated with tunnel
1520  **/
1521
1522 static int ip6_tnl_dev_init(struct net_device *dev)
1523 {
1524         struct ip6_tnl *t = netdev_priv(dev);
1525         int err = ip6_tnl_dev_init_gen(dev);
1526
1527         if (err)
1528                 return err;
1529         ip6_tnl_link_config(t);
1530         return 0;
1531 }
1532
1533 /**
1534  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1535  *   @dev: fallback device
1536  *
1537  * Return: 0
1538  **/
1539
1540 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1541 {
1542         struct ip6_tnl *t = netdev_priv(dev);
1543         struct net *net = dev_net(dev);
1544         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1545         int err = ip6_tnl_dev_init_gen(dev);
1546
1547         if (err)
1548                 return err;
1549
1550         t->parms.proto = IPPROTO_IPV6;
1551         dev_hold(dev);
1552
1553         ip6_tnl_link_config(t);
1554
1555         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1556         return 0;
1557 }
1558
1559 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1560 {
1561         u8 proto;
1562
1563         if (!data || !data[IFLA_IPTUN_PROTO])
1564                 return 0;
1565
1566         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1567         if (proto != IPPROTO_IPV6 &&
1568             proto != IPPROTO_IPIP &&
1569             proto != 0)
1570                 return -EINVAL;
1571
1572         return 0;
1573 }
1574
1575 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1576                                   struct __ip6_tnl_parm *parms)
1577 {
1578         memset(parms, 0, sizeof(*parms));
1579
1580         if (!data)
1581                 return;
1582
1583         if (data[IFLA_IPTUN_LINK])
1584                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1585
1586         if (data[IFLA_IPTUN_LOCAL])
1587                 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1588                            sizeof(struct in6_addr));
1589
1590         if (data[IFLA_IPTUN_REMOTE])
1591                 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1592                            sizeof(struct in6_addr));
1593
1594         if (data[IFLA_IPTUN_TTL])
1595                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1596
1597         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1598                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1599
1600         if (data[IFLA_IPTUN_FLOWINFO])
1601                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1602
1603         if (data[IFLA_IPTUN_FLAGS])
1604                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1605
1606         if (data[IFLA_IPTUN_PROTO])
1607                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1608 }
1609
1610 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1611                            struct nlattr *tb[], struct nlattr *data[])
1612 {
1613         struct net *net = dev_net(dev);
1614         struct ip6_tnl *nt;
1615
1616         nt = netdev_priv(dev);
1617         ip6_tnl_netlink_parms(data, &nt->parms);
1618
1619         if (ip6_tnl_locate(net, &nt->parms, 0))
1620                 return -EEXIST;
1621
1622         return ip6_tnl_create2(dev);
1623 }
1624
1625 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1626                               struct nlattr *data[])
1627 {
1628         struct ip6_tnl *t = netdev_priv(dev);
1629         struct __ip6_tnl_parm p;
1630         struct net *net = t->net;
1631         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1632
1633         if (dev == ip6n->fb_tnl_dev)
1634                 return -EINVAL;
1635
1636         ip6_tnl_netlink_parms(data, &p);
1637
1638         t = ip6_tnl_locate(net, &p, 0);
1639
1640         if (t) {
1641                 if (t->dev != dev)
1642                         return -EEXIST;
1643         } else
1644                 t = netdev_priv(dev);
1645
1646         return ip6_tnl_update(t, &p);
1647 }
1648
1649 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1650 {
1651         struct net *net = dev_net(dev);
1652         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1653
1654         if (dev != ip6n->fb_tnl_dev)
1655                 unregister_netdevice_queue(dev, head);
1656 }
1657
1658 static size_t ip6_tnl_get_size(const struct net_device *dev)
1659 {
1660         return
1661                 /* IFLA_IPTUN_LINK */
1662                 nla_total_size(4) +
1663                 /* IFLA_IPTUN_LOCAL */
1664                 nla_total_size(sizeof(struct in6_addr)) +
1665                 /* IFLA_IPTUN_REMOTE */
1666                 nla_total_size(sizeof(struct in6_addr)) +
1667                 /* IFLA_IPTUN_TTL */
1668                 nla_total_size(1) +
1669                 /* IFLA_IPTUN_ENCAP_LIMIT */
1670                 nla_total_size(1) +
1671                 /* IFLA_IPTUN_FLOWINFO */
1672                 nla_total_size(4) +
1673                 /* IFLA_IPTUN_FLAGS */
1674                 nla_total_size(4) +
1675                 /* IFLA_IPTUN_PROTO */
1676                 nla_total_size(1) +
1677                 0;
1678 }
1679
1680 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1681 {
1682         struct ip6_tnl *tunnel = netdev_priv(dev);
1683         struct __ip6_tnl_parm *parm = &tunnel->parms;
1684
1685         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1686             nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1687                     &parm->laddr) ||
1688             nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1689                     &parm->raddr) ||
1690             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1691             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1692             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1693             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1694             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1695                 goto nla_put_failure;
1696         return 0;
1697
1698 nla_put_failure:
1699         return -EMSGSIZE;
1700 }
1701
1702 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1703         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1704         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
1705         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
1706         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1707         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
1708         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
1709         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
1710         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1711 };
1712
1713 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1714         .kind           = "ip6tnl",
1715         .maxtype        = IFLA_IPTUN_MAX,
1716         .policy         = ip6_tnl_policy,
1717         .priv_size      = sizeof(struct ip6_tnl),
1718         .setup          = ip6_tnl_dev_setup,
1719         .validate       = ip6_tnl_validate,
1720         .newlink        = ip6_tnl_newlink,
1721         .changelink     = ip6_tnl_changelink,
1722         .dellink        = ip6_tnl_dellink,
1723         .get_size       = ip6_tnl_get_size,
1724         .fill_info      = ip6_tnl_fill_info,
1725 };
1726
1727 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1728         .handler        = ip4ip6_rcv,
1729         .err_handler    = ip4ip6_err,
1730         .priority       =       1,
1731 };
1732
1733 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1734         .handler        = ip6ip6_rcv,
1735         .err_handler    = ip6ip6_err,
1736         .priority       =       1,
1737 };
1738
1739 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1740 {
1741         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1742         struct net_device *dev, *aux;
1743         int h;
1744         struct ip6_tnl *t;
1745         LIST_HEAD(list);
1746
1747         for_each_netdev_safe(net, dev, aux)
1748                 if (dev->rtnl_link_ops == &ip6_link_ops)
1749                         unregister_netdevice_queue(dev, &list);
1750
1751         for (h = 0; h < HASH_SIZE; h++) {
1752                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1753                 while (t != NULL) {
1754                         /* If dev is in the same netns, it has already
1755                          * been added to the list by the previous loop.
1756                          */
1757                         if (!net_eq(dev_net(t->dev), net))
1758                                 unregister_netdevice_queue(t->dev, &list);
1759                         t = rtnl_dereference(t->next);
1760                 }
1761         }
1762
1763         unregister_netdevice_many(&list);
1764 }
1765
1766 static int __net_init ip6_tnl_init_net(struct net *net)
1767 {
1768         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1769         struct ip6_tnl *t = NULL;
1770         int err;
1771
1772         ip6n->tnls[0] = ip6n->tnls_wc;
1773         ip6n->tnls[1] = ip6n->tnls_r_l;
1774
1775         err = -ENOMEM;
1776         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1777                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
1778
1779         if (!ip6n->fb_tnl_dev)
1780                 goto err_alloc_dev;
1781         dev_net_set(ip6n->fb_tnl_dev, net);
1782         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1783         /* FB netdevice is special: we have one, and only one per netns.
1784          * Allowing to move it to another netns is clearly unsafe.
1785          */
1786         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1787
1788         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1789         if (err < 0)
1790                 goto err_register;
1791
1792         err = register_netdev(ip6n->fb_tnl_dev);
1793         if (err < 0)
1794                 goto err_register;
1795
1796         t = netdev_priv(ip6n->fb_tnl_dev);
1797
1798         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1799         return 0;
1800
1801 err_register:
1802         ip6_dev_free(ip6n->fb_tnl_dev);
1803 err_alloc_dev:
1804         return err;
1805 }
1806
1807 static void __net_exit ip6_tnl_exit_net(struct net *net)
1808 {
1809         rtnl_lock();
1810         ip6_tnl_destroy_tunnels(net);
1811         rtnl_unlock();
1812 }
1813
1814 static struct pernet_operations ip6_tnl_net_ops = {
1815         .init = ip6_tnl_init_net,
1816         .exit = ip6_tnl_exit_net,
1817         .id   = &ip6_tnl_net_id,
1818         .size = sizeof(struct ip6_tnl_net),
1819 };
1820
1821 /**
1822  * ip6_tunnel_init - register protocol and reserve needed resources
1823  *
1824  * Return: 0 on success
1825  **/
1826
1827 static int __init ip6_tunnel_init(void)
1828 {
1829         int  err;
1830
1831         err = register_pernet_device(&ip6_tnl_net_ops);
1832         if (err < 0)
1833                 goto out_pernet;
1834
1835         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1836         if (err < 0) {
1837                 pr_err("%s: can't register ip4ip6\n", __func__);
1838                 goto out_ip4ip6;
1839         }
1840
1841         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1842         if (err < 0) {
1843                 pr_err("%s: can't register ip6ip6\n", __func__);
1844                 goto out_ip6ip6;
1845         }
1846         err = rtnl_link_register(&ip6_link_ops);
1847         if (err < 0)
1848                 goto rtnl_link_failed;
1849
1850         return 0;
1851
1852 rtnl_link_failed:
1853         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1854 out_ip6ip6:
1855         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1856 out_ip4ip6:
1857         unregister_pernet_device(&ip6_tnl_net_ops);
1858 out_pernet:
1859         return err;
1860 }
1861
1862 /**
1863  * ip6_tunnel_cleanup - free resources and unregister protocol
1864  **/
1865
1866 static void __exit ip6_tunnel_cleanup(void)
1867 {
1868         rtnl_link_unregister(&ip6_link_ops);
1869         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1870                 pr_info("%s: can't deregister ip4ip6\n", __func__);
1871
1872         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1873                 pr_info("%s: can't deregister ip6ip6\n", __func__);
1874
1875         unregister_pernet_device(&ip6_tnl_net_ops);
1876 }
1877
1878 module_init(ip6_tunnel_init);
1879 module_exit(ip6_tunnel_cleanup);